/*
* Engenio/LSI RDAC DM HW handler
*
* Copyright (C) 2005 Mike Christie. All rights reserved.
* Copyright (C) Chandra Seetharaman, IBM Corp. 2007
*
* 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; either version 2 of the License, or
* (at your option) any 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. 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_eh.h>
#define DM_MSG_PREFIX "multipath rdac"
#include "dm.h"
#include "dm-hw-handler.h"
#define RDAC_DM_HWH_NAME "rdac"
#define RDAC_DM_HWH_VER "0.4"
/*
* LSI mode page stuff
*
* These struct definitions and the forming of the
* mode page were taken from the LSI RDAC 2.4 GPL'd
* driver, and then converted to Linux conventions.
*/
#define RDAC_QUIESCENCE_TIME 20;
/*
* Page Codes
*/
#define RDAC_PAGE_CODE_REDUNDANT_CONTROLLER 0x2c
/*
* Controller modes definitions
*/
#define RDAC_MODE_TRANSFER_ALL_LUNS 0x01
#define RDAC_MODE_TRANSFER_SPECIFIED_LUNS 0x02
/*
* RDAC Options field
*/
#define RDAC_FORCED_QUIESENCE 0x02
#define RDAC_FAILOVER_TIMEOUT (60 * HZ)
struct rdac_mode_6_hdr {
u8 data_len;
u8 medium_type;
u8 device_params;
u8 block_desc_len;
};
struct rdac_mode_10_hdr {
u16 data_len;
u8 medium_type;
u8 device_params;
u16 reserved;
u16 block_desc_len;
};
struct rdac_mode_common {
u8 controller_serial[16];
u8 alt_controller_serial[16];
u8 rdac_mode[2];
u8 alt_rdac_mode[2];
u8 quiescence_timeout;
u8 rdac_options;
};
struct rdac_pg_legacy {
struct rdac_mode_6_hdr hdr;
u8 page_code;
u8 page_len;
struct rdac_mode_common common;
#define MODE6_MAX_LUN 32
u8 lun_table[MODE6_MAX_LUN];
u8 reserved2[32];
u8 reserved3;
u8 reserved4;
};
struct rdac_pg_expanded {
struct rdac_mode_10_hdr hdr;
u8 page_code;
u8 subpage_code;
u8 page_len[2];
struct rdac_mode_common common;
u8 lun_table[256];
u8 reserved3;
u8 reserved4;
};
struct c9_inquiry {
u8 peripheral_info;
u8 page_code; /* 0xC9 */
u8 reserved1;
u8 page_len;
u8 page_id[4]; /* "vace" */
u8 avte_cvp;
u8 path_prio;
u8 reserved2[38];
};
#define SUBSYS_ID_LEN 16
#define SLOT_ID_LEN 2
struct c4_inquiry {
u8 peripheral_info;
u8 page_code; /* 0xC4 */
u8 reserved1;
u8 page_len;
u8 page_id[4]; /* "subs" */
u8 subsys_id[SUBSYS_ID_LEN];
u8 revision[4];
u8 slot_id[SLOT_ID_LEN];
u8 reserved[2];
};
struct rdac_controller {
u8 subsys_id[SUBSYS_ID_LEN];
u8 slot_id[SLOT_ID_LEN];
int use_10_ms;
struct kref kref;
struct list_head node; /* list of all controllers */
spinlock_t lock;
int submitted;
struct list_head cmd_list; /* list of commands to be submitted */
union {
struct rdac_pg_legacy legacy;
struct rdac_pg_expanded expanded;
} mode_select;
};
struct c8_inquiry {
u8 peripheral_info;
u8 page_code; /* 0xC8 */
u8 reserved1;
u8 page_len;
u8 page_id[4]; /* "edid" */
u8 reserved2[3];
u8 vol_uniq_id_len;
u8 vol_uniq_id[16];
u8 vol_user_label_len;
u8 vol_user_label[60];
u8 array_uniq_id_len;
u8 array_unique_id[16];
