/*
* dell_rbu.c
* Bios Update driver for Dell systems
* Author: Dell Inc
* Abhay Salunke <abhay_salunke@dell.com>
*
* Copyright (C) 2005 Dell Inc.
*
* Remote BIOS Update (rbu) driver is used for updating DELL BIOS by
* creating entries in the /sys file systems on Linux 2.6 and higher
* kernels. The driver supports two mechanism to update the BIOS namely
* contiguous and packetized. Both these methods still require having some
* application to set the CMOS bit indicating the BIOS to update itself
* after a reboot.
*
* Contiguous method:
* This driver writes the incoming data in a monolithic image by allocating
* contiguous physical pages large enough to accommodate the incoming BIOS
* image size.
*
* Packetized method:
* The driver writes the incoming packet image by allocating a new packet
* on every time the packet data is written. This driver requires an
* application to break the BIOS image in to fixed sized packet chunks.
*
* See Documentation/dell_rbu.txt for more info.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License v2.0 as published by
* the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/version.h>
#include <linux/config.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/blkdev.h>
#include <linux/device.h>
#include <linux/spinlock.h>
#include <linux/moduleparam.h>
#include <linux/firmware.h>
#include <linux/dma-mapping.h>
MODULE_AUTHOR("Abhay Salunke <abhay_salunke@dell.com>");
MODULE_DESCRIPTION("Driver for updating BIOS image on DELL systems");
MODULE_LICENSE("GPL");
MODULE_VERSION("2.0");
#define BIOS_SCAN_LIMIT 0xffffffff
#define MAX_IMAGE_LENGTH 16
static struct _rbu_data {
void *image_update_buffer;
unsigned long image_update_buffer_size;
unsigned long bios_image_size;
int image_update_ordernum;
int dma_alloc;
spinlock_t lock;
unsigned long packet_read_count;
unsigned long packet_write_count;
unsigned long num_packets;
unsigned long packetsize;
int entry_created;
} rbu_data;
static char image_type[MAX_IMAGE_LENGTH + 1] = "mono";
module_param_string(image_type, image_type, sizeof (image_type), 0);
MODULE_PARM_DESC(image_type, "BIOS image type. choose- mono or packet");
struct packet_data {
struct list_head list;
size_t length;
void *data;
int ordernum;
};
static struct packet_data packet_data_head;
static struct platform_device *rbu_device;
static int context;
static dma_addr_t dell_rbu_dmaaddr;
static void init_packet_head(void)
{
INIT_LIST_HEAD(&packet_data_head.list);
rbu_data.packet_write_count = 0;
rbu_data.packet_read_count = 0;
rbu_data.num_packets = 0;
rbu_data.packetsize = 0;
}
static int fill_last_packet(void *data, size_t length)
{
struct list_head *ptemp_list;
struct packet_data *packet = NULL;
int packet_count = 0;
pr_debug("fill_last_packet: entry \n");
if (!rbu_data.num_packets) {
pr_debug("fill_last_packet: num_packets=0\n");
return -ENOMEM;
}
packet_count = rbu_data.num_packets;
ptemp_list = (&packet_data_head.list)->prev;
packet = list_entry(ptemp_list, struct packet_data, list);
if ((rbu_data.packet_write_count + length) > rbu_data.packetsize) {
pr_debug("dell_rbu:%s: packet size data "
"overrun\n", __FUNCTION__);
return -EINVAL;
}
pr_debug("fill_last_packet : buffer = %p\n", packet->data);
memcpy((packet->data + rbu_data.packet_write_count), data, length);
if ((rbu_data.packet_write_count + length) == rbu_data.packetsize) {
/*
* this was the last data chunk in the packet
* so reinitialize the packet data counter to zero
*/
rbu_data.packet_write_count = 0;
} else
rbu_data.packet_write_count += length;
pr_debug("fill_last_packet: exit \n");
return 0;
}
static int create_packet(size_t length)
{
struct packet_data *newpacket;
int ordernum = 0;
pr_debug("create_packet: entry \n");
if (!rbu_data.packetsize) {
pr_debug("create_packet: packetsize not specified\n");
return -EINVAL;
}
spin_unlock(&rbu_data.lock);
newpacket = kmalloc(sizeof (struct packet_data), GFP_KERNEL);
spin_lock(&rbu_data.lock);
if (!newpacket) {
printk(KERN_WARNING
"dell_rbu:%s: failed to allocate new "
"packet\n", __FUNCTION__);
return -ENOMEM;
}
ordernum = get_order(length);
/*
* there is no upper limit on memory
* address for packetized mechanism
*/
spin_unlock(&rbu_data.lock);
newpacket->data = (unsigned char *) __get_free_pages(GFP_KERNEL,
ordernum);
spin_lock(&rbu_data.lock);
pr_debug("create_packet: newpacket %p\n", newpacket->data);
