/*
* IDE ATAPI streaming tape driver.
*
* Copyright (C) 1995-1999 Gadi Oxman <gadio@netvision.net.il>
* Copyright (C) 2003-2005 Bartlomiej Zolnierkiewicz
*
* This driver was constructed as a student project in the software laboratory
* of the faculty of electrical engineering in the Technion - Israel's
* Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
*
* It is hereby placed under the terms of the GNU general public license.
* (See linux/COPYING).
*
* For a historical changelog see
* Documentation/ide/ChangeLog.ide-tape.1995-2002
*/
#define IDETAPE_VERSION "1.19"
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/ide.h>
#include <linux/smp_lock.h>
#include <linux/completion.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
#include <scsi/scsi.h>
#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/unaligned.h>
#include <linux/mtio.h>
enum {
/* output errors only */
DBG_ERR = (1 << 0),
/* output all sense key/asc */
DBG_SENSE = (1 << 1),
/* info regarding all chrdev-related procedures */
DBG_CHRDEV = (1 << 2),
/* all remaining procedures */
DBG_PROCS = (1 << 3),
/* buffer alloc info (pc_stack & rq_stack) */
DBG_PCRQ_STACK = (1 << 4),
};
/* define to see debug info */
#define IDETAPE_DEBUG_LOG 0
#if IDETAPE_DEBUG_LOG
#define debug_log(lvl, fmt, args...) \
{ \
if (tape->debug_mask & lvl) \
printk(KERN_INFO "ide-tape: " fmt, ## args); \
}
#else
#define debug_log(lvl, fmt, args...) do {} while (0)
#endif
/**************************** Tunable parameters *****************************/
/*
* Pipelined mode parameters.
*
* We try to use the minimum number of stages which is enough to
* keep the tape constantly streaming. To accomplish that, we implement
* a feedback loop around the maximum number of stages:
*
* We start from MIN maximum stages (we will not even use MIN stages
* if we don't need them), increment it by RATE*(MAX-MIN)
* whenever we sense that the pipeline is empty, until we reach
* the optimum value or until we reach MAX.
*
* Setting the following parameter to 0 is illegal: the pipelined mode
* cannot be disabled (idetape_calculate_speeds() divides by
* tape->max_stages.)
*/
#define IDETAPE_MIN_PIPELINE_STAGES 1
#define IDETAPE_MAX_PIPELINE_STAGES 400
#define IDETAPE_INCREASE_STAGES_RATE 20
/*
* After each failed packet command we issue a request sense command
* and retry the packet command IDETAPE_MAX_PC_RETRIES times.
*
* Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
*/
#define IDETAPE_MAX_PC_RETRIES 3
/*
* With each packet command, we allocate a buffer of
* IDETAPE_PC_BUFFER_SIZE bytes. This is used for several packet
* commands (Not for READ/WRITE commands).
*/
#define IDETAPE_PC_BUFFER_SIZE 256
/*
* In various places in the driver, we need to allocate storage
* for packet commands and requests, which will remain valid while
* we leave the driver to wait for an interrupt or a timeout event.
*/
#define IDETAPE_PC_STACK (10 + IDETAPE_MAX_PC_RETRIES)
/*
* Some drives (for example, Seagate STT3401A Travan) require a very long
* timeout, because they don't return an interrupt or clear their busy bit
* until after the command completes (even retension commands).
*/
#define IDETAPE_WAIT_CMD (900*HZ)
/*
* The following parameter is used to select the point in the internal
* tape fifo in which we will start to refill the buffer. Decreasing
* the following parameter will improve the system's latency and
* interactive response, while using a high value might improve system
* throughput.
*/
#define IDETAPE_FIFO_THRESHOLD 2
/*
* DSC polling parameters.
*
* Polling for DSC (a single bit in the status register) is a very
* important function in ide-tape. There are two cases in which we
* poll for DSC:
*
* 1. Before a read/write packet command, to ensure that we
* can transfer data from/to the tape's data buffers, without
* causing an actual media access. In case the tape is not
* ready yet, we take out our request from the device
* request queue, so that ide.c will service requests from
* the other device on the same interface meanwhile.
*
* 2. After the successful initialization of a "media access
* packet command", which is a command which can take a long
* time to complete (it can be several seconds or even an hour).
*
* Again, we postpone our request in the middle to free the bus
* for the other device. The polling frequency here should be
* lower than the read/write frequency since those media access
* commands are slow. We start from a "fast" frequency -
* IDETAPE_DSC_MA_FAST (one second), and if we don't receive DSC
* after IDETAPE_DSC_MA_THRESHOLD (5 minutes), we switch it to a
* lower frequency - IDETAPE_DSC_MA_SLOW (1 minute).
*
* We also set a timeout for the timer, in case something goes wrong.
* The timeout should be longer then the maximum execution time of a
* tape operation.
*/
/*
* DSC timings.
*/
#define IDETAPE_DSC_RW_MIN 5*HZ/100 /* 50 msec */
#define IDETAPE_DSC_RW_MAX 40*HZ/100 /* 400 msec */
#define IDETAPE_DSC_RW_TIMEOUT 2*60*HZ /* 2 minutes */
#define IDETAPE_DSC_MA_FAST 2*HZ /* 2 seconds */
#define IDETAPE_DSC_MA_THRESHOLD 5*60*HZ /* 5 minutes */
#define IDETAPE_DSC_MA_SLOW 30*HZ /* 30 seconds */
#define IDETAPE_DSC_MA_TIMEOUT 2*60*60*HZ /* 2 hours */
/*************************** End of tunable parameters ***********************/
/*
* Read/Write error simulation
*/
#define SIMULATE_ERRORS 0
/*
* For general magnetic tape device compatibility.
*/
/* tape directions */
enum {
IDETAPE_DIR_NONE = (1 << 0),
IDETAPE_DIR_READ = (1 << 1),
IDETAPE_DIR_WRITE = (1 << 2),
};
struct idetape_bh {
u32 b_size;
atomic_t b_count;
struct idetape_bh *b_reqnext;
char *b_data;
};
/*
* Our view of a packet command.
*/
typedef struct idetape_packet_command_s {
u8 c[12]; /* Actual packet bytes */
int retries; /* On each retry, we increment retries */
int error; /* Error code */
int request_transfer; /* Bytes to transfer */
int actually_transferred; /* Bytes actually transferred */
int buffer_size; /* Size of our data buffer */
struct idetape_bh *bh;
char *b_data;
int b_count;
u8 *buffer; /* Data buffer */
u8 *current_position; /* Pointer into the above buffer */
ide_startstop_t (*callback) (ide_drive_t *); /* Called when this packet command is completed */
u8 pc_buffer[IDETAPE_PC_BUFFER_SIZE]; /* Temporary buffer */
unsigned long flags; /* Status/Action bit flags: long for set_bit */
} idetape_pc_t;
/*
* Packet command flag bits.
*/
/* Set when an error is considered normal - We won't retry */
#define PC_ABORT 0
/* 1 When polling for DSC on a media access command */
#define PC_WAIT_FOR_DSC 1
/* 1 when we prefer to use DMA if possible */
#define PC_DMA_RECOMMENDED 2
/* 1 while DMA in progress */
#define PC_DMA_IN_PROGRESS 3
/* 1 when encountered problem during DMA */
#define PC_DMA_ERROR 4
/* Data direction */
#define PC_WRITING 5
/*
* A pipeline stage.
*/
typedef struct idetape_stage_s {
struct request rq; /* The corresponding request */
struct idetape_bh *bh; /* The data buffers */
struct idetape_stage_s *next; /* Pointer to the next stage */
} idetape_stage_t;
/*
* Most of our global data which we need to save even as we leave the
* driver due to an interrupt or a timer event is stored in a variable
* of type idetape_tape_t, defined below.
*/
typedef struct ide_tape_obj {
ide_drive_t *drive;
ide_driver_t *driver;
struct gendisk *disk;
struct kref kref;
/*
* Since a typical character device operation requires more
* than one packet command, we provide here enough memory
* for the maximum of interconnected packet commands.
* The packet commands are stored in the circular array pc_stack.
* pc_stack_index points to the last used entry, and warps around
* to the start when we get to the last array entry.
*
* pc points to the current processed packet command.
*
* failed_pc points to the last failed packet command, or contains
* NULL if we do not need to retry any packet command. This is
* required since an additional packet command is needed before the
* retry, to get detailed information on what went wrong.
*/
/* Current packet command */
idetape_pc_t *pc;
/* Last failed packet command */
idetape_pc_t *failed_pc;
/* Packet command stack */
idetape_pc_t pc_stack[IDETAPE_PC_STACK];
/* Next free packet command storage space */
int pc_stack_index;
struct request rq_stack[IDETAPE_PC_STACK];
/* We implement a circular array */
int rq_stack_index;
/*
* DSC polling variables.
*
* While polling for DSC we use postponed_rq to postpone the
* current request so that ide.c will be able to service
* pending requests on the other device. Note that at most
* we will have only one DSC (usually data transfer) request
* in the device request queue. Additional requests can be
* queued in our internal pipeline, but they will be visible
* to ide.c only one at a time.
*/
struct request *postponed_rq;
/* The time in which we started polling for DSC */
unsigned long dsc_polling_start;
/* Timer used to poll for dsc */
struct timer_list dsc_timer;
/* Read/Write dsc polling frequency */
unsigned long best_dsc_rw_frequency;
/* The current polling frequency */
unsigned long dsc_polling_frequency;
/* Maximum waiting time */
unsigned long dsc_timeout;
/*
* Read position information
*/
u8 partition;
/* Current block */
unsigned int first_frame_position;
/*
* Last error information
*/
u8 sense_key, asc, ascq;
/*
* Character device operation
*/
unsigned int minor;
/* device name */
char name[4];
/* Current character device data transfer direction */
u8 chrdev_dir;
/*
* Device information
*/
/* Usually 512 or 1024 bytes */
unsigned short tape_block_size;
int user_bs_factor;
/* Copy of the tape's Capabilities and Mechanical Page */
u8 caps[20];
/*
* Active data transfer request parameters.
*
* At most, there is only one ide-tape originated data transfer
* request in the device request queue. This allows ide.c to
* easily service requests from the other device when we
* postpone our active request. In the pipelined operation
* mode, we use our internal pipeline structure to hold
* more data requests.
*
* The data buffer size is chosen based on the tape's
* recommendation.
*/
/* Pointer to the request which is waiting in the device request queue */
struct request *active_data_request;
/* Data buffer size (chosen based on the tape's recommendation */
int stage_size;
idetape_stage_t *merge_stage;
int merge_stage_size;
struct idetape_bh *bh;
char *b_data;
int b_count;
/*
* Pipeline parameters.
*
* To accomplish non-pipelined mode, we simply set the following
* variables to zero (or NULL, where appropriate).
*/
/* Number of currently used stages */
int nr_stages;
/* Number of pending stages */
int nr_pending_stages;
/* We will not allocate more than this number of stages */
int max_stages, min_pipeline, max_pipeline;
/* The first stage which will be removed from the pipeline */
idetape_stage_t *first_stage;
/* The currently active stage */
idetape_stage_t *active_stage;
/* Will be serviced after the currently active request */
idetape_stage_t *next_stage;
/* New requests will be added to the pipeline here */
idetape_stage_t *last_stage;
/* Optional free stage which we can use */
idetape_stage_t *cache_stage;
int pages_per_stage;
/* Wasted space in each stage */
int excess_bh_size;
/* Status/Action flags: long for set_bit */
unsigned long flags;
/* protects the ide-tape queue */
spinlock_t spinlock;
/*
* Measures average tape speed
*/
unsigned long avg_time;
int avg_size;
int avg_speed;
/* the door is currently locked */
int door_locked;
/* the tape hardware is write protected */
char drv_write_prot;
/* the tape is write protected (hardware or opened as read-only) */
char write_prot;
/*
* Limit the number of times a request can
* be postponed, to avoid an infinite postpone
* deadlock.
*/
/* request postpone count limit */
int postpone_cnt;
/*
* Measures number of frames:
*
* 1. written/read to/from the driver pipeline (pipeline_head).
* 2. written/read to/from the tape buffers (idetape_bh).
* 3. written/read by the tape to/from the media (tape_head).
*/
int pipeline_head;
int buffer_head;
int tape_head;
int last_tape_head;
/*
* Speed control at the tape buffers input/output
*/
unsigned long insert_time;
int insert_size;
int insert_speed;
int max_insert_speed;
int measure_insert_time;
/*
* Speed regulation negative feedback loop
*/
int speed_control;
int pipeline_head_speed;
int controlled_pipeline_head_speed;
int uncontrolled_pipeline_head_speed;
int controlled_last_pipeline_head;
unsigned long uncontrolled_pipeline_head_time;
unsigned long controlled_pipeline_head_time;
int controlled_previous_pipeline_head;
int uncontrolled_previous_pipeline_head;
unsigned long controlled_previous_head_time;
unsigned long uncontrolled_previous_head_time;
int restart_speed_control_req;
u32 debug_mask;
} idetape_tape_t;
static DEFINE_MUTEX(idetape_ref_mutex);
static struct class *idetape_sysfs_class;
#define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref)
#define ide_tape_g(disk) \
container_of((disk)->private_data, struct ide_tape_obj, driver)
static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
{
struct ide_tape_obj *tape = NULL;
mutex_lock(&idetape_ref_mutex);
tape = ide_tape_g(disk);
if (tape)
kref_get(&tape->kref);
mutex_unlock(&idetape_ref_mutex);
return tape;
}
static void ide_tape_release(struct kref *);
static void ide_tape_put(struct ide_tape_obj *tape)
{
mutex_lock(&idetape_ref_mutex);
kref_put(&tape->kref, ide_tape_release);
mutex_unlock(&idetape_ref_mutex);
}
/*
* Tape door status
*/
#define DOOR_UNLOCKED 0
#define DOOR_LOCKED 1
#define DOOR_EXPLICITLY_LOCKED 2
/*
* Tape flag bits values.
