On Tue, Jul 5, 2011 at 5:57 PM, Hanumath Prasad
<hanumath.prasad@xxxxxxxxxxxxxx> wrote:
> Background operations is an optional feature defined in eMMC4.41 spec.
> The need for BKOPS will be checked after servicing each user request
> in R1 response. If need for BKOPS flag is set, then start BKOPS when
> request queue is idle. Once bkops is started and meanwhile any
> user read/write request comes then the bkops will be interrupted by
> issuing HPI, otherwise bkops keep going until it gets finished.
> This patch is based on the four patches submitted by Chuanxiao Dong
> to linux-mmc.
>
> Signed-off-by: Hanumath Prasad <hanumath.prasad@xxxxxxxxxxxxxx>
> ---
> drivers/mmc/card/block.c | 14 +++++++-
> drivers/mmc/card/queue.c | 1 +
> drivers/mmc/core/core.c | 75 ++++++++++++++++++++++++++++++++++++++++++++
> drivers/mmc/core/mmc.c | 52 +++++++++++++++++++++++++++++-
> drivers/mmc/core/mmc_ops.c | 33 +++++++++++++++++++
> drivers/mmc/core/mmc_ops.h | 1 +
> include/linux/mmc/card.h | 14 ++++++++
> include/linux/mmc/core.h | 3 +-
> include/linux/mmc/mmc.h | 6 +++
> 9 files changed, 195 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 71da564..26a87ca 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -799,6 +799,11 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
>
> mmc_queue_bounce_pre(mq);
>
> + if (mmc_card_doing_bkops(card)) {
> + if (mmc_interrupt_bkops(card))
> + goto cmd_err;
> + }
> +
> mmc_wait_for_req(card->host, &brq.mrq);
>
> mmc_queue_bounce_post(mq);
> @@ -897,10 +902,17 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
> goto cmd_err;
> }
>
> + 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.
> */
> - spin_lock_irq(&md->lock);
> ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
> spin_unlock_irq(&md->lock);
> } while (ret);
> diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
> index c07322c..c491edd 100644
> --- a/drivers/mmc/card/queue.c
> +++ b/drivers/mmc/card/queue.c
> @@ -64,6 +64,7 @@ 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 68091dd..e5e1d7c 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -196,6 +196,48 @@ 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)
> + 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) {
> + printk(KERN_ERR "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->done_data);
> @@ -254,6 +296,39 @@ 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);
> + 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 2a7e43b..03dcbb3 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -383,9 +383,23 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
> ext_csd[EXT_CSD_TRIM_MULT];
> }
>
> - if (card->ext_csd.rev >= 5)
> + 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 support HPI */
> + if (ext_csd[EXT_CSD_HPI_FEATURES] & 0x1) {
> + card->ext_csd.hpi = 1;
> + if (ext_csd[EXT_CSD_HPI_FEATURES] & 0x2)
> + card->ext_csd.hpi_cmd =
> + MMC_STOP_TRANSMISSION;
> + else
> + card->ext_csd.hpi_cmd =
> + MMC_SEND_STATUS;
> + }
> +
> card->ext_csd.rel_param = ext_csd[EXT_CSD_WR_REL_PARAM];
> -
> + }
> if (ext_csd[EXT_CSD_ERASED_MEM_CONT])
> card->erased_byte = 0xFF;
> else
> @@ -702,6 +716,40 @@ 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) {
> + printk(KERN_WARNING "%s: Enabling BKOPS failed\n",
> + mmc_hostname(card->host));
> + err = 0;
> + } else
> + card->ext_csd.bkops_en = 1;
> + }
> +
> + /*
> + * Enable HPI feature (if supported)
> + */
> + if (card->ext_csd.hpi) {
> + err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> + EXT_CSD_HPI_MGMT, 1, 0);
> + if (err && err != -EBADMSG)
> + goto free_card;
> +
> + if (err) {
> + printk(KERN_WARNING "%s: Enabling HPI failed\n",
> + mmc_hostname(card->host));
> + err = 0;
> + } else
> + card->ext_csd.hpi_en = 1;
> + }
> +
> + /*
> * Compute bus speed.
