[PATCH RFC 00/46] mmc: mmc: Add Software Command Queuing

[PATCH RFC 00/46] mmc: mmc: Add Software Command Queuing

[Adrian Hunter]

Hi

Chuanxiao Dong sent some patches last year relating to eMMC 5.1 Software
Command Queuing.  He did not follow-up but I have contacted him and he says
it is OK if I take over upstreaming the patches.

eMMC Command Queuing is a feature added in version 5.1.  The card maintains
a queue of up to 32 data transfers.  Commands CMD45/CMD45 are sent to queue
up transfers in advance, and then one of the transfers is selected to
"execute" by CMD46/CMD47 at which point data transfer actually begins.

The advantage of command queuing is that the card can prepare for transfers
in advance.  That makes a big difference in the case of random reads because
the card can start reading into its cache in advance.

A v5.1 host controller can manage the command queue itself, but it is also
possible for software to manage the queue using an non-v5.1 host controller
- that is what Software Command Queuing is.

Refer to the JEDEC (http://www.jedec.org/) eMMC v5.1 Specification for more
information about Command Queuing.

While these patches are heavily based on Dong's patches, there are some
changes:

SDHCI has been amended to support commands during transfer. That is a
generic change added in patches 1 - 22. In principle, that would also
support SDIO's CMD52 during data transfer.

The original approach added multiple commands into the same request for
sending CMD44, CMD45 and CMD13. That is not strictly necessary and has
been omitted for now.

The original approach also called blk_end_request() from the mrq->done()
function, which means the upper layers learnt of completed requests
slightly earlier. That is not strictly related to Software Command Queuing
and is something that could potentially be done for all data requests.
That has been omitted for now.

The current block driver supports 2 requests on the go at a time. Patches
23 - 30 make preparations for an arbitrary sized queue. Patches 31 - 34
introduce Command Queue definitions and helpers.  Patches 35 - 41
complete the job of making the block driver use a queue.  Patches 42 - 44
finally add Software Command Queuing, and 45 - 46 enable it for Intel eMMC
controllers. Most of the Software Command Queuing functionality is added
in patch 43.

The patches can also be found here:

	http://git.infradead.org/users/ahunter/linux-sdhci.git/shortlog/refs/heads/swcmdq

The patches have only had basic testing so far. Ad-hoc testing shows a
degradation in sequential read performance of about 10% but an increase in
throughput for mixed workload of multiple processes of about 90%. The
reduction in sequential performance is due to the need to read the Queue
Status register between each transfer.

These patches should not conflict with Hardware Command Queuing which
handles the queue in a completely different way and thus does not need
to share code with Software Command Queuing. The exceptions being the
Command Queue definitions and queue allocation which should be able to be
used.


Adrian Hunter (46):
      mmc: core: Add support for sending commands during data transfer
      mmc: mmc_test: Add tests for sending commands during transfer
      mmc: sdhci: Move busy signal handling into sdhci_finish_cmd()
      mmc: sdhci: Get rid of redundant BUG_ONs
      mmc: sdhci: Simplify sdhci_finish_command() by clearing host->cmd at the start
      mmc: sdhci: Record what command is using the data lines
      mmc: sdhci: Get rid of host->busy_handle
      mmc: sdhci: Reduce the use of host->mrq
      mmc: sdhci: Move host->data warning
      mmc: sdhci: Factor out sdhci_finish_mrq()
      mmc: sdhci: Factor out sdhci_needs_reset()
      mmc: sdhci: Track whether a reset is pending
      mmc: sdhci: Clear pointers when a request finishes
      mmc: sdhci: Ensure all requests get errored out
      mmc: sdhci: Factor out sdhci_data_line_cmd()
      mmc: sdhci: Separate timer timeout for command and data requests
      mmc: sdhci: Allow for finishing multiple requests
      mmc: sdhci: Factor out sdhci_auto_cmd12()
      mmc: sdhci: Do not reset cmd or data circuits that are in use
      mmc: sdhci: Support cap_cmd_during_tfr requests
      mmc: sdhci-pci: Set MMC_CAP_CMD_DURING_TFR for Intel eMMC controllers
      mmc: sdhci-acpi: Set MMC_CAP_CMD_DURING_TFR for Intel eMMC controllers
      mmc: queue: Fix queue thread wake-up
      mmc: queue: Factor out mmc_queue_alloc_bounce_bufs()
      mmc: queue: Factor out mmc_queue_alloc_bounce_sgs()
      mmc: queue: Factor out mmc_queue_alloc_sgs()
      mmc: queue: Factor out mmc_queue_reqs_free_bufs()
      mmc: queue: Introduce queue depth
      mmc: queue: Use queue depth to allocate and free
      mmc: queue: Allocate queue of size qdepth
      mmc: mmc: Add Command Queue definitions
      mmc: mmc: Add functions to enable / disable the Command Queue
      mmc: mmc_test: Disable Command Queue while mmc_test is used
      mmc: block: Disable Command Queue while RPMB is used
      mmc: core: Do not prepare a new request twice
      mmc: core: Export mmc_retune_hold() and mmc_retune_release()
      mmc: block: Factor out mmc_blk_requeue()
      mmc: block: Fix 4K native sector check
      mmc: block: Use local var for mqrq_cur
      mmc: block: Pass mqrq to mmc_blk_prep_packed_list()
      mmc: block: Introduce queue semantics
      mmc: queue: Add a function to control wake-up on new requests
      mmc: block: Add Software Command Queuing
      mmc: mmc: Enable Software Command Queuing
      mmc: sdhci-pci: Enable Software Command Queuing for some Intel controllers
      mmc: sdhci-acpi: Enable Software Command Queuing for some Intel controllers

 drivers/mmc/card/block.c          | 738 +++++++++++++++++++++++++++++++++++---
 drivers/mmc/card/mmc_test.c       | 316 ++++++++++++++++
 drivers/mmc/card/queue.c          | 296 +++++++++------
 drivers/mmc/card/queue.h          |  27 +-
 drivers/mmc/core/core.c           | 113 +++++-
 drivers/mmc/core/host.c           |   2 +
 drivers/mmc/core/host.h           |   2 -
 drivers/mmc/core/mmc.c            |  43 ++-
 drivers/mmc/core/mmc_ops.c        |  27 ++
 drivers/mmc/host/sdhci-acpi.c     |   4 +-
 drivers/mmc/host/sdhci-pci-core.c |   1 +
 drivers/mmc/host/sdhci.c          | 391 +++++++++++++-------
 drivers/mmc/host/sdhci.h          |   9 +-
 include/linux/mmc/card.h          |   5 +
 include/linux/mmc/core.h          |  12 +
 include/linux/mmc/host.h          |   9 +-
 include/linux/mmc/mmc.h           |  17 +
 17 files changed, 1686 insertions(+), 326 deletions(-)


Regards
Adrian

[PATCH RFC 01/46] mmc: core: Add support for sending commands during data transfer

[Adrian Hunter]

A host controller driver exposes its capability using caps flag
MMC_CAP_CMD_DURING_TFR. A driver with that capability can accept requests
that are marked mrq->cap_cmd_during_tfr = true. Then the driver informs the
upper layers when the command line is available for further commands by
calling mmc_command_done(). Because of that, the driver will not then
automatically send STOP commands, and it is the responsibility of the upper
layer to send a STOP command if it is required.

For requests submitted through the mmc_wait_for_req() interface, the caller
sets mrq->cap_cmd_during_tfr = true which causes mmc_wait_for_req() in fact
not to wait. The caller can then send commands that do not use the data
lines. Finally the caller can wait for the transfer to complete by calling
mmc_wait_for_req_done() which is now exported.

For requests submitted through the mmc_start_req() interface, the caller
again sets mrq->cap_cmd_during_tfr = true, but mmc_start_req() anyway does
not wait. The caller can then send commands that do not use the data
lines. Finally the caller can wait for the transfer to complete in the
normal way i.e. calling mmc_start_req() again.

Irrespective of how a cap_cmd_during_tfr request is started,
mmc_is_req_done() can be called if the upper layer needs to determine if
the request is done. However the appropriate waiting function (either
mmc_wait_for_req_done() or mmc_start_req()) must still be called.

The implementation consists primarily of a new completion
mrq->cmd_completion which notifies when the command line is available for
further commands. That completion is completed by mmc_command_done().
When there is an ongoing data transfer, calls to mmc_wait_for_req() will
automatically wait on that completion, so the caller does not have to do
anything special.

Note, in the case of errors, the driver may call mmc_request_done() without
calling mmc_command_done() because mmc_request_done() always calls
mmc_command_done().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/core/core.c  | 95 +++++++++++++++++++++++++++++++++++++++++++++---
 include/linux/mmc/core.h |  7 ++++
 include/linux/mmc/host.h |  5 +++
 3 files changed, 101 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index e8641873dee7..8563dc9e1519 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -117,6 +117,24 @@ static inline void mmc_should_fail_request(struct mmc_host *host,
 
 #endif /* CONFIG_FAIL_MMC_REQUEST */
 
+static inline void mmc_complete_cmd(struct mmc_request *mrq)
+{
+	if (mrq->cap_cmd_during_tfr && !completion_done(&mrq->cmd_completion))
+		complete_all(&mrq->cmd_completion);
+}
+
+void mmc_command_done(struct mmc_host *host, struct mmc_request *mrq)
+{
+	if (!mrq->cap_cmd_during_tfr)
+		return;
+
+	mmc_complete_cmd(mrq);
+
+	pr_debug("%s: cmd done, tfr ongoing (CMD%u)\n",
+		 mmc_hostname(host), mrq->cmd->opcode);
+}
+EXPORT_SYMBOL(mmc_command_done);
+
 /**
  *	mmc_request_done - finish processing an MMC request
  *	@host: MMC host which completed request
@@ -143,6 +161,11 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
 			cmd->retries = 0;
 	}
 
+	if (host->ongoing_mrq == mrq)
+		host->ongoing_mrq = NULL;
+
+	mmc_complete_cmd(mrq);
+
 	trace_mmc_request_done(host, mrq);
 
 	if (err && cmd->retries && !mmc_card_removed(host->card)) {
@@ -155,7 +178,8 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
 	} else {
 		mmc_should_fail_request(host, mrq);
 
-		led_trigger_event(host->led, LED_OFF);
+		if (!host->ongoing_mrq)
+			led_trigger_event(host->led, LED_OFF);
 
 		if (mrq->sbc) {
 			pr_debug("%s: req done <CMD%u>: %d: %08x %08x %08x %08x\n",
@@ -220,6 +244,15 @@ static void __mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
 		}
 	}
 
+	if (mrq->cap_cmd_during_tfr) {
+		host->ongoing_mrq = mrq;
+		/*
+		 * Retry path could come through here without having waiting on
+		 * cmd_completion, so ensure it is reinitialised.
+		 */
+		reinit_completion(&mrq->cmd_completion);
+	}
+
 	trace_mmc_request_start(host, mrq);
 
 	host->ops->request(host, mrq);
@@ -386,6 +419,18 @@ static void mmc_wait_done(struct mmc_request *mrq)
 	complete(&mrq->completion);
 }
 
+static inline void mmc_wait_ongoing_tfr_cmd(struct mmc_host *host)
+{
+	struct mmc_request *ongoing_mrq = READ_ONCE(host->ongoing_mrq);
+
+	/*
+	 * If there is an ongoing transfer, wait for the command line to become
+	 * available.
+	 */
+	if (ongoing_mrq && !completion_done(&ongoing_mrq->cmd_completion))
+		wait_for_completion(&ongoing_mrq->cmd_completion);
+}
+
 /*
  *__mmc_start_data_req() - starts data request
  * @host: MMC host to start the request
@@ -393,17 +438,24 @@ static void mmc_wait_done(struct mmc_request *mrq)
  *
  * Sets the done callback to be called when request is completed by the card.
  * Starts data mmc request execution
+ * If an ongoing transfer is already in progress, wait for the command line
+ * to become available before sending another command.
  */
 static int __mmc_start_data_req(struct mmc_host *host, struct mmc_request *mrq)
 {
 	int err;
 
+	mmc_wait_ongoing_tfr_cmd(host);
+
 	mrq->done = mmc_wait_data_done;
 	mrq->host = host;
 
+	init_completion(&mrq->cmd_completion);
+
 	err = mmc_start_request(host, mrq);
 	if (err) {
 		mrq->cmd->error = err;
+		mmc_complete_cmd(mrq);
 		mmc_wait_data_done(mrq);
 	}
 
@@ -414,12 +466,17 @@ static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq)
 {
 	int err;
 
+	mmc_wait_ongoing_tfr_cmd(host);
+
 	init_completion(&mrq->completion);
 	mrq->done = mmc_wait_done;
 
+	init_completion(&mrq->cmd_completion);
+
 	err = mmc_start_request(host, mrq);
 	if (err) {
 		mrq->cmd->error = err;
+		mmc_complete_cmd(mrq);
 		complete(&mrq->completion);
 	}
 
@@ -483,8 +540,7 @@ static int mmc_wait_for_data_req_done(struct mmc_host *host,
 	return err;
 }
 
-static void mmc_wait_for_req_done(struct mmc_host *host,
-				  struct mmc_request *mrq)
+void mmc_wait_for_req_done(struct mmc_host *host, struct mmc_request *mrq)
 {
 	struct mmc_command *cmd;
 
@@ -525,6 +581,28 @@ static void mmc_wait_for_req_done(struct mmc_host *host,
 
 	mmc_retune_release(host);
 }
+EXPORT_SYMBOL(mmc_wait_for_req_done);
+
+/**
+ *	mmc_is_req_done - Determine if a 'cap_cmd_during_tfr' request is done
+ *	@host: MMC host
+ *	@mrq: MMC request
+ *
+ *	mmc_is_req_done() is used with requests that have
+ *	mrq->cap_cmd_during_tfr = true. mmc_is_req_done() must be called after
+ *	starting a request and before waiting for it to complete. That is,
+ *	either in between calls to mmc_start_req(), or after mmc_wait_for_req()
+ *	and before mmc_wait_for_req_done(). If it is called at other times the
+ *	result is not meaningful.
+ */
+bool mmc_is_req_done(struct mmc_host *host, struct mmc_request *mrq)
+{
+	if (host->areq)
+		return host->context_info.is_done_rcv;
+	else
+		return completion_done(&mrq->completion);
+}
+EXPORT_SYMBOL(mmc_is_req_done);
 
