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/*
* 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 <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_transport.h>
#include "scsi_priv.h"
#include "scsi_logging.h"
static atomic_t scsi_host_next_hn = ATOMIC_INIT(0); /* host_no for next new host */
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;
}
if (shost_use_blk_mq(shost)) {
error = scsi_mq_setup_tags(shost);
if (error)
goto fail;
}
/*
* Note that we allocate the freelist even for the MQ case for now,
* as we need a command set aside for scsi_reset_provider. Having
* the full host freelist and one command available for that is a
* little heavy-handed, but avoids introducing a special allocator
* just for this. Eventually the structure of scsi_reset_provider
* will need a major overhaul.
*/
error = scsi_setup_command_freelist(shost);
if (error)
goto out_destroy_tags;
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;
error = device_add(&shost->shost_gendev);
if (error)
goto out_destroy_freelist;
pm_runtime_set_active(&shost->shost_gendev);
pm_runtime_enable(&shost->shost_gendev);
device_enable_async_suspend(&shost->shost_gendev);
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_hos
|