linux/drivers/scsi/hosts.c
Christoph Hellwig e9c787e65c scsi: allocate scsi_cmnd structures as part of struct request
Rely on the new block layer functionality to allocate additional driver
specific data behind struct request instead of implementing it in SCSI
itѕelf.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 15:08:35 -07:00

664 lines
16 KiB
C

/*
* 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/slab.h>
#include <linux/kthread.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/transport_class.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/idr.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 DEFINE_IDA(host_index_ida);
static void scsi_host_cls_release(struct device *dev)
{
put_device(&class_to_shost(dev)->shost_gendev);
}
static struct class shost_class = {
.name = "scsi_host",
.dev_release = scsi_host_cls_release,
};
/**
* scsi_host_set_state - Take the given host through the host state model.
* @shost: scsi host to change the state of.
* @state: state to change to.
*
* Returns zero if unsuccessful or an error if the requested
* transition is illegal.
**/
int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
{
enum scsi_host_state oldstate = shost->shost_state;
if (state == oldstate)
return 0;
switch (state) {
case SHOST_CREATED:
/* There are no legal states that come back to
* created. This is the manually initialised start
* state */
goto illegal;
case SHOST_RUNNING:
switch (oldstate) {
case SHOST_CREATED:
case SHOST_RECOVERY:
break;
default:
goto illegal;
}
break;
case SHOST_RECOVERY:
switch (oldstate) {
case SHOST_RUNNING:
break;
default:
goto illegal;
}
break;
case SHOST_CANCEL:
switch (oldstate) {
case SHOST_CREATED:
case SHOST_RUNNING:
case SHOST_CANCEL_RECOVERY:
break;
default:
goto illegal;
}
break;
case SHOST_DEL:
switch (oldstate) {
case SHOST_CANCEL:
case SHOST_DEL_RECOVERY:
break;
default:
goto illegal;
}
break;
case SHOST_CANCEL_RECOVERY:
switch (oldstate) {
case SHOST_CANCEL:
case SHOST_RECOVERY:
break;
default:
goto illegal;
}
break;
case SHOST_DEL_RECOVERY:
switch (oldstate) {
case SHOST_CANCEL_RECOVERY:
break;
default:
goto illegal;
}
break;
}
shost->shost_state = state;
return 0;
illegal:
SCSI_LOG_ERROR_RECOVERY(1,
shost_printk(KERN_ERR, shost,
"Illegal host state transition"
"%s->%s\n",
scsi_host_state_name(oldstate),
scsi_host_state_name(state)));
return -EINVAL;
}
EXPORT_SYMBOL(scsi_host_set_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)
{
unsigned long flags;
mutex_lock(&shost->scan_mutex);
spin_lock_irqsave(shost->host_lock, flags);
if (scsi_host_set_state(shost, SHOST_CANCEL))
if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) {
spin_unlock_irqrestore(shost->host_lock, flags);
mutex_unlock(&shost->scan_mutex);
return;
}
spin_unlock_irqrestore(shost->host_lock, flags);
scsi_autopm_get_host(shost);
flush_workqueue(shost->tmf_work_q);
scsi_forget_host(shost);
mutex_unlock(&shost->scan_mutex);
scsi_proc_host_rm(shost);
spin_lock_irqsave(shost->host_lock, flags);
if (scsi_host_set_state(shost, SHOST_DEL))
BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
spin_unlock_irqrestore(shost->host_lock, flags);
transport_unregister_device(&shost->shost_gendev);
device_unregister(&shost->shost_dev);
device_del(&shost->shost_gendev);
}
EXPORT_SYMBOL(scsi_remove_host);
/**
* scsi_add_host_with_dma - add a scsi host with dma device
* @shost: scsi host pointer to add
* @dev: a struct device of type scsi class
* @dma_dev: dma device for the host
*
* Note: You rarely need to worry about this unless you're in a
* virtualised host environments, so use the simpler scsi_add_host()
* function instead.