 /**
  *	mmc_pre_req - Prepare for a new request
@@ -645,13 +723,18 @@ EXPORT_SYMBOL(mmc_start_req);
  *	@mrq: MMC request to start
  *
  *	Start a new MMC custom command request for a host, and wait
- *	for the command to complete. Does not attempt to parse the
- *	response.
+ *	for the command to complete. In the case of 'cap_cmd_during_tfr'
+ *	requests, the transfer is ongoing and the caller can issue further
+ *	commands that do not use the data lines, and then wait by calling
+ *	mmc_wait_for_req_done().
+ *	Does not attempt to parse the response.
  */
 void mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq)
 {
 	__mmc_start_req(host, mrq);
-	mmc_wait_for_req_done(host, mrq);
+
+	if (!mrq->cap_cmd_during_tfr)
+		mmc_wait_for_req_done(host, mrq);
 }
 EXPORT_SYMBOL(mmc_wait_for_req);
 
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index b01e77de1a74..368bed70aa9d 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -133,8 +133,12 @@ struct mmc_request {
 	struct mmc_command	*stop;
 
 	struct completion	completion;
+	struct completion	cmd_completion;
 	void			(*done)(struct mmc_request *);/* completion function */
 	struct mmc_host		*host;
+
+	/* Allow other commands during this ongoing data transfer or busy wait */
+	bool			cap_cmd_during_tfr;
 };
 
 struct mmc_card;
@@ -146,6 +150,9 @@ extern struct mmc_async_req *mmc_start_req(struct mmc_host *,
 					   struct mmc_async_req *, int *);
 extern int mmc_interrupt_hpi(struct mmc_card *);
 extern void mmc_wait_for_req(struct mmc_host *, struct mmc_request *);
+extern void mmc_wait_for_req_done(struct mmc_host *host,
+				  struct mmc_request *mrq);
+extern bool mmc_is_req_done(struct mmc_host *host, struct mmc_request *mrq);
 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 *,
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index d72c0c34c21d..af247e4c75d5 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -281,6 +281,7 @@ struct mmc_host {
 #define MMC_CAP_DRIVER_TYPE_A	(1 << 23)	/* Host supports Driver Type A */
 #define MMC_CAP_DRIVER_TYPE_C	(1 << 24)	/* Host supports Driver Type C */
 #define MMC_CAP_DRIVER_TYPE_D	(1 << 25)	/* Host supports Driver Type D */
+#define MMC_CAP_CMD_DURING_TFR	(1 << 29)	/* Commands during data transfer */
 #define MMC_CAP_CMD23		(1 << 30)	/* CMD23 supported. */
 #define MMC_CAP_HW_RESET	(1 << 31)	/* Hardware reset */
 
@@ -380,6 +381,9 @@ struct mmc_host {
 	struct mmc_async_req	*areq;		/* active async req */
 	struct mmc_context_info	context_info;	/* async synchronization info */
 
+	/* Ongoing data transfer that allows commands during transfer */
+	struct mmc_request	*ongoing_mrq;
+
 #ifdef CONFIG_FAIL_MMC_REQUEST
 	struct fault_attr	fail_mmc_request;
 #endif
@@ -416,6 +420,7 @@ int mmc_power_restore_host(struct mmc_host *host);
 
 void mmc_detect_change(struct mmc_host *, unsigned long delay);
 void mmc_request_done(struct mmc_host *, struct mmc_request *);
+void mmc_command_done(struct mmc_host *host, struct mmc_request *mrq);
 
 static inline void mmc_signal_sdio_irq(struct mmc_host *host)
 {
-- 
1.9.1

[PATCH RFC 02/46] mmc: mmc_test: Add tests for sending commands during transfer

[Adrian Hunter]

Add 6 tests for sending commands during transfer. The tests are:
 * Commands during read - no Set Block Count (CMD23).
 * Commands during write - no Set Block Count (CMD23).
 * Commands during read - use Set Block Count (CMD23).
 * Commands during write - use Set Block Count (CMD23).
 * Commands during non-blocking read - use Set Block Count (CMD23).
 * Commands during non-blocking write - use Set Block Count (CMD23).

For a range of transfer sizes, the tests start an ongoing data transfer and
then repeatedly send the status command (CMD13) while the transfer
continues. The tests pass if all requests complete with no errors. The host
controller driver must support MMC_CAP_CMD_DURING_TFR.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/mmc_test.c | 308 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 308 insertions(+)

diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
index c032eef45762..5a8dc5a76e0d 100644
--- a/drivers/mmc/card/mmc_test.c
+++ b/drivers/mmc/card/mmc_test.c
@@ -184,6 +184,29 @@ static int mmc_test_set_blksize(struct mmc_test_card *test, unsigned size)
 	return mmc_set_blocklen(test->card, size);
 }
 
+static bool mmc_test_card_cmd23(struct mmc_card *card)
+{
+	return mmc_card_mmc(card) ||
+	       (mmc_card_sd(card) && card->scr.cmds & SD_SCR_CMD23_SUPPORT);
+}
+
+static void mmc_test_prepare_sbc(struct mmc_test_card *test,
+				 struct mmc_request *mrq, unsigned int blocks)
+{
+	struct mmc_card *card = test->card;
+
+	if (!mrq->sbc || !mmc_host_cmd23(card->host) ||
+	    !mmc_test_card_cmd23(card) || !mmc_op_multi(mrq->cmd->opcode) ||
+	    (card->quirks & MMC_QUIRK_BLK_NO_CMD23)) {
+		mrq->sbc = NULL;
+		return;
+	}
+
+	mrq->sbc->opcode = MMC_SET_BLOCK_COUNT;
+	mrq->sbc->arg = blocks;
+	mrq->sbc->flags = MMC_RSP_R1 | MMC_CMD_AC;
+}
+
 /*
  * Fill in the mmc_request structure given a set of transfer parameters.
  */
@@ -221,6 +244,8 @@ static void mmc_test_prepare_mrq(struct mmc_test_card *test,
 	mrq->data->sg = sg;
 	mrq->data->sg_len = sg_len;
 
+	mmc_test_prepare_sbc(test, mrq, blocks);
+
 	mmc_set_data_timeout(mrq->data, test->card);
 }
 
@@ -693,6 +718,8 @@ static int mmc_test_check_result(struct mmc_test_card *test,
 
 	ret = 0;
 
+	if (mrq->sbc && mrq->sbc->error)
+		ret = mrq->sbc->error;
 	if (!ret && mrq->cmd->error)
 		ret = mrq->cmd->error;
 	if (!ret && mrq->data->error)
@@ -2278,6 +2305,245 @@ static int mmc_test_reset(struct mmc_test_card *test)
 	return RESULT_FAIL;
 }
 
+struct mmc_test_req {
+	struct mmc_request mrq;
+	struct mmc_command sbc;
+	struct mmc_command cmd;
+	struct mmc_command stop;
+	struct mmc_command status;
+	struct mmc_data data;
+};
+
+static struct mmc_test_req *mmc_test_req_alloc(void)
+{
+	struct mmc_test_req *rq = kzalloc(sizeof(*rq), GFP_KERNEL);
+
+	if (rq) {
+		rq->mrq.cmd = &rq->cmd;
+		rq->mrq.data = &rq->data;
+		rq->mrq.stop = &rq->stop;
+	}
+
+	return rq;
+}
+
+static int mmc_test_send_status(struct mmc_test_card *test,
+				struct mmc_command *cmd)
+{
+	memset(cmd, 0, sizeof(*cmd));
+
+	cmd->opcode = MMC_SEND_STATUS;
+	if (!mmc_host_is_spi(test->card->host))
+		cmd->arg = test->card->rca << 16;
+	cmd->flags = MMC_RSP_SPI_R2 | MMC_RSP_R1 | MMC_CMD_AC;
+
+	return mmc_wait_for_cmd(test->card->host, cmd, 0);
+}
+
+static int mmc_test_ongoing_transfer(struct mmc_test_card *test,
+				     unsigned int dev_addr, int use_sbc,
+				     int repeat_cmd, int write, int use_areq)
+{
+	struct mmc_test_req *rq = mmc_test_req_alloc();
+	struct mmc_host *host = test->card->host;
+	struct mmc_test_area *t = &test->area;
+	struct mmc_async_req areq;
+	struct mmc_request *mrq;
+	unsigned long timeout;
+	bool expired = false;
+	int ret = 0, cmd_ret;
+	u32 status = 0;
+	int count = 0;
+
+	if (!rq)
+		return -ENOMEM;
+
+	mrq = &rq->mrq;
+	if (use_sbc)
+		mrq->sbc = &rq->sbc;
+	mrq->cap_cmd_during_tfr = true;
+
+	areq.mrq = mrq;
+	areq.err_check = mmc_test_check_result_async;
+
+	mmc_test_prepare_mrq(test, mrq, t->sg, t->sg_len, dev_addr, t->blocks,
+			     512, write);
+
+	if (use_sbc && t->blocks > 1 && !mrq->sbc) {
+		ret =  mmc_host_cmd23(host) ?
+		       RESULT_UNSUP_CARD :
+		       RESULT_UNSUP_HOST;
+		goto out_free;
+	}
+
+	/* Start ongoing data request */
+	if (use_areq) {
+		mmc_start_req(host, &areq, &ret);
+		if (ret)
+			goto out_free;
+	} else {
+		mmc_wait_for_req(host, mrq);
+	}
+
+	timeout = jiffies + msecs_to_jiffies(3000);
+	do {
+		count += 1;
+
+		/* Send status command while data transfer in progress */
+		cmd_ret = mmc_test_send_status(test, &rq->status);
+		if (cmd_ret)
+			break;
+
+		status = rq->status.resp[0];
+		if (status & R1_ERROR) {
+			cmd_ret = -EIO;
+			break;
+		}
+
+		if (mmc_is_req_done(host, mrq))
+			break;
+
+		expired = time_after(jiffies, timeout);
+		if (expired) {
+			pr_info("%s: timeout waiting for Tran state status %#x\n",
+				mmc_hostname(host), status);
+			cmd_ret = -ETIMEDOUT;
+			break;
+		}
+	} while (repeat_cmd && R1_CURRENT_STATE(status) != R1_STATE_TRAN);
+
+	/* Wait for data request to complete */
+	if (use_areq)
+		mmc_start_req(host, NULL, &ret);
+	else
+		mmc_wait_for_req_done(test->card->host, mrq);
+
+	/*
+	 * For cap_cmd_during_tfr request, upper layer must send stop if
+	 * required.
+	 */
+	if (mrq->data->stop && (mrq->data->error || !mrq->sbc)) {
+		if (ret)
+			mmc_wait_for_cmd(host, mrq->data->stop, 0);
+		else
+			ret = mmc_wait_for_cmd(host, mrq->data->stop, 0);
+	}
+
+	if (ret)
+		goto out_free;
+
+	if (cmd_ret) {
+		pr_info("%s: Send Status failed: status %#x, error %d\n",
+			mmc_hostname(test->card->host), status, cmd_ret);
+	}
+
+	ret = mmc_test_check_result(test, mrq);
+	if (ret)
+		goto out_free;
+
+	ret = mmc_test_wait_busy(test);
+	if (ret)
+		goto out_free;
+
+	if (repeat_cmd && (t->blocks + 1) << 9 > t->max_tfr)
+		pr_info("%s: %d commands completed during transfer of %u blocks\n",
+			mmc_hostname(test->card->host), count, t->blocks);
+
+	if (cmd_ret)
+		ret = cmd_ret;
+out_free:
+	kfree(rq);
+
+	return ret;
+}
+
+static int __mmc_test_cmds_during_tfr(struct mmc_test_card *test,
+				      unsigned long sz, int use_sbc, int write,
+				      int use_areq)
+{
+	struct mmc_test_area *t = &test->area;
+	int ret;
+
+	if (!(test->card->host->caps & MMC_CAP_CMD_DURING_TFR))
+		return RESULT_UNSUP_HOST;
+
+	ret = mmc_test_area_map(test, sz, 0, 0);
+	if (ret)
+		return ret;
+
+	ret = mmc_test_ongoing_transfer(test, t->dev_addr, use_sbc, 0, write,
+					use_areq);
+	if (ret)
+		return ret;
+
+	return mmc_test_ongoing_transfer(test, t->dev_addr, use_sbc, 1, write,
+					 use_areq);
+}
+
+static int mmc_test_cmds_during_tfr(struct mmc_test_card *test, int use_sbc,
+				    int write, int use_areq)
+{
+	struct mmc_test_area *t = &test->area;
+	unsigned long sz;
+	int ret;
+
+	for (sz = 512; sz <= t->max_tfr; sz += 512) {
+		ret = __mmc_test_cmds_during_tfr(test, sz, use_sbc, write,
+						 use_areq);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
+/*
+ * Commands during read - no Set Block Count (CMD23).
+ */
+static int mmc_test_cmds_during_read(struct mmc_test_card *test)
+{
+	return mmc_test_cmds_during_tfr(test, 0, 0, 0);
+}
+
+/*
+ * Commands during write - no Set Block Count (CMD23).
+ */
+static int mmc_test_cmds_during_write(struct mmc_test_card *test)
+{
+	return mmc_test_cmds_during_tfr(test, 0, 1, 0);
+}
+
+/*
+ * Commands during read - use Set Block Count (CMD23).
+ */
+static int mmc_test_cmds_during_read_cmd23(struct mmc_test_card *test)
+{
+	return mmc_test_cmds_during_tfr(test, 1, 0, 0);
+}
+
+/*
+ * Commands during write - use Set Block Count (CMD23).
+ */
+static int mmc_test_cmds_during_write_cmd23(struct mmc_test_card *test)
+{
+	return mmc_test_cmds_during_tfr(test, 1, 1, 0);
+}
+
+/*
+ * Commands during non-blocking read - use Set Block Count (CMD23).
+ */
+static int mmc_test_cmds_during_read_cmd23_nonblock(struct mmc_test_card *test)
+{
+	return mmc_test_cmds_during_tfr(test, 1, 0, 1);
+}
+
+/*
+ * Commands during non-blocking write - use Set Block Count (CMD23).
+ */
+static int mmc_test_cmds_during_write_cmd23_nonblock(struct mmc_test_card *test)
+{
+	return mmc_test_cmds_during_tfr(test, 1, 1, 1);
+}
+
 static const struct mmc_test_case mmc_test_cases[] = {
 	{
 		.name = "Basic write (no data verification)",
@@ -2605,6 +2871,48 @@ static const struct mmc_test_case mmc_test_cases[] = {
 		.name = "Reset test",
 		.run = mmc_test_reset,
 	},
+
+	{
+		.name = "Commands during read - no Set Block Count (CMD23)",
+		.prepare = mmc_test_area_prepare,
+		.run = mmc_test_cmds_during_read,
+		.cleanup = mmc_test_area_cleanup,
+	},
+
+	{
+		.name = "Commands during write - no Set Block Count (CMD23)",
+		.prepare = mmc_test_area_prepare,
+		.run = mmc_test_cmds_during_write,
+		.cleanup = mmc_test_area_cleanup,
+	},
+
+	{
+		.name = "Commands during read - use Set Block Count (CMD23)",
+		.prepare = mmc_test_area_prepare,
+		.run = mmc_test_cmds_during_read_cmd23,
+		.cleanup = mmc_test_area_cleanup,
+	},
+
+	{
+		.name = "Commands during write - use Set Block Count (CMD23)",
+		.prepare = mmc_test_area_prepare,
+		.run = mmc_test_cmds_during_write_cmd23,
+		.cleanup = mmc_test_area_cleanup,
+	},
+
+	{
+		.name = "Commands during non-blocking read - use Set Block Count (CMD23)",
+		.prepare = mmc_test_area_prepare,
+		.run = mmc_test_cmds_during_read_cmd23_nonblock,
+		.cleanup = mmc_test_area_cleanup,
+	},
+
+	{
+		.name = "Commands during non-blocking write - use Set Block Count (CMD23)",
+		.prepare = mmc_test_area_prepare,
+		.run = mmc_test_cmds_during_write_cmd23_nonblock,
+		.cleanup = mmc_test_area_cleanup,
+	},
 };
 
 static DEFINE_MUTEX(mmc_test_lock);
-- 
1.9.1

[PATCH RFC 03/46] mmc: sdhci: Move busy signal handling into sdhci_finish_cmd()

[Adrian Hunter]

In order to support commands during data transfer, command and data
handling needs to be untangled.

