RE: [RFC PATCH] mmc: support background operation

[Seungwon Jeon <tgih.jun@samsung.com>]

Hi Jaehoon Chung,

Jaehoon Chung wrote:
> 
> Hi mailing.
> 
> This RFC patch is supported background operation(BKOPS).
> And if you want to test this patch, must apply "[PATCH v3] mmc: support
> HPI send command"
> 
> This patch is based on Hanumath Prasad's patch "mmc: enable background
> operations for emmc4.41 with HPI support"
> Hanumath's patch is implemented before applied per forlin's patch "use
> nonblock mmc request...".
> This patch is based on 3.1.0-rc1 in mmc-next.
> 
> Background operations is run when set the URGENT_BKOPS in response.
> 
> if set the URGENT_BKOPS in response, we can notify that card need the
> BKOPS.
> (URGENT_BKOPS is used in eMMC4.41 spec, but in eMMC4.5 changed to
> EXCEPTION_EVENT bit.
>  maybe, we need to change this point).
> 
> And all request is done, then run background operation.
> if request read/write operation when running BKOPS, issue HPI interrupt
> 
> This patch is just RFC patch (not to merge), because i want to use BKOPS
> in userspace.
> (using ioctl).
> 
> I want to get mailing's review for this patch.
> 
> 
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> CC: Hanumath Prasad <hanumath.prasad@stericsson.com>
> 
> ---
>  drivers/mmc/card/block.c   |    4 ++++
>  drivers/mmc/card/queue.c   |   10 ++++++++++
>  drivers/mmc/core/core.c    |   35 +++++++++++++++++++++++++++++++++++
>  drivers/mmc/core/mmc.c     |   28 ++++++++++++++++++++++++++++
>  drivers/mmc/core/mmc_ops.c |    3 +++
>  include/linux/mmc/card.h   |   11 +++++++++++
>  include/linux/mmc/core.h   |    1 +
>  include/linux/mmc/mmc.h    |    4 ++++
>  8 files changed, 96 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 1ff5486..ff72c4a 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -1078,6 +1078,10 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq,
> struct request *rqc)
>  		switch (status) {
>  		case MMC_BLK_SUCCESS:
>  		case MMC_BLK_PARTIAL:
> +			if (mmc_card_mmc(card) &&
> +				(brq->cmd.resp[0] & R1_URGENT_BKOPS)) {
> +				mmc_card_set_need_bkops(card);
> +			}
>  			/*
>  			 * A block was successfully transferred.
>  			 */
> diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
> index 45fb362..52b1293 100644
> --- a/drivers/mmc/card/queue.c
> +++ b/drivers/mmc/card/queue.c
> @@ -46,6 +46,8 @@ static int mmc_queue_thread(void *d)
>  {
>  	struct mmc_queue *mq = d;
>  	struct request_queue *q = mq->queue;
> +	struct mmc_card *card = mq->card;
> +	unsigned long flags;
> 
>  	current->flags |= PF_MEMALLOC;
> 
> @@ -61,6 +63,13 @@ static int mmc_queue_thread(void *d)
>  		spin_unlock_irq(q->queue_lock);
> 
>  		if (req || mq->mqrq_prev->req) {
> +			if (mmc_card_doing_bkops(card)) {
> +				mmc_interrupt_hpi(card);
> +				spin_lock_irqsave(&card->host->lock, flags);
> +				mmc_card_clr_doing_bkops(card);
> +				spin_unlock_irqrestore(&card->host->lock,
> +						flags);
> +			}
>  			set_current_state(TASK_RUNNING);
>  			mq->issue_fn(mq, req);
>  		} else {
> @@ -68,6 +77,7 @@ 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 7c1ab06..b6de0e5 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -347,6 +347,41 @@ int mmc_wait_for_cmd(struct mmc_host *host, struct
> mmc_command *cmd, int retries
> 
>  EXPORT_SYMBOL(mmc_wait_for_cmd);
> 
> +/* Start background operation */
> +void mmc_start_bkops(struct mmc_card *card)
> +{
> +	int err;
> +	unsigned long flags;
> +
> +	BUG_ON(!card);
> +
> +	if (!card->ext_csd.bkops_en) {
> +		printk(KERN_INFO "Didn't set BKOPS enable bit!\n");
> +		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) {
> +		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);
> +
>  /**
>   *	mmc_interrupt_hpi - Issue for High priority Interrupt
>   *	@card: the MMC card associated with the HPI transfer
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index ef10bfd..0372414 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -421,6 +421,17 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8
> *ext_csd)
>  				ext_csd[EXT_CSD_OUT_OF_INTERRUPT_TIME] * 10;
>  		}
> 
> +		/*
> +		 * check whether the eMMC card support BKOPS.
> +		 * if set BKOPS_SUPPORT bit,
> +		 * BKOPS_STATUS, BKOPS_EN,,BKOPS_START and
> +		 * URGENT_BKOPS are supported.(default)
> +		 */
> +		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.rel_param = ext_csd[EXT_CSD_WR_REL_PARAM];
>  	}
> 
> @@ -762,6 +773,23 @@ static int mmc_init_card(struct mmc_host *host, u32
> ocr,
>  	}
> 
>  	/*
> +	 * 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;
> +	}
> +
There is no code for enabling BKOPS_EN?
If host want to handle background operation manually, it needs. 

