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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *  linux/drivers/mmc/core/core.c
  *
  *  Copyright (C) 2003-2004 Russell King, All Rights Reserved.
  *  SD support Copyright (C) 2004 Ian Molton, All Rights Reserved.
  *  Copyright (C) 2005-2008 Pierre Ossman, All Rights Reserved.
  *  MMCv4 support Copyright (C) 2006 Philip Langdale, All Rights Reserved.
  */
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/completion.h>
 #include <linux/device.h>
 #include <linux/delay.h>
 #include <linux/pagemap.h>
 #include <linux/err.h>
 #include <linux/leds.h>
 #include <linux/scatterlist.h>
 #include <linux/log2.h>
 #include <linux/pm_runtime.h>
 #include <linux/pm_wakeup.h>
 #include <linux/suspend.h>
 #include <linux/fault-inject.h>
 #include <linux/random.h>
 #include <linux/slab.h>
 #include <linux/of.h>
 
 #include <linux/mmc/card.h>
 #include <linux/mmc/host.h>
 #include <linux/mmc/mmc.h>
 #include <linux/mmc/sd.h>
 #include <linux/mmc/slot-gpio.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/mmc.h>
 
 #include "core.h"
 #include "card.h"
 #include "crypto.h"
 #include "bus.h"
 #include "host.h"
 #include "sdio_bus.h"
 #include "pwrseq.h"
 
 #include "mmc_ops.h"
 #include "sd_ops.h"
 #include "sdio_ops.h"
 
 /* The max erase timeout, used when host->max_busy_timeout isn't specified */
 #define MMC_ERASE_TIMEOUT_MS    (60 * 1000) /* 60 s */
 #define SD_DISCARD_TIMEOUT_MS   (250)
 
 static const unsigned freqs[] = { 400000, 300000, 200000, 100000 };
 
 /*
  * Enabling software CRCs on the data blocks can be a significant (30%)
  * performance cost, and for other reasons may not always be desired.
  * So we allow it it to be disabled.
  */
 bool use_spi_crc = 1;
 module_param(use_spi_crc, bool, 0);
 
 static int mmc_schedule_delayed_work(struct delayed_work *work,
                      unsigned long delay)
 {
     /*
      * We use the system_freezable_wq, because of two reasons.
      * First, it allows several works (not the same work item) to be
      * executed simultaneously. Second, the queue becomes frozen when
      * userspace becomes frozen during system PM.
      */
     return queue_delayed_work(system_freezable_wq, work, delay);
 }
 
 #ifdef CONFIG_FAIL_MMC_REQUEST
 
 /*
  * Internal function. Inject random data errors.
  * If mmc_data is NULL no errors are injected.
  */
 static void mmc_should_fail_request(struct mmc_host *host,
                     struct mmc_request *mrq)
 {
     struct mmc_command *cmd = mrq->cmd;
     struct mmc_data *data = mrq->data;
     static const int data_errors[] = {
         -ETIMEDOUT,
         -EILSEQ,
         -EIO,
     };
 
     if (!data)
         return;
 
     if ((cmd && cmd->error) || data->error ||
         !should_fail(&host->fail_mmc_request, data->blksz * data->blocks))
         return;
 
     data->error = data_errors[prandom_u32() % ARRAY_SIZE(data_errors)];
     data->bytes_xfered = (prandom_u32() % (data->bytes_xfered >> 9)) << 9;
 }
 
 #else /* CONFIG_FAIL_MMC_REQUEST */
 
 static inline void mmc_should_fail_request(struct mmc_host *host,
                        struct mmc_request *mrq)
 {
 }
 
 #endif /* CONFIG_FAIL_MMC_REQUEST */
 
 static inline void mmc_complete_cmd(struct mmc_request *mrq)
 {
     if (mrq->cap_cmd_during_tfr && !completion_done(&mrq->cmd_completion))
         complete_all(&mrq->cmd_completion);
 }
 
 void mmc_command_done(struct mmc_host *host, struct mmc_request *mrq)
 {
     if (!mrq->cap_cmd_during_tfr)
         return;
 
     mmc_complete_cmd(mrq);
 
     pr_debug("%s: cmd done, tfr ongoing (CMD%u)\n",
          mmc_hostname(host), mrq->cmd->opcode);
 }
 EXPORT_SYMBOL(mmc_command_done);
 
 /**
  *  mmc_request_done - finish processing an MMC request
  *  @host: MMC host which completed request
  *  @mrq: MMC request which request
  *
  *  MMC drivers should call this function when they have completed
  *  their processing of a request.
  */
 void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
 {
     struct mmc_command *cmd = mrq->cmd;
     int err = cmd->error;
 
     /* Flag re-tuning needed on CRC errors */
     if (cmd->opcode != MMC_SEND_TUNING_BLOCK &&
         cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200 &&
         !host->retune_crc_disable &&
         (err == -EILSEQ || (mrq->sbc && mrq->sbc->error == -EILSEQ) ||
         (mrq->data && mrq->data->error == -EILSEQ) ||
         (mrq->stop && mrq->stop->error == -EILSEQ)))
         mmc_retune_needed(host);
 
     if (err && cmd->retries && mmc_host_is_spi(host)) {
         if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND)
             cmd->retries = 0;
     }
 
     if (host->ongoing_mrq == mrq)
         host->ongoing_mrq = NULL;
 
     mmc_complete_cmd(mrq);
 
     trace_mmc_request_done(host, mrq);
 
     /*
      * We list various conditions for the command to be considered
      * properly done:
      *
      * - There was no error, OK fine then
      * - We are not doing some kind of retry
      * - The card was removed (...so just complete everything no matter
      *   if there are errors or retries)
      */
     if (!err || !cmd->retries || mmc_card_removed(host->card)) {
         mmc_should_fail_request(host, mrq);
 
         if (!host->ongoing_mrq)
             led_trigger_event(host->led, LED_OFF);
 
         if (mrq->sbc) {
             pr_debug("%s: req done <CMD%u>: %d: %08x %08x %08x %08x\n",
                 mmc_hostname(host), mrq->sbc->opcode,
                 mrq->sbc->error,
                 mrq->sbc->resp[0], mrq->sbc->resp[1],
                 mrq->sbc->resp[2], mrq->sbc->resp[3]);
         }
 
         pr_debug("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n",
             mmc_hostname(host), cmd->opcode, err,
             cmd->resp[0], cmd->resp[1],
             cmd->resp[2], cmd->resp[3]);
 
         if (mrq->data) {
             pr_debug("%s:     %d bytes transferred: %d\n",
                 mmc_hostname(host),
                 mrq->data->bytes_xfered, mrq->data->error);
         }
 
         if (mrq->stop) {
             pr_debug("%s:     (CMD%u): %d: %08x %08x %08x %08x\n",
                 mmc_hostname(host), mrq->stop->opcode,
                 mrq->stop->error,
                 mrq->stop->resp[0], mrq->stop->resp[1],
                 mrq->stop->resp[2], mrq->stop->resp[3]);
         }
     }
     /*
      * Request starter must handle retries - see
      * mmc_wait_for_req_done().
      */
     if (mrq->done)
         mrq->done(mrq);
 }
 
 EXPORT_SYMBOL(mmc_request_done);
 
 static void __mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
 {
     int err;
 
     /* Assumes host controller has been runtime resumed by mmc_claim_host */
     err = mmc_retune(host);
     if (err) {
         mrq->cmd->error = err;
         mmc_request_done(host, mrq);
         return;
     }
 
     /*
      * For sdio rw commands we must wait for card busy otherwise some
      * sdio devices won't work properly.
      * And bypass I/O abort, reset and bus suspend operations.
      */
     if (sdio_is_io_busy(mrq->cmd->opcode, mrq->cmd->arg) &&
         host->ops->card_busy) {
         int tries = 500; /* Wait aprox 500ms at maximum */
 
         while (host->ops->card_busy(host) && --tries)
             mmc_delay(1);
 
         if (tries == 0) {
             mrq->cmd->error = -EBUSY;
             mmc_request_done(host, mrq);
             return;
         }
     }
 
     if (mrq->cap_cmd_during_tfr) {
         host->ongoing_mrq = mrq;
         /*
          * Retry path could come through here without having waiting on
          * cmd_completion, so ensure it is reinitialised.
          */
         reinit_completion(&mrq->cmd_completion);
     }
 
     trace_mmc_request_start(host, mrq);
 
     if (host->cqe_on)
         host->cqe_ops->cqe_off(host);
 
     host->ops->request(host, mrq);
 }
 
 static void mmc_mrq_pr_debug(struct mmc_host *host, struct mmc_request *mrq,
                  bool cqe)
 {
     if (mrq->sbc) {
         pr_debug("<%s: starting CMD%u arg %08x flags %08x>\n",
              mmc_hostname(host), mrq->sbc->opcode,
              mrq->sbc->arg, mrq->sbc->flags);
     }
 
     if (mrq->cmd) {
         pr_debug("%s: starting %sCMD%u arg %08x flags %08x\n",
              mmc_hostname(host), cqe ? "CQE direct " : "",
              mrq->cmd->opcode, mrq->cmd->arg, mrq->cmd->flags);
     } else if (cqe) {
         pr_debug("%s: starting CQE transfer for tag %d blkaddr %u\n",
              mmc_hostname(host), mrq->tag, mrq->data->blk_addr);
     }
 