That means sdhci_finish_cmd() must not be called from the data IRQ
handler. It is being called because of busy signal handling, which
is treating the command as not finished until the busy signal is
released.

Instead, move busy signal handling from sdhci_cmd_irq() into
sdhci_finish_cmd(). Then the data IRQ handler does not need to call
sdhci_finish_cmd() and can instead finish the request.

What this means in practice for a command with busy signaling, is that
the command response is read from the host controller when the command
complete interrupt is received, thus freeing up the command circuit for
other commands.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 54 +++++++++++++++++++++++-------------------------
 1 file changed, 26 insertions(+), 28 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 040af1b6b412..fc4301f68a93 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -45,7 +45,6 @@ static unsigned int debug_quirks2;
 
 static void sdhci_finish_data(struct sdhci_host *);
 
-static void sdhci_finish_command(struct sdhci_host *);
 static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode);
 static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable);
 static int sdhci_get_cd(struct mmc_host *mmc);
@@ -1079,6 +1078,28 @@ static void sdhci_finish_command(struct sdhci_host *host)
 		}
 	}
 
+	/*
+	 * The host can send and interrupt when the busy state has
+	 * ended, allowing us to wait without wasting CPU cycles.
+	 * The busy signal uses DAT0 so this is similar to waiting
+	 * for data to complete.
+	 *
+	 * Note: The 1.0 specification is a bit ambiguous about this
+	 *       feature so there might be some problems with older
+	 *       controllers.
+	 */
+	if (host->cmd->flags & MMC_RSP_BUSY) {
+		if (host->cmd->data) {
+			DBG("Cannot wait for busy signal when also doing a data transfer");
+		} else if (!(host->quirks & SDHCI_QUIRK_NO_BUSY_IRQ) &&
+			   !host->busy_handle) {
+			/* Mark that command complete before busy is ended */
+			host->busy_handle = 1;
+			host->cmd = NULL;
+			return;
+		}
+	}
+
 	/* Finished CMD23, now send actual command. */
 	if (host->cmd == host->mrq->sbc) {
 		host->cmd = NULL;
@@ -2289,33 +2310,10 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *mask)
 		return;
 	}
 
-	/*
-	 * The host can send and interrupt when the busy state has
-	 * ended, allowing us to wait without wasting CPU cycles.
-	 * Unfortunately this is overloaded on the "data complete"
-	 * interrupt, so we need to take some care when handling
-	 * it.
-	 *
-	 * Note: The 1.0 specification is a bit ambiguous about this
-	 *       feature so there might be some problems with older
-	 *       controllers.
-	 */
-	if (host->cmd->flags & MMC_RSP_BUSY) {
-		if (host->cmd->data)
-			DBG("Cannot wait for busy signal when also doing a data transfer");
-		else if (!(host->quirks & SDHCI_QUIRK_NO_BUSY_IRQ)
-				&& !host->busy_handle) {
-			/* Mark that command complete before busy is ended */
-			host->busy_handle = 1;
-			return;
-		}
-
-		/* The controller does not support the end-of-busy IRQ,
-		 * fall through and take the SDHCI_INT_RESPONSE */
-	} else if ((host->quirks2 & SDHCI_QUIRK2_STOP_WITH_TC) &&
-		   host->cmd->opcode == MMC_STOP_TRANSMISSION && !host->data) {
+	if ((host->quirks2 & SDHCI_QUIRK2_STOP_WITH_TC) &&
+	    !(host->cmd->flags & MMC_RSP_BUSY) && !host->data &&
+	    host->cmd->opcode == MMC_STOP_TRANSMISSION)
 		*mask &= ~SDHCI_INT_DATA_END;
-	}
 
 	if (intmask & SDHCI_INT_RESPONSE)
 		sdhci_finish_command(host);
@@ -2389,7 +2387,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 				 * sure we do things in the proper order.
 				 */
 				if (host->busy_handle)
-					sdhci_finish_command(host);
+					tasklet_schedule(&host->finish_tasklet);
 				else
 					host->busy_handle = 1;
 				return;
-- 
1.9.1

[PATCH RFC 04/46] mmc: sdhci: Get rid of redundant BUG_ONs

[Adrian Hunter]

BUG is never the right thing for SDHCI to do. Get rid of BUG_ON in cases it
will oops anyway if the pointer is NULL, or if the condition is logically
impossible.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index fc4301f68a93..32d2978c04b9 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -428,8 +428,6 @@ static void sdhci_transfer_pio(struct sdhci_host *host)
 {
 	u32 mask;
 
-	BUG_ON(!host->data);
-
 	if (host->blocks == 0)
 		return;
 
@@ -929,8 +927,6 @@ static void sdhci_finish_data(struct sdhci_host *host)
 {
 	struct mmc_data *data;
 
-	BUG_ON(!host->data);
-
 	data = host->data;
 	host->data = NULL;
 
@@ -1060,8 +1056,6 @@ static void sdhci_finish_command(struct sdhci_host *host)
 {
 	int i;
 
-	BUG_ON(host->cmd == NULL);
-
 	if (host->cmd->flags & MMC_RSP_PRESENT) {
 		if (host->cmd->flags & MMC_RSP_136) {
 			/* CRC is stripped so we need to do some shifting. */
@@ -2273,8 +2267,6 @@ static void sdhci_timeout_timer(unsigned long data)
 
 static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *mask)
 {
-	BUG_ON(intmask == 0);
-
 	if (!host->cmd) {
 		pr_err("%s: Got command interrupt 0x%08x even though no command operation was in progress.\n",
 		       mmc_hostname(host->mmc), (unsigned)intmask);
@@ -2355,7 +2347,6 @@ static void sdhci_adma_show_error(struct sdhci_host *host) { }
 static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 {
 	u32 command;
-	BUG_ON(intmask == 0);
 
 	/* CMD19 generates _only_ Buffer Read Ready interrupt */
 	if (intmask & SDHCI_INT_DATA_AVAIL) {
-- 
1.9.1

[PATCH RFC 05/46] mmc: sdhci: Simplify sdhci_finish_command() by clearing host->cmd at the start

[Adrian Hunter]

sdhci_finish_command() is going to set host->cmd to NULL. Simplify the
code by using a local variable to hold host->cmd and set host->cmd to
NULL at the start.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 32d2978c04b9..5622841458ed 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1054,21 +1054,24 @@ EXPORT_SYMBOL_GPL(sdhci_send_command);
 
 static void sdhci_finish_command(struct sdhci_host *host)
 {
+	struct mmc_command *cmd = host->cmd;
 	int i;
 
-	if (host->cmd->flags & MMC_RSP_PRESENT) {
-		if (host->cmd->flags & MMC_RSP_136) {
+	host->cmd = NULL;
+
+	if (cmd->flags & MMC_RSP_PRESENT) {
+		if (cmd->flags & MMC_RSP_136) {
 			/* CRC is stripped so we need to do some shifting. */
 			for (i = 0;i < 4;i++) {
-				host->cmd->resp[i] = sdhci_readl(host,
+				cmd->resp[i] = sdhci_readl(host,
 					SDHCI_RESPONSE + (3-i)*4) << 8;
 				if (i != 3)
-					host->cmd->resp[i] |=
+					cmd->resp[i] |=
 						sdhci_readb(host,
 						SDHCI_RESPONSE + (3-i)*4-1);
 			}
 		} else {
-			host->cmd->resp[0] = sdhci_readl(host, SDHCI_RESPONSE);
+			cmd->resp[0] = sdhci_readl(host, SDHCI_RESPONSE);
 		}
 	}
 
@@ -1082,21 +1085,19 @@ static void sdhci_finish_command(struct sdhci_host *host)
 	 *       feature so there might be some problems with older
 	 *       controllers.
 	 */
-	if (host->cmd->flags & MMC_RSP_BUSY) {
-		if (host->cmd->data) {
+	if (cmd->flags & MMC_RSP_BUSY) {
+		if (cmd->data) {
 			DBG("Cannot wait for busy signal when also doing a data transfer");
 		} else if (!(host->quirks & SDHCI_QUIRK_NO_BUSY_IRQ) &&
 			   !host->busy_handle) {
 			/* Mark that command complete before busy is ended */
 			host->busy_handle = 1;
-			host->cmd = NULL;
 			return;
 		}
 	}
 
 	/* Finished CMD23, now send actual command. */
-	if (host->cmd == host->mrq->sbc) {
-		host->cmd = NULL;
+	if (cmd == host->mrq->sbc) {
 		sdhci_send_command(host, host->mrq->cmd);
 	} else {
 
@@ -1104,10 +1105,8 @@ static void sdhci_finish_command(struct sdhci_host *host)
 		if (host->data && host->data_early)
 			sdhci_finish_data(host);
 
-		if (!host->cmd->data)
+		if (!cmd->data)
 			tasklet_schedule(&host->finish_tasklet);
-
-		host->cmd = NULL;
 	}
 }
 
-- 
1.9.1

[PATCH RFC 06/46] mmc: sdhci: Record what command is using the data lines

[Adrian Hunter]

In order to support commands during data transfer, there must be a
distinction between the command that is using the command line (and
for which a command interrupt is expected) and the command that is
using the data lines (for which a data interrupt is expected).

There is host->cmd for the command line, but there is only host->data
for the data lines, which is a different structure, does not represent
the command in use, and is anyway NULL in the case of commands that use
the data lines for busy signalling instead of data transfer.

Introduce host->data_cmd to record what command is using the data lines,
and use that instead of host->cmd when referring to the data command.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 17 ++++++++++++++---
 drivers/mmc/host/sdhci.h |  1 +
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 5622841458ed..81b0b52ed4dd 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -929,6 +929,7 @@ static void sdhci_finish_data(struct sdhci_host *host)
 
 	data = host->data;
 	host->data = NULL;
+	host->data_cmd = NULL;
 
 	if ((host->flags & (SDHCI_REQ_USE_DMA | SDHCI_USE_ADMA)) ==
 	    (SDHCI_REQ_USE_DMA | SDHCI_USE_ADMA))
@@ -1014,6 +1015,10 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 
 	host->cmd = cmd;
 	host->busy_handle = 0;
+	if (cmd->data || cmd->flags & MMC_RSP_BUSY) {
+		WARN_ON(host->data_cmd);
+		host->data_cmd = cmd;
+	}
 
 	sdhci_prepare_data(host, cmd);
 
@@ -2218,6 +2223,7 @@ static void sdhci_tasklet_finish(unsigned long param)
 	host->mrq = NULL;
 	host->cmd = NULL;
 	host->data = NULL;
+	host->data_cmd = NULL;
 
 	sdhci_led_deactivate(host);
 
@@ -2359,14 +2365,19 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 	}
 
 	if (!host->data) {
+		struct mmc_command *data_cmd = host->data_cmd;
+
+		if (data_cmd)
+			host->data_cmd = NULL;
+
 		/*
 		 * The "data complete" interrupt is also used to
 		 * indicate that a busy state has ended. See comment
 		 * above in sdhci_cmd_irq().
 		 */
-		if (host->cmd && (host->cmd->flags & MMC_RSP_BUSY)) {
+		if (data_cmd && (data_cmd->flags & MMC_RSP_BUSY)) {
 			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
-				host->cmd->error = -ETIMEDOUT;
+				data_cmd->error = -ETIMEDOUT;
 				tasklet_schedule(&host->finish_tasklet);
 				return;
 			}
@@ -2441,7 +2452,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 		}
 
 		if (intmask & SDHCI_INT_DATA_END) {
-			if (host->cmd) {
+			if (host->cmd == host->data_cmd) {
 				/*
 				 * Data managed to finish before the
 				 * command completed. Make sure we do
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 609f87ca536b..5be3c2471f89 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -463,6 +463,7 @@ struct sdhci_host {
 
 	struct mmc_request *mrq;	/* Current request */
 	struct mmc_command *cmd;	/* Current command */
+	struct mmc_command *data_cmd;	/* Current data command */
 	struct mmc_data *data;	/* Current data request */
 	unsigned int data_early:1;	/* Data finished before cmd */
 	unsigned int busy_handle:1;	/* Handling the order of Busy-end */
-- 
1.9.1

[PATCH RFC 07/46] mmc: sdhci: Get rid of host->busy_handle

[Adrian Hunter]

Now that there is host->data_cmd to record the command for which a data
interrupt is expected, it is possible to determine whether a command with
busy signaling has completed without an extra flag. So host->busy_handle
is not needed. Remove it.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 14 ++++++--------
 drivers/mmc/host/sdhci.h |  1 -
 2 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 81b0b52ed4dd..82e8786098b2 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1014,7 +1014,6 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 	mod_timer(&host->timer, timeout);
 
 	host->cmd = cmd;
-	host->busy_handle = 0;
 	if (cmd->data || cmd->flags & MMC_RSP_BUSY) {
 		WARN_ON(host->data_cmd);
 		host->data_cmd = cmd;
@@ -1094,9 +1093,8 @@ static void sdhci_finish_command(struct sdhci_host *host)
 		if (cmd->data) {
 			DBG("Cannot wait for busy signal when also doing a data transfer");
 		} else if (!(host->quirks & SDHCI_QUIRK_NO_BUSY_IRQ) &&
-			   !host->busy_handle) {
-			/* Mark that command complete before busy is ended */
-			host->busy_handle = 1;
+			   cmd == host->data_cmd) {
+			/* Command complete before busy is ended */
 			return;
 		}
 	}
@@ -2387,10 +2385,10 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 				 * before the command completed, so make
 				 * sure we do things in the proper order.
 				 */
-				if (host->busy_handle)
-					tasklet_schedule(&host->finish_tasklet);
-				else
-					host->busy_handle = 1;
+				if (host->cmd == data_cmd)
+					return;
+
+				tasklet_schedule(&host->finish_tasklet);
 				return;
 			}
 		}
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 5be3c2471f89..d649dfd2f4d2 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -466,7 +466,6 @@ struct sdhci_host {
 	struct mmc_command *data_cmd;	/* Current data command */
 	struct mmc_data *data;	/* Current data request */
 	unsigned int data_early:1;	/* Data finished before cmd */
-	unsigned int busy_handle:1;	/* Handling the order of Busy-end */
 
 	struct sg_mapping_iter sg_miter;	/* SG state for PIO */
 	unsigned int blocks;	/* remaining PIO blocks */
-- 
1.9.1

[PATCH RFC 08/46] mmc: sdhci: Reduce the use of host->mrq

[Adrian Hunter]

In order to support commands during data transfer, there will have to be up
to two active requests (mrqs) at a time, instead of just one. That means
host->mrq will not be able to be used.

