847 lines
23 KiB
C
847 lines
23 KiB
C
/*
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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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* <drew@colorado.edu>
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*
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* Bug correction thanks go to :
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* Rik Faith <faith@cs.unc.edu>
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* Tommy Thorn <tthorn>
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* Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de>
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*
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* Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu 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 <mike@i-connect.net>
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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 <bj0rn@blox.se>
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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 <lnz@dandelion.com>
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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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#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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#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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#include "scsi_priv.h"
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#include "scsi_logging.h"
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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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* Definitions and constants.
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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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/* sd, scsi core and power management need to coordinate flushing async actions */
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ASYNC_DOMAIN(scsi_sd_probe_domain);
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EXPORT_SYMBOL(scsi_sd_probe_domain);
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/*
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* Separate domain (from scsi_sd_probe_domain) to maximize the benefit of
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* asynchronous system resume operations. It is marked 'exclusive' to avoid
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* 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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* scsi_put_command - Free a scsi command block
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* @cmd: command block to free
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*
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* Returns: Nothing.
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*
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* Notes: The command must not belong to any lists.
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*/
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void scsi_put_command(struct scsi_cmnd *cmd)
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{
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scsi_del_cmd_from_list(cmd);
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BUG_ON(delayed_work_pending(&cmd->abort_work));
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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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* 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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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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* 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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atomic_read(&cmd->device->host->host_busy),
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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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* scsi_cmd_get_serial - Assign a serial number to a command
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* @host: the scsi host
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* @cmd: command to assign serial number to
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*
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* Description: a serial number identifies a request for error recovery
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* and debugging purposes. Protected by the Host_Lock of host.
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*/
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void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
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{
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cmd->serial_number = host->cmd_serial_number++;
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if (cmd->serial_number == 0)
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cmd->serial_number = host->cmd_serial_number++;
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}
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EXPORT_SYMBOL(scsi_cmd_get_serial);
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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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scsi_device_unbusy(sdev);
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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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* 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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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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* 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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* 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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* 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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/* 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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* 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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if (sdev->skip_vpd_pages)
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goto fail;
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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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/* 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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return 0;
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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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* 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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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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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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return vpd_buf;
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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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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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rcu_swap_protected(*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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if (vpd_buf)
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kfree_rcu(vpd_buf, rcu);
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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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if (!scsi_device_supports_vpd(sdev))
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return;
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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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for (i = 4; i < vpd_buf->len; i++) {
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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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}
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kfree(vpd_buf);
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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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*/
|
|
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.
|
|
*
|
|
* This will fail if a device is deleted or cancelled, or when the LLD module
|
|
* is in the process of being unloaded.
|
|
*/
|
|
int scsi_device_get(struct scsi_device *sdev)
|
|
{
|
|
if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL)
|
|
goto fail;
|
|
if (!get_device(&sdev->sdev_gendev))
|
|
goto fail;
|
|
if (!try_module_get(sdev->host->hostt->module))
|
|
goto fail_put_device;
|
|
return 0;
|
|
|
|
fail_put_device:
|
|
put_device(&sdev->sdev_gendev);
|
|
fail:
|
|
return -ENXIO;
|
|
}
|
|
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)
|
|
{
|
|
module_put(sdev->host->hostt->module);
|
|
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->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");
|
|
|
|
#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);
|