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805 lines
22 KiB
805 lines
22 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* scsi.c Copyright (C) 1992 Drew Eckhardt |
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* Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale |
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* Copyright (C) 2002, 2003 Christoph Hellwig |
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* |
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* generic mid-level SCSI driver |
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* Initial versions: Drew Eckhardt |
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* Subsequent revisions: Eric Youngdale |
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* |
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* <[email protected]> |
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* |
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* Bug correction thanks go to : |
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* Rik Faith <[email protected]> |
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* Tommy Thorn <tthorn> |
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* Thomas Wuensche <[email protected]> |
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* |
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* Modified by Eric Youngdale [email protected] or [email protected] to |
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* add scatter-gather, multiple outstanding request, and other |
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* enhancements. |
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* |
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* Native multichannel, wide scsi, /proc/scsi and hot plugging |
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* support added by Michael Neuffer <[email protected]> |
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* |
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* Added request_module("scsi_hostadapter") for kerneld: |
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* (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf) |
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* Bjorn Ekwall <[email protected]> |
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* (changed to kmod) |
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* |
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* Major improvements to the timeout, abort, and reset processing, |
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* as well as performance modifications for large queue depths by |
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* Leonard N. Zubkoff <[email protected]> |
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* |
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* Converted cli() code to spinlocks, Ingo Molnar |
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* |
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* Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli |
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* |
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* out_of_space hacks, D. Gilbert (dpg) 990608 |
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*/ |
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|
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/kernel.h> |
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#include <linux/timer.h> |
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#include <linux/string.h> |
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#include <linux/slab.h> |
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#include <linux/blkdev.h> |
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#include <linux/delay.h> |
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#include <linux/init.h> |
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#include <linux/completion.h> |
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#include <linux/unistd.h> |
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#include <linux/spinlock.h> |
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#include <linux/kmod.h> |
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#include <linux/interrupt.h> |
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#include <linux/notifier.h> |
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#include <linux/cpu.h> |
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#include <linux/mutex.h> |
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#include <linux/async.h> |
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#include <asm/unaligned.h> |
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|
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#include <scsi/scsi.h> |
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#include <scsi/scsi_cmnd.h> |
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#include <scsi/scsi_dbg.h> |
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#include <scsi/scsi_device.h> |
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#include <scsi/scsi_driver.h> |
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#include <scsi/scsi_eh.h> |
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#include <scsi/scsi_host.h> |
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#include <scsi/scsi_tcq.h> |
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|
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#include "scsi_priv.h" |
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#include "scsi_logging.h" |
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|
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#define CREATE_TRACE_POINTS |
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#include <trace/events/scsi.h> |
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|
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/* |
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* Definitions and constants. |
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*/ |
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|
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/* |
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* Note - the initial logging level can be set here to log events at boot time. |
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* After the system is up, you may enable logging via the /proc interface. |
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*/ |
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unsigned int scsi_logging_level; |
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#if defined(CONFIG_SCSI_LOGGING) |
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EXPORT_SYMBOL(scsi_logging_level); |
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#endif |
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|
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/* |
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* Domain for asynchronous system resume operations. It is marked 'exclusive' |
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* to avoid being included in the async_synchronize_full() that is invoked by |
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* dpm_resume(). |
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*/ |
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ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain); |
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EXPORT_SYMBOL(scsi_sd_pm_domain); |
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|
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#ifdef CONFIG_SCSI_LOGGING |
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void scsi_log_send(struct scsi_cmnd *cmd) |
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{ |
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unsigned int level; |
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|
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/* |
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* If ML QUEUE log level is greater than or equal to: |
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* |
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* 1: nothing (match completion) |
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* |
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* 2: log opcode + command of all commands + cmd address |
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* |
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* 3: same as 2 |
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* |
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* 4: same as 3 |
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*/ |
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if (unlikely(scsi_logging_level)) { |