In several places, host->mrq is used when instead the mrq can be determined
from the cmd or data pointers. Reduce the use of host->mrq by doing that.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 82e8786098b2..02a8522dc74e 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -906,12 +906,12 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
 		 * If we are sending CMD23, CMD12 never gets sent
 		 * on successful completion (so no Auto-CMD12).
 		 */
-		if (!host->mrq->sbc && (host->flags & SDHCI_AUTO_CMD12) &&
+		if (!cmd->mrq->sbc && (host->flags & SDHCI_AUTO_CMD12) &&
 		    (cmd->opcode != SD_IO_RW_EXTENDED))
 			mode |= SDHCI_TRNS_AUTO_CMD12;
-		else if (host->mrq->sbc && (host->flags & SDHCI_AUTO_CMD23)) {
+		else if (cmd->mrq->sbc && (host->flags & SDHCI_AUTO_CMD23)) {
 			mode |= SDHCI_TRNS_AUTO_CMD23;
-			sdhci_writel(host, host->mrq->sbc->arg, SDHCI_ARGUMENT2);
+			sdhci_writel(host, cmd->mrq->sbc->arg, SDHCI_ARGUMENT2);
 		}
 	}
 
@@ -954,7 +954,7 @@ static void sdhci_finish_data(struct sdhci_host *host)
 	 */
 	if (data->stop &&
 	    (data->error ||
-	     !host->mrq->sbc)) {
+	     !data->mrq->sbc)) {
 
 		/*
 		 * The controller needs a reset of internal state machines
@@ -990,7 +990,7 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 
 	/* We shouldn't wait for data inihibit for stop commands, even
 	   though they might use busy signaling */
-	if (host->mrq->data && (cmd == host->mrq->data->stop))
+	if (cmd->mrq->data && (cmd == cmd->mrq->data->stop))
 		mask &= ~SDHCI_DATA_INHIBIT;
 
 	while (sdhci_readl(host, SDHCI_PRESENT_STATE) & mask) {
@@ -1100,8 +1100,8 @@ static void sdhci_finish_command(struct sdhci_host *host)
 	}
 
 	/* Finished CMD23, now send actual command. */
-	if (cmd == host->mrq->sbc) {
-		sdhci_send_command(host, host->mrq->cmd);
+	if (cmd == cmd->mrq->sbc) {
+		sdhci_send_command(host, cmd->mrq->cmd);
 	} else {
 
 		/* Processed actual command. */
@@ -1408,7 +1408,7 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 	host->mrq = mrq;
 
 	if (!present || host->flags & SDHCI_DEVICE_DEAD) {
-		host->mrq->cmd->error = -ENOMEDIUM;
+		mrq->cmd->error = -ENOMEDIUM;
 		tasklet_schedule(&host->finish_tasklet);
 	} else {
 		if (mrq->sbc && !(host->flags & SDHCI_AUTO_CMD23))
-- 
1.9.1

[PATCH RFC 09/46] mmc: sdhci: Move host->data warning

[Adrian Hunter]

In order to support commands during data transfer, it will be possible
that host->data is not NULL when preparing a new request. Move a warning
that assumes otherwise.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 02a8522dc74e..1edb827bbab2 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -744,14 +744,14 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
 	u8 ctrl;
 	struct mmc_data *data = cmd->data;
 
-	WARN_ON(host->data);
-
 	if (data || (cmd->flags & MMC_RSP_BUSY))
 		sdhci_set_timeout(host, cmd);
 
 	if (!data)
 		return;
 
+	WARN_ON(host->data);
+
 	/* Sanity checks */
 	BUG_ON(data->blksz * data->blocks > 524288);
 	BUG_ON(data->blksz > host->mmc->max_blk_size);
-- 
1.9.1

[PATCH RFC 10/46] mmc: sdhci: Factor out sdhci_finish_mrq()

[Adrian Hunter]

In order to support commands during data transfer, there will have to be up
to two active requests (mrqs) at a time, instead of just one. That means
the driver must identify which one to finish. Prepare for that by factoring
out sdhci_finish_mrq().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 1edb827bbab2..e6eec10b46de 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -923,6 +923,11 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
 	sdhci_writew(host, mode, SDHCI_TRANSFER_MODE);
 }
 
+static void sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
+{
+	tasklet_schedule(&host->finish_tasklet);
+}
+
 static void sdhci_finish_data(struct sdhci_host *host)
 {
 	struct mmc_data *data;
@@ -966,8 +971,9 @@ static void sdhci_finish_data(struct sdhci_host *host)
 		}
 
 		sdhci_send_command(host, data->stop);
-	} else
-		tasklet_schedule(&host->finish_tasklet);
+	} else {
+		sdhci_finish_mrq(host, data->mrq);
+	}
 }
 
 void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
@@ -999,7 +1005,7 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 			       mmc_hostname(host->mmc));
 			sdhci_dumpregs(host);
 			cmd->error = -EIO;
-			tasklet_schedule(&host->finish_tasklet);
+			sdhci_finish_mrq(host, cmd->mrq);
 			return;
 		}
 		timeout--;
@@ -1029,7 +1035,7 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 		pr_err("%s: Unsupported response type!\n",
 			mmc_hostname(host->mmc));
 		cmd->error = -EINVAL;
-		tasklet_schedule(&host->finish_tasklet);
+		sdhci_finish_mrq(host, cmd->mrq);
 		return;
 	}
 
@@ -1109,7 +1115,7 @@ static void sdhci_finish_command(struct sdhci_host *host)
 			sdhci_finish_data(host);
 
 		if (!cmd->data)
-			tasklet_schedule(&host->finish_tasklet);
+			sdhci_finish_mrq(host, cmd->mrq);
 	}
 }
 
@@ -1409,7 +1415,7 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 
 	if (!present || host->flags & SDHCI_DEVICE_DEAD) {
 		mrq->cmd->error = -ENOMEDIUM;
-		tasklet_schedule(&host->finish_tasklet);
+		sdhci_finish_mrq(host, mrq);
 	} else {
 		if (mrq->sbc && !(host->flags & SDHCI_AUTO_CMD23))
 			sdhci_send_command(host, mrq->sbc);
@@ -2128,7 +2134,7 @@ static void sdhci_card_event(struct mmc_host *mmc)
 		sdhci_do_reset(host, SDHCI_RESET_DATA);
 
 		host->mrq->cmd->error = -ENOMEDIUM;
-		tasklet_schedule(&host->finish_tasklet);
+		sdhci_finish_mrq(host, host->mrq);
 	}
 
 	spin_unlock_irqrestore(&host->lock, flags);
@@ -2254,7 +2260,7 @@ static void sdhci_timeout_timer(unsigned long data)
 			else
 				host->mrq->cmd->error = -ETIMEDOUT;
 
-			tasklet_schedule(&host->finish_tasklet);
+			sdhci_finish_mrq(host, host->mrq);
 		}
 	}
 
@@ -2301,7 +2307,7 @@ static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *mask)
 			return;
 		}
 
-		tasklet_schedule(&host->finish_tasklet);
+		sdhci_finish_mrq(host, host->cmd->mrq);
 		return;
 	}
 
@@ -2376,7 +2382,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 		if (data_cmd && (data_cmd->flags & MMC_RSP_BUSY)) {
 			if (intmask & SDHCI_INT_DATA_TIMEOUT) {
 				data_cmd->error = -ETIMEDOUT;
-				tasklet_schedule(&host->finish_tasklet);
+				sdhci_finish_mrq(host, data_cmd->mrq);
 				return;
 			}
 			if (intmask & SDHCI_INT_DATA_END) {
@@ -2388,7 +2394,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 				if (host->cmd == data_cmd)
 					return;
 
-				tasklet_schedule(&host->finish_tasklet);
+				sdhci_finish_mrq(host, data_cmd->mrq);
 				return;
 			}
 		}
@@ -3394,7 +3400,7 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
 				" transfer!\n", mmc_hostname(mmc));
 
 			host->mrq->cmd->error = -ENOMEDIUM;
-			tasklet_schedule(&host->finish_tasklet);
+			sdhci_finish_mrq(host, host->mrq);
 		}
 
 		spin_unlock_irqrestore(&host->lock, flags);
-- 
1.9.1

[PATCH RFC 11/46] mmc: sdhci: Factor out sdhci_needs_reset()

[Adrian Hunter]

Factor out sdhci_needs_reset() so it can be reused.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index e6eec10b46de..f75c226de7ff 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -923,6 +923,16 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
 	sdhci_writew(host, mode, SDHCI_TRANSFER_MODE);
 }
 
+static bool sdhci_needs_reset(struct sdhci_host *host, struct mmc_request *mrq)
+{
+	return (!(host->flags & SDHCI_DEVICE_DEAD) &&
+		((mrq->cmd && mrq->cmd->error) ||
+		 (mrq->sbc && mrq->sbc->error) ||
+		 (mrq->data && ((mrq->data->error && !mrq->data->stop) ||
+				(mrq->data->stop && mrq->data->stop->error))) ||
+		 (host->quirks & SDHCI_QUIRK_RESET_AFTER_REQUEST)));
+}
+
 static void sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
 {
 	tasklet_schedule(&host->finish_tasklet);
@@ -2206,13 +2216,7 @@ static void sdhci_tasklet_finish(unsigned long param)
 	 * The controller needs a reset of internal state machines
 	 * upon error conditions.
 	 */
-	if (!(host->flags & SDHCI_DEVICE_DEAD) &&
-	    ((mrq->cmd && mrq->cmd->error) ||
-	     (mrq->sbc && mrq->sbc->error) ||
-	     (mrq->data && ((mrq->data->error && !mrq->data->stop) ||
-			    (mrq->data->stop && mrq->data->stop->error))) ||
-	     (host->quirks & SDHCI_QUIRK_RESET_AFTER_REQUEST))) {
-
+	if (sdhci_needs_reset(host, mrq)) {
 		/* Some controllers need this kick or reset won't work here */
 		if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)
 			/* This is to force an update */
-- 
1.9.1

[PATCH RFC 12/46] mmc: sdhci: Track whether a reset is pending

[Adrian Hunter]

SDHCI recovers from errors by resetting the cmd and data circuits. Until
that is done, there very well might be more interrupts, so ignore them in
that case.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 20 ++++++++++++++++++++
 drivers/mmc/host/sdhci.h |  1 +
 2 files changed, 21 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index f75c226de7ff..a1afcd9dd228 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -935,6 +935,9 @@ static bool sdhci_needs_reset(struct sdhci_host *host, struct mmc_request *mrq)
 
 static void sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
 {
+	if (sdhci_needs_reset(host, mrq))
+		host->pending_reset = true;
+
 	tasklet_schedule(&host->finish_tasklet);
 }
 
@@ -2226,6 +2229,8 @@ static void sdhci_tasklet_finish(unsigned long param)
 		   controllers do not like that. */
 		sdhci_do_reset(host, SDHCI_RESET_CMD);
 		sdhci_do_reset(host, SDHCI_RESET_DATA);
+
+		host->pending_reset = false;
 	}
 
 	host->mrq = NULL;
@@ -2281,6 +2286,13 @@ static void sdhci_timeout_timer(unsigned long data)
 static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask, u32 *mask)
 {
 	if (!host->cmd) {
+		/*
+		 * SDHCI recovers from errors by resetting the cmd and data
+		 * circuits.  Until that is done, there very well might be more
+		 * interrupts, so ignore them in that case.
+		 */
+		if (host->pending_reset)
+			return;
 		pr_err("%s: Got command interrupt 0x%08x even though no command operation was in progress.\n",
 		       mmc_hostname(host->mmc), (unsigned)intmask);
 		sdhci_dumpregs(host);
@@ -2403,6 +2415,14 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 			}
 		}
 
+		/*
+		 * SDHCI recovers from errors by resetting the cmd and data
+		 * circuits. Until that is done, there very well might be more
+		 * interrupts, so ignore them in that case.
+		 */
+		if (host->pending_reset)
+			return;
+
 		pr_err("%s: Got data interrupt 0x%08x even though no data operation was in progress.\n",
 		       mmc_hostname(host->mmc), (unsigned)intmask);
 		sdhci_dumpregs(host);
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index d649dfd2f4d2..331a72b417ef 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -460,6 +460,7 @@ struct sdhci_host {
 	bool runtime_suspended;	/* Host is runtime suspended */
 	bool bus_on;		/* Bus power prevents runtime suspend */
 	bool preset_enabled;	/* Preset is enabled */
+	bool pending_reset;	/* Cmd/data reset is pending */
 
 	struct mmc_request *mrq;	/* Current request */
 	struct mmc_command *cmd;	/* Current command */
-- 
1.9.1