     if (mrq->data) {
         pr_debug("%s:     blksz %d blocks %d flags %08x "
             "tsac %d ms nsac %d\n",
             mmc_hostname(host), mrq->data->blksz,
             mrq->data->blocks, mrq->data->flags,
             mrq->data->timeout_ns / 1000000,
             mrq->data->timeout_clks);
     }
 
     if (mrq->stop) {
         pr_debug("%s:     CMD%u arg %08x flags %08x\n",
              mmc_hostname(host), mrq->stop->opcode,
              mrq->stop->arg, mrq->stop->flags);
     }
 }
 
 static int mmc_mrq_prep(struct mmc_host *host, struct mmc_request *mrq)
 {
     unsigned int i, sz = 0;
     struct scatterlist *sg;
 
     if (mrq->cmd) {
         mrq->cmd->error = 0;
         mrq->cmd->mrq = mrq;
         mrq->cmd->data = mrq->data;
     }
     if (mrq->sbc) {
         mrq->sbc->error = 0;
         mrq->sbc->mrq = mrq;
     }
     if (mrq->data) {
         if (mrq->data->blksz > host->max_blk_size ||
             mrq->data->blocks > host->max_blk_count ||
             mrq->data->blocks * mrq->data->blksz > host->max_req_size)
             return -EINVAL;
 
         for_each_sg(mrq->data->sg, sg, mrq->data->sg_len, i)
             sz += sg->length;
         if (sz != mrq->data->blocks * mrq->data->blksz)
             return -EINVAL;
 
         mrq->data->error = 0;
         mrq->data->mrq = mrq;
         if (mrq->stop) {
             mrq->data->stop = mrq->stop;
             mrq->stop->error = 0;
             mrq->stop->mrq = mrq;
         }
     }
 
     return 0;
 }
 
 int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
 {
     int err;
 
     init_completion(&mrq->cmd_completion);
 
     mmc_retune_hold(host);
 
     if (mmc_card_removed(host->card))
         return -ENOMEDIUM;
 
     mmc_mrq_pr_debug(host, mrq, false);
 
     WARN_ON(!host->claimed);
 
     err = mmc_mrq_prep(host, mrq);
     if (err)
         return err;
 
     led_trigger_event(host->led, LED_FULL);
     __mmc_start_request(host, mrq);
 
     return 0;
 }
 EXPORT_SYMBOL(mmc_start_request);
 
 static void mmc_wait_done(struct mmc_request *mrq)
 {
     complete(&mrq->completion);
 }
 
 static inline void mmc_wait_ongoing_tfr_cmd(struct mmc_host *host)
 {
     struct mmc_request *ongoing_mrq = READ_ONCE(host->ongoing_mrq);
 
     /*
      * If there is an ongoing transfer, wait for the command line to become
      * available.
      */
     if (ongoing_mrq && !completion_done(&ongoing_mrq->cmd_completion))
         wait_for_completion(&ongoing_mrq->cmd_completion);
 }
 
 static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq)
 {
     int err;
 
     mmc_wait_ongoing_tfr_cmd(host);
 
     init_completion(&mrq->completion);
     mrq->done = mmc_wait_done;
 
     err = mmc_start_request(host, mrq);
     if (err) {
         mrq->cmd->error = err;
         mmc_complete_cmd(mrq);
         complete(&mrq->completion);
     }
 
     return err;
 }
 
 void mmc_wait_for_req_done(struct mmc_host *host, struct mmc_request *mrq)
 {
     struct mmc_command *cmd;
 
     while (1) {
         wait_for_completion(&mrq->completion);
 
         cmd = mrq->cmd;
 
         if (!cmd->error || !cmd->retries ||
             mmc_card_removed(host->card))
             break;
 
         mmc_retune_recheck(host);
 
         pr_debug("%s: req failed (CMD%u): %d, retrying...\n",
              mmc_hostname(host), cmd->opcode, cmd->error);
         cmd->retries--;
         cmd->error = 0;
         __mmc_start_request(host, mrq);
     }
 
     mmc_retune_release(host);
 }
 EXPORT_SYMBOL(mmc_wait_for_req_done);
 
 /*
  * mmc_cqe_start_req - Start a CQE request.
  * @host: MMC host to start the request
  * @mrq: request to start
  *
  * Start the request, re-tuning if needed and it is possible. Returns an error
  * code if the request fails to start or -EBUSY if CQE is busy.
  */
 int mmc_cqe_start_req(struct mmc_host *host, struct mmc_request *mrq)
 {
     int err;
 
     /*
      * CQE cannot process re-tuning commands. Caller must hold retuning
      * while CQE is in use.  Re-tuning can happen here only when CQE has no
      * active requests i.e. this is the first.  Note, re-tuning will call
      * ->cqe_off().
      */
     err = mmc_retune(host);
     if (err)
         goto out_err;
 
     mrq->host = host;
 
     mmc_mrq_pr_debug(host, mrq, true);
 
     err = mmc_mrq_prep(host, mrq);
     if (err)
         goto out_err;
 
     err = host->cqe_ops->cqe_request(host, mrq);
     if (err)
         goto out_err;
 
     trace_mmc_request_start(host, mrq);
 
     return 0;
 
 out_err:
     if (mrq->cmd) {
         pr_debug("%s: failed to start CQE direct CMD%u, error %d\n",
              mmc_hostname(host), mrq->cmd->opcode, err);
     } else {
         pr_debug("%s: failed to start CQE transfer for tag %d, error %d\n",
              mmc_hostname(host), mrq->tag, err);
     }
     return err;
 }
 EXPORT_SYMBOL(mmc_cqe_start_req);
 
 /**
  *  mmc_cqe_request_done - CQE has finished processing an MMC request
  *  @host: MMC host which completed request
  *  @mrq: MMC request which completed
  *
  *  CQE drivers should call this function when they have completed
  *  their processing of a request.
  */
 void mmc_cqe_request_done(struct mmc_host *host, struct mmc_request *mrq)
 {
     mmc_should_fail_request(host, mrq);
 
     /* Flag re-tuning needed on CRC errors */
     if ((mrq->cmd && mrq->cmd->error == -EILSEQ) ||
         (mrq->data && mrq->data->error == -EILSEQ))
         mmc_retune_needed(host);
 
     trace_mmc_request_done(host, mrq);
 
     if (mrq->cmd) {
         pr_debug("%s: CQE req done (direct CMD%u): %d\n",
              mmc_hostname(host), mrq->cmd->opcode, mrq->cmd->error);
     } else {
         pr_debug("%s: CQE transfer done tag %d\n",
              mmc_hostname(host), mrq->tag);
     }
 
     if (mrq->data) {
         pr_debug("%s:     %d bytes transferred: %d\n",
              mmc_hostname(host),
              mrq->data->bytes_xfered, mrq->data->error);
     }
 
     mrq->done(mrq);
 }
 EXPORT_SYMBOL(mmc_cqe_request_done);
 
 /**
  *  mmc_cqe_post_req - CQE post process of a completed MMC request
  *  @host: MMC host
  *  @mrq: MMC request to be processed
  */
 void mmc_cqe_post_req(struct mmc_host *host, struct mmc_request *mrq)
 {
     if (host->cqe_ops->cqe_post_req)
         host->cqe_ops->cqe_post_req(host, mrq);
 }
 EXPORT_SYMBOL(mmc_cqe_post_req);
 
 /* Arbitrary 1 second timeout */
 #define MMC_CQE_RECOVERY_TIMEOUT    1000
 
 /*
  * mmc_cqe_recovery - Recover from CQE errors.
  * @host: MMC host to recover
  *
  * Recovery consists of stopping CQE, stopping eMMC, discarding the queue in
  * in eMMC, and discarding the queue in CQE. CQE must call
  * mmc_cqe_request_done() on all requests. An error is returned if the eMMC
  * fails to discard its queue.
  */
 int mmc_cqe_recovery(struct mmc_host *host)
 {
     struct mmc_command cmd;
     int err;
 
     mmc_retune_hold_now(host);
 
     /*
      * Recovery is expected seldom, if at all, but it reduces performance,
      * so make sure it is not completely silent.
      */
     pr_warn("%s: running CQE recovery\n", mmc_hostname(host));
 
     host->cqe_ops->cqe_recovery_start(host);
 
     memset(&cmd, 0, sizeof(cmd));
     cmd.opcode       = MMC_STOP_TRANSMISSION;
     cmd.flags        = MMC_RSP_R1B | MMC_CMD_AC;
     cmd.flags       &= ~MMC_RSP_CRC; /* Ignore CRC */
     cmd.busy_timeout = MMC_CQE_RECOVERY_TIMEOUT;
     mmc_wait_for_cmd(host, &cmd, 0);
 
     memset(&cmd, 0, sizeof(cmd));
     cmd.opcode       = MMC_CMDQ_TASK_MGMT;
     cmd.arg          = 1; /* Discard entire queue */
     cmd.flags        = MMC_RSP_R1B | MMC_CMD_AC;
     cmd.flags       &= ~MMC_RSP_CRC; /* Ignore CRC */
     cmd.busy_timeout = MMC_CQE_RECOVERY_TIMEOUT;
     err = mmc_wait_for_cmd(host, &cmd, 0);
 
     host->cqe_ops->cqe_recovery_finish(host);
 
     mmc_retune_release(host);
 
     return err;
 }
 EXPORT_SYMBOL(mmc_cqe_recovery);
 
