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-rw-r--r--drivers/scsi/hosts.c462
1 files changed, 462 insertions, 0 deletions
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
new file mode 100644
index 000000000000..ba347576d99b
--- /dev/null
+++ b/drivers/scsi/hosts.c
@@ -0,0 +1,462 @@
+/*
+ * hosts.c Copyright (C) 1992 Drew Eckhardt
+ * Copyright (C) 1993, 1994, 1995 Eric Youngdale
+ * Copyright (C) 2002-2003 Christoph Hellwig
+ *
+ * mid to lowlevel SCSI driver interface
+ * Initial versions: Drew Eckhardt
+ * Subsequent revisions: Eric Youngdale
+ *
+ * <drew@colorado.edu>
+ *
+ * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
+ * Added QLOGIC QLA1280 SCSI controller kernel host support.
+ * August 4, 1999 Fred Lewis, Intel DuPont
+ *
+ * Updated to reflect the new initialization scheme for the higher
+ * level of scsi drivers (sd/sr/st)
+ * September 17, 2000 Torben Mathiasen <tmm@image.dk>
+ *
+ * Restructured scsi_host lists and associated functions.
+ * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
+ */
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/completion.h>
+#include <linux/transport_class.h>
+
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_transport.h>
+
+#include "scsi_priv.h"
+#include "scsi_logging.h"
+
+
+static int scsi_host_next_hn; /* host_no for next new host */
+
+
+static void scsi_host_cls_release(struct class_device *class_dev)
+{
+ put_device(&class_to_shost(class_dev)->shost_gendev);
+}
+
+static struct class shost_class = {
+ .name = "scsi_host",
+ .release = scsi_host_cls_release,
+};
+
+/**
+ * scsi_host_cancel - cancel outstanding IO to this host
+ * @shost: pointer to struct Scsi_Host
+ * recovery: recovery requested to run.
+ **/
+void scsi_host_cancel(struct Scsi_Host *shost, int recovery)
+{
+ struct scsi_device *sdev;
+
+ set_bit(SHOST_CANCEL, &shost->shost_state);
+ shost_for_each_device(sdev, shost) {
+ scsi_device_cancel(sdev, recovery);
+ }
+ wait_event(shost->host_wait, (!test_bit(SHOST_RECOVERY,
+ &shost->shost_state)));
+}
+
+/**
+ * scsi_remove_host - remove a scsi host
+ * @shost: a pointer to a scsi host to remove
+ **/
+void scsi_remove_host(struct Scsi_Host *shost)
+{
+ scsi_forget_host(shost);
+ scsi_host_cancel(shost, 0);
+ scsi_proc_host_rm(shost);
+
+ set_bit(SHOST_DEL, &shost->shost_state);
+
+ transport_unregister_device(&shost->shost_gendev);
+ class_device_unregister(&shost->shost_classdev);
+ device_del(&shost->shost_gendev);
+}
+EXPORT_SYMBOL(scsi_remove_host);
+
+/**
+ * scsi_add_host - add a scsi host
+ * @shost: scsi host pointer to add
+ * @dev: a struct device of type scsi class
+ *
+ * Return value:
+ * 0 on success / != 0 for error
+ **/
+int scsi_add_host(struct Scsi_Host *shost, struct device *dev)
+{
+ struct scsi_host_template *sht = shost->hostt;
+ int error = -EINVAL;
+
+ printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
+ sht->info ? sht->info(shost) : sht->name);
+
+ if (!shost->can_queue) {
+ printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
+ sht->name);
+ goto out;
+ }
+
+ if (!shost->shost_gendev.parent)
+ shost->shost_gendev.parent = dev ? dev : &platform_bus;
+
+ error = device_add(&shost->shost_gendev);
+ if (error)
+ goto out;
+
+ set_bit(SHOST_ADD, &shost->shost_state);
+ get_device(shost->shost_gendev.parent);
+
+ error = class_device_add(&shost->shost_classdev);
+ if (error)
+ goto out_del_gendev;
+
+ get_device(&shost->shost_gendev);
+
+ if (shost->transportt->host_size &&
+ (shost->shost_data = kmalloc(shost->transportt->host_size,
+ GFP_KERNEL)) == NULL)
+ goto out_del_classdev;
+
+ if (shost->transportt->create_work_queue) {
+ snprintf(shost->work_q_name, KOBJ_NAME_LEN, "scsi_wq_%d",
+ shost->host_no);
+ shost->work_q = create_singlethread_workqueue(
+ shost->work_q_name);
+ if (!shost->work_q)
+ goto out_free_shost_data;
+ }
+
+ error = scsi_sysfs_add_host(shost);
+ if (error)
+ goto out_destroy_host;
+
+ scsi_proc_host_add(shost);
+ return error;
+
+ out_destroy_host:
+ if (shost->work_q)
+ destroy_workqueue(shost->work_q);
+ out_free_shost_data:
+ kfree(shost->shost_data);
+ out_del_classdev:
+ class_device_del(&shost->shost_classdev);
+ out_del_gendev:
+ device_del(&shost->shost_gendev);
+ out:
+ return error;
+}
+EXPORT_SYMBOL(scsi_add_host);
+
+static void scsi_host_dev_release(struct device *dev)
+{
+ struct Scsi_Host *shost = dev_to_shost(dev);
+ struct device *parent = dev->parent;
+
+ if (shost->ehandler) {
+ DECLARE_COMPLETION(sem);
+ shost->eh_notify = &sem;
+ shost->eh_kill = 1;
+ up(shost->eh_wait);
+ wait_for_completion(&sem);
+ shost->eh_notify = NULL;
+ }
+
+ if (shost->work_q)
+ destroy_workqueue(shost->work_q);
+
+ scsi_proc_hostdir_rm(shost->hostt);
+ scsi_destroy_command_freelist(shost);
+ kfree(shost->shost_data);
+
+ /*
+ * Some drivers (eg aha1542) do scsi_register()/scsi_unregister()
+ * during probing without performing a scsi_set_device() in between.
