| /* |
| * scsi.c Copyright (C) 1992 Drew Eckhardt |
| * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale |
| * Copyright (C) 2002, 2003 Christoph Hellwig |
| * |
| * generic mid-level SCSI driver |
| * Initial versions: Drew Eckhardt |
| * Subsequent revisions: Eric Youngdale |
| * |
| * <drew@colorado.edu> |
| * |
| * Bug correction thanks go to : |
| * Rik Faith <faith@cs.unc.edu> |
| * Tommy Thorn <tthorn> |
| * Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de> |
| * |
| * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to |
| * add scatter-gather, multiple outstanding request, and other |
| * enhancements. |
| * |
| * Native multichannel, wide scsi, /proc/scsi and hot plugging |
| * support added by Michael Neuffer <mike@i-connect.net> |
| * |
| * Added request_module("scsi_hostadapter") for kerneld: |
| * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf) |
| * Bjorn Ekwall <bj0rn@blox.se> |
| * (changed to kmod) |
| * |
| * Major improvements to the timeout, abort, and reset processing, |
| * as well as performance modifications for large queue depths by |
| * Leonard N. Zubkoff <lnz@dandelion.com> |
| * |
| * Converted cli() code to spinlocks, Ingo Molnar |
| * |
| * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli |
| * |
| * out_of_space hacks, D. Gilbert (dpg) 990608 |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/kernel.h> |
| #include <linux/timer.h> |
| #include <linux/string.h> |
| #include <linux/slab.h> |
| #include <linux/blkdev.h> |
| #include <linux/delay.h> |
| #include <linux/init.h> |
| #include <linux/completion.h> |
| #include <linux/unistd.h> |
| #include <linux/spinlock.h> |
| #include <linux/kmod.h> |
| #include <linux/interrupt.h> |
| #include <linux/notifier.h> |
| #include <linux/cpu.h> |
| #include <linux/mutex.h> |
| #include <linux/async.h> |
| #include <asm/unaligned.h> |
| |
| #include <scsi/scsi.h> |
| #include <scsi/scsi_cmnd.h> |
| #include <scsi/scsi_dbg.h> |
| #include <scsi/scsi_device.h> |
| #include <scsi/scsi_driver.h> |
| #include <scsi/scsi_eh.h> |
| #include <scsi/scsi_host.h> |
| #include <scsi/scsi_tcq.h> |
| |
| #include "scsi_priv.h" |
| #include "scsi_logging.h" |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/scsi.h> |
| |
| static void scsi_done(struct scsi_cmnd *cmd); |
| |
| /* |
| * Definitions and constants. |
| */ |
| |
| /* |
| * Note - the initial logging level can be set here to log events at boot time. |
| * After the system is up, you may enable logging via the /proc interface. |
| */ |
| unsigned int scsi_logging_level; |
| #if defined(CONFIG_SCSI_LOGGING) |
| EXPORT_SYMBOL(scsi_logging_level); |
| #endif |
| |
| /* sd, scsi core and power management need to coordinate flushing async actions */ |
| ASYNC_DOMAIN(scsi_sd_probe_domain); |
| EXPORT_SYMBOL(scsi_sd_probe_domain); |
| |
| /* NB: These are exposed through /proc/scsi/scsi and form part of the ABI. |
| * You may not alter any existing entry (although adding new ones is |
| * encouraged once assigned by ANSI/INCITS T10 |
| */ |
| static const char *const scsi_device_types[] = { |
| "Direct-Access ", |
| "Sequential-Access", |
| "Printer ", |
| "Processor ", |
| "WORM ", |
| "CD-ROM ", |
| "Scanner ", |
| "Optical Device ", |
| "Medium Changer ", |
| "Communications ", |
| "ASC IT8 ", |
| "ASC IT8 ", |
| "RAID ", |
| "Enclosure ", |
| "Direct-Access-RBC", |
| "Optical card ", |
| "Bridge controller", |
| "Object storage ", |
| "Automation/Drive ", |
| }; |
| |
| /** |
| * scsi_device_type - Return 17 char string indicating device type. |
| * @type: type number to look up |
| */ |
| |
| const char * scsi_device_type(unsigned type) |
| { |
| if (type == 0x1e) |
| return "Well-known LUN "; |
| if (type == 0x1f) |
| return "No Device "; |
| if (type >= ARRAY_SIZE(scsi_device_types)) |
| return "Unknown "; |
| return scsi_device_types[type]; |
| } |
| |
| EXPORT_SYMBOL(scsi_device_type); |
| |
| struct scsi_host_cmd_pool { |
| struct kmem_cache *cmd_slab; |
| struct kmem_cache *sense_slab; |
| unsigned int users; |
| char *cmd_name; |
| char *sense_name; |
| unsigned int slab_flags; |
| gfp_t gfp_mask; |
| }; |
| |
| static struct scsi_host_cmd_pool scsi_cmd_pool = { |
| .cmd_name = "scsi_cmd_cache", |
| .sense_name = "scsi_sense_cache", |
| .slab_flags = SLAB_HWCACHE_ALIGN, |
| }; |
| |
| static struct scsi_host_cmd_pool scsi_cmd_dma_pool = { |
| .cmd_name = "scsi_cmd_cache(DMA)", |
| .sense_name = "scsi_sense_cache(DMA)", |
| .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA, |
| .gfp_mask = __GFP_DMA, |
| }; |
| |
| static DEFINE_MUTEX(host_cmd_pool_mutex); |
| |
| /** |
| * scsi_pool_alloc_command - internal function to get a fully allocated command |
| * @pool: slab pool to allocate the command from |
| * @gfp_mask: mask for the allocation |
| * |
| * Returns a fully allocated command (with the allied sense buffer) or |
| * NULL on failure |
| */ |
| static struct scsi_cmnd * |
| scsi_pool_alloc_command(struct scsi_host_cmd_pool *pool, gfp_t gfp_mask) |
| { |
| struct scsi_cmnd *cmd; |
| |
| cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask); |
| if (!cmd) |
| return NULL; |
| |
| cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab, |
| gfp_mask | pool->gfp_mask); |
| if (!cmd->sense_buffer) { |
| kmem_cache_free(pool->cmd_slab, cmd); |
| return NULL; |
| } |
| |
| return cmd; |
| } |
| |
| /** |
| * scsi_pool_free_command - internal function to release a command |
