mmc: support BKOPS feature for eMMC v4.5
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 BKOPS-STATUS is upper than LEVEL2, need to check until clear
the BKOPS-STATUS vaule.
If you want to enable this feature, set MMC_CAP2_BKOPS.
And if you want to set the BKOPS_EN bit in ext_csd register,
use the MMC_CAP2_INIT_BKOPS.
Future considerations
* Check BKOPS_LEVEL=1 and start BKOPS in a preventive manner.
* Interrupt ongoing BKOPS before powering off the card.
* How get BKOPS_STATUS value.(periodically send ext_csd command?)
Change-Id: Ia679c661a282072a7e54d10fc59d8ec1cbecae96
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index d1b9010..6ce7cbb 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1227,6 +1227,13 @@
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))
+ mmc_card_set_check_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 760e9aa..a8409c8 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -67,6 +67,9 @@
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 {
@@ -74,6 +77,8 @@
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 15ddd83..91c37e5 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -223,6 +223,62 @@
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 (mmc_card_check_bkops(card)) {
+ spin_lock_irqsave(&card->host->lock, flags);
+ mmc_card_clr_check_bkops(card);
+ spin_unlock_irqrestore(&card->host->lock, flags);
+ if (mmc_is_exception_event(card, EXT_CSD_URGENT_BKOPS))
+ if (card->ext_csd.raw_bkops_status)
+ mmc_card_set_need_bkops(card);
+ }
+
+ /*
+ * 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("%s: error %d starting bkops\n",
+ mmc_hostname(card->host), 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);
+ if (card->ext_csd.raw_bkops_status >= EXT_CSD_BKOPS_LEVEL_2)
+ mmc_card_set_check_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);
@@ -451,6 +507,69 @@
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_read_bkops_status(struct mmc_card *card)
+{
+ int err;
+ u8 ext_csd[512];
+
+ mmc_claim_host(card->host);
+ err = mmc_send_ext_csd(card, ext_csd);
+ mmc_release_host(card->host);
+ if (err)
+ return err;
+
+ card->ext_csd.raw_bkops_status = ext_csd[EXT_CSD_BKOPS_STATUS];
+ card->ext_csd.raw_exception_status = ext_csd[EXT_CSD_EXP_EVENTS_STATUS];
+
+ return 0;
+}
+EXPORT_SYMBOL(mmc_read_bkops_status);
+
+int mmc_is_exception_event(struct mmc_card *card, unsigned int value)
+{
+ int err;
+
+ err = mmc_read_bkops_status(card);
+ if (err) {
+ pr_err("%s: Didn't read bkops status : %d\n",
+ mmc_hostname(card->host), err);
+ return 0;
+ }
+
+ /* In eMMC 4.41, R1_EXCEPTION_EVENT is URGENT_BKOPS */
+ if (card->ext_csd.rev == 5)
+ return 1;
+
+ return (card->ext_csd.raw_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 8fce9a6..6178097 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -425,6 +425,24 @@
}
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];
+ if (!card->ext_csd.bkops_en &&
+ card->host->caps2 & MMC_CAP2_INIT_BKOPS) {
+ err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+ EXT_CSD_BKOPS_EN, 1, 0);
+ if (err)
+ pr_warning("%s: Enabling BKOPS failed\n",
+ mmc_hostname(card->host));
+ else
+ card->ext_csd.bkops_en = 1;
+ }
+ }
+
/* 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 2438176..0d3c77b 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -391,13 +391,22 @@
(index << 16) |
(value << 8) |
set;
- cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
+ cmd.flags = MMC_CMD_AC;
+ if (index == EXT_CSD_BKOPS_START &&
+ card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2)
+ cmd.flags |= MMC_RSP_SPI_R1 | MMC_RSP_R1;
+ else
+ cmd.flags |= MMC_RSP_SPI_R1B | MMC_RSP_R1B;
cmd.cmd_timeout_ms = timeout_ms;
err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);
if (err)
return err;
+ /* No need to check card status in case of BKOPS switch*/
+ if (index == EXT_CSD_BKOPS_START)
+ return 0;
+
mmc_delay(1);
/* Must check status to be sure of no errors */
do {