 /**
  *  mmc_is_req_done - Determine if a 'cap_cmd_during_tfr' request is done
  *  @host: MMC host
  *  @mrq: MMC request
  *
  *  mmc_is_req_done() is used with requests that have
  *  mrq->cap_cmd_during_tfr = true. mmc_is_req_done() must be called after
  *  starting a request and before waiting for it to complete. That is,
  *  either in between calls to mmc_start_req(), or after mmc_wait_for_req()
  *  and before mmc_wait_for_req_done(). If it is called at other times the
  *  result is not meaningful.
  */
 bool mmc_is_req_done(struct mmc_host *host, struct mmc_request *mrq)
 {
     return completion_done(&mrq->completion);
 }
 EXPORT_SYMBOL(mmc_is_req_done);
 
 /**
  *  mmc_wait_for_req - start a request and wait for completion
  *  @host: MMC host to start command
  *  @mrq: MMC request to start
  *
  *  Start a new MMC custom command request for a host, and wait
  *  for the command to complete. In the case of 'cap_cmd_during_tfr'
  *  requests, the transfer is ongoing and the caller can issue further
  *  commands that do not use the data lines, and then wait by calling
  *  mmc_wait_for_req_done().
  *  Does not attempt to parse the response.
  */
 void mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq)
 {
     __mmc_start_req(host, mrq);
 
     if (!mrq->cap_cmd_during_tfr)
         mmc_wait_for_req_done(host, mrq);
 }
 EXPORT_SYMBOL(mmc_wait_for_req);
 
 /**
  *  mmc_wait_for_cmd - start a command and wait for completion
  *  @host: MMC host to start command
  *  @cmd: MMC command to start
  *  @retries: maximum number of retries
  *
  *  Start a new MMC command for a host, and wait for the command
  *  to complete.  Return any error that occurred while the command
  *  was executing.  Do not attempt to parse the response.
  */
 int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries)
 {
     struct mmc_request mrq = {};
 
     WARN_ON(!host->claimed);
 
     memset(cmd->resp, 0, sizeof(cmd->resp));
     cmd->retries = retries;
 
     mrq.cmd = cmd;
     cmd->data = NULL;
 
     mmc_wait_for_req(host, &mrq);
 
     return cmd->error;
 }
 
 EXPORT_SYMBOL(mmc_wait_for_cmd);
 
 /**
  *  mmc_set_data_timeout - set the timeout for a data command
  *  @data: data phase for command
  *  @card: the MMC card associated with the data transfer
  *
  *  Computes the data timeout parameters according to the
  *  correct algorithm given the card type.
  */
 void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card)
 {
     unsigned int mult;
 
     /*
      * SDIO cards only define an upper 1 s limit on access.
      */
     if (mmc_card_sdio(card)) {
         data->timeout_ns = 1000000000;
         data->timeout_clks = 0;
         return;
     }
 
     /*
      * SD cards use a 100 multiplier rather than 10
      */
     mult = mmc_card_sd(card) ? 100 : 10;
 
     /*
      * Scale up the multiplier (and therefore the timeout) by
      * the r2w factor for writes.
      */
     if (data->flags & MMC_DATA_WRITE)
         mult <<= card->csd.r2w_factor;
 
     data->timeout_ns = card->csd.taac_ns * mult;
     data->timeout_clks = card->csd.taac_clks * mult;
 
     /*
      * SD cards also have an upper limit on the timeout.
      */
     if (mmc_card_sd(card)) {
         unsigned int timeout_us, limit_us;
 
         timeout_us = data->timeout_ns / 1000;
         if (card->host->ios.clock)
             timeout_us += data->timeout_clks * 1000 /
                 (card->host->ios.clock / 1000);
 
         if (data->flags & MMC_DATA_WRITE)
             /*
              * The MMC spec "It is strongly recommended
              * for hosts to implement more than 500ms
              * timeout value even if the card indicates
              * the 250ms maximum busy length."  Even the
              * previous value of 300ms is known to be
              * insufficient for some cards.
              */
             limit_us = 3000000;
         else
             limit_us = 100000;
 
         /*
          * SDHC cards always use these fixed values.
          */
         if (timeout_us > limit_us) {
             data->timeout_ns = limit_us * 1000;
             data->timeout_clks = 0;
         }
 
         /* assign limit value if invalid */
         if (timeout_us == 0)
             data->timeout_ns = limit_us * 1000;
     }
 
     /*
      * Some cards require longer data read timeout than indicated in CSD.
      * Address this by setting the read timeout to a "reasonably high"
      * value. For the cards tested, 600ms has proven enough. If necessary,
      * this value can be increased if other problematic cards require this.
      */
     if (mmc_card_long_read_time(card) && data->flags & MMC_DATA_READ) {
         data->timeout_ns = 600000000;
         data->timeout_clks = 0;
     }
 
     /*
      * Some cards need very high timeouts if driven in SPI mode.
      * The worst observed timeout was 900ms after writing a
      * continuous stream of data until the internal logic
      * overflowed.
      */
     if (mmc_host_is_spi(card->host)) {
         if (data->flags & MMC_DATA_WRITE) {
             if (data->timeout_ns < 1000000000)
                 data->timeout_ns = 1000000000;  /* 1s */
         } else {
             if (data->timeout_ns < 100000000)
                 data->timeout_ns =  100000000;  /* 100ms */
         }
     }
 }
 EXPORT_SYMBOL(mmc_set_data_timeout);
 
 /*
  * Allow claiming an already claimed host if the context is the same or there is
  * no context but the task is the same.
  */
 static inline bool mmc_ctx_matches(struct mmc_host *host, struct mmc_ctx *ctx,
                    struct task_struct *task)
 {
     return host->claimer == ctx ||
            (!ctx && task && host->claimer->task == task);
 }
 
 static inline void mmc_ctx_set_claimer(struct mmc_host *host,
                        struct mmc_ctx *ctx,
                        struct task_struct *task)
 {
     if (!host->claimer) {
         if (ctx)
             host->claimer = ctx;
         else
             host->claimer = &host->default_ctx;
     }
     if (task)
         host->claimer->task = task;
 }
 
 /**
  *  __mmc_claim_host - exclusively claim a host
  *  @host: mmc host to claim
  *  @ctx: context that claims the host or NULL in which case the default
  *  context will be used
  *  @abort: whether or not the operation should be aborted
  *
  *  Claim a host for a set of operations.  If @abort is non null and
  *  dereference a non-zero value then this will return prematurely with
  *  that non-zero value without acquiring the lock.  Returns zero
  *  with the lock held otherwise.
  */
 int __mmc_claim_host(struct mmc_host *host, struct mmc_ctx *ctx,
              atomic_t *abort)
 {
     struct task_struct *task = ctx ? NULL : current;
     DECLARE_WAITQUEUE(wait, current);
     unsigned long flags;
     int stop;
     bool pm = false;
 
     might_sleep();
 
     add_wait_queue(&host->wq, &wait);
     spin_lock_irqsave(&host->lock, flags);
     while (1) {
         set_current_state(TASK_UNINTERRUPTIBLE);
         stop = abort ? atomic_read(abort) : 0;
         if (stop || !host->claimed || mmc_ctx_matches(host, ctx, task))
             break;
         spin_unlock_irqrestore(&host->lock, flags);
         schedule();
         spin_lock_irqsave(&host->lock, flags);
     }
     set_current_state(TASK_RUNNING);
     if (!stop) {
         host->claimed = 1;
         mmc_ctx_set_claimer(host, ctx, task);
         host->claim_cnt += 1;
         if (host->claim_cnt == 1)
             pm = true;
     } else
         wake_up(&host->wq);
     spin_unlock_irqrestore(&host->lock, flags);
     remove_wait_queue(&host->wq, &wait);
 
     if (pm)
         pm_runtime_get_sync(mmc_dev(host));
 
     return stop;
 }
 EXPORT_SYMBOL(__mmc_claim_host);
 
 /**
  *  mmc_release_host - release a host
  *  @host: mmc host to release
  *
  *  Release a MMC host, allowing others to claim the host
  *  for their operations.
  */
 void mmc_release_host(struct mmc_host *host)
 {
     unsigned long flags;
 
     WARN_ON(!host->claimed);
 
     spin_lock_irqsave(&host->lock, flags);
     if (--host->claim_cnt) {
         /* Release for nested claim */
         spin_unlock_irqrestore(&host->lock, flags);
     } else {
         host->claimed = 0;
         host->claimer->task = NULL;
         host->claimer = NULL;
         spin_unlock_irqrestore(&host->lock, flags);
         wake_up(&host->wq);
         pm_runtime_mark_last_busy(mmc_dev(host));
         if (host->caps & MMC_CAP_SYNC_RUNTIME_PM)
             pm_runtime_put_sync_suspend(mmc_dev(host));
         else
             pm_runtime_put_autosuspend(mmc_dev(host));
     }
 }
 EXPORT_SYMBOL(mmc_release_host);
 
