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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2012-2022, Intel Corporation. All rights reserved.4 * Intel Management Engine Interface (Intel MEI) Linux driver5 */6 7#include <linux/export.h>8#include <linux/sched.h>9#include <linux/wait.h>10#include <linux/delay.h>11 12#include <linux/mei.h>13 14#include "mei_dev.h"15#include "hbm.h"16#include "client.h"17 18const char *mei_dev_state_str(int state)19{20#define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state21 switch (state) {22 MEI_DEV_STATE(INITIALIZING);23 MEI_DEV_STATE(INIT_CLIENTS);24 MEI_DEV_STATE(ENABLED);25 MEI_DEV_STATE(RESETTING);26 MEI_DEV_STATE(DISABLED);27 MEI_DEV_STATE(POWERING_DOWN);28 MEI_DEV_STATE(POWER_DOWN);29 MEI_DEV_STATE(POWER_UP);30 default:31 return "unknown";32 }33#undef MEI_DEV_STATE34}35 36const char *mei_pg_state_str(enum mei_pg_state state)37{38#define MEI_PG_STATE(state) case MEI_PG_##state: return #state39 switch (state) {40 MEI_PG_STATE(OFF);41 MEI_PG_STATE(ON);42 default:43 return "unknown";44 }45#undef MEI_PG_STATE46}47 48/**49 * mei_fw_status2str - convert fw status registers to printable string50 *51 * @fw_status: firmware status52 * @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ53 * @len: buffer len must be >= MEI_FW_STATUS_STR_SZ54 *55 * Return: number of bytes written or -EINVAL if buffer is to small56 */57ssize_t mei_fw_status2str(struct mei_fw_status *fw_status,58 char *buf, size_t len)59{60 ssize_t cnt = 0;61 int i;62 63 buf[0] = '\0';64 65 if (len < MEI_FW_STATUS_STR_SZ)66 return -EINVAL;67 68 for (i = 0; i < fw_status->count; i++)69 cnt += scnprintf(buf + cnt, len - cnt, "%08X ",70 fw_status->status[i]);71 72 /* drop last space */73 buf[cnt] = '\0';74 return cnt;75}76EXPORT_SYMBOL_GPL(mei_fw_status2str);77 78/**79 * mei_cancel_work - Cancel mei background jobs80 *81 * @dev: the device structure82 */83void mei_cancel_work(struct mei_device *dev)84{85 cancel_work_sync(&dev->reset_work);86 cancel_work_sync(&dev->bus_rescan_work);87 88 cancel_delayed_work_sync(&dev->timer_work);89}90EXPORT_SYMBOL_GPL(mei_cancel_work);91 92static void mei_save_fw_status(struct mei_device *dev)93{94 struct mei_fw_status fw_status;95 int ret;96 97 ret = mei_fw_status(dev, &fw_status);98 if (ret) {99 dev_err(dev->dev, "failed to read firmware status: %d\n", ret);100 return;101 }102 103 dev->saved_dev_state = dev->dev_state;104 dev->saved_fw_status_flag = true;105 memcpy(&dev->saved_fw_status, &fw_status, sizeof(fw_status));106}107 108/**109 * mei_reset - resets host and fw.110 *111 * @dev: the device structure112 *113 * Return: 0 on success or < 0 if the reset hasn't succeeded114 */115int mei_reset(struct mei_device *dev)116{117 enum mei_dev_state state = dev->dev_state;118 bool interrupts_enabled;119 int ret;120 121 if (state != MEI_DEV_INITIALIZING &&122 state != MEI_DEV_DISABLED &&123 state != MEI_DEV_POWER_DOWN &&124 state != MEI_DEV_POWER_UP) {125 char fw_sts_str[MEI_FW_STATUS_STR_SZ];126 127 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);128 if (kind_is_gsc(dev) || kind_is_gscfi(dev)) {129 dev_dbg(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",130 mei_dev_state_str(state), fw_sts_str);131 mei_save_fw_status(dev);132 } else {133 dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",134 mei_dev_state_str(state), fw_sts_str);135 }136 }137 138 mei_clear_interrupts(dev);139 140 /* we're already in reset, cancel the init timer141 * if the reset was called due the hbm protocol error142 * we need to call it before hw start143 * so the hbm watchdog won't kick in144 */145 mei_hbm_idle(dev);146 147 /* enter reset flow */148 interrupts_enabled = state != MEI_DEV_POWER_DOWN;149 mei_set_devstate(dev, MEI_DEV_RESETTING);150 151 dev->reset_count++;152 if (dev->reset_count > MEI_MAX_CONSEC_RESET) {153 dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");154 mei_set_devstate(dev, MEI_DEV_DISABLED);155 