Merge branch 'sx8' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/misc-2.6 (9be16a03) · Commits · e / devices / android_kernel_teracube_2e

drivers/block/sx8.c

+37 −14

Original line number	Diff line number	Diff line
		/*
		* sx8.c: Driver for Promise SATA SX8 looks-like-I2O hardware
		*
		* Copyright 2004 Red Hat, Inc.
		* Copyright 2004-2005 Red Hat, Inc.
		*
		* Author/maintainer: Jeff Garzik <jgarzik@pobox.com>
		*
		@@ -31,10 +31,6 @@
		#include <asm/semaphore.h>
		#include <asm/uaccess.h>

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

		#if 0
		#define CARM_DEBUG
		#define CARM_VERBOSE_DEBUG
		@@ -45,9 +41,35 @@ MODULE_DESCRIPTION("Promise SATA SX8 block driver");
		#undef CARM_NDEBUG

		#define DRV_NAME "sx8"
		#define DRV_VERSION "0.8"
		#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 */
		@@ -90,12 +112,10 @@ enum {

		/* command message queue limits */
		CARM_MAX_REQ = 64, /* max command msgs per host */
		CARM_MAX_Q = 1, /* one command at a time */
		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_SG_BOUNDARY = 0xffffUL, /* s/g segment boundary */
		CARM_MAX_HOST_SG = 600, /* max s/g entries per host */
		CARM_SG_LOW_WATER = (CARM_MAX_HOST_SG / 4), /* re-fill mark */

		@@ -181,6 +201,10 @@ enum {
		FL_DYN_MAJOR = (1 << 17),
		};

		enum {
		CARM_SG_BOUNDARY = 0xffffUL, /* s/g segment boundary */
		};

		enum scatter_gather_types {
		SGT_32BIT = 0,
		SGT_64BIT = 1,
		@@ -218,7 +242,6 @@ static const char *state_name[] = {

		struct carm_port {
		unsigned int port_no;
		unsigned int n_queued;
		struct gendisk *disk;
		struct carm_host *host;

		@@ -509,7 +532,7 @@ static struct carm_request carm_get_request(struct carm_host host)
		if (host->hw_sg_used >= (CARM_MAX_HOST_SG - CARM_MAX_REQ_SG))
		return NULL;

		for (i = 0; i < CARM_MAX_Q; i++)
		for (i = 0; i < max_queue; i++)
		if ((host->msg_alloc & (1ULL << i)) == 0) {
		struct carm_request *crq = &host->req[i];
		crq->port = NULL;
		@@ -528,7 +551,7 @@ static struct carm_request carm_get_request(struct carm_host host)

		static int carm_put_request(struct carm_host host, struct carm_request crq)
		{
		assert(crq->tag < CARM_MAX_Q);
		assert(crq->tag < max_queue);

		if (unlikely((host->msg_alloc & (1ULL << crq->tag)) == 0))
		return -EINVAL; /* tried to clear a tag that was not active */
		@@ -791,7 +814,7 @@ static inline void carm_end_rq(struct carm_host host, struct carm_request crq,
		int is_ok)
		{
		carm_end_request_queued(host, crq, is_ok);
		if (CARM_MAX_Q == 1)
		if (max_queue == 1)
		carm_round_robin(host);
		else if ((host->n_msgs <= CARM_MSG_LOW_WATER) &&
		(host->hw_sg_used <= CARM_SG_LOW_WATER)) {