*/
#define IDETAPE_IGNORE_DSC 0
#define IDETAPE_ADDRESS_VALID 1 /* 0 When the tape position is unknown */
#define IDETAPE_BUSY 2 /* Device already opened */
#define IDETAPE_PIPELINE_ERROR 3 /* Error detected in a pipeline stage */
#define IDETAPE_DETECT_BS 4 /* Attempt to auto-detect the current user block size */
#define IDETAPE_FILEMARK 5 /* Currently on a filemark */
#define IDETAPE_DRQ_INTERRUPT 6 /* DRQ interrupt device */
#define IDETAPE_READ_ERROR 7
#define IDETAPE_PIPELINE_ACTIVE 8 /* pipeline active */
/* 0 = no tape is loaded, so we don't rewind after ejecting */
#define IDETAPE_MEDIUM_PRESENT 9
/*
* Some defines for the READ BUFFER command
*/
#define IDETAPE_RETRIEVE_FAULTY_BLOCK 6
/*
* Some defines for the SPACE command
*/
#define IDETAPE_SPACE_OVER_FILEMARK 1
#define IDETAPE_SPACE_TO_EOD 3
/*
* Some defines for the LOAD UNLOAD command
*/
#define IDETAPE_LU_LOAD_MASK 1
#define IDETAPE_LU_RETENSION_MASK 2
#define IDETAPE_LU_EOT_MASK 4
/*
* Special requests for our block device strategy routine.
*
* In order to service a character device command, we add special
* requests to the tail of our block device request queue and wait
* for their completion.
*/
enum {
REQ_IDETAPE_PC1 = (1 << 0), /* packet command (first stage) */
REQ_IDETAPE_PC2 = (1 << 1), /* packet command (second stage) */
REQ_IDETAPE_READ = (1 << 2),
REQ_IDETAPE_WRITE = (1 << 3),
REQ_IDETAPE_READ_BUFFER = (1 << 4),
};
/*
* Error codes which are returned in rq->errors to the higher part
* of the driver.
*/
#define IDETAPE_ERROR_GENERAL 101
#define IDETAPE_ERROR_FILEMARK 102
#define IDETAPE_ERROR_EOD 103
/*
* The following is used to format the general configuration word of
* the ATAPI IDENTIFY DEVICE command.
*/
struct idetape_id_gcw {
unsigned packet_size :2; /* Packet Size */
unsigned reserved234 :3; /* Reserved */
unsigned drq_type :2; /* Command packet DRQ type */
unsigned removable :1; /* Removable media */
unsigned device_type :5; /* Device type */
unsigned reserved13 :1; /* Reserved */
unsigned protocol :2; /* Protocol type */
};
/* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
#define IDETAPE_BLOCK_DESCRIPTOR 0
#define IDETAPE_CAPABILITIES_PAGE 0x2a
/*
* The variables below are used for the character device interface.
* Additional state variables are defined in our ide_drive_t structure.
*/
static struct ide_tape_obj * idetape_devs[MAX_HWIFS * MAX_DRIVES];
#define ide_tape_f(file) ((file)->private_data)
static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
{
struct ide_tape_obj *tape = NULL;
mutex_lock(&idetape_ref_mutex);
tape = idetape_devs[i];
if (tape)
kref_get(&tape->kref);
mutex_unlock(&idetape_ref_mutex);
return tape;
}
/*
* Function declarations
*
*/
static int idetape_chrdev_release (struct inode *inode, struct file *filp);
static void idetape_write_release (ide_drive_t *drive, unsigned int minor);
/*
* Too bad. The drive wants to send us data which we are not ready to accept.
* Just throw it away.
*/
static void idetape_discard_data (ide_drive_t *drive, unsigned int bcount)
{
while (bcount--)
(void) HWIF(drive)->INB(IDE_DATA_REG);
}
static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
{
struct idetape_bh *bh = pc->bh;
int count;
while (bcount) {
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_input_buffers\n");
idetape_discard_data(drive, bcount);
return;
}
count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), bcount);
HWIF(drive)->atapi_input_bytes(drive, bh->b_data + atomic_read(&bh->b_count), count);
bcount -= count;
atomic_add(count, &bh->b_count);
if (atomic_read(&bh->b_count) == bh->b_size) {
bh = bh->b_reqnext;
if (bh)
atomic_set(&bh->b_count, 0);
}
}
pc->bh = bh;
}
static void idetape_output_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
{
struct idetape_bh *bh = pc->bh;
int count;
while (bcount) {
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_output_buffers\n");
return;
}
count = min((unsigned int)pc->b_count, (unsigned int)bcount);
HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count);
bcount -= count;
pc->b_data += count;
pc->b_count -= count;
if (!pc->b_count) {
pc->bh = bh = bh->b_reqnext;
if (bh) {
pc->b_data = bh->b_data;
pc->b_count = atomic_read(&bh->b_count);
}
}
}
}
static void idetape_update_buffers (idetape_pc_t *pc)
{
struct idetape_bh *bh = pc->bh;
int count;
unsigned int bcount = pc->actually_transferred;
if (test_bit(PC_WRITING, &pc->flags))
return;
while (bcount) {
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_update_buffers\n");
return;
}
count = min((unsigned int)bh->b_size, (unsigned int)bcount);
atomic_set(&bh->b_count, count);
if (atomic_read(&bh->b_count) == bh->b_size)
bh = bh->b_reqnext;
bcount -= count;
}
pc->bh = bh;
}
/*
* idetape_next_pc_storage returns a pointer to a place in which we can
* safely store a packet command, even though we intend to leave the
* driver. A storage space for a maximum of IDETAPE_PC_STACK packet
* commands is allocated at initialization time.
*/
static idetape_pc_t *idetape_next_pc_storage (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
debug_log(DBG_PCRQ_STACK, "pc_stack_index=%d\n", tape->pc_stack_index);
if (tape->pc_stack_index == IDETAPE_PC_STACK)
tape->pc_stack_index=0;
return (&tape->pc_stack[tape->pc_stack_index++]);
}
/*
* idetape_next_rq_storage is used along with idetape_next_pc_storage.
* Since we queue packet commands in the request queue, we need to
* allocate a request, along with the allocation of a packet command.
*/
/**************************************************************
* *
* This should get fixed to use kmalloc(.., GFP_ATOMIC) *
* followed later on by kfree(). -ml *
* *
**************************************************************/
static struct request *idetape_next_rq_storage (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
debug_log(DBG_PCRQ_STACK, "rq_stack_index=%d\n", tape->rq_stack_index);
if (tape->rq_stack_index == IDETAPE_PC_STACK)
tape->rq_stack_index=0;
return (&tape->rq_stack[tape->rq_stack_index++]);
}
/*
* idetape_init_pc initializes a packet command.
*/
static void idetape_init_pc (idetape_pc_t *pc)
{
memset(pc->c, 0, 12);
pc->retries = 0;
pc->flags = 0;
pc->request_transfer = 0;
pc->buffer = pc->pc_buffer;
pc->buffer_size = IDETAPE_PC_BUFFER_SIZE;
pc->bh = NULL;
pc->b_data = NULL;
}
/*
* called on each failed packet command retry to analyze the request sense. We
* currently do not utilize this information.
*/
static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t *pc = tape->failed_pc;
tape->sense_key = sense[2] & 0xF;
tape->asc = sense[12];
tape->ascq = sense[13];
debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
pc->c[0], tape->sense_key, tape->asc, tape->ascq);
/* Correct pc->actually_transferred by asking the tape. */
if (test_bit(PC_DMA_ERROR, &pc->flags)) {
pc->actually_transferred = pc->request_transfer -
tape->tape_block_size *
be32_to_cpu(get_unaligned((u32 *)&sense[3]));
idetape_update_buffers(pc);
}
/*
* If error was the result of a zero-length read or write command,
* with sense key=5, asc=0x22, ascq=0, let it slide. Some drives
* (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
*/
if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
/* length == 0 */
&& pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
if (tape->sense_key == 5) {
/* don't report an error, everything's ok */
pc->error = 0;
/* don't retry read/write */
set_bit(PC_ABORT, &pc->flags);
}
}
if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
pc->error = IDETAPE_ERROR_FILEMARK;
set_bit(PC_ABORT, &pc->flags);
}
if (pc->c[0] == WRITE_6) {
if ((sense[2] & 0x40) || (tape->sense_key == 0xd
&& tape->asc == 0x0 && tape->ascq == 0x2)) {
pc->error = IDETAPE_ERROR_EOD;
set_bit(PC_ABORT, &pc->flags);
}
}
if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
if (tape->sense_key == 8) {
pc->error = IDETAPE_ERROR_EOD;
set_bit(PC_ABORT, &pc->flags);
}
if (!test_bit(PC_ABORT, &pc->flags) &&
pc->actually_transferred)
pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
}
}
static void idetape_activate_next_stage(ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_stage_t *stage = tape->next_stage;
struct request *rq = &stage->rq;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
if (stage == NULL) {
printk(KERN_ERR "ide-tape: bug: Trying to activate a non"
" existing stage\n");
return;
}
rq->rq_disk = tape->disk;
rq->buffer = NULL;
rq->special = (void *)stage->bh;
tape->active_data_request = rq;
tape->active_stage = stage;
tape->next_stage = stage->next;
}
/*
* idetape_increase_max_pipeline_stages is a part of the feedback
* loop which tries to find the optimum number of stages. In the
* feedback loop, we are starting from a minimum maximum number of
* stages, and if we sense that the pipeline is empty, we try to
* increase it, until we reach the user compile time memory limit.
*/
static void idetape_increase_max_pipeline_stages (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
int increase = (tape->max_pipeline - tape->min_pipeline) / 10;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
tape->max_stages += max(increase, 1);
tape->max_stages = max(tape->max_stages, tape->min_pipeline);
tape->max_stages = min(tape->max_stages, tape->max_pipeline);
}
/*
* idetape_kfree_stage calls kfree to completely free a stage, along with
* its related buffers.
*/
static void __idetape_kfree_stage (idetape_stage_t *stage)
{
struct idetape_bh *prev_bh, *bh = stage->bh;
int size;
while (bh != NULL) {
if (bh->b_data != NULL) {
size = (int) bh->b_size;
while (size > 0) {
free_page((unsigned long) bh->b_data);
size -= PAGE_SIZE;
bh->b_data += PAGE_SIZE;
}
}
prev_bh = bh;
bh = bh->b_reqnext;
kfree(prev_bh);
}
kfree(stage);
}
static void idetape_kfree_stage (idetape_tape_t *tape, idetape_stage_t *stage)
{
__idetape_kfree_stage(stage);
}
/*
* idetape_remove_stage_head removes tape->first_stage from the pipeline.
* The caller should avoid race conditions.
*/
static void idetape_remove_stage_head (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_stage_t *stage;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
if (tape->first_stage == NULL) {
printk(KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n");
return;
}
if (tape->active_stage == tape->first_stage) {
printk(KERN_ERR "ide-tape: bug: Trying to free our active "
"pipeline stage\n");
return;
}
stage = tape->first_stage;
tape->first_stage = stage->next;
idetape_kfree_stage(tape, stage);
tape->nr_stages--;
if (tape->first_stage == NULL) {
tape->last_stage = NULL;
if (tape->next_stage != NULL)
printk(KERN_ERR "ide-tape: bug: tape->next_stage != NULL\n");
if (tape->nr_stages)
printk(KERN_ERR "ide-tape: bug: nr_stages should be 0 now\n");
}
}
/*
* This will free all the pipeline stages starting from new_last_stage->next
* to the end of the list, and point tape->last_stage to new_last_stage.
*/
static void idetape_abort_pipeline(ide_drive_t *drive,
idetape_stage_t *new_last_stage)
{
idetape_tape_t *tape = drive->driver_data;
idetape_stage_t *stage = new_last_stage->next;
idetape_stage_t *nstage;
debug_log(DBG_PROCS, "%s: Enter %s\n", tape->name, __func__);
while (stage) {
nstage = stage->next;
idetape_kfree_stage(tape, stage);
--tape->nr_stages;
--tape->nr_pending_stages;
stage = nstage;
}
if (new_last_stage)
new_last_stage->next = NULL;
tape->last_stage = new_last_stage;
tape->next_stage = NULL;
}
/*
* idetape_end_request is used to finish servicing a request, and to
* insert a pending pipeline request into the main device queue.
*/
static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
{
struct request *rq = HWGROUP(drive)->rq;
idetape_tape_t *tape = drive->driver_data;
unsigned long flags;
int error;
int remove_stage = 0;
idetape_stage_t *active_stage;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
switch (uptodate) {
case 0: error = IDETAPE_ERROR_GENERAL; break;
case 1: error = 0; break;
default: error = uptodate;
}
rq->errors = error;
if (error)
tape->failed_pc = NULL;
if (!blk_special_request(rq)) {
ide_end_request(drive, uptodate, nr_sects);
return 0;
}
spin_lock_irqsave(&tape->spinlock, flags);
/* The request was a pipelined data transfer request */
if (tape->active_data_request == rq) {
active_stage = tape->active_stage;
tape->active_stage = NULL;
tape->active_data_request = NULL;
tape->nr_pending_stages--;
if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
remove_stage = 1;
if (error) {
set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
if (error == IDETAPE_ERROR_EOD)
idetape_abort_pipeline(drive, active_stage);
}
} else if (rq->cmd[0] & REQ_IDETAPE_READ) {
if (error == IDETAPE_ERROR_EOD) {
set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
idetape_abort_pipeline(drive, active_stage);
}
}
if (tape->next_stage != NULL) {
idetape_activate_next_stage(drive);
/*
* Insert the next request into the request queue.
*/
(void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end);
} else if (!error) {
idetape_increase_max_pipeline_stages(drive);
}
}
ide_end_drive_cmd(drive, 0, 0);
// blkdev_dequeue_request(rq);
// drive->rq = NULL;
// end_that_request_last(rq);
if (remove_stage)
idetape_remove_stage_head(drive);
if (tape->active_data_request == NULL)
clear_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
spin_unlock_irqrestore(&tape->spinlock, flags);
return 0;
}
static ide_startstop_t idetape_request_sense_callback (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
if (!tape->pc->error) {
idetape_analyze_error(drive, tape->pc->buffer);
idetape_end_request(drive, 1, 0);
} else {
printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - Aborting request!\n");
idetape_end_request(drive, 0, 0);
}
return ide_stopped;
}
static void idetape_create_request_sense_cmd (idetape_pc_t *pc)
{
idetape_init_pc(pc);
pc->c[0] = REQUEST_SENSE;
pc->c[4] = 20;
pc->request_transfer = 20;
pc->callback = &idetape_request_sense_callback;
}
static void idetape_init_rq(struct request *rq, u8 cmd)
{
memset(rq, 0, sizeof(*rq));
rq->cmd_type = REQ_TYPE_SPECIAL;
rq->cmd[0] = cmd;
}
/*
* idetape_queue_pc_head generates a new packet command request in front
* of the request queue, before the current request, so that it will be
* processed immediately, on the next pass through the driver.
