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author | Jaehoon Chung <jh80.chung@samsung.com> | 2012-09-17 08:42:02 +0000 |
---|---|---|
committer | Chris Ball <cjb@laptop.org> | 2012-10-03 10:05:12 -0400 |
commit | 950d56acce5d401f477b91d0177605b543d63d07 (patch) | |
tree | 205505f3976d02c6ef2fa9d6c911407f0e0f6c80 /drivers/mmc | |
parent | bec9d4e5939987053169a9bb48fc58b6a2d3e237 (diff) | |
download | linux-stable-950d56acce5d401f477b91d0177605b543d63d07.tar.gz linux-stable-950d56acce5d401f477b91d0177605b543d63d07.tar.bz2 linux-stable-950d56acce5d401f477b91d0177605b543d63d07.zip |
mmc: support BKOPS feature for eMMC
Enable eMMC background operations (BKOPS) feature.
If URGENT_BKOPS is set after a response, note that BKOPS are required.
Immediately run BKOPS if required. Read/write operations should be
requested during BKOPS(LEVEL-1), then issue HPI to interrupt the
ongoing BKOPS and service the foreground operation.
(This patch only controls the LEVEL2/3.)
When repeating the writing 1GB data, at a certain time, performance is
decreased. At that time, card triggers the Level-3 or Level-2. After
running bkops, performance is recovered.
Future considerations:
* Check BKOPS_LEVEL=1 and start BKOPS in a preventive manner.
* Interrupt ongoing BKOPS before powering off the card.
* How do we get BKOPS_STATUS value (periodically send ext_csd command)?
* If using periodic bkops, also consider runtime_pm control.
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Reviewed-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r-- | drivers/mmc/core/core.c | 160 | ||||
-rw-r--r-- | drivers/mmc/core/mmc.c | 11 | ||||
-rw-r--r-- | drivers/mmc/core/mmc_ops.c | 26 |
3 files changed, 189 insertions, 8 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index af2c4d2fd69e..044cd016320e 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -26,6 +26,7 @@ #include <linux/suspend.h> #include <linux/fault-inject.h> #include <linux/random.h> +#include <linux/slab.h> #include <linux/mmc/card.h> #include <linux/mmc/host.h> @@ -41,6 +42,12 @@ #include "sd_ops.h" #include "sdio_ops.h" +/* + * Background operations can take a long time, depending on the housekeeping + * operations the card has to perform. + */ +#define MMC_BKOPS_MAX_TIMEOUT (4 * 60 * 1000) /* max time to wait in ms */ + static struct workqueue_struct *workqueue; static const unsigned freqs[] = { 400000, 300000, 200000, 100000 }; @@ -245,6 +252,70 @@ mmc_start_request(struct mmc_host *host, struct mmc_request *mrq) host->ops->request(host, mrq); } +/** + * mmc_start_bkops - start BKOPS for supported cards + * @card: MMC card to start BKOPS + * @form_exception: A flag to indicate if this function was + * called due to an exception raised by the card + * + * Start background operations whenever requested. + * When the urgent BKOPS bit is set in a R1 command response + * then background operations should be started immediately. +*/ +void mmc_start_bkops(struct mmc_card *card, bool from_exception) +{ + int err; + int timeout; + bool use_busy_signal; + + BUG_ON(!card); + + if (!card->ext_csd.bkops_en || mmc_card_doing_bkops(card)) + return; + + err = mmc_read_bkops_status(card); + if (err) { + pr_err("%s: Failed to read bkops status: %d\n", + mmc_hostname(card->host), err); + return; + } + + if (!card->ext_csd.raw_bkops_status) + return; + + if (card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2 && + from_exception) + return; + + mmc_claim_host(card->host); + if (card->ext_csd.raw_bkops_status >= EXT_CSD_BKOPS_LEVEL_2) { + timeout = MMC_BKOPS_MAX_TIMEOUT; + use_busy_signal = true; + } else { + timeout = 0; + use_busy_signal = false; + } + + err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, + EXT_CSD_BKOPS_START, 1, timeout, use_busy_signal); + if (err) { + pr_warn("%s: Error %d starting bkops\n", + mmc_hostname(card->host), err); + goto out; + } + + /* + * For urgent bkops status (LEVEL_2 and more) + * bkops executed synchronously, otherwise + * the operation is in progress + */ + if (!use_busy_signal) + mmc_card_set_doing_bkops(card); +out: + mmc_release_host(card->host); +} +EXPORT_SYMBOL(mmc_start_bkops); + static void mmc_wait_done(struct mmc_request *mrq) { complete(&mrq->completion); @@ -354,6 +425,14 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host, if (host->areq) { mmc_wait_for_req_done(host, host->areq->mrq); err = host->areq->err_check(host->card, host->areq); + /* + * Check BKOPS urgency for each R1 response + */ + if (host->card && mmc_card_mmc(host->card) && + ((mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1) || + (mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1B)) && + (host->areq->mrq->cmd->resp[0] & R1_EXCEPTION_EVENT)) + mmc_start_bkops(host->card, true); } if (!err && areq) @@ -398,7 +477,7 @@ EXPORT_SYMBOL(mmc_wait_for_req); * @card: the MMC card associated with the HPI transfer * * Issued High Priority Interrupt, and check for card status - * util out-of prg-state. + * until out-of prg-state. */ int mmc_interrupt_hpi(struct mmc_card *card) { @@ -490,6 +569,64 @@ int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries