Discussion:
[PATCH v12] mmc: support BKOPS feature for eMMC
Jaehoon Chung
2012-09-17 08:42:02 UTC
Permalink
Enable eMMC background operations (BKOPS) feature.

If URGENT_BKOPS is set after a response, note that BKOPS
are required. Immediately run BKOPS if required.
read/write operations should be requested during BKOPS(LEVEL-1),
then issue HPI to interrupt the ongoing BKOPS
and service the foreground operation.
(This patch is only control the LEVEL2/3.)

When repeating the writing 1GB data, at a certain time, performance is decreased.
At that time, card is also triggered the Level-3 or Level-2.
After running bkops, performance is recovered.

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?)
* If use periodic bkops, also consider runtime_pm control.

Signed-off-by: Jaehoon Chung <***@samsung.com>
Signed-off-by: Kyungmin Park <***@samsung.com>
Signed-off-by: Konstantin Dorfman <***@codeaurora.org>
Reviewed-by: Maya Erez <***@codeaurora.org>
---
Changelog v12:
- use the kamlloc for allocating the ext_csd.
: If use the periodic bkops, it should be modified.
Changelog v11:
- removed the MMC_CAP2_BKOPS.
: if card support and enable bkops, then use it.
Changelog v10:
- Based on latest mmc-next
- Only control the level-2/3.
: If triggered upper than level2, immediately start bkops.
- Remove the BKOPS_CAP2_INIT_BKOPS (move into mmc-util)
- change use_busy_signal instead of waiting_for_prog_done for __mmc_switch
- Remove the useless code.
- Add the from_exception to prepare the periodic bkops.
Changelog V9:
- Rebased on patch-v7.
- Added Konstantin and Maya's patch
: mmc:core: Define synchronous BKOPS timeout
: mmc:core: eMMC4.5 BKOPS fixes
- Removed periodic bkops
: This feature will do in future work
- Add __mmc_switch() for waiting_for_prod_done.

Changelog V8:
- Remove host->lock spin lock reviewed by Adrian
- Support periodic start bkops
- when bkops_status is level-3, if timeout is set to 0, send hpi.
- Move the start-bkops point
Changelog V7:
- Use HPI command when issued URGENT_BKOPS
- Recheck until clearing the bkops-status bit.
Changelog V6:
- Add the flag of check-bkops-status.
(For fixing async_req problem)
- Add the capability for MMC_CAP2_INIT_BKOPS.
(When unset the bkops_en bit in ext_csd register)
- modify the wrong condition.
Changelog V5:
- Rebase based on the latest mmc-next.
- modify codes based-on Chris's comment
Changelog V4:
- Add mmc_read_bkops_status
- When URGENT_BKOPS(level2-3), didn't use HPI command.
- In mmc_switch(), use R1B/R1 according to level.
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)
---
drivers/mmc/core/core.c | 157 +++++++++++++++++++++++++++++++++++++++++++-
drivers/mmc/core/mmc.c | 11 +++
drivers/mmc/core/mmc_ops.c | 26 ++++++-
include/linux/mmc/card.h | 8 ++
include/linux/mmc/core.h | 4 +
include/linux/mmc/mmc.h | 19 +++++
6 files changed, 219 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index af2c4d2..4749557 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -26,6 +26,7 @@
#include <linux/suspend.h>
#include <linux/fault-inject.h>
#include <linux/random.h>
+#include <linux/slab.h>

#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
@@ -41,6 +42,12 @@
#include "sd_ops.h"
#include "sdio_ops.h"

+/*
+ * The Background operation can take a long time, depends on the house keeping
+ * operations the card has to peform
+ */
+#define MMC_BKOPS_MAX_TIMEOUT (4 * 60 * 1000) /* max time to wait in ms */
+
static struct workqueue_struct *workqueue;
static const unsigned freqs[] = { 400000, 300000, 200000, 100000 };

@@ -245,6 +252,70 @@ 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
+ * @form_exception: A flags to indicate if this function was
+ * called due to an exception raised by the card
+ *
+ * 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, bool from_exception)
+{
+ int err;
+ int timeout;
+ bool use_busy_signal;
+
+ BUG_ON(!card);
+
+ if (!card->ext_csd.bkops_en || mmc_card_doing_bkops(card))
+ return;
+
+ err = mmc_read_bkops_status(card);
+ if (err) {
+ pr_err("%s: Didn't read bkops status : %d\n",
+ mmc_hostname(card->host), err);
+ return;
+ }
+
+ if (!card->ext_csd.raw_bkops_status)
+ return;
+
+ if (card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2
+ && (from_exception))
+ return;
+
+ mmc_claim_host(card->host);
+ if (card->ext_csd.raw_bkops_status >= EXT_CSD_BKOPS_LEVEL_2) {
+ timeout = MMC_BKOPS_MAX_TIMEOUT;
+ use_busy_signal = true;
+ } else {
+ timeout = 0;
+ use_busy_signal = false;
+ }
+
+ err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+ EXT_CSD_BKOPS_START, 1, timeout, use_busy_signal);
+ if (err) {
+ pr_warn("%s: error %d starting bkops\n",
+ mmc_hostname(card->host), err);
+ goto out;
+ }
+
+ /*
+ * For urgent bkops status (LEVEL_2 and more)
+ * bkops executed synchronously, otherwise
+ * the operation is in progress
+ */
+ if (!use_busy_signal)
+ mmc_card_set_doing_bkops(card);
+out:
+ mmc_release_host(card->host);
+}
+EXPORT_SYMBOL(mmc_start_bkops);
+
static void mmc_wait_done(struct mmc_request *mrq)
{
complete(&mrq->completion);
@@ -354,6 +425,14 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
if (host->areq) {
mmc_wait_for_req_done(host, host->areq->mrq);
err = host->areq->err_check(host->card, host->areq);
+ /*
+ * Check BKOPS urgency for each R1 response
+ */
+ if (host->card && mmc_card_mmc(host->card) &&
+ ((mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1) ||
+ (mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1B)) &&
+ (host->areq->mrq->cmd->resp[0] & R1_EXCEPTION_EVENT))
+ mmc_start_bkops(host->card, true);
}

if (!err && areq)
@@ -490,6 +569,64 @@ int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries
EXPORT_SYMBOL(mmc_wait_for_cmd);