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level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT, |
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SCSI_LOG_MLQUEUE_BITS); |
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if (level > 1) { |
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scmd_printk(KERN_INFO, cmd, |
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"Send: scmd 0x%p\n", cmd); |
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scsi_print_command(cmd); |
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} |
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} |
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} |
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|
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void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) |
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{ |
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unsigned int level; |
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|
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/* |
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* If ML COMPLETE log level is greater than or equal to: |
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* |
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* 1: log disposition, result, opcode + command, and conditionally |
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* sense data for failures or non SUCCESS dispositions. |
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* |
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* 2: same as 1 but for all command completions. |
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* |
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* 3: same as 2 |
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* |
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* 4: same as 3 plus dump extra junk |
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*/ |
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if (unlikely(scsi_logging_level)) { |
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level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, |
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SCSI_LOG_MLCOMPLETE_BITS); |
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if (((level > 0) && (cmd->result || disposition != SUCCESS)) || |
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(level > 1)) { |
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scsi_print_result(cmd, "Done", disposition); |
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scsi_print_command(cmd); |
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if (status_byte(cmd->result) == CHECK_CONDITION) |
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scsi_print_sense(cmd); |
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if (level > 3) |
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scmd_printk(KERN_INFO, cmd, |
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"scsi host busy %d failed %d\n", |
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scsi_host_busy(cmd->device->host), |
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cmd->device->host->host_failed); |
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} |
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} |
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} |
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#endif |
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|
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/** |
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* scsi_finish_command - cleanup and pass command back to upper layer |
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* @cmd: the command |
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* |
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* Description: Pass command off to upper layer for finishing of I/O |
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* request, waking processes that are waiting on results, |
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* etc. |
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*/ |
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void scsi_finish_command(struct scsi_cmnd *cmd) |
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{ |
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struct scsi_device *sdev = cmd->device; |
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struct scsi_target *starget = scsi_target(sdev); |
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struct Scsi_Host *shost = sdev->host; |
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struct scsi_driver *drv; |
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unsigned int good_bytes; |
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|
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scsi_device_unbusy(sdev, cmd); |
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|
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/* |
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* Clear the flags that say that the device/target/host is no longer |
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* capable of accepting new commands. |
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*/ |
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if (atomic_read(&shost->host_blocked)) |
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atomic_set(&shost->host_blocked, 0); |
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if (atomic_read(&starget->target_blocked)) |
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atomic_set(&starget->target_blocked, 0); |
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if (atomic_read(&sdev->device_blocked)) |
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atomic_set(&sdev->device_blocked, 0); |
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|
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/* |
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* If we have valid sense information, then some kind of recovery |
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* must have taken place. Make a note of this. |
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*/ |
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if (SCSI_SENSE_VALID(cmd)) |
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cmd->result |= (DRIVER_SENSE << 24); |
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SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev, |
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"Notifying upper driver of completion " |
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"(result %x)\n", cmd->result)); |
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|
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good_bytes = scsi_bufflen(cmd); |
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if (!blk_rq_is_passthrough(cmd->request)) { |
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int old_good_bytes = good_bytes; |
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drv = scsi_cmd_to_driver(cmd); |
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if (drv->done) |
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good_bytes = drv->done(cmd); |
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/* |
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* USB may not give sense identifying bad sector and |
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* simply return a residue instead, so subtract off the |
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* residue if drv->done() error processing indicates no |
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* change to the completion length. |
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*/ |
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if (good_bytes == old_good_bytes) |
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good_bytes -= scsi_get_resid(cmd); |
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} |
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scsi_io_completion(cmd, good_bytes); |
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} |
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|
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/** |
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* scsi_change_queue_depth - change a device's queue depth |
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* @sdev: SCSI Device in question |
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* @depth: number of commands allowed to be queued to the driver |
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* |
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* Sets the device queue depth and returns the new value. |
