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. > 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. 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