/**
+ * mmc_stop_bkops - stop ongoing BKOPS
+ * @card: MMC card to check BKOPS
+ *
+ * Send HPI command to stop 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_stop_bkops(struct mmc_card *card)
+{
+ int err = 0;
+
+ BUG_ON(!card);
+ err = mmc_interrupt_hpi(card);
+
+ /*
+ * if err is EINVAL, it's status that can't issue HPI.
+ * it should complete the BKOPS.
+ */
+ if (!err || (err == -EINVAL)) {
+ mmc_card_clr_doing_bkops(card);
+ err = 0;
+ }
+
+ return err;
+}
+EXPORT_SYMBOL(mmc_stop_bkops);
+
+int mmc_read_bkops_status(struct mmc_card *card)
+{
+ int err;
+ u8 *ext_csd;
+
+ /*
+ * In future work, we should be consider storing the entire ext_csd.
+ */
+ ext_csd = kmalloc(512, GFP_KERNEL);
+ if (!ext_csd) {
+ pr_err("%s: could not allocate a buffer to "
+ "receive the ext_csd.\n", mmc_hostname(card->host));
+ return -ENOMEM;
+ }
+
+ mmc_claim_host(card->host);
+ err = mmc_send_ext_csd(card, ext_csd);
+ mmc_release_host(card->host);
+ if (err)
+ goto out;
+
+ 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];
+out:
+ kfree(ext_csd);
+ return err;
+}
+EXPORT_SYMBOL(mmc_read_bkops_status);
+
+/**
* 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
@@ -2334,7 +2471,13 @@ int mmc_suspend_host(struct mmc_host *host)
mmc_bus_get(host);
if (host->bus_ops && !host->bus_dead) {

- if (host->bus_ops->suspend)
+ if (host->bus_ops->suspend) {
+ if (mmc_card_doing_bkops(host->card)) {
+ err = mmc_stop_bkops(host->card);
+ if (err)
+ goto out;
+ }
+ }
err = host->bus_ops->suspend(host);

if (err == -ENOSYS || !host->bus_ops->resume) {
@@ -2417,11 +2560,21 @@ int mmc_pm_notify(struct notifier_block *notify_block,
struct mmc_host *host = container_of(
notify_block, struct mmc_host, pm_notify);
unsigned long flags;
-
+ int err = 0;

switch (mode) {
case PM_HIBERNATION_PREPARE:
case PM_SUSPEND_PREPARE:
+ if (host->card && mmc_card_mmc(host->card) &&
+ mmc_card_doing_bkops(host->card)) {
+ err = mmc_stop_bkops(host->card);
+ if (err) {
+ pr_err("%s didn't stop bkops\n",
+ mmc_hostname(host));
+ return err;
+ }
+ mmc_card_clr_doing_bkops(host->card);
+ }

spin_lock_irqsave(&host->lock, flags);
host->rescan_disable = 1;
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 396b258..9c5caa6 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -463,6 +463,17 @@ 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];
+ if (!card->ext_csd.bkops_en)
+ pr_info("%s: Didn't set BKOPS_EN bit!\n",
+ mmc_hostname(card->host));
+ }
+
/* 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 0ed2cc5..be0a98c 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -367,18 +367,19 @@ int mmc_spi_set_crc(struct mmc_host *host, int use_crc)
}

/**
- * mmc_switch - modify EXT_CSD register
+ * __mmc_switch - modify EXT_CSD register
* @card: the MMC card associated with the data transfer
* @set: cmd set values
* @index: EXT_CSD register index
* @value: value to program into EXT_CSD register
* @timeout_ms: timeout (ms) for operation performed by register write,
* timeout of zero implies maximum possible timeout
+ * @use_busy_signal: use the busy signal as response type
*
* Modifies the EXT_CSD register for selected card.
*/
-int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
- unsigned int timeout_ms)
+int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
+ unsigned int timeout_ms, bool use_busy_signal)
{
int err;
struct mmc_command cmd = {0};
@@ -392,13 +393,23 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
(index << 16) |
(value << 8) |
set;
- cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
+ cmd.flags = MMC_CMD_AC;
+ if (use_busy_signal)
+ cmd.flags |= MMC_RSP_SPI_R1B | MMC_RSP_R1B;
+ else
+ cmd.flags |= MMC_RSP_SPI_R1 | MMC_RSP_R1;
+
+
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 unblocking command */
+ if (!use_busy_signal)
+ return 0;
+
/* Must check status to be sure of no errors */
do {
err = mmc_send_status(card, &status);
@@ -423,6 +434,13 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,

return 0;
}
+EXPORT_SYMBOL_GPL(__mmc_switch);
+
+int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
+ unsigned int timeout_ms)
+{
+ return __mmc_switch(card, set, index, value, timeout_ms, true);
+}
EXPORT_SYMBOL_GPL(mmc_switch);

