Hi Sebastian.
On 10/28/2011 04:26 AM, Sebastian Rasmussen wrote:
>> 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.
>
> 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.
>
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
>> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
>> CC: Hanumath Prasad <hanumath.prasad@xxxxxxxxxxxxxx>
>> ---
>> 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);
>
> First of all, R1_URGENT_BKOPS is fine to check in cmd->resp[0], but it
> is only valid if cmd->resp contains an R1 or an R1b response. Granted,
> commands that do not have R1/R1b responses are few, but I still
> believe you need to check that with mmc_resp_type().
Ok...i will add to check for mmc_resp_type().
>
> Moreover in the eMMC 4.41 spec it was ok to check bit 6 of the status
> (which is what you do above) as that bit corresponded to URGENT_BKOPS.
> However for eMMC 4.5 this bit has been combined with other kinds of of
> exceptional situations. The bit has been renamed EXCEPTION_EVENT and
> if it is set you then need to read (using CMD8) bytes 55:54 in EXT_CSD
> named EXCEPTION_EVENTS_STATUS where bit 0 indicates URGENT_BKOPS.
Right..eMMC4.5 is modified them. So host need to check EXCEPTION_EVENTS_STATUS and
whenever need to check, host should read the ext_csd register. right?
I will modify also this point..(actually..this patch is based on eMMC4.41)
>
> So I you need to check card->ext_csd.rev here to know what method you
> need to apply to determine if BKOPS are urgent or not.
>
>> /*
>> * 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);
>> 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);
>> + 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;
>
> How about this to include/linux/mmc/mmc.h and using it here?
>
> #define EXT_CSD_BKOPS_SUPPORTED BIT(0)
>
> BTW, this is required starting from eMMC 4.5.
Consider your opinion..:)
>
>> +
>> /* 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);
>
> The BKOPS_EN property in EXT_CSD is labelled R/W which means that it
> is one time programmable. Therefore it makes no sense to write this
> every time you are initializing an eMMC. What you could do is to read
> BKOPS_EN to determine if BKOPS should, according to the eMMC, be
> enabled in the MMC framework.
Then this code is unnecessary..because card supported bkops, EXT_CSD_BKOPS_EN is set by default.
And if user want to use BKOPS,user can use IOCTL like you mentioned.
>
> According to other discussions here it seems to me as if Chris and
> others are wary of having sysfs-files enable users to write to
> one-time programmable registers. So therefore I guess the only option
> is to use the generic MMC command passthrough in mmc_blk_ioctl() to do
> such things.
>
>> + 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;
>> + }
>> +
>> + /*
>> * 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;
>
> Why is this not needed? I can see why you wouldn't want to wait until
> the card is no longer busy (as it will stay busy until BKOPS are no
> longer needed), but the bits indicating errors must surely be
> interesting to check?
I think that didn't need to check because just write any value in EXT_CSD_BKOPS_START.
>
>> +
>> /* 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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