*
* idetape_queue_pc_head is called from the request handling part of
* the driver (the "bottom" part). Safe storage for the request should
* be allocated with idetape_next_pc_storage and idetape_next_rq_storage
* before calling idetape_queue_pc_head.
*
* Memory for those requests is pre-allocated at initialization time, and
* is limited to IDETAPE_PC_STACK requests. We assume that we have enough
* space for the maximum possible number of inter-dependent packet commands.
*
* The higher level of the driver - The ioctl handler and the character
* device handling functions should queue request to the lower level part
* and wait for their completion using idetape_queue_pc_tail or
* idetape_queue_rw_tail.
*/
static void idetape_queue_pc_head (ide_drive_t *drive, idetape_pc_t *pc,struct request *rq)
{
struct ide_tape_obj *tape = drive->driver_data;
idetape_init_rq(rq, REQ_IDETAPE_PC1);
rq->buffer = (char *) pc;
rq->rq_disk = tape->disk;
(void) ide_do_drive_cmd(drive, rq, ide_preempt);
}
/*
* idetape_retry_pc is called when an error was detected during the
* last packet command. We queue a request sense packet command in
* the head of the request list.
*/
static ide_startstop_t idetape_retry_pc (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t *pc;
struct request *rq;
(void)ide_read_error(drive);
pc = idetape_next_pc_storage(drive);
rq = idetape_next_rq_storage(drive);
idetape_create_request_sense_cmd(pc);
set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
idetape_queue_pc_head(drive, pc, rq);
return ide_stopped;
}
/*
* idetape_postpone_request postpones the current request so that
* ide.c will be able to service requests from another device on
* the same hwgroup while we are polling for DSC.
*/
static void idetape_postpone_request (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
tape->postponed_rq = HWGROUP(drive)->rq;
ide_stall_queue(drive, tape->dsc_polling_frequency);
}
typedef void idetape_io_buf(ide_drive_t *, idetape_pc_t *, unsigned int);
/*
* This is the usual interrupt handler which will be called during a packet
* command. We will transfer some of the data (as requested by the drive) and
* will re-point interrupt handler to us. When data transfer is finished, we
* will act according to the algorithm described before
* idetape_issue_packet_command.
*/
static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
{
ide_hwif_t *hwif = drive->hwif;
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t *pc = tape->pc;
xfer_func_t *xferfunc;
idetape_io_buf *iobuf;
unsigned int temp;
#if SIMULATE_ERRORS
static int error_sim_count = 0;
#endif
u16 bcount;
u8 stat, ireason;
debug_log(DBG_PROCS, "Enter %s - interrupt handler\n", __func__);
/* Clear the interrupt */
stat = ide_read_status(drive);
if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
if (hwif->ide_dma_end(drive) || (stat & ERR_STAT)) {
/*
* A DMA error is sometimes expected. For example,
* if the tape is crossing a filemark during a
* READ command, it will issue an irq and position
* itself before the filemark, so that only a partial
* data transfer will occur (which causes the DMA
* error). In that case, we will later ask the tape
* how much bytes of the original request were
* actually transferred (we can't receive that
* information from the DMA engine on most chipsets).
*/
/*
* On the contrary, a DMA error is never expected;
* it usually indicates a hardware error or abort.
* If the tape crosses a filemark during a READ
* command, it will issue an irq and position itself
* after the filemark (not before). Only a partial
* data transfer will occur, but no DMA error.
* (AS, 19 Apr 2001)
*/
set_bit(PC_DMA_ERROR, &pc->flags);
} else {
pc->actually_transferred = pc->request_transfer;
idetape_update_buffers(pc);
}
debug_log(DBG_PROCS, "DMA finished\n");
}
/* No more interrupts */
if ((stat & DRQ_STAT) == 0) {
debug_log(DBG_SENSE, "Packet command completed, %d bytes"
" transferred\n", pc->actually_transferred);
clear_bit(PC_DMA_IN_PROGRESS, &pc->flags);
local_irq_enable();
#if SIMULATE_ERRORS
if ((pc->c[0] == WRITE_6 || pc->c[0] == READ_6) &&
(++error_sim_count % 100) == 0) {
printk(KERN_INFO "ide-tape: %s: simulating error\n",
tape->name);
stat |= ERR_STAT;
}
#endif
if ((stat & ERR_STAT) && pc->c[0] == REQUEST_SENSE)
stat &= ~ERR_STAT;
if ((stat & ERR_STAT) || test_bit(PC_DMA_ERROR, &pc->flags)) {
/* Error detected */
debug_log(DBG_ERR, "%s: I/O error\n", tape->name);
if (pc->c[0] == REQUEST_SENSE) {
printk(KERN_ERR "ide-tape: I/O error in request"
" sense command\n");
return ide_do_reset(drive);
}
debug_log(DBG_ERR, "[cmd %x]: check condition\n",
pc->c[0]);
/* Retry operation */
return idetape_retry_pc(drive);
}
pc->error = 0;
if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) &&
(stat & SEEK_STAT) == 0) {
/* Media access command */
tape->dsc_polling_start = jiffies;
tape->dsc_polling_frequency = IDETAPE_DSC_MA_FAST;
tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
/* Allow ide.c to handle other requests */
idetape_postpone_request(drive);
return ide_stopped;
}
if (tape->failed_pc == pc)
tape->failed_pc = NULL;
/* Command finished - Call the callback function */
return pc->callback(drive);
}
if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
printk(KERN_ERR "ide-tape: The tape wants to issue more "
"interrupts in DMA mode\n");
printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n");
ide_dma_off(drive);
return ide_do_reset(drive);
}
/* Get the number of bytes to transfer on this interrupt. */
bcount = (hwif->INB(IDE_BCOUNTH_REG) << 8) |
hwif->INB(IDE_BCOUNTL_REG);
ireason = hwif->INB(IDE_IREASON_REG);
if (ireason & CD) {
printk(KERN_ERR "ide-tape: CoD != 0 in %s\n", __func__);
return ide_do_reset(drive);
}
if (((ireason & IO) == IO) == test_bit(PC_WRITING, &pc->flags)) {
/* Hopefully, we will never get here */
printk(KERN_ERR "ide-tape: We wanted to %s, ",
(ireason & IO) ? "Write" : "Read");
printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n",
(ireason & IO) ? "Read" : "Write");
return ide_do_reset(drive);
}
if (!test_bit(PC_WRITING, &pc->flags)) {
/* Reading - Check that we have enough space */
temp = pc->actually_transferred + bcount;
if (temp > pc->request_transfer) {
if (temp > pc->buffer_size) {
printk(KERN_ERR "ide-tape: The tape wants to "
"send us more data than expected "
"- discarding data\n");
idetape_discard_data(drive, bcount);
ide_set_handler(drive, &idetape_pc_intr,
IDETAPE_WAIT_CMD, NULL);
return ide_started;
}
debug_log(DBG_SENSE, "The tape wants to send us more "
"data than expected - allowing transfer\n");
}
iobuf = &idetape_input_buffers;
xferfunc = hwif->atapi_input_bytes;
} else {
iobuf = &idetape_output_buffers;
xferfunc = hwif->atapi_output_bytes;
}
if (pc->bh)
iobuf(drive, pc, bcount);
else
xferfunc(drive, pc->current_position, bcount);
/* Update the current position */
pc->actually_transferred += bcount;
pc->current_position += bcount;
debug_log(DBG_SENSE, "[cmd %x] transferred %d bytes on that intr.\n",
pc->c[0], bcount);
/* And set the interrupt handler again */
ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
return ide_started;
}
/*
* Packet Command Interface
*
* The current Packet Command is available in tape->pc, and will not
* change until we finish handling it. Each packet command is associated
* with a callback function that will be called when the command is
* finished.
*
* The handling will be done in three stages:
*
* 1. idetape_issue_packet_command will send the packet command to the
* drive, and will set the interrupt handler to idetape_pc_intr.
*
* 2. On each interrupt, idetape_pc_intr will be called. This step
* will be repeated until the device signals us that no more
* interrupts will be issued.
*
* 3. ATAPI Tape media access commands have immediate status with a
* delayed process. In case of a successful initiation of a
* media access packet command, the DSC bit will be set when the
* actual execution of the command is finished.
* Since the tape drive will not issue an interrupt, we have to
* poll for this event. In this case, we define the request as
* "low priority request" by setting rq_status to
* IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and exit
* the driver.
*
* ide.c will then give higher priority to requests which
* originate from the other device, until will change rq_status
* to RQ_ACTIVE.
*
* 4. When the packet command is finished, it will be checked for errors.
*
* 5. In case an error was found, we queue a request sense packet
* command in front of the request queue and retry the operation
* up to IDETAPE_MAX_PC_RETRIES times.
*
* 6. In case no error was found, or we decided to give up and not
* to retry again, the callback function will be called and then
* we will handle the next request.
*
*/
static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
{
ide_hwif_t *hwif = drive->hwif;
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t *pc = tape->pc;
int retries = 100;
ide_startstop_t startstop;
u8 ireason;
if (ide_wait_stat(&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) {
printk(KERN_ERR "ide-tape: Strange, packet command initiated yet DRQ isn't asserted\n");
return startstop;
}
ireason = hwif->INB(IDE_IREASON_REG);
while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) {
printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing "
"a packet command, retrying\n");
udelay(100);
ireason = hwif->INB(IDE_IREASON_REG);
if (retries == 0) {
printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while "
"issuing a packet command, ignoring\n");
ireason |= CD;
ireason &= ~IO;
}
}
if ((ireason & CD) == 0 || (ireason & IO)) {
printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing "
"a packet command\n");
return ide_do_reset(drive);
}
/* Set the interrupt routine */
ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
#ifdef CONFIG_BLK_DEV_IDEDMA
/* Begin DMA, if necessary */
if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags))
hwif->dma_start(drive);
#endif
/* Send the actual packet */
HWIF(drive)->atapi_output_bytes(drive, pc->c, 12);
return ide_started;
}
static ide_startstop_t idetape_issue_packet_command (ide_drive_t *drive, idetape_pc_t *pc)
{
ide_hwif_t *hwif = drive->hwif;
idetape_tape_t *tape = drive->driver_data;
int dma_ok = 0;
u16 bcount;
if (tape->pc->c[0] == REQUEST_SENSE &&
pc->c[0] == REQUEST_SENSE) {
printk(KERN_ERR "ide-tape: possible ide-tape.c bug - "
"Two request sense in serial were issued\n");
}
if (tape->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
tape->failed_pc = pc;
/* Set the current packet command */
tape->pc = pc;
if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
test_bit(PC_ABORT, &pc->flags)) {
/*
* We will "abort" retrying a packet command in case
* a legitimate error code was received (crossing a
* filemark, or end of the media, for example).
*/
if (!test_bit(PC_ABORT, &pc->flags)) {
if (!(pc->c[0] == TEST_UNIT_READY &&
tape->sense_key == 2 && tape->asc == 4 &&
(tape->ascq == 1 || tape->ascq == 8))) {
printk(KERN_ERR "ide-tape: %s: I/O error, "
"pc = %2x, key = %2x, "
"asc = %2x, ascq = %2x\n",
tape->name, pc->c[0],
tape->sense_key, tape->asc,
tape->ascq);
}
/* Giving up */
pc->error = IDETAPE_ERROR_GENERAL;
}
tape->failed_pc = NULL;
return pc->callback(drive);
}
debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
pc->retries++;
/* We haven't transferred any data yet */
pc->actually_transferred = 0;
pc->current_position = pc->buffer;
/* Request to transfer the entire buffer at once */
bcount = pc->request_transfer;
if (test_and_clear_bit(PC_DMA_ERROR, &pc->flags)) {
printk(KERN_WARNING "ide-tape: DMA disabled, "
"reverting to PIO\n");
ide_dma_off(drive);
}
if (test_bit(PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma)
dma_ok = !hwif->dma_setup(drive);
ide_pktcmd_tf_load(drive, IDE_TFLAG_NO_SELECT_MASK |
IDE_TFLAG_OUT_DEVICE, bcount, dma_ok);
if (dma_ok) /* Will begin DMA later */
set_bit(PC_DMA_IN_PROGRESS, &pc->flags);
if (test_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags)) {
ide_execute_command(drive, WIN_PACKETCMD, &idetape_transfer_pc,
IDETAPE_WAIT_CMD, NULL);
return ide_started;
} else {
hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
return idetape_transfer_pc(drive);
}
}
/*
* General packet command callback function.
*/
static ide_startstop_t idetape_pc_callback (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
idetape_end_request(drive, tape->pc->error ? 0 : 1, 0);
return ide_stopped;
}
/*
* A mode sense command is used to "sense" tape parameters.
*/
static void idetape_create_mode_sense_cmd (idetape_pc_t *pc, u8 page_code)
{
idetape_init_pc(pc);
pc->c[0] = MODE_SENSE;
if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
pc->c[1] = 8; /* DBD = 1 - Don't return block descriptors */
pc->c[2] = page_code;
/*
* Changed pc->c[3] to 0 (255 will at best return unused info).
*
* For SCSI this byte is defined as subpage instead of high byte
* of length and some IDE drives seem to interpret it this way
* and return an error when 255 is used.
