path: root/drivers/scsi/scsi.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  scsi.c Copyright (C) 1992 Drew Eckhardt
 *         Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
 *         Copyright (C) 2002, 2003 Christoph Hellwig
 *
 *  generic mid-level SCSI driver
 *      Initial versions: Drew Eckhardt
 *      Subsequent revisions: Eric Youngdale
 *
 *  <drew@colorado.edu>
 *
 *  Bug correction thanks go to :
 *      Rik Faith <faith@cs.unc.edu>
 *      Tommy Thorn <tthorn>
 *      Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de>
 *
 *  Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to
 *  add scatter-gather, multiple outstanding request, and other
 *  enhancements.
 *
 *  Native multichannel, wide scsi, /proc/scsi and hot plugging
 *  support added by Michael Neuffer <mike@i-connect.net>
 *
 *  Added request_module("scsi_hostadapter") for kerneld:
 *  (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf)
 *  Bjorn Ekwall  <bj0rn@blox.se>
 *  (changed to kmod)
 *
 *  Major improvements to the timeout, abort, and reset processing,
 *  as well as performance modifications for large queue depths by
 *  Leonard N. Zubkoff <lnz@dandelion.com>
 *
 *  Converted cli() code to spinlocks, Ingo Molnar
 *
 *  Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
 *
 *  out_of_space hacks, D. Gilbert (dpg) 990608
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/unistd.h>
#include <linux/spinlock.h>
#include <linux/kmod.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/mutex.h>
#include <linux/unaligned.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>

#include "scsi_priv.h"
#include "scsi_logging.h"

#define CREATE_TRACE_POINTS
#include <trace/events/scsi.h>

/*
 * Definitions and constants.
 */

/*
 * Note - the initial logging level can be set here to log events at boot time.
 * After the system is up, you may enable logging via the /proc interface.
 */
unsigned int scsi_logging_level;
#if defined(CONFIG_SCSI_LOGGING)
EXPORT_SYMBOL(scsi_logging_level);
#endif

#ifdef CONFIG_SCSI_LOGGING
void scsi_log_send(struct scsi_cmnd *cmd)
{
	unsigned int level;

	/*
	 * If ML QUEUE log level is greater than or equal to:
	 *
	 * 1: nothing (match completion)
	 *
	 * 2: log opcode + command of all commands + cmd address
	 *
	 * 3: same as 2
	 *
	 * 4: same as 3
	 */
	if (unlikely(scsi_logging_level)) {
		level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
				       SCSI_LOG_MLQUEUE_BITS);
		if (level > 1) {
			scmd_printk(KERN_INFO, cmd,
				    "Send: scmd 0x%p\n", cmd);
			scsi_print_command(cmd);
		}
	}
}

void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
{
	unsigned int level;

	/*
	 * If ML COMPLETE log level is greater than or equal to:
	 *
	 * 1: log disposition, result, opcode + command, and conditionally
	 * sense data for failures or non SUCCESS dispositions.
	 *
	 * 2: same as 1 but for all command completions.
	 *
	 * 3: same as 2
	 *
	 * 4: same as 3 plus dump extra junk
	 */
	if (unlikely(scsi_logging_level)) {
		level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
				       SCSI_LOG_MLCOMPLETE_BITS);
		if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
		    (level > 1)) {
			scsi_print_result(cmd, "Done", disposition);
			scsi_print_command(cmd);
			if (scsi_status_is_check_condition(cmd->result))
				scsi_print_sense(cmd);
			if (level > 3)
				scmd_printk(KERN_INFO, cmd,
					    "scsi host busy %d failed %d\n",
					    scsi_host_busy(cmd->device->host),
					    cmd->device->host->host_failed);
		}
	}
}
#endif

/**
 * scsi_finish_command - cleanup and pass command back to upper layer
 * @cmd: the command
 *
 * Description: Pass command off to upper layer for finishing of I/O
 *              request, waking processes that are waiting on results,
 *              etc.
 */
void scsi_finish_command(struct scsi_cmnd *cmd)
{
	struct scsi_device *sdev = cmd->device;
	struct scsi_target *starget = scsi_target(sdev);
	struct Scsi_Host *shost = sdev->host;
	struct scsi_driver *drv;
	unsigned int good_bytes;

	scsi_device_unbusy(sdev, cmd);

	/*
	 * Clear the flags that say that the device/target/host is no longer
	 * capable of accepting new commands.
	 */
	if (atomic_read(&shost->host_blocked))
		atomic_set(&shost->host_blocked, 0);
	if (atomic_read(&starget->target_blocked))
		atomic_set(&starget->target_blocked, 0);
	if (atomic_read(&sdev->device_blocked))
		atomic_set(&sdev->device_blocked, 0);

	SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
				"Notifying upper driver of completion "
				"(result %x)\n", cmd->result));

	good_bytes = scsi_bufflen(cmd);
	if (