| * @pool: slab pool to allocate the command from |
| * @cmd: command to release |
| * |
| * the command must previously have been allocated by |
| * scsi_pool_alloc_command. |
| */ |
| static void |
| scsi_pool_free_command(struct scsi_host_cmd_pool *pool, |
| struct scsi_cmnd *cmd) |
| { |
| if (cmd->prot_sdb) |
| kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb); |
| |
| kmem_cache_free(pool->sense_slab, cmd->sense_buffer); |
| kmem_cache_free(pool->cmd_slab, cmd); |
| } |
| |
| /** |
| * scsi_host_alloc_command - internal function to allocate command |
| * @shost: SCSI host whose pool to allocate from |
| * @gfp_mask: mask for the allocation |
| * |
| * Returns a fully allocated command with sense buffer and protection |
| * data buffer (where applicable) or NULL on failure |
| */ |
| static struct scsi_cmnd * |
| scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask) |
| { |
| struct scsi_cmnd *cmd; |
| |
| cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask); |
| if (!cmd) |
| return NULL; |
| |
| if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) { |
| cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask); |
| |
| if (!cmd->prot_sdb) { |
| scsi_pool_free_command(shost->cmd_pool, cmd); |
| return NULL; |
| } |
| } |
| |
| return cmd; |
| } |
| |
| /** |
| * __scsi_get_command - Allocate a struct scsi_cmnd |
| * @shost: host to transmit command |
| * @gfp_mask: allocation mask |
| * |
| * Description: allocate a struct scsi_cmd from host's slab, recycling from the |
| * host's free_list if necessary. |
| */ |
| struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) |
| { |
| struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask); |
| |
| if (unlikely(!cmd)) { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&shost->free_list_lock, flags); |
| if (likely(!list_empty(&shost->free_list))) { |
| cmd = list_entry(shost->free_list.next, |
| struct scsi_cmnd, list); |
| list_del_init(&cmd->list); |
| } |
| spin_unlock_irqrestore(&shost->free_list_lock, flags); |
| |
| if (cmd) { |
| void *buf, *prot; |
| |
| buf = cmd->sense_buffer; |
| prot = cmd->prot_sdb; |
| |
| memset(cmd, 0, sizeof(*cmd)); |
| |
| cmd->sense_buffer = buf; |
| cmd->prot_sdb = prot; |
| } |
| } |
| |
| return cmd; |
| } |
| EXPORT_SYMBOL_GPL(__scsi_get_command); |
| |
| /** |
| * scsi_get_command - Allocate and setup a scsi command block |
| * @dev: parent scsi device |
| * @gfp_mask: allocator flags |
| * |
| * Returns: The allocated scsi command structure. |
| */ |
| struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask) |
| { |
| struct scsi_cmnd *cmd = __scsi_get_command(dev->host, gfp_mask); |
| unsigned long flags; |
| |
| if (unlikely(cmd == NULL)) |
| return NULL; |
| |
| cmd->device = dev; |
| INIT_LIST_HEAD(&cmd->list); |
| INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); |
| spin_lock_irqsave(&dev->list_lock, flags); |
| list_add_tail(&cmd->list, &dev->cmd_list); |
| spin_unlock_irqrestore(&dev->list_lock, flags); |
| cmd->jiffies_at_alloc = jiffies; |
| return cmd; |
| } |
| EXPORT_SYMBOL(scsi_get_command); |
| |
| /** |
| * __scsi_put_command - Free a struct scsi_cmnd |
| * @shost: dev->host |
| * @cmd: Command to free |
| */ |
| void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd) |
| { |
| unsigned long flags; |
| |
| if (unlikely(list_empty(&shost->free_list))) { |
| spin_lock_irqsave(&shost->free_list_lock, flags); |
| if (list_empty(&shost->free_list)) { |
| list_add(&cmd->list, &shost->free_list); |
| cmd = NULL; |
| } |
| spin_unlock_irqrestore(&shost->free_list_lock, flags); |
| } |
| |
| if (likely(cmd != NULL)) |
| scsi_pool_free_command(shost->cmd_pool, cmd); |
| } |
| EXPORT_SYMBOL(__scsi_put_command); |
| |
| /** |
| * scsi_put_command - Free a scsi command block |
| * @cmd: command block to free |
| * |
| * Returns: Nothing. |
| * |
| * Notes: The command must not belong to any lists. |
| */ |
| void scsi_put_command(struct scsi_cmnd *cmd) |
| { |
| unsigned long flags; |
| |
| /* serious error if the command hasn't come from a device list */ |
| spin_lock_irqsave(&cmd->device->list_lock, flags); |
| BUG_ON(list_empty(&cmd->list)); |
| list_del_init(&cmd->list); |
| spin_unlock_irqrestore(&cmd->device->list_lock, flags); |
| |
| cancel_delayed_work(&cmd->abort_work); |
| |
| __scsi_put_command(cmd->device->host, cmd); |
| } |
| EXPORT_SYMBOL(scsi_put_command); |
| |
| static struct scsi_host_cmd_pool *scsi_get_host_cmd_pool(gfp_t gfp_mask) |
| { |
| struct scsi_host_cmd_pool *retval = NULL, *pool; |
| /* |
| * Select a command slab for this host and create it if not |
| * yet existent. |
| */ |
| mutex_lock(&host_cmd_pool_mutex); |
| pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool : |
| &scsi_cmd_pool; |
| if (!pool->users) { |
| pool->cmd_slab = kmem_cache_create(pool->cmd_name, |
| sizeof(struct scsi_cmnd), 0, |
| pool->slab_flags, NULL); |
| if (!pool->cmd_slab) |
| goto fail; |
| |
| pool->sense_slab = kmem_cache_create(pool->sense_name, |
| SCSI_SENSE_BUFFERSIZE, 0, |
| pool->slab_flags, NULL); |
| if (!pool->sense_slab) { |
| kmem_cache_destroy(pool->cmd_slab); |
| goto fail; |
| } |
| } |
| |
| pool->users++; |
| retval = pool; |
| fail: |
| mutex_unlock(&host_cmd_pool_mutex); |
| return retval; |
| } |
| |
| static void scsi_put_host_cmd_pool(gfp_t gfp_mask) |
| { |
| struct scsi_host_cmd_pool *pool; |
| |