u8 array_user_label_len;
u8 array_user_label[60];
u8 lun[8];
};
struct c2_inquiry {
u8 peripheral_info;
u8 page_code; /* 0xC2 */
u8 reserved1;
u8 page_len;
u8 page_id[4]; /* "swr4" */
u8 sw_version[3];
u8 sw_date[3];
u8 features_enabled;
u8 max_lun_supported;
u8 partitions[239]; /* Total allocation length should be 0xFF */
};
struct rdac_handler {
struct list_head entry; /* list waiting to submit MODE SELECT */
unsigned timeout;
struct rdac_controller *ctlr;
#define UNINITIALIZED_LUN (1 << 8)
unsigned lun;
unsigned char sense[SCSI_SENSE_BUFFERSIZE];
struct dm_path *path;
struct work_struct work;
#define SEND_C2_INQUIRY 1
#define SEND_C4_INQUIRY 2
#define SEND_C8_INQUIRY 3
#define SEND_C9_INQUIRY 4
#define SEND_MODE_SELECT 5
int cmd_to_send;
union {
struct c2_inquiry c2;
struct c4_inquiry c4;
struct c8_inquiry c8;
struct c9_inquiry c9;
} inq;
};
static LIST_HEAD(ctlr_list);
static DEFINE_SPINLOCK(list_lock);
static struct workqueue_struct *rdac_wkqd;
static inline int had_failures(struct request *req, int error)
{
return (error || host_byte(req->errors) != DID_OK ||
msg_byte(req->errors) != COMMAND_COMPLETE);
}
static void rdac_resubmit_all(struct rdac_handler *h)
{
struct rdac_controller *ctlr = h->ctlr;
struct rdac_handler *tmp, *h1;
spin_lock(&ctlr->lock);
list_for_each_entry_safe(h1, tmp, &ctlr->cmd_list, entry) {
h1->cmd_to_send = SEND_C9_INQUIRY;
queue_work(rdac_wkqd, &h1->work);
list_del(&h1->entry);
}
ctlr->submitted = 0;
spin_unlock(&ctlr->lock);
}
static void mode_select_endio(struct request *req, int error)
{
struct rdac_handler *h = req->end_io_data;
struct scsi_sense_hdr sense_hdr;
int sense = 0, fail = 0;
if (had_failures(req, error)) {
fail = 1;
goto failed;
}
if (status_byte(req->errors) == CHECK_CONDITION) {
scsi_normalize_sense(req->sense, SCSI_SENSE_BUFFERSIZE,
&sense_hdr);
sense = (sense_hdr.sense_key << 16) | (sense_hdr.asc << 8) |
sense_hdr.ascq;
/* If it is retryable failure, submit the c9 inquiry again */
if (sense == 0x59136 || sense == 0x68b02 || sense == 0xb8b02 ||
sense == 0x62900) {
/* 0x59136 - Command lock contention
* 0x[6b]8b02 - Quiesense in progress or achieved
* 0x62900 - Power On, Reset, or Bus Device Reset
*/
h->cmd_to_send = SEND_C9_INQUIRY;
queue_work(rdac_wkqd, &h->work);
goto done;
}
if (sense)
DMINFO("MODE_SELECT failed on %s with sense 0x%x",
h->path->dev->name, sense);
}
failed:
if (fail || sense)
dm_pg_init_complete(h->path, MP_FAIL_PATH);
else
dm_pg_init_complete(h->path, 0);
done:
rdac_resubmit_all(h);
__blk_put_request(req->q, req);
}
static struct request *get_rdac_req(struct rdac_handler *h,
void *buffer, unsigned buflen, int rw)
{
struct request *rq;
struct request_queue *q = bdev_get_queue(h->path->dev->bdev);
rq = blk_get_request(q, rw, GFP_KERNEL);
if (!rq) {
DMINFO("get_rdac_req: blk_get_request failed");
return NULL;
}