[PATCH RFC 13/46] mmc: sdhci: Clear pointers when a request finishes

[Adrian Hunter]

Several pointers are used to identify when interrupts are expected. Namely,
host->cmd, host->data_cmd and host->data. Ensure those are cleared when
a request finishes. That tidies the case when a request is errored out
before normal processing has completed, ensuring any interrupts that occur
subsequently are not acted upon.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a1afcd9dd228..4361c3829106 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -935,6 +935,15 @@ static bool sdhci_needs_reset(struct sdhci_host *host, struct mmc_request *mrq)
 
 static void sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
 {
+	if (host->cmd && host->cmd->mrq == mrq)
+		host->cmd = NULL;
+
+	if (host->data_cmd && host->data_cmd->mrq == mrq)
+		host->data_cmd = NULL;
+
+	if (host->data && host->data->mrq == mrq)
+		host->data = NULL;
+
 	if (sdhci_needs_reset(host, mrq))
 		host->pending_reset = true;
 
@@ -2234,9 +2243,6 @@ static void sdhci_tasklet_finish(unsigned long param)
 	}
 
 	host->mrq = NULL;
-	host->cmd = NULL;
-	host->data = NULL;
-	host->data_cmd = NULL;
 
 	sdhci_led_deactivate(host);
 
-- 
1.9.1

[PATCH RFC 14/46] mmc: sdhci: Ensure all requests get errored out

[Adrian Hunter]

In order to support commands during data transfer, there will have to be up
to two active requests (mrqs) at a time, instead of just one. That means
ensuring that all requests get errored out in the cases of card or driver
removal.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 4361c3829106..e124dc632cac 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2131,6 +2131,24 @@ static void sdhci_pre_req(struct mmc_host *mmc, struct mmc_request *mrq,
 		sdhci_pre_dma_transfer(host, mrq->data, COOKIE_PRE_MAPPED);
 }
 
+static inline bool sdhci_has_requests(struct sdhci_host *host)
+{
+	return host->cmd || host->data_cmd;
+}
+
+static void sdhci_error_out_mrqs(struct sdhci_host *host, int err)
+{
+	if (host->data_cmd) {
+		host->data_cmd->error = err;
+		sdhci_finish_mrq(host, host->data_cmd->mrq);
+	}
+
+	if (host->cmd) {
+		host->cmd->error = err;
+		sdhci_finish_mrq(host, host->cmd->mrq);
+	}
+}
+
 static void sdhci_card_event(struct mmc_host *mmc)
 {
 	struct sdhci_host *host = mmc_priv(mmc);
@@ -2145,8 +2163,8 @@ static void sdhci_card_event(struct mmc_host *mmc)
 
 	spin_lock_irqsave(&host->lock, flags);
 
-	/* Check host->mrq first in case we are runtime suspended */
-	if (host->mrq && !present) {
+	/* Check sdhci_has_requests() first in case we are runtime suspended */
+	if (sdhci_has_requests(host) && !present) {
 		pr_err("%s: Card removed during transfer!\n",
 			mmc_hostname(host->mmc));
 		pr_err("%s: Resetting controller.\n",
@@ -2155,8 +2173,7 @@ static void sdhci_card_event(struct mmc_host *mmc)
 		sdhci_do_reset(host, SDHCI_RESET_CMD);
 		sdhci_do_reset(host, SDHCI_RESET_DATA);
 
-		host->mrq->cmd->error = -ENOMEDIUM;
-		sdhci_finish_mrq(host, host->mrq);
+		sdhci_error_out_mrqs(host, -ENOMEDIUM);
 	}
 
 	spin_unlock_irqrestore(&host->lock, flags);
@@ -3425,12 +3442,10 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
 
 		host->flags |= SDHCI_DEVICE_DEAD;
 
-		if (host->mrq) {
+		if (sdhci_has_requests(host)) {
 			pr_err("%s: Controller removed during "
 				" transfer!\n", mmc_hostname(mmc));
-
-			host->mrq->cmd->error = -ENOMEDIUM;
-			sdhci_finish_mrq(host, host->mrq);
+			sdhci_error_out_mrqs(host, -ENOMEDIUM);
 		}
 
 		spin_unlock_irqrestore(&host->lock, flags);
-- 
1.9.1

[PATCH RFC 15/46] mmc: sdhci: Factor out sdhci_data_line_cmd()

[Adrian Hunter]

Factor out sdhci_data_line_cmd() to improve readability and because it is
used in multiple places.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index e124dc632cac..90180d0d752c 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -111,6 +111,11 @@ static void sdhci_dumpregs(struct sdhci_host *host)
  *                                                                           *
 \*****************************************************************************/
 
+static inline bool sdhci_data_line_cmd(struct mmc_command *cmd)
+{
+	return cmd->data || cmd->flags & MMC_RSP_BUSY;
+}
+
 static void sdhci_set_card_detection(struct sdhci_host *host, bool enable)
 {
 	u32 present;
@@ -744,7 +749,7 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
 	u8 ctrl;
 	struct mmc_data *data = cmd->data;
 
-	if (data || (cmd->flags & MMC_RSP_BUSY))
+	if (sdhci_data_line_cmd(cmd))
 		sdhci_set_timeout(host, cmd);
 
 	if (!data)
@@ -1013,7 +1018,7 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 	timeout = 10;
 
 	mask = SDHCI_CMD_INHIBIT;
-	if ((cmd->data != NULL) || (cmd->flags & MMC_RSP_BUSY))
+	if (sdhci_data_line_cmd(cmd))
 		mask |= SDHCI_DATA_INHIBIT;
 
 	/* We shouldn't wait for data inihibit for stop commands, even
@@ -1042,7 +1047,7 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 	mod_timer(&host->timer, timeout);
 
 	host->cmd = cmd;
-	if (cmd->data || cmd->flags & MMC_RSP_BUSY) {
+	if (sdhci_data_line_cmd(cmd)) {
 		WARN_ON(host->data_cmd);
 		host->data_cmd = cmd;
 	}
-- 
1.9.1

[PATCH RFC 16/46] mmc: sdhci: Separate timer timeout for command and data requests

[Adrian Hunter]

In order to support commands during data transfer, there will have to be up
to two active requests (mrqs) at a time, instead of just one. Provide two
timers instead of just one. One of the timers is for requests that do not
use the data lines, and the other one is for requests that do.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 62 ++++++++++++++++++++++++++++++++++++++++--------
 drivers/mmc/host/sdhci.h |  1 +
 2 files changed, 53 insertions(+), 10 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 90180d0d752c..f04df6f42f35 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1003,6 +1003,23 @@ static void sdhci_finish_data(struct sdhci_host *host)
 	}
 }
 
+static void sdhci_mod_timer(struct sdhci_host *host, struct mmc_request *mrq,
+			    unsigned long timeout)
+{
+	if (sdhci_data_line_cmd(mrq->cmd))
+		mod_timer(&host->data_timer, timeout);
+	else
+		mod_timer(&host->timer, timeout);
+}
+
+static void sdhci_del_timer(struct sdhci_host *host, struct mmc_request *mrq)
+{
+	if (sdhci_data_line_cmd(mrq->cmd))
+		del_timer(&host->data_timer);
+	else
+		del_timer(&host->timer);
+}
+
 void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 {
 	int flags;
@@ -1044,7 +1061,7 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 		timeout += DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ;
 	else
 		timeout += 10 * HZ;
-	mod_timer(&host->timer, timeout);
+	sdhci_mod_timer(host, cmd->mrq, timeout);
 
 	host->cmd = cmd;
 	if (sdhci_data_line_cmd(cmd)) {
@@ -2226,10 +2243,10 @@ static void sdhci_tasklet_finish(unsigned long param)
 		return;
 	}
 
-	del_timer(&host->timer);
-
 	mrq = host->mrq;
 
+	sdhci_del_timer(host, mrq);
+
 	/*
 	 * Always unmap the data buffers if they were mapped by
 	 * sdhci_prepare_data() whenever we finish with a request.
@@ -2283,7 +2300,30 @@ static void sdhci_timeout_timer(unsigned long data)
 
 	spin_lock_irqsave(&host->lock, flags);
 
-	if (host->mrq) {
+	if (host->cmd && !sdhci_data_line_cmd(host->cmd)) {
+		pr_err("%s: Timeout waiting for hardware cmd interrupt.\n",
+		       mmc_hostname(host->mmc));
+		sdhci_dumpregs(host);
+
+		host->cmd->error = -ETIMEDOUT;
+		sdhci_finish_mrq(host, host->cmd->mrq);
+	}
+
+	mmiowb();
+	spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void sdhci_timeout_data_timer(unsigned long data)
+{
+	struct sdhci_host *host;
+	unsigned long flags;
+
+	host = (struct sdhci_host *)data;
+
+	spin_lock_irqsave(&host->lock, flags);
+
+	if (host->data || host->data_cmd ||
+	    (host->cmd && sdhci_data_line_cmd(host->cmd))) {
 		pr_err("%s: Timeout waiting for hardware interrupt.\n",
 		       mmc_hostname(host->mmc));
 		sdhci_dumpregs(host);
@@ -2291,13 +2331,12 @@ static void sdhci_timeout_timer(unsigned long data)
 		if (host->data) {
 			host->data->error = -ETIMEDOUT;
 			sdhci_finish_data(host);
+		} else if (host->data_cmd) {
+			host->data_cmd->error = -ETIMEDOUT;
+			sdhci_finish_mrq(host, host->data_cmd->mrq);
 		} else {
-			if (host->cmd)
-				host->cmd->error = -ETIMEDOUT;
-			else
-				host->mrq->cmd->error = -ETIMEDOUT;
-
-			sdhci_finish_mrq(host, host->mrq);
+			host->cmd->error = -ETIMEDOUT;
+			sdhci_finish_mrq(host, host->cmd->mrq);
 		}
 	}
 
@@ -3372,6 +3411,8 @@ int sdhci_add_host(struct sdhci_host *host)
 		sdhci_tasklet_finish, (unsigned long)host);
 
 	setup_timer(&host->timer, sdhci_timeout_timer, (unsigned long)host);
+	setup_timer(&host->data_timer, sdhci_timeout_data_timer,
+		    (unsigned long)host);
 
 	init_waitqueue_head(&host->buf_ready_int);
 
@@ -3470,6 +3511,7 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
 	free_irq(host->irq, host);
 
 	del_timer_sync(&host->timer);
+	del_timer_sync(&host->data_timer);
 
 	tasklet_kill(&host->finish_tasklet);
 
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 331a72b417ef..10f835f785f7 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -487,6 +487,7 @@ struct sdhci_host {
 	struct tasklet_struct finish_tasklet;	/* Tasklet structures */
 
 	struct timer_list timer;	/* Timer for timeouts */
+	struct timer_list data_timer;	/* Timer for data timeouts */
 
 	u32 caps;		/* Alternative CAPABILITY_0 */
 	u32 caps1;		/* Alternative CAPABILITY_1 */
-- 
1.9.1

[PATCH RFC 17/46] mmc: sdhci: Allow for finishing multiple requests

[Adrian Hunter]

In order to support commands during data transfer, there will have to be up
to two active requests (mrqs) at a time, instead of just one. That means
recording which request is finished.  Doing that obsoletes host->mrq which
is therefore removed.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 71 +++++++++++++++++++++++++++++++++---------------
 drivers/mmc/host/sdhci.h |  5 +++-
 2 files changed, 53 insertions(+), 23 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index f04df6f42f35..fa527a89ee4c 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -938,6 +938,29 @@ static bool sdhci_needs_reset(struct sdhci_host *host, struct mmc_request *mrq)
 		 (host->quirks & SDHCI_QUIRK_RESET_AFTER_REQUEST)));
 }
 
+static void __sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
+{
+	int i;
+
+	for (i = 0; i < SDHCI_MAX_MRQS; i++) {
+		if (host->mrqs_done[i] == mrq) {
+			WARN_ON(1);
+			return;
+		}
+	}
+
+	for (i = 0; i < SDHCI_MAX_MRQS; i++) {
+		if (!host->mrqs_done[i]) {
+			host->mrqs_done[i] = mrq;
+			break;
+		}
+	}
+
+	WARN_ON(i >= SDHCI_MAX_MRQS);
+
+	tasklet_schedule(&host->finish_tasklet);
+}
+
 static void sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
 {
 	if (host->cmd && host->cmd->mrq == mrq)
@@ -952,7 +975,7 @@ static void sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
 	if (sdhci_needs_reset(host, mrq))
 		host->pending_reset = true;
 
-	tasklet_schedule(&host->finish_tasklet);
+	__sdhci_finish_mrq(host, mrq);
 }
 
 static void sdhci_finish_data(struct sdhci_host *host)
@@ -1440,8 +1463,6 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 
 	spin_lock_irqsave(&host->lock, flags);
 
-	WARN_ON(host->mrq != NULL);
-
 	sdhci_led_activate(host);
 
 	/*
@@ -1455,8 +1476,6 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 		}
 	}
 
-	host->mrq = mrq;
-
 	if (!present || host->flags & SDHCI_DEVICE_DEAD) {
 		mrq->cmd->error = -ENOMEDIUM;
 		sdhci_finish_mrq(host, mrq);
@@ -1987,13 +2006,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
 		cmd.retries = 0;
 		cmd.data = NULL;
+		cmd.mrq = &mrq;
 		cmd.error = 0;
 
 		if (tuning_loop_counter-- == 0)
 			break;
 
 		mrq.cmd = &cmd;
-		host->mrq = &mrq;
 
 		/*
 		 * In response to CMD19, the card sends 64 bytes of tuning
@@ -2023,7 +2042,6 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		sdhci_send_command(host, &cmd);
 
 		host->cmd = NULL;
-		host->mrq = NULL;
 
 		spin_unlock_irqrestore(&host->lock, flags);
 		/* Wait for Buffer Read Ready interrupt */
@@ -2224,26 +2242,26 @@ static const struct mmc_host_ops sdhci_ops = {
  *                                                                           *
 \*****************************************************************************/
 
-static void sdhci_tasklet_finish(unsigned long param)
+static bool sdhci_request_done(struct sdhci_host *host)
 {
-	struct sdhci_host *host;
 	unsigned long flags;
 	struct mmc_request *mrq;
-
-	host = (struct sdhci_host*)param;
+	int i;
 
 	spin_lock_irqsave(&host->lock, flags);
 
