Add the ability to partially initialize the MMC device by
using device sleep/awake sequence (CMD5).
Device will be sent to sleep state during mmc runtime/system suspend
and will be woken up during mmc runtime/system resume.
By using this sequence the device doesn't need full initialization
which gives 25% time reduction in system/runtime resume path.
1) Micron eMMC (ManfID 0x13)
Partial init Full Init
a) _mmc_resume: _mmc_resume :
Total time : 62ms Total time : 84ms
(Improvement % from full init = ~26%)
2) Kingston eMMC (ManfID 0x70)
Partial init Full Init
a) _mmc_resume: _mmc_resume :
Total time : 46ms Total time : 62ms
(Improvement % from full init = ~25%).
Co-developed-by: Veerabhadrarao Badiganti <quic_vbadigan@xxxxxxxxxxx>
Signed-off-by: Veerabhadrarao Badiganti <quic_vbadigan@xxxxxxxxxxx>
Signed-off-by: Sarthak Garg <quic_sartgarg@xxxxxxxxxxx>
---
drivers/mmc/core/mmc.c | 163 ++++++++++++++++++++++++++++++++++++---
include/linux/mmc/card.h | 4 +
include/linux/mmc/host.h | 2 +
3 files changed, 160 insertions(+), 9 deletions(-)
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 8180983bd402..fb33bcf6d360 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1956,7 +1956,28 @@ static int mmc_sleep_busy_cb(void *cb_data, bool *busy)
return 0;
}
-static int mmc_sleep(struct mmc_host *host)
+/*
+ * Returns true if card supports sleep/awake command and host can simply do
+ * sleep/awake instead of full card initialization as part of resume.
+ */
+static inline int mmc_can_sleepawake(struct mmc_host *host)
+{
+ return mmc_can_sleep(host->card) && (host->caps2 & MMC_CAP2_SLEEP_AWAKE);
+}
+
+/**
+ * mmc_sleepawake - function to sleep or awake the device
+ * @host: MMC host
+ * @sleep: if true then sleep command is sent else awake
+ *
+ * This function first deselects the card and then sends the sleep command
+ * in case of sleep whereas in case of awake first awake command is send
+ * and then the card is selected.
+ *
+ * Returns 0 on success, non-zero value on failure
+ */
+
+static int mmc_sleepawake(struct mmc_host *host, bool sleep)
{
struct mmc_command cmd = {};
struct mmc_card *card = host->card;
@@ -1967,14 +1988,17 @@ static int mmc_sleep(struct mmc_host *host)
/* Re-tuning can't be done once the card is deselected */
mmc_retune_hold(host);
- err = mmc_deselect_cards(host);
- if (err)
- goto out_release;
+ if (sleep) {
+ err = mmc_deselect_cards(host);
+ if (err)
+ goto out_release;
+ }
cmd.opcode = MMC_SLEEP_AWAKE;
cmd.arg = card->rca << 16;
- cmd.arg |= 1 << 15;
use_r1b_resp = mmc_prepare_busy_cmd(host, &cmd, timeout_ms);
+ if (sleep)
+ cmd.arg |= BIT(15);
err = mmc_wait_for_cmd(host, &cmd, 0);
if (err)
@@ -1997,6 +2021,9 @@ static int mmc_sleep(struct mmc_host *host)
err = __mmc_poll_for_busy(host, 0, timeout_ms, &mmc_sleep_busy_cb, host);
out_release:
+ if (!sleep)
+ err = mmc_select_card(card);
+
mmc_retune_release(host);
return err;
}
@@ -2094,6 +2121,73 @@ static int _mmc_flush_cache(struct mmc_host *host)
pr_err("%s: cache flush error %d\n",
mmc_hostname(host), err);
}
+ return err;
+}
+
+/*
+ * Save read/write fields of ext_csd register that the sw changes
+ * as part of suspend.