int mmc_send_status(struct mmc_card *card, u32 *status)
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 4b27f9f..78cc3be 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -76,10 +76,13 @@ struct mmc_ext_csd {
bool hpi_en; /* HPI enablebit */
bool hpi; /* HPI support bit */
unsigned int hpi_cmd; /* cmd used as HPI */
+ bool bkops; /* background support bit */
+ bool bkops_en; /* background enable bit */
unsigned int data_sector_size; /* 512 bytes or 4KB */
unsigned int data_tag_unit_size; /* DATA TAG UNIT size */
unsigned int boot_ro_lock; /* ro lock support */
bool boot_ro_lockable;
+ u8 raw_exception_status; /* 53 */
u8 raw_partition_support; /* 160 */
u8 raw_erased_mem_count; /* 181 */
u8 raw_ext_csd_structure; /* 194 */
@@ -93,6 +96,7 @@ 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;
@@ -226,6 +230,7 @@ struct mmc_card {
#define MMC_CARD_REMOVED (1<<7) /* card has been removed */
#define MMC_STATE_HIGHSPEED_200 (1<<8) /* card is in HS200 mode */
#define MMC_STATE_SLEEP (1<<9) /* card is in sleep state */
+#define MMC_STATE_DOING_BKOPS (1<<10) /* 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 */
@@ -393,6 +398,7 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
#define mmc_card_ext_capacity(c) ((c)->state & MMC_CARD_SDXC)
#define mmc_card_removed(c) ((c) && ((c)->state & MMC_CARD_REMOVED))
#define mmc_card_is_sleep(c) ((c)->state & MMC_STATE_SLEEP)
+#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)
@@ -405,7 +411,9 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
#define mmc_card_set_ext_capacity(c) ((c)->state |= MMC_CARD_SDXC)
#define mmc_card_set_removed(c) ((c)->state |= MMC_CARD_REMOVED)
#define mmc_card_set_sleep(c) ((c)->state |= MMC_STATE_SLEEP)
+#define mmc_card_set_doing_bkops(c) ((c)->state |= MMC_STATE_DOING_BKOPS)

+#define mmc_card_clr_doing_bkops(c) ((c)->state &= ~MMC_STATE_DOING_BKOPS)
#define mmc_card_clr_sleep(c) ((c)->state &= ~MMC_STATE_SLEEP)
/*
* Quirk add/remove for MMC products.
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 1b431c7..9b9cdaf 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_stop_bkops(struct mmc_card *);
+extern int mmc_read_bkops_status(struct mmc_card *);
extern struct mmc_async_req *mmc_start_req(struct mmc_host *,
struct mmc_async_req *, int *);
extern int mmc_interrupt_hpi(struct mmc_card *);
@@ -142,6 +144,8 @@ extern int mmc_wait_for_cmd(struct mmc_host *, struct mmc_command *, int);
extern int mmc_app_cmd(struct mmc_host *, struct mmc_card *);
extern int mmc_wait_for_app_cmd(struct mmc_host *, struct mmc_card *,
struct mmc_command *, int);
+extern void mmc_start_bkops(struct mmc_card *card, bool from_exception);
+extern int __mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int, bool);
extern int mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int);

#define MMC_ERASE_ARG 0x00000000
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index d425cab..01e4b39 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_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
@@ -274,12 +275,15 @@ 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_EXP_EVENTS_STATUS 54 /* RO */
#define EXT_CSD_DATA_SECTOR_SIZE 61 /* R */
#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_BOOT_WP 173 /* R/W */
@@ -313,11 +317,13 @@ 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_TAG_UNIT_SIZE 498 /* RO */
#define EXT_CSD_DATA_TAG_SUPPORT 499 /* RO */
+#define EXT_CSD_BKOPS_SUPPORT 502 /* RO */
#define EXT_CSD_HPI_FEATURES 503 /* RO */

/*
@@ -378,6 +384,19 @@ struct _mmc_csd {
#define EXT_CSD_PWR_CL_8BIT_SHIFT 4
#define EXT_CSD_PWR_CL_4BIT_SHIFT 0
/*
+ * EXCEPTION_EVENT_STATUS field
+ */
+#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)
+
+/*
+ * BKOPS status level
+ */
+#define EXT_CSD_BKOPS_LEVEL_2 0x2
+
+/*
* MMC_SWITCH access modes
*/
--
1.7.4.1
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Chris Ball
2012-09-17 10:30:46 UTC
Permalink
Hi Jaehoon,
Post by Jaehoon Chung
@@ -2334,7 +2471,13 @@ int mmc_suspend_host(struct mmc_host *host)
mmc_bus_get(host);
if (host->bus_ops && !host->bus_dead) {
- if (host->bus_ops->suspend)
+ if (host->bus_ops->suspend) {
+ if (mmc_card_doing_bkops(host->card)) {
+ err = mmc_stop_bkops(host->card);
+ if (err)
+ goto out;
+ }
+ }
err = host->bus_ops->suspend(host);
if (err == -ENOSYS || !host->bus_ops->resume) {
Something's gone very wrong with the closing brace here. Maybe you want
the closing brace to be a line later than it is?

Thanks,

- Chris.
--
Chris Ball <***@laptop.org> <http://printf.net/>
One Laptop Per Child
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Jaehoon Chung
2012-09-17 10:38:06 UTC
Permalink
Dear Chris,
Post by Chris Ball
Hi Jaehoon,
Post by Jaehoon Chung
@@ -2334,7 +2471,13 @@ int mmc_suspend_host(struct mmc_host *host)
mmc_bus_get(host);
if (host->bus_ops && !host->bus_dead) {
- if (host->bus_ops->suspend)
+ if (host->bus_ops->suspend) {
+ if (mmc_card_doing_bkops(host->card)) {
+ err = mmc_stop_bkops(host->card);
+ if (err)
+ goto out;
+ }
+ }
err = host->bus_ops->suspend(host);
if (err == -ENOSYS || !host->bus_ops->resume) {
Something's gone very wrong with the closing brace here. Maybe you want
the closing brace to be a line later than it is?
Sorry. you're right. it's my mistake. I will fix this.