-        /*
-         * If this tasklet gets rescheduled while running, it will
-         * be run again afterwards but without any active request.
-         */
-	if (!host->mrq) {
-		spin_unlock_irqrestore(&host->lock, flags);
-		return;
+	for (i = 0; i < SDHCI_MAX_MRQS; i++) {
+		mrq = host->mrqs_done[i];
+		if (mrq) {
+			host->mrqs_done[i] = NULL;
+			break;
+		}
 	}
 
-	mrq = host->mrq;
+	if (!mrq) {
+		spin_unlock_irqrestore(&host->lock, flags);
+		return true;
+	}
 
 	sdhci_del_timer(host, mrq);
 
@@ -2281,14 +2299,23 @@ static void sdhci_tasklet_finish(unsigned long param)
 		host->pending_reset = false;
 	}
 
-	host->mrq = NULL;
-
-	sdhci_led_deactivate(host);
+	if (!sdhci_has_requests(host))
+		sdhci_led_deactivate(host);
 
 	mmiowb();
 	spin_unlock_irqrestore(&host->lock, flags);
 
 	mmc_request_done(host->mmc, mrq);
+
+	return false;
+}
+
+static void sdhci_tasklet_finish(unsigned long param)
+{
+	struct sdhci_host *host = (struct sdhci_host *)param;
+
+	while (!sdhci_request_done(host))
+		;
 }
 
 static void sdhci_timeout_timer(unsigned long data)
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 10f835f785f7..7c1f3cf4c459 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -314,6 +314,9 @@ struct sdhci_adma2_64_desc {
  */
 #define SDHCI_MAX_SEGS		128
 
+/* Allow for a a command request and a data request at the same time */
+#define SDHCI_MAX_MRQS		2
+
 enum sdhci_cookie {
 	COOKIE_UNMAPPED,
 	COOKIE_PRE_MAPPED,	/* mapped by sdhci_pre_req() */
@@ -462,7 +465,7 @@ struct sdhci_host {
 	bool preset_enabled;	/* Preset is enabled */
 	bool pending_reset;	/* Cmd/data reset is pending */
 
-	struct mmc_request *mrq;	/* Current request */
+	struct mmc_request *mrqs_done[SDHCI_MAX_MRQS];	/* Requests done */
 	struct mmc_command *cmd;	/* Current command */
 	struct mmc_command *data_cmd;	/* Current data command */
 	struct mmc_data *data;	/* Current data request */
-- 
1.9.1

[PATCH RFC 18/46] mmc: sdhci: Factor out sdhci_auto_cmd12()

[Adrian Hunter]

Factor out sdhci_auto_cmd12() so that there is a single place that controls
whether auto-CMD12 is used.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index fa527a89ee4c..690bffa24e93 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -881,6 +881,12 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
 	sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
 }
 
+static inline bool sdhci_auto_cmd12(struct sdhci_host *host,
+				    struct mmc_request *mrq)
+{
+	return !mrq->sbc && (host->flags & SDHCI_AUTO_CMD12);
+}
+
 static void sdhci_set_transfer_mode(struct sdhci_host *host,
 	struct mmc_command *cmd)
 {
@@ -911,7 +917,7 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
 		 * If we are sending CMD23, CMD12 never gets sent
 		 * on successful completion (so no Auto-CMD12).
 		 */
-		if (!cmd->mrq->sbc && (host->flags & SDHCI_AUTO_CMD12) &&
+		if (sdhci_auto_cmd12(host, cmd->mrq) &&
 		    (cmd->opcode != SD_IO_RW_EXTENDED))
 			mode |= SDHCI_TRNS_AUTO_CMD12;
 		else if (cmd->mrq->sbc && (host->flags & SDHCI_AUTO_CMD23)) {
@@ -1469,7 +1475,7 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 	 * Ensure we don't send the STOP for non-SET_BLOCK_COUNTED
 	 * requests if Auto-CMD12 is enabled.
 	 */
-	if (!mrq->sbc && (host->flags & SDHCI_AUTO_CMD12)) {
+	if (sdhci_auto_cmd12(host, mrq)) {
 		if (mrq->stop) {
 			mrq->data->stop = NULL;
 			mrq->stop = NULL;
-- 
1.9.1

[PATCH RFC 19/46] mmc: sdhci: Do not reset cmd or data circuits that are in use

[Adrian Hunter]

In order to support commands during data transfer, it will be possible to
need to reset the command circuit while the data circuit is in use, and
vice versa. It is now easy to determine whether the command or data circuit
is in use, and so just skip the corresponding reset if it is.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 690bffa24e93..e9eb71861764 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1022,7 +1022,8 @@ static void sdhci_finish_data(struct sdhci_host *host)
 		 * upon error conditions.
 		 */
 		if (data->error) {
-			sdhci_do_reset(host, SDHCI_RESET_CMD);
+			if (!host->cmd)
+				sdhci_do_reset(host, SDHCI_RESET_CMD);
 			sdhci_do_reset(host, SDHCI_RESET_DATA);
 		}
 
@@ -2299,8 +2300,10 @@ static bool sdhci_request_done(struct sdhci_host *host)
 
 		/* Spec says we should do both at the same time, but Ricoh
 		   controllers do not like that. */
-		sdhci_do_reset(host, SDHCI_RESET_CMD);
-		sdhci_do_reset(host, SDHCI_RESET_DATA);
+		if (!host->cmd)
+			sdhci_do_reset(host, SDHCI_RESET_CMD);
+		if (!host->data_cmd)
+			sdhci_do_reset(host, SDHCI_RESET_DATA);
 
 		host->pending_reset = false;
 	}
-- 
1.9.1

[PATCH RFC 20/46] mmc: sdhci: Support cap_cmd_during_tfr requests

[Adrian Hunter]

Now SDHCI supports commands during transfer, enable support for the core
API.

There are 3 small changes needed:

First, auto-CMD12 cannot be used with a cap_cmd_during_tfr request because
the host controller cannot expect the command line to be available.

Secondly, a cap_cmd_during_tfr request must not send a stop command, again
because the host controller cannot expect the command line to be available.

Thirdly, when a cap_cmd_during_tfr command completes, use
mmc_command_complete() to notify the upper layers that the command line is
now available for further commands.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index e9eb71861764..aa2aa16386b9 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -884,7 +884,8 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
 static inline bool sdhci_auto_cmd12(struct sdhci_host *host,
 				    struct mmc_request *mrq)
 {
-	return !mrq->sbc && (host->flags & SDHCI_AUTO_CMD12);
+	return !mrq->sbc && (host->flags & SDHCI_AUTO_CMD12) &&
+	       !mrq->cap_cmd_during_tfr;
 }
 
 static void sdhci_set_transfer_mode(struct sdhci_host *host,
@@ -1027,7 +1028,15 @@ static void sdhci_finish_data(struct sdhci_host *host)
 			sdhci_do_reset(host, SDHCI_RESET_DATA);
 		}
 
-		sdhci_send_command(host, data->stop);
+		/*
+		 * 'cap_cmd_during_tfr' request must not use the command line
+		 * after mmc_command_done() has been called. It is upper layer's
+		 * responsibility to send the stop command if required.
+		 */
+		if (data->mrq->cap_cmd_during_tfr)
+			sdhci_finish_mrq(host, data->mrq);
+		else
+			sdhci_send_command(host, data->stop);
 	} else {
 		sdhci_finish_mrq(host, data->mrq);
 	}
@@ -1159,6 +1168,9 @@ static void sdhci_finish_command(struct sdhci_host *host)
 		}
 	}
 
+	if (cmd->mrq->cap_cmd_during_tfr && cmd == cmd->mrq->cmd)
+		mmc_command_done(host->mmc, cmd->mrq);
+
 	/*
 	 * The host can send and interrupt when the busy state has
 	 * ended, allowing us to wait without wasting CPU cycles.
-- 
1.9.1

[PATCH RFC 21/46] mmc: sdhci-pci: Set MMC_CAP_CMD_DURING_TFR for Intel eMMC controllers

[Adrian Hunter]

Set MMC_CAP_CMD_DURING_TFR for Intel BYT and related eMMC host controllers.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci-pci-core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index a4dbf7421edc..88f3958f014d 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -356,6 +356,7 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot)
 {
 	slot->host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE |
 				 MMC_CAP_HW_RESET | MMC_CAP_1_8V_DDR |
+				 MMC_CAP_CMD_DURING_TFR |
 				 MMC_CAP_WAIT_WHILE_BUSY;
 	slot->host->mmc->caps2 |= MMC_CAP2_HC_ERASE_SZ;
 	slot->hw_reset = sdhci_pci_int_hw_reset;
-- 
1.9.1

[PATCH RFC 22/46] mmc: sdhci-acpi: Set MMC_CAP_CMD_DURING_TFR for Intel eMMC controllers

[Adrian Hunter]

Set MMC_CAP_CMD_DURING_TFR for Intel BYT and related eMMC host controllers.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci-acpi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
index 458ffb7637e5..ec1b99f89d4a 100644
--- a/drivers/mmc/host/sdhci-acpi.c
+++ b/drivers/mmc/host/sdhci-acpi.c
@@ -274,7 +274,7 @@ static const struct sdhci_acpi_slot sdhci_acpi_slot_int_emmc = {
 	.chip    = &sdhci_acpi_chip_int,
 	.caps    = MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE |
 		   MMC_CAP_HW_RESET | MMC_CAP_1_8V_DDR |
-		   MMC_CAP_WAIT_WHILE_BUSY,
+		   MMC_CAP_CMD_DURING_TFR | MMC_CAP_WAIT_WHILE_BUSY,
 	.caps2   = MMC_CAP2_HC_ERASE_SZ,
 	.flags   = SDHCI_ACPI_RUNTIME_PM,
 	.quirks  = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
-- 
1.9.1

[PATCH RFC 23/46] mmc: queue: Fix queue thread wake-up

[Adrian Hunter]

The only time the driver sleeps expecting to be woken upon the arrival of
a new request, is when the dispatch queue is empty. The only time that it
is known whether the dispatch queue is empty is after NULL is returned
from blk_fetch_request() while under the queue lock.

Recognizing those facts, simplify the synchronization between the queue
thread and the request function. A couple of flags tell the request
function what to do, and the queue lock and barriers associated with
wake-ups ensure synchronization.

The result is simpler and allows the removal of the context_info lock.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/block.c |  7 -------
 drivers/mmc/card/queue.c | 35 +++++++++++++++++++++--------------
 drivers/mmc/card/queue.h |  1 +
 drivers/mmc/core/core.c  |  6 ------
 include/linux/mmc/host.h |  2 --
 5 files changed, 22 insertions(+), 29 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 5345730c6eeb..7e69dceaf645 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -2146,8 +2146,6 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 	int ret;
 	struct mmc_blk_data *md = mq->data;
 	struct mmc_card *card = md->queue.card;
-	struct mmc_host *host = card->host;
-	unsigned long flags;
 	unsigned int cmd_flags = req ? req->cmd_flags : 0;
 
 	if (req && !mq->mqrq_prev->req)
@@ -2178,11 +2176,6 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 			mmc_blk_issue_rw_rq(mq, NULL);
 		ret = mmc_blk_issue_flush(mq, req);
 	} else {
-		if (!req && host->areq) {
-			spin_lock_irqsave(&host->context_info.lock, flags);
-			host->context_info.is_waiting_last_req = true;
-			spin_unlock_irqrestore(&host->context_info.lock, flags);
-		}
 		ret = mmc_blk_issue_rw_rq(mq, req);
 	}
 
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 6f4323c6d653..7469d0d99027 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -50,6 +50,7 @@ static int mmc_queue_thread(void *d)
 {
 	struct mmc_queue *mq = d;
 	struct request_queue *q = mq->queue;
+	struct mmc_context_info *cntx = &mq->card->host->context_info;
 
 	current->flags |= PF_MEMALLOC;
 
@@ -61,6 +62,19 @@ static int mmc_queue_thread(void *d)
 		spin_lock_irq(q->queue_lock);
 		set_current_state(TASK_INTERRUPTIBLE);
 		req = blk_fetch_request(q);
+		mq->asleep = false;
+		cntx->is_waiting_last_req = false;
+		cntx->is_new_req = false;
+		if (!req) {
+			/*
+			 * Dispatch queue is empty so set flags for
+			 * mmc_request_fn() to wake us up.
+			 */
+			if (mq->mqrq_prev->req)
+				cntx->is_waiting_last_req = true;
+			else
+				mq->asleep = true;
+		}
 		mq->mqrq_cur->req = req;
 		spin_unlock_irq(q->queue_lock);
 
@@ -112,7 +126,6 @@ static void mmc_request_fn(struct request_queue *q)
 {
 	struct mmc_queue *mq = q->queuedata;
 	struct request *req;
-	unsigned long flags;
 	struct mmc_context_info *cntx;
 
 	if (!mq) {
@@ -124,19 +137,13 @@ static void mmc_request_fn(struct request_queue *q)
 	}
 
 	cntx = &mq->card->host->context_info;
-	if (!mq->mqrq_cur->req && mq->mqrq_prev->req) {
-		/*
-		 * New MMC request arrived when MMC thread may be
-		 * blocked on the previous request to be complete
-		 * with no current request fetched
-		 */
-		spin_lock_irqsave(&cntx->lock, flags);
-		if (cntx->is_waiting_last_req) {
-			cntx->is_new_req = true;
-			wake_up_interruptible(&cntx->wait);
-		}
-		spin_unlock_irqrestore(&cntx->lock, flags);
-	} else if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
+
+	if (cntx->is_waiting_last_req) {
+		cntx->is_new_req = true;
+		wake_up_interruptible(&cntx->wait);
+	}
+
+	if (mq->asleep)
 		wake_up_process(mq->thread);
 }
 
diff --git a/drivers/mmc/card/queue.h b/drivers/mmc/card/queue.h
index 36cddab57d77..872c82a83729 100644
--- a/drivers/mmc/card/queue.h
+++ b/drivers/mmc/card/queue.h
@@ -51,6 +51,7 @@ struct mmc_queue {
 	unsigned int		flags;
 #define MMC_QUEUE_SUSPENDED	(1 << 0)
 #define MMC_QUEUE_NEW_REQUEST	(1 << 1)
+	bool			asleep;
 
 	int			(*issue_fn)(struct mmc_queue *, struct request *);
 	void			*data;
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 8563dc9e1519..2c50883f3845 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -501,18 +501,14 @@ static int mmc_wait_for_data_req_done(struct mmc_host *host,
 	struct mmc_command *cmd;
 	struct mmc_context_info *context_info = &host->context_info;
 	int err;
-	unsigned long flags;
 
 	while (1) {
 		wait_event_interruptible(context_info->wait,
 				(context_info->is_done_rcv ||
 				 context_info->is_new_req));
-		spin_lock_irqsave(&context_info->lock, flags);
 		context_info->is_waiting_last_req = false;
-		spin_unlock_irqrestore(&context_info->lock, flags);
 		if (context_info->is_done_rcv) {
 			context_info->is_done_rcv = false;
-			context_info->is_new_req = false;
 			cmd = mrq->cmd;
 
 			if (!cmd->error || !cmd->retries ||
@@ -531,7 +527,6 @@ static int mmc_wait_for_data_req_done(struct mmc_host *host,
 				continue; /* wait for done/new event again */
 			}
 		} else if (context_info->is_new_req) {
-			context_info->is_new_req = false;
 			if (!next_req)
 				return MMC_BLK_NEW_REQUEST;
 		}
@@ -2939,7 +2934,6 @@ void mmc_unregister_pm_notifier(struct mmc_host *host)
  */
 void mmc_init_context_info(struct mmc_host *host)
 {
-	spin_lock_init(&host->context_info.lock);
 	host->context_info.is_new_req = false;
 	host->context_info.is_done_rcv = false;
 	host->context_info.is_waiting_last_req = false;
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index af247e4c75d5..567c6c14c9f3 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -198,14 +198,12 @@ struct mmc_slot {
  * @is_new_req		wake up reason was new request
  * @is_waiting_last_req	mmc context waiting for single running request
  * @wait		wait queue
- * @lock		lock to protect data fields
  */
 struct mmc_context_info {
 	bool			is_done_rcv;
 	bool			is_new_req;
 	bool			is_waiting_last_req;
 	wait_queue_head_t	wait;
-	spinlock_t		lock;
 };
 
 struct regulator;
-- 
1.9.1

[PATCH RFC 24/46] mmc: queue: Factor out mmc_queue_alloc_bounce_bufs()