+ */
+static int mmc_save_card_ext_csd(struct mmc_host *host)
+{
+ int err;
+ u8 *ext_csd;
+ struct mmc_card *card = host->card;
+
+ err = mmc_get_ext_csd(card, &ext_csd);
+ if (err || !ext_csd) {
+ pr_err("%s: %s: mmc_get_ext_csd failed (%d)\n",
+ mmc_hostname(host), __func__, err);
+ return err;
+ }
+
+ card->ext_csd.raw_ext_csd_cmdq = ext_csd[EXT_CSD_CMDQ_MODE_EN];
+ card->ext_csd.raw_ext_csd_cache_ctrl = ext_csd[EXT_CSD_CACHE_CTRL];
+ card->ext_csd.raw_ext_csd_bus_width = ext_csd[EXT_CSD_BUS_WIDTH];
+ card->ext_csd.raw_ext_csd_hs_timing = ext_csd[EXT_CSD_HS_TIMING];
+
+ kfree(ext_csd);
+
+ return 0;
+}
+
+/*
+ * Get the ext_csd register from the card post resume and compare with
+ * read/write fields of ext_csd register that the sw changes.
+ */
+static int mmc_test_awake_ext_csd(struct mmc_host *host)
+{
+ struct mmc_card *card = host->card;
+ u8 *ext_csd;
+ int err;
+
+ err = mmc_get_ext_csd(card, &ext_csd);
+ if (err) {
+ pr_err("%s: %s: mmc_get_ext_csd failed (%d)\n",
+ mmc_hostname(host), __func__, err);
+ return err;
+ }
+
+ pr_debug("%s: %s: type(cached:current) cmdq(%d:%d) cache_ctrl(%d:%d) bus_width (%d:%d) timing(%d:%d)\n",
+ mmc_hostname(host), __func__,
+ card->ext_csd.raw_ext_csd_cmdq,
+ ext_csd[EXT_CSD_CMDQ_MODE_EN],
+ card->ext_csd.raw_ext_csd_cache_ctrl,
+ ext_csd[EXT_CSD_CACHE_CTRL],
+ card->ext_csd.raw_ext_csd_bus_width,
+ ext_csd[EXT_CSD_BUS_WIDTH],
+ card->ext_csd.raw_ext_csd_hs_timing,
+ ext_csd[EXT_CSD_HS_TIMING]);
+ err = !((card->ext_csd.raw_ext_csd_cmdq ==
+ ext_csd[EXT_CSD_CMDQ_MODE_EN]) &&
+ (card->ext_csd.raw_ext_csd_cache_ctrl ==
+ ext_csd[EXT_CSD_CACHE_CTRL]) &&
+ (card->ext_csd.raw_ext_csd_bus_width ==
+ ext_csd[EXT_CSD_BUS_WIDTH]) &&
+ (card->ext_csd.raw_ext_csd_hs_timing ==
+ ext_csd[EXT_CSD_HS_TIMING]));
+
+ kfree(ext_csd);
return err;
}
@@ -2117,9 +2211,15 @@ static int _mmc_suspend(struct mmc_host *host, bool is_suspend)
((host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) || !is_suspend ||
(host->caps2 & MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND)))
err = mmc_poweroff_notify(host->card, notify_type);
- else if (mmc_can_sleep(host->card))
- err = mmc_sleep(host);
- else if (!mmc_host_is_spi(host))
+ else if (mmc_can_sleep(host->card)) {
+ if (mmc_can_sleepawake(host)) {
+ memcpy(&host->cached_ios, &host->ios, sizeof(host->cached_ios));
+ err = mmc_save_card_ext_csd(host);
+ if (err)
+ goto out;
+ }
+ err = mmc_sleepawake(host, true);
+ } else if (!mmc_host_is_spi(host))
err = mmc_deselect_cards(host);
if (!err) {
@@ -2131,6 +2231,39 @@ static int _mmc_suspend(struct mmc_host *host, bool is_suspend)
return err;
}
+static int mmc_partial_init(struct mmc_host *host)
+{
+ int err = 0;
+ struct mmc_card *card = host->card;
+
+ mmc_set_bus_width(host, host->cached_ios.bus_width);
+ mmc_set_timing(host, host->cached_ios.timing);
