path: root/drivers/block/sx8.c

/*
 *  sx8.c: Driver for Promise SATA SX8 looks-like-I2O hardware
 *
 *  Copyright 2004-2005 Red Hat, Inc.
 *
 *  Author/maintainer:  Jeff Garzik <jgarzik@pobox.com>
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License.  See the file "COPYING" in the main directory of this archive
 *  for more details.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/blk-mq.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/compiler.h>
#include <linux/workqueue.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/ktime.h>
#include <linux/hdreg.h>
#include <linux/dma-mapping.h>
#include <linux/completion.h>
#include <linux/scatterlist.h>
#include <asm/io.h>
#include <linux/uaccess.h>

#if 0
#define CARM_DEBUG
#define CARM_VERBOSE_DEBUG
#else
#undef CARM_DEBUG
#undef CARM_VERBOSE_DEBUG
#endif
#undef CARM_NDEBUG

#define DRV_NAME "sx8"
#define DRV_VERSION "1.0"
#define PFX DRV_NAME ": "

MODULE_AUTHOR("Jeff Garzik");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Promise SATA SX8 block driver");
MODULE_VERSION(DRV_VERSION);

/*
 * SX8 hardware has a single message queue for all ATA ports.
 * When this driver was written, the hardware (firmware?) would
 * corrupt data eventually, if more than one request was outstanding.
 * As one can imagine, having 8 ports bottlenecking on a single
 * command hurts performance.
 *
 * Based on user reports, later versions of the hardware (firmware?)
 * seem to be able to survive with more than one command queued.
 *
 * Therefore, we default to the safe option -- 1 command -- but
 * allow the user to increase this.
 *
 * SX8 should be able to support up to ~60 queued commands (CARM_MAX_REQ),
 * but problems seem to occur when you exceed ~30, even on newer hardware.
 */
static int max_queue = 1;
module_param(max_queue, int, 0444);
MODULE_PARM_DESC(max_queue, "Maximum number of queued commands. (min==1, max==30, safe==1)");


#define NEXT_RESP(idx)	((idx + 1) % RMSG_Q_LEN)

/* 0xf is just arbitrary, non-zero noise; this is sorta like poisoning */
#define TAG_ENCODE(tag)	(((tag) << 16) | 0xf)
#define TAG_DECODE(tag)	(((tag) >> 16) & 0x1f)
#define TAG_VALID(tag)	((((tag) & 0xf) == 0xf) && (TAG_DECODE(tag) < 32))

/* note: prints function name for you */
#ifdef CARM_DEBUG
#define DPRINTK(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ## args)
#ifdef CARM_VERBOSE_DEBUG
#define VPRINTK(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ## args)
#else
#define VPRINTK(fmt, args...)
#endif	/* CARM_VERBOSE_DEBUG */
#else
#define DPRINTK(fmt, args...)
#define VPRINTK(fmt, args...)
#endif	/* CARM_DEBUG */

#ifdef CARM_NDEBUG
#define assert(expr)
#else
#define assert(expr) \
        if(unlikely(!(expr))) {                                   \
        printk(KERN_ERR "Assertion failed! %s,%s,%s,line=%d\n", \
	#expr, __FILE__, __func__, __LINE__);          \
        }
#endif

/* defines only for the constants which don't work well as enums */
struct carm_host;

enum {
	/* adapter-wide limits */
	CARM_MAX_PORTS		= 8,
	CARM_SHM_SIZE		= (4096 << 7),
	CARM_MINORS_PER_MAJOR	= 256 / CARM_MAX_PORTS,
	CARM_MAX_WAIT_Q		= CARM_MAX_PORTS + 1,

	/* command message queue limits */
	CARM_MAX_REQ		= 64,	       /* max command msgs per host */
	CARM_MSG_LOW_WATER	= (CARM_MAX_REQ / 4),	     /* refill mark */

	/* S/G limits, host-wide and per-request */
	CARM_MAX_REQ_SG		= 32,	     /* max s/g entries per request */
	CARM_MAX_HOST_SG	= 600,		/* max s/g entries per host */
	CARM_SG_LOW_WATER	= (CARM_MAX_HOST_SG / 4),   /* re-fill mark */

	/* hardware registers */
	CARM_IHQP		= 0x1c,
	CARM_INT_STAT		= 0x10, /* interrupt status */
	CARM_INT_MASK		= 0x14, /* interrupt mask */
	CARM_HMUC		= 0x18, /* host message unit control */
	RBUF_ADDR_LO		= 0x20, /* response msg DMA buf low 32 bits */
	RBUF_ADDR_HI		= 0x24, /* response msg DMA buf high 32 bits */
	RBUF_BYTE_SZ		= 0x28,
	CARM_RESP_IDX		= 0x2c,
	CARM_CMS0		= 0x30, /* command message size reg 0 */
	CARM_LMUC		= 0x48,
	CARM_HMPHA		= 0x6c,
	CARM_INITC		= 0xb5,

	/* bits in CARM_INT_{STAT,MASK} */
	INT_RESERVED		= 0xfffffff0,
	INT_WATCHDOG		= (1 << 3),	/* watchdog timer */
	INT_Q_OVERFLOW		= (1 << 2),	/* cmd msg q overflow */
	INT_Q_AVAILABLE		= (1 << 1),	/* cmd msg q has free space */
	INT_RESPONSE		= (1 << 0),	/* response msg available */
	INT_ACK_MASK		= INT_WATCHDOG | INT_Q_OVERFLOW,
	INT_DEF_MASK		= INT_RESERVED | INT_Q_OVERFLOW |
				  INT_RESPONSE,

	/* command messages, and related register bits */
	CARM_HAVE_RESP		= 0x01,
	CARM_MSG_READ		= 1,
	CARM_MSG_WRITE		= 2,
	CARM_MSG_VERIFY		= 3,
	CARM_MSG_GET_CAPACITY	= 4,
	CARM_MSG_FLUSH		= 5,
	CARM_MSG_IOCTL		= 6,
	CARM_MSG_ARRAY		= 8,
	CARM_MSG_MISC		= 9,
	CARM_CME		= (1 << 2),
	CARM_RME		= (1 << 1),
	CARM_WZBC		= (1 << 0),
	CARM_RMI		= (1 << 0),
	CARM_Q_FULL		= (1 << 3),
	CARM_MSG_SIZE		= 288,
	CARM_Q_LEN		= 48,

	/* CARM_MSG_IOCTL messages */
	CARM_IOC_SCAN_CHAN	= 5,	/* scan channels for devices */
	CARM_IOC_GET_TCQ	= 13,	/* get tcq/ncq depth */
	CARM_IOC_SET_TCQ	= 14,	/* set tcq/ncq depth */

	IOC_SCAN_CHAN_NODEV	= 0x1f,
	IOC_SCAN_CHAN_OFFSET	= 0x40,

	/* CARM_MSG_ARRAY messages */
	CARM_ARRAY_INFO		= 0,

	ARRAY_NO_EXIST		= (1 << 31),

	/* response messages */
	RMSG_SZ			= 8,	/* sizeof(struct car