*
* Return value:
* 0 on success / != 0 for error
**/
int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
struct device *dma_dev)
{
struct scsi_host_template *sht = shost->hostt;
int error = -EINVAL;
shost_printk(KERN_INFO, shost, "%s\n",
sht->info ? sht->info(shost) : sht->name);
if (!shost->can_queue) {
shost_printk(KERN_ERR, shost,
"can_queue = 0 no longer supported\n");
goto fail;
}
error = scsi_init_sense_cache(shost);
if (error)
goto fail;
if (shost_use_blk_mq(shost)) {
error = scsi_mq_setup_tags(shost);
if (error)
goto fail;
} else {
shost->bqt = blk_init_tags(shost->can_queue,
shost->hostt->tag_alloc_policy);
if (!shost->bqt) {
error = -ENOMEM;
goto fail;
}
}
if (!shost->shost_gendev.parent)
shost->shost_gendev.parent = dev ? dev : &platform_bus;
if (!dma_dev)
dma_dev = shost->shost_gendev.parent;
shost->dma_dev = dma_dev;
/*
* Increase usage count temporarily here so that calling
* scsi_autopm_put_host() will trigger runtime idle if there is
* nothing else preventing suspending the device.
*/
pm_runtime_get_noresume(&shost->shost_gendev);
pm_runtime_set_active(&shost->shost_gendev);
pm_runtime_enable(&shost->shost_gendev);
device_enable_async_suspend(&shost->shost_gendev);
error = device_add(&shost->shost_gendev);
if (error)
goto out_disable_runtime_pm;
scsi_host_set_state(shost, SHOST_RUNNING);
get_device(shost->shost_gendev.parent);
device_enable_async_suspend(&shost->shost_dev);
error = device_add(&shost->shost_dev);
if (error)
goto out_del_gendev;
get_device(&shost->shost_gendev);
if (shost->transportt->host_size) {
shost->shost_data = kzalloc(shost->transportt->host_size,
GFP_KERNEL);
if (shost->shost_data == NULL) {
error = -ENOMEM;
goto out_del_dev;
}
}
if (shost->transportt->create_work_queue) {
snprintf(shost->work_q_name, sizeof(shost->work_q_name),
"scsi_wq_%d", shost->host_no);
shost->work_q = create_singlethread_workqueue(
shost->work_q_name);
if (!shost->work_q) {
error = -EINVAL;
goto out_free_shost_data;
}
}
error = scsi_sysfs_add_host(shost);
if (error)
goto out_destroy_host;
scsi_proc_host_add(shost);
scsi_autopm_put_host(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_dev:
device_del(&shost->shost_dev);
out_del_gendev:
device_del(&shost->shost_gendev);
out_disable_runtime_pm:
device_disable_async_suspend(&shost->shost_gendev);
pm_runtime_disable(&shost->shost_gendev);
pm_runtime_set_suspended(&shost->shost_gendev);
pm_runtime_put_noidle(&shost->shost_gendev);
if (shost_use_blk_mq(shost))
scsi_mq_destroy_tags(shost);
fail:
return error;
}
EXPORT_SYMBOL(scsi_add_host_with_dma);
static void scsi_host_dev_release(struct device *dev)
{
struct Scsi_Host *shost = dev_to_shost(dev);
struct device *parent = dev->parent;
struct request_queue *q;
void *queuedata;
scsi_proc_hostdir_rm(shost->hostt);
if (shost->tmf_work_q)
destroy_workqueue(shost->tmf_work_q);
if (shost->ehandler)
kthread_stop(shost->ehandler);
if (shost->work_q)
destroy_workqueue(shost->work_q);
q = shost->uspace_req_q;
if (q) {
queuedata = q->queuedata;
blk_cleanup_queue(q);
kfree(queuedata);
}
if (shost->shost_state == SHOST_CREATED) {
/*
* Free the shost_dev device name here if scsi_host_alloc()
* and scsi_host_put() have been called but neither
* scsi_host_add() nor scsi_host_remove() has been called.
* This avoids that the memory allocated for the shost_dev
* name is leaked.