if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_KERNEL)) {
blk_put_request(rq);
DMINFO("get_rdac_req: blk_rq_map_kern failed");
return NULL;
}
memset(&rq->cmd, 0, BLK_MAX_CDB);
rq->sense = h->sense;
memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
rq->sense_len = 0;
rq->end_io_data = h;
rq->timeout = h->timeout;
rq->cmd_type = REQ_TYPE_BLOCK_PC;
rq->cmd_flags |= REQ_FAILFAST | REQ_NOMERGE;
return rq;
}
static struct request *rdac_failover_get(struct rdac_handler *h)
{
struct request *rq;
struct rdac_mode_common *common;
unsigned data_size;
if (h->ctlr->use_10_ms) {
struct rdac_pg_expanded *rdac_pg;
data_size = sizeof(struct rdac_pg_expanded);
rdac_pg = &h->ctlr->mode_select.expanded;
memset(rdac_pg, 0, data_size);
common = &rdac_pg->common;
rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
rdac_pg->subpage_code = 0x1;
rdac_pg->page_len[0] = 0x01;
rdac_pg->page_len[1] = 0x28;
rdac_pg->lun_table[h->lun] = 0x81;
} else {
struct rdac_pg_legacy *rdac_pg;
data_size = sizeof(struct rdac_pg_legacy);
rdac_pg = &h->ctlr->mode_select.legacy;
memset(rdac_pg, 0, data_size);
common = &rdac_pg->common;
rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
rdac_pg->page_len = 0x68;
rdac_pg->lun_table[h->lun] = 0x81;
}
common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
common->rdac_options = RDAC_FORCED_QUIESENCE;
/* get request for block layer packet command */
rq = get_rdac_req(h, &h->ctlr->mode_select, data_size, WRITE);
if (!rq) {
DMERR("rdac_failover_get: no rq");
return NULL;
}
/* Prepare the command. */
if (h->ctlr->use_10_ms) {
rq->cmd[0] = MODE_SELECT_10;
rq->cmd[7] = data_size >> 8;
rq->cmd[8] = data_size & 0xff;
} else {
rq->cmd[0] = MODE_SELECT;
rq->cmd[4] = data_size;
}
rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
return rq;
}
/* Acquires h->ctlr->lock */
static void submit_mode_select(struct rdac_handler *h)
{
struct request *rq;
struct request_queue *q = bdev_get_queue(h->path->dev->bdev);
spin_lock(&h->ctlr->lock);
if (h->ctlr->submitted) {
list_add(&h->entry, &h->ctlr->cmd_list);
goto drop_lock;
}
if (!q) {
DMINFO("submit_mode_select: no queue");
goto fail_path;
}
rq = rdac_failover_get(h);
if (!rq) {
DMERR("submit_mode_select: no rq");
goto fail_path;
}
DMINFO("queueing MODE_SELECT command on %s", h->path->dev->name);
blk_execute_rq_nowait(q, NULL, rq, 1, mode_select_endio);
h->ctlr->submitted = 1;
goto drop_lock;
fail_path:
dm_pg_init_complete(h->path, MP_FAIL_PATH);
drop_lock:
spin_unlock(&h->ctlr->lock);
}
static void release_ctlr(struct kref *kref)
{
struct rdac_controller *ctlr;
ctlr = container_of(kref, struct rdac_controller, kref);
spin_lock(&list_lock);
list_del(&ctlr->node);
spin_unlock(&list_lock);
kfree(ctlr);
}
static struct rdac_controller *get_controller(u8 *subsys_id, u8 *slot_id)
{
struct rdac_controller *ctlr, *tmp;
spin_lock(&list_lock);