Best Regards,
Jaehoon Chung
Post by Chris Ball
Thanks,
- Chris.
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Jaehoon Chung
2012-09-17 10:44:08 UTC
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Enable eMMC background operations (BKOPS) feature.

If URGENT_BKOPS is set after a response, note that BKOPS
are required. Immediately run BKOPS if required.
read/write operations should be requested during BKOPS(LEVEL-1),
then issue HPI to interrupt the ongoing BKOPS
and service the foreground operation.
(This patch is only control the LEVEL2/3.)

When repeating the writing 1GB data, at a certain time, performance is decreased.
At that time, card is also triggered the Level-3 or Level-2.
After running bkops, performance is recovered.

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?)
* If use periodic bkops, also consider runtime_pm control.

Signed-off-by: Jaehoon Chung <***@samsung.com>
Signed-off-by: Kyungmin Park <***@samsung.com>
Signed-off-by: Konstantin Dorfman <***@codeaurora.org>
Reviewed-by: Maya Erez <***@codeaurora.org>
---
Changelog v12:
- use the kamlloc for allocating the ext_csd.
: If use the periodic bkops, it should be modified.
Changelog v11:
- removed the MMC_CAP2_BKOPS.
: if card support and enable bkops, then use it.
Changelog v10:
- Based on latest mmc-next
- Only control the level-2/3.
: If triggered upper than level2, immediately start bkops.
- Remove the BKOPS_CAP2_INIT_BKOPS (move into mmc-util)
- change use_busy_signal instead of waiting_for_prog_done for __mmc_switch
- Remove the useless code.
- Add the from_exception to prepare the periodic bkops.
Changelog V9:
- Rebased on patch-v7.
- Added Konstantin and Maya's patch
: mmc:core: Define synchronous BKOPS timeout
: mmc:core: eMMC4.5 BKOPS fixes
- Removed periodic bkops
: This feature will do in future work
- Add __mmc_switch() for waiting_for_prod_done.

Changelog V8:
- Remove host->lock spin lock reviewed by Adrian
- Support periodic start bkops
- when bkops_status is level-3, if timeout is set to 0, send hpi.
- Move the start-bkops point
Changelog V7:
- Use HPI command when issued URGENT_BKOPS
- Recheck until clearing the bkops-status bit.
Changelog V6:
- Add the flag of check-bkops-status.
(For fixing async_req problem)
- Add the capability for MMC_CAP2_INIT_BKOPS.
(When unset the bkops_en bit in ext_csd register)
- modify the wrong condition.
Changelog V5:
- Rebase based on the latest mmc-next.
- modify codes based-on Chris's comment
Changelog V4:
- Add mmc_read_bkops_status
- When URGENT_BKOPS(level2-3), didn't use HPI command.
- In mmc_switch(), use R1B/R1 according to level.
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)
---
drivers/mmc/core/core.c | 157 +++++++++++++++++++++++++++++++++++++++++++-
drivers/mmc/core/mmc.c | 11 +++
drivers/mmc/core/mmc_ops.c | 26 ++++++-
include/linux/mmc/card.h | 8 ++
include/linux/mmc/core.h | 4 +
include/linux/mmc/mmc.h | 19 +++++
6 files changed, 219 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index af2c4d2..28ad74e 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -26,6 +26,7 @@
#include <linux/suspend.h>
#include <linux/fault-inject.h>
#include <linux/random.h>
+#include <linux/slab.h>

#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
@@ -41,6 +42,12 @@
#include "sd_ops.h"
#include "sdio_ops.h"

+/*
+ * The Background operation can take a long time, depends on the house keeping
+ * operations the card has to peform
+ */
+#define MMC_BKOPS_MAX_TIMEOUT (4 * 60 * 1000) /* max time to wait in ms */
+
static struct workqueue_struct *workqueue;
static const unsigned freqs[] = { 400000, 300000, 200000, 100000 };

@@ -245,6 +252,70 @@ 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
+ * @form_exception: A flags to indicate if this function was
+ * called due to an exception raised by the card
+ *
+ * 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, bool from_exception)
+{
+ int err;
+ int timeout;
+ bool use_busy_signal;
+
+ BUG_ON(!card);
+
+ if (!card->ext_csd.bkops_en || mmc_card_doing_bkops(card))
+ return;
+
+ err = mmc_read_bkops_status(card);
+ if (err) {
+ pr_err("%s: Didn't read bkops status : %d\n",
+ mmc_hostname(card->host), err);
+ return;
+ }
+
+ if (!card->ext_csd.raw_bkops_status)
+ return;
+
+ if (card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2
+ && (from_exception))
+ return;
+
+ mmc_claim_host(card->host);
+ if (card->ext_csd.raw_bkops_status >= EXT_CSD_BKOPS_LEVEL_2) {
+ timeout = MMC_BKOPS_MAX_TIMEOUT;
+ use_busy_signal = true;
+ } else {
+ timeout = 0;
+ use_busy_signal = false;
+ }
+
+ err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+ EXT_CSD_BKOPS_START, 1, timeout, use_busy_signal);
+ if (err) {
+ pr_warn("%s: error %d starting bkops\n",
+ mmc_hostname(card->host), err);
+ goto out;
+ }
+
+ /*
+ * For urgent bkops status (LEVEL_2 and more)
+ * bkops executed synchronously, otherwise
+ * the operation is in progress
+ */
+ if (!use_busy_signal)
+ mmc_card_set_doing_bkops(card);
+out:
+ mmc_release_host(card->host);
+}
+EXPORT_SYMBOL(mmc_start_bkops);
+
static void mmc_wait_done(struct mmc_request *mrq)
{
complete(&mrq->completion);
@@ -354,6 +425,14 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
if (host->areq) {
mmc_wait_for_req_done(host, host->areq->mrq);
err = host->areq->err_check(host->card, host->areq);
+ /*
+ * Check BKOPS urgency for each R1 response
+ */
+ if (host->card && mmc_card_mmc(host->card) &&
+ ((mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1) ||
+ (mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1B)) &&
+ (host->areq->mrq->cmd->resp[0] & R1_EXCEPTION_EVENT))
+ mmc_start_bkops(host->card, true);
}

