Hello Per, > On Thu, Nov 17, 2011 at 4:01 PM, Konstantin Dorfman > <kdorfman@xxxxxxxxxxxxxx> wrote: >> Hello Jaenhoon, >> >> I have a few suggestions regarding the situation when Host starts BKOPS: >> >> 1) Host should start BKOPS (based on BKOPS_STATUS or URGENT_BKOPS event) >> when going to mmc_sleep, which means that the bus is in idle state (this >> also covers the case in mmc_queue_thread, because in this case no I/O >> request exists). It seems like checking the status periodically in >> addition >> to mmc_suspend is not needed. Since if the device was in idle and we >> performed a single BKOPS then there is no point in performing another >> BKOPS >> unless there was actually another I/O request. >> >> 2) Also this implies an answer to the question about need to interrupt >> BKOPS >> before powering off card - the answer is no. > By the answer no you mean there is no risk of data corruption if > cutting power in the middle of a BKOPS. When the card is powered up > next time it will verify that bkops is in a defined state, and do > recovery if necessary. An interesting comment I got from Sebastian is > if this recovery mechanism affects card boot time. > The question is: May the card boot up slower (due to recovery) next > time if BKOPS was ongoing at power off? > I assume this recovery time should be insignificant, but I don't know for > sure. > Let me explain proposed flow: The only trigger to start BKOPS command should be mmc_power_off() function, just before sending POWER_OFF_NOTIFICATION[34] and only when BKOPS is needed (by needed I understand situation, when URGENT_BKOPS event arrived or BKOPS_STATUS 0x2 or 0x3). The flow will wait till BKOPS successfully completed and than continue to powering off the card. Power off will never occur in the middle of BKOPS. Also do not need to start BKOPS when mmc_queue_thread() is in IDLE state (no requests exists), because in such case power off should be done to card. >> 3) Based on statistical data we have (day long test) it looks like we do >> not >> need to do any preventive BKOPS caused by BKOPS_STATUS less than >> critical >> (0x3). > I proposed this "preventive action" but at that time I didn't have any > data to back it up with. I've run some day long tests and what I could > see is when BKOPS_LEVEL goes from 0 to 1, it goes back to 0 without > having to start BKOPS. Can you confirm this with your tests as well? > One explanation I got for this is that level of 1 only means the eMMC > internal cache is fragmented and not the actual memory. We have such data from card vendors, but I plan to do similar tests to confirm. I will update about the results. Thanks, Kostya > > Thanks, > Per > >> -----Original Message----- >> From: linux-mmc-owner@xxxxxxxxxxxxxxx >> [mailto:linux-mmc-owner@xxxxxxxxxxxxxxx] On Behalf Of Jaehoon Chung >> Sent: Thursday, November 17, 2011 2:50 AM >> To: linux-mmc >> Cc: Chris Ball; Kyungmin Park; Hanumath Prasad; Per Forlin; Sebastian >> Rasmussen; Dong, Chuanxiao; svenkatr@xxxxxx >> Subject: [PATCH v3] 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. 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. >> >> Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx> >> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> >> CC: Hanumath Prasad <hanumath.prasad@xxxxxxxxxxxxxx> >> --- >> 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) >> - remove unnecessary code. >> >> drivers/mmc/card/block.c | 10 +++++ >> drivers/mmc/card/queue.c | 4 ++ >> drivers/mmc/core/core.c | 87 >> ++++++++++++++++++++++++++++++++++++++++++++ >> drivers/mmc/core/mmc.c | 8 ++++ >> drivers/mmc/core/mmc_ops.c | 6 +++- >> include/linux/mmc/card.h | 12 ++++++ >> include/linux/mmc/core.h | 3 ++ >> include/linux/mmc/host.h | 1 + >> include/linux/mmc/mmc.h | 14 +++++++ >> 9 files changed, 144 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c >> index c80bb6d..9d19ebb 100644 >> --- a/drivers/mmc/card/block.c >> +++ b/drivers/mmc/card/block.c >> @@ -1188,6 +1188,16 @@ 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.resp[0] & R1_EXCEPTION_EVENT)) { >> + if (mmc_is_exception_event(card, >> + EXT_CSD_URGENT_BKOPS)) >> + 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 dcad59c..20bb4a5 100644 >> --- a/drivers/mmc/card/queue.c >> +++ b/drivers/mmc/card/queue.c >> @@ -61,6 +61,9 @@ 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 { >> @@ -68,6 +71,7 @@ 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 7ee2e07..2d2f1d5 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("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 +510,49 @@ 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_is_exception_event(struct mmc_card *card, unsigned int value) >> +{ >> + int err; >> + u8 ext_csd[512]; >> + >> + /* In eMMC 4.41, R1_EXCEPTION_EVENT is URGENT_BKOPS */ >> + if (card->ext_csd.rev == 5) >> + return 1; >> + >> + err = mmc_send_ext_csd(card, ext_csd); >> + if (err) >> + return err; >> + >> + return (ext_csd[EXT_CSD_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 a1223bd..514ad0f 100644 >> --- a/drivers/mmc/core/mmc.c >> +++ b/drivers/mmc/core/mmc.c >> @@ -448,6 +448,14 @@ 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 007863e..2e397d5 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); >> @@ -568,7 +572,7 @@ int mmc_send_hpi_cmd(struct mmc_card *card, u32 >> *status) >> >> err = mmc_wait_for_cmd(card->host, &cmd, 0); >> if (err) { >> - pr_warn("%s: error %d interrupting operation. " >> + pr_debug("%s: error %d interrupting operation. " >> "HPI command response %#x\n", >> mmc_hostname(card->host), >> err, cmd.resp[0]); >> return err; >> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h >> index 534974c..3c983d7 100644 >> --- a/include/linux/mmc/card.h >> +++ b/include/linux/mmc/card.h >> @@ -70,6 +70,8 @@ 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 >> */ >> u8 raw_partition_support; /* 160 */ >> u8 raw_erased_mem_count; /* 181 */ >> @@ -84,6 +86,7 @@ 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; >> @@ -209,6 +212,8 @@ 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 >> */ >> @@ -370,6 +375,8 @@ static inline void __maybe_unused >> remove_quirk(struct >> mmc_card *card, int data) >> #define mmc_card_uhs(c) ((c)->state & >> MMC_STATE_ULTRAHIGHSPEED) >> #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) >> @@ -379,6 +386,11 @@ static inline void __maybe_unused >> remove_quirk(struct >> mmc_card *card, int data) >> #define mmc_card_set_uhs(c) ((c)->state |= MMC_STATE_ULTRAHIGHSPEED) >> #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..f6b997a 100644 >> --- a/include/linux/mmc/core.h >> +++ b/include/linux/mmc/core.h >> @@ -134,6 +134,8 @@ struct mmc_host; >> struct mmc_card; >> struct mmc_async_req; >> >> +extern int mmc_interrupt_bkops(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 +165,7 @@ 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 706f722..4629e84 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..20b1420 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_ERASE_GROUP_DEF 175 /* R/W */ >> @@ -310,9 +314,11 @@ 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 */ >> >> /* >> @@ -373,4 +379,12 @@ 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 >> */ >> >> +/* >> + * 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 */ >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