[Adrian Hunter]

In preparation for supporting a queue of requests, factor out
mmc_queue_alloc_bounce_bufs().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/queue.c | 45 +++++++++++++++++++++++++++------------------
 1 file changed, 27 insertions(+), 18 deletions(-)

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 7469d0d99027..5e60216ca7d7 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -183,6 +183,31 @@ static void mmc_queue_setup_discard(struct request_queue *q,
 		queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q);
 }
 
+static bool mmc_queue_alloc_bounce_bufs(struct mmc_queue *mq,
+					unsigned int bouncesz)
+{
+	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
+	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
+
+	mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
+	if (!mqrq_cur->bounce_buf) {
+		pr_warn("%s: unable to allocate bounce cur buffer\n",
+			mmc_card_name(mq->card));
+		return false;
+	}
+
+	mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
+	if (!mqrq_prev->bounce_buf) {
+		pr_warn("%s: unable to allocate bounce prev buffer\n",
+			mmc_card_name(mq->card));
+		kfree(mqrq_cur->bounce_buf);
+		mqrq_cur->bounce_buf = NULL;
+		return false;
+	}
+
+	return true;
+}
+
 /**
  * mmc_init_queue - initialise a queue structure.
  * @mq: mmc queue
@@ -232,24 +257,8 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 		if (bouncesz > (host->max_blk_count * 512))
 			bouncesz = host->max_blk_count * 512;
 
-		if (bouncesz > 512) {
-			mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
-			if (!mqrq_cur->bounce_buf) {
-				pr_warn("%s: unable to allocate bounce cur buffer\n",
-					mmc_card_name(card));
-			} else {
-				mqrq_prev->bounce_buf =
-						kmalloc(bouncesz, GFP_KERNEL);
-				if (!mqrq_prev->bounce_buf) {
-					pr_warn("%s: unable to allocate bounce prev buffer\n",
-						mmc_card_name(card));
-					kfree(mqrq_cur->bounce_buf);
-					mqrq_cur->bounce_buf = NULL;
-				}
-			}
-		}
-
-		if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) {
+		if (bouncesz > 512 &&
+		    mmc_queue_alloc_bounce_bufs(mq, bouncesz)) {
 			blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
 			blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
 			blk_queue_max_segments(mq->queue, bouncesz / 512);
-- 
1.9.1

[PATCH RFC 25/46] mmc: queue: Factor out mmc_queue_alloc_bounce_sgs()

[Adrian Hunter]

In preparation for supporting a queue of requests, factor out
mmc_queue_alloc_bounce_sgs().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/queue.c | 44 ++++++++++++++++++++++++++++----------------
 1 file changed, 28 insertions(+), 16 deletions(-)

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 5e60216ca7d7..9927eda50cbb 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -208,6 +208,30 @@ static bool mmc_queue_alloc_bounce_bufs(struct mmc_queue *mq,
 	return true;
 }
 
+static int mmc_queue_alloc_bounce_sgs(struct mmc_queue *mq,
+				      unsigned int bouncesz)
+{
+	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
+	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
+	int ret;
+
+	mqrq_cur->sg = mmc_alloc_sg(1, &ret);
+	if (ret)
+		return ret;
+
+	mqrq_cur->bounce_sg = mmc_alloc_sg(bouncesz / 512, &ret);
+	if (ret)
+		return ret;
+
+	mqrq_prev->sg = mmc_alloc_sg(1, &ret);
+	if (ret)
+		return ret;
+
+	mqrq_prev->bounce_sg = mmc_alloc_sg(bouncesz / 512, &ret);
+
+	return ret;
+}
+
 /**
  * mmc_init_queue - initialise a queue structure.
  * @mq: mmc queue
@@ -222,6 +246,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 {
 	struct mmc_host *host = card->host;
 	u64 limit = BLK_BOUNCE_HIGH;
+	bool bounce = false;
 	int ret;
 	struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
 	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
@@ -264,28 +289,15 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 			blk_queue_max_segments(mq->queue, bouncesz / 512);
 			blk_queue_max_segment_size(mq->queue, bouncesz);
 
-			mqrq_cur->sg = mmc_alloc_sg(1, &ret);
-			if (ret)
-				goto cleanup_queue;
-
-			mqrq_cur->bounce_sg =
-				mmc_alloc_sg(bouncesz / 512, &ret);
-			if (ret)
-				goto cleanup_queue;
-
-			mqrq_prev->sg = mmc_alloc_sg(1, &ret);
-			if (ret)
-				goto cleanup_queue;
-
-			mqrq_prev->bounce_sg =
-				mmc_alloc_sg(bouncesz / 512, &ret);
+			ret = mmc_queue_alloc_bounce_sgs(mq, bouncesz);
 			if (ret)
 				goto cleanup_queue;
+			bounce = true;
 		}
 	}
 #endif
 
-	if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) {
+	if (!bounce) {
 		blk_queue_bounce_limit(mq->queue, limit);
 		blk_queue_max_hw_sectors(mq->queue,
 			min(host->max_blk_count, host->max_req_size / 512));
-- 
1.9.1

[PATCH RFC 26/46] mmc: queue: Factor out mmc_queue_alloc_sgs()

[Adrian Hunter]

In preparation for supporting a queue of requests, factor out
mmc_queue_alloc_sgs().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/queue.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 9927eda50cbb..3c41bc58510b 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -232,6 +232,21 @@ static int mmc_queue_alloc_bounce_sgs(struct mmc_queue *mq,
 	return ret;
 }
 
+static int mmc_queue_alloc_sgs(struct mmc_queue *mq, int max_segs)
+{
+	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
+	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
+	int ret;
+
+	mqrq_cur->sg = mmc_alloc_sg(max_segs, &ret);
+	if (ret)
+		return ret;
+
+	mqrq_prev->sg = mmc_alloc_sg(max_segs, &ret);
+
+	return ret;
+}
+
 /**
  * mmc_init_queue - initialise a queue structure.
  * @mq: mmc queue
@@ -304,12 +319,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 		blk_queue_max_segments(mq->queue, host->max_segs);
 		blk_queue_max_segment_size(mq->queue, host->max_seg_size);
 
-		mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret);
-		if (ret)
-			goto cleanup_queue;
-
-
-		mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);
+		ret = mmc_queue_alloc_sgs(mq, host->max_segs);
 		if (ret)
 			goto cleanup_queue;
 	}
-- 
1.9.1

[PATCH RFC 27/46] mmc: queue: Factor out mmc_queue_reqs_free_bufs()

[Adrian Hunter]

In preparation for supporting a queue of requests, factor out
mmc_queue_reqs_free_bufs().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/queue.c | 65 +++++++++++++++++++-----------------------------
 1 file changed, 26 insertions(+), 39 deletions(-)

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 3c41bc58510b..b10bae73d157 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -247,6 +247,27 @@ static int mmc_queue_alloc_sgs(struct mmc_queue *mq, int max_segs)
 	return ret;
 }
 
+static void mmc_queue_reqs_free_bufs(struct mmc_queue *mq)
+{
+	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
+	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
+
+	kfree(mqrq_cur->bounce_sg);
+	mqrq_cur->bounce_sg = NULL;
+	kfree(mqrq_prev->bounce_sg);
+	mqrq_prev->bounce_sg = NULL;
+
+	kfree(mqrq_cur->sg);
+	mqrq_cur->sg = NULL;
+	kfree(mqrq_cur->bounce_buf);
+	mqrq_cur->bounce_buf = NULL;
+
+	kfree(mqrq_prev->sg);
+	mqrq_prev->sg = NULL;
+	kfree(mqrq_prev->bounce_buf);
+	mqrq_prev->bounce_buf = NULL;
+}
+
 /**
  * mmc_init_queue - initialise a queue structure.
  * @mq: mmc queue
@@ -263,8 +284,6 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 	u64 limit = BLK_BOUNCE_HIGH;
 	bool bounce = false;
 	int ret;
-	struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
-	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 
 	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
 		limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
@@ -274,8 +293,8 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 	if (!mq->queue)
 		return -ENOMEM;
 
-	mq->mqrq_cur = mqrq_cur;
-	mq->mqrq_prev = mqrq_prev;
+	mq->mqrq_cur = &mq->mqrq[0];
+	mq->mqrq_prev = &mq->mqrq[1];
 	mq->queue->queuedata = mq;
 
 	blk_queue_prep_rq(mq->queue, mmc_prep_request);
@@ -331,27 +350,13 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 
 	if (IS_ERR(mq->thread)) {
 		ret = PTR_ERR(mq->thread);
-		goto free_bounce_sg;
+		goto cleanup_queue;
 	}
 
 	return 0;
- free_bounce_sg:
-	kfree(mqrq_cur->bounce_sg);
-	mqrq_cur->bounce_sg = NULL;
-	kfree(mqrq_prev->bounce_sg);
-	mqrq_prev->bounce_sg = NULL;
 
  cleanup_queue:
-	kfree(mqrq_cur->sg);
-	mqrq_cur->sg = NULL;
-	kfree(mqrq_cur->bounce_buf);
-	mqrq_cur->bounce_buf = NULL;
-
-	kfree(mqrq_prev->sg);
-	mqrq_prev->sg = NULL;
-	kfree(mqrq_prev->bounce_buf);
-	mqrq_prev->bounce_buf = NULL;
-
+	mmc_queue_reqs_free_bufs(mq);
 	blk_cleanup_queue(mq->queue);
 	return ret;
 }
@@ -360,8 +365,6 @@ void mmc_cleanup_queue(struct mmc_queue *mq)
 {
 	struct request_queue *q = mq->queue;
 	unsigned long flags;
-	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
-	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
 
 	/* Make sure the queue isn't suspended, as that will deadlock */
 	mmc_queue_resume(mq);
@@ -375,23 +378,7 @@ void mmc_cleanup_queue(struct mmc_queue *mq)
 	blk_start_queue(q);
 	spin_unlock_irqrestore(q->queue_lock, flags);
 
-	kfree(mqrq_cur->bounce_sg);
-	mqrq_cur->bounce_sg = NULL;
-
-	kfree(mqrq_cur->sg);
-	mqrq_cur->sg = NULL;
-
-	kfree(mqrq_cur->bounce_buf);
-	mqrq_cur->bounce_buf = NULL;
-
-	kfree(mqrq_prev->bounce_sg);
-	mqrq_prev->bounce_sg = NULL;
-
-	kfree(mqrq_prev->sg);
-	mqrq_prev->sg = NULL;
-
-	kfree(mqrq_prev->bounce_buf);
-	mqrq_prev->bounce_buf = NULL;
+	mmc_queue_reqs_free_bufs(mq);
 
 	mq->card = NULL;
 }
-- 
1.9.1

[PATCH RFC 28/46] mmc: queue: Introduce queue depth

[Adrian Hunter]

Add a mmc_queue member to record the size of the queue, which currently
supports 2 requests on-the-go at a time.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/queue.c | 4 ++++
 drivers/mmc/card/queue.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index b10bae73d157..1a8e5d45f74d 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -293,6 +293,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 	if (!mq->queue)
 		return -ENOMEM;
 
+	mq->qdepth = 2;
 	mq->mqrq_cur = &mq->mqrq[0];
 	mq->mqrq_prev = &mq->mqrq[1];
 	mq->queue->queuedata = mq;
@@ -390,6 +391,9 @@ int mmc_packed_init(struct mmc_queue *mq, struct mmc_card *card)
 	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 	int ret = 0;
 
+	/* Queue depth is only ever 2 with packed commands */
+	if (mq->qdepth != 2)
+		return -EINVAL;
 
 	mqrq_cur->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
 	if (!mqrq_cur->packed) {
diff --git a/drivers/mmc/card/queue.h b/drivers/mmc/card/queue.h
index 872c82a83729..b687a90c4ea1 100644
--- a/drivers/mmc/card/queue.h
+++ b/drivers/mmc/card/queue.h
@@ -59,6 +59,7 @@ struct mmc_queue {
 	struct mmc_queue_req	mqrq[2];
 	struct mmc_queue_req	*mqrq_cur;
 	struct mmc_queue_req	*mqrq_prev;
+	int			qdepth;
 };
 
 extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *,
-- 
1.9.1

[PATCH RFC 29/46] mmc: queue: Use queue depth to allocate and free

[Adrian Hunter]

Instead of allocating resources for 2 slots in the queue, allow for an
arbitrary number.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/queue.c | 103 +++++++++++++++++++++--------------------------
 1 file changed, 46 insertions(+), 57 deletions(-)

