diff options
Diffstat (limited to 'drivers/scsi/hosts.c')
| -rw-r--r-- | drivers/scsi/hosts.c | 744 |
1 files changed, 744 insertions, 0 deletions
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c new file mode 100644 index 0000000000..d7f51b84f3 --- /dev/null +++ b/drivers/scsi/hosts.c @@ -0,0 +1,744 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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/scsi_cmnd.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, + .dev_groups = scsi_shost_groups, +}; + +/** + * 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); + scsi_proc_hostdir_rm(shost->hostt); + + /* + * New SCSI devices cannot be attached anymore because of the SCSI host + * state so drop the tag set refcnt. Wait until the tag set refcnt drops + * to zero because .exit_cmd_priv implementations may need the host + * pointer. + */ + kref_put(&shost->tagset_refcnt, scsi_mq_free_tags); + wait_for_completion(&shost->tagset_freed); + + 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) +{ + const 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; + } + + /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */ + shost->cmd_per_lun = min_t(int, shost->cmd_per_lun, + shost->can_queue); + + error = scsi_init_sense_cache(shost); + if (error) + 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; + + if (dma_dev->dma_mask) { + shost->max_sectors = min_t(unsigned int, shost->max_sectors, + dma_max_mapping_size(dma_dev) >> SECTOR_SHIFT); + } + + error = scsi_mq_setup_tags(shost); + if (error) + goto fail; + + kref_init(&shost->tagset_refcnt); + init_completion(&shost->tagset_freed); + + /* + * 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); + + get_device(&shost->shost_gendev); + error = device_add(&shost->shost_dev); + if (error) + goto out_del_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 = alloc_workqueue("%s", + WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND, + 1, shost->work_q_name); + + if (!shost->work_q) { + error = -EINVAL; + goto out_del_dev; + } + } + + error = scsi_sysfs_add_host(shost); + if (error) + goto out_del_dev; + + scsi_proc_host_add(shost); + scsi_autopm_put_host(shost); + return error; + + /* + * Any host allocation in this function will be freed in + * scsi_host_dev_release(). + */ + out_del_dev: + device_del(&shost->shost_dev); + out_del_gendev: + /* + * Host state is SHOST_RUNNING so we have to explicitly release + * ->shost_dev. + */ + put_device(&shost->shost_dev); + 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); + kref_put(&shost->tagset_refcnt, scsi_mq_free_tags); + 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; + + /* Wait for functions invoked through call_rcu(&scmd->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_remove_host() has been called. + * This avoids that the memory allocated for the shost_dev + * name is leaked. + */ + kfree(dev_name(&shost->shost_dev)); + } + + kfree(shost->shost_data); + + ida_free(&host_index_ida, shost->host_no); + + if (shost->shost_state != SHOST_CREATED) + 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(const struct scsi_host_template *sht, int privsize) +{ + struct Scsi_Host *shost; + int index; + + shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL); + 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_abort_list); + 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_alloc(&host_index_ida, GFP_KERNEL); + if (index < 0) { + kfree(shost); + return NULL; + } + 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->no_write_same = sht->no_write_same; + shost->host_tagset = sht->host_tagset; + shost->queuecommand_may_block = sht->queuecommand_may_block; + + 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; + + if (sht->max_segment_size) + shost->max_segment_size = sht->max_segment_size; + else + shost->max_segment_size = BLK_MAX_SEGMENT_SIZE; + + /* + * assume a 4GB boundary, if not set + */ + if (sht->dma_boundary) + shost->dma_boundary = sht->dma_boundary; + else + shost->dma_boundary = 0xffffffff; + + if (sht->virt_boundary_mask) + shost->virt_boundary_mask = sht->virt_boundary_mask; + + 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; + scsi_enable_async_suspend(&shost->shost_gendev); + + 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 = sht->shost_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)); + shost->ehandler = NULL; + goto fail; + } + + shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", + WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, + 1, shost->host_no); + if (!shost->tmf_work_q) { + shost_printk(KERN_WARNING, shost, + "failed to create tmf workq\n"); + goto fail; + } + if (scsi_proc_hostdir_add(shost->hostt) < 0) + goto fail; + return shost; + fail: + /* + * Host state is still SHOST_CREATED and that is enough to release + * ->shost_gendev. scsi_host_dev_release() will free + * dev_name(&shost->shost_dev). + */ + put_device(&shost->shost_gendev); + + return NULL; +} +EXPORT_SYMBOL(scsi_host_alloc); + +static int __scsi_host_match(struct device *dev, const void *data) +{ + struct Scsi_Host *p; + const unsigned int *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 int 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); + +static bool scsi_host_check_in_flight(struct request *rq, void *data) +{ + int *count = data; + struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); + + if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state)) + (*count)++; + + return true; +} + +/** + * scsi_host_busy - Return the host busy counter + * @shost: Pointer to Scsi_Host to inc. + **/ +int scsi_host_busy(struct Scsi_Host *shost) +{ + int cnt = 0; + + blk_mq_tagset_busy_iter(&shost->tag_set, + scsi_host_check_in_flight, &cnt); + return cnt; +} +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); + +static bool complete_all_cmds_iter(struct request *rq, void *data) +{ + struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq); + enum scsi_host_status status = *(enum scsi_host_status *)data; + + scsi_dma_unmap(scmd); + scmd->result = 0; + set_host_byte(scmd, status); + scsi_done(scmd); + return true; +} + +/** + * scsi_host_complete_all_commands - Terminate all running commands + * @shost: Scsi Host on which commands should be terminated + * @status: Status to be set for the terminated commands + * + * There is no protection against modification of the number + * of outstanding commands. It is the responsibility of the + * caller to ensure that concurrent I/O submission and/or + * completion is stopped when calling this function. + */ +void scsi_host_complete_all_commands(struct Scsi_Host *shost, + enum scsi_host_status status) +{ + blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter, + &status); +} +EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands); + +struct scsi_host_busy_iter_data { + bool (*fn)(struct scsi_cmnd *, void *); + void *priv; +}; + +static bool __scsi_host_busy_iter_fn(struct request *req, void *priv) +{ + struct scsi_host_busy_iter_data *iter_data = priv; + struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req); + + return iter_data->fn(sc, iter_data->priv); +} + +/** + * scsi_host_busy_iter - Iterate over all busy commands + * @shost: Pointer to Scsi_Host. + * @fn: Function to call on each busy command + * @priv: Data pointer passed to @fn + * + * If locking against concurrent command completions is required + * ithas to be provided by the caller + **/ +void scsi_host_busy_iter(struct Scsi_Host *shost, + bool (*fn)(struct scsi_cmnd *, void *), + void *priv) +{ + struct scsi_host_busy_iter_data iter_data = { + .fn = fn, + .priv = priv, + }; + + blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn, + &iter_data); +} +EXPORT_SYMBOL_GPL(scsi_host_busy_iter); |