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*/ |
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int scsi_change_queue_depth(struct scsi_device *sdev, int depth) |
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{ |
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if (depth > 0) { |
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sdev->queue_depth = depth; |
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wmb(); |
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} |
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if (sdev->request_queue) |
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blk_set_queue_depth(sdev->request_queue, depth); |
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return sdev->queue_depth; |
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} |
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EXPORT_SYMBOL(scsi_change_queue_depth); |
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|
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/** |
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* scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth |
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* @sdev: SCSI Device in question |
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* @depth: Current number of outstanding SCSI commands on this device, |
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* not counting the one returned as QUEUE_FULL. |
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* |
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* Description: This function will track successive QUEUE_FULL events on a |
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* specific SCSI device to determine if and when there is a |
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* need to adjust the queue depth on the device. |
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* |
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* Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth, |
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* -1 - Drop back to untagged operation using host->cmd_per_lun |
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* as the untagged command depth |
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* |
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* Lock Status: None held on entry |
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* |
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* Notes: Low level drivers may call this at any time and we will do |
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* "The Right Thing." We are interrupt context safe. |
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*/ |
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int scsi_track_queue_full(struct scsi_device *sdev, int depth) |
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{ |
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/* |
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* Don't let QUEUE_FULLs on the same |
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* jiffies count, they could all be from |
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* same event. |
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*/ |
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if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4)) |
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return 0; |
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sdev->last_queue_full_time = jiffies; |
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if (sdev->last_queue_full_depth != depth) { |
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sdev->last_queue_full_count = 1; |
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sdev->last_queue_full_depth = depth; |
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} else { |
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sdev->last_queue_full_count++; |
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} |
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if (sdev->last_queue_full_count <= 10) |
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return 0; |
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return scsi_change_queue_depth(sdev, depth); |
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} |
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EXPORT_SYMBOL(scsi_track_queue_full); |
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|
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/** |
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* scsi_vpd_inquiry - Request a device provide us with a VPD page |
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* @sdev: The device to ask |
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* @buffer: Where to put the result |
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* @page: Which Vital Product Data to return |
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* @len: The length of the buffer |
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* |
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* This is an internal helper function. You probably want to use |
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* scsi_get_vpd_page instead. |
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* |
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* Returns size of the vpd page on success or a negative error number. |
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*/ |
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static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer, |
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u8 page, unsigned len) |
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{ |
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int result; |
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unsigned char cmd[16]; |
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if (len < 4) |
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return -EINVAL; |
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cmd[0] = INQUIRY; |
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cmd[1] = 1; /* EVPD */ |
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cmd[2] = page; |
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cmd[3] = len >> 8; |
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cmd[4] = len & 0xff; |
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cmd[5] = 0; /* Control byte */ |
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/* |
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* I'm not convinced we need to try quite this hard to get VPD, but |
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* all the existing users tried this hard. |
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*/ |
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result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, |
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len, NULL, 30 * HZ, 3, NULL); |
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if (result) |
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return -EIO; |
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|
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/* Sanity check that we got the page back that we asked for */ |
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if (buffer[1] != page) |
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return -EIO; |
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return get_unaligned_be16(&buffer[2]) + 4; |
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} |
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|
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/** |
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* scsi_get_vpd_page - Get Vital Product Data from a SCSI device |
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* @sdev: The device to ask |
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* @page: Which Vital Product Data to return |
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* @buf: where to store the VPD |
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* @buf_len: number of bytes in the VPD buffer area |
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* |
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* SCSI devices may optionally supply Vital Product Data. Each 'page' |
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* of VPD is defined in the appropriate SCSI document (eg SPC, SBC). |
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* If the device supports this VPD page, this routine returns a pointer |
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* to a buffer containing the data from that page. The caller is |
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* responsible for calling kfree() on this pointer when it is no longer |