return -ENODEV;156 }157 158 ret = mei_hw_reset(dev, interrupts_enabled);159 /* fall through and remove the sw state even if hw reset has failed */160 161 /* no need to clean up software state in case of power up */162 if (state != MEI_DEV_INITIALIZING && state != MEI_DEV_POWER_UP)163 mei_cl_all_disconnect(dev);164 165 mei_hbm_reset(dev);166 167 /* clean stale FW version */168 dev->fw_ver_received = 0;169 170 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));171 172 if (ret) {173 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);174 return ret;175 }176 177 if (state == MEI_DEV_POWER_DOWN) {178 dev_dbg(dev->dev, "powering down: end of reset\n");179 mei_set_devstate(dev, MEI_DEV_DISABLED);180 return 0;181 }182 183 ret = mei_hw_start(dev);184 if (ret) {185 char fw_sts_str[MEI_FW_STATUS_STR_SZ];186 187 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);188 dev_err(dev->dev, "hw_start failed ret = %d fw status = %s\n", ret, fw_sts_str);189 return ret;190 }191 192 if (dev->dev_state != MEI_DEV_RESETTING) {193 dev_dbg(dev->dev, "wrong state = %d on link start\n", dev->dev_state);194 return 0;195 }196 197 dev_dbg(dev->dev, "link is established start sending messages.\n");198 199 mei_set_devstate(dev, MEI_DEV_INIT_CLIENTS);200 ret = mei_hbm_start_req(dev);201 if (ret) {202 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);203 mei_set_devstate(dev, MEI_DEV_RESETTING);204 return ret;205 }206 207 return 0;208}209EXPORT_SYMBOL_GPL(mei_reset);210 211/**212 * mei_start - initializes host and fw to start work.213 *214 * @dev: the device structure215 *216 * Return: 0 on success, <0 on failure.217 */218int mei_start(struct mei_device *dev)219{220 int ret;221 222 mutex_lock(&dev->device_lock);223 224 /* acknowledge interrupt and stop interrupts */225 mei_clear_interrupts(dev);226 227 ret = mei_hw_config(dev);228 if (ret)229 goto err;230 231 dev_dbg(dev->dev, "reset in start the mei device.\n");232 233 dev->reset_count = 0;234 do {235 mei_set_devstate(dev, MEI_DEV_INITIALIZING);236 ret = mei_reset(dev);237 238 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {239 dev_err(dev->dev, "reset failed ret = %d", ret);240 goto err;241 }242 } while (ret);243 244 if (mei_hbm_start_wait(dev)) {245 dev_err(dev->dev, "HBM haven't started");246 goto err;247 }248 249 if (!mei_hbm_version_is_supported(dev)) {250 dev_dbg(dev->dev, "MEI start failed.\n");251 goto err;252 }253 254 dev_dbg(dev->dev, "link layer has been established.\n");255 256 mutex_unlock(&dev->device_lock);257 return 0;258err:259 dev_err(dev->dev, "link layer initialization failed.\n");260 mei_set_devstate(dev, MEI_DEV_DISABLED);261 mutex_unlock(&dev->device_lock);262 return -ENODEV;263}264EXPORT_SYMBOL_GPL(mei_start);265 266/**267 * mei_restart - restart device after suspend268 *269 * @dev: the device structure270 *271 * Return: 0 on success or -ENODEV if the restart hasn't succeeded272 */273int mei_restart(struct mei_device *dev)274{275 int err;276 277 mutex_lock(&dev->device_lock);278 279 mei_set_devstate(dev, MEI_DEV_POWER_UP);280 dev->reset_count = 0;281 282 err = mei_reset(dev);283 284 mutex_unlock(&dev->device_lock);285 286 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {287 dev_err(dev->dev, "device disabled = %d\n", err);288 return -ENODEV;289 }290 291 /* try to start again */292 if (err)293 schedule_work(&dev->reset_work);294 295 296 return 0;297}298EXPORT_SYMBOL_GPL(mei_restart);299 300static void mei_reset_work(struct work_struct *work)301{302 struct mei_device *dev =303 container_of(work, struct mei_device, reset_work);304 int ret;305 306 mei_clear_interrupts(dev);307 mei_synchronize_irq(dev);308 309 mutex_lock(&dev->device_lock);310 311 ret = mei_reset(dev);312 313 mutex_unlock(&dev->device_lock);314 315 if (dev->dev_state == MEI_DEV_DISABLED) {316 dev_err(dev->dev, "device disabled = %d\n", ret);317 return;318 }319 320 /* retry reset in case of failure */321 if (ret)322 schedule_work(&dev->reset_work);323}324 325void mei_stop(struct mei_device *dev)326{327 dev_dbg(dev->dev, "stopping the device.