list_for_each_entry(tmp, &ctlr_list, node) {
if ((memcmp(tmp->subsys_id, subsys_id, SUBSYS_ID_LEN) == 0) &&
(memcmp(tmp->slot_id, slot_id, SLOT_ID_LEN) == 0)) {
kref_get(&tmp->kref);
spin_unlock(&list_lock);
return tmp;
}
}
ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
if (!ctlr)
goto done;
/* initialize fields of controller */
memcpy(ctlr->subsys_id, subsys_id, SUBSYS_ID_LEN);
memcpy(ctlr->slot_id, slot_id, SLOT_ID_LEN);
kref_init(&ctlr->kref);
spin_lock_init(&ctlr->lock);
ctlr->submitted = 0;
ctlr->use_10_ms = -1;
INIT_LIST_HEAD(&ctlr->cmd_list);
list_add(&ctlr->node, &ctlr_list);
done:
spin_unlock(&list_lock);
return ctlr;
}
static void c4_endio(struct request *req, int error)
{
struct rdac_handler *h = req->end_io_data;
struct c4_inquiry *sp;
if (had_failures(req, error)) {
dm_pg_init_complete(h->path, MP_FAIL_PATH);
goto done;
}
sp = &h->inq.c4;
h->ctlr = get_controller(sp->subsys_id, sp->slot_id);
if (h->ctlr) {
h->cmd_to_send = SEND_C9_INQUIRY;
queue_work(rdac_wkqd, &h->work);
} else
dm_pg_init_complete(h->path, MP_FAIL_PATH);
done:
__blk_put_request(req->q, req);
}
static void c2_endio(struct request *req, int error)
{
struct rdac_handler *h = req->end_io_data;
struct c2_inquiry *sp;
if (had_failures(req, error)) {
dm_pg_init_complete(h->path, MP_FAIL_PATH);
goto done;
}
sp = &h->inq.c2;
/* If more than MODE6_MAX_LUN luns are supported, use mode select 10 */
if (sp->max_lun_supported >= MODE6_MAX_LUN)
h->ctlr->use_10_ms = 1;
else
h->ctlr->use_10_ms = 0;
h->cmd_to_send = SEND_MODE_SELECT;
queue_work(rdac_wkqd, &h->work);
done:
__blk_put_request(req->q, req);
}
static void c9_endio(struct request *req, int error)
{
struct rdac_handler *h = req->end_io_data;
struct c9_inquiry *sp;
if (had_failures(req, error)) {
dm_pg_init_complete(h->path, MP_FAIL_PATH);
goto done;
}
/* We need to look at the sense keys here to take clear action.
* For now simple logic: If the host is in AVT mode or if controller
* owns the lun, return dm_pg_init_complete(), otherwise submit
* MODE SELECT.
*/
sp = &h->inq.c9;
/* If in AVT mode, return success */
if ((sp->avte_cvp >> 7) == 0x1) {
dm_pg_init_complete(h->path, 0);
goto done;
}
/* If the controller on this path owns the LUN, return success */
if (sp->avte_cvp & 0x1) {
dm_pg_init_complete(h->path, 0);
goto done;
}
if (h->ctlr) {
if (h->ctlr->use_10_ms == -1)
h->cmd_to_send = SEND_C2_INQUIRY;
else
h->cmd_to_send = SEND_MODE_SELECT;
} else
h->cmd_to_send = SEND_C4_INQUIRY;
queue_work(rdac_wkqd, &h->work);
done:
__blk_put_request(req->q, req);
}
static void c8_endio(struct request *req, int error)
{
struct rdac_handler *h = req->end_io_data;
struct c8_inquiry *sp;
if (had_failures(req, error)) {
dm_pg_init_complete(h->path, MP_FAIL_PATH);
goto done;
}
/* We need to look at the sense keys here to take clear action.
* For now simple logic: Get the lun from the inquiry page.
