On Thu, Jan 5, 2012 at 6:25 AM, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote:
>
> Enable eMMC background operations (BKOPS) feature.
>
> If URGENT_BKOPS is set after a response, note that BKOPS
> are required. After all I/O requests are finished, run
> BKOPS if required. Should read/write operations be requested
> during BKOPS, first issue HPI to interrupt the ongoing BKOPS
> and then service the request.
>
> If you want to enable this feature, set MMC_CAP2_BKOPS.
>
> Future considerations
> * Check BKOPS_LEVEL=1 and start BKOPS in a preventive manner.
> * Interrupt ongoing BKOPS before powering off the card.
> * How get BKOPS_STATUS value.(periodically send ext_csd command?)
>
> Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---
> Changelog V5:
> - Rebase based on the latest mmc-next.
> - modify codes based-on Chris's comment
> Changelog V4:
> - Add mmc_read_bkops_status
> - When URGENT_BKOPS(level2-3), didn't use HPI command.
> - In mmc_switch(), use R1B/R1 according to level.
> Changelog V3:
> - move the bkops setting's location in mmc_blk_issue_rw_rq
> - modify condition checking
> - bkops_en is assigned ext_csd[EXT_CSD_BKOPS_EN] instead of "1"
> - remove the unused code
> - change pr_debug instead of pr_warn in mmc_send_hpi_cmd
> - Add the Future consideration suggested by Per
> Changelog V2:
> - Use EXCEPTION_STATUS instead of URGENT_BKOPS
> - Add function to check Exception_status(for eMMC4.5)
>
> drivers/mmc/card/block.c | 11 +++++
> drivers/mmc/card/queue.c | 3 +
> drivers/mmc/core/core.c | 105 ++++++++++++++++++++++++++++++++++++++++++++
> drivers/mmc/core/mmc.c | 8 +++
> drivers/mmc/core/mmc_ops.c | 12 +++++-
> include/linux/mmc/card.h | 13 +++++
> include/linux/mmc/core.h | 4 ++
> include/linux/mmc/host.h | 1 +
> include/linux/mmc/mmc.h | 19 ++++++++
> 9 files changed, 175 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 0cad48a..5e3c580 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -1273,6 +1273,17 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
> type = rq_data_dir(req) == READ ? MMC_BLK_READ : MMC_BLK_WRITE;
> mmc_queue_bounce_post(mq_rq);
>
> + /*
> + * Check BKOPS urgency from each R1 response
> + */
> + if (mmc_card_mmc(card) &&
> + (brq->cmd.flags == MMC_RSP_R1B ||
> + brq->cmd.flags == MMC_RSP_R1) &&
I tested this patch on my setup and this condition never hit, as other
flags are also set in cmd.flags
It should have been
(brq->cmd.flags & MMC_RSP_R1B ||
brq->cmd.flags & MMC_RSP_R1)
> + (brq->cmd.resp[0] & R1_EXCEPTION_EVENT)) {
> + if (mmc_is_exception_event(card, EXT_CSD_URGENT_BKOPS))
This causes a crash on my test setup. The next req is already given to
the controller (see the mmc_start_req call a few lines above) and a
parallel request to read BKOPS_STATUS is interfering with it. This
won't work with any host controller driver which implements async_req
functions.