> +	/*
>  	 * 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 4706400..2a54221 100644
> --- a/drivers/mmc/core/mmc_ops.c
> +++ b/drivers/mmc/core/mmc_ops.c
> @@ -398,6 +398,9 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index,
> u8 value,
>  	if (err)
>  		return err;
> 
> +	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 411054d..137887d 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -67,6 +67,8 @@ struct mmc_ext_csd {
>  	bool			hpi_en;			/* HPI enablebit */
>  	bool			hpi;			/* HPI support bit */
>  	unsigned int		hpi_cmd;		/* cmd used as HPI */
> +	bool			bkops;			/* BKOPS support bit */
> +	bool			bkops_en;		/* BKOPS enable bit */
>  	u8			raw_partition_support;	/* 160 */
>  	u8			raw_erased_mem_count;	/* 181 */
>  	u8			raw_ext_csd_structure;	/* 194 */
> @@ -192,6 +194,8 @@ struct mmc_card {
>  #define MMC_QUIRK_DISABLE_CD	(1<<5)		/* disconnect CD/DAT[3]
> resistor */
>  #define MMC_QUIRK_INAND_CMD38	(1<<6)		/* iNAND devices have
> broken CMD38 */
>  #define MMC_QUIRK_BLK_NO_CMD23	(1<<7)		/* Avoid CMD23 for regular
> multiblock */
> +#define MMC_STATE_NEED_BKOPS	(1<<7)		/* Need background
> operation */
> +#define MMC_STATE_DOING_BKOPS	(1<<8)		/* Do running background
> operation */
> 
>  	unsigned int		erase_size;	/* erase size in sectors */
>   	unsigned int		erase_shift;	/* if erase unit is power 2 */
> @@ -318,6 +322,8 @@ 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)
> @@ -326,6 +332,11 @@ 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 dca3c08..90f2e1c 100644
> --- a/include/linux/mmc/core.h
> +++ b/include/linux/mmc/core.h
> @@ -162,6 +162,7 @@ extern int mmc_erase_group_aligned(struct mmc_card
> *card, unsigned int from,
>  				   unsigned int nr);
>  extern unsigned int mmc_calc_max_discard(struct mmc_card *card);
> 
> +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 e16c776..419a48e 100644
> --- a/include/linux/mmc/mmc.h
> +++ b/include/linux/mmc/mmc.h
> @@ -139,6 +139,7 @@ static inline bool mmc_op_multi(u32 opcode)
>  #define R1_READY_FOR_DATA	(1 << 8)	/* sx, a */
>  #define R1_SWITCH_ERROR		(1 << 7)	/* sx, c */
>  #define R1_APP_CMD		(1 << 5)	/* sr, c */
> +#define R1_URGENT_BKOPS		(1 << 6)	/* sr, a */
> 
>  #define R1_STATE_IDLE	0
>  #define R1_STATE_READY	1
> @@ -273,6 +274,8 @@ 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	/* R/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 */
> @@ -295,6 +298,7 @@ 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 */
> 
>  /*
> --
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