*/
pc->c[3] = 0;
pc->c[4] = 255; /* (We will just discard data in that case) */
if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
pc->request_transfer = 12;
else if (page_code == IDETAPE_CAPABILITIES_PAGE)
pc->request_transfer = 24;
else
pc->request_transfer = 50;
pc->callback = &idetape_pc_callback;
}
static void idetape_calculate_speeds(ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
if (time_after(jiffies, tape->controlled_pipeline_head_time + 120 * HZ)) {
tape->controlled_previous_pipeline_head = tape->controlled_last_pipeline_head;
tape->controlled_previous_head_time = tape->controlled_pipeline_head_time;
tape->controlled_last_pipeline_head = tape->pipeline_head;
tape->controlled_pipeline_head_time = jiffies;
}
if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ))
tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_last_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_pipeline_head_time);
else if (time_after(jiffies, tape->controlled_previous_head_time))
tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_previous_head_time);
if (tape->nr_pending_stages < tape->max_stages /*- 1 */) {
/* -1 for read mode error recovery */
if (time_after(jiffies, tape->uncontrolled_previous_head_time + 10 * HZ)) {
tape->uncontrolled_pipeline_head_time = jiffies;
tape->uncontrolled_pipeline_head_speed = (tape->pipeline_head - tape->uncontrolled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->uncontrolled_previous_head_time);
}
} else {
tape->uncontrolled_previous_head_time = jiffies;
tape->uncontrolled_previous_pipeline_head = tape->pipeline_head;
if (time_after(jiffies, tape->uncontrolled_pipeline_head_time + 30 * HZ)) {
tape->uncontrolled_pipeline_head_time = jiffies;
}
}
tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed, tape->controlled_pipeline_head_speed);
if (tape->speed_control == 1) {
if (tape->nr_pending_stages >= tape->max_stages / 2)
tape->max_insert_speed = tape->pipeline_head_speed +
(1100 - tape->pipeline_head_speed) * 2 * (tape->nr_pending_stages - tape->max_stages / 2) / tape->max_stages;
else
tape->max_insert_speed = 500 +
(tape->pipeline_head_speed - 500) * 2 * tape->nr_pending_stages / tape->max_stages;
if (tape->nr_pending_stages >= tape->max_stages * 99 / 100)
tape->max_insert_speed = 5000;
} else
tape->max_insert_speed = tape->speed_control;
tape->max_insert_speed = max(tape->max_insert_speed, 500);
}
static ide_startstop_t idetape_media_access_finished (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t *pc = tape->pc;
u8 stat;
stat = ide_read_status(drive);
if (stat & SEEK_STAT) {
if (stat & ERR_STAT) {
/* Error detected */
if (pc->c[0] != TEST_UNIT_READY)
printk(KERN_ERR "ide-tape: %s: I/O error, ",
tape->name);
/* Retry operation */
return idetape_retry_pc(drive);
}
pc->error = 0;
if (tape->failed_pc == pc)
tape->failed_pc = NULL;
} else {
pc->error = IDETAPE_ERROR_GENERAL;
tape->failed_pc = NULL;
}
return pc->callback(drive);
}
static ide_startstop_t idetape_rw_callback (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
struct request *rq = HWGROUP(drive)->rq;
int blocks = tape->pc->actually_transferred / tape->tape_block_size;
tape->avg_size += blocks * tape->tape_block_size;
tape->insert_size += blocks * tape->tape_block_size;
if (tape->insert_size > 1024 * 1024)
tape->measure_insert_time = 1;
if (tape->measure_insert_time) {
tape->measure_insert_time = 0;
tape->insert_time = jiffies;
tape->insert_size = 0;
}
if (time_after(jiffies, tape->insert_time))
tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
if (time_after_eq(jiffies, tape->avg_time + HZ)) {
tape->avg_speed = tape->avg_size * HZ / (jiffies - tape->avg_time) / 1024;
tape->avg_size = 0;
tape->avg_time = jiffies;
}
debug_log(DBG_PROCS, "Enter %s\n", __func__);
tape->first_frame_position += blocks;
rq->current_nr_sectors -= blocks;
if (!tape->pc->error)
idetape_end_request(drive, 1, 0);
else
idetape_end_request(drive, tape->pc->error, 0);
return ide_stopped;
}
static void idetape_create_read_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
{
idetape_init_pc(pc);
pc->c[0] = READ_6;
put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
pc->c[1] = 1;
pc->callback = &idetape_rw_callback;
pc->bh = bh;
atomic_set(&bh->b_count, 0);
pc->buffer = NULL;
pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
if (pc->request_transfer == tape->stage_size)
set_bit(PC_DMA_RECOMMENDED, &pc->flags);
}
static void idetape_create_read_buffer_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
{
int size = 32768;
struct idetape_bh *p = bh;
idetape_init_pc(pc);
pc->c[0] = READ_BUFFER;
pc->c[1] = IDETAPE_RETRIEVE_FAULTY_BLOCK;
pc->c[7] = size >> 8;
pc->c[8] = size & 0xff;
pc->callback = &idetape_pc_callback;
pc->bh = bh;
atomic_set(&bh->b_count, 0);
pc->buffer = NULL;
while (p) {
atomic_set(&p->b_count, 0);
p = p->b_reqnext;
}
pc->request_transfer = pc->buffer_size = size;
}
static void idetape_create_write_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
{
idetape_init_pc(pc);
pc->c[0] = WRITE_6;
put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
pc->c[1] = 1;
pc->callback = &idetape_rw_callback;
set_bit(PC_WRITING, &pc->flags);
pc->bh = bh;
pc->b_data = bh->b_data;
pc->b_count = atomic_read(&bh->b_count);
pc->buffer = NULL;
pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
if (pc->request_transfer == tape->stage_size)
set_bit(PC_DMA_RECOMMENDED, &pc->flags);
}
/*
* idetape_do_request is our request handling function.
*/
static ide_startstop_t idetape_do_request(ide_drive_t *drive,
struct request *rq, sector_t block)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t *pc = NULL;
struct request *postponed_rq = tape->postponed_rq;
u8 stat;
debug_log(DBG_SENSE, "sector: %ld, nr_sectors: %ld,"
" current_nr_sectors: %d\n",
rq->sector, rq->nr_sectors, rq->current_nr_sectors);
if (!blk_special_request(rq)) {
/*
* We do not support buffer cache originated requests.
*/
printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
"request queue (%d)\n", drive->name, rq->cmd_type);
ide_end_request(drive, 0, 0);
return ide_stopped;
}
/*
* Retry a failed packet command
*/
if (tape->failed_pc != NULL &&
tape->pc->c[0] == REQUEST_SENSE) {
return idetape_issue_packet_command(drive, tape->failed_pc);
}
if (postponed_rq != NULL)
if (rq != postponed_rq) {
printk(KERN_ERR "ide-tape: ide-tape.c bug - "
"Two DSC requests were queued\n");
idetape_end_request(drive, 0, 0);
return ide_stopped;
}
tape->postponed_rq = NULL;
/*
* If the tape is still busy, postpone our request and service
* the other device meanwhile.
*/
stat = ide_read_status(drive);
if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2))
set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
if (drive->post_reset == 1) {
set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
drive->post_reset = 0;
}
if (time_after(jiffies, tape->insert_time))
tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
idetape_calculate_speeds(drive);
if (!test_and_clear_bit(IDETAPE_IGNORE_DSC, &tape->flags) &&
(stat & SEEK_STAT) == 0) {
if (postponed_rq == NULL) {
tape->dsc_polling_start = jiffies;
tape->dsc_polling_frequency = tape->best_dsc_rw_frequency;
tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
} else if (time_after(jiffies, tape->dsc_timeout)) {
printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
tape->name);
if (rq->cmd[0] & REQ_IDETAPE_PC2) {
idetape_media_access_finished(drive);
return ide_stopped;
} else {
return ide_do_reset(drive);
}
} else if (time_after(jiffies, tape->dsc_polling_start + IDETAPE_DSC_MA_THRESHOLD))
tape->dsc_polling_frequency = IDETAPE_DSC_MA_SLOW;
idetape_postpone_request(drive);
return ide_stopped;
}
if (rq->cmd[0] & REQ_IDETAPE_READ) {
tape->buffer_head++;
tape->postpone_cnt = 0;
pc = idetape_next_pc_storage(drive);
idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
goto out;
}
if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
tape->buffer_head++;
tape->postpone_cnt = 0;
pc = idetape_next_pc_storage(drive);
idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
goto out;
}
if (rq->cmd[0] & REQ_IDETAPE_READ_BUFFER) {
tape->postpone_cnt = 0;
pc = idetape_next_pc_storage(drive);
idetape_create_read_buffer_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
goto out;
}
if (rq->cmd[0] & REQ_IDETAPE_PC1) {
pc = (idetape_pc_t *) rq->buffer;
rq->cmd[0] &= ~(REQ_IDETAPE_PC1);
rq->cmd[0] |= REQ_IDETAPE_PC2;
goto out;
}
if (rq->cmd[0] & REQ_IDETAPE_PC2) {
idetape_media_access_finished(drive);
return ide_stopped;
}
BUG();
out:
return idetape_issue_packet_command(drive, pc);
}
/*
* Pipeline related functions
*/
static inline int idetape_pipeline_active (idetape_tape_t *tape)
{
int rc1, rc2;
rc1 = test_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
rc2 = (tape->active_data_request != NULL);
return rc1;
}
/*
* idetape_kmalloc_stage uses __get_free_page to allocate a pipeline
* stage, along with all the necessary small buffers which together make
* a buffer of size tape->stage_size (or a bit more). We attempt to
* combine sequential pages as much as possible.
*
* Returns a pointer to the new allocated stage, or NULL if we
* can't (or don't want to) allocate a stage.
*
* Pipeline stages are optional and are used to increase performance.
* If we can't allocate them, we'll manage without them.
*/
static idetape_stage_t *__idetape_kmalloc_stage (idetape_tape_t *tape, int full, int clear)
{
idetape_stage_t *stage;
struct idetape_bh *prev_bh, *bh;
int pages = tape->pages_per_stage;
char *b_data = NULL;
if ((stage = kmalloc(sizeof (idetape_stage_t),GFP_KERNEL)) == NULL)
return NULL;
stage->next = NULL;
bh = stage->bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
if (bh == NULL)
goto abort;
bh->b_reqnext = NULL;
if ((bh->b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
goto abort;
if (clear)
memset(bh->b_data, 0, PAGE_SIZE);
bh->b_size = PAGE_SIZE;
atomic_set(&bh->b_count, full ? bh->b_size : 0);
while (--pages) {
if ((b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
goto abort;
if (clear)
memset(b_data, 0, PAGE_SIZE);
if (bh->b_data == b_data + PAGE_SIZE) {
bh->b_size += PAGE_SIZE;
bh->b_data -= PAGE_SIZE;
if (full)
atomic_add(PAGE_SIZE, &bh->b_count);
continue;
}
if (b_data == bh->b_data + bh->b_size) {
bh->b_size += PAGE_SIZE;
if (full)
atomic_add(PAGE_SIZE, &bh->b_count);
continue;
}
prev_bh = bh;
if ((bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL)) == NULL) {
free_page((unsigned long) b_data);
goto abort;
}
bh->b_reqnext = NULL;
bh->b_data = b_data;
bh->b_size = PAGE_SIZE;
atomic_set(&bh->b_count, full ? bh->b_size : 0);
prev_bh->b_reqnext = bh;
}
bh->b_size -= tape->excess_bh_size;
if (full)
atomic_sub(tape->excess_bh_size, &bh->b_count);
return stage;
abort:
__idetape_kfree_stage(stage);
return NULL;
}
static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape)
{
idetape_stage_t *cache_stage = tape->cache_stage;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
if (tape->nr_stages >= tape->max_stages)
return NULL;
if (cache_stage != NULL) {
tape->cache_stage = NULL;
return cache_stage;
}
return __idetape_kmalloc_stage(tape, 0, 0);
}
static int idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)
{
struct idetape_bh *bh = tape->bh;
int count;
int ret = 0;
while (n) {
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_copy_stage_from_user\n");
return 1;
}
count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n);
if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count))
ret = 1;
n -= count;
atomic_add(count, &bh->b_count);
buf += count;
if (atomic_read(&bh->b_count) == bh->b_size) {
bh = bh->b_reqnext;
if (bh)
atomic_set(&bh->b_count, 0);
}
}
tape->bh = bh;
return ret;
}
static int idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)
{
struct idetape_bh *bh = tape->bh;
int count;
int ret = 0;
while (n) {
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_copy_stage_to_user\n");
return 1;
}
count = min(tape->b_count, n);
if (copy_to_user(buf, tape->b_data, count))
ret = 1;
n -= count;
tape->b_data += count;
tape->b_count -= count;
buf += count;
if (!tape->b_count) {
tape->bh = bh = bh->b_reqnext;
if (bh) {
tape->b_data = bh->b_data;
tape->b_count = atomic_read(&bh->b_count);
}
}
}
return ret;
}
static void idetape_init_merge_stage (idetape_tape_t *tape)
{
struct idetape_bh *bh = tape->merge_stage->bh;
tape->bh = bh;
if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
atomic_set(&bh->b_count, 0);
else {
tape->b_data = bh->b_data;
tape->b_count = atomic_read(&bh->b_count);
}
}
static void idetape_switch_buffers (idetape_tape_t *tape, idetape_stage_t *stage)
{
struct idetape_bh *tmp;
tmp = stage->bh;
stage->bh = tape->merge_stage->bh;
tape->merge_stage->bh = tmp;
idetape_init_merge_stage(tape);
}
/*
* idetape_add_stage_tail adds a new stage at the end of the pipeline.
*/
static void idetape_add_stage_tail (ide_drive_t *drive,idetape_stage_t *stage)
{
idetape_tape_t *tape = drive->driver_data;
unsigned long flags;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
spin_lock_irqsave(&tape->spinlock, flags);
stage->next = NULL;
if (tape->last_stage != NULL)
tape->last_stage->next=stage;
else
tape->first_stage = tape->next_stage=stage;
tape->last_stage = stage;
if (tape->next_stage == NULL)
tape->next_stage = tape->last_stage;
tape->nr_stages++;
tape->nr_pending_stages++;
spin_unlock_irqrestore(&tape->spinlock, flags);
}
/*
* idetape_wait_for_request installs a completion in a pending request
* and sleeps until it is serviced.
*
* The caller should ensure that the request will not be serviced
* before we install the completion (usually by disabling interrupts).
*/
static void idetape_wait_for_request (ide_drive_t *drive, struct request *rq)
{
DECLARE_COMPLETION_ONSTACK(wait);
idetape_tape_t *tape = drive->driver_data;
if (rq == NULL || !blk_special_request(rq)) {
printk (KERN_ERR "ide-tape: bug: Trying to sleep on non-valid request\n");
return;
}
rq->end_io_data = &wait;
rq->end_io = blk_end_sync_rq;
spin_unlock_irq(&tape->spinlock);
wait_for_completion(&wait);
/* The stage and its struct request have been deallocated */
spin_lock_irq(&tape->spinlock);
}
static ide_startstop_t idetape_read_position_callback(ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
u8 *readpos = tape->pc->buffer;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
if (!tape->pc->error) {
debug_log(DBG_SENSE, "BOP - %s\n",
(readpos[0] & 0x80) ? "Yes" : "No");
debug_log(DBG_SENSE, "EOP - %s\n",
(readpos[0] & 0x40) ? "Yes" : "No");
if (readpos[0] & 0x4) {
printk(KERN_INFO "ide-tape: Block location is unknown"
"to the tape\n");
clear_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
idetape_end_request(drive, 0, 0);
} else {
debug_log(DBG_SENSE, "Block Location - %u\n",
be32_to_cpu(*(u32 *)&readpos[4]));
tape->partition = readpos[1];
tape->first_frame_position =
be32_to_cpu(*(u32 *)&readpos[4]);
set_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
idetape_end_request(drive, 1, 0);
}
} else {
idetape_end_request(drive, 0, 0);
}
return ide_stopped;
}
/*
* idetape_create_write_filemark_cmd will:
*
* 1. Write a filemark if write_filemark=1.
