/* * 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 * * * * Bug correction thanks go to : * Rik Faith * Tommy Thorn * Thomas Wuensche * * 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 * * Added request_module("scsi_hostadapter") for kerneld: * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf) * Bjorn Ekwall * (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 * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "scsi_priv.h" #include "scsi_logging.h" #define CREATE_TRACE_POINTS #include /* * 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); /* * Separate domain (from scsi_sd_probe_domain) to maximize the benefit of * asynchronous system resume operations. It is marked 'exclusive' to avoid * being included in the async_synchronize_full() that is invoked by * dpm_resume() */ ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain); EXPORT_SYMBOL(scsi_sd_pm_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 ", "Security Manager ", "Direct-Access-ZBC", }; /** * 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_host_free_command - internal function to release a command * @shost: host to free the command for * @cmd: command to release * * the command must previously have been allocated by * scsi_host_alloc_command. */ static void scsi_host_free_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd) { struct scsi_host_cmd_pool *pool = shost->cmd_pool; 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_host_cmd_pool *pool = shost->cmd_pool; struct scsi_cmnd *cmd; cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask); if (!cmd) goto fail; cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab, gfp_mask | pool->gfp_mask); if (!cmd->sense_buffer) goto fail_free_cmd; 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) goto fail_free_sense; } return cmd; fail_free_sense: kmem_cache_free(pool->sense_slab, cmd->sense_buffer); fail_free_cmd: kmem_cache_free(pool->cmd_slab, cmd); fail: return NULL; } /** * __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. */ static 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; } /** * 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; } /** * __scsi_put_command - Free a struct scsi_cmnd * @shost: dev->host * @cmd: Command to free */ static 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_host_free_command(shost, cmd); } /** * 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); BUG_ON(delayed_work_pending(&cmd->abort_work)); __scsi_put_command(cmd->device->host, cmd); } static struct scsi_host_cmd_pool * scsi_find_host_cmd_pool(struct Scsi_Host *shost) { if (shost->hostt->cmd_size) return shost->hostt->cmd_pool; if (shost->unchecked_isa_dma) return &scsi_cmd_dma_pool; return &scsi_cmd_pool; } static void scsi_free_host_cmd_pool(struct scsi_host_cmd_pool *pool) { kfree(pool->sense_name); kfree(pool->cmd_name); kfree(pool); } static struct scsi_host_cmd_pool * scsi_alloc_host_cmd_pool(struct Scsi_Host *shost) { struct scsi_host_template *hostt = shost->hostt; struct scsi_host_cmd_pool *pool; pool = kzalloc(sizeof(*pool), GFP_KERNEL); if (!pool) return NULL; pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->proc_name); pool->sense_name = kasprintf(GFP_KERNEL, "%s_sense", hostt->proc_name); if (!pool->cmd_name || !pool->sense_name) { scsi_free_host_cmd_pool(pool); return NULL; } pool->slab_flags = SLAB_HWCACHE_ALIGN; if (shost->unchecked_isa_dma) { pool->slab_flags |= SLAB_CACHE_DMA; pool->gfp_mask = __GFP_DMA; } if (hostt->cmd_size) hostt->cmd_pool = pool; return pool; } static struct scsi_host_cmd_pool * scsi_get_host_cmd_pool(struct Scsi_Host *shost) { struct scsi_host_template *hostt = shost->hostt; struct scsi_host_cmd_pool *retval = NULL, *pool; size_t cmd_size = sizeof(struct scsi_cmnd) + hostt->cmd_size; /* * Select a command slab for this host and create it if not * yet existent. */ mutex_lock(&host_cmd_pool_mutex); pool = scsi_find_host_cmd_pool(shost); if (!pool) { pool = scsi_alloc_host_cmd_pool(shost); if (!pool) goto out; } if (!pool->users) { pool->cmd_slab = kmem_cache_create(pool->cmd_name, cmd_size, 0, pool->slab_flags, NULL); if (!pool->cmd_slab) goto out_free_pool; pool->sense_slab = kmem_cache_create(pool->sense_name, SCSI_SENSE_BUFFERSIZE, 0, pool->slab_flags, NULL); if (!pool->sense_slab) goto out_free_slab; } pool->users++; retval = pool; out: mutex_unlock(&host_cmd_pool_mutex); return retval; out_free_slab: kmem_cache_destroy(pool->cmd_slab); out_free_pool: if (hostt->cmd_size) { scsi_free_host_cmd_pool(pool); hostt->cmd_pool = NULL; } goto out; } static void scsi_put_host_cmd_pool(struct Scsi_Host *shost) { struct scsi_host_template *hostt = shost->hostt; struct scsi_host_cmd_pool *pool; mutex_lock(&host_cmd_pool_mutex); pool = scsi_find_host_cmd_pool(shost); /* * 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); if (hostt->cmd_size) { scsi_free_host_cmd_pool(pool); hostt->cmd_pool = NULL; } } mutex_unlock(&host_cmd_pool_mutex); } /** * 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) { const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL; struct scsi_cmnd *cmd; spin_lock_init(&shost->free_list_lock); INIT_LIST_HEAD(&shost->free_list); shost->cmd_pool = scsi_get_host_cmd_pool(shost); 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(shost); 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_host_free_command(shost, cmd); } shost->cmd_pool = NULL; scsi_put_host_cmd_pool(shost); } #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", atomic_read(&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; goto done; } /* 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_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, "queuecommand : device blocked\n")); return SCSI_MLQUEUE_DEVICE_BUSY; } /* Store the LUN value in cmnd, if needed. */ if (cmd->device->lun_in_cdb) 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, scmd_printk(KERN_INFO, cmd, "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); goto done; } if (unlikely(host->shost_state == SHOST_DEL)) { cmd->result = (DID_NO_CONNECT << 16); goto done; } trace_scsi_dispatch_cmd_start(cmd); 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_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, "queuecommand : request rejected\n")); } return rtn; done: cmd->scsi_done(cmd); return 0; } /** * 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 that say that the device/target/host is no longer * capable of accepting new commands. */ if (atomic_read(&shost->host_blocked)) atomic_set(&shost->host_blocked, 0); if (atomic_read(&starget->target_blocked)) atomic_set(&starget->target_blocked, 0); if (atomic_read(&sdev->device_blocked)) atomic_set(&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); } /** * 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 (!shost_use_blk_mq(sdev->host) && !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 0: sdev->ordered_tags = 0; sdev->simple_tags = 0; break; 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->ordered_tags = 0; sdev->simple_tags = 0; sdev_printk(KERN_WARNING, sdev, "scsi_adjust_queue_depth, bad queue type, " "disabled\n"); } 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) { if (page == 0xb0 || page == 0x0) pr_err("%s: page_code=0x%x, result=%d.\n", __func__, page, 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 = 0; #if 1 /* check discard configuration */ int retry_count = 2; u8 fail_status; unsigned long flags; retry: memset(buf, 0, buf_len); fail_status = 0; #endif if (sdev->skip_vpd_pages) { fail_status |= (0x1 << 7); goto fail; } /* Ask for all the pages supported by this device */ result = scsi_vpd_inquiry(sdev, buf, 0, buf_len); if (result < 4) { fail_status |= (0x1 << 6); 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 */ fail_status |= (0x1 << 5); goto fail; found: memset(buf, 0, buf_len); result = scsi_vpd_inquiry(sdev, buf, page, buf_len); if (result < 0) { fail_status |= (0x1 << 4); goto fail; } #if 1 /* check discard configuration : SBC3 6.5.3 */ if (sdev->host->by_ufs && page == 0xb0 && buf[3] != 0x3c) goto fail; #endif return 0; fail: #if 1 /* check discard configuration */ if (sdev->host->by_ufs && page == 0xb0) { spin_lock_irqsave(sdev->host->host_lock, flags); pr_err("%s: fail_status=0x%x. result=%d.\n", __func__, fail_status, result); printk("read BlockLimitVPD :"); for (i = 0 ; i < buf_len ; i++) { if (!(i % 16)) printk("\n 0x%02x:", i); printk(" %02x", buf[i]); } printk(".\n"); spin_unlock_irqrestore(sdev->host->host_lock, flags); if (retry_count > 0) { retry_count--; goto retry; } } #endif 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, u64 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, u64 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, u64 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, u64 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"); #ifdef CONFIG_SCSI_MQ_DEFAULT bool scsi_use_blk_mq = true; #else bool scsi_use_blk_mq = false; #endif module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO); 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);