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authorJaehoon Chung <jh80.chung@samsung.com>2012-09-17 08:42:02 +0000
committerChris Ball <cjb@laptop.org>2012-10-03 10:05:12 -0400
commit950d56acce5d401f477b91d0177605b543d63d07 (patch)
tree205505f3976d02c6ef2fa9d6c911407f0e0f6c80 /drivers/mmc/core
parentbec9d4e5939987053169a9bb48fc58b6a2d3e237 (diff)
downloadop-kernel-dev-950d56acce5d401f477b91d0177605b543d63d07.zip
op-kernel-dev-950d56acce5d401f477b91d0177605b543d63d07.tar.gz
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. 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 only controls the LEVEL2/3.) When repeating the writing 1GB data, at a certain time, performance is decreased. At that time, card triggers 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 do we get BKOPS_STATUS value (periodically send ext_csd command)? * If using periodic bkops, also consider runtime_pm control. 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> Reviewed-by: Maya Erez <merez@codeaurora.org> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/core')
-rw-r--r--drivers/mmc/core/core.c160
-rw-r--r--drivers/mmc/core/mmc.c11
-rw-r--r--drivers/mmc/core/mmc_ops.c26
3 files changed, 189 insertions, 8 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index af2c4d2..044cd01 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"
+/*
+ * 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 */
+
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 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
+ * 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: Failed to 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)
@@ -398,7 +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)
{
@@ -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, we can't issue an 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 consider storing the entire ext_csd.
+ */
+ ext_csd = kmalloc(512, GFP_KERNEL);
+ if (!ext_csd) {
+ pr_err("%s: could not allocate 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
@@ -2333,9 +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 (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 +2559,21 @@ 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..7509de1 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 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: BKOPS_EN bit is not set\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 225371a..a0e1720 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -393,18 +393,19 @@ 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};
@@ -418,13 +419,23 @@ 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);
@@ -449,6 +460,13 @@ 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)
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