* 2. Flush the device buffers without writing a filemark
* if write_filemark=0.
*
*/
static void idetape_create_write_filemark_cmd (ide_drive_t *drive, idetape_pc_t *pc,int write_filemark)
{
idetape_init_pc(pc);
pc->c[0] = WRITE_FILEMARKS;
pc->c[4] = write_filemark;
set_bit(PC_WAIT_FOR_DSC, &pc->flags);
pc->callback = &idetape_pc_callback;
}
static void idetape_create_test_unit_ready_cmd(idetape_pc_t *pc)
{
idetape_init_pc(pc);
pc->c[0] = TEST_UNIT_READY;
pc->callback = &idetape_pc_callback;
}
/*
* idetape_queue_pc_tail is based on the following functions:
*
* ide_do_drive_cmd from ide.c
* cdrom_queue_request and cdrom_queue_packet_command from ide-cd.c
*
* We add a special packet command request to the tail of the request
* queue, and wait for it to be serviced.
*
* This is not to be called from within the request handling part
* of the driver ! We allocate here data in the stack, and it is valid
* until the request is finished. This is not the case for the bottom
* part of the driver, where we are always leaving the functions to wait
* for an interrupt or a timer event.
*
* From the bottom part of the driver, we should allocate safe memory
* using idetape_next_pc_storage and idetape_next_rq_storage, and add
* the request to the request list without waiting for it to be serviced !
* In that case, we usually use idetape_queue_pc_head.
*/
static int __idetape_queue_pc_tail (ide_drive_t *drive, idetape_pc_t *pc)
{
struct ide_tape_obj *tape = drive->driver_data;
struct request rq;
idetape_init_rq(&rq, REQ_IDETAPE_PC1);
rq.buffer = (char *) pc;
rq.rq_disk = tape->disk;
return ide_do_drive_cmd(drive, &rq, ide_wait);
}
static void idetape_create_load_unload_cmd (ide_drive_t *drive, idetape_pc_t *pc,int cmd)
{
idetape_init_pc(pc);
pc->c[0] = START_STOP;
pc->c[4] = cmd;
set_bit(PC_WAIT_FOR_DSC, &pc->flags);
pc->callback = &idetape_pc_callback;
}
static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t pc;
int load_attempted = 0;
/*
* Wait for the tape to become ready
*/
set_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
timeout += jiffies;
while (time_before(jiffies, timeout)) {
idetape_create_test_unit_ready_cmd(&pc);
if (!__idetape_queue_pc_tail(drive, &pc))
return 0;
if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
|| (tape->asc == 0x3A)) { /* no media */
if (load_attempted)
return -ENOMEDIUM;
idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
__idetape_queue_pc_tail(drive, &pc);
load_attempted = 1;
/* not about to be ready */
} else if (!(tape->sense_key == 2 && tape->asc == 4 &&
(tape->ascq == 1 || tape->ascq == 8)))
return -EIO;
msleep(100);
}
return -EIO;
}
static int idetape_queue_pc_tail (ide_drive_t *drive,idetape_pc_t *pc)
{
return __idetape_queue_pc_tail(drive, pc);
}
static int idetape_flush_tape_buffers (ide_drive_t *drive)
{
idetape_pc_t pc;
int rc;
idetape_create_write_filemark_cmd(drive, &pc, 0);
if ((rc = idetape_queue_pc_tail(drive, &pc)))
return rc;
idetape_wait_ready(drive, 60 * 5 * HZ);
return 0;
}
static void idetape_create_read_position_cmd (idetape_pc_t *pc)
{
idetape_init_pc(pc);
pc->c[0] = READ_POSITION;
pc->request_transfer = 20;
pc->callback = &idetape_read_position_callback;
}
static int idetape_read_position (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t pc;
int position;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
idetape_create_read_position_cmd(&pc);
if (idetape_queue_pc_tail(drive, &pc))
return -1;
position = tape->first_frame_position;
return position;
}
static void idetape_create_locate_cmd (ide_drive_t *drive, idetape_pc_t *pc, unsigned int block, u8 partition, int skip)
{
idetape_init_pc(pc);
pc->c[0] = POSITION_TO_ELEMENT;
pc->c[1] = 2;
put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
pc->c[8] = partition;
set_bit(PC_WAIT_FOR_DSC, &pc->flags);
pc->callback = &idetape_pc_callback;
}
static int idetape_create_prevent_cmd (ide_drive_t *drive, idetape_pc_t *pc, int prevent)
{
idetape_tape_t *tape = drive->driver_data;
/* device supports locking according to capabilities page */
if (!(tape->caps[6] & 0x01))
return 0;
idetape_init_pc(pc);
pc->c[0] = ALLOW_MEDIUM_REMOVAL;
pc->c[4] = prevent;
pc->callback = &idetape_pc_callback;
return 1;
}
static int __idetape_discard_read_pipeline (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
unsigned long flags;
int cnt;
if (tape->chrdev_dir != IDETAPE_DIR_READ)
return 0;
/* Remove merge stage. */
cnt = tape->merge_stage_size / tape->tape_block_size;
if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
++cnt; /* Filemarks count as 1 sector */
tape->merge_stage_size = 0;
if (tape->merge_stage != NULL) {
__idetape_kfree_stage(tape->merge_stage);
tape->merge_stage = NULL;
}
/* Clear pipeline flags. */
clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
tape->chrdev_dir = IDETAPE_DIR_NONE;
/* Remove pipeline stages. */
if (tape->first_stage == NULL)
return 0;
spin_lock_irqsave(&tape->spinlock, flags);
tape->next_stage = NULL;
if (idetape_pipeline_active(tape))
idetape_wait_for_request(drive, tape->active_data_request);
spin_unlock_irqrestore(&tape->spinlock, flags);
while (tape->first_stage != NULL) {
struct request *rq_ptr = &tape->first_stage->rq;
cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors;
if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
++cnt;
idetape_remove_stage_head(drive);
}
tape->nr_pending_stages = 0;
tape->max_stages = tape->min_pipeline;
return cnt;
}
/*
* idetape_position_tape positions the tape to the requested block
* using the LOCATE packet command. A READ POSITION command is then
* issued to check where we are positioned.
*
* Like all higher level operations, we queue the commands at the tail
* of the request queue and wait for their completion.
*
*/
static int idetape_position_tape (ide_drive_t *drive, unsigned int block, u8 partition, int skip)
{
idetape_tape_t *tape = drive->driver_data;
int retval;
idetape_pc_t pc;
if (tape->chrdev_dir == IDETAPE_DIR_READ)
__idetape_discard_read_pipeline(drive);
idetape_wait_ready(drive, 60 * 5 * HZ);
idetape_create_locate_cmd(drive, &pc, block, partition, skip);
retval = idetape_queue_pc_tail(drive, &pc);
if (retval)
return (retval);
idetape_create_read_position_cmd(&pc);
return (idetape_queue_pc_tail(drive, &pc));
}
static void idetape_discard_read_pipeline (ide_drive_t *drive, int restore_position)
{
idetape_tape_t *tape = drive->driver_data;
int cnt;
int seek, position;
cnt = __idetape_discard_read_pipeline(drive);
if (restore_position) {
position = idetape_read_position(drive);
seek = position > cnt ? position - cnt : 0;
if (idetape_position_tape(drive, seek, 0, 0)) {
printk(KERN_INFO "ide-tape: %s: position_tape failed in discard_pipeline()\n", tape->name);
return;
}
}
}
/*
* idetape_queue_rw_tail generates a read/write request for the block
* device interface and wait for it to be serviced.
*/
static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, struct idetape_bh *bh)
{
idetape_tape_t *tape = drive->driver_data;
struct request rq;
debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
if (idetape_pipeline_active(tape)) {
printk(KERN_ERR "ide-tape: bug: the pipeline is active in %s\n",
__func__);
return (0);
}
idetape_init_rq(&rq, cmd);
rq.rq_disk = tape->disk;
rq.special = (void *)bh;
rq.sector = tape->first_frame_position;
rq.nr_sectors = rq.current_nr_sectors = blocks;
(void) ide_do_drive_cmd(drive, &rq, ide_wait);
if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0)
return 0;
if (tape->merge_stage)
idetape_init_merge_stage(tape);
if (rq.errors == IDETAPE_ERROR_GENERAL)
return -EIO;
return (tape->tape_block_size * (blocks-rq.current_nr_sectors));
}
/*
* idetape_insert_pipeline_into_queue is used to start servicing the
* pipeline stages, starting from tape->next_stage.
*/
static void idetape_insert_pipeline_into_queue (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
if (tape->next_stage == NULL)
return;
if (!idetape_pipeline_active(tape)) {
set_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
idetape_activate_next_stage(drive);
(void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end);
}
}
static void idetape_create_inquiry_cmd (idetape_pc_t *pc)
{
idetape_init_pc(pc);
pc->c[0] = INQUIRY;
pc->c[4] = pc->request_transfer = 254;
pc->callback = &idetape_pc_callback;
}
static void idetape_create_rewind_cmd (ide_drive_t *drive, idetape_pc_t *pc)
{
idetape_init_pc(pc);
pc->c[0] = REZERO_UNIT;
set_bit(PC_WAIT_FOR_DSC, &pc->flags);
pc->callback = &idetape_pc_callback;
}
static void idetape_create_erase_cmd (idetape_pc_t *pc)
{
idetape_init_pc(pc);
pc->c[0] = ERASE;
pc->c[1] = 1;
set_bit(PC_WAIT_FOR_DSC, &pc->flags);
pc->callback = &idetape_pc_callback;
}
static void idetape_create_space_cmd (idetape_pc_t *pc,int count, u8 cmd)
{
idetape_init_pc(pc);
pc->c[0] = SPACE;
put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
pc->c[1] = cmd;
set_bit(PC_WAIT_FOR_DSC, &pc->flags);
pc->callback = &idetape_pc_callback;
}
static void idetape_wait_first_stage (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
unsigned long flags;
if (tape->first_stage == NULL)
return;
spin_lock_irqsave(&tape->spinlock, flags);
if (tape->active_stage == tape->first_stage)
idetape_wait_for_request(drive, tape->active_data_request);
spin_unlock_irqrestore(&tape->spinlock, flags);
}
/*
* idetape_add_chrdev_write_request tries to add a character device
* originated write request to our pipeline. In case we don't succeed,
* we revert to non-pipelined operation mode for this request.
*
* 1. Try to allocate a new pipeline stage.
* 2. If we can't, wait for more and more requests to be serviced
* and try again each time.
* 3. If we still can't allocate a stage, fallback to
* non-pipelined operation mode for this request.
*/
static int idetape_add_chrdev_write_request (ide_drive_t *drive, int blocks)
{
idetape_tape_t *tape = drive->driver_data;
idetape_stage_t *new_stage;
unsigned long flags;
struct request *rq;
debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
/*
* Attempt to allocate a new stage.
* Pay special attention to possible race conditions.
*/
while ((new_stage = idetape_kmalloc_stage(tape)) == NULL) {
spin_lock_irqsave(&tape->spinlock, flags);
if (idetape_pipeline_active(tape)) {
idetape_wait_for_request(drive, tape->active_data_request);
spin_unlock_irqrestore(&tape->spinlock, flags);
} else {
spin_unlock_irqrestore(&tape->spinlock, flags);
idetape_insert_pipeline_into_queue(drive);
if (idetape_pipeline_active(tape))
continue;
/*
* Linux is short on memory. Fallback to
* non-pipelined operation mode for this request.
*/
return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
}
}
rq = &new_stage->rq;
idetape_init_rq(rq, REQ_IDETAPE_WRITE);
/* Doesn't actually matter - We always assume sequential access */
rq->sector = tape->first_frame_position;
rq->nr_sectors = rq->current_nr_sectors = blocks;
idetape_switch_buffers(tape, new_stage);
idetape_add_stage_tail(drive, new_stage);
tape->pipeline_head++;
idetape_calculate_speeds(drive);
/*
* Estimate whether the tape has stopped writing by checking
* if our write pipeline is currently empty. If we are not
* writing anymore, wait for the pipeline to be full enough
* (90%) before starting to service requests, so that we will
* be able to keep up with the higher speeds of the tape.
*/
if (!idetape_pipeline_active(tape)) {
if (tape->nr_stages >= tape->max_stages * 9 / 10 ||
tape->nr_stages >= tape->max_stages - tape->uncontrolled_pipeline_head_speed * 3 * 1024 / tape->tape_block_size) {
tape->measure_insert_time = 1;
tape->insert_time = jiffies;
tape->insert_size = 0;
tape->insert_speed = 0;
idetape_insert_pipeline_into_queue(drive);
}
}
if (test_and_clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
/* Return a deferred error */
return -EIO;
return blocks;
}
/*
* idetape_wait_for_pipeline will wait until all pending pipeline
* requests are serviced. Typically called on device close.
*/
static void idetape_wait_for_pipeline (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
unsigned long flags;
while (tape->next_stage || idetape_pipeline_active(tape)) {
idetape_insert_pipeline_into_queue(drive);
spin_lock_irqsave(&tape->spinlock, flags);
if (idetape_pipeline_active(tape))
idetape_wait_for_request(drive, tape->active_data_request);
spin_unlock_irqrestore(&tape->spinlock, flags);
}
}
static void idetape_empty_write_pipeline (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
int blocks, min;
struct idetape_bh *bh;
if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline, but we are not writing.\n");
return;
}
if (tape->merge_stage_size > tape->stage_size) {
printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n");
tape->merge_stage_size = tape->stage_size;
}
if (tape->merge_stage_size) {
blocks = tape->merge_stage_size / tape->tape_block_size;
if (tape->merge_stage_size % tape->tape_block_size) {
unsigned int i;
blocks++;
i = tape->tape_block_size - tape->merge_stage_size % tape->tape_block_size;
bh = tape->bh->b_reqnext;
while (bh) {
atomic_set(&bh->b_count, 0);
bh = bh->b_reqnext;
}
bh = tape->bh;
while (i) {
if (bh == NULL) {
printk(KERN_INFO "ide-tape: bug, bh NULL\n");
break;
}
min = min(i, (unsigned int)(bh->b_size - atomic_read(&bh->b_count)));
memset(bh->b_data + atomic_read(&bh->b_count), 0, min);
atomic_add(min, &bh->b_count);
i -= min;
bh = bh->b_reqnext;
}
}
(void) idetape_add_chrdev_write_request(drive, blocks);
tape->merge_stage_size = 0;
}
idetape_wait_for_pipeline(drive);
if (tape->merge_stage != NULL) {
__idetape_kfree_stage(tape->merge_stage);
tape->merge_stage = NULL;
}
clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
tape->chrdev_dir = IDETAPE_DIR_NONE;
/*
* On the next backup, perform the feedback loop again.