if (!err && areq)
@@ -490,6 +569,64 @@ int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries
EXPORT_SYMBOL(mmc_wait_for_cmd);

/**
+ * mmc_stop_bkops - stop ongoing BKOPS
+ * @card: MMC card to check BKOPS
+ *
+ * Send HPI command to stop 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_stop_bkops(struct mmc_card *card)
+{
+ int err = 0;
+
+ BUG_ON(!card);
+ err = mmc_interrupt_hpi(card);
+
+ /*
+ * if err is EINVAL, it's status that can't issue HPI.
+ * it should complete the BKOPS.
+ */
+ if (!err || (err == -EINVAL)) {
+ mmc_card_clr_doing_bkops(card);
+ err = 0;
+ }
+
+ return err;
+}
+EXPORT_SYMBOL(mmc_stop_bkops);
+
+int mmc_read_bkops_status(struct mmc_card *card)
+{
+ int err;
+ u8 *ext_csd;
+
+ /*
+ * In future work, we should be consider storing the entire ext_csd.
+ */
+ ext_csd = kmalloc(512, GFP_KERNEL);
+ if (!ext_csd) {
+ pr_err("%s: could not allocate a buffer to "
+ "receive the ext_csd.\n", mmc_hostname(card->host));
+ return -ENOMEM;
+ }
+
+ mmc_claim_host(card->host);
+ err = mmc_send_ext_csd(card, ext_csd);
+ mmc_release_host(card->host);
+ if (err)
+ goto out;
+
+ 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];
+out:
+ kfree(ext_csd);
+ return err;
+}
+EXPORT_SYMBOL(mmc_read_bkops_status);
+
+/**
* 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
@@ -2334,8 +2471,14 @@ int mmc_suspend_host(struct mmc_host *host)
mmc_bus_get(host);
if (host->bus_ops && !host->bus_dead) {

- if (host->bus_ops->suspend)
+ if (host->bus_ops->suspend) {
+ if (mmc_card_doing_bkops(host->card)) {
+ err = mmc_stop_bkops(host->card);
+ if (err)
+ goto out;
+ }
err = host->bus_ops->suspend(host);
+ }

if (err == -ENOSYS || !host->bus_ops->resume) {
/*
@@ -2417,11 +2560,21 @@ int mmc_pm_notify(struct notifier_block *notify_block,
struct mmc_host *host = container_of(
notify_block, struct mmc_host, pm_notify);
unsigned long flags;
-
+ int err = 0;

switch (mode) {
case PM_HIBERNATION_PREPARE:
case PM_SUSPEND_PREPARE:
+ if (host->card && mmc_card_mmc(host->card) &&
+ mmc_card_doing_bkops(host->card)) {
+ err = mmc_stop_bkops(host->card);
+ if (err) {
+ pr_err("%s didn't stop bkops\n",
+ mmc_hostname(host));
+ return err;
+ }
+ mmc_card_clr_doing_bkops(host->card);
+ }

spin_lock_irqsave(&host->lock, flags);
host->rescan_disable = 1;
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 396b258..9c5caa6 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -463,6 +463,17 @@ 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];
+ if (!card->ext_csd.bkops_en)
+ pr_info("%s: Didn't set BKOPS_EN bit!\n",
+ mmc_hostname(card->host));
+ }
+
/* 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 0ed2cc5..be0a98c 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -367,18 +367,19 @@ int mmc_spi_set_crc(struct mmc_host *host, int use_crc)
}

/**
- * mmc_switch - modify EXT_CSD register
+ * __mmc_switch - modify EXT_CSD register
* @card: the MMC card associated with the data transfer
* @set: cmd set values
* @index: EXT_CSD register index
* @value: value to program into EXT_CSD register
* @timeout_ms: timeout (ms) for operation performed by register write,
* timeout of zero implies maximum possible timeout
+ * @use_busy_signal: use the busy signal as response type
*
* Modifies the EXT_CSD register for selected card.
*/
-int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
- unsigned int timeout_ms)
+int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
+ unsigned int timeout_ms, bool use_busy_signal)
{
int err;
struct mmc_command cmd = {0};
@@ -392,13 +393,23 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
(index << 16) |
(value << 8) |
set;
- cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
+ cmd.flags = MMC_CMD_AC;
+ if (use_busy_signal)
+ cmd.flags |= MMC_RSP_SPI_R1B | MMC_RSP_R1B;
+ else
+ cmd.flags |= MMC_RSP_SPI_R1 | MMC_RSP_R1;
+
+
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 unblocking command */
+ if (!use_busy_signal)
+ return 0;
+
/* Must check status to be sure of no errors */
do {
err = mmc_send_status(card, &status);
@@ -423,6 +434,13 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,

