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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Basic HP/COMPAQ MSA 1000 support. This is only needed if your HW cannot be4 * upgraded.5 *6 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.7 * Copyright (C) 2006 Mike Christie8 * Copyright (C) 2008 Hannes Reinecke <hare@suse.de>9 */10 11#include <linux/slab.h>12#include <linux/module.h>13#include <scsi/scsi.h>14#include <scsi/scsi_dbg.h>15#include <scsi/scsi_eh.h>16#include <scsi/scsi_dh.h>17 18#define HP_SW_NAME "hp_sw"19 20#define HP_SW_TIMEOUT (60 * HZ)21#define HP_SW_RETRIES 322 23#define HP_SW_PATH_UNINITIALIZED -124#define HP_SW_PATH_ACTIVE 025#define HP_SW_PATH_PASSIVE 126 27struct hp_sw_dh_data {28 int path_state;29 int retries;30 int retry_cnt;31 struct scsi_device *sdev;32};33 34static int hp_sw_start_stop(struct hp_sw_dh_data *);35 36/*37 * tur_done - Handle TEST UNIT READY return status38 * @sdev: sdev the command has been sent to39 * @errors: blk error code40 *41 * Returns SCSI_DH_DEV_OFFLINED if the sdev is on the passive path42 */43static int tur_done(struct scsi_device *sdev, struct hp_sw_dh_data *h,44 struct scsi_sense_hdr *sshdr)45{46 int ret = SCSI_DH_IO;47 48 switch (sshdr->sense_key) {49 case NOT_READY:50 if (sshdr->asc == 0x04 && sshdr->ascq == 2) {51 /*52 * LUN not ready - Initialization command required53 *54 * This is the passive path55 */56 h->path_state = HP_SW_PATH_PASSIVE;57 ret = SCSI_DH_OK;58 break;59 }60 fallthrough;61 default:62 sdev_printk(KERN_WARNING, sdev,63 "%s: sending tur failed, sense %x/%x/%x\n",64 HP_SW_NAME, sshdr->sense_key, sshdr->asc,65 sshdr->ascq);66 break;67 }68 return ret;69}70 71/*72 * hp_sw_tur - Send TEST UNIT READY73 * @sdev: sdev command should be sent to74 *75 * Use the TEST UNIT READY command to determine76 * the path state.77 */78static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)79{80 unsigned char cmd[6] = { TEST_UNIT_READY };81 struct scsi_sense_hdr sshdr;82 int ret, res;83 blk_opf_t opf = REQ_OP_DRV_IN | REQ_FAILFAST_DEV |84 REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER;85 struct scsi_failure failure_defs[] = {86 {87 .sense = UNIT_ATTENTION,88 .asc = SCMD_FAILURE_ASC_ANY,89 .ascq = SCMD_FAILURE_ASCQ_ANY,90 .allowed = SCMD_FAILURE_NO_LIMIT,91 .result = SAM_STAT_CHECK_CONDITION,92 },93 {}94 };95 struct scsi_failures failures = {96 .failure_definitions = failure_defs,97 };98 const struct scsi_exec_args exec_args = {99 .sshdr = &sshdr,100 .failures = &failures,101 };102 103 res = scsi_execute_cmd(sdev, cmd, opf, NULL, 0, HP_SW_TIMEOUT,104 HP_SW_RETRIES, &exec_args);105 if (res > 0 && scsi_sense_valid(&sshdr)) {106 ret = tur_done(sdev, h, &sshdr);107 } else if (res == 0) {108 h->path_state = HP_SW_PATH_ACTIVE;109 ret = SCSI_DH_OK;110 } else {111 sdev_printk(KERN_WARNING, sdev,112 "%s: sending tur failed with %x\n",113 HP_SW_NAME, res);114 ret = SCSI_DH_IO;115 }116 117 return ret;118}119 120/*121 * hp_sw_start_stop - Send START STOP UNIT command122 * @sdev: sdev command should be sent to123 *124 * Sending START STOP UNIT activates the SP.125 */126static int hp_sw_start_stop(struct hp_sw_dh_data *h)127{128 unsigned char cmd[6] = { START_STOP, 0, 0, 0, 1, 0 };129 struct scsi_sense_hdr sshdr;130 struct scsi_device *sdev = h->sdev;131 int res, rc;132 blk_opf_t opf = REQ_OP_DRV_IN | REQ_FAILFAST_DEV |133 REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER;134 struct scsi_failure failure_defs[] = {135 {136 /*137 * LUN not ready - manual intervention