* (I don't want to keep sense information between backups,
* as some systems are constantly on, and the system load
* can be totally different on the next backup).
*/
tape->max_stages = tape->min_pipeline;
if (tape->first_stage != NULL ||
tape->next_stage != NULL ||
tape->last_stage != NULL ||
tape->nr_stages != 0) {
printk(KERN_ERR "ide-tape: ide-tape pipeline bug, "
"first_stage %p, next_stage %p, "
"last_stage %p, nr_stages %d\n",
tape->first_stage, tape->next_stage,
tape->last_stage, tape->nr_stages);
}
}
static void idetape_restart_speed_control (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
tape->restart_speed_control_req = 0;
tape->pipeline_head = 0;
tape->controlled_last_pipeline_head = 0;
tape->controlled_previous_pipeline_head = tape->uncontrolled_previous_pipeline_head = 0;
tape->pipeline_head_speed = tape->controlled_pipeline_head_speed = 5000;
tape->uncontrolled_pipeline_head_speed = 0;
tape->controlled_pipeline_head_time = tape->uncontrolled_pipeline_head_time = jiffies;
tape->controlled_previous_head_time = tape->uncontrolled_previous_head_time = jiffies;
}
static int idetape_initiate_read (ide_drive_t *drive, int max_stages)
{
idetape_tape_t *tape = drive->driver_data;
idetape_stage_t *new_stage;
struct request rq;
int bytes_read;
u16 blocks = *(u16 *)&tape->caps[12];
/* Initialize read operation */
if (tape->chrdev_dir != IDETAPE_DIR_READ) {
if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
idetape_empty_write_pipeline(drive);
idetape_flush_tape_buffers(drive);
}
if (tape->merge_stage || tape->merge_stage_size) {
printk (KERN_ERR "ide-tape: merge_stage_size should be 0 now\n");
tape->merge_stage_size = 0;
}
if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
return -ENOMEM;
tape->chrdev_dir = IDETAPE_DIR_READ;
/*
* Issue a read 0 command to ensure that DSC handshake
* is switched from completion mode to buffer available
* mode.
* No point in issuing this if DSC overlap isn't supported,
* some drives (Seagate STT3401A) will return an error.
*/
if (drive->dsc_overlap) {
bytes_read = idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, 0, tape->merge_stage->bh);
if (bytes_read < 0) {
__idetape_kfree_stage(tape->merge_stage);
tape->merge_stage = NULL;
tape->chrdev_dir = IDETAPE_DIR_NONE;
return bytes_read;
}
}
}
if (tape->restart_speed_control_req)
idetape_restart_speed_control(drive);
idetape_init_rq(&rq, REQ_IDETAPE_READ);
rq.sector = tape->first_frame_position;
rq.nr_sectors = rq.current_nr_sectors = blocks;
if (!test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags) &&
tape->nr_stages < max_stages) {
new_stage = idetape_kmalloc_stage(tape);
while (new_stage != NULL) {
new_stage->rq = rq;
idetape_add_stage_tail(drive, new_stage);
if (tape->nr_stages >= max_stages)
break;
new_stage = idetape_kmalloc_stage(tape);
}
}
if (!idetape_pipeline_active(tape)) {
if (tape->nr_pending_stages >= 3 * max_stages / 4) {
tape->measure_insert_time = 1;
tape->insert_time = jiffies;
tape->insert_size = 0;
tape->insert_speed = 0;
idetape_insert_pipeline_into_queue(drive);
}
}
return 0;
}
/*
* idetape_add_chrdev_read_request is called from idetape_chrdev_read
* to service a character device read request and add read-ahead
* requests to our pipeline.
*/
static int idetape_add_chrdev_read_request (ide_drive_t *drive,int blocks)
{
idetape_tape_t *tape = drive->driver_data;
unsigned long flags;
struct request *rq_ptr;
int bytes_read;
debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks);
/*
* If we are at a filemark, return a read length of 0
*/
if (test_bit(IDETAPE_FILEMARK, &tape->flags))
return 0;
/*
* Wait for the next block to be available at the head
* of the pipeline
*/
idetape_initiate_read(drive, tape->max_stages);
if (tape->first_stage == NULL) {
if (test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
return 0;
return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks, tape->merge_stage->bh);
}
idetape_wait_first_stage(drive);
rq_ptr = &tape->first_stage->rq;
bytes_read = tape->tape_block_size * (rq_ptr->nr_sectors - rq_ptr->current_nr_sectors);
rq_ptr->nr_sectors = rq_ptr->current_nr_sectors = 0;
if (rq_ptr->errors == IDETAPE_ERROR_EOD)
return 0;
else {
idetape_switch_buffers(tape, tape->first_stage);
if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
set_bit(IDETAPE_FILEMARK, &tape->flags);
spin_lock_irqsave(&tape->spinlock, flags);
idetape_remove_stage_head(drive);
spin_unlock_irqrestore(&tape->spinlock, flags);
tape->pipeline_head++;
idetape_calculate_speeds(drive);
}
if (bytes_read > blocks * tape->tape_block_size) {
printk(KERN_ERR "ide-tape: bug: trying to return more bytes than requested\n");
bytes_read = blocks * tape->tape_block_size;
}
return (bytes_read);
}
static void idetape_pad_zeros (ide_drive_t *drive, int bcount)
{
idetape_tape_t *tape = drive->driver_data;
struct idetape_bh *bh;
int blocks;
while (bcount) {
unsigned int count;
bh = tape->merge_stage->bh;
count = min(tape->stage_size, bcount);
bcount -= count;
blocks = count / tape->tape_block_size;
while (count) {
atomic_set(&bh->b_count, min(count, (unsigned int)bh->b_size));
memset(bh->b_data, 0, atomic_read(&bh->b_count));
count -= atomic_read(&bh->b_count);
bh = bh->b_reqnext;
}
idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
}
}
static int idetape_pipeline_size (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_stage_t *stage;
struct request *rq;
int size = 0;
idetape_wait_for_pipeline(drive);
stage = tape->first_stage;
while (stage != NULL) {
rq = &stage->rq;
size += tape->tape_block_size * (rq->nr_sectors-rq->current_nr_sectors);
if (rq->errors == IDETAPE_ERROR_FILEMARK)
size += tape->tape_block_size;
stage = stage->next;
}
size += tape->merge_stage_size;
return size;
}
/*
* Rewinds the tape to the Beginning Of the current Partition (BOP).
*
* We currently support only one partition.
*/
static int idetape_rewind_tape (ide_drive_t *drive)
{
int retval;
idetape_pc_t pc;
idetape_tape_t *tape;
tape = drive->driver_data;
debug_log(DBG_SENSE, "Enter %s\n", __func__);
idetape_create_rewind_cmd(drive, &pc);
retval = idetape_queue_pc_tail(drive, &pc);
if (retval)
return retval;
idetape_create_read_position_cmd(&pc);
retval = idetape_queue_pc_tail(drive, &pc);
if (retval)
return retval;
return 0;
}
/*
* Our special ide-tape ioctl's.
*
* Currently there aren't any ioctl's.
* mtio.h compatible commands should be issued to the character device
* interface.
*/
static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd, unsigned long arg)
{
idetape_tape_t *tape = drive->driver_data;
void __user *argp = (void __user *)arg;
struct idetape_config {
int dsc_rw_frequency;
int dsc_media_access_frequency;
int nr_stages;
} config;
debug_log(DBG_PROCS, "Enter %s\n", __func__);
switch (cmd) {
case 0x0340:
if (copy_from_user(&config, argp, sizeof(config)))
return -EFAULT;
tape->best_dsc_rw_frequency = config.dsc_rw_frequency;
tape->max_stages = config.nr_stages;
break;
case 0x0350:
config.dsc_rw_frequency = (int) tape->best_dsc_rw_frequency;
config.nr_stages = tape->max_stages;
if (copy_to_user(argp, &config, sizeof(config)))
return -EFAULT;
break;
default:
return -EIO;
}
return 0;
}
/*
* idetape_space_over_filemarks is now a bit more complicated than just
* passing the command to the tape since we may have crossed some
* filemarks during our pipelined read-ahead mode.
*
* As a minor side effect, the pipeline enables us to support MTFSFM when
* the filemark is in our internal pipeline even if the tape doesn't
* support spacing over filemarks in the reverse direction.
*/
static int idetape_space_over_filemarks (ide_drive_t *drive,short mt_op,int mt_count)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t pc;
unsigned long flags;
int retval,count=0;
int sprev = !!(tape->caps[4] & 0x20);
if (mt_count == 0)
return 0;
if (MTBSF == mt_op || MTBSFM == mt_op) {
if (!sprev)
return -EIO;
mt_count = - mt_count;
}
if (tape->chrdev_dir == IDETAPE_DIR_READ) {
/*
* We have a read-ahead buffer. Scan it for crossed
* filemarks.
*/
tape->merge_stage_size = 0;
if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
++count;
while (tape->first_stage != NULL) {
if (count == mt_count) {
if (mt_op == MTFSFM)
set_bit(IDETAPE_FILEMARK, &tape->flags);
return 0;
}
spin_lock_irqsave(&tape->spinlock, flags);
if (tape->first_stage == tape->active_stage) {
/*
* We have reached the active stage in the read pipeline.
* There is no point in allowing the drive to continue
* reading any farther, so we stop the pipeline.
*
* This section should be moved to a separate subroutine,
* because a similar function is performed in
* __idetape_discard_read_pipeline(), for example.
*/
tape->next_stage = NULL;
spin_unlock_irqrestore(&tape->spinlock, flags);
idetape_wait_first_stage(drive);
tape->next_stage = tape->first_stage->next;
} else
spin_unlock_irqrestore(&tape->spinlock, flags);
if (tape->first_stage->rq.errors == IDETAPE_ERROR_FILEMARK)
++count;
idetape_remove_stage_head(drive);
}
idetape_discard_read_pipeline(drive, 0);
}
/*
* The filemark was not found in our internal pipeline.
* Now we can issue the space command.
*/
switch (mt_op) {
case MTFSF:
case MTBSF:
idetape_create_space_cmd(&pc,mt_count-count,IDETAPE_SPACE_OVER_FILEMARK);
return (idetape_queue_pc_tail(drive, &pc));
case MTFSFM:
case MTBSFM:
if (!sprev)
return (-EIO);
retval = idetape_space_over_filemarks(drive, MTFSF, mt_count-count);
if (retval) return (retval);
count = (MTBSFM == mt_op ? 1 : -1);
return (idetape_space_over_filemarks(drive, MTFSF, count));
default:
printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",mt_op);
return (-EIO);
}
}
/*
* Our character device read / write functions.
*
* The tape is optimized to maximize throughput when it is transferring
* an integral number of the "continuous transfer limit", which is
* a parameter of the specific tape (26 KB on my particular tape).
* (32 kB for Onstream)
*
* As of version 1.3 of the driver, the character device provides an
* abstract continuous view of the media - any mix of block sizes (even 1
* byte) on the same backup/restore procedure is supported. The driver
* will internally convert the requests to the recommended transfer unit,
* so that an unmatch between the user's block size to the recommended
* size will only result in a (slightly) increased driver overhead, but
* will no longer hit performance.
* This is not applicable to Onstream.
*/
static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct ide_tape_obj *tape = ide_tape_f(file);
ide_drive_t *drive = tape->drive;
ssize_t bytes_read,temp, actually_read = 0, rc;
ssize_t ret = 0;
u16 ctl = *(u16 *)&tape->caps[12];
debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
if (tape->chrdev_dir != IDETAPE_DIR_READ) {
if (test_bit(IDETAPE_DETECT_BS, &tape->flags))
if (count > tape->tape_block_size &&
(count % tape->tape_block_size) == 0)
tape->user_bs_factor = count / tape->tape_block_size;
}
if ((rc = idetape_initiate_read(drive, tape->max_stages)) < 0)
return rc;
if (count == 0)
return (0);
if (tape->merge_stage_size) {
actually_read = min((unsigned int)(tape->merge_stage_size), (unsigned int)count);
if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read))
ret = -EFAULT;
buf += actually_read;
tape->merge_stage_size -= actually_read;
count -= actually_read;
}
while (count >= tape->stage_size) {
bytes_read = idetape_add_chrdev_read_request(drive, ctl);
if (bytes_read <= 0)
goto finish;
if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read))
ret = -EFAULT;
buf += bytes_read;
count -= bytes_read;
actually_read += bytes_read;
}
if (count) {
bytes_read = idetape_add_chrdev_read_request(drive, ctl);
if (bytes_read <= 0)
goto finish;
temp = min((unsigned long)count, (unsigned long)bytes_read);
if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp))
ret = -EFAULT;
actually_read += temp;
tape->merge_stage_size = bytes_read-temp;
}
finish:
if (!actually_read && test_bit(IDETAPE_FILEMARK, &tape->flags)) {
debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
idetape_space_over_filemarks(drive, MTFSF, 1);
return 0;
}
return (ret) ? ret : actually_read;
}
static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct ide_tape_obj *tape = ide_tape_f(file);
ide_drive_t *drive = tape->drive;
ssize_t actually_written = 0;
ssize_t ret = 0;
u16 ctl = *(u16 *)&tape->caps[12];
/* The drive is write protected. */
if (tape->write_prot)
return -EACCES;
debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
/* Initialize write operation */
if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
if (tape->chrdev_dir == IDETAPE_DIR_READ)
idetape_discard_read_pipeline(drive, 1);
if (tape->merge_stage || tape->merge_stage_size) {
printk(KERN_ERR "ide-tape: merge_stage_size "
"should be 0 now\n");
tape->merge_stage_size = 0;
}
if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
return -ENOMEM;
tape->chrdev_dir = IDETAPE_DIR_WRITE;
idetape_init_merge_stage(tape);
/*
* Issue a write 0 command to ensure that DSC handshake
* is switched from completion mode to buffer available
* mode.
