On 08/12/2011 04:14 AM, 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.
I'm a little confused by this statement. Was this patch done before Per
Forlin's work, or is this patch the implementation of the infrastructure
Per Forlin worked on to do non-blocking requests to the host controller?
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@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park<kyungmin.park@xxxxxxxxxxx>
CC: Hanumath Prasad<hanumath.prasad@xxxxxxxxxxxxxx>
---
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)
Is it possible to follow the kernel documentation standard for comment
function headers (I believe Randy Dunlap has given links to this in the
past)? You can see in this patch that after this function the next
function is using a function comment header per kernel guidelines.
+{
+ int err;
+ unsigned long flags;
+
+ BUG_ON(!card);
+
+ if (!card->ext_csd.bkops_en) {
+ printk(KERN_INFO "Didn't set BKOPS enable bit!\n");
I know that if new drivers are added to the kernel, maintainers will
reject the work if it's using printk()'s. If this code is getting new
functions, is it a good idea to start using the more modern, accepted
coding functions like pr_info()?
+ return;
+ }
+
+ if (mmc_card_doing_bkops(card) ||
+ !mmc_card_need_bkops(card)) {
This code wouldn't pass the checkpatch.pl tool; I've been burned by the
Linux community of having brackets around a single line of code.
+ 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) {
That is kind of an ugly if() statement; a bit further down I explain my
reasons for making if() statements like this more readable.
+ 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) {
I know some people prefer doing things like
A.'if (x)'
instead of
B.'if (x != NULL)
because A. is supposed to be some type of 'expert way' of doing things.
However, B. is a whole lot more readable and easier for people to
decipher precisely what is going on, especially newer people that may
not be as familiar with this part of the Linux kernel as others. Just
looking at this patch, I can't tell if 'card->ext_csd.hpi' is supposed
to be a number value or a pointer. And if you use Linus's tool 'sparse'
to check your kernel code before submitting, there is a difference
between statements like 'if (x == 0)' and 'if (x == NULL)', even though
they could evaluate to the same result in this if() statement.
So I suggest adding the equality or inequality sign to this if() as well
as any other if() to make the code a bit easier to understand.
+ 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 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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--
J (James/Jay) Freyensee
Storage Technology Group
Intel Corporation
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