+ * In this case dev->parent is NULL.
+ */
+ if (parent)
+ put_device(parent);
+ kfree(shost);
+}
+
+/**
+ * scsi_host_alloc - register a scsi host adapter instance.
+ * @sht: pointer to scsi host template
+ * @privsize: extra bytes to allocate for driver
+ *
+ * Note:
+ * Allocate a new Scsi_Host and perform basic initialization.
+ * The host is not published to the scsi midlayer until scsi_add_host
+ * is called.
+ *
+ * Return value:
+ * Pointer to a new Scsi_Host
+ **/
+struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
+{
+ struct Scsi_Host *shost;
+ int gfp_mask = GFP_KERNEL, rval;
+ DECLARE_COMPLETION(complete);
+
+ if (sht->unchecked_isa_dma && privsize)
+ gfp_mask |= __GFP_DMA;
+
+ /* Check to see if this host has any error handling facilities */
+ if (!sht->eh_strategy_handler && !sht->eh_abort_handler &&
+ !sht->eh_device_reset_handler && !sht->eh_bus_reset_handler &&
+ !sht->eh_host_reset_handler) {
+ printk(KERN_ERR "ERROR: SCSI host `%s' has no error handling\n"
+ "ERROR: This is not a safe way to run your "
+ "SCSI host\n"
+ "ERROR: The error handling must be added to "
+ "this driver\n", sht->proc_name);
+ dump_stack();
+ }
+
+ shost = kmalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
+ if (!shost)
+ return NULL;
+ memset(shost, 0, sizeof(struct Scsi_Host) + privsize);
+
+ spin_lock_init(&shost->default_lock);
+ scsi_assign_lock(shost, &shost->default_lock);
+ INIT_LIST_HEAD(&shost->__devices);
+ INIT_LIST_HEAD(&shost->__targets);
+ INIT_LIST_HEAD(&shost->eh_cmd_q);
+ INIT_LIST_HEAD(&shost->starved_list);
+ init_waitqueue_head(&shost->host_wait);
+
+ init_MUTEX(&shost->scan_mutex);
+
+ shost->host_no = scsi_host_next_hn++; /* XXX(hch): still racy */
+ shost->dma_channel = 0xff;
+
+ /* These three are default values which can be overridden */
+ shost->max_channel = 0;
+ shost->max_id = 8;
+ shost->max_lun = 8;
+
+ /* Give each shost a default transportt */
+ shost->transportt = &blank_transport_template;
+
+ /*
+ * All drivers right now should be able to handle 12 byte
+ * commands. Every so often there are requests for 16 byte
+ * commands, but individual low-level drivers need to certify that
+ * they actually do something sensible with such commands.
+ */
+ shost->max_cmd_len = 12;
+ shost->hostt = sht;
+ shost->this_id = sht->this_id;
+ shost->can_queue = sht->can_queue;
+ shost->sg_tablesize = sht->sg_tablesize;
+ shost->cmd_per_lun = sht->cmd_per_lun;
+ shost->unchecked_isa_dma = sht->unchecked_isa_dma;
+ shost->use_clustering = sht->use_clustering;
+ shost->ordered_flush = sht->ordered_flush;
+ shost->ordered_tag = sht->ordered_tag;
+
+ /*
+ * hosts/devices that do queueing must support ordered tags
+ */
+ if (shost->can_queue > 1 && shost->ordered_flush) {
+ printk(KERN_ERR "scsi: ordered flushes don't support queueing\n");
+ shost->ordered_flush = 0;
+ }
+
+ if (sht->max_host_blocked)
+ shost->max_host_blocked = sht->max_host_blocked;
+ else
+ shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
+
+ /*
+ * If the driver imposes no hard sector transfer limit, start at
+ * machine infinity initially.