EXPORT_SYMBOL(mmc_wait_for_cmd); /** + * mmc_stop_bkops - stop ongoing BKOPS + * @card: MMC card to check BKOPS + * + * Send HPI command to stop ongoing background operations to + * allow rapid servicing of foreground operations, e.g. read/ + * writes. Wait until the card comes out of the programming state + * to avoid errors in servicing read/write requests. + */ +int mmc_stop_bkops(struct mmc_card *card) +{ + int err = 0; + + BUG_ON(!card); + err = mmc_interrupt_hpi(card); + + /* + * If err is EINVAL, we can't issue an HPI. + * It should complete the BKOPS. + */ + if (!err || (err == -EINVAL)) { + mmc_card_clr_doing_bkops(card); + err = 0; + } + + return err; +} +EXPORT_SYMBOL(mmc_stop_bkops); + +int mmc_read_bkops_status(struct mmc_card *card) +{ + int err; + u8 *ext_csd; + + /* + * In future work, we should consider storing the entire ext_csd. + */ + ext_csd = kmalloc(512, GFP_KERNEL); + if (!ext_csd) { + pr_err("%s: could not allocate buffer to receive the ext_csd.\n", + mmc_hostname(card->host)); + return -ENOMEM; + } + + mmc_claim_host(card->host); + err = mmc_send_ext_csd(card, ext_csd); + mmc_release_host(card->host); + if (err) + goto out; + + card->ext_csd.raw_bkops_status = ext_csd[EXT_CSD_BKOPS_STATUS]; + card->ext_csd.raw_exception_status = ext_csd[EXT_CSD_EXP_EVENTS_STATUS]; +out: + kfree(ext_csd); + return err; +} +EXPORT_SYMBOL(mmc_read_bkops_status); + +/** * 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 @@ -2333,9 +2470,14 @@ int mmc_suspend_host(struct mmc_host *host) mmc_bus_get(host); if (host->bus_ops && !host->bus_dead) { - - if (host->bus_ops->suspend) + if (host->bus_ops->suspend) { + if (mmc_card_doing_bkops(host->card)) { + err = mmc_stop_bkops(host->card); + if (err) + goto out; + } err = host->bus_ops->suspend(host); + } if (err == -ENOSYS || !host->bus_ops->resume) { /* @@ -2417,11 +2559,21 @@ int mmc_pm_notify(struct notifier_block *notify_block, struct mmc_host *host = container_of( notify_block, struct mmc_host, pm_notify); unsigned long flags; - + int err = 0; switch (mode) { case PM_HIBERNATION_PREPARE: case PM_SUSPEND_PREPARE: + if (host->card && mmc_card_mmc(host->card) && + mmc_card_doing_bkops(host->card)) { + err = mmc_stop_bkops(host->card); + if (err) { + pr_err("%s: didn't stop bkops\n", + mmc_hostname(host)); + return err; + } + mmc_card_clr_doing_bkops(host->card); + } spin_lock_irqsave(&host->lock, flags); host->rescan_disable = 1; diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 396b25891bb9..7509de14aa78 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -463,6 +463,17 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd) } if (card->ext_csd.rev >= 5) { + /* check whether the eMMC card supports BKOPS */ + if (ext_csd[EXT_CSD_BKOPS_SUPPORT] & 0x1) { + card->ext_csd.bkops = 1; + card->ext_csd.bkops_en = ext_csd[EXT_CSD_BKOPS_EN]; + card->ext_csd.raw_bkops_status = + ext_csd[EXT_CSD_BKOPS_STATUS]; + if (!card->ext_csd.bkops_en) + pr_info("%s: BKOPS_EN bit is not set\n", + mmc_hostname(card->host)); + } + /* check whether the eMMC card supports HPI */ if (ext_csd[EXT_CSD_HPI_FEATURES] & 0x1) { card->ext_csd.hpi = 1; diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c index 225371a28861..a0e172042e65 100644 --- a/drivers/mmc/core/mmc_ops.c +++ b/drivers/mmc/core/mmc_ops.c @@ -393,18 +393,19 @@ int mmc_spi_set_crc(struct mmc_host *host, int use_crc) } /** - * mmc_switch - modify EXT_CSD register + * __mmc_switch - modify EXT_CSD register * @card: the MMC card associated with the data transfer * @set: cmd set values * @index: EXT_CSD register index * @value: value to program into EXT_CSD register * @timeout_ms: timeout (ms) for operation performed by register write, * timeout of zero implies maximum possible timeout + * @use_busy_signal: use the busy signal as response type * * Modifies the EXT_CSD register for selected card. */ -int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, - unsigned int timeout_ms) +int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, + unsigned int timeout_ms, bool use_busy_signal) { int err; struct mmc_command cmd = {0}; @@ -418,13 +419,23 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, (index << 16) | (value << 8) | set; - cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC; + cmd.flags = MMC_CMD_AC; + if (use_busy_signal) + cmd.flags |= MMC_RSP_SPI_R1B | MMC_RSP_R1B; + else + cmd.flags |= MMC_RSP_SPI_R1 | MMC_RSP_R1; + + cmd.cmd_timeout_ms = timeout_ms; err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES); if (err) return err; + /* No need to check card status in case of unblocking command */ + if (!use_busy_signal) + return 0; + /* Must check status to be sure of no errors */ do { err = mmc_send_status(card, &status); @@ -449,6 +460,13 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, return 0; } +EXPORT_SYMBOL_GPL(__mmc_switch); + +int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, + unsigned int timeout_ms) +{ + return __mmc_switch(card, set, index, value, timeout_ms, true); +} EXPORT_SYMBOL_GPL(mmc_switch); int mmc_send_status(struct mmc_card *card, u32 *status) |