But there is no need to read BKOPS_STATUS at this stage anyway. By
checking R1_EXCEPTION_EVENT and the BKOPS bit inside the response, the
need to do BKOPS can be determined (as only a urgen_bkops state would
trigger a R1_EXCEPTION_EVENT in the first place)
> + mmc_card_set_need_bkops(card);
> + }
> +
> switch (status) {
> case MMC_BLK_SUCCESS:
> case MMC_BLK_PARTIAL:
> diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
> index 2517547..fd11a31 100644
> --- a/drivers/mmc/card/queue.c
> +++ b/drivers/mmc/card/queue.c
> @@ -66,6 +66,8 @@ static int mmc_queue_thread(void *d)
> spin_unlock_irq(q->queue_lock);
>
> if (req || mq->mqrq_prev->req) {
> + if (mmc_card_doing_bkops(mq->card))
> + mmc_interrupt_bkops(mq->card);
> set_current_state(TASK_RUNNING);
> mq->issue_fn(mq, req);
> } else {
> @@ -73,6 +75,7 @@ static int mmc_queue_thread(void *d)
> set_current_state(TASK_RUNNING);
> break;
> }
> + mmc_start_bkops(mq->card);
> up(&mq->thread_sem);
> schedule();
> down(&mq->thread_sem);
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 4770807..4579b24 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -238,6 +238,50 @@ 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
> + *
> + * 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)
> +{
> + int err;
> + unsigned long flags;
> +
> + BUG_ON(!card);
> + if (!card->ext_csd.bkops_en || !(card->host->caps2 & MMC_CAP2_BKOPS))
> + return;
> +
> + /*
> + * If card is already doing bkops or need for
> + * bkops flag is not set, then do nothing just
> + * return
> + */
> + if (mmc_card_doing_bkops(card) || !mmc_card_need_bkops(card))
> + return;
> +
> + mmc_claim_host(card->host);
> + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> + EXT_CSD_BKOPS_START, 1, 0);
> + if (err) {
> + pr_warning("%s: error %d starting bkops\n",
> + mmc_hostname(card->host), err);
> + mmc_card_clr_need_bkops(card);
> + goto out;
> + }
> + spin_lock_irqsave(&card->host->lock, flags);
> + mmc_card_clr_need_bkops(card);
> + if (card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2)
> + mmc_card_set_doing_bkops(card);
> + spin_unlock_irqrestore(&card->host->lock, flags);
> +out:
> + mmc_release_host(card->host);
> +}
> +EXPORT_SYMBOL(mmc_start_bkops);
> +
> static void mmc_wait_done(struct mmc_request *mrq)
> {
> complete(&mrq->completion);
> @@ -472,6 +516,67 @@ int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries
> EXPORT_SYMBOL(mmc_wait_for_cmd);
>
> /**
> + * mmc_interrupt_bkops - interrupt ongoing BKOPS
> + * @card: MMC card to check BKOPS
> + *
> + * Send HPI command to interrupt 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_interrupt_bkops(struct mmc_card *card)
> +{
> + int err = 0;
> + unsigned long flags;
> +
> + BUG_ON(!card);
> +
> + err = mmc_interrupt_hpi(card);
> +
> + spin_lock_irqsave(&card->host->lock, flags);
> + mmc_card_clr_doing_bkops(card);
> + spin_unlock_irqrestore(&card->host->lock, flags);
> +
> + return err;
> +}
> +EXPORT_SYMBOL(mmc_interrupt_bkops);
> +
> +int mmc_read_bkops_status(struct mmc_card *card)
> +{
> + int err;
> + u8 ext_csd[512];
> +
> + err = mmc_send_ext_csd(card, ext_csd);
> + if (err)
> + return err;
> +
> + card->ext_csd.raw_bkops_status = ext_csd[EXT_CSD_BKOPS_STATUS];
> + card->ext_csd.raw_exception_status = ext_csd[EXT_CSD_EXCEPTION_STATUS];
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(mmc_read_bkops_status);
> +
> +int mmc_is_exception_event(struct mmc_card *card, unsigned int value)
> +{
> + int err;
> +
> + err = mmc_read_bkops_status(card);
> + if (err) {
> + pr_err("%s: Didn't read bkops status : %d\n",
> + mmc_hostname(card->host), err);
> + return 0;
> + }
> +
> + /* In eMMC 4.41, R1_EXCEPTION_EVENT is URGENT_BKOPS */
> + if (card->ext_csd.rev == 5)
> + return 1;
> +
> + return (card->ext_csd.raw_exception_status & value) ? 1 : 0;