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* needed. If we cannot retrieve the VPD page this routine returns %NULL. |
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*/ |
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int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf, |
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int buf_len) |
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{ |
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int i, result; |
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|
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if (sdev->skip_vpd_pages) |
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goto fail; |
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|
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/* Ask for all the pages supported by this device */ |
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result = scsi_vpd_inquiry(sdev, buf, 0, buf_len); |
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if (result < 4) |
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goto fail; |
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|
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/* If the user actually wanted this page, we can skip the rest */ |
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if (page == 0) |
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return 0; |
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for (i = 4; i < min(result, buf_len); i++) |
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if (buf[i] == page) |
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goto found; |
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if (i < result && i >= buf_len) |
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/* ran off the end of the buffer, give us benefit of doubt */ |
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goto found; |
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/* The device claims it doesn't support the requested page */ |
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goto fail; |
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found: |
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result = scsi_vpd_inquiry(sdev, buf, page, buf_len); |
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if (result < 0) |
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goto fail; |
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|
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return 0; |
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|
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fail: |
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return -EINVAL; |
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} |
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EXPORT_SYMBOL_GPL(scsi_get_vpd_page); |
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|
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/** |
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* scsi_get_vpd_buf - Get Vital Product Data from a SCSI device |
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* @sdev: The device to ask |
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* @page: Which Vital Product Data to return |
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* |
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* Returns %NULL upon failure. |
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*/ |
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static struct scsi_vpd *scsi_get_vpd_buf(struct scsi_device *sdev, u8 page) |
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{ |
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struct scsi_vpd *vpd_buf; |
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int vpd_len = SCSI_VPD_PG_LEN, result; |
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|
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retry_pg: |
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vpd_buf = kmalloc(sizeof(*vpd_buf) + vpd_len, GFP_KERNEL); |
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if (!vpd_buf) |
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return NULL; |
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|
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result = scsi_vpd_inquiry(sdev, vpd_buf->data, page, vpd_len); |
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if (result < 0) { |
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kfree(vpd_buf); |
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return NULL; |
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} |
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if (result > vpd_len) { |
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vpd_len = result; |
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kfree(vpd_buf); |
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goto retry_pg; |
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} |
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vpd_buf->len = result; |
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|
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return vpd_buf; |
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} |
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|
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static void scsi_update_vpd_page(struct scsi_device *sdev, u8 page, |
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struct scsi_vpd __rcu **sdev_vpd_buf) |
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{ |
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struct scsi_vpd *vpd_buf; |
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|
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vpd_buf = scsi_get_vpd_buf(sdev, page); |
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if (!vpd_buf) |
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return; |
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mutex_lock(&sdev->inquiry_mutex); |
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vpd_buf = rcu_replace_pointer(*sdev_vpd_buf, vpd_buf, |
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lockdep_is_held(&sdev->inquiry_mutex)); |
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mutex_unlock(&sdev->inquiry_mutex); |
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|
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if (vpd_buf) |
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kfree_rcu(vpd_buf, rcu); |
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} |
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|
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/** |
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* scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure |
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* @sdev: The device to ask |
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* |
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* Attach the 'Device Identification' VPD page (0x83) and the |
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* 'Unit Serial Number' VPD page (0x80) to a SCSI device |
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* structure. This information can be used to identify the device |
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* uniquely. |
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*/ |
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void scsi_attach_vpd(struct scsi_device *sdev) |
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{ |
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int i; |
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struct scsi_vpd *vpd_buf; |
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|
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if (!scsi_device_supports_vpd(sdev)) |
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return; |
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|
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/* Ask for all the pages supported by this device */ |
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vpd_buf = scsi_get_vpd_buf(sdev, 0); |
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if (!vpd_buf) |
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return; |
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|
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for (i = 4; i < vpd_buf->len; i++) { |
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if (vpd_buf->data[i] == 0x0) |
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scsi_update_vpd_page(sdev, 0x0, &sdev->vpd_pg0); |
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if (vpd_buf->data[i] == 0x80) |
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scsi_update_vpd_page(sdev, 0x80, &sdev->vpd_pg80); |
