path: root/drivers/scsi/vmw_pvscsi.c

/*
 * Linux driver for VMware's para-virtualized SCSI HBA.
 *
 * Copyright (C) 2008-2014, VMware, Inc. All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; version 2 of the License and no later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/pci.h>

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

#include "vmw_pvscsi.h"

#define PVSCSI_LINUX_DRIVER_DESC "VMware PVSCSI driver"

MODULE_DESCRIPTION(PVSCSI_LINUX_DRIVER_DESC);
MODULE_AUTHOR("VMware, Inc.");
MODULE_LICENSE("GPL");
MODULE_VERSION(PVSCSI_DRIVER_VERSION_STRING);

#define PVSCSI_DEFAULT_NUM_PAGES_PER_RING	8
#define PVSCSI_DEFAULT_NUM_PAGES_MSG_RING	1
#define PVSCSI_DEFAULT_QUEUE_DEPTH		254
#define SGL_SIZE				PAGE_SIZE

struct pvscsi_sg_list {
	struct PVSCSISGElement sge[PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT];
};

struct pvscsi_ctx {
	/*
	 * The index of the context in cmd_map serves as the context ID for a
	 * 1-to-1 mapping completions back to requests.
	 */
	struct scsi_cmnd	*cmd;
	struct pvscsi_sg_list	*sgl;
	struct list_head	list;
	dma_addr_t		dataPA;
	dma_addr_t		sensePA;
	dma_addr_t		sglPA;
	struct completion	*abort_cmp;
};

struct pvscsi_adapter {
	char				*mmioBase;
	u8				rev;
	bool				use_msg;
	bool				use_req_threshold;

	spinlock_t			hw_lock;

	struct workqueue_struct		*workqueue;
	struct work_struct		work;

	struct PVSCSIRingReqDesc	*req_ring;
	unsigned			req_pages;
	unsigned			req_depth;
	dma_addr_t			reqRingPA;

	struct PVSCSIRingCmpDesc	*cmp_ring;
	unsigned			cmp_pages;
	dma_addr_t			cmpRingPA;

	struct PVSCSIRingMsgDesc	*msg_ring;
	unsigned			msg_pages;
	dma_addr_t			msgRingPA;

	struct PVSCSIRingsState		*rings_state;
	dma_addr_t			ringStatePA;

	struct pci_dev			*dev;
	struct Scsi_Host		*host;

	struct list_head		cmd_pool;
	struct pvscsi_ctx		*cmd_map;
};


/* Command line parameters */
static int pvscsi_ring_pages;
static int pvscsi_msg_ring_pages = PVSCSI_DEFAULT_NUM_PAGES_MSG_RING;
static int pvscsi_cmd_per_lun    = PVSCSI_DEFAULT_QUEUE_DEPTH;
static bool pvscsi_disable_msi;
static bool pvscsi_disable_msix;
static bool pvscsi_use_msg       = true;
static bool pvscsi_use_req_threshold = true;

#define PVSCSI_RW (S_IRUSR | S_IWUSR)

module_param_named(ring_pages, pvscsi_ring_pages, int, PVSCSI_RW);
MODULE_PARM_DESC(ring_pages, "Number of pages per req/cmp ring - (default="
		 __stringify(PVSCSI_DEFAULT_NUM_PAGES_PER_RING)
		 "[up to 16 targets],"
		 __stringify(PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)
		 "[for 16+ targets])");

module_param_named(msg_ring_pages, pvscsi_msg_ring_pages, int, PVSCSI_RW);
MODULE_PARM_DESC(msg_ring_pages, "Number of pages for the msg ring - (default="
		 __stringify(PVSCSI_DEFAULT_NUM_PAGES_MSG_RING) ")");

module_param_named(cmd_per_lun, pvscsi_cmd_per_lun, int, PVSCSI_RW);
MODULE_PARM_DESC(cmd_per_lun, "Maximum commands per lun - (default="
		 __stringify(PVSCSI_DEFAULT_QUEUE_DEPTH) ")");

module_param_named(disable_msi, pvscsi_disable_msi, bool, PVSCSI_RW);
MODULE_PARM_DESC(disable_msi, "Disable MSI use in driver - (default=0)");

module_param_named(disable_msix, pvscsi_disable_msix, bool, PVSCSI_RW);
MODULE_PARM_DESC(disable_msix, "Disable MSI-X use in driver - (default=0)");

module_param_name