*/
sp = &h->inq.c8;
h->lun = sp->lun[7]; /* currently it uses only one byte */
h->cmd_to_send = SEND_C9_INQUIRY;
queue_work(rdac_wkqd, &h->work);
done:
__blk_put_request(req->q, req);
}
static void submit_inquiry(struct rdac_handler *h, int page_code,
unsigned int len, rq_end_io_fn endio)
{
struct request *rq;
struct request_queue *q = bdev_get_queue(h->path->dev->bdev);
if (!q)
goto fail_path;
rq = get_rdac_req(h, &h->inq, len, READ);
if (!rq)
goto fail_path;
/* Prepare the command. */
rq->cmd[0] = INQUIRY;
rq->cmd[1] = 1;
rq->cmd[2] = page_code;
rq->cmd[4] = len;
rq->cmd_len = COMMAND_SIZE(INQUIRY);
blk_execute_rq_nowait(q, NULL, rq, 1, endio);
return;
fail_path:
dm_pg_init_complete(h->path, MP_FAIL_PATH);
}
static void service_wkq(struct work_struct *work)
{
struct rdac_handler *h = container_of(work, struct rdac_handler, work);
switch (h->cmd_to_send) {
case SEND_C2_INQUIRY:
submit_inquiry(h, 0xC2, sizeof(struct c2_inquiry), c2_endio);
break;
case SEND_C4_INQUIRY:
submit_inquiry(h, 0xC4, sizeof(struct c4_inquiry), c4_endio);
break;
case SEND_C8_INQUIRY:
submit_inquiry(h, 0xC8, sizeof(struct c8_inquiry), c8_endio);
break;
case SEND_C9_INQUIRY:
submit_inquiry(h, 0xC9, sizeof(struct c9_inquiry), c9_endio);
break;
case SEND_MODE_SELECT:
submit_mode_select(h);
break;
default:
BUG();
}
}
/*
* only support subpage2c until we confirm that this is just a matter of
* of updating firmware or not, and RDAC (basic AVT works already) for now
* but we can add these in in when we get time and testers
*/
static int rdac_create(struct hw_handler *hwh, unsigned argc, char **argv)
{
struct rdac_handler *h;
unsigned timeout;
if (argc == 0) {
/* No arguments: use defaults */
timeout = RDAC_FAILOVER_TIMEOUT;
} else if (argc != 1) {
DMWARN("incorrect number of arguments");
return -EINVAL;
} else {
if (sscanf(argv[1], "%u", &timeout) != 1) {
DMWARN("invalid timeout value");
return -EINVAL;
}
}
h = kzalloc(sizeof(*h), GFP_KERNEL);
if (!h)
return -ENOMEM;
hwh->context = h;
h->timeout = timeout;
h->lun = UNINITIALIZED_LUN;
INIT_WORK(&h->work, service_wkq);
DMWARN("using RDAC command with timeout %u", h->timeout);
return 0;
}
static void rdac_destroy(struct hw_handler *hwh)
{
struct rdac_handler *h = hwh->context;
if (h->ctlr)
kref_put(&h->ctlr->kref, release_ctlr);
kfree(h);
hwh->context = NULL;
}
static unsigned rdac_error(struct hw_handler *hwh, struct bio *bio)
{
/* Try default handler */
return dm_scsi_err_handler(hwh, bio);
}
static void rdac_pg_init(struct hw_handler *hwh, unsigned bypassed,
struct dm_path *path)
{
struct rdac_handler *h = hwh->context;
h->path = path;
switch (h->lun) {
case UNINITIALIZED_LUN:
submit_inquiry(h, 0xC8, sizeof(struct c8_inquiry), c8_endio);
break;
default:
submit_inquiry(h, 0xC9, sizeof(struct c9_inquiry), c9_endio);
}
}
static struct hw_handler_type rdac_handler = {
.name = RDAC_DM_HWH_NAME,
.module = THIS_MODULE,
.create = rdac_create,
.destroy = rdac_destroy,
.pg_init = rdac_pg_init,
.error = rdac_error,
};
static int __init rdac_init(void)
{
int r;
rdac_wkqd = create_singlethread_workqueue("rdac_wkqd");
if (!rdac_wkqd) {
DMERR("Failed to create workqueue rdac_wkqd.");
return -ENOMEM;
}
r = dm_register_hw_handler(&rdac_handler);
if (r < 0) {
DMERR("%s: register failed %d", RDAC_DM_HWH_NAME, r);
destroy_workqueue(rdac_wkqd);
return r;
}
DMINFO("%s: version %s loaded", RDAC_DM_HWH_NAME, RDAC_DM_HWH_VER);
return 0;
}
static void __exit rdac_exit(void)
{
int r = dm_unregister_hw_handler(&rdac_handler);
destroy_workqueue(rdac_wkqd);
if (r < 0)
DMERR("%s: unregister failed %d", RDAC_DM_HWH_NAME, r);
}
module_init(rdac_init);
module_exit(rdac_exit);
MODULE_DESCRIPTION("DM Multipath LSI/Engenio RDAC support");
MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
MODULE_LICENSE("GPL");
MODULE_VERSION(RDAC_DM_HWH_VER);