* No point in issuing this if DSC overlap isn't supported,
* some drives (Seagate STT3401A) will return an error.
*/
if (drive->dsc_overlap) {
ssize_t retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);
if (retval < 0) {
__idetape_kfree_stage(tape->merge_stage);
tape->merge_stage = NULL;
tape->chrdev_dir = IDETAPE_DIR_NONE;
return retval;
}
}
}
if (count == 0)
return (0);
if (tape->restart_speed_control_req)
idetape_restart_speed_control(drive);
if (tape->merge_stage_size) {
if (tape->merge_stage_size >= tape->stage_size) {
printk(KERN_ERR "ide-tape: bug: merge buffer too big\n");
tape->merge_stage_size = 0;
}
actually_written = min((unsigned int)(tape->stage_size - tape->merge_stage_size), (unsigned int)count);
if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written))
ret = -EFAULT;
buf += actually_written;
tape->merge_stage_size += actually_written;
count -= actually_written;
if (tape->merge_stage_size == tape->stage_size) {
ssize_t retval;
tape->merge_stage_size = 0;
retval = idetape_add_chrdev_write_request(drive, ctl);
if (retval <= 0)
return (retval);
}
}
while (count >= tape->stage_size) {
ssize_t retval;
if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size))
ret = -EFAULT;
buf += tape->stage_size;
count -= tape->stage_size;
retval = idetape_add_chrdev_write_request(drive, ctl);
actually_written += tape->stage_size;
if (retval <= 0)
return (retval);
}
if (count) {
actually_written += count;
if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count))
ret = -EFAULT;
tape->merge_stage_size += count;
}
return (ret) ? ret : actually_written;
}
static int idetape_write_filemark (ide_drive_t *drive)
{
idetape_pc_t pc;
/* Write a filemark */
idetape_create_write_filemark_cmd(drive, &pc, 1);
if (idetape_queue_pc_tail(drive, &pc)) {
printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
return -EIO;
}
return 0;
}
/*
* Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
* requested.
*
* Note: MTBSF and MTBSFM are not supported when the tape doesn't support
* spacing over filemarks in the reverse direction. In this case, MTFSFM is also
* usually not supported (it is supported in the rare case in which we crossed
* the filemark during our read-ahead pipelined operation mode).
*
* The following commands are currently not supported:
*
* MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
* MT_ST_WRITE_THRESHOLD.
*/
static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t pc;
int i,retval;
debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
mt_op, mt_count);
/*
* Commands which need our pipelined read-ahead stages.
*/
switch (mt_op) {
case MTFSF:
case MTFSFM:
case MTBSF:
case MTBSFM:
if (!mt_count)
return (0);
return (idetape_space_over_filemarks(drive,mt_op,mt_count));
default:
break;
}
switch (mt_op) {
case MTWEOF:
if (tape->write_prot)
return -EACCES;
idetape_discard_read_pipeline(drive, 1);
for (i = 0; i < mt_count; i++) {
retval = idetape_write_filemark(drive);
if (retval)
return retval;
}
return (0);
case MTREW:
idetape_discard_read_pipeline(drive, 0);
if (idetape_rewind_tape(drive))
return -EIO;
return 0;
case MTLOAD:
idetape_discard_read_pipeline(drive, 0);
idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
return (idetape_queue_pc_tail(drive, &pc));
case MTUNLOAD:
case MTOFFL:
/*
* If door is locked, attempt to unlock before
* attempting to eject.
*/
if (tape->door_locked) {
if (idetape_create_prevent_cmd(drive, &pc, 0))
if (!idetape_queue_pc_tail(drive, &pc))
tape->door_locked = DOOR_UNLOCKED;
}
idetape_discard_read_pipeline(drive, 0);
idetape_create_load_unload_cmd(drive, &pc,!IDETAPE_LU_LOAD_MASK);
retval = idetape_queue_pc_tail(drive, &pc);
if (!retval)
clear_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
return retval;
case MTNOP:
idetape_discard_read_pipeline(drive, 0);
return (idetape_flush_tape_buffers(drive));
case MTRETEN:
idetape_discard_read_pipeline(drive, 0);
idetape_create_load_unload_cmd(drive, &pc,IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
return (idetape_queue_pc_tail(drive, &pc));
case MTEOM:
idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
return (idetape_queue_pc_tail(drive, &pc));
case MTERASE:
(void) idetape_rewind_tape(drive);
idetape_create_erase_cmd(&pc);
return (idetape_queue_pc_tail(drive, &pc));
case MTSETBLK:
if (mt_count) {
if (mt_count < tape->tape_block_size || mt_count % tape->tape_block_size)
return -EIO;
tape->user_bs_factor = mt_count / tape->tape_block_size;
clear_bit(IDETAPE_DETECT_BS, &tape->flags);
} else
set_bit(IDETAPE_DETECT_BS, &tape->flags);
return 0;
case MTSEEK:
idetape_discard_read_pipeline(drive, 0);
return idetape_position_tape(drive, mt_count * tape->user_bs_factor, tape->partition, 0);
case MTSETPART:
idetape_discard_read_pipeline(drive, 0);
return (idetape_position_tape(drive, 0, mt_count, 0));
case MTFSR:
case MTBSR:
case MTLOCK:
if (!idetape_create_prevent_cmd(drive, &pc, 1))
return 0;
retval = idetape_queue_pc_tail(drive, &pc);
if (retval) return retval;
tape->door_locked = DOOR_EXPLICITLY_LOCKED;
return 0;
case MTUNLOCK:
if (!idetape_create_prevent_cmd(drive, &pc, 0))
return 0;
retval = idetape_queue_pc_tail(drive, &pc);
if (retval) return retval;
tape->door_locked = DOOR_UNLOCKED;
return 0;
default:
printk(KERN_ERR "ide-tape: MTIO operation %d not "
"supported\n", mt_op);
return (-EIO);
}
}
/*
* Our character device ioctls. General mtio.h magnetic io commands are
* supported here, and not in the corresponding block interface. Our own
* ide-tape ioctls are supported on both interfaces.
*/
static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct ide_tape_obj *tape = ide_tape_f(file);
ide_drive_t *drive = tape->drive;
struct mtop mtop;
struct mtget mtget;
struct mtpos mtpos;
int block_offset = 0, position = tape->first_frame_position;
void __user *argp = (void __user *)arg;
debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
tape->restart_speed_control_req = 1;
if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
idetape_empty_write_pipeline(drive);
idetape_flush_tape_buffers(drive);
}
if (cmd == MTIOCGET || cmd == MTIOCPOS) {
block_offset = idetape_pipeline_size(drive) / (tape->tape_block_size * tape->user_bs_factor);
if ((position = idetape_read_position(drive)) < 0)
return -EIO;
}
switch (cmd) {
case MTIOCTOP:
if (copy_from_user(&mtop, argp, sizeof (struct mtop)))
return -EFAULT;
return (idetape_mtioctop(drive,mtop.mt_op,mtop.mt_count));
case MTIOCGET:
memset(&mtget, 0, sizeof (struct mtget));
mtget.mt_type = MT_ISSCSI2;
mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
mtget.mt_dsreg = ((tape->tape_block_size * tape->user_bs_factor) << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
if (tape->drv_write_prot) {
mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
}
if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
return -EFAULT;
return 0;
case MTIOCPOS:
mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
return -EFAULT;
return 0;
default:
if (tape->chrdev_dir == IDETAPE_DIR_READ)
idetape_discard_read_pipeline(drive, 1);
return idetape_blkdev_ioctl(drive, cmd, arg);
}
}
/*
* Do a mode sense page 0 with block descriptor and if it succeeds set the tape
* block size with the reported value.
*/
static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t pc;
idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
if (idetape_queue_pc_tail(drive, &pc)) {
printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
if (tape->tape_block_size == 0) {
printk(KERN_WARNING "ide-tape: Cannot deal with zero "
"block size, assuming 32k\n");
tape->tape_block_size = 32768;
}
return;
}
tape->tape_block_size = (pc.buffer[4 + 5] << 16) +
(pc.buffer[4 + 6] << 8) +
pc.buffer[4 + 7];
tape->drv_write_prot = (pc.buffer[2] & 0x80) >> 7;
}
/*
* Our character device open function.
*/
static int idetape_chrdev_open (struct inode *inode, struct file *filp)
{
unsigned int minor = iminor(inode), i = minor & ~0xc0;
ide_drive_t *drive;
idetape_tape_t *tape;
idetape_pc_t pc;
int retval;
if (i >= MAX_HWIFS * MAX_DRIVES)
return -ENXIO;
tape = ide_tape_chrdev_get(i);
if (!tape)
return -ENXIO;
debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
/*
* We really want to do nonseekable_open(inode, filp); here, but some
* versions of tar incorrectly call lseek on tapes and bail out if that
* fails. So we disallow pread() and pwrite(), but permit lseeks.
*/
filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
drive = tape->drive;
filp->private_data = tape;
if (test_and_set_bit(IDETAPE_BUSY, &tape->flags)) {
retval = -EBUSY;
goto out_put_tape;
}
retval = idetape_wait_ready(drive, 60 * HZ);
if (retval) {
clear_bit(IDETAPE_BUSY, &tape->flags);
printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
goto out_put_tape;
}
idetape_read_position(drive);
if (!test_bit(IDETAPE_ADDRESS_VALID, &tape->flags))
(void)idetape_rewind_tape(drive);
if (tape->chrdev_dir != IDETAPE_DIR_READ)
clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
/* Read block size and write protect status from drive. */
ide_tape_get_bsize_from_bdesc(drive);
/* Set write protect flag if device is opened as read-only. */
if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
tape->write_prot = 1;
else
tape->write_prot = tape->drv_write_prot;
/* Make sure drive isn't write protected if user wants to write. */
if (tape->write_prot) {
if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
(filp->f_flags & O_ACCMODE) == O_RDWR) {
clear_bit(IDETAPE_BUSY, &tape->flags);
retval = -EROFS;
goto out_put_tape;
}
}
/*
* Lock the tape drive door so user can't eject.
*/
if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
if (idetape_create_prevent_cmd(drive, &pc, 1)) {
if (!idetape_queue_pc_tail(drive, &pc)) {
if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
tape->door_locked = DOOR_LOCKED;
}
}
}
idetape_restart_speed_control(drive);
tape->restart_speed_control_req = 0;
return 0;
out_put_tape:
ide_tape_put(tape);
return retval;
}
static void idetape_write_release (ide_drive_t *drive, unsigned int minor)
{
idetape_tape_t *tape = drive->driver_data;
idetape_empty_write_pipeline(drive);
tape->merge_stage = __idetape_kmalloc_stage(tape, 1, 0);
if (tape->merge_stage != NULL) {
idetape_pad_zeros(drive, tape->tape_block_size * (tape->user_bs_factor - 1));
__idetape_kfree_stage(tape->merge_stage);
tape->merge_stage = NULL;
}
idetape_write_filemark(drive);
idetape_flush_tape_buffers(drive);
idetape_flush_tape_buffers(drive);
}
/*
* Our character device release function.
*/
static int idetape_chrdev_release (struct inode *inode, struct file *filp)
{
struct ide_tape_obj *tape = ide_tape_f(filp);
ide_drive_t *drive = tape->drive;
idetape_pc_t pc;
unsigned int minor = iminor(inode);
lock_kernel();
tape = drive->driver_data;
debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
idetape_write_release(drive, minor);
if (tape->chrdev_dir == IDETAPE_DIR_READ) {
if (minor < 128)
idetape_discard_read_pipeline(drive, 1);
else
idetape_wait_for_pipeline(drive);
}
if (tape->cache_stage != NULL) {
__idetape_kfree_stage(tape->cache_stage);
tape->cache_stage = NULL;
}
if (minor < 128 && test_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags))
(void) idetape_rewind_tape(drive);
if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
if (tape->door_locked == DOOR_LOCKED) {
if (idetape_create_prevent_cmd(drive, &pc, 0)) {
if (!idetape_queue_pc_tail(drive, &pc))
tape->door_locked = DOOR_UNLOCKED;
}
}
}
clear_bit(IDETAPE_BUSY, &tape->flags);
ide_tape_put(tape);
unlock_kernel();
return 0;
}
/*
* idetape_identify_device is called to check the contents of the
* ATAPI IDENTIFY command results. We return:
*
* 1 If the tape can be supported by us, based on the information
* we have so far.
*
* 0 If this tape driver is not currently supported by us.
*/
static int idetape_identify_device (ide_drive_t *drive)
{
struct idetape_id_gcw gcw;
struct hd_driveid *id = drive->id;
if (drive->id_read == 0)
return 1;
*((unsigned short *) &gcw) = id->config;
/* Check that we can support this device */
if (gcw.protocol != 2)
printk(KERN_ERR "ide-tape: Protocol (0x%02x) is not ATAPI\n",
gcw.protocol);
else if (gcw.device_type != 1)
printk(KERN_ERR "ide-tape: Device type (0x%02x) is not set "
"to tape\n", gcw.device_type);
else if (!gcw.removable)
printk(KERN_ERR "ide-tape: The removable flag is not set\n");
else if (gcw.packet_size != 0) {
printk(KERN_ERR "ide-tape: Packet size (0x%02x) is not 12 "
"bytes long\n", gcw.packet_size);
} else
return 1;
return 0;
}
static void idetape_get_inquiry_results(ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t pc;
char fw_rev[6], vendor_id[10], product_id[18];
idetape_create_inquiry_cmd(&pc);
if (idetape_queue_pc_tail(drive, &pc)) {
printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
tape->name);
return;
}
memcpy(vendor_id, &pc.buffer[8], 8);
memcpy(product_id, &pc.buffer[16], 16);
memcpy(fw_rev, &pc.buffer[32], 4);
ide_fixstring(vendor_id, 10, 0);
ide_fixstring(product_id, 18, 0);
ide_fixstring(fw_rev, 6, 0);
printk(KERN_INFO "ide-tape: %s <-> %s: %s %s rev %s\n",
drive->name, tape->name, vendor_id, product_id, fw_rev);
}
/*
* Ask the tape about its various parameters. In particular, we will adjust our
* data transfer buffer size to the recommended value as returned by the tape.