 /*
  * This is a helper function, which fetches a runtime pm reference for the
  * card device and also claims the host.
  */
 void mmc_get_card(struct mmc_card *card, struct mmc_ctx *ctx)
 {
     pm_runtime_get_sync(&card->dev);
     __mmc_claim_host(card->host, ctx, NULL);
 }
 EXPORT_SYMBOL(mmc_get_card);
 
 /*
  * This is a helper function, which releases the host and drops the runtime
  * pm reference for the card device.
  */
 void mmc_put_card(struct mmc_card *card, struct mmc_ctx *ctx)
 {
     struct mmc_host *host = card->host;
 
     WARN_ON(ctx && host->claimer != ctx);
 
     mmc_release_host(host);
     pm_runtime_mark_last_busy(&card->dev);
     pm_runtime_put_autosuspend(&card->dev);
 }
 EXPORT_SYMBOL(mmc_put_card);
 
 /*
  * Internal function that does the actual ios call to the host driver,
  * optionally printing some debug output.
  */
 static inline void mmc_set_ios(struct mmc_host *host)
 {
     struct mmc_ios *ios = &host->ios;
 
     pr_debug("%s: clock %uHz busmode %u powermode %u cs %u Vdd %u "
         "width %u timing %u\n",
          mmc_hostname(host), ios->clock, ios->bus_mode,
          ios->power_mode, ios->chip_select, ios->vdd,
          1 << ios->bus_width, ios->timing);
 
     host->ops->set_ios(host, ios);
 }
 
 /*
  * Control chip select pin on a host.
  */
 void mmc_set_chip_select(struct mmc_host *host, int mode)
 {
     host->ios.chip_select = mode;
     mmc_set_ios(host);
 }
 
 /*
  * Sets the host clock to the highest possible frequency that
  * is below "hz".
  */
 void mmc_set_clock(struct mmc_host *host, unsigned int hz)
 {
     WARN_ON(hz && hz < host->f_min);
 
     if (hz > host->f_max)
         hz = host->f_max;
 
     host->ios.clock = hz;
     mmc_set_ios(host);
 }
 
 int mmc_execute_tuning(struct mmc_card *card)
 {
     struct mmc_host *host = card->host;
     u32 opcode;
     int err;
 
     if (!host->ops->execute_tuning)
         return 0;
 
     if (host->cqe_on)
         host->cqe_ops->cqe_off(host);
 
     if (mmc_card_mmc(card))
         opcode = MMC_SEND_TUNING_BLOCK_HS200;
     else
         opcode = MMC_SEND_TUNING_BLOCK;
 
     err = host->ops->execute_tuning(host, opcode);
     if (!err) {
         mmc_retune_clear(host);
         mmc_retune_enable(host);
         return 0;
     }
 
     /* Only print error when we don't check for card removal */
     if (!host->detect_change) {
         pr_err("%s: tuning execution failed: %d\n",
             mmc_hostname(host), err);
         mmc_debugfs_err_stats_inc(host, MMC_ERR_TUNING);
     }
 
     return err;
 }
 
 /*
  * Change the bus mode (open drain/push-pull) of a host.
  */
 void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode)
 {
     host->ios.bus_mode = mode;
     mmc_set_ios(host);
 }
 
 /*
  * Change data bus width of a host.
  */
 void mmc_set_bus_width(struct mmc_host *host, unsigned int width)
 {
     host->ios.bus_width = width;
     mmc_set_ios(host);
 }
 
 /*
  * Set initial state after a power cycle or a hw_reset.
  */
 void mmc_set_initial_state(struct mmc_host *host)
 {
     if (host->cqe_on)
         host->cqe_ops->cqe_off(host);
 
     mmc_retune_disable(host);
 
     if (mmc_host_is_spi(host))
         host->ios.chip_select = MMC_CS_HIGH;
     else
         host->ios.chip_select = MMC_CS_DONTCARE;
     host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;
     host->ios.bus_width = MMC_BUS_WIDTH_1;
     host->ios.timing = MMC_TIMING_LEGACY;
     host->ios.drv_type = 0;
     host->ios.enhanced_strobe = false;
 
     /*
      * Make sure we are in non-enhanced strobe mode before we
      * actually enable it in ext_csd.
      */
     if ((host->caps2 & MMC_CAP2_HS400_ES) &&
          host->ops->hs400_enhanced_strobe)
         host->ops->hs400_enhanced_strobe(host, &host->ios);
 
     mmc_set_ios(host);
 
     mmc_crypto_set_initial_state(host);
 }
 
 /**
  * mmc_vdd_to_ocrbitnum - Convert a voltage to the OCR bit number
  * @vdd:    voltage (mV)
  * @low_bits:   prefer low bits in boundary cases
  *
  * This function returns the OCR bit number according to the provided @vdd
  * value. If conversion is not possible a negative errno value returned.
  *
  * Depending on the @low_bits flag the function prefers low or high OCR bits
  * on boundary voltages. For example,
  * with @low_bits = true, 3300 mV translates to ilog2(MMC_VDD_32_33);
  * with @low_bits = false, 3300 mV translates to ilog2(MMC_VDD_33_34);
  *
  * Any value in the [1951:1999] range translates to the ilog2(MMC_VDD_20_21).
  */
 static int mmc_vdd_to_ocrbitnum(int vdd, bool low_bits)
 {
     const int max_bit = ilog2(MMC_VDD_35_36);
     int bit;
 
     if (vdd < 1650 || vdd > 3600)
         return -EINVAL;
 
     if (vdd >= 1650 && vdd <= 1950)
         return ilog2(MMC_VDD_165_195);
 
     if (low_bits)
         vdd -= 1;
 
     /* Base 2000 mV, step 100 mV, bit's base 8. */
     bit = (vdd - 2000) / 100 + 8;
     if (bit > max_bit)
         return max_bit;
     return bit;
 }
 
 /**
  * mmc_vddrange_to_ocrmask - Convert a voltage range to the OCR mask
  * @vdd_min:    minimum voltage value (mV)
  * @vdd_max:    maximum voltage value (mV)
  *
  * This function returns the OCR mask bits according to the provided @vdd_min
  * and @vdd_max values. If conversion is not possible the function returns 0.
  *
  * Notes wrt boundary cases:
  * This function sets the OCR bits for all boundary voltages, for example
  * [3300:3400] range is translated to MMC_VDD_32_33 | MMC_VDD_33_34 |
  * MMC_VDD_34_35 mask.
  */
 u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max)
 {
     u32 mask = 0;
 
     if (vdd_max < vdd_min)
         return 0;
 
     /* Prefer high bits for the boundary vdd_max values. */
     vdd_max = mmc_vdd_to_ocrbitnum(vdd_max, false);
     if (vdd_max < 0)
         return 0;
 
     /* Prefer low bits for the boundary vdd_min values. */
     vdd_min = mmc_vdd_to_ocrbitnum(vdd_min, true);
     if (vdd_min < 0)
         return 0;
 
     /* Fill the mask, from max bit to min bit. */
     while (vdd_max >= vdd_min)
         mask |= 1 << vdd_max--;
 
     return mask;
 }
 
 static int mmc_of_get_func_num(struct device_node *node)
 {
     u32 reg;
     int ret;
 
     ret = of_property_read_u32(node, "reg", &reg);
     if (ret < 0)
         return ret;
 
     return reg;
 }
 
 struct device_node *mmc_of_find_child_device(struct mmc_host *host,
         unsigned func_num)
 {
     struct device_node *node;
 
     if (!host->parent || !host->parent->of_node)
         return NULL;
 
     for_each_child_of_node(host->parent->of_node, node) {
         if (mmc_of_get_func_num(node) == func_num)
             return node;
     }
 
     return NULL;
 }
 
 /*
  * Mask off any voltages we don't support and select
  * the lowest voltage
  */
 u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
 {
     int bit;
 
     /*
      * Sanity check the voltages that the card claims to
      * support.
      */
     if (ocr & 0x7F) {
         dev_warn(mmc_dev(host),
         "card claims to support voltages below defined range\n");
         ocr &= ~0x7F;
     }
 
     ocr &= host->ocr_avail;
     if (!ocr) {
         dev_warn(mmc_dev(host), "no support for card's volts\n");
         return 0;
     }
 
     if (host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) {
         bit = ffs(ocr) - 1;
         ocr &= 3 << bit;
         mmc_power_cycle(host, ocr);
     } else {
         bit = fls(ocr) - 1;
         ocr &= 3 << bit;
         if (bit != host->ios.vdd)
             dev_warn(mmc_dev(host), "exceeding card's volts\n");
     }
 
     return ocr;
 }
 
 int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage)
 {
     int err = 0;
     int old_signal_voltage = host->ios.signal_voltage;
 
     host->ios.signal_voltage = signal_voltage;
     if (host->ops->start_signal_voltage_switch)
         err = host->ops->start_signal_voltage_switch(host, &host->ios);
 
     if (err)
         host->ios.signal_voltage = old_signal_voltage;
 
     return err;
 