*/
kfree(dev_name(&shost->shost_dev));
}
if (shost_use_blk_mq(shost)) {
if (shost->tag_set.tags)
scsi_mq_destroy_tags(shost);
} else {
if (shost->bqt)
blk_free_tags(shost->bqt);
}
kfree(shost->shost_data);
ida_simple_remove(&host_index_ida, shost->host_no);
if (parent)
put_device(parent);
kfree(shost);
}
static int shost_eh_deadline = -1;
module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(eh_deadline,
"SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
static struct device_type scsi_host_type = {
.name = "scsi_host",
.release = scsi_host_dev_release,
};
/**
* 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;
gfp_t gfp_mask = GFP_KERNEL;
int index;
if (sht->unchecked_isa_dma && privsize)
gfp_mask |= __GFP_DMA;
shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
if (!shost)
return NULL;
shost->host_lock = &shost->default_lock;
spin_lock_init(shost->host_lock);
shost->shost_state = SHOST_CREATED;
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);
mutex_init(&shost->scan_mutex);
index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
if (index < 0)
goto fail_kfree;
shost->host_no = index;
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->sg_prot_tablesize = sht->sg_prot_tablesize;
shost->cmd_per_lun = sht->cmd_per_lun;
shost->unchecked_isa_dma = sht->unchecked_isa_dma;
shost->use_clustering = sht->use_clustering;
shost->no_write_same = sht->no_write_same;
if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
shost->eh_deadline = -1;
else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
shost_printk(KERN_WARNING, shost,
"eh_deadline %u too large, setting to %u\n",
shost_eh_deadline, INT_MAX / HZ);
shost->eh_deadline = INT_MAX;
} else
shost->eh_deadline = shost_eh_deadline * HZ;
if (sht->supported_mode == MODE_UNKNOWN)
/* means we didn't set it ... default to INITIATOR */
shost->active_mode = MODE_INITIATOR;
else
shost->active_mode = sht->supported_mode;
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;
shost->use_blk_mq = scsi_use_blk_mq;
device_initialize(&shost->shost_gendev);
dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
shost->shost_gendev.bus = &scsi_bus_type;
shost->shost_gendev.type = &scsi_host_type;
device_initialize(&shost->shost_dev);
shost->shost_dev.parent = &shost->shost_gendev;
shost->shost_dev.class = &shost_class;
dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
shost->ehandler = kthread_run(scsi_error_handler, shost,
"scsi_eh_%d", shost->host_no);
if (IS_ERR(shost->ehandler)) {
shost_printk(KERN_WARNING, shost,
"error handler thread failed to spawn, error = %ld\n",
PTR_ERR(shost->ehandler));
goto fail_index_remove;
}
shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
WQ_UNBOUND | WQ_MEM_RECLAIM,
1, shost->host_no);
if (!shost->tmf_work_q) {
shost_printk(KERN_WARNING, shost,
"failed to create tmf workq\n");
goto fail_kthread;
}
scsi_proc_hostdir_add(shost->hostt);
return shost;
fail_kthread:
kthread_stop(shost->ehandler);
fail_index_remove:
ida_simple_remove(&host_index_ida, shost->host_no);
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);
static int __scsi_host_match(struct device *dev, const void *data)
{
struct Scsi_Host *p;
const unsigned short *hostnum = data;
p = class_to_shost(dev);
return p->host_no == *hostnum;
}
/**
* 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.
*
* The caller must do a scsi_host_put() to drop the reference
* that scsi_host_get() took. The put_device() below dropped
* the reference from class_find_device().
**/
struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
{
struct device *cdev;
struct Scsi_Host *shost = NULL;
cdev = class_find_device(&shost_class, NULL, &hostnum,
__scsi_host_match);
if (cdev) {
shost = scsi_host_get(class_to_shost(cdev));
put_device(cdev);
}
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 ((shost->shost_state == SHOST_DEL) ||
!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);
ida_destroy(&host_index_ida);
}
int scsi_is_host_device(const struct device *dev)
{
return dev->type == &scsi_host_type;
}
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:
* 1 - work queued for execution
* 0 - work is already queued
* -EINVAL - work queue doesn't exist
**/
int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
{
if (unlikely(!shost->work_q)) {
shost_printk(KERN_ERR, shost,
"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) {
shost_printk(KERN_ERR, shost,
"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);