| mutex_lock(&host_cmd_pool_mutex); |
| pool = (gfp_mask & __GFP_DMA) ? &scsi_cmd_dma_pool : |
| &scsi_cmd_pool; |
| /* |
| * This may happen if a driver has a mismatched get and put |
| * of the command pool; the driver should be implicated in |
| * the stack trace |
| */ |
| BUG_ON(pool->users == 0); |
| |
| if (!--pool->users) { |
| kmem_cache_destroy(pool->cmd_slab); |
| kmem_cache_destroy(pool->sense_slab); |
| } |
| mutex_unlock(&host_cmd_pool_mutex); |
| } |
| |
| /** |
| * scsi_allocate_command - get a fully allocated SCSI command |
| * @gfp_mask: allocation mask |
| * |
| * This function is for use outside of the normal host based pools. |
| * It allocates the relevant command and takes an additional reference |
| * on the pool it used. This function *must* be paired with |
| * scsi_free_command which also has the identical mask, otherwise the |
| * free pool counts will eventually go wrong and you'll trigger a bug. |
| * |
| * This function should *only* be used by drivers that need a static |
| * command allocation at start of day for internal functions. |
| */ |
| struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask) |
| { |
| struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask); |
| |
| if (!pool) |
| return NULL; |
| |
| return scsi_pool_alloc_command(pool, gfp_mask); |
| } |
| EXPORT_SYMBOL(scsi_allocate_command); |
| |
| /** |
| * scsi_free_command - free a command allocated by scsi_allocate_command |
| * @gfp_mask: mask used in the original allocation |
| * @cmd: command to free |
| * |
| * Note: using the original allocation mask is vital because that's |
| * what determines which command pool we use to free the command. Any |
| * mismatch will cause the system to BUG eventually. |
| */ |
| void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd) |
| { |
| struct scsi_host_cmd_pool *pool = scsi_get_host_cmd_pool(gfp_mask); |
| |
| /* |
| * this could trigger if the mask to scsi_allocate_command |
| * doesn't match this mask. Otherwise we're guaranteed that this |
| * succeeds because scsi_allocate_command must have taken a reference |
| * on the pool |
| */ |
| BUG_ON(!pool); |
| |
| scsi_pool_free_command(pool, cmd); |
| /* |
| * scsi_put_host_cmd_pool is called twice; once to release the |
| * reference we took above, and once to release the reference |
| * originally taken by scsi_allocate_command |
| */ |
| scsi_put_host_cmd_pool(gfp_mask); |
| scsi_put_host_cmd_pool(gfp_mask); |
| } |
| EXPORT_SYMBOL(scsi_free_command); |
| |
| /** |
| * scsi_setup_command_freelist - Setup the command freelist for a scsi host. |
| * @shost: host to allocate the freelist for. |
| * |
| * Description: The command freelist protects against system-wide out of memory |
| * deadlock by preallocating one SCSI command structure for each host, so the |
| * system can always write to a swap file on a device associated with that host. |
| * |
| * Returns: Nothing. |
| */ |
| int scsi_setup_command_freelist(struct Scsi_Host *shost) |
| { |
| struct scsi_cmnd *cmd; |
| const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL; |
| |
| spin_lock_init(&shost->free_list_lock); |
| INIT_LIST_HEAD(&shost->free_list); |
| |
| shost->cmd_pool = scsi_get_host_cmd_pool(gfp_mask); |
| |
| if (!shost->cmd_pool) |
| return -ENOMEM; |
| |
| /* |
| * Get one backup command for this host. |
| */ |
| cmd = scsi_host_alloc_command(shost, gfp_mask); |
| if (!cmd) { |
| scsi_put_host_cmd_pool(gfp_mask); |
| shost->cmd_pool = NULL; |
| return -ENOMEM; |
| } |
| list_add(&cmd->list, &shost->free_list); |
| return 0; |
| } |
| |
| /** |
| * scsi_destroy_command_freelist - Release the command freelist for a scsi host. |
| * @shost: host whose freelist is going to be destroyed |
| */ |
| void scsi_destroy_command_freelist(struct Scsi_Host *shost) |
| { |
| /* |
| * If cmd_pool is NULL the free list was not initialized, so |
| * do not attempt to release resources. |
| */ |
| if (!shost->cmd_pool) |
| return; |
| |
| while (!list_empty(&shost->free_list)) { |
| struct scsi_cmnd *cmd; |
| |
| cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list); |
| list_del_init(&cmd->list); |
| scsi_pool_free_command(shost->cmd_pool, cmd); |
| } |
| shost->cmd_pool = NULL; |
| scsi_put_host_cmd_pool(shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL); |
| } |
| |
| #ifdef CONFIG_SCSI_LOGGING |
| void scsi_log_send(struct scsi_cmnd *cmd) |
| { |
| unsigned int level; |
| |
| /* |
| * If ML QUEUE log level is greater than or equal to: |
| * |
| * 1: nothing (match completion) |
| * |
| * 2: log opcode + command of all commands |
| * |
| * 3: same as 2 plus dump cmd address |
| * |
| * 4: same as 3 plus dump extra junk |
| */ |
| if (unlikely(scsi_logging_level)) { |
| level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT, |
| SCSI_LOG_MLQUEUE_BITS); |
| if (level > 1) { |
| scmd_printk(KERN_INFO, cmd, "Send: "); |
| if (level > 2) |
| printk("0x%p ", cmd); |
| printk("\n"); |
| scsi_print_command(cmd); |
| if (level > 3) { |
| printk(KERN_INFO "buffer = 0x%p, bufflen = %d," |
| " queuecommand 0x%p\n", |
| scsi_sglist(cmd), scsi_bufflen(cmd), |
| cmd->device->host->hostt->queuecommand); |
| |
| } |
| } |
| } |
| } |
| |
| void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) |
| { |
| unsigned int level; |
| |
| /* |
| * If ML COMPLETE log level is greater than or equal to: |
| * |
| * 1: log disposition, result, opcode + command, and conditionally |