if (!newpacket->data) {
printk(KERN_WARNING
"dell_rbu:%s: failed to allocate new "
"packet\n", __FUNCTION__);
kfree(newpacket);
return -ENOMEM;
}
newpacket->ordernum = ordernum;
++rbu_data.num_packets;
/*
* initialize the newly created packet headers
*/
INIT_LIST_HEAD(&newpacket->list);
list_add_tail(&newpacket->list, &packet_data_head.list);
/*
* packets have fixed size
*/
newpacket->length = rbu_data.packetsize;
pr_debug("create_packet: exit \n");
return 0;
}
static int packetize_data(void *data, size_t length)
{
int rc = 0;
if (!rbu_data.packet_write_count) {
if ((rc = create_packet(length)))
return rc;
}
if ((rc = fill_last_packet(data, length)))
return rc;
return rc;
}
static int do_packet_read(char *data, struct list_head *ptemp_list,
int length, int bytes_read, int *list_read_count)
{
void *ptemp_buf;
struct packet_data *newpacket = NULL;
int bytes_copied = 0;
int j = 0;
newpacket = list_entry(ptemp_list, struct packet_data, list);
*list_read_count += newpacket->length;
if (*list_read_count > bytes_read) {
/* point to the start of unread data */
j = newpacket->length - (*list_read_count - bytes_read);
/* point to the offset in the packet buffer */
ptemp_buf = (u8 *) newpacket->data + j;
/*
* check if there is enough room in
* * the incoming buffer
*/
if (length > (*list_read_count - bytes_read))
/*
* copy what ever is there in this
* packet and move on
*/
bytes_copied = (*list_read_count - bytes_read);
else
/* copy the remaining */
bytes_copied = length;
memcpy(data, ptemp_buf, bytes_copied);
}
return bytes_copied;
}
static int packet_read_list(char *data, size_t *pread_length)
{
struct list_head *ptemp_list;
int temp_count = 0;
int bytes_copied = 0;
int bytes_read = 0;
int remaining_bytes = 0;
char *pdest = data;
/* check if we have any packets */
if (0 == rbu_data.num_packets)
return -ENOMEM;
remaining_bytes = *pread_length;
bytes_read = rbu_data.packet_read_count;
ptemp_list = (&packet_data_head.list)->next;
while (!list_empty(ptemp_list)) {
bytes_copied = do_packet_read(pdest, ptemp_list,
remaining_bytes, bytes_read, &temp_count);
remaining_bytes -= bytes_copied;
bytes_read += bytes_copied;
pdest += bytes_copied;
/*
* check if we reached end of buffer before reaching the
* last packet
*/
if (remaining_bytes == 0)
break;
ptemp_list = ptemp_list->next;
}
/*finally set the bytes read */
*pread_length = bytes_read - rbu_data.packet_read_count;
rbu_data.packet_read_count = bytes_read;
return 0;
}
static void packet_empty_list(void)
{
struct list_head *ptemp_list;
struct list_head *pnext_list;
struct packet_data *newpacket;
ptemp_list = (&packet_data_head.list)->next;
while (!list_empty(ptemp_list)) {
newpacket =
list_entry(ptemp_list, struct packet_data, list);
pnext_list = ptemp_list->next;
list_del(ptemp_list);
ptemp_list = pnext_list;
/*
* zero out the RBU packet memory before freeing
* to make sure there are no stale RBU packets left in memory
*/
memset(newpacket->data, 0, rbu_data.packetsize);
free_pages((unsigned long) newpacket->data,
newpacket->ordernum);
kfree(newpacket);
}
rbu_data.packet_write_count = 0;
rbu_data.packet_read_count = 0;
rbu_data.num_packets = 0;
rbu_data.packetsize = 0;
}
/*
* img_update_free: Frees the buffer allocated for storing BIOS image
* Always called with lock held and returned with lock held
*/
static void img_update_free(void)
{
if (!rbu_data.image_update_buffer)
return;
/*
* zero out this buffer before freeing it to get rid of any stale
* BIOS image copied in memory.
*/
memset(rbu_data.image_update_buffer, 0,
rbu_data.image_update_buffer_size);
if (rbu_data.dma_alloc == 1)
dma_free_coherent(NULL, rbu_data.bios_image_size,
rbu_data.image_update_buffer, dell_rbu_dmaaddr);
else
free_pages((unsigned long) rbu_data.image_update_buffer,
rbu_data.image_update_ordernum);
/*
* Re-initialize the rbu_data variables after a free
*/
rbu_data.image_update_ordernum = -1;
rbu_data.image_update_buffer = NULL;
rbu_data.image_update_buffer_size = 0;
rbu_data.bios_image_size = 0;
rbu_data.dma_alloc = 0;
}
/*
* img_update_realloc: This function allocates the contiguous pages to
* accommodate the requested size of data. The memory address and size
* values are stored globally and on every call to this function the new
* size is checked to see if more data is required than the existing size.