+ */
+ if (sht->max_sectors)
+ shost->max_sectors = sht->max_sectors;
+ else
+ shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
+
+ /*
+ * assume a 4GB boundary, if not set
+ */
+ if (sht->dma_boundary)
+ shost->dma_boundary = sht->dma_boundary;
+ else
+ shost->dma_boundary = 0xffffffff;
+
+ rval = scsi_setup_command_freelist(shost);
+ if (rval)
+ goto fail_kfree;
+
+ device_initialize(&shost->shost_gendev);
+ snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d",
+ shost->host_no);
+ shost->shost_gendev.release = scsi_host_dev_release;
+
+ class_device_initialize(&shost->shost_classdev);
+ shost->shost_classdev.dev = &shost->shost_gendev;
+ shost->shost_classdev.class = &shost_class;
+ snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d",
+ shost->host_no);
+
+ shost->eh_notify = &complete;
+ rval = kernel_thread(scsi_error_handler, shost, 0);
+ if (rval < 0)
+ goto fail_destroy_freelist;
+ wait_for_completion(&complete);
+ shost->eh_notify = NULL;
+
+ scsi_proc_hostdir_add(shost->hostt);
+ return shost;
+
+ fail_destroy_freelist:
+ scsi_destroy_command_freelist(shost);
+ fail_kfree:
+ kfree(shost);
+ return NULL;
+}
+EXPORT_SYMBOL(scsi_host_alloc);
+
+struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
+{
+ struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
+
+ if (!sht->detect) {
+ printk(KERN_WARNING "scsi_register() called on new-style "
+ "template for driver %s\n", sht->name);
+ dump_stack();
+ }
+
+ if (shost)
+ list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
+ return shost;
+}
+EXPORT_SYMBOL(scsi_register);
+
+void scsi_unregister(struct Scsi_Host *shost)
+{
+ list_del(&shost->sht_legacy_list);
+ scsi_host_put(shost);
+}
+EXPORT_SYMBOL(scsi_unregister);
+
+/**
+ * scsi_host_lookup - get a reference to a Scsi_Host by host no
+ *
+ * @hostnum: host number to locate
+ *
+ * Return value:
+ * A pointer to located Scsi_Host or NULL.
+ **/
+struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
+{
+ struct class *class = &shost_class;
+ struct class_device *cdev;
+ struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p;
+
+ down_read(&class->subsys.rwsem);
+ list_for_each_entry(cdev, &class->children, node) {
+ p = class_to_shost(cdev);
+ if (p->host_no == hostnum) {
+ shost = scsi_host_get(p);
+ break;
+ }
+ }
+ up_read(&class->subsys.rwsem);
+
+ return shost;
+}
+EXPORT_SYMBOL(scsi_host_lookup);
+
+/**
+ * scsi_host_get - inc a Scsi_Host ref count
+ * @shost: Pointer to Scsi_Host to inc.
+ **/
+struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
+{
+ if (test_bit(SHOST_DEL, &shost->shost_state) ||
+ !get_device(&shost->shost_gendev))
+ return NULL;
+ return shost;
+}
+EXPORT_SYMBOL(scsi_host_get);
+
+/**
+ * scsi_host_put - dec a Scsi_Host ref count
+ * @shost: Pointer to Scsi_Host to dec.
+ **/
+void scsi_host_put(struct Scsi_Host *shost)
+{
+ put_device(&shost->shost_gendev);
+}
+EXPORT_SYMBOL(scsi_host_put);
+
+int scsi_init_hosts(void)
+{
+ return class_register(&shost_class);
+}
+
+void scsi_exit_hosts(void)
+{
+ class_unregister(&shost_class);
+}
+
+int scsi_is_host_device(const struct device *dev)
+{
+ return dev->release == scsi_host_dev_release;
+}
+EXPORT_SYMBOL(scsi_is_host_device);
+
+/**
+ * scsi_queue_work - Queue work to the Scsi_Host workqueue.
+ * @shost: Pointer to Scsi_Host.
+ * @work: Work to queue for execution.
+ *
+ * Return value:
+ * 0 on success / != 0 for error
+ **/
+int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
+{
+ if (unlikely(!shost->work_q)) {
+ printk(KERN_ERR
+ "ERROR: Scsi host '%s' attempted to queue scsi-work, "
+ "when no workqueue created.\n", shost->hostt->name);
+ dump_stack();
+
+ return -EINVAL;
+ }
+
+ return queue_work(shost->work_q, work);
+}
+EXPORT_SYMBOL_GPL(scsi_queue_work);
+
+/**
+ * scsi_flush_work - Flush a Scsi_Host's workqueue.
+ * @shost: Pointer to Scsi_Host.
+ **/
+void scsi_flush_work(struct Scsi_Host *shost)
+{
+ if (!shost->work_q) {
+ printk(KERN_ERR
+ "ERROR: Scsi host '%s' attempted to flush scsi-work, "
+ "when no workqueue created.\n", shost->hostt->name);
+ dump_stack();
+ return;
+ }
+
+ flush_workqueue(shost->work_q);
+}
+EXPORT_SYMBOL_GPL(scsi_flush_work);