| * sense data for failures or non SUCCESS dispositions. |
| * |
| * 2: same as 1 but for all command completions. |
| * |
| * 3: same as 2 plus dump cmd address |
| * |
| * 4: same as 3 plus dump extra junk |
| */ |
| if (unlikely(scsi_logging_level)) { |
| level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, |
| SCSI_LOG_MLCOMPLETE_BITS); |
| if (((level > 0) && (cmd->result || disposition != SUCCESS)) || |
| (level > 1)) { |
| scmd_printk(KERN_INFO, cmd, "Done: "); |
| if (level > 2) |
| printk("0x%p ", cmd); |
| /* |
| * Dump truncated values, so we usually fit within |
| * 80 chars. |
| */ |
| switch (disposition) { |
| case SUCCESS: |
| printk("SUCCESS\n"); |
| break; |
| case NEEDS_RETRY: |
| printk("RETRY\n"); |
| break; |
| case ADD_TO_MLQUEUE: |
| printk("MLQUEUE\n"); |
| break; |
| case FAILED: |
| printk("FAILED\n"); |
| break; |
| case TIMEOUT_ERROR: |
| /* |
| * If called via scsi_times_out. |
| */ |
| printk("TIMEOUT\n"); |
| break; |
| default: |
| printk("UNKNOWN\n"); |
| } |
| scsi_print_result(cmd); |
| scsi_print_command(cmd); |
| if (status_byte(cmd->result) & CHECK_CONDITION) |
| scsi_print_sense("", cmd); |
| if (level > 3) |
| scmd_printk(KERN_INFO, cmd, |
| "scsi host busy %d failed %d\n", |
| cmd->device->host->host_busy, |
| cmd->device->host->host_failed); |
| } |
| } |
| } |
| #endif |
| |
| /** |
| * scsi_cmd_get_serial - Assign a serial number to a command |
| * @host: the scsi host |
| * @cmd: command to assign serial number to |
| * |
| * Description: a serial number identifies a request for error recovery |
| * and debugging purposes. Protected by the Host_Lock of host. |
| */ |
| void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd) |
| { |
| cmd->serial_number = host->cmd_serial_number++; |
| if (cmd->serial_number == 0) |
| cmd->serial_number = host->cmd_serial_number++; |
| } |
| EXPORT_SYMBOL(scsi_cmd_get_serial); |
| |
| /** |
| * scsi_dispatch_command - Dispatch a command to the low-level driver. |
| * @cmd: command block we are dispatching. |
| * |
| * Return: nonzero return request was rejected and device's queue needs to be |
| * plugged. |
| */ |
| int scsi_dispatch_cmd(struct scsi_cmnd *cmd) |
| { |
| struct Scsi_Host *host = cmd->device->host; |
| int rtn = 0; |
| |
| atomic_inc(&cmd->device->iorequest_cnt); |
| |
| /* check if the device is still usable */ |
| if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { |
| /* in SDEV_DEL we error all commands. DID_NO_CONNECT |
| * returns an immediate error upwards, and signals |
| * that the device is no longer present */ |
| cmd->result = DID_NO_CONNECT << 16; |
| scsi_done(cmd); |
| /* return 0 (because the command has been processed) */ |
| goto out; |
| } |
| |
| /* Check to see if the scsi lld made this device blocked. */ |
| if (unlikely(scsi_device_blocked(cmd->device))) { |
| /* |
| * in blocked state, the command is just put back on |
| * the device queue. The suspend state has already |
| * blocked the queue so future requests should not |
| * occur until the device transitions out of the |
| * suspend state. |
| */ |
| |
| scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); |
| |
| SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n")); |
| |
| /* |
| * NOTE: rtn is still zero here because we don't need the |
| * queue to be plugged on return (it's already stopped) |
| */ |
| goto out; |
| } |
| |
| /* |
| * If SCSI-2 or lower, store the LUN value in cmnd. |
| */ |
| if (cmd->device->scsi_level <= SCSI_2 && |
| cmd->device->scsi_level != SCSI_UNKNOWN) { |
| cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | |
| (cmd->device->lun << 5 & 0xe0); |
| } |
| |
| scsi_log_send(cmd); |
| |
| /* |
| * Before we queue this command, check if the command |
| * length exceeds what the host adapter can handle. |
| */ |
| if (cmd->cmd_len > cmd->device->host->max_cmd_len) { |
| SCSI_LOG_MLQUEUE(3, |
| printk("queuecommand : command too long. " |
| "cdb_size=%d host->max_cmd_len=%d\n", |
| cmd->cmd_len, cmd->device->host->max_cmd_len)); |
| cmd->result = (DID_ABORT << 16); |
| |
| scsi_done(cmd); |
| goto out; |
| } |
| |
| if (unlikely(host->shost_state == SHOST_DEL)) { |
| cmd->result = (DID_NO_CONNECT << 16); |
| scsi_done(cmd); |
| } else { |
| trace_scsi_dispatch_cmd_start(cmd); |
| cmd->scsi_done = scsi_done; |
| rtn = host->hostt->queuecommand(host, cmd); |
| } |
| |
| if (rtn) { |
| trace_scsi_dispatch_cmd_error(cmd, rtn); |
| if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && |
| rtn != SCSI_MLQUEUE_TARGET_BUSY) |
| rtn = SCSI_MLQUEUE_HOST_BUSY; |
| |
| scsi_queue_insert(cmd, rtn); |
| |
| SCSI_LOG_MLQUEUE(3, |
| printk("queuecommand : request rejected\n")); |
| } |
| |
| out: |
| SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n")); |
| return rtn; |
| } |
| |
| /** |
| * scsi_done - Invoke completion on finished SCSI command. |
| * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives |
| * ownership back to SCSI Core -- i.e. the LLDD has finished with it. |
| * |
| * Description: This function is the mid-level's (SCSI Core) interrupt routine, |
| * which regains ownership of the SCSI command (de facto) from a LLDD, and |
| * calls blk_complete_request() for further processing. |
| * |
| * This function is interrupt context safe. |
| */ |
| static void scsi_done(struct scsi_cmnd *cmd) |
| { |
| trace_scsi_dispatch_cmd_done(cmd); |