* If true the previous memory is freed and new allocation is done to
* accommodate the new size. If the incoming size is less then than the
* already allocated size, then that memory is reused. This function is
* called with lock held and returns with lock held.
*/
static int img_update_realloc(unsigned long size)
{
unsigned char *image_update_buffer = NULL;
unsigned long rc;
unsigned long img_buf_phys_addr;
int ordernum;
int dma_alloc = 0;
/*
* check if the buffer of sufficient size has been
* already allocated
*/
if (rbu_data.image_update_buffer_size >= size) {
/*
* check for corruption
*/
if ((size != 0) && (rbu_data.image_update_buffer == NULL)) {
printk(KERN_ERR "dell_rbu:%s: corruption "
"check failed\n", __FUNCTION__);
return -EINVAL;
}
/*
* we have a valid pre-allocated buffer with
* sufficient size
*/
return 0;
}
/*
* free any previously allocated buffer
*/
img_update_free();
spin_unlock(&rbu_data.lock);
ordernum = get_order(size);
image_update_buffer =
(unsigned char *) __get_free_pages(GFP_KERNEL, ordernum);
img_buf_phys_addr =
(unsigned long) virt_to_phys(image_update_buffer);
if (img_buf_phys_addr > BIOS_SCAN_LIMIT) {
free_pages((unsigned long) image_update_buffer, ordernum);
ordernum = -1;
image_update_buffer = dma_alloc_coherent(NULL, size,
&dell_rbu_dmaaddr, GFP_KERNEL);
dma_alloc = 1;
}
spin_lock(&rbu_data.lock);
if (image_update_buffer != NULL) {
rbu_data.image_update_buffer = image_update_buffer;
rbu_data.image_update_buffer_size = size;
rbu_data.bios_image_size =
rbu_data.image_update_buffer_size;
rbu_data.image_update_ordernum = ordernum;
rbu_data.dma_alloc = dma_alloc;
rc = 0;
} else {
pr_debug("Not enough memory for image update:"
"size = %ld\n", size);
rc = -ENOMEM;
}
return rc;
}
static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)
{
int retval;
size_t bytes_left;
size_t data_length;
char *ptempBuf = buffer;
unsigned long imagesize;
/* check to see if we have something to return */
if (rbu_data.num_packets == 0) {
pr_debug("read_packet_data: no packets written\n");
retval = -ENOMEM;
goto read_rbu_data_exit;
}
imagesize = rbu_data.num_packets * rbu_data.packetsize;
if (pos > imagesize) {
retval = 0;
printk(KERN_WARNING "dell_rbu:read_packet_data: "
"data underrun\n");
goto read_rbu_data_exit;
}
bytes_left = imagesize - pos;
data_length = min(bytes_left, count);
if ((retval = packet_read_list(ptempBuf, &data_length)) < 0)
goto read_rbu_data_exit;
if ((pos + count) > imagesize) {
rbu_data.packet_read_count = 0;
/* this was the last copy */
retval = bytes_left;
} else
retval = count;
read_rbu_data_exit:
return retval;
}
static ssize_t read_rbu_mono_data(char *buffer, loff_t pos, size_t count)
{
unsigned char *ptemp = NULL;
size_t bytes_left = 0;
size_t data_length = 0;
ssize_t ret_count = 0;
/* check to see if we have something to return */
if ((rbu_data.image_update_buffer == NULL) ||
(rbu_data.bios_image_size == 0)) {
pr_debug("read_rbu_data_mono: image_update_buffer %p ,"
"bios_image_size %lu\n",
rbu_data.image_update_buffer,
rbu_data.bios_image_size);
ret_count = -ENOMEM;
goto read_rbu_data_exit;
}
if (pos > rbu_data.bios_image_size) {
ret_count = 0;
goto read_rbu_data_exit;
}
bytes_left = rbu_data.bios_image_size - pos;
data_length = min(bytes_left, count);
ptemp = rbu_data.image_update_buffer;
memcpy(buffer, (ptemp + pos), data_length);
if ((pos + count) > rbu_data.bios_image_size)
/* this was the last copy */
ret_count = bytes_left;
else
ret_count = count;
read_rbu_data_exit:
return ret_count;
}
static ssize_t read_rbu_data(struct kobject *kobj, char *buffer,
loff_t pos, size_t count)
{
ssize_t ret_count = 0;
spin_lock(&rbu_data.lock);
if (!strcmp(image_type, "mono"))
ret_count = read_rbu_mono_data(buffer, pos, count);
else if (!strcmp(image_type, "packet"))
ret_count = read_packet_data(buffer, pos, count);