required138 *139 * Switch-over in progress, retry.140 */141 .sense = NOT_READY,142 .asc = 0x04,143 .ascq = 0x03,144 .allowed = HP_SW_RETRIES,145 .result = SAM_STAT_CHECK_CONDITION,146 },147 {}148 };149 struct scsi_failures failures = {150 .failure_definitions = failure_defs,151 };152 const struct scsi_exec_args exec_args = {153 .sshdr = &sshdr,154 .failures = &failures,155 };156 157 res = scsi_execute_cmd(sdev, cmd, opf, NULL, 0, HP_SW_TIMEOUT,158 HP_SW_RETRIES, &exec_args);159 if (!res) {160 return SCSI_DH_OK;161 } else if (res < 0 || !scsi_sense_valid(&sshdr)) {162 sdev_printk(KERN_WARNING, sdev,163 "%s: sending start_stop_unit failed, "164 "no sense available\n", HP_SW_NAME);165 return SCSI_DH_IO;166 }167 168 switch (sshdr.sense_key) {169 case NOT_READY:170 if (sshdr.asc == 0x04 && sshdr.ascq == 3) {171 rc = SCSI_DH_RETRY;172 break;173 }174 fallthrough;175 default:176 sdev_printk(KERN_WARNING, sdev,177 "%s: sending start_stop_unit failed, "178 "sense %x/%x/%x\n", HP_SW_NAME,179 sshdr.sense_key, sshdr.asc, sshdr.ascq);180 rc = SCSI_DH_IO;181 }182 183 return rc;184}185 186static blk_status_t hp_sw_prep_fn(struct scsi_device *sdev, struct request *req)187{188 struct hp_sw_dh_data *h = sdev->handler_data;189 190 if (h->path_state != HP_SW_PATH_ACTIVE) {191 req->rq_flags |= RQF_QUIET;192 return BLK_STS_IOERR;193 }194 195 return BLK_STS_OK;196}197 198/*199 * hp_sw_activate - Activate a path200 * @sdev: sdev on the path to be activated201 *202 * The HP Active/Passive firmware is pretty simple;203 * the passive path reports NOT READY with sense codes204 * 0x04/0x02; a START STOP UNIT command will then205 * activate the passive path (and deactivate the206 * previously active one).207 */208static int hp_sw_activate(struct scsi_device *sdev,209 activate_complete fn, void *data)210{211 int ret = SCSI_DH_OK;212 struct hp_sw_dh_data *h = sdev->handler_data;213 214 ret = hp_sw_tur(sdev, h);215 216 if (ret == SCSI_DH_OK && h->path_state == HP_SW_PATH_PASSIVE)217 ret = hp_sw_start_stop(h);218 219 if (fn)220 fn(data, ret);221 return 0;222}223 224static int hp_sw_bus_attach(struct scsi_device *sdev)225{226 struct hp_sw_dh_data *h;227 int ret;228 229 h = kzalloc(sizeof(*h), GFP_KERNEL);230 if (!h)231 return SCSI_DH_NOMEM;232 h->path_state = HP_SW_PATH_UNINITIALIZED;233 h->retries = HP_SW_RETRIES;234 h->sdev = sdev;235 236 ret = hp_sw_tur(sdev, h);237 if (ret != SCSI_DH_OK)238 goto failed;239 if (h->path_state == HP_SW_PATH_UNINITIALIZED) {240 ret = SCSI_DH_NOSYS;241 goto failed;242 }243 244 sdev_printk(KERN_INFO, sdev, "%s: attached to %s path\n",245 HP_SW_NAME, h->path_state == HP_SW_PATH_ACTIVE?246 "active":"passive");247 248 sdev->handler_data = h;249 return SCSI_DH_OK;250failed:251 kfree(h);252 return ret;253}254 255static void hp_sw_bus_detach( struct scsi_device *sdev )256{257 kfree(sdev->handler_data);258 sdev->handler_data = NULL;259}260 261static struct scsi_device_handler hp_sw_dh = {262 .name = HP_SW_NAME,263 .module = THIS_MODULE,264 .attach = hp_sw_bus_attach,265 .detach = hp_sw_bus_detach,266 .activate = hp_sw_activate,267 .prep_fn = hp_sw_prep_fn,268};269 270static int __init hp_sw_init(void)271{272 return scsi_register_device_handler(&hp_sw_dh);273}274 275static void __exit hp_sw_exit(void)276{277 scsi_unregister_device_handler(&hp_sw_dh);278}279 280module_init(hp_sw_init);281module_exit(hp_sw_exit);282 283MODULE_DESCRIPTION("HP Active/Passive driver");284MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu");285MODULE_LICENSE("GPL");286