 }
 
 void mmc_set_initial_signal_voltage(struct mmc_host *host)
 {
     /* Try to set signal voltage to 3.3V but fall back to 1.8v or 1.2v */
     if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330))
         dev_dbg(mmc_dev(host), "Initial signal voltage of 3.3v\n");
     else if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180))
         dev_dbg(mmc_dev(host), "Initial signal voltage of 1.8v\n");
     else if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120))
         dev_dbg(mmc_dev(host), "Initial signal voltage of 1.2v\n");
 }
 
 int mmc_host_set_uhs_voltage(struct mmc_host *host)
 {
     u32 clock;
 
     /*
      * During a signal voltage level switch, the clock must be gated
      * for 5 ms according to the SD spec
      */
     clock = host->ios.clock;
     host->ios.clock = 0;
     mmc_set_ios(host);
 
     if (mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180))
         return -EAGAIN;
 
     /* Keep clock gated for at least 10 ms, though spec only says 5 ms */
     mmc_delay(10);
     host->ios.clock = clock;
     mmc_set_ios(host);
 
     return 0;
 }
 
 int mmc_set_uhs_voltage(struct mmc_host *host, u32 ocr)
 {
     struct mmc_command cmd = {};
     int err = 0;
 
     /*
      * If we cannot switch voltages, return failure so the caller
      * can continue without UHS mode
      */
     if (!host->ops->start_signal_voltage_switch)
         return -EPERM;
     if (!host->ops->card_busy)
         pr_warn("%s: cannot verify signal voltage switch\n",
             mmc_hostname(host));
 
     cmd.opcode = SD_SWITCH_VOLTAGE;
     cmd.arg = 0;
     cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 
     err = mmc_wait_for_cmd(host, &cmd, 0);
     if (err)
         goto power_cycle;
 
     if (!mmc_host_is_spi(host) && (cmd.resp[0] & R1_ERROR))
         return -EIO;
 
     /*
      * The card should drive cmd and dat[0:3] low immediately
      * after the response of cmd11, but wait 1 ms to be sure
      */
     mmc_delay(1);
     if (host->ops->card_busy && !host->ops->card_busy(host)) {
         err = -EAGAIN;
         goto power_cycle;
     }
 
     if (mmc_host_set_uhs_voltage(host)) {
         /*
          * Voltages may not have been switched, but we've already
          * sent CMD11, so a power cycle is required anyway
          */
         err = -EAGAIN;
         goto power_cycle;
     }
 
     /* Wait for at least 1 ms according to spec */
     mmc_delay(1);
 
     /*
      * Failure to switch is indicated by the card holding
      * dat[0:3] low
      */
     if (host->ops->card_busy && host->ops->card_busy(host))
         err = -EAGAIN;
 
 power_cycle:
     if (err) {
         pr_debug("%s: Signal voltage switch failed, "
             "power cycling card\n", mmc_hostname(host));
         mmc_power_cycle(host, ocr);
     }
 
     return err;
 }
 
 /*
  * Select timing parameters for host.
  */
 void mmc_set_timing(struct mmc_host *host, unsigned int timing)
 {
     host->ios.timing = timing;
     mmc_set_ios(host);
 }
 
 /*
  * Select appropriate driver type for host.
  */
 void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type)
 {
     host->ios.drv_type = drv_type;
     mmc_set_ios(host);
 }
 
 int mmc_select_drive_strength(struct mmc_card *card, unsigned int max_dtr,
                   int card_drv_type, int *drv_type)
 {
     struct mmc_host *host = card->host;
     int host_drv_type = SD_DRIVER_TYPE_B;
 
     *drv_type = 0;
 
     if (!host->ops->select_drive_strength)
         return 0;
 
     /* Use SD definition of driver strength for hosts */
     if (host->caps & MMC_CAP_DRIVER_TYPE_A)
         host_drv_type |= SD_DRIVER_TYPE_A;
 
     if (host->caps & MMC_CAP_DRIVER_TYPE_C)
         host_drv_type |= SD_DRIVER_TYPE_C;
 
     if (host->caps & MMC_CAP_DRIVER_TYPE_D)
         host_drv_type |= SD_DRIVER_TYPE_D;
 
     /*
      * The drive strength that the hardware can support
      * depends on the board design.  Pass the appropriate
      * information and let the hardware specific code
      * return what is possible given the options
      */
     return host->ops->select_drive_strength(card, max_dtr,
                         host_drv_type,
                         card_drv_type,
                         drv_type);
 }
 
 /*
  * Apply power to the MMC stack.  This is a two-stage process.
  * First, we enable power to the card without the clock running.
  * We then wait a bit for the power to stabilise.  Finally,
  * enable the bus drivers and clock to the card.
  *
  * We must _NOT_ enable the clock prior to power stablising.
  *
  * If a host does all the power sequencing itself, ignore the
  * initial MMC_POWER_UP stage.
  */
 void mmc_power_up(struct mmc_host *host, u32 ocr)
 {
     if (host->ios.power_mode == MMC_POWER_ON)
         return;
 
     mmc_pwrseq_pre_power_on(host);
 
     host->ios.vdd = fls(ocr) - 1;
     host->ios.power_mode = MMC_POWER_UP;
     /* Set initial state and call mmc_set_ios */
     mmc_set_initial_state(host);
 
     mmc_set_initial_signal_voltage(host);
 
     /*
      * This delay should be sufficient to allow the power supply
      * to reach the minimum voltage.
      */
     mmc_delay(host->ios.power_delay_ms);
 
     mmc_pwrseq_post_power_on(host);
 
     host->ios.clock = host->f_init;
 
     host->ios.power_mode = MMC_POWER_ON;
     mmc_set_ios(host);
 
     /*
      * This delay must be at least 74 clock sizes, or 1 ms, or the
      * time required to reach a stable voltage.
      */
     mmc_delay(host->ios.power_delay_ms);
 }
 
 void mmc_power_off(struct mmc_host *host)
 {
     if (host->ios.power_mode == MMC_POWER_OFF)
         return;
 
     mmc_pwrseq_power_off(host);
 
     host->ios.clock = 0;
     host->ios.vdd = 0;
 
     host->ios.power_mode = MMC_POWER_OFF;
     /* Set initial state and call mmc_set_ios */
     mmc_set_initial_state(host);
 
     /*
      * Some configurations, such as the 802.11 SDIO card in the OLPC
      * XO-1.5, require a short delay after poweroff before the card
      * can be successfully turned on again.
      */
     mmc_delay(1);
 }
 
 void mmc_power_cycle(struct mmc_host *host, u32 ocr)
 {
     mmc_power_off(host);
     /* Wait at least 1 ms according to SD spec */
     mmc_delay(1);
     mmc_power_up(host, ocr);
 }
 
 /*
  * Assign a mmc bus handler to a host. Only one bus handler may control a
  * host at any given time.
  */
 void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops)
 {
     host->bus_ops = ops;
 }
 
 /*
  * Remove the current bus handler from a host.
  */
 void mmc_detach_bus(struct mmc_host *host)
 {
     host->bus_ops = NULL;
 }
 
 void _mmc_detect_change(struct mmc_host *host, unsigned long delay, bool cd_irq)
 {
     /*
      * Prevent system sleep for 5s to allow user space to consume the
      * corresponding uevent. This is especially useful, when CD irq is used
      * as a system wakeup, but doesn't hurt in other cases.
      */
     if (cd_irq && !(host->caps & MMC_CAP_NEEDS_POLL))
         __pm_wakeup_event(host->ws, 5000);
 
     host->detect_change = 1;
     mmc_schedule_delayed_work(&host->detect, delay);
 }
 
 /**
  *  mmc_detect_change - process change of state on a MMC socket
  *  @host: host which changed state.
  *  @delay: optional delay to wait before detection (jiffies)
  *
  *  MMC drivers should call this when they detect a card has been
  *  inserted or removed. The MMC layer will confirm that any
  *  present card is still functional, and initialize any newly
  *  inserted.
  */
 void mmc_detect_change(struct mmc_host *host, unsigned long delay)
 {
     _mmc_detect_change(host, delay, true);
 }
 EXPORT_SYMBOL(mmc_detect_change);
 
 void mmc_init_erase(struct mmc_card *card)
 {
     unsigned int sz;
 
     if (is_power_of_2(card->erase_size))
         card->erase_shift = ffs(card->erase_size) - 1;
     else
         card->erase_shift = 0;
 