return 0;
}
+EXPORT_SYMBOL_GPL(__mmc_switch);
+
+int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
+ unsigned int timeout_ms)
+{
+ return __mmc_switch(card, set, index, value, timeout_ms, true);
+}
EXPORT_SYMBOL_GPL(mmc_switch);

int mmc_send_status(struct mmc_card *card, u32 *status)
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 4b27f9f..78cc3be 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -76,10 +76,13 @@ struct mmc_ext_csd {
bool hpi_en; /* HPI enablebit */
bool hpi; /* HPI support bit */
unsigned int hpi_cmd; /* cmd used as HPI */
+ bool bkops; /* background support bit */
+ bool bkops_en; /* background enable bit */
unsigned int data_sector_size; /* 512 bytes or 4KB */
unsigned int data_tag_unit_size; /* DATA TAG UNIT size */
unsigned int boot_ro_lock; /* ro lock support */
bool boot_ro_lockable;
+ u8 raw_exception_status; /* 53 */
u8 raw_partition_support; /* 160 */
u8 raw_erased_mem_count; /* 181 */
u8 raw_ext_csd_structure; /* 194 */
@@ -93,6 +96,7 @@ 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;
@@ -226,6 +230,7 @@ struct mmc_card {
#define MMC_CARD_REMOVED (1<<7) /* card has been removed */
#define MMC_STATE_HIGHSPEED_200 (1<<8) /* card is in HS200 mode */
#define MMC_STATE_SLEEP (1<<9) /* card is in sleep state */
+#define MMC_STATE_DOING_BKOPS (1<<10) /* 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 */
@@ -393,6 +398,7 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
#define mmc_card_ext_capacity(c) ((c)->state & MMC_CARD_SDXC)
#define mmc_card_removed(c) ((c) && ((c)->state & MMC_CARD_REMOVED))
#define mmc_card_is_sleep(c) ((c)->state & MMC_STATE_SLEEP)
+#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)
@@ -405,7 +411,9 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
#define mmc_card_set_ext_capacity(c) ((c)->state |= MMC_CARD_SDXC)
#define mmc_card_set_removed(c) ((c)->state |= MMC_CARD_REMOVED)
#define mmc_card_set_sleep(c) ((c)->state |= MMC_STATE_SLEEP)
+#define mmc_card_set_doing_bkops(c) ((c)->state |= MMC_STATE_DOING_BKOPS)

+#define mmc_card_clr_doing_bkops(c) ((c)->state &= ~MMC_STATE_DOING_BKOPS)
#define mmc_card_clr_sleep(c) ((c)->state &= ~MMC_STATE_SLEEP)
/*
* Quirk add/remove for MMC products.
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 1b431c7..9b9cdaf 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_stop_bkops(struct mmc_card *);
+extern int mmc_read_bkops_status(struct mmc_card *);
extern struct mmc_async_req *mmc_start_req(struct mmc_host *,
struct mmc_async_req *, int *);
extern int mmc_interrupt_hpi(struct mmc_card *);
@@ -142,6 +144,8 @@ extern int mmc_wait_for_cmd(struct mmc_host *, struct mmc_command *, int);
extern int mmc_app_cmd(struct mmc_host *, struct mmc_card *);
extern int mmc_wait_for_app_cmd(struct mmc_host *, struct mmc_card *,
struct mmc_command *, int);
+extern void mmc_start_bkops(struct mmc_card *card, bool from_exception);
+extern int __mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int, bool);
extern int mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int);

#define MMC_ERASE_ARG 0x00000000
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index d425cab..01e4b39 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_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
@@ -274,12 +275,15 @@ 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_EXP_EVENTS_STATUS 54 /* RO */
#define EXT_CSD_DATA_SECTOR_SIZE 61 /* R */
#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_BOOT_WP 173 /* R/W */
@@ -313,11 +317,13 @@ 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_TAG_UNIT_SIZE 498 /* RO */
#define EXT_CSD_DATA_TAG_SUPPORT 499 /* RO */
+#define EXT_CSD_BKOPS_SUPPORT 502 /* RO */
#define EXT_CSD_HPI_FEATURES 503 /* RO */

/*
@@ -378,6 +384,19 @@ struct _mmc_csd {
#define EXT_CSD_PWR_CL_8BIT_SHIFT 4
#define EXT_CSD_PWR_CL_4BIT_SHIFT 0
/*
+ * EXCEPTION_EVENT_STATUS field
+ */
+#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)
+
+/*
+ * BKOPS status level
+ */
+#define EXT_CSD_BKOPS_LEVEL_2 0x2
+
+/*
* MMC_SWITCH access modes
*/
--
1.7.4.1


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Chris Ball
2012-09-17 12:21:38 UTC
Permalink
Hi Jaehoon,
Post by Jaehoon Chung
Enable eMMC background operations (BKOPS) feature.
If URGENT_BKOPS is set after a response, note that BKOPS
are required. Immediately run BKOPS if required.
read/write operations should be requested during BKOPS(LEVEL-1),
then issue HPI to interrupt the ongoing BKOPS
and service the foreground operation.
(This patch is only control the LEVEL2/3.)
When repeating the writing 1GB data, at a certain time, performance is decreased.
At that time, card is also triggered the Level-3 or Level-2.
After running bkops, performance is recovered.
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?)
* If use periodic bkops, also consider runtime_pm control.
Thanks, looks good now. Is it okay if I apply this stylistic patch
before pushing to mmc-next?


diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 4749557..044cd01 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -43,8 +43,8 @@
#include "sdio_ops.h"

/*
- * The Background operation can take a long time, depends on the house keeping
- * operations the card has to peform
+ * Background operations can take a long time, depending on the housekeeping
+ * operations the card has to perform.
*/
#define MMC_BKOPS_MAX_TIMEOUT (4 * 60 * 1000) /* max time to wait in ms */