+ if (host->cached_ios.enhanced_strobe) {
+ host->ios.enhanced_strobe = true;
+ if (host->ops->hs400_enhanced_strobe)
+ host->ops->hs400_enhanced_strobe(host, &host->ios);
+ }
+ mmc_set_clock(host, host->cached_ios.clock);
+ mmc_set_bus_mode(host, host->cached_ios.bus_mode);
+
+ if (!mmc_card_hs400es(card) &&
+ (mmc_card_hs200(card) || mmc_card_hs400(card))) {
+ err = mmc_execute_tuning(card);
+ if (err) {
+ pr_err("%s: %s: Tuning failed (%d)\n",
+ mmc_hostname(host), __func__, err);
+ goto out;
+ }
+ }
+
+ err = mmc_test_awake_ext_csd(host);
+ if (err)
+ pr_debug("%s: %s: fail on ext_csd read (%d)\n",
+ mmc_hostname(host), __func__, err);
+out:
+ return err;
+}
+
/*
* Suspend callback
*/
@@ -2161,7 +2294,19 @@ static int _mmc_resume(struct mmc_host *host)
goto out;
mmc_power_up(host, host->card->ocr);
- err = mmc_init_card(host, host->card->ocr, host->card);
+
+ if (mmc_can_sleepawake(host)) {
+ err = mmc_sleepawake(host, false);
+ if (!err)
+ err = mmc_partial_init(host);
+ else
+ pr_err("%s: %s: awake failed (%d), fallback to full init\n",
+ mmc_hostname(host), __func__, err);
+ }
+
+ if (!mmc_can_sleepawake(host) || err)
+ err = mmc_init_card(host, host->card->ocr, host->card);
+
mmc_card_clr_suspended(host->card);
out:
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index daa2f40d9ce6..fbc832ec6d57 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -86,6 +86,8 @@ struct mmc_ext_csd {
unsigned int data_tag_unit_size; /* DATA TAG UNIT size */
unsigned int boot_ro_lock; /* ro lock support */
bool boot_ro_lockable;
+ u8 raw_ext_csd_cmdq; /* 15 */
+ u8 raw_ext_csd_cache_ctrl; /* 33 */
bool ffu_capable; /* Firmware upgrade support */
bool cmdq_en; /* Command Queue enabled */
bool cmdq_support; /* Command Queue supported */
@@ -96,7 +98,9 @@ struct mmc_ext_csd {
u8 raw_partition_support; /* 160 */
u8 raw_rpmb_size_mult; /* 168 */
u8 raw_erased_mem_count; /* 181 */
+ u8 raw_ext_csd_bus_width; /* 183 */
u8 strobe_support; /* 184 */
+ u8 raw_ext_csd_hs_timing; /* 185 */
u8 raw_ext_csd_structure; /* 194 */
u8 raw_card_type; /* 196 */
u8 raw_driver_strength; /* 197 */
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 2f445c651742..836382a0b2e9 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -427,6 +427,7 @@ struct mmc_host {
#define MMC_CAP2_CRYPTO 0
#endif
#define MMC_CAP2_ALT_GPT_TEGRA (1 << 28) /* Host with eMMC that has GPT entry at a non-standard location */
+#define MMC_CAP2_SLEEP_AWAKE (1 << 29) /* Use Sleep/Awake (CMD5) */
int fixed_drv_type; /* fixed driver type for non-removable media */
@@ -445,6 +446,7 @@ struct mmc_host {
spinlock_t lock; /* lock for claim and bus ops */
struct mmc_ios ios; /* current io bus settings */
+ struct mmc_ios cached_ios;
/* group bitfields together to minimize padding */
unsigned int use_spi_crc:1;
--
2.17.1