| blk_complete_request(cmd->request); |
| } |
| |
| /** |
| * scsi_finish_command - cleanup and pass command back to upper layer |
| * @cmd: the command |
| * |
| * Description: Pass command off to upper layer for finishing of I/O |
| * request, waking processes that are waiting on results, |
| * etc. |
| */ |
| void scsi_finish_command(struct scsi_cmnd *cmd) |
| { |
| struct scsi_device *sdev = cmd->device; |
| struct scsi_target *starget = scsi_target(sdev); |
| struct Scsi_Host *shost = sdev->host; |
| struct scsi_driver *drv; |
| unsigned int good_bytes; |
| |
| scsi_device_unbusy(sdev); |
| |
| /* |
| * Clear the flags which say that the device/host is no longer |
| * capable of accepting new commands. These are set in scsi_queue.c |
| * for both the queue full condition on a device, and for a |
| * host full condition on the host. |
| * |
| * XXX(hch): What about locking? |
| */ |
| shost->host_blocked = 0; |
| starget->target_blocked = 0; |
| sdev->device_blocked = 0; |
| |
| /* |
| * If we have valid sense information, then some kind of recovery |
| * must have taken place. Make a note of this. |
| */ |
| if (SCSI_SENSE_VALID(cmd)) |
| cmd->result |= (DRIVER_SENSE << 24); |
| |
| SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev, |
| "Notifying upper driver of completion " |
| "(result %x)\n", cmd->result)); |
| |
| good_bytes = scsi_bufflen(cmd); |
| if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) { |
| int old_good_bytes = good_bytes; |
| drv = scsi_cmd_to_driver(cmd); |
| if (drv->done) |
| good_bytes = drv->done(cmd); |
| /* |
| * USB may not give sense identifying bad sector and |
| * simply return a residue instead, so subtract off the |
| * residue if drv->done() error processing indicates no |
| * change to the completion length. |
| */ |
| if (good_bytes == old_good_bytes) |
| good_bytes -= scsi_get_resid(cmd); |
| } |
| scsi_io_completion(cmd, good_bytes); |
| } |
| EXPORT_SYMBOL(scsi_finish_command); |
| |
| /** |
| * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth |
| * @sdev: SCSI Device in question |
| * @tagged: Do we use tagged queueing (non-0) or do we treat |
| * this device as an untagged device (0) |
| * @tags: Number of tags allowed if tagged queueing enabled, |
| * or number of commands the low level driver can |
| * queue up in non-tagged mode (as per cmd_per_lun). |
| * |
| * Returns: Nothing |
| * |
| * Lock Status: None held on entry |
| * |
| * Notes: Low level drivers may call this at any time and we will do |
| * the right thing depending on whether or not the device is |
| * currently active and whether or not it even has the |
| * command blocks built yet. |
| */ |
| void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags) |
| { |
| unsigned long flags; |
| |
| /* |
| * refuse to set tagged depth to an unworkable size |
| */ |
| if (tags <= 0) |
| return; |
| |
| spin_lock_irqsave(sdev->request_queue->queue_lock, flags); |
| |
| /* |
| * Check to see if the queue is managed by the block layer. |
| * If it is, and we fail to adjust the depth, exit. |
| * |
| * Do not resize the tag map if it is a host wide share bqt, |
| * because the size should be the hosts's can_queue. If there |
| * is more IO than the LLD's can_queue (so there are not enuogh |
| * tags) request_fn's host queue ready check will handle it. |
| */ |
| if (!sdev->host->bqt) { |
| if (blk_queue_tagged(sdev->request_queue) && |
| blk_queue_resize_tags(sdev->request_queue, tags) != 0) |
| goto out; |
| } |
| |
| sdev->queue_depth = tags; |
| switch (tagged) { |
| case MSG_ORDERED_TAG: |
| sdev->ordered_tags = 1; |
| sdev->simple_tags = 1; |
| break; |
| case MSG_SIMPLE_TAG: |
| sdev->ordered_tags = 0; |
| sdev->simple_tags = 1; |
| break; |
| default: |
| sdev_printk(KERN_WARNING, sdev, |
| "scsi_adjust_queue_depth, bad queue type, " |
| "disabled\n"); |
| case 0: |
| sdev->ordered_tags = sdev->simple_tags = 0; |
| sdev->queue_depth = tags; |
| break; |
| } |
| out: |
| spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); |
| } |
| EXPORT_SYMBOL(scsi_adjust_queue_depth); |
| |
| /** |
| * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth |
| * @sdev: SCSI Device in question |
| * @depth: Current number of outstanding SCSI commands on this device, |
| * not counting the one returned as QUEUE_FULL. |
| * |
| * Description: This function will track successive QUEUE_FULL events on a |
| * specific SCSI device to determine if and when there is a |
| * need to adjust the queue depth on the device. |
| * |
| * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth, |
| * -1 - Drop back to untagged operation using host->cmd_per_lun |
| * as the untagged command depth |
| * |
| * Lock Status: None held on entry |
| * |
| * Notes: Low level drivers may call this at any time and we will do |
| * "The Right Thing." We are interrupt context safe. |
| */ |
| int scsi_track_queue_full(struct scsi_device *sdev, int depth) |
| { |
| |
| /* |
| * Don't let QUEUE_FULLs on the same |
| * jiffies count, they could all be from |
| * same event. |
| */ |
| if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4)) |
| return 0; |
| |
| sdev->last_queue_full_time = jiffies; |
| if (sdev->last_queue_full_depth != depth) { |
| sdev->last_queue_full_count = 1; |
| sdev->last_queue_full_depth = depth; |
| } else { |
| sdev->last_queue_full_count++; |
| } |
| |
| if (sdev->last_queue_full_count <= 10) |
| return 0; |
