> -----Original Message-----
> From: linux-mmc-ow...@vger.kernel.org
> [mailto:linux-mmc-ow...@vger.kernel.org] On Behalf Of Jaehoon Chung
> Sent: Thursday, October 27, 2011 7:10 PM
> To: linux-mmc
> Cc: Chris Ball; Kyungmin Park; Hanumath Prasad
> Subject: [PATCH] mmc: support BKOPS feature for eMMC
>
> Background operation(BKOPS) is one of eMMC's features.
>
> If set the URGENT_BKOPS in response, we can notify that card nedd the BKOPS.
> And all I/O request is done, then run background operation.
> If request read/write operation during BKOPS, issue HPI interrupt.
>
> If you want to use this feature, should be set MMC_CAP2_BKOPS.
>
> Signed-off-by: Jaehoon Chung <jh80.ch...@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.p...@samsung.com>
> CC: Hanumath Prasad <hanumath.pra...@stericsson.com>
> ---
> drivers/mmc/card/block.c | 13 +++++++-
> drivers/mmc/card/queue.c | 1 +
> drivers/mmc/core/core.c | 77
> ++++++++++++++++++++++++++++++++++++++++++++
> drivers/mmc/core/mmc.c | 21 ++++++++++++
> drivers/mmc/core/mmc_ops.c | 4 ++
> include/linux/mmc/card.h | 11 ++++++
> include/linux/mmc/core.h | 2 +
> include/linux/mmc/host.h | 1 +
> include/linux/mmc/mmc.h | 4 ++
> 9 files changed, 133 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 4fd5723..edbed7a 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -1185,14 +1185,25 @@ 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);
>
> + if (mmc_card_doing_bkops(card)) {
> + if (mmc_interrupt_bkops(card))
> + goto cmd_abort;
> + }
> +
> switch (status) {
> case MMC_BLK_SUCCESS:
> case MMC_BLK_PARTIAL:
> + spin_lock_irq(&md->lock);
> + /*
> + * Check BKOPS urgency from each R1 response
> + */
> + if (mmc_card_mmc(card) &&
> + (brq->cmd.resp[0] & R1_URGENT_BKOPS))
> + mmc_card_set_need_bkops(card);
> /*
> * A block was successfully transferred.
> */
> mmc_blk_reset_success(md, type);
> - spin_lock_irq(&md->lock);
> ret = __blk_end_request(req, 0,
> brq->data.bytes_xfered);
> spin_unlock_irq(&md->lock);
> diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
> index dcad59c..31e5eca 100644
> --- a/drivers/mmc/card/queue.c
> +++ b/drivers/mmc/card/queue.c
> @@ -68,6 +68,7 @@ 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);
Maybe put mmc_interrupt_bkops(card) here is better, I think.
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 5278ffb..7ef270d 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;
> +
> + if ((!card || !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("error %d starting bkops\n", err);
> + mmc_card_clr_need_bkops(card);
> + goto out;
> + }
> + spin_lock_irqsave(&card->host->lock, flags);
> + mmc_card_clr_need_bkops(card);
> + 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);
> @@ -466,6 +510,39 @@ 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;
> + unsigned long flags;
> + u32 status;
> +
> + BUG_ON(!card);
> +
> + /* send HPI to interrupt BKOPS. */
> + err = mmc_send_hpi_cmd(card, &status);
What will be happened if eMMC card only support BKOPS but not support HPI?
