Merge "mmc: support BKOPS feature for eMMC"
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 478cfac..9b316bb 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -28,6 +28,7 @@
 #include <linux/random.h>
 #include <linux/wakelock.h>
 #include <linux/pm.h>
+#include <linux/slab.h>
 
 #include <linux/mmc/card.h>
 #include <linux/mmc/host.h>
@@ -43,6 +44,12 @@
 #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;
 
 /*
@@ -272,6 +279,70 @@
 	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);
@@ -381,6 +452,14 @@
 	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)
@@ -425,7 +504,7 @@
  *	@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)
 {
@@ -507,6 +586,64 @@
 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
@@ -2370,8 +2507,14 @@
 				err = -EBUSY;
 
 		if (!err) {
-			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 stop_bkops_err;
+				}
 				err = host->bus_ops->suspend(host);
+			}
 			if (!(host->card && mmc_card_sdio(host->card)))
 				mmc_release_host(host);
 
@@ -2401,6 +2544,10 @@
 
 out:
 	return err;
+stop_bkops_err:
+	if (!(host->card && mmc_card_sdio(host->card)))
+		mmc_release_host(host);
+	return err;
 }
 
 EXPORT_SYMBOL(mmc_suspend_host);
@@ -2463,11 +2610,21 @@
 	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);
 		if (mmc_bus_needs_resume(host)) {
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index f87b8cc..6343760 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -463,6 +463,17 @@
 	}
 
 	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 e18d922..4f46ed1 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -368,18 +368,19 @@
 }
 
 /**
- *	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};
@@ -393,13 +394,23 @@
 		  (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);
@@ -424,6 +435,13 @@
 
 	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 a80eb59..87e06ed 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -79,10 +79,13 @@
 	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 */
@@ -96,6 +99,7 @@
 	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;
@@ -247,6 +251,7 @@
 #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 */
@@ -415,6 +420,7 @@
 #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)
@@ -427,7 +433,9 @@
 #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 817862f..3f26a80 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -138,6 +138,8 @@
 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 *);
@@ -146,6 +148,8 @@
 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);
 extern int mmc_send_ext_csd(struct mmc_card *card, u8 *ext_csd);
 
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index ce4d3c2..87cdba8 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -139,6 +139,7 @@
 #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_EXP_EVENT		(1 << 6)	/* sr, a */
 
@@ -286,6 +287,8 @@
 #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 */
@@ -319,6 +322,7 @@
 #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 */
@@ -326,6 +330,7 @@
 #define EXT_CSD_DATA_TAG_SUPPORT	499	/* RO */
 #define EXT_CSD_MAX_PACKED_WRITES	500	/* RO */
 #define EXT_CSD_MAX_PACKED_READS	501	/* RO */
+#define EXT_CSD_BKOPS_SUPPORT		502	/* RO */
 #define EXT_CSD_HPI_FEATURES		503	/* RO */
 
 /*
@@ -397,12 +402,23 @@
 
 #define EXT_CSD_PACKED_EVENT_EN	(1 << 3)
 
-#define EXT_CSD_PACKED_FAILURE	(1 << 3)
-
 #define EXT_CSD_PACKED_GENERIC_ERROR	(1 << 0)
 #define EXT_CSD_PACKED_INDEXED_ERROR	(1 << 1)
 
 /*
+ * 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
  */