| if (sdev->last_queue_full_depth < 8) { |
| /* Drop back to untagged */ |
| scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); |
| return -1; |
| } |
| |
| if (sdev->ordered_tags) |
| scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth); |
| else |
| scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth); |
| return depth; |
| } |
| EXPORT_SYMBOL(scsi_track_queue_full); |
| |
| /** |
| * scsi_vpd_inquiry - Request a device provide us with a VPD page |
| * @sdev: The device to ask |
| * @buffer: Where to put the result |
| * @page: Which Vital Product Data to return |
| * @len: The length of the buffer |
| * |
| * This is an internal helper function. You probably want to use |
| * scsi_get_vpd_page instead. |
| * |
| * Returns size of the vpd page on success or a negative error number. |
| */ |
| static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer, |
| u8 page, unsigned len) |
| { |
| int result; |
| unsigned char cmd[16]; |
| |
| if (len < 4) |
| return -EINVAL; |
| |
| cmd[0] = INQUIRY; |
| cmd[1] = 1; /* EVPD */ |
| cmd[2] = page; |
| cmd[3] = len >> 8; |
| cmd[4] = len & 0xff; |
| cmd[5] = 0; /* Control byte */ |
| |
| /* |
| * I'm not convinced we need to try quite this hard to get VPD, but |
| * all the existing users tried this hard. |
| */ |
| result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, |
| len, NULL, 30 * HZ, 3, NULL); |
| if (result) |
| return -EIO; |
| |
| /* Sanity check that we got the page back that we asked for */ |
| if (buffer[1] != page) |
| return -EIO; |
| |
| return get_unaligned_be16(&buffer[2]) + 4; |
| } |
| |
| /** |
| * scsi_get_vpd_page - Get Vital Product Data from a SCSI device |
| * @sdev: The device to ask |
| * @page: Which Vital Product Data to return |
| * @buf: where to store the VPD |
| * @buf_len: number of bytes in the VPD buffer area |
| * |
| * SCSI devices may optionally supply Vital Product Data. Each 'page' |
| * of VPD is defined in the appropriate SCSI document (eg SPC, SBC). |
| * If the device supports this VPD page, this routine returns a pointer |
| * to a buffer containing the data from that page. The caller is |
| * responsible for calling kfree() on this pointer when it is no longer |
| * needed. If we cannot retrieve the VPD page this routine returns %NULL. |
| */ |
| int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf, |
| int buf_len) |
| { |
| int i, result; |
| |
| if (sdev->skip_vpd_pages) |
| goto fail; |
| |
| /* Ask for all the pages supported by this device */ |
| result = scsi_vpd_inquiry(sdev, buf, 0, buf_len); |
| if (result < 4) |
| goto fail; |
| |
| /* If the user actually wanted this page, we can skip the rest */ |
| if (page == 0) |
| return 0; |
| |
| for (i = 4; i < min(result, buf_len); i++) |
| if (buf[i] == page) |
| goto found; |
| |
| if (i < result && i >= buf_len) |
| /* ran off the end of the buffer, give us benefit of doubt */ |
| goto found; |
| /* The device claims it doesn't support the requested page */ |
| goto fail; |
| |
| found: |
| result = scsi_vpd_inquiry(sdev, buf, page, buf_len); |
| if (result < 0) |
| goto fail; |
| |
| return 0; |
| |
| fail: |
| return -EINVAL; |
| } |
| EXPORT_SYMBOL_GPL(scsi_get_vpd_page); |
| |
| /** |
| * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure |
| * @sdev: The device to ask |
| * |
| * Attach the 'Device Identification' VPD page (0x83) and the |
| * 'Unit Serial Number' VPD page (0x80) to a SCSI device |
| * structure. This information can be used to identify the device |
| * uniquely. |
| */ |
| void scsi_attach_vpd(struct scsi_device *sdev) |
| { |
| int result, i; |
| int vpd_len = SCSI_VPD_PG_LEN; |
| int pg80_supported = 0; |
| int pg83_supported = 0; |
| unsigned char *vpd_buf; |
| |
| if (sdev->skip_vpd_pages) |
| return; |
| retry_pg0: |
| vpd_buf = kmalloc(vpd_len, GFP_KERNEL); |
| if (!vpd_buf) |
| return; |
| |
| /* Ask for all the pages supported by this device */ |
| result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len); |
| if (result < 0) { |
| kfree(vpd_buf); |
| return; |
| } |
| if (result > vpd_len) { |
| vpd_len = result; |
| kfree(vpd_buf); |
| goto retry_pg0; |
| } |
| |
| for (i = 4; i < result; i++) { |
| if (vpd_buf[i] == 0x80) |
| pg80_supported = 1; |
| if (vpd_buf[i] == 0x83) |
| pg83_supported = 1; |
| } |
| kfree(vpd_buf); |
| vpd_len = SCSI_VPD_PG_LEN; |
| |
| if (pg80_supported) { |
| retry_pg80: |
| vpd_buf = kmalloc(vpd_len, GFP_KERNEL); |
| if (!vpd_buf) |
| return; |
| |
| result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len); |
| if (result < 0) { |
| kfree(vpd_buf); |
| return; |
| } |
| if (result > vpd_len) { |
| vpd_len = result; |
| kfree(vpd_buf); |
| goto retry_pg80; |
| } |
| sdev->vpd_pg80_len = result; |
| sdev->vpd_pg80 = vpd_buf; |
| vpd_len = SCSI_VPD_PG_LEN; |
| } |
| |
| if (pg83_supported) { |
| retry_pg83: |
| vpd_buf = kmalloc(vpd_len, GFP_KERNEL); |
| if (!vpd_buf) |
| return; |
| |
| result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len); |
| if (result < 0) { |
| kfree(vpd_buf); |
| return; |
| } |
| if (result > vpd_len) { |
| vpd_len = result; |
| kfree(vpd_buf); |
| goto retry_pg83; |
| } |
| sdev->vpd_pg83_len = result; |
| sdev->vpd_pg83 = vpd_buf; |
| } |
| } |
| |
| /** |
| * scsi_report_opcode - Find out if a given command opcode is supported |
| * @sdev: scsi device to query |
| * @buffer: scratch buffer (must be at least 20 bytes long) |
