v4.19.13 snapshot.
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
new file mode 100644
index 0000000..ea4b0bb
--- /dev/null
+++ b/drivers/scsi/hosts.c
@@ -0,0 +1,644 @@
+/*
+ * 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 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 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;
+}
+
+/**
+ * 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;
+
+ scsi_proc_hostdir_rm(shost->hostt);
+
+ /* Wait for functions invoked through call_rcu(&shost->rcu, ...) */
+ rcu_barrier();
+
+ 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);
+
+ 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 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 || shost->hostt->force_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);
+
+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_busy - Return the host busy counter
+ * @shost: Pointer to Scsi_Host to inc.
+ **/
+int scsi_host_busy(struct Scsi_Host *shost)
+{
+ return atomic_read(&shost->host_busy);
+}
+EXPORT_SYMBOL(scsi_host_busy);
+
+/**
+ * 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);