> + if (err || R1_CURRENT_STATE(status) == 7) {
> + do {
> + err = mmc_send_status(card, &status);
> + if (err)
> + return err;
> + } while (R1_CURRENT_STATE(status) == 7);
> + }
> + spin_lock_irqsave(&card->host->lock, flags);
> + mmc_card_clr_doing_bkops(card);
> + spin_unlock_irqrestore(&card->host->lock, flags);
> + return 0;
> +}
> +EXPORT_SYMBOL(mmc_interrupt_bkops);
> +
> +/**
> * 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 3627044..b16db45 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -448,6 +448,10 @@ 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;
> +
> /* check whether the eMMC card supports HPI */
> if (ext_csd[EXT_CSD_HPI_FEATURES] & 0x1) {
> card->ext_csd.hpi = 1;
> @@ -909,6 +913,23 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
> }
>
> /*
> + * enable BKOPS feature (if supported)
> + */
> + if (card->ext_csd.bkops) {
> + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> + EXT_CSD_BKOPS_EN, 1, 0);
> + if (err && err != -EBADMSG)
> + goto free_card;
> +
> + if (err) {
> + pr_warning("%s: Enabling BKOPS failed\n",
> + mmc_hostname(card->host));
> + err = 0;
> + } else
> + card->ext_csd.bkops_en = 1;
> + }
Just found this bit is one time programmable, so that is to say this bit is not
suitable for driver to change.
> +
> + /*
> * Enable HPI feature (if supported)
> */
> if (card->ext_csd.hpi) {
> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
> index 007863e..7653e33 100644
> --- a/drivers/mmc/core/mmc_ops.c
> +++ b/drivers/mmc/core/mmc_ops.c
> @@ -398,6 +398,10 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index,
> u8 value,
> 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 6e04e10..f4abb7c 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -71,6 +71,8 @@ struct mmc_ext_csd {
> bool hpi_en; /* HPI enablebit */
> bool hpi; /* HPI support bit */
> unsigned int hpi_cmd; /* cmd used as HPI */
> + bool bkops; /* background support bit */
> + bool bkops_en; /* background enable bit */
> u8 raw_partition_support; /* 160 */
> u8 raw_erased_mem_count; /* 181 */
> u8 raw_ext_csd_structure; /* 194 */
> @@ -206,6 +208,8 @@ struct mmc_card {
> #define MMC_STATE_HIGHSPEED_DDR (1<<4) /* card is in high
> speed mode
> */
> #define MMC_STATE_ULTRAHIGHSPEED (1<<5) /* card is in ultra
> high speed
> mode */
> #define MMC_CARD_SDXC (1<<6) /* card is SDXC */
> +#define MMC_STATE_NEED_BKOPS (1<<7) /* card need to do BKOPS */
> +#define MMC_STATE_DOING_BKOPS (1<<8) /* 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
> */
> @@ -365,6 +369,8 @@ static inline void __maybe_unused remove_quirk(struct
> mmc_card *card, int data)
> #define mmc_card_ddr_mode(c) ((c)->state & MMC_STATE_HIGHSPEED_DDR)
> #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_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)
> @@ -373,6 +379,11 @@ static inline void __maybe_unused remove_quirk(struct
> mmc_card *card, int data)
> #define mmc_card_set_ddr_mode(c) ((c)->state |=
> MMC_STATE_HIGHSPEED_DDR)
> #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_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 174a844..600a177 100644
> --- a/include/linux/mmc/core.h
> +++ b/include/linux/mmc/core.h
> @@ -134,6 +134,7 @@ struct mmc_host;
> struct mmc_card;
> struct mmc_async_req;
>
> +extern int mmc_interrupt_bkops(struct mmc_card *);
> 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 +164,7 @@ 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 a3ac9c4..692e5f6 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -242,6 +242,7 @@ struct mmc_host {
> #define MMC_CAP2_CACHE_CTRL (1 << 1) /* Allow cache control */
> #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_BKOPS (1 << 4) /* 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 0e71356..283b848 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_URGENT_BKOPS (1 << 6) /* sx, a */
> #define R1_APP_CMD (1 << 5) /* sr, c */
>
> #define R1_STATE_IDLE 0
> @@ -278,6 +279,8 @@ struct _mmc_csd {
> #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_ERASE_GROUP_DEF 175 /* R/W */
> @@ -313,6 +316,7 @@ struct _mmc_csd {
> #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 */
>
> /*
> --
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