*/
static void idetape_get_mode_sense_results (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t pc;
u8 *caps;
u8 speed, max_speed;
idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
if (idetape_queue_pc_tail(drive, &pc)) {
printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
" some default values\n");
tape->tape_block_size = 512;
put_unaligned(52, (u16 *)&tape->caps[12]);
put_unaligned(540, (u16 *)&tape->caps[14]);
put_unaligned(6*52, (u16 *)&tape->caps[16]);
return;
}
caps = pc.buffer + 4 + pc.buffer[3];
/* convert to host order and save for later use */
speed = be16_to_cpu(*(u16 *)&caps[14]);
max_speed = be16_to_cpu(*(u16 *)&caps[8]);
put_unaligned(max_speed, (u16 *)&caps[8]);
put_unaligned(be16_to_cpu(*(u16 *)&caps[12]), (u16 *)&caps[12]);
put_unaligned(speed, (u16 *)&caps[14]);
put_unaligned(be16_to_cpu(*(u16 *)&caps[16]), (u16 *)&caps[16]);
if (!speed) {
printk(KERN_INFO "ide-tape: %s: invalid tape speed "
"(assuming 650KB/sec)\n", drive->name);
put_unaligned(650, (u16 *)&caps[14]);
}
if (!max_speed) {
printk(KERN_INFO "ide-tape: %s: invalid max_speed "
"(assuming 650KB/sec)\n", drive->name);
put_unaligned(650, (u16 *)&caps[8]);
}
memcpy(&tape->caps, caps, 20);
if (caps[7] & 0x02)
tape->tape_block_size = 512;
else if (caps[7] & 0x04)
tape->tape_block_size = 1024;
}
#ifdef CONFIG_IDE_PROC_FS
static void idetape_add_settings (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
/*
* drive setting name read/write data type min max mul_factor div_factor data pointer set function
*/
ide_add_setting(drive, "buffer", SETTING_READ, TYPE_SHORT, 0, 0xffff,
1, 2, (u16 *)&tape->caps[16], NULL);
ide_add_setting(drive, "pipeline_min", SETTING_RW, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->min_pipeline, NULL);
ide_add_setting(drive, "pipeline", SETTING_RW, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->max_stages, NULL);
ide_add_setting(drive, "pipeline_max", SETTING_RW, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->max_pipeline, NULL);
ide_add_setting(drive, "pipeline_used", SETTING_READ, TYPE_INT, 0, 0xffff, tape->stage_size / 1024, 1, &tape->nr_stages, NULL);
ide_add_setting(drive, "pipeline_pending", SETTING_READ, TYPE_INT, 0, 0xffff, tape->stage_size / 1024, 1, &tape->nr_pending_stages, NULL);
ide_add_setting(drive, "speed", SETTING_READ, TYPE_SHORT, 0, 0xffff,
1, 1, (u16 *)&tape->caps[14], NULL);
ide_add_setting(drive, "stage", SETTING_READ, TYPE_INT, 0, 0xffff, 1, 1024, &tape->stage_size, NULL);
ide_add_setting(drive, "tdsc", SETTING_RW, TYPE_INT, IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX, 1000, HZ, &tape->best_dsc_rw_frequency, NULL);
ide_add_setting(drive, "dsc_overlap", SETTING_RW, TYPE_BYTE, 0, 1, 1, 1, &drive->dsc_overlap, NULL);
ide_add_setting(drive, "pipeline_head_speed_c",SETTING_READ, TYPE_INT, 0, 0xffff, 1, 1, &tape->controlled_pipeline_head_speed, NULL);
ide_add_setting(drive, "pipeline_head_speed_u",SETTING_READ, TYPE_INT, 0, 0xffff, 1, 1, &tape->uncontrolled_pipeline_head_speed,NULL);
ide_add_setting(drive, "avg_speed", SETTING_READ, TYPE_INT, 0, 0xffff, 1, 1, &tape->avg_speed, NULL);
ide_add_setting(drive, "debug_mask", SETTING_RW, TYPE_INT, 0, 0xffff, 1,
1, &tape->debug_mask, NULL);
}
#else
static inline void idetape_add_settings(ide_drive_t *drive) { ; }
#endif
/*
* ide_setup is called to:
*
* 1. Initialize our various state variables.
* 2. Ask the tape for its capabilities.
* 3. Allocate a buffer which will be used for data
* transfer. The buffer size is chosen based on
* the recommendation which we received in step (2).
*
* Note that at this point ide.c already assigned us an irq, so that
* we can queue requests here and wait for their completion.
*/
static void idetape_setup (ide_drive_t *drive, idetape_tape_t *tape, int minor)
{
unsigned long t1, tmid, tn, t;
int speed;
struct idetape_id_gcw gcw;
int stage_size;
struct sysinfo si;
u16 *ctl = (u16 *)&tape->caps[12];
spin_lock_init(&tape->spinlock);
drive->dsc_overlap = 1;
if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
tape->name);
drive->dsc_overlap = 0;
}
/* Seagate Travan drives do not support DSC overlap. */
if (strstr(drive->id->model, "Seagate STT3401"))
drive->dsc_overlap = 0;
tape->minor = minor;
tape->name[0] = 'h';
tape->name[1] = 't';
tape->name[2] = '0' + minor;
tape->chrdev_dir = IDETAPE_DIR_NONE;
tape->pc = tape->pc_stack;
tape->max_insert_speed = 10000;
tape->speed_control = 1;
*((unsigned short *) &gcw) = drive->id->config;
if (gcw.drq_type == 1)
set_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags);
tape->min_pipeline = tape->max_pipeline = tape->max_stages = 10;
idetape_get_inquiry_results(drive);
idetape_get_mode_sense_results(drive);
ide_tape_get_bsize_from_bdesc(drive);
tape->user_bs_factor = 1;
tape->stage_size = *ctl * tape->tape_block_size;
while (tape->stage_size > 0xffff) {
printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
*ctl /= 2;
tape->stage_size = *ctl * tape->tape_block_size;
}
stage_size = tape->stage_size;
tape->pages_per_stage = stage_size / PAGE_SIZE;
if (stage_size % PAGE_SIZE) {
tape->pages_per_stage++;
tape->excess_bh_size = PAGE_SIZE - stage_size % PAGE_SIZE;
}
/* Select the "best" DSC read/write polling freq and pipeline size. */
speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
tape->max_stages = speed * 1000 * 10 / tape->stage_size;
/*
* Limit memory use for pipeline to 10% of physical memory
*/
si_meminfo(&si);
if (tape->max_stages * tape->stage_size > si.totalram * si.mem_unit / 10)
tape->max_stages = si.totalram * si.mem_unit / (10 * tape->stage_size);
tape->max_stages = min(tape->max_stages, IDETAPE_MAX_PIPELINE_STAGES);
tape->min_pipeline = min(tape->max_stages, IDETAPE_MIN_PIPELINE_STAGES);
tape->max_pipeline = min(tape->max_stages * 2, IDETAPE_MAX_PIPELINE_STAGES);
if (tape->max_stages == 0)
tape->max_stages = tape->min_pipeline = tape->max_pipeline = 1;
t1 = (tape->stage_size * HZ) / (speed * 1000);
tmid = (*(u16 *)&tape->caps[16] * 32 * HZ) / (speed * 125);
tn = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (speed * 1000);
if (tape->max_stages)
t = tn;
else
t = t1;
/*
* Ensure that the number we got makes sense; limit
* it within IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
*/
tape->best_dsc_rw_frequency = max_t(unsigned long, min_t(unsigned long, t, IDETAPE_DSC_RW_MAX), IDETAPE_DSC_RW_MIN);
printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
"%dkB pipeline, %lums tDSC%s\n",
drive->name, tape->name, *(u16 *)&tape->caps[14],
(*(u16 *)&tape->caps[16] * 512) / tape->stage_size,
tape->stage_size / 1024,
tape->max_stages * tape->stage_size / 1024,
tape->best_dsc_rw_frequency * 1000 / HZ,
drive->using_dma ? ", DMA":"");
idetape_add_settings(drive);
}
static void ide_tape_remove(ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
ide_proc_unregister_driver(drive, tape->driver);
ide_unregister_region(tape->disk);
ide_tape_put(tape);
}
static void ide_tape_release(struct kref *kref)
{
struct ide_tape_obj *tape = to_ide_tape(kref);
ide_drive_t *drive = tape->drive;
struct gendisk *g = tape->disk;
BUG_ON(tape->first_stage != NULL || tape->merge_stage_size);
drive->dsc_overlap = 0;
drive->driver_data = NULL;
device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor + 128));
idetape_devs[tape->minor] = NULL;
g->private_data = NULL;
put_disk(g);
kfree(tape);
}
#ifdef CONFIG_IDE_PROC_FS
static int proc_idetape_read_name
(char *page, char **start, off_t off, int count, int *eof, void *data)
{
ide_drive_t *drive = (ide_drive_t *) data;
idetape_tape_t *tape = drive->driver_data;
char *out = page;
int len;
len = sprintf(out, "%s\n", tape->name);
PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
}
static ide_proc_entry_t idetape_proc[] = {
{ "capacity", S_IFREG|S_IRUGO, proc_ide_read_capacity, NULL },
{ "name", S_IFREG|S_IRUGO, proc_idetape_read_name, NULL },
{ NULL, 0, NULL, NULL }
};
#endif
static int ide_tape_probe(ide_drive_t *);
static ide_driver_t idetape_driver = {
.gen_driver = {
.owner = THIS_MODULE,
.name = "ide-tape",
.bus = &ide_bus_type,
},
.probe = ide_tape_probe,
.remove = ide_tape_remove,
.version = IDETAPE_VERSION,
.media = ide_tape,
.supports_dsc_overlap = 1,
.do_request = idetape_do_request,
.end_request = idetape_end_request,
.error = __ide_error,
.abort = __ide_abort,
#ifdef CONFIG_IDE_PROC_FS
.proc = idetape_proc,
#endif
};
/*
* Our character device supporting functions, passed to register_chrdev.
*/
static const struct file_operations idetape_fops = {
.owner = THIS_MODULE,
.read = idetape_chrdev_read,
.write = idetape_chrdev_write,
.ioctl = idetape_chrdev_ioctl,
.open = idetape_chrdev_open,
.release = idetape_chrdev_release,
};
static int idetape_open(struct inode *inode, struct file *filp)
{
struct gendisk *disk = inode->i_bdev->bd_disk;
struct ide_tape_obj *tape;
if (!(tape = ide_tape_get(disk)))
return -ENXIO;
return 0;
}
static int idetape_release(struct inode *inode, struct file *filp)
{
struct gendisk *disk = inode->i_bdev->bd_disk;
struct ide_tape_obj *tape = ide_tape_g(disk);
ide_tape_put(tape);
return 0;
}
static int idetape_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct block_device *bdev = inode->i_bdev;
struct ide_tape_obj *tape = ide_tape_g(bdev->bd_disk);
ide_drive_t *drive = tape->drive;
int err = generic_ide_ioctl(drive, file, bdev, cmd, arg);
if (err == -EINVAL)
err = idetape_blkdev_ioctl(drive, cmd, arg);
return err;
}
static struct block_device_operations idetape_block_ops = {
.owner = THIS_MODULE,
.open = idetape_open,
.release = idetape_release,
.ioctl = idetape_ioctl,
};
static int ide_tape_probe(ide_drive_t *drive)
{
idetape_tape_t *tape;
struct gendisk *g;
int minor;
if (!strstr("ide-tape", drive->driver_req))
goto failed;
if (!drive->present)
goto failed;
if (drive->media != ide_tape)
goto failed;
if (!idetape_identify_device (drive)) {
printk(KERN_ERR "ide-tape: %s: not supported by this version of ide-tape\n", drive->name);
goto failed;
}
if (drive->scsi) {
printk("ide-tape: passing drive %s to ide-scsi emulation.\n", drive->name);
goto failed;
}
if (strstr(drive->id->model, "OnStream DI-")) {
printk(KERN_WARNING "ide-tape: Use drive %s with ide-scsi emulation and osst.\n", drive->name);
printk(KERN_WARNING "ide-tape: OnStream support will be removed soon from ide-tape!\n");
}
tape = kzalloc(sizeof (idetape_tape_t), GFP_KERNEL);
if (tape == NULL) {
printk(KERN_ERR "ide-tape: %s: Can't allocate a tape structure\n", drive->name);
goto failed;
}
g = alloc_disk(1 << PARTN_BITS);
if (!g)
goto out_free_tape;
ide_init_disk(g, drive);
ide_proc_register_driver(drive, &idetape_driver);
kref_init(&tape->kref);
tape->drive = drive;
tape->driver = &idetape_driver;
tape->disk = g;
g->private_data = &tape->driver;
drive->driver_data = tape;
mutex_lock(&idetape_ref_mutex);
for (minor = 0; idetape_devs[minor]; minor++)
;
idetape_devs[minor] = tape;
mutex_unlock(&idetape_ref_mutex);
idetape_setup(drive, tape, minor);
device_create(idetape_sysfs_class, &drive->gendev,
MKDEV(IDETAPE_MAJOR, minor), "%s", tape->name);
device_create(idetape_sysfs_class, &drive->gendev,
MKDEV(IDETAPE_MAJOR, minor + 128), "n%s", tape->name);
g->fops = &idetape_block_ops;
ide_register_region(g);
return 0;
out_free_tape:
kfree(tape);
failed:
return -ENODEV;
}
MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
MODULE_LICENSE("GPL");
static void __exit idetape_exit (void)
{
driver_unregister(&idetape_driver.gen_driver);
class_destroy(idetape_sysfs_class);
unregister_chrdev(IDETAPE_MAJOR, "ht");
}
static int __init idetape_init(void)
{
int error = 1;
idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
if (IS_ERR(idetape_sysfs_class)) {
idetape_sysfs_class = NULL;
printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
error = -EBUSY;
goto out;
}
if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
printk(KERN_ERR "ide-tape: Failed to register character device interface\n");
error = -EBUSY;
goto out_free_class;
}
error = driver_register(&idetape_driver.gen_driver);
if (error)
goto out_free_driver;
return 0;
out_free_driver:
driver_unregister(&idetape_driver.gen_driver);
out_free_class:
class_destroy(idetape_sysfs_class);
out:
return error;
}
MODULE_ALIAS("ide:*m-tape*");
module_init(idetape_init);
module_exit(idetape_exit);
MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