else
pr_debug("read_rbu_data: invalid image type specified\n");
spin_unlock(&rbu_data.lock);
return ret_count;
}
static void callbackfn_rbu(const struct firmware *fw, void *context)
{
int rc = 0;
if (!fw || !fw->size) {
rbu_data.entry_created = 0;
return;
}
spin_lock(&rbu_data.lock);
if (!strcmp(image_type, "mono")) {
if (!img_update_realloc(fw->size))
memcpy(rbu_data.image_update_buffer,
fw->data, fw->size);
} else if (!strcmp(image_type, "packet")) {
if (!rbu_data.packetsize)
rbu_data.packetsize = fw->size;
else if (rbu_data.packetsize != fw->size) {
packet_empty_list();
rbu_data.packetsize = fw->size;
}
packetize_data(fw->data, fw->size);
} else
pr_debug("invalid image type specified.\n");
spin_unlock(&rbu_data.lock);
rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG,
"dell_rbu", &rbu_device->dev, &context, callbackfn_rbu);
if (rc)
printk(KERN_ERR
"dell_rbu:%s request_firmware_nowait failed"
" %d\n", __FUNCTION__, rc);
else
rbu_data.entry_created = 1;
}
static ssize_t read_rbu_image_type(struct kobject *kobj, char *buffer,
loff_t pos, size_t count)
{
int size = 0;
if (!pos)
size = sprintf(buffer, "%s\n", image_type);
return size;
}
static ssize_t write_rbu_image_type(struct kobject *kobj, char *buffer,
loff_t pos, size_t count)
{
int rc = count;
int req_firm_rc = 0;
int i;
spin_lock(&rbu_data.lock);
/*
* Find the first newline or space
*/
for (i = 0; i < count; ++i)
if (buffer[i] == '\n' || buffer[i] == ' ') {
buffer[i] = '\0';
break;
}
if (i == count)
buffer[count] = '\0';
if (strstr(buffer, "mono"))
strcpy(image_type, "mono");
else if (strstr(buffer, "packet"))
strcpy(image_type, "packet");
else if (strstr(buffer, "init")) {
/*
* If due to the user error the driver gets in a bad
* state where even though it is loaded , the
* /sys/class/firmware/dell_rbu entries are missing.
* to cover this situation the user can recreate entries
* by writing init to image_type.
*/
if (!rbu_data.entry_created) {
spin_unlock(&rbu_data.lock);
req_firm_rc = request_firmware_nowait(THIS_MODULE,
FW_ACTION_NOHOTPLUG, "dell_rbu",
&rbu_device->dev, &context,
callbackfn_rbu);
if (req_firm_rc) {
printk(KERN_ERR
"dell_rbu:%s request_firmware_nowait"
" failed %d\n", __FUNCTION__, rc);
rc = -EIO;
} else
rbu_data.entry_created = 1;
spin_lock(&rbu_data.lock);
}
} else {
printk(KERN_WARNING "dell_rbu: image_type is invalid\n");
spin_unlock(&rbu_data.lock);
return -EINVAL;
}
/* we must free all previous allocations */
packet_empty_list();
img_update_free();
spin_unlock(&rbu_data.lock);
return rc;
}
static struct bin_attribute rbu_data_attr = {
.attr = {
.name = "data",
.owner = THIS_MODULE,
.mode = 0444,
},
.read = read_rbu_data,
};
static struct bin_attribute rbu_image_type_attr = {
.attr = {
.name = "image_type",
.owner = THIS_MODULE,
.mode = 0644,
},
.read = read_rbu_image_type,
.write = write_rbu_image_type,
};
static int __init dcdrbu_init(void)
{
int rc = 0;
spin_lock_init(&rbu_data.lock);
init_packet_head();
rbu_device =
platform_device_register_simple("dell_rbu", -1, NULL, 0);
if (!rbu_device) {
printk(KERN_ERR
"dell_rbu:%s:platform_device_register_simple "
"failed\n", __FUNCTION__);
return -EIO;
}
sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_data_attr);
sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_image_type_attr);
rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG,
"dell_rbu", &rbu_device->dev, &context, callbackfn_rbu);
if (rc)
printk(KERN_ERR "dell_rbu:%s:request_firmware_nowait"
" failed %d\n", __FUNCTION__, rc);
else
rbu_data.entry_created = 1;
return rc;
}
static __exit void dcdrbu_exit(void)
{
spin_lock(&rbu_data.lock);
packet_empty_list();
img_update_free();
spin_unlock(&rbu_data.lock);
platform_device_unregister(rbu_device);
}
module_exit(dcdrbu_exit);
module_init(dcdrbu_init);