     /*
      * It is possible to erase an arbitrarily large area of an SD or MMC
      * card.  That is not desirable because it can take a long time
      * (minutes) potentially delaying more important I/O, and also the
      * timeout calculations become increasingly hugely over-estimated.
      * Consequently, 'pref_erase' is defined as a guide to limit erases
      * to that size and alignment.
      *
      * For SD cards that define Allocation Unit size, limit erases to one
      * Allocation Unit at a time.
      * For MMC, have a stab at ai good value and for modern cards it will
      * end up being 4MiB. Note that if the value is too small, it can end
      * up taking longer to erase. Also note, erase_size is already set to
      * High Capacity Erase Size if available when this function is called.
      */
     if (mmc_card_sd(card) && card->ssr.au) {
         card->pref_erase = card->ssr.au;
         card->erase_shift = ffs(card->ssr.au) - 1;
     } else if (card->erase_size) {
         sz = (card->csd.capacity << (card->csd.read_blkbits - 9)) >> 11;
         if (sz < 128)
             card->pref_erase = 512 * 1024 / 512;
         else if (sz < 512)
             card->pref_erase = 1024 * 1024 / 512;
         else if (sz < 1024)
             card->pref_erase = 2 * 1024 * 1024 / 512;
         else
             card->pref_erase = 4 * 1024 * 1024 / 512;
         if (card->pref_erase < card->erase_size)
             card->pref_erase = card->erase_size;
         else {
             sz = card->pref_erase % card->erase_size;
             if (sz)
                 card->pref_erase += card->erase_size - sz;
         }
     } else
         card->pref_erase = 0;
 }
 
 static unsigned int mmc_mmc_erase_timeout(struct mmc_card *card,
                           unsigned int arg, unsigned int qty)
 {
     unsigned int erase_timeout;
 
     if (arg == MMC_DISCARD_ARG ||
         (arg == MMC_TRIM_ARG && card->ext_csd.rev >= 6)) {
         erase_timeout = card->ext_csd.trim_timeout;
     } else if (card->ext_csd.erase_group_def & 1) {
         /* High Capacity Erase Group Size uses HC timeouts */
         if (arg == MMC_TRIM_ARG)
             erase_timeout = card->ext_csd.trim_timeout;
         else
             erase_timeout = card->ext_csd.hc_erase_timeout;
     } else {
         /* CSD Erase Group Size uses write timeout */
         unsigned int mult = (10 << card->csd.r2w_factor);
         unsigned int timeout_clks = card->csd.taac_clks * mult;
         unsigned int timeout_us;
 
         /* Avoid overflow: e.g. taac_ns=80000000 mult=1280 */
         if (card->csd.taac_ns < 1000000)
             timeout_us = (card->csd.taac_ns * mult) / 1000;
         else
             timeout_us = (card->csd.taac_ns / 1000) * mult;
 
         /*
          * ios.clock is only a target.  The real clock rate might be
          * less but not that much less, so fudge it by multiplying by 2.
          */
         timeout_clks <<= 1;
         timeout_us += (timeout_clks * 1000) /
                   (card->host->ios.clock / 1000);
 
         erase_timeout = timeout_us / 1000;
 
         /*
          * Theoretically, the calculation could underflow so round up
          * to 1ms in that case.
          */
         if (!erase_timeout)
             erase_timeout = 1;
     }
 
     /* Multiplier for secure operations */
     if (arg & MMC_SECURE_ARGS) {
         if (arg == MMC_SECURE_ERASE_ARG)
             erase_timeout *= card->ext_csd.sec_erase_mult;
         else
             erase_timeout *= card->ext_csd.sec_trim_mult;
     }
 
     erase_timeout *= qty;
 
     /*
      * Ensure at least a 1 second timeout for SPI as per
      * 'mmc_set_data_timeout()'
      */
     if (mmc_host_is_spi(card->host) && erase_timeout < 1000)
         erase_timeout = 1000;
 
     return erase_timeout;
 }
 
 static unsigned int mmc_sd_erase_timeout(struct mmc_card *card,
                      unsigned int arg,
                      unsigned int qty)
 {
     unsigned int erase_timeout;
 
     /* for DISCARD none of the below calculation applies.
      * the busy timeout is 250msec per discard command.
      */
     if (arg == SD_DISCARD_ARG)
         return SD_DISCARD_TIMEOUT_MS;
 
     if (card->ssr.erase_timeout) {
         /* Erase timeout specified in SD Status Register (SSR) */
         erase_timeout = card->ssr.erase_timeout * qty +
                 card->ssr.erase_offset;
     } else {
         /*
          * Erase timeout not specified in SD Status Register (SSR) so
          * use 250ms per write block.
          */
         erase_timeout = 250 * qty;
     }
 
     /* Must not be less than 1 second */
     if (erase_timeout < 1000)
         erase_timeout = 1000;
 
     return erase_timeout;
 }
 
 static unsigned int mmc_erase_timeout(struct mmc_card *card,
                       unsigned int arg,
                       unsigned int qty)
 {
     if (mmc_card_sd(card))
         return mmc_sd_erase_timeout(card, arg, qty);
     else
         return mmc_mmc_erase_timeout(card, arg, qty);
 }
 
 static int mmc_do_erase(struct mmc_card *card, unsigned int from,
             unsigned int to, unsigned int arg)
 {
     struct mmc_command cmd = {};
     unsigned int qty = 0, busy_timeout = 0;
     bool use_r1b_resp;
     int err;
 
     mmc_retune_hold(card->host);
 
     /*
      * qty is used to calculate the erase timeout which depends on how many
      * erase groups (or allocation units in SD terminology) are affected.
      * We count erasing part of an erase group as one erase group.
      * For SD, the allocation units are always a power of 2.  For MMC, the
      * erase group size is almost certainly also power of 2, but it does not
      * seem to insist on that in the JEDEC standard, so we fall back to
      * division in that case.  SD may not specify an allocation unit size,
      * in which case the timeout is based on the number of write blocks.
      *
      * Note that the timeout for secure trim 2 will only be correct if the
      * number of erase groups specified is the same as the total of all
      * preceding secure trim 1 commands.  Since the power may have been
      * lost since the secure trim 1 commands occurred, it is generally
      * impossible to calculate the secure trim 2 timeout correctly.
      */
     if (card->erase_shift)
         qty += ((to >> card->erase_shift) -
             (from >> card->erase_shift)) + 1;
     else if (mmc_card_sd(card))
         qty += to - from + 1;
     else
         qty += ((to / card->erase_size) -
             (from / card->erase_size)) + 1;
 
     if (!mmc_card_blockaddr(card)) {
         from <<= 9;
         to <<= 9;
     }
 
     if (mmc_card_sd(card))
         cmd.opcode = SD_ERASE_WR_BLK_START;
     else
         cmd.opcode = MMC_ERASE_GROUP_START;
     cmd.arg = from;
     cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
     err = mmc_wait_for_cmd(card->host, &cmd, 0);
     if (err) {
         pr_err("mmc_erase: group start error %d, "
                "status %#x\n", err, cmd.resp[0]);
         err = -EIO;
         goto out;
     }
 
     memset(&cmd, 0, sizeof(struct mmc_command));
     if (mmc_card_sd(card))
         cmd.opcode = SD_ERASE_WR_BLK_END;
     else
         cmd.opcode = MMC_ERASE_GROUP_END;
     cmd.arg = to;
     cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
     err = mmc_wait_for_cmd(card->host, &cmd, 0);
     if (err) {
         pr_err("mmc_erase: group end error %d, status %#x\n",
                err, cmd.resp[0]);
         err = -EIO;
         goto out;
     }
 
     memset(&cmd, 0, sizeof(struct mmc_command));
     cmd.opcode = MMC_ERASE;
     cmd.arg = arg;
     busy_timeout = mmc_erase_timeout(card, arg, qty);
     use_r1b_resp = mmc_prepare_busy_cmd(card->host, &cmd, busy_timeout);
 
     err = mmc_wait_for_cmd(card->host, &cmd, 0);
     if (err) {
         pr_err("mmc_erase: erase error %d, status %#x\n",
                err, cmd.resp[0]);
         err = -EIO;
         goto out;
     }
 
     if (mmc_host_is_spi(card->host))
         goto out;
 
     /*
      * In case of when R1B + MMC_CAP_WAIT_WHILE_BUSY is used, the polling
      * shall be avoided.
      */
     if ((card->host->caps & MMC_CAP_WAIT_WHILE_BUSY) && use_r1b_resp)
         goto out;
 
     /* Let's poll to find out when the erase operation completes. */
     err = mmc_poll_for_busy(card, busy_timeout, false, MMC_BUSY_ERASE);
 
 out:
     mmc_retune_release(card->host);
     return err;
 }
 
 static unsigned int mmc_align_erase_size(struct mmc_card *card,
                      unsigned int *from,
                      unsigned int *to,
                      unsigned int nr)
 {
     unsigned int from_new = *from, nr_new = nr, rem;
 
     /*
      * When the 'card->erase_size' is power of 2, we can use round_up/down()
      * to align the erase size efficiently.
      */
     if (is_power_of_2(card->erase_size)) {
         unsigned int temp = from_new;
 
         from_new = round_up(temp, card->erase_size);
         rem = from_new - temp;
 
         if (nr_new > rem)
             nr_new -= rem;
         else
             return 0;
 
         nr_new = round_down(nr_new, card->erase_size);
     } else {
         rem = from_new % card->erase_size;
         if (rem) {
             rem = card->erase_size - rem;
             from_new += rem;
             if (nr_new > rem)
                 nr_new -= rem;
             else
                 return 0;
         }
 
         rem = nr_new % card->erase_size;
         if (rem)
             nr_new -= rem;
     }
 
     if (nr_new == 0)
         return 0;
 