> */
> max_dtr = (unsigned int)-1;
> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
> index 845ce7c..a4accfb 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);
> @@ -547,3 +551,32 @@ int mmc_bus_test(struct mmc_card *card, u8 bus_width)
> err = mmc_send_bus_test(card, card->host, MMC_BUS_TEST_R, width);
> return err;
> }
> +
> +int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status)
> +{
> + struct mmc_command cmd;
> + unsigned int opcode;
> + unsigned int flags;
> + int err;
> +
> + opcode = card->ext_csd.hpi_cmd;
> + if (opcode == MMC_STOP_TRANSMISSION)
> + flags = MMC_RSP_R1B | MMC_CMD_AC;
> + else if (opcode == MMC_SEND_STATUS)
> + flags = MMC_RSP_R1 | MMC_CMD_AC;
> +
> + memset(&cmd, 0, sizeof(struct mmc_command));
> + cmd.opcode = opcode;
> + cmd.arg = card->rca << 16 | 1;
> + cmd.flags = flags;
> + err = mmc_wait_for_cmd(card->host, &cmd, 0);
> + if (err) {
> + printk(KERN_ERR "error %d interrupting operation"
> + "HPI command response %#x\n",
> + err, cmd.resp[0]);
> + return err;
> + }
> + if (status)
> + *status = cmd.resp[0];
> + return 0;
> +}
> diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h
> index 9276946..d539f55 100644
> --- a/drivers/mmc/core/mmc_ops.h
> +++ b/drivers/mmc/core/mmc_ops.h
> @@ -21,6 +21,7 @@ int mmc_set_relative_addr(struct mmc_card *card);
> int mmc_send_csd(struct mmc_card *card, u32 *csd);
> int mmc_send_ext_csd(struct mmc_card *card, u8 *ext_csd);
> int mmc_send_status(struct mmc_card *card, u32 *status);
> +int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status);
> int mmc_send_cid(struct mmc_host *host, u32 *cid);
> int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp);
> int mmc_spi_set_crc(struct mmc_host *host, int use_crc);
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index c6927a4..9bbfed2 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -64,6 +64,11 @@ struct mmc_ext_csd {
> unsigned long long enhanced_area_offset; /* Units: Byte */
> unsigned int enhanced_area_size; /* Units: KB */
> unsigned int boot_size; /* in bytes */
> + bool bkops; /* background support bit */
> + bool bkops_en; /* background enable bit */
> + bool hpi_en; /*HPI enablebit */
> + bool hpi; /* HPI support bit */
> + unsigned int hpi_cmd; /* cmd used as HPI */
> };
>
> struct sd_scr {
> @@ -164,6 +169,8 @@ 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 */
> @@ -301,6 +308,8 @@ 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)
> @@ -309,6 +318,11 @@ 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 b6718e5..53dca10 100644
> --- a/include/linux/mmc/core.h
> +++ b/include/linux/mmc/core.h
> @@ -132,6 +132,7 @@ struct mmc_request {
> struct mmc_host;
> struct mmc_card;
>
> +extern int mmc_interrupt_bkops(struct mmc_card *);
> extern void mmc_wait_for_req(struct mmc_host *, struct mmc_request *);
> extern int mmc_wait_for_cmd(struct mmc_host *, struct mmc_command *, int);
> extern int mmc_app_cmd(struct mmc_host *, struct mmc_card *);
> @@ -155,7 +156,7 @@ extern int mmc_can_trim(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 int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen);
>
> extern void mmc_set_data_timeout(struct mmc_data *, const struct mmc_card *);
> diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
> index ac26a68..98aa47d 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 */
>
> /*
> @@ -262,6 +263,9 @@ struct _mmc_csd {
>
> #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_BKOPS_EN 163 /* R/W */
> +#define EXT_CSD_BKOPS_START 164 /* W */
> #define EXT_CSD_WR_REL_PARAM 166 /* RO */
> #define EXT_CSD_ERASE_GROUP_DEF 175 /* R/W */
> #define EXT_CSD_PART_CONFIG 179 /* R/W */
> @@ -283,6 +287,8 @@ struct _mmc_csd {
> #define EXT_CSD_SEC_ERASE_MULT 230 /* RO */
> #define EXT_CSD_SEC_FEATURE_SUPPORT 231 /* RO */
> #define EXT_CSD_TRIM_MULT 232 /* RO */
> +#define EXT_CSD_BKOPS_SUPPORT 502 /* RO */
> +#define EXT_CSD_HPI_FEATURES 503 /* RO */
>
> /*
> * EXT_CSD field definitions
> --
> 1.7.1
>
How does BKOPS work with card power management ? On some controllers,
regulators are switched off in between transactions after some delay.
Wouldn't the card need power to do it's BKOPS ?
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