@@ -255,11 +255,11 @@ mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
/**
* mmc_start_bkops - start BKOPS for supported cards
* @card: MMC card to start BKOPS
- * @form_exception: A flags to indicate if this function was
- * called due to an exception raised by the card
+ * @form_exception: A flag to indicate if this function was
+ * called due to an exception raised by the card
*
* Start background operations whenever requested.
- * when the urgent BKOPS bit is set in a R1 command response
+ * 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, bool from_exception)
@@ -275,7 +275,7 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)

err = mmc_read_bkops_status(card);
if (err) {
- pr_err("%s: Didn't read bkops status : %d\n",
+ pr_err("%s: Failed to read bkops status: %d\n",
mmc_hostname(card->host), err);
return;
}
@@ -283,8 +283,8 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)
if (!card->ext_csd.raw_bkops_status)
return;

- if (card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2
- && (from_exception))
+ if (card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2 &&
+ from_exception)
return;

mmc_claim_host(card->host);
@@ -299,8 +299,8 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_BKOPS_START, 1, timeout, use_busy_signal);
if (err) {
- pr_warn("%s: error %d starting bkops\n",
- mmc_hostname(card->host), err);
+ pr_warn("%s: Error %d starting bkops\n",
+ mmc_hostname(card->host), err);
goto out;
}

@@ -429,9 +429,9 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
* Check BKOPS urgency for each R1 response
*/
if (host->card && mmc_card_mmc(host->card) &&
- ((mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1) ||
- (mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1B)) &&
- (host->areq->mrq->cmd->resp[0] & R1_EXCEPTION_EVENT))
+ ((mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1) ||
+ (mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1B)) &&
+ (host->areq->mrq->cmd->resp[0] & R1_EXCEPTION_EVENT))
mmc_start_bkops(host->card, true);
}

@@ -477,7 +477,7 @@ EXPORT_SYMBOL(mmc_wait_for_req);
* @card: the MMC card associated with the HPI transfer
*
* Issued High Priority Interrupt, and check for card status
- * util out-of prg-state.
+ * until out-of prg-state.
*/
int mmc_interrupt_hpi(struct mmc_card *card)
{
@@ -572,8 +572,8 @@ EXPORT_SYMBOL(mmc_wait_for_cmd);
* mmc_stop_bkops - stop ongoing BKOPS
* @card: MMC card to check BKOPS
*
- * Send HPI command to stop ongoing background operations,
- * to allow rapid servicing of foreground operations,e.g. read/
+ * Send HPI command to stop 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.
*/
@@ -585,8 +585,8 @@ int mmc_stop_bkops(struct mmc_card *card)
err = mmc_interrupt_hpi(card);

/*
- * if err is EINVAL, it's status that can't issue HPI.
- * it should complete the BKOPS.
+ * If err is EINVAL, we can't issue an HPI.
+ * It should complete the BKOPS.
*/
if (!err || (err == -EINVAL)) {
mmc_card_clr_doing_bkops(card);
@@ -603,12 +603,12 @@ int mmc_read_bkops_status(struct mmc_card *card)
u8 *ext_csd;

/*
- * In future work, we should be consider storing the entire ext_csd.
+ * In future work, we should consider storing the entire ext_csd.
*/
ext_csd = kmalloc(512, GFP_KERNEL);
if (!ext_csd) {
- pr_err("%s: could not allocate a buffer to "
- "receive the ext_csd.\n", mmc_hostname(card->host));
+ pr_err("%s: could not allocate buffer to receive the ext_csd.\n",
+ mmc_hostname(card->host));
return -ENOMEM;
}

@@ -2470,15 +2470,14 @@ int mmc_suspend_host(struct mmc_host *host)

mmc_bus_get(host);
if (host->bus_ops && !host->bus_dead) {
-
if (host->bus_ops->suspend) {
if (mmc_card_doing_bkops(host->card)) {
err = mmc_stop_bkops(host->card);
if (err)
goto out;
}
- }
err = host->bus_ops->suspend(host);
+ }

if (err == -ENOSYS || !host->bus_ops->resume) {
/*
@@ -2566,10 +2565,10 @@ int mmc_pm_notify(struct notifier_block *notify_block,
case PM_HIBERNATION_PREPARE:
case PM_SUSPEND_PREPARE:
if (host->card && mmc_card_mmc(host->card) &&
- mmc_card_doing_bkops(host->card)) {
+ mmc_card_doing_bkops(host->card)) {
err = mmc_stop_bkops(host->card);
if (err) {
- pr_err("%s didn't stop bkops\n",
+ pr_err("%s: didn't stop bkops\n",
mmc_hostname(host));
return err;
}
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 9c5caa6..7509de1 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -463,15 +463,15 @@ 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 */
+ /* check whether the eMMC card supports 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)
- pr_info("%s: Didn't set BKOPS_EN bit!\n",
- mmc_hostname(card->host));
+ pr_info("%s: BKOPS_EN bit is not set\n",
+ mmc_hostname(card->host));
}

/* check whether the eMMC card supports HPI */
--
Chris Ball <***@laptop.org> <http://printf.net/>
One Laptop Per Child
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Jaehoon Chung
2012-09-17 23:36:00 UTC
Permalink
Post by Chris Ball
Hi Jaehoon,
Post by Jaehoon Chung
Enable eMMC background operations (BKOPS) feature.
If URGENT_BKOPS is set after a response, note that BKOPS
are required. Immediately run BKOPS if required.
read/write operations should be requested during BKOPS(LEVEL-1),
then issue HPI to interrupt the ongoing BKOPS
and service the foreground operation.
(This patch is only control the LEVEL2/3.)
When repeating the writing 1GB data, at a certain time, performance is decreased.
At that time, card is also triggered the Level-3 or Level-2.
After running bkops, performance is recovered.
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?)
* If use periodic bkops, also consider runtime_pm control.
Thanks, looks good now. Is it okay if I apply this stylistic patch
before pushing to mmc-next?
Sure, Thanks Chris.