     *to = from_new + nr_new;
     *from = from_new;
 
     return nr_new;
 }
 
 /**
  * mmc_erase - erase sectors.
  * @card: card to erase
  * @from: first sector to erase
  * @nr: number of sectors to erase
  * @arg: erase command argument
  *
  * Caller must claim host before calling this function.
  */
 int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
           unsigned int arg)
 {
     unsigned int rem, to = from + nr;
     int err;
 
     if (!(card->csd.cmdclass & CCC_ERASE))
         return -EOPNOTSUPP;
 
     if (!card->erase_size)
         return -EOPNOTSUPP;
 
     if (mmc_card_sd(card) && arg != SD_ERASE_ARG && arg != SD_DISCARD_ARG)
         return -EOPNOTSUPP;
 
     if (mmc_card_mmc(card) && (arg & MMC_SECURE_ARGS) &&
         !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN))
         return -EOPNOTSUPP;
 
     if (mmc_card_mmc(card) && (arg & MMC_TRIM_ARGS) &&
         !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN))
         return -EOPNOTSUPP;
 
     if (arg == MMC_SECURE_ERASE_ARG) {
         if (from % card->erase_size || nr % card->erase_size)
             return -EINVAL;
     }
 
     if (arg == MMC_ERASE_ARG)
         nr = mmc_align_erase_size(card, &from, &to, nr);
 
     if (nr == 0)
         return 0;
 
     if (to <= from)
         return -EINVAL;
 
     /* 'from' and 'to' are inclusive */
     to -= 1;
 
     /*
      * Special case where only one erase-group fits in the timeout budget:
      * If the region crosses an erase-group boundary on this particular
      * case, we will be trimming more than one erase-group which, does not
      * fit in the timeout budget of the controller, so we need to split it
      * and call mmc_do_erase() twice if necessary. This special case is
      * identified by the card->eg_boundary flag.
      */
     rem = card->erase_size - (from % card->erase_size);
     if ((arg & MMC_TRIM_ARGS) && (card->eg_boundary) && (nr > rem)) {
         err = mmc_do_erase(card, from, from + rem - 1, arg);
         from += rem;
         if ((err) || (to <= from))
             return err;
     }
 
     return mmc_do_erase(card, from, to, arg);
 }
 EXPORT_SYMBOL(mmc_erase);
 
 int mmc_can_erase(struct mmc_card *card)
 {
     if (card->csd.cmdclass & CCC_ERASE && card->erase_size)
         return 1;
     return 0;
 }
 EXPORT_SYMBOL(mmc_can_erase);
 
 int mmc_can_trim(struct mmc_card *card)
 {
     if ((card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN) &&
         (!(card->quirks & MMC_QUIRK_TRIM_BROKEN)))
         return 1;
     return 0;
 }
 EXPORT_SYMBOL(mmc_can_trim);
 
 int mmc_can_discard(struct mmc_card *card)
 {
     /*
      * As there's no way to detect the discard support bit at v4.5
      * use the s/w feature support filed.
      */
     if (card->ext_csd.feature_support & MMC_DISCARD_FEATURE)
         return 1;
     return 0;
 }
 EXPORT_SYMBOL(mmc_can_discard);
 
 int mmc_can_sanitize(struct mmc_card *card)
 {
     if (!mmc_can_trim(card) && !mmc_can_erase(card))
         return 0;
     if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_SANITIZE)
         return 1;
     return 0;
 }
 
 int mmc_can_secure_erase_trim(struct mmc_card *card)
 {
     if ((card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN) &&
         !(card->quirks & MMC_QUIRK_SEC_ERASE_TRIM_BROKEN))
         return 1;
     return 0;
 }
 EXPORT_SYMBOL(mmc_can_secure_erase_trim);
 
 int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from,
                 unsigned int nr)
 {
     if (!card->erase_size)
         return 0;
     if (from % card->erase_size || nr % card->erase_size)
         return 0;
     return 1;
 }
 EXPORT_SYMBOL(mmc_erase_group_aligned);
 
 static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
                         unsigned int arg)
 {
     struct mmc_host *host = card->host;
     unsigned int max_discard, x, y, qty = 0, max_qty, min_qty, timeout;
     unsigned int last_timeout = 0;
     unsigned int max_busy_timeout = host->max_busy_timeout ?
             host->max_busy_timeout : MMC_ERASE_TIMEOUT_MS;
 
     if (card->erase_shift) {
         max_qty = UINT_MAX >> card->erase_shift;
         min_qty = card->pref_erase >> card->erase_shift;
     } else if (mmc_card_sd(card)) {
         max_qty = UINT_MAX;
         min_qty = card->pref_erase;
     } else {
         max_qty = UINT_MAX / card->erase_size;
         min_qty = card->pref_erase / card->erase_size;
     }
 
     /*
      * We should not only use 'host->max_busy_timeout' as the limitation
      * when deciding the max discard sectors. We should set a balance value
      * to improve the erase speed, and it can not get too long timeout at
      * the same time.
      *
      * Here we set 'card->pref_erase' as the minimal discard sectors no
      * matter what size of 'host->max_busy_timeout', but if the
      * 'host->max_busy_timeout' is large enough for more discard sectors,
      * then we can continue to increase the max discard sectors until we
      * get a balance value. In cases when the 'host->max_busy_timeout'
      * isn't specified, use the default max erase timeout.
      */
     do {
         y = 0;
         for (x = 1; x && x <= max_qty && max_qty - x >= qty; x <<= 1) {
             timeout = mmc_erase_timeout(card, arg, qty + x);
 
             if (qty + x > min_qty && timeout > max_busy_timeout)
                 break;
 
             if (timeout < last_timeout)
                 break;
             last_timeout = timeout;
             y = x;
         }
         qty += y;
     } while (y);
 
     if (!qty)
         return 0;
 
     /*
      * When specifying a sector range to trim, chances are we might cross
      * an erase-group boundary even if the amount of sectors is less than
      * one erase-group.
      * If we can only fit one erase-group in the controller timeout budget,
      * we have to care that erase-group boundaries are not crossed by a
      * single trim operation. We flag that special case with "eg_boundary".
      * In all other cases we can just decrement qty and pretend that we
      * always touch (qty + 1) erase-groups as a simple optimization.
      */
     if (qty == 1)
         card->eg_boundary = 1;
     else
         qty--;
 
     /* Convert qty to sectors */
     if (card->erase_shift)
         max_discard = qty << card->erase_shift;
     else if (mmc_card_sd(card))
         max_discard = qty + 1;
     else
         max_discard = qty * card->erase_size;
 
     return max_discard;
 }
 
 unsigned int mmc_calc_max_discard(struct mmc_card *card)
 {
     struct mmc_host *host = card->host;
     unsigned int max_discard, max_trim;
 
     /*
      * Without erase_group_def set, MMC erase timeout depends on clock
      * frequence which can change.  In that case, the best choice is
      * just the preferred erase size.
      */
     if (mmc_card_mmc(card) && !(card->ext_csd.erase_group_def & 1))
         return card->pref_erase;
 
     max_discard = mmc_do_calc_max_discard(card, MMC_ERASE_ARG);
     if (mmc_can_trim(card)) {
         max_trim = mmc_do_calc_max_discard(card, MMC_TRIM_ARG);
         if (max_trim < max_discard || max_discard == 0)
             max_discard = max_trim;
     } else if (max_discard < card->erase_size) {
         max_discard = 0;
     }
     pr_debug("%s: calculated max. discard sectors %u for timeout %u ms\n",
         mmc_hostname(host), max_discard, host->max_busy_timeout ?
         host->max_busy_timeout : MMC_ERASE_TIMEOUT_MS);
     return max_discard;
 }
 EXPORT_SYMBOL(mmc_calc_max_discard);
 
 bool mmc_card_is_blockaddr(struct mmc_card *card)
 {
     return card ? mmc_card_blockaddr(card) : false;
 }
 EXPORT_SYMBOL(mmc_card_is_blockaddr);
 
 int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen)
 {
     struct mmc_command cmd = {};
 
     if (mmc_card_blockaddr(card) || mmc_card_ddr52(card) ||
         mmc_card_hs400(card) || mmc_card_hs400es(card))
         return 0;
 
     cmd.opcode = MMC_SET_BLOCKLEN;
     cmd.arg = blocklen;
     cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
     return mmc_wait_for_cmd(card->host, &cmd, 5);
 }
 EXPORT_SYMBOL(mmc_set_blocklen);
 
 static void mmc_hw_reset_for_init(struct mmc_host *host)
 {
     mmc_pwrseq_reset(host);
 
     if (!(host->caps & MMC_CAP_HW_RESET) || !host->ops->card_hw_reset)
         return;
     host->ops->card_hw_reset(host);
 }
 
 /**
  * mmc_hw_reset - reset the card in hardware
  * @card: card to be reset
  *
  * Hard reset the card. This function is only for upper layers, like the
  * block layer or card drivers. You cannot use it in host drivers (struct
  * mmc_card might be gone then).
  *
  * Return: 0 on success, -errno on failure
  */
 int mmc_hw_reset(struct mmc_card *card)
 {
     struct mmc_host *host = card->host;
     int ret;
 
     ret = host->bus_ops->hw_reset(host);
     if (ret < 0)
         pr_warn("%s: tried to HW reset card, got error %d\n",
             mmc_hostname(host), ret);
 
     return ret;
 }
 EXPORT_SYMBOL(mmc_hw_reset);
 
 int mmc_sw_reset(struct mmc_card *card)
 {
     struct mmc_host *host = card->host;
     int ret;
 
     if (!host->bus_ops->sw_reset)
         return -EOPNOTSUPP;
 
     ret = host->bus_ops->sw_reset(host);
     if (ret)
         pr_warn("%s: tried to SW reset card, got error %d\n",
             mmc_hostname(host), ret);
 
     return ret;
 }
 EXPORT_SYMBOL(mmc_sw_reset);
 
 static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq)
 {
     host->f_init = freq;
 
     pr_debug("%s: %s: trying to init card at %u Hz\n",
         mmc_hostname(host), __func__, host->f_init);
 
     mmc_power_up(host, host->ocr_avail);
 
