path: root/drivers/scsi/snic/snic_main.c

// SPDX-License-Identifier: GPL-2.0-only
// Copyright 2014 Cisco Systems, Inc.  All rights reserved.

#include <linux/module.h>
#include <linux/mempool.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/skbuff.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>

#include "snic.h"
#include "snic_fwint.h"

#define PCI_DEVICE_ID_CISCO_SNIC	0x0046

/* Supported devices by snic module */
static const struct pci_device_id snic_id_table[] = {
	{PCI_DEVICE(0x1137, PCI_DEVICE_ID_CISCO_SNIC) },
	{ 0, }	/* end of table */
};

unsigned int snic_log_level = 0x0;
module_param(snic_log_level, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(snic_log_level, "bitmask for snic logging levels");

#ifdef CONFIG_SCSI_SNIC_DEBUG_FS
unsigned int snic_trace_max_pages = 16;
module_param(snic_trace_max_pages, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(snic_trace_max_pages,
		"Total allocated memory pages for snic trace buffer");

#endif
unsigned int snic_max_qdepth = SNIC_DFLT_QUEUE_DEPTH;
module_param(snic_max_qdepth, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(snic_max_qdepth, "Queue depth to report for each LUN");

/*
 * snic_sdev_init : callback function to SCSI Mid Layer, called on
 * scsi device initialization.
 */
static int
snic_sdev_init(struct scsi_device *sdev)
{
	struct snic_tgt *tgt = starget_to_tgt(scsi_target(sdev));

	if (!tgt || snic_tgt_chkready(tgt))
		return -ENXIO;

	return 0;
}

/*
 * snic_sdev_configure : callback function to SCSI Mid Layer, called on
 * scsi device initialization.
 */
static int
snic_sdev_configure(struct scsi_device *sdev, struct queue_limits *lim)
{
	struct snic *snic = shost_priv(sdev->host);
	u32 qdepth = 0, max_ios = 0;
	int tmo = SNIC_DFLT_CMD_TIMEOUT * HZ;

	/* Set Queue Depth */
	max_ios = snic_max_qdepth;
	qdepth = min_t(u32, max_ios, SNIC_MAX_QUEUE_DEPTH);
	scsi_change_queue_depth(sdev, qdepth);

	if (snic->fwinfo.io_tmo > 1)
		tmo = snic->fwinfo.io_tmo * HZ;

	/* FW requires extended timeouts */
	blk_queue_rq_timeout(sdev->request_queue, tmo);

	return 0;
}

static int
snic_change_queue_depth(struct scsi_device *sdev, int qdepth)
{
	struct snic *snic = shost_priv(sdev->host);
	int qsz = 0;

	qsz = min_t(u32, qdepth, SNIC_MAX_QUEUE_DEPTH);
	if (qsz < sdev->queue_depth)
		atomic64_inc(&snic->s_stats.misc.qsz_rampdown);
	else if (qsz > sdev->queue_depth)
		atomic64_inc(&snic->s_stats.misc.qsz_rampup);

	atomic64_set(&snic->s_stats.misc.last_qsz, sdev->queue_depth);

	scsi_change_queue_depth(sdev, qsz);

	return sdev->queue_depth;
}

static const struct scsi_host_template snic_host_template = {
	.module = THIS_MODULE,
	.name = SNIC_DRV_NAME,
	.queuecommand = snic_queuecommand,
	.eh_abort_handler = snic_abort_cmd,
	.eh_device_reset_handler = snic_device_reset,
	.eh_host_reset_handler = snic_host_reset,
	.sdev_init = snic_sdev_init,
	.sdev_configure = snic_sdev_configure,
	.change_queue_depth = snic_change_queue_depth,
	.this_id = -1,
	.cmd_per_lun = SNIC_DFLT_QUEUE_DEPTH,
	.can_queue = SNIC_MAX_IO_REQ,
	.sg_tablesize = SNIC_MAX_SG_DESC_CNT,
	.max_sectors = 0x800,
	.shost_groups = snic_host_groups,
	.track_queue_depth = 1,
	.cmd_size = sizeof(struct snic_internal_io_state),
	.proc_name = "snic_scsi",
};

/*
 * snic_handle_link_event : Handles link events such as link up/down/error
 */
void
snic_handle_link_event(struct snic *snic)
{
	unsigned long flags;

	spin_lock_irqsave(&snic->snic_lock, flags);
	if (snic->stop_link_events) {
		spin_unlock_irqrestore(&snic->snic_lock, flags);

		return;
	}
	spin_unlock_irqrestore(&snic->snic_lock, flags);

	queue_work(snic_glob->event_q, &snic->link_work);
} /* end of snic_handle_link_event */

/*
 * snic_notify_set : sets notification area
 * This notification area is to receive events from fw
 * Note: snic supports only MSIX interrupts, in which we can just call
 *  svnic_dev_notify_set directly
 */
static int
snic_notify_set(struct