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if (vpd_buf->data[i] == 0x83) |
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scsi_update_vpd_page(sdev, 0x83, &sdev->vpd_pg83); |
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if (vpd_buf->data[i] == 0x89) |
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scsi_update_vpd_page(sdev, 0x89, &sdev->vpd_pg89); |
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} |
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kfree(vpd_buf); |
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} |
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|
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/** |
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* scsi_report_opcode - Find out if a given command opcode is supported |
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* @sdev: scsi device to query |
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* @buffer: scratch buffer (must be at least 20 bytes long) |
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* @len: length of buffer |
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* @opcode: opcode for command to look up |
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* |
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* Uses the REPORT SUPPORTED OPERATION CODES to look up the given |
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* opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is |
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* unsupported and 1 if the device claims to support the command. |
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*/ |
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int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer, |
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unsigned int len, unsigned char opcode) |
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{ |
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unsigned char cmd[16]; |
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struct scsi_sense_hdr sshdr; |
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int result; |
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|
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if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3) |
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return -EINVAL; |
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|
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memset(cmd, 0, 16); |
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cmd[0] = MAINTENANCE_IN; |
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cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES; |
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cmd[2] = 1; /* One command format */ |
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cmd[3] = opcode; |
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put_unaligned_be32(len, &cmd[6]); |
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memset(buffer, 0, len); |
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|
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result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
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&sshdr, 30 * HZ, 3, NULL); |
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|
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if (result && scsi_sense_valid(&sshdr) && |
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sshdr.sense_key == ILLEGAL_REQUEST && |
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(sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00) |
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return -EINVAL; |
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|
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if ((buffer[1] & 3) == 3) /* Command supported */ |
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return 1; |
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|
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return 0; |
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} |
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EXPORT_SYMBOL(scsi_report_opcode); |
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|
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/** |
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* scsi_device_get - get an additional reference to a scsi_device |
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* @sdev: device to get a reference to |
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* |
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* Description: Gets a reference to the scsi_device and increments the use count |
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* of the underlying LLDD module. You must hold host_lock of the |
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* parent Scsi_Host or already have a reference when calling this. |
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* |
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* This will fail if a device is deleted or cancelled, or when the LLD module |
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* is in the process of being unloaded. |
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*/ |
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int scsi_device_get(struct scsi_device *sdev) |
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{ |
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if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL) |
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goto fail; |
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if (!get_device(&sdev->sdev_gendev)) |
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goto fail; |
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if (!try_module_get(sdev->host->hostt->module)) |
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goto fail_put_device; |
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return 0; |
|
|
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fail_put_device: |
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put_device(&sdev->sdev_gendev); |
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fail: |
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return -ENXIO; |
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} |
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EXPORT_SYMBOL(scsi_device_get); |
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|
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/** |
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* scsi_device_put - release a reference to a scsi_device |
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* @sdev: device to release a reference on. |
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* |
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* Description: Release a reference to the scsi_device and decrements the use |
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* count of the underlying LLDD module. The device is freed once the last |
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* user vanishes. |
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*/ |
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void scsi_device_put(struct scsi_device *sdev) |
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{ |
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module_put(sdev->host->hostt->module); |
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put_device(&sdev->sdev_gendev); |
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} |
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EXPORT_SYMBOL(scsi_device_put); |
|
|
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/* helper for shost_for_each_device, see that for documentation */ |
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struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, |
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struct scsi_device *prev) |
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{ |
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struct list_head *list = (prev ? &prev->siblings : &shost->__devices); |
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struct scsi_device *next = NULL; |
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unsigned long flags; |
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|
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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->sdev_state == SDEV_DEL) |
|
continue; |
|
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"); |
|
|
|
static int __init init_scsi(void) |
|
{ |
|
int 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(); |
|
} |
|
|
|
subsys_initcall(init_scsi); |
|
module_exit(exit_scsi);
|
|
|