     /*
      * Some eMMCs (with VCCQ always on) may not be reset after power up, so
      * do a hardware reset if possible.
      */
     mmc_hw_reset_for_init(host);
 
     /*
      * sdio_reset sends CMD52 to reset card.  Since we do not know
      * if the card is being re-initialized, just send it.  CMD52
      * should be ignored by SD/eMMC cards.
      * Skip it if we already know that we do not support SDIO commands
      */
     if (!(host->caps2 & MMC_CAP2_NO_SDIO))
         sdio_reset(host);
 
     mmc_go_idle(host);
 
     if (!(host->caps2 & MMC_CAP2_NO_SD)) {
         if (mmc_send_if_cond_pcie(host, host->ocr_avail))
             goto out;
         if (mmc_card_sd_express(host))
             return 0;
     }
 
     /* Order's important: probe SDIO, then SD, then MMC */
     if (!(host->caps2 & MMC_CAP2_NO_SDIO))
         if (!mmc_attach_sdio(host))
             return 0;
 
     if (!(host->caps2 & MMC_CAP2_NO_SD))
         if (!mmc_attach_sd(host))
             return 0;
 
     if (!(host->caps2 & MMC_CAP2_NO_MMC))
         if (!mmc_attach_mmc(host))
             return 0;
 
 out:
     mmc_power_off(host);
     return -EIO;
 }
 
 int _mmc_detect_card_removed(struct mmc_host *host)
 {
     int ret;
 
     if (!host->card || mmc_card_removed(host->card))
         return 1;
 
     ret = host->bus_ops->alive(host);
 
     /*
      * Card detect status and alive check may be out of sync if card is
      * removed slowly, when card detect switch changes while card/slot
      * pads are still contacted in hardware (refer to "SD Card Mechanical
      * Addendum, Appendix C: Card Detection Switch"). So reschedule a
      * detect work 200ms later for this case.
      */
     if (!ret && host->ops->get_cd && !host->ops->get_cd(host)) {
         mmc_detect_change(host, msecs_to_jiffies(200));
         pr_debug("%s: card removed too slowly\n", mmc_hostname(host));
     }
 
     if (ret) {
         mmc_card_set_removed(host->card);
         pr_debug("%s: card remove detected\n", mmc_hostname(host));
     }
 
     return ret;
 }
 
 int mmc_detect_card_removed(struct mmc_host *host)
 {
     struct mmc_card *card = host->card;
     int ret;
 
     WARN_ON(!host->claimed);
 
     if (!card)
         return 1;
 
     if (!mmc_card_is_removable(host))
         return 0;
 
     ret = mmc_card_removed(card);
     /*
      * The card will be considered unchanged unless we have been asked to
      * detect a change or host requires polling to provide card detection.
      */
     if (!host->detect_change && !(host->caps & MMC_CAP_NEEDS_POLL))
         return ret;
 
     host->detect_change = 0;
     if (!ret) {
         ret = _mmc_detect_card_removed(host);
         if (ret && (host->caps & MMC_CAP_NEEDS_POLL)) {
             /*
              * Schedule a detect work as soon as possible to let a
              * rescan handle the card removal.
              */
             cancel_delayed_work(&host->detect);
             _mmc_detect_change(host, 0, false);
         }
     }
 
     return ret;
 }
 EXPORT_SYMBOL(mmc_detect_card_removed);
 
 int mmc_card_alternative_gpt_sector(struct mmc_card *card, sector_t *gpt_sector)
 {
     unsigned int boot_sectors_num;
 
     if ((!(card->host->caps2 & MMC_CAP2_ALT_GPT_TEGRA)))
         return -EOPNOTSUPP;
 
     /* filter out unrelated cards */
     if (card->ext_csd.rev < 3 ||
         !mmc_card_mmc(card) ||
         !mmc_card_is_blockaddr(card) ||
          mmc_card_is_removable(card->host))
         return -ENOENT;
 
     /*
      * eMMC storage has two special boot partitions in addition to the
      * main one.  NVIDIA's bootloader linearizes eMMC boot0->boot1->main
      * accesses, this means that the partition table addresses are shifted
      * by the size of boot partitions.  In accordance with the eMMC
      * specification, the boot partition size is calculated as follows:
      *
      *  boot partition size = 128K byte x BOOT_SIZE_MULT
      *
      * Calculate number of sectors occupied by the both boot partitions.
      */
     boot_sectors_num = card->ext_csd.raw_boot_mult * SZ_128K /
                SZ_512 * MMC_NUM_BOOT_PARTITION;
 
     /* Defined by NVIDIA and used by Android devices. */
     *gpt_sector = card->ext_csd.sectors - boot_sectors_num - 1;
 
     return 0;
 }
 EXPORT_SYMBOL(mmc_card_alternative_gpt_sector);
 
 void mmc_rescan(struct work_struct *work)
 {
     struct mmc_host *host =
         container_of(work, struct mmc_host, detect.work);
     int i;
 
     if (host->rescan_disable)
         return;
 
     /* If there is a non-removable card registered, only scan once */
     if (!mmc_card_is_removable(host) && host->rescan_entered)
         return;
     host->rescan_entered = 1;
 
     if (host->trigger_card_event && host->ops->card_event) {
         mmc_claim_host(host);
         host->ops->card_event(host);
         mmc_release_host(host);
         host->trigger_card_event = false;
     }
 
     /* Verify a registered card to be functional, else remove it. */
     if (host->bus_ops)
         host->bus_ops->detect(host);
 
     host->detect_change = 0;
 
     /* if there still is a card present, stop here */
     if (host->bus_ops != NULL)
         goto out;
 
     mmc_claim_host(host);
     if (mmc_card_is_removable(host) && host->ops->get_cd &&
             host->ops->get_cd(host) == 0) {
         mmc_power_off(host);
         mmc_release_host(host);
         goto out;
     }
 
     /* If an SD express card is present, then leave it as is. */
     if (mmc_card_sd_express(host)) {
         mmc_release_host(host);
         goto out;
     }
 
     for (i = 0; i < ARRAY_SIZE(freqs); i++) {
         unsigned int freq = freqs[i];
         if (freq > host->f_max) {
             if (i + 1 < ARRAY_SIZE(freqs))
                 continue;
             freq = host->f_max;
         }
         if (!mmc_rescan_try_freq(host, max(freq, host->f_min)))
             break;
         if (freqs[i] <= host->f_min)
             break;
     }
 
     /*
      * Ignore the command timeout errors observed during
      * the card init as those are excepted.
      */
     host->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;
     mmc_release_host(host);
 
  out:
     if (host->caps & MMC_CAP_NEEDS_POLL)
         mmc_schedule_delayed_work(&host->detect, HZ);
 }
 
 void mmc_start_host(struct mmc_host *host)
 {
     host->f_init = max(min(freqs[0], host->f_max), host->f_min);
     host->rescan_disable = 0;
 
     if (!(host->caps2 & MMC_CAP2_NO_PRESCAN_POWERUP)) {
         mmc_claim_host(host);
         mmc_power_up(host, host->ocr_avail);
         mmc_release_host(host);
     }
 
     mmc_gpiod_request_cd_irq(host);
     _mmc_detect_change(host, 0, false);
 }
 
 void __mmc_stop_host(struct mmc_host *host)
 {
     if (host->slot.cd_irq >= 0) {
         mmc_gpio_set_cd_wake(host, false);
         disable_irq(host->slot.cd_irq);
     }
 
     host->rescan_disable = 1;
     cancel_delayed_work_sync(&host->detect);
 }
 
 void mmc_stop_host(struct mmc_host *host)
 {
     __mmc_stop_host(host);
 
     /* clear pm flags now and let card drivers set them as needed */
     host->pm_flags = 0;
 
     if (host->bus_ops) {
         /* Calling bus_ops->remove() with a claimed host can deadlock */
         host->bus_ops->remove(host);
         mmc_claim_host(host);
         mmc_detach_bus(host);
         mmc_power_off(host);
         mmc_release_host(host);
         return;
     }
 
     mmc_claim_host(host);
     mmc_power_off(host);
     mmc_release_host(host);
 }
 
 static int __init mmc_init(void)
 {
     int ret;
 
     ret = mmc_register_bus();
     if (ret)
         return ret;
 
     ret = mmc_register_host_class();
     if (ret)
         goto unregister_bus;
 
     ret = sdio_register_bus();
     if (ret)
         goto unregister_host_class;
 
     return 0;
 
 unregister_host_class:
     mmc_unregister_host_class();
 unregister_bus:
     mmc_unregister_bus();
     return ret;
 }
 
 static void __exit mmc_exit(void)
 {
     sdio_unregister_bus();
     mmc_unregister_host_class();
     mmc_unregister_bus();
 }
 
 subsys_initcall(mmc_init);
 module_exit(mmc_exit);
 
 MODULE_LICENSE("GPL");

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