| * @len: length of buffer |
| * @opcode: opcode for command to look up |
| * |
| * Uses the REPORT SUPPORTED OPERATION CODES to look up the given |
| * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is |
| * unsupported and 1 if the device claims to support the command. |
| */ |
| int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer, |
| unsigned int len, unsigned char opcode) |
| { |
| unsigned char cmd[16]; |
| struct scsi_sense_hdr sshdr; |
| int result; |
| |
| if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3) |
| return -EINVAL; |
| |
| memset(cmd, 0, 16); |
| cmd[0] = MAINTENANCE_IN; |
| cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES; |
| cmd[2] = 1; /* One command format */ |
| cmd[3] = opcode; |
| put_unaligned_be32(len, &cmd[6]); |
| memset(buffer, 0, len); |
| |
| result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
| &sshdr, 30 * HZ, 3, NULL); |
| |
| if (result && scsi_sense_valid(&sshdr) && |
| sshdr.sense_key == ILLEGAL_REQUEST && |
| (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00) |
| return -EINVAL; |
| |
| if ((buffer[1] & 3) == 3) /* Command supported */ |
| return 1; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(scsi_report_opcode); |
| |
| /** |
| * scsi_device_get - get an additional reference to a scsi_device |
| * @sdev: device to get a reference to |
| * |
| * Description: Gets a reference to the scsi_device and increments the use count |
| * of the underlying LLDD module. You must hold host_lock of the |
| * parent Scsi_Host or already have a reference when calling this. |
| */ |
| int scsi_device_get(struct scsi_device *sdev) |
| { |
| if (sdev->sdev_state == SDEV_DEL) |
| return -ENXIO; |
| if (!get_device(&sdev->sdev_gendev)) |
| return -ENXIO; |
| /* We can fail this if we're doing SCSI operations |
| * from module exit (like cache flush) */ |
| try_module_get(sdev->host->hostt->module); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(scsi_device_get); |
| |
| /** |
| * scsi_device_put - release a reference to a scsi_device |
| * @sdev: device to release a reference on. |
| * |
| * Description: Release a reference to the scsi_device and decrements the use |
| * count of the underlying LLDD module. The device is freed once the last |
| * user vanishes. |
| */ |
| void scsi_device_put(struct scsi_device *sdev) |
| { |
| #ifdef CONFIG_MODULE_UNLOAD |
| struct module *module = sdev->host->hostt->module; |
| |
| /* The module refcount will be zero if scsi_device_get() |
| * was called from a module removal routine */ |
| if (module && module_refcount(module) != 0) |
| module_put(module); |
| #endif |
| put_device(&sdev->sdev_gendev); |
| } |
| EXPORT_SYMBOL(scsi_device_put); |
| |
| /* helper for shost_for_each_device, see that for documentation */ |
| struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, |
| struct scsi_device *prev) |
| { |
| struct list_head *list = (prev ? &prev->siblings : &shost->__devices); |
| struct scsi_device *next = NULL; |
| unsigned long flags; |
| |
| spin_lock_irqsave(shost->host_lock, flags); |
| while (list->next != &shost->__devices) { |
| next = list_entry(list->next, struct scsi_device, siblings); |
| /* skip devices that we can't get a reference to */ |
| if (!scsi_device_get(next)) |
| break; |
| next = NULL; |
| list = list->next; |
| } |
| spin_unlock_irqrestore(shost->host_lock, flags); |
| |
| if (prev) |
| scsi_device_put(prev); |
| return next; |
| } |
| EXPORT_SYMBOL(__scsi_iterate_devices); |
| |
| /** |
| * starget_for_each_device - helper to walk all devices of a target |
| * @starget: target whose devices we want to iterate over. |
| * @data: Opaque passed to each function call. |
| * @fn: Function to call on each device |
| * |
| * This traverses over each device of @starget. The devices have |
| * a reference that must be released by scsi_host_put when breaking |
| * out of the loop. |
| */ |
| void starget_for_each_device(struct scsi_target *starget, void *data, |
| void (*fn)(struct scsi_device *, void *)) |
| { |
| struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); |
| struct scsi_device *sdev; |
| |
| shost_for_each_device(sdev, shost) { |
| if ((sdev->channel == starget->channel) && |
| (sdev->id == starget->id)) |
| fn(sdev, data); |
| } |
| } |
| EXPORT_SYMBOL(starget_for_each_device); |
| |
| /** |
| * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED) |
| * @starget: target whose devices we want to iterate over. |
| * @data: parameter for callback @fn() |
| * @fn: callback function that is invoked for each device |
| * |
| * This traverses over each device of @starget. It does _not_ |
| * take a reference on the scsi_device, so the whole loop must be |
| * protected by shost->host_lock. |
| * |
| * Note: The only reason why drivers would want to use this is because |
| * they need to access the device list in irq context. Otherwise you |
| * really want to use starget_for_each_device instead. |
| **/ |
| void __starget_for_each_device(struct scsi_target *starget, void *data, |
| void (*fn)(struct scsi_device *, void *)) |
| { |
| struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); |
| struct scsi_device *sdev; |
| |
| __shost_for_each_device(sdev, shost) { |
| if ((sdev->channel == starget->channel) && |
| (sdev->id == starget->id)) |
| fn(sdev, data); |
| } |
| } |
| EXPORT_SYMBOL(__starget_for_each_device); |
| |
| /** |
| * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) |
| * @starget: SCSI target pointer |
| * @lun: SCSI Logical Unit Number |
| * |
| * Description: Looks up the scsi_device with the specified @lun for a given |
| * @starget. The returned scsi_device does not have an additional |
| * reference. You must hold the host's host_lock over this call and |
| * any access to the returned scsi_device. A scsi_device in state |
| * SDEV_DEL is skipped. |
| * |
| * Note: The only reason why drivers should use this is because |
| * they need to access the device list in irq context. Otherwise you |
| * really want to use scsi_device_lookup_by_target instead. |
| **/ |
| struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, |
| uint lun) |
| { |
| struct scsi_device *sdev; |
| |
| list_for_each_entry(sdev, &starget->devices, same_target_siblings) { |
| if (sdev->sdev_state == SDEV_DEL) |
| continue; |
| if (sdev->lun ==lun) |
| return sdev; |
| } |
| |
| return NULL; |
| } |
| EXPORT_SYMBOL(__scsi_device_lookup_by_target); |
| |
| /** |
| * scsi_device_lookup_by_target - find a device given the target |
| * @starget: SCSI target pointer |
| * @lun: SCSI Logical Unit Number |
| * |
| * Description: Looks up the scsi_device with the specified @lun for a given |
| * @starget. The returned scsi_device has an additional reference that |
| * needs to be released with scsi_device_put once you're done with it. |
| **/ |
| struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, |
| uint lun) |
| { |
| struct scsi_device *sdev; |
| struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); |
| unsigned long flags; |
| |
| spin_lock_irqsave(shost->host_lock, flags); |
| sdev = __scsi_device_lookup_by_target(starget, lun); |
| if (sdev && scsi_device_get(sdev)) |
| sdev = NULL; |
| spin_unlock_irqrestore(shost->host_lock, flags); |
| |
| return sdev; |
| } |
| EXPORT_SYMBOL(scsi_device_lookup_by_target); |
| |
| /** |
| * __scsi_device_lookup - find a device given the host (UNLOCKED) |
| * @shost: SCSI host pointer |
| * @channel: SCSI channel (zero if only one channel) |
| * @id: SCSI target number (physical unit number) |
| * @lun: SCSI Logical Unit Number |
| * |
| * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
| * for a given host. The returned scsi_device does not have an additional |
| * reference. You must hold the host's host_lock over this call and any access |
| * to the returned scsi_device. |
| * |
| * Note: The only reason why drivers would want to use this is because |
| * they need to access the device list in irq context. Otherwise you |
| * really want to use scsi_device_lookup instead. |
| **/ |
| struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, |
| uint channel, uint id, uint lun) |
| { |
| struct scsi_device *sdev; |
| |
| list_for_each_entry(sdev, &shost->__devices, siblings) { |
| if (sdev->channel == channel && sdev->id == id && |
| sdev->lun ==lun) |
| return sdev; |
| } |
| |
| return NULL; |
| } |
| EXPORT_SYMBOL(__scsi_device_lookup); |
| |
| /** |
| * scsi_device_lookup - find a device given the host |
| * @shost: SCSI host pointer |
| * @channel: SCSI channel (zero if only one channel) |
| * @id: SCSI target number (physical unit number) |
| * @lun: SCSI Logical Unit Number |
| * |
| * Description: Looks up the scsi_device with the specified @channel, @id, @lun |
| * for a given host. The returned scsi_device has an additional reference that |
| * needs to be released with scsi_device_put once you're done with it. |
| **/ |
| struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, |
| uint channel, uint id, uint lun) |
| { |
| struct scsi_device *sdev; |
| unsigned long flags; |
| |
| spin_lock_irqsave(shost->host_lock, flags); |
| sdev = __scsi_device_lookup(shost, channel, id, lun); |
| if (sdev && scsi_device_get(sdev)) |
| sdev = NULL; |
| spin_unlock_irqrestore(shost->host_lock, flags); |
| |
| return sdev; |
| } |
| EXPORT_SYMBOL(scsi_device_lookup); |
| |
| MODULE_DESCRIPTION("SCSI core"); |
| MODULE_LICENSE("GPL"); |
| |
| module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); |
| MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); |
| |
| static int __init init_scsi(void) |
| { |
| int error; |
| |
| error = scsi_init_queue(); |
| if (error) |
| return error; |
| error = scsi_init_procfs(); |
| if (error) |
| goto cleanup_queue; |
| error = scsi_init_devinfo(); |
| if (error) |
| goto cleanup_procfs; |
| error = scsi_init_hosts(); |
| if (error) |
| goto cleanup_devlist; |
| error = scsi_init_sysctl(); |
| if (error) |
| goto cleanup_hosts; |
| error = scsi_sysfs_register(); |
| if (error) |
| goto cleanup_sysctl; |
| |
| scsi_netlink_init(); |
| |
| printk(KERN_NOTICE "SCSI subsystem initialized\n"); |
| return 0; |
| |
| cleanup_sysctl: |
| scsi_exit_sysctl(); |
| cleanup_hosts: |
| scsi_exit_hosts(); |
| cleanup_devlist: |
| scsi_exit_devinfo(); |
| cleanup_procfs: |
| scsi_exit_procfs(); |
| cleanup_queue: |
| scsi_exit_queue(); |
| printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", |
| -error); |
| return error; |
| } |
| |
| static void __exit exit_scsi(void) |
| { |
| scsi_netlink_exit(); |
| scsi_sysfs_unregister(); |
| scsi_exit_sysctl(); |
| scsi_exit_hosts(); |
| scsi_exit_devinfo(); |
| scsi_exit_procfs(); |
| scsi_exit_queue(); |
| async_unregister_domain(&scsi_sd_probe_domain); |
| } |
| |
| subsys_initcall(init_scsi); |
| module_exit(exit_scsi); |