Best Regards,
Jaehoon Chung
Post by Chris Ball
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 4749557..044cd01 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -43,8 +43,8 @@
#include "sdio_ops.h"
/*
- * The Background operation can take a long time, depends on the house keeping
- * operations the card has to peform
+ * Background operations can take a long time, depending on the housekeeping
+ * operations the card has to perform.
*/
#define MMC_BKOPS_MAX_TIMEOUT (4 * 60 * 1000) /* max time to wait in ms */
@@ -255,11 +255,11 @@ mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
/**
* mmc_start_bkops - start BKOPS for supported cards
- * called due to an exception raised by the card
+ * called due to an exception raised by the card
*
* Start background operations whenever requested.
- * when the urgent BKOPS bit is set in a R1 command response
+ * 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, bool from_exception)
@@ -275,7 +275,7 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)
err = mmc_read_bkops_status(card);
if (err) {
- pr_err("%s: Didn't read bkops status : %d\n",
+ pr_err("%s: Failed to read bkops status: %d\n",
mmc_hostname(card->host), err);
return;
}
@@ -283,8 +283,8 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)
if (!card->ext_csd.raw_bkops_status)
return;
- if (card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2
- && (from_exception))
+ if (card->ext_csd.raw_bkops_status < EXT_CSD_BKOPS_LEVEL_2 &&
+ from_exception)
return;
mmc_claim_host(card->host);
@@ -299,8 +299,8 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_BKOPS_START, 1, timeout, use_busy_signal);
if (err) {
- pr_warn("%s: error %d starting bkops\n",
- mmc_hostname(card->host), err);
+ pr_warn("%s: Error %d starting bkops\n",
+ mmc_hostname(card->host), err);
goto out;
}
@@ -429,9 +429,9 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
* Check BKOPS urgency for each R1 response
*/
if (host->card && mmc_card_mmc(host->card) &&
- ((mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1) ||
- (mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1B)) &&
- (host->areq->mrq->cmd->resp[0] & R1_EXCEPTION_EVENT))
+ ((mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1) ||
+ (mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1B)) &&
+ (host->areq->mrq->cmd->resp[0] & R1_EXCEPTION_EVENT))
mmc_start_bkops(host->card, true);
}
@@ -477,7 +477,7 @@ EXPORT_SYMBOL(mmc_wait_for_req);
*
* Issued High Priority Interrupt, and check for card status
- * util out-of prg-state.
+ * until out-of prg-state.
*/
int mmc_interrupt_hpi(struct mmc_card *card)
{
@@ -572,8 +572,8 @@ EXPORT_SYMBOL(mmc_wait_for_cmd);
* mmc_stop_bkops - stop ongoing BKOPS
*
- * Send HPI command to stop ongoing background operations,
- * to allow rapid servicing of foreground operations,e.g. read/
+ * Send HPI command to stop 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.
*/
@@ -585,8 +585,8 @@ int mmc_stop_bkops(struct mmc_card *card)
err = mmc_interrupt_hpi(card);
/*
- * if err is EINVAL, it's status that can't issue HPI.
- * it should complete the BKOPS.
+ * If err is EINVAL, we can't issue an HPI.
+ * It should complete the BKOPS.
*/
if (!err || (err == -EINVAL)) {
mmc_card_clr_doing_bkops(card);
@@ -603,12 +603,12 @@ int mmc_read_bkops_status(struct mmc_card *card)
u8 *ext_csd;
/*
- * In future work, we should be consider storing the entire ext_csd.
+ * In future work, we should consider storing the entire ext_csd.
*/
ext_csd = kmalloc(512, GFP_KERNEL);
if (!ext_csd) {
- pr_err("%s: could not allocate a buffer to "
- "receive the ext_csd.\n", mmc_hostname(card->host));
+ pr_err("%s: could not allocate buffer to receive the ext_csd.\n",
+ mmc_hostname(card->host));
return -ENOMEM;
}
@@ -2470,15 +2470,14 @@ int mmc_suspend_host(struct mmc_host *host)
mmc_bus_get(host);
if (host->bus_ops && !host->bus_dead) {
-
if (host->bus_ops->suspend) {
if (mmc_card_doing_bkops(host->card)) {
err = mmc_stop_bkops(host->card);
if (err)
goto out;
}
- }
err = host->bus_ops->suspend(host);
+ }
if (err == -ENOSYS || !host->bus_ops->resume) {
/*
@@ -2566,10 +2565,10 @@ int mmc_pm_notify(struct notifier_block *notify_block,
if (host->card && mmc_card_mmc(host->card) &&
- mmc_card_doing_bkops(host->card)) {
+ mmc_card_doing_bkops(host->card)) {
err = mmc_stop_bkops(host->card);
if (err) {
- pr_err("%s didn't stop bkops\n",
+ pr_err("%s: didn't stop bkops\n",
mmc_hostname(host));
return err;
}
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 9c5caa6..7509de1 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -463,15 +463,15 @@ 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 */
+ /* check whether the eMMC card supports 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)
- pr_info("%s: Didn't set BKOPS_EN bit!\n",
- mmc_hostname(card->host));
+ pr_info("%s: BKOPS_EN bit is not set\n",
+ mmc_hostname(card->host));
}
/* check whether the eMMC card supports HPI */
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