> +}
> +EXPORT_SYMBOL(mmc_is_exception_event);
> +
> +/**
> * 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
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 4af69d0..e132fa8 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -459,6 +459,14 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
> }
>
> if (card->ext_csd.rev >= 5) {
> + /* check whether the eMMC card support 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];
> + }
> +
> /* 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 4d41fa9..ee3bdb9 100644
> --- a/drivers/mmc/core/mmc_ops.c
> +++ b/drivers/mmc/core/mmc_ops.c
> @@ -392,13 +392,23 @@ 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 (index == EXT_CSD_BKOPS_START &&
> + card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2)
> + cmd.flags |= MMC_RSP_SPI_R1 | MMC_RSP_R1;
> + else
> + cmd.flags |= MMC_RSP_SPI_R1B | MMC_RSP_R1B;
> +
> 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 BKOPS switch*/
> + if (index == EXT_CSD_BKOPS_START)
> + return 0;
> +
> /* Must check status to be sure of no errors */
> do {
> err = mmc_send_status(card, &status);
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index 9478a6b..5c7b025 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -70,9 +70,12 @@ struct mmc_ext_csd {
> unsigned int cache_size; /* Units: KB */
> bool hpi_en; /* HPI enablebit */
> bool hpi; /* HPI support bit */
> + bool bkops; /* background support bit */
> + bool bkops_en; /* background enable bit */
> unsigned int hpi_cmd; /* cmd used as HPI */
> unsigned int boot_ro_lock; /* ro lock support */
> bool boot_ro_lockable;
> + u8 raw_exception_status; /* 53 */
> u8 raw_partition_support; /* 160 */
> u8 raw_erased_mem_count; /* 181 */
> u8 raw_ext_csd_structure; /* 194 */
> @@ -86,6 +89,7 @@ struct mmc_ext_csd {
> u8 raw_sec_erase_mult; /* 230 */
> u8 raw_sec_feature_support;/* 231 */
> u8 raw_trim_mult; /* 232 */
> + u8 raw_bkops_status; /* 246 */
> u8 raw_sectors[4]; /* 212 - 4 bytes */
>
> unsigned int feature_support;
> @@ -216,6 +220,8 @@ struct mmc_card {
> #define MMC_STATE_ULTRAHIGHSPEED (1<<5) /* card is in ultra high speed mode */
> #define MMC_CARD_SDXC (1<<6) /* card is SDXC */
> #define MMC_CARD_REMOVED (1<<7) /* card has been removed */
> +#define MMC_STATE_NEED_BKOPS (1<<8) /* card need to do BKOPS */
> +#define MMC_STATE_DOING_BKOPS (1<<9) /* card is doing BKOPS */
> unsigned int quirks; /* card quirks */
> #define MMC_QUIRK_LENIENT_FN0 (1<<0) /* allow SDIO FN0 writes outside of the VS CCCR range */
> #define MMC_QUIRK_BLKSZ_FOR_BYTE_MODE (1<<1) /* use func->cur_blksize */
> @@ -380,6 +386,8 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
> #define mmc_sd_card_uhs(c) ((c)->state & MMC_STATE_ULTRAHIGHSPEED)
> #define mmc_card_ext_capacity(c) ((c)->state & MMC_CARD_SDXC)
> #define mmc_card_removed(c) ((c) && ((c)->state & MMC_CARD_REMOVED))
> +#define mmc_card_need_bkops(c) ((c)->state & MMC_STATE_NEED_BKOPS)
> +#define mmc_card_doing_bkops(c) ((c)->state & MMC_STATE_DOING_BKOPS)
>
> #define mmc_card_set_present(c) ((c)->state |= MMC_STATE_PRESENT)
> #define mmc_card_set_readonly(c) ((c)->state |= MMC_STATE_READONLY)
> @@ -390,6 +398,11 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
> #define mmc_sd_card_set_uhs(c) ((c)->state |= MMC_STATE_ULTRAHIGHSPEED)
> #define mmc_card_set_ext_capacity(c) ((c)->state |= MMC_CARD_SDXC)
> #define mmc_card_set_removed(c) ((c)->state |= MMC_CARD_REMOVED)
> +#define mmc_card_set_need_bkops(c) ((c)->state |= MMC_STATE_NEED_BKOPS)
> +#define mmc_card_set_doing_bkops(c) ((c)->state |= MMC_STATE_DOING_BKOPS)
> +
> +#define mmc_card_clr_need_bkops(c) ((c)->state &= ~MMC_STATE_NEED_BKOPS)
> +#define mmc_card_clr_doing_bkops(c) ((c)->state &= ~MMC_STATE_DOING_BKOPS)
>
> /*
> * Quirk add/remove for MMC products.
> diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
> index 87a976c..45357c7 100644
> --- a/include/linux/mmc/core.h
> +++ b/include/linux/mmc/core.h
> @@ -134,6 +134,9 @@ struct mmc_host;
> struct mmc_card;
> struct mmc_async_req;
>
> +extern int mmc_interrupt_bkops(struct mmc_card *);
> +extern int mmc_read_bkops_status(struct mmc_card *);
> +extern int mmc_is_exception_event(struct mmc_card *, unsigned int);
> extern struct mmc_async_req *mmc_start_req(struct mmc_host *,
> struct mmc_async_req *, int *);
> extern int mmc_interrupt_hpi(struct mmc_card *);
> @@ -163,6 +166,7 @@ extern int mmc_can_sanitize(struct mmc_card *card);
> extern int mmc_can_secure_erase_trim(struct mmc_card *card);
> extern int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from,
> unsigned int nr);
> +extern void mmc_start_bkops(struct mmc_card *card);
> extern unsigned int mmc_calc_max_discard(struct mmc_card *card);
>
> extern int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen);
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 031d865..b8cb140 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -248,6 +248,7 @@ struct mmc_host {
> #define MMC_CAP2_POWEROFF_NOTIFY (1 << 2) /* Notify poweroff supported */
> #define MMC_CAP2_NO_MULTI_READ (1 << 3) /* Multiblock reads don't work */
> #define MMC_CAP2_NO_SLEEP_CMD (1 << 4) /* Don't allow sleep command */
> +#define MMC_CAP2_BKOPS (1 << 5) /* BKOPS supported */
>
> mmc_pm_flag_t pm_caps; /* supported pm features */
> unsigned int power_notify_type;
> diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
> index 665548e..8cc1a03 100644
> --- a/include/linux/mmc/mmc.h
> +++ b/include/linux/mmc/mmc.h
> @@ -138,6 +138,7 @@ static inline bool mmc_op_multi(u32 opcode)
> #define R1_CURRENT_STATE(x) ((x & 0x00001E00) >> 9) /* sx, b (4 bits) */
> #define R1_READY_FOR_DATA (1 << 8) /* sx, a */
> #define R1_SWITCH_ERROR (1 << 7) /* sx, c */
> +#define R1_EXCEPTION_EVENT (1 << 6) /* sx, a */
> #define R1_APP_CMD (1 << 5) /* sr, c */
>
> #define R1_STATE_IDLE 0
> @@ -273,11 +274,14 @@ struct _mmc_csd {
> #define EXT_CSD_FLUSH_CACHE 32 /* W */
> #define EXT_CSD_CACHE_CTRL 33 /* R/W */
> #define EXT_CSD_POWER_OFF_NOTIFICATION 34 /* R/W */
> +#define EXT_CSD_EXCEPTION_STATUS 54 /* RO */
> #define EXT_CSD_GP_SIZE_MULT 143 /* R/W */
> #define EXT_CSD_PARTITION_ATTRIBUTE 156 /* R/W */
> #define EXT_CSD_PARTITION_SUPPORT 160 /* RO */
> #define EXT_CSD_HPI_MGMT 161 /* R/W */
> #define EXT_CSD_RST_N_FUNCTION 162 /* R/W */
> +#define EXT_CSD_BKOPS_EN 163 /* R/W */
> +#define EXT_CSD_BKOPS_START 164 /* W */
> #define EXT_CSD_SANITIZE_START 165 /* W */
> #define EXT_CSD_WR_REL_PARAM 166 /* RO */
> #define EXT_CSD_BOOT_WP 173 /* R/W */
> @@ -311,9 +315,11 @@ struct _mmc_csd {
> #define EXT_CSD_PWR_CL_200_360 237 /* RO */
> #define EXT_CSD_PWR_CL_DDR_52_195 238 /* RO */
> #define EXT_CSD_PWR_CL_DDR_52_360 239 /* RO */
> +#define EXT_CSD_BKOPS_STATUS 246 /* RO */
> #define EXT_CSD_POWER_OFF_LONG_TIME 247 /* RO */
> #define EXT_CSD_GENERIC_CMD6_TIME 248 /* RO */
> #define EXT_CSD_CACHE_SIZE 249 /* RO, 4 bytes */
> +#define EXT_CSD_BKOPS_SUPPORT 502 /* RO */
> #define EXT_CSD_HPI_FEATURES 503 /* RO */
>
> /*
> @@ -379,4 +385,17 @@ struct _mmc_csd {
> #define MMC_SWITCH_MODE_CLEAR_BITS 0x02 /* Clear bits which are 1 in value */
> #define MMC_SWITCH_MODE_WRITE_BYTE 0x03 /* Set target to value */
>
> +/*
> + * BKOPS status level
> + */
> +#define EXT_CSD_BKOPS_LEVEL_2 0x2
> +
> +/*
> + * EXCEPTION_EVENT_STATUS field (eMMC4.5)
> + */
> +#define EXT_CSD_URGENT_BKOPS BIT(0)
> +#define EXT_CSD_DYNCAP_NEEDED BIT(1)
> +#define EXT_CSD_SYSPOOL_EXHAUSTED BIT(2)
> +#define EXT_CSD_PACKED_FAILURE BIT(3)
> +
> #endif /* LINUX_MMC_MMC_H */
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