\n");328 329 mutex_lock(&dev->device_lock);330 mei_set_devstate(dev, MEI_DEV_POWERING_DOWN);331 mutex_unlock(&dev->device_lock);332 mei_cl_bus_remove_devices(dev);333 mutex_lock(&dev->device_lock);334 mei_set_devstate(dev, MEI_DEV_POWER_DOWN);335 mutex_unlock(&dev->device_lock);336 337 mei_cancel_work(dev);338 339 mei_clear_interrupts(dev);340 mei_synchronize_irq(dev);341 /* to catch HW-initiated reset */342 mei_cancel_work(dev);343 344 mutex_lock(&dev->device_lock);345 346 mei_reset(dev);347 /* move device to disabled state unconditionally */348 mei_set_devstate(dev, MEI_DEV_DISABLED);349 350 mutex_unlock(&dev->device_lock);351}352EXPORT_SYMBOL_GPL(mei_stop);353 354/**355 * mei_write_is_idle - check if the write queues are idle356 *357 * @dev: the device structure358 *359 * Return: true of there is no pending write360 */361bool mei_write_is_idle(struct mei_device *dev)362{363 bool idle = (dev->dev_state == MEI_DEV_ENABLED &&364 list_empty(&dev->ctrl_wr_list) &&365 list_empty(&dev->write_list) &&366 list_empty(&dev->write_waiting_list));367 368 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n",369 idle,370 mei_dev_state_str(dev->dev_state),371 list_empty(&dev->ctrl_wr_list),372 list_empty(&dev->write_list),373 list_empty(&dev->write_waiting_list));374 375 return idle;376}377EXPORT_SYMBOL_GPL(mei_write_is_idle);378 379/**380 * mei_device_init - initialize mei_device structure381 *382 * @dev: the mei device383 * @device: the device structure384 * @slow_fw: configure longer timeouts as FW is slow385 * @hw_ops: hw operations386 */387void mei_device_init(struct mei_device *dev,388 struct device *device,389 bool slow_fw,390 const struct mei_hw_ops *hw_ops)391{392 /* setup our list array */393 INIT_LIST_HEAD(&dev->file_list);394 INIT_LIST_HEAD(&dev->device_list);395 INIT_LIST_HEAD(&dev->me_clients);396 mutex_init(&dev->device_lock);397 init_rwsem(&dev->me_clients_rwsem);398 mutex_init(&dev->cl_bus_lock);399 init_waitqueue_head(&dev->wait_hw_ready);400 init_waitqueue_head(&dev->wait_pg);401 init_waitqueue_head(&dev->wait_hbm_start);402 dev->dev_state = MEI_DEV_INITIALIZING;403 dev->reset_count = 0;404 405 INIT_LIST_HEAD(&dev->write_list);406 INIT_LIST_HEAD(&dev->write_waiting_list);407 INIT_LIST_HEAD(&dev->ctrl_wr_list);408 INIT_LIST_HEAD(&dev->ctrl_rd_list);409 dev->tx_queue_limit = MEI_TX_QUEUE_LIMIT_DEFAULT;410 411 INIT_DELAYED_WORK(&dev->timer_work, mei_timer);412 INIT_WORK(&dev->reset_work, mei_reset_work);413 INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work);414 415 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);416 dev->open_handle_count = 0;417 418 dev->pxp_mode = MEI_DEV_PXP_DEFAULT;419 dev->gsc_reset_to_pxp = MEI_DEV_RESET_TO_PXP_DEFAULT;420 421 /*422 * Reserving the first client ID423 * 0: Reserved for MEI Bus Message communications424 */425 bitmap_set(dev->host_clients_map, 0, 1);426 427 dev->pg_event = MEI_PG_EVENT_IDLE;428 dev->ops = hw_ops;429 dev->dev = device;430 431 dev->timeouts.hw_ready = mei_secs_to_jiffies(MEI_HW_READY_TIMEOUT);432 dev->timeouts.connect = MEI_CONNECT_TIMEOUT;433 dev->timeouts.client_init = MEI_CLIENTS_INIT_TIMEOUT;434 dev->timeouts.pgi = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);435 dev->timeouts.d0i3 = mei_secs_to_jiffies(MEI_D0I3_TIMEOUT);436 if (slow_fw) {437 dev->timeouts.cl_connect = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT_SLOW);438 dev->timeouts.hbm = mei_secs_to_jiffies(MEI_HBM_TIMEOUT_SLOW);439 dev->timeouts.mkhi_recv = msecs_to_jiffies(MKHI_RCV_TIMEOUT_SLOW);440 } else {441 dev->timeouts.cl_connect = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT);442 dev->timeouts.hbm = mei_secs_to_jiffies(MEI_HBM_TIMEOUT);443 dev->timeouts.mkhi_recv = msecs_to_jiffies(MKHI_RCV_TIMEOUT);444 }445}446EXPORT_SYMBOL_GPL(mei_device_init);447 448