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 1a8e5d45f74d..dba991979a6b 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -186,86 +186,75 @@ static void mmc_queue_setup_discard(struct request_queue *q,
 static bool mmc_queue_alloc_bounce_bufs(struct mmc_queue *mq,
 					unsigned int bouncesz)
 {
-	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
-	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
-
-	mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
-	if (!mqrq_cur->bounce_buf) {
-		pr_warn("%s: unable to allocate bounce cur buffer\n",
-			mmc_card_name(mq->card));
-		return false;
-	}
+	int i;
 
-	mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
-	if (!mqrq_prev->bounce_buf) {
-		pr_warn("%s: unable to allocate bounce prev buffer\n",
-			mmc_card_name(mq->card));
-		kfree(mqrq_cur->bounce_buf);
-		mqrq_cur->bounce_buf = NULL;
-		return false;
+	for (i = 0; i < mq->qdepth; i++) {
+		mq->mqrq[i].bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
+		if (!mq->mqrq[i].bounce_buf)
+			goto out_err;
 	}
 
 	return true;
+
+out_err:
+	while (--i >= 0) {
+		kfree(mq->mqrq[i].bounce_buf);
+		mq->mqrq[i].bounce_buf = NULL;
+	}
+	pr_warn("%s: unable to allocate bounce buffers\n",
+		mmc_card_name(mq->card));
+	return false;
 }
 
 static int mmc_queue_alloc_bounce_sgs(struct mmc_queue *mq,
 				      unsigned int bouncesz)
 {
-	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
-	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
-	int ret;
-
-	mqrq_cur->sg = mmc_alloc_sg(1, &ret);
-	if (ret)
-		return ret;
+	int i, ret;
 
-	mqrq_cur->bounce_sg = mmc_alloc_sg(bouncesz / 512, &ret);
-	if (ret)
-		return ret;
-
-	mqrq_prev->sg = mmc_alloc_sg(1, &ret);
-	if (ret)
-		return ret;
+	for (i = 0; i < mq->qdepth; i++) {
+		mq->mqrq[i].sg = mmc_alloc_sg(1, &ret);
+		if (ret)
+			return ret;
 
-	mqrq_prev->bounce_sg = mmc_alloc_sg(bouncesz / 512, &ret);
+		mq->mqrq[i].bounce_sg = mmc_alloc_sg(bouncesz / 512, &ret);
+		if (ret)
+			return ret;
+	}
 
-	return ret;
+	return 0;
 }
 
 static int mmc_queue_alloc_sgs(struct mmc_queue *mq, int max_segs)
 {
-	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
-	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
-	int ret;
+	int i, ret;
 
-	mqrq_cur->sg = mmc_alloc_sg(max_segs, &ret);
-	if (ret)
-		return ret;
+	for (i = 0; i < mq->qdepth; i++) {
+		mq->mqrq[i].sg = mmc_alloc_sg(max_segs, &ret);
+		if (ret)
+			return ret;
+	}
 
-	mqrq_prev->sg = mmc_alloc_sg(max_segs, &ret);
+	return 0;
+}
 
-	return ret;
+static void mmc_queue_req_free_bufs(struct mmc_queue_req *mqrq)
+{
+	kfree(mqrq->bounce_sg);
+	mqrq->bounce_sg = NULL;
+
+	kfree(mqrq->sg);
+	mqrq->sg = NULL;
+
+	kfree(mqrq->bounce_buf);
+	mqrq->bounce_buf = NULL;
 }
 
 static void mmc_queue_reqs_free_bufs(struct mmc_queue *mq)
 {
-	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
-	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
-
-	kfree(mqrq_cur->bounce_sg);
-	mqrq_cur->bounce_sg = NULL;
-	kfree(mqrq_prev->bounce_sg);
-	mqrq_prev->bounce_sg = NULL;
-
-	kfree(mqrq_cur->sg);
-	mqrq_cur->sg = NULL;
-	kfree(mqrq_cur->bounce_buf);
-	mqrq_cur->bounce_buf = NULL;
-
-	kfree(mqrq_prev->sg);
-	mqrq_prev->sg = NULL;
-	kfree(mqrq_prev->bounce_buf);
-	mqrq_prev->bounce_buf = NULL;
+	int i;
+
+	for (i = 0; i < mq->qdepth; i++)
+		mmc_queue_req_free_bufs(&mq->mqrq[i]);
 }
 
 /**
-- 
1.9.1

[PATCH RFC 30/46] mmc: queue: Allocate queue of size qdepth

[Adrian Hunter]

Now that the queue resources are allocated according to the size of the
queue, it is possible to allocate the queue to be an arbitrary size.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/queue.c | 6 +++++-
 drivers/mmc/card/queue.h | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index dba991979a6b..4463d33094e4 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -272,7 +272,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 	struct mmc_host *host = card->host;
 	u64 limit = BLK_BOUNCE_HIGH;
 	bool bounce = false;
-	int ret;
+	int ret = -ENOMEM;
 
 	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
 		limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
@@ -283,6 +283,10 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 		return -ENOMEM;
 
 	mq->qdepth = 2;
+	mq->mqrq = kcalloc(mq->qdepth, sizeof(struct mmc_queue_req),
+			   GFP_KERNEL);
+	if (!mq->mqrq)
+		goto cleanup_queue;
 	mq->mqrq_cur = &mq->mqrq[0];
 	mq->mqrq_prev = &mq->mqrq[1];
 	mq->queue->queuedata = mq;
diff --git a/drivers/mmc/card/queue.h b/drivers/mmc/card/queue.h
index b687a90c4ea1..bb8dad281f72 100644
--- a/drivers/mmc/card/queue.h
+++ b/drivers/mmc/card/queue.h
@@ -56,7 +56,7 @@ struct mmc_queue {
 	int			(*issue_fn)(struct mmc_queue *, struct request *);
 	void			*data;
 	struct request_queue	*queue;
-	struct mmc_queue_req	mqrq[2];
+	struct mmc_queue_req	*mqrq;
 	struct mmc_queue_req	*mqrq_cur;
 	struct mmc_queue_req	*mqrq_prev;
 	int			qdepth;
-- 
1.9.1

[PATCH RFC 31/46] mmc: mmc: Add Command Queue definitions

[Adrian Hunter]

Add definitions relating to Command Queuing.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/core/mmc.c   | 19 +++++++++++++++++++
 include/linux/mmc/card.h |  3 +++
 include/linux/mmc/mmc.h  | 17 +++++++++++++++++
 3 files changed, 39 insertions(+)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 97a664f758b0..eb1781b066f3 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -599,6 +599,23 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
 			(ext_csd[EXT_CSD_SUPPORTED_MODE] & 0x1) &&
 			!(ext_csd[EXT_CSD_FW_CONFIG] & 0x1);
 	}
+
+	/* eMMC v5.1 or later */
+	if (card->ext_csd.rev >= 8) {
+		card->ext_csd.cmdq_support = ext_csd[EXT_CSD_CMDQ_SUPPORT] &
+					     EXT_CSD_CMDQ_SUPPORTED;
+		card->ext_csd.cmdq_depth = (ext_csd[EXT_CSD_CMDQ_DEPTH] &
+					    EXT_CSD_CMDQ_DEPTH_MASK) + 1;
+		if (card->ext_csd.cmdq_depth <= 2) {
+			card->ext_csd.cmdq_support = false;
+			card->ext_csd.cmdq_depth = 0;
+		}
+		if (card->ext_csd.cmdq_support) {
+			pr_debug("%s: Command Queue supported depth %u\n",
+				 mmc_hostname(card->host),
+				 card->ext_csd.cmdq_depth);
+		}
+	}
 out:
 	return err;
 }
@@ -733,6 +750,7 @@ MMC_DEV_ATTR(enhanced_area_offset, "%llu\n",
 MMC_DEV_ATTR(enhanced_area_size, "%u\n", card->ext_csd.enhanced_area_size);
 MMC_DEV_ATTR(raw_rpmb_size_mult, "%#x\n", card->ext_csd.raw_rpmb_size_mult);
 MMC_DEV_ATTR(rel_sectors, "%#x\n", card->ext_csd.rel_sectors);
+MMC_DEV_ATTR(cmdq_en, "%d\n", card->ext_csd.cmdq_en);
 
 static ssize_t mmc_fwrev_show(struct device *dev,
 			      struct device_attribute *attr,
@@ -768,6 +786,7 @@ static struct attribute *mmc_std_attrs[] = {
 	&dev_attr_enhanced_area_size.attr,
 	&dev_attr_raw_rpmb_size_mult.attr,
 	&dev_attr_rel_sectors.attr,
+	&dev_attr_cmdq_en.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(mmc_std);
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 22defc2a83b7..1c380271038f 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -89,6 +89,9 @@ struct mmc_ext_csd {
 	unsigned int		boot_ro_lock;		/* ro lock support */
 	bool			boot_ro_lockable;
 	bool			ffu_capable;	/* Firmware upgrade support */
+	bool			cmdq_en;	/* Command Queue enabled */
+	bool			cmdq_support;	/* Command Queue supported */
+	unsigned int		cmdq_depth;	/* Command Queue depth */
 #define MMC_FIRMWARE_LEN 8
 	u8			fwrev[MMC_FIRMWARE_LEN];  /* FW version */
 	u8			raw_exception_status;	/* 54 */
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index c376209c70ef..672730acc705 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -84,6 +84,13 @@
 #define MMC_APP_CMD              55   /* ac   [31:16] RCA        R1  */
 #define MMC_GEN_CMD              56   /* adtc [0] RD/WR          R1  */
 
+  /* class 11 */
+#define MMC_QUE_TASK_PARAMS      44   /* ac   [20:16] task id    R1  */
+#define MMC_QUE_TASK_ADDR        45   /* ac   [31:0] data addr   R1  */
+#define MMC_EXECUTE_READ_TASK    46   /* adtc [20:16] task id    R1  */
+#define MMC_EXECUTE_WRITE_TASK   47   /* adtc [20:16] task id    R1  */
+#define MMC_CMDQ_TASK_MGMT       48   /* ac   [20:16] task id    R1b */
+
 static inline bool mmc_op_multi(u32 opcode)
 {
 	return opcode == MMC_WRITE_MULTIPLE_BLOCK ||
@@ -272,6 +279,7 @@ struct _mmc_csd {
  * EXT_CSD fields
  */
 
+#define EXT_CSD_CMDQ_MODE_EN		15	/* R/W */
 #define EXT_CSD_FLUSH_CACHE		32      /* W */
 #define EXT_CSD_CACHE_CTRL		33      /* R/W */
 #define EXT_CSD_POWER_OFF_NOTIFICATION	34	/* R/W */
@@ -331,6 +339,8 @@ struct _mmc_csd {
 #define EXT_CSD_CACHE_SIZE		249	/* RO, 4 bytes */
 #define EXT_CSD_PWR_CL_DDR_200_360	253	/* RO */
 #define EXT_CSD_FIRMWARE_VERSION	254	/* RO, 8 bytes */
+#define EXT_CSD_CMDQ_DEPTH		307	/* RO */
+#define EXT_CSD_CMDQ_SUPPORT		308	/* RO */
 #define EXT_CSD_SUPPORTED_MODE		493	/* RO */
 #define EXT_CSD_TAG_UNIT_SIZE		498	/* RO */
 #define EXT_CSD_DATA_TAG_SUPPORT	499	/* RO */
@@ -438,6 +448,13 @@ struct _mmc_csd {
 #define EXT_CSD_MANUAL_BKOPS_MASK	0x01
 
 /*
+ * Command Queue
+ */
+#define EXT_CSD_CMDQ_MODE_ENABLED	BIT(0)
+#define EXT_CSD_CMDQ_DEPTH_MASK		GENMASK(4, 0)
+#define EXT_CSD_CMDQ_SUPPORTED		BIT(0)
+
+/*
  * MMC_SWITCH access modes
  */
 
-- 
1.9.1

[PATCH RFC 32/46] mmc: mmc: Add functions to enable / disable the Command Queue

[Adrian Hunter]

Add helper functions to enable or disable the Command Queue.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/core/mmc_ops.c | 27 +++++++++++++++++++++++++++
 include/linux/mmc/core.h   |  2 ++
 2 files changed, 29 insertions(+)

diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 62355bda608f..d3878e5ed123 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -790,3 +790,30 @@ int mmc_can_ext_csd(struct mmc_card *card)
 {
 	return (card && card->csd.mmca_vsn > CSD_SPEC_VER_3);
 }
+
+int mmc_cmdq_switch(struct mmc_card *card, int enable)
+{
+	int err;
+
+	if (!card->ext_csd.cmdq_support)
+		return -EOPNOTSUPP;
+
+	err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_CMDQ_MODE_EN,
+			 enable, card->ext_csd.generic_cmd6_time);
+	if (!err)
+		card->ext_csd.cmdq_en = enable;
+
+	return err;
+}
+
+int mmc_cmdq_enable(struct mmc_card *card)
+{
+	return mmc_cmdq_switch(card, EXT_CSD_CMDQ_MODE_ENABLED);
+}
+EXPORT_SYMBOL_GPL(mmc_cmdq_enable);
+
+int mmc_cmdq_disable(struct mmc_card *card)
+{
+	return mmc_cmdq_switch(card, 0);
+}
+EXPORT_SYMBOL_GPL(mmc_cmdq_disable);
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 368bed70aa9d..63dc01257852 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -161,6 +161,8 @@ extern void mmc_start_bkops(struct mmc_card *card, bool from_exception);
 extern int mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int);
 extern int mmc_send_tuning(struct mmc_host *host, u32 opcode, int *cmd_error);
 extern int mmc_get_ext_csd(struct mmc_card *card, u8 **new_ext_csd);
+extern int mmc_cmdq_enable(struct mmc_card *card);
+extern int mmc_cmdq_disable(struct mmc_card *card);
 
 #define MMC_ERASE_ARG		0x00000000
 #define MMC_SECURE_ERASE_ARG	0x80000000
-- 
1.9.1

[PATCH RFC 33/46] mmc: mmc_test: Disable Command Queue while mmc_test is used

[Adrian Hunter]

Normal read and write commands may not be used while the command queue is
enabled. Disable the Command Queue when mmc_test is probed and re-enable it
when it is removed.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/mmc_test.c | 8 ++++++++
 drivers/mmc/core/mmc.c      | 7 +++++++
 include/linux/mmc/card.h    | 1 +
 3 files changed, 16 insertions(+)

diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
index 5a8dc5a76e0d..d6566747dd0a 100644
--- a/drivers/mmc/card/mmc_test.c
+++ b/drivers/mmc/card/mmc_test.c
@@ -3240,6 +3240,12 @@ static int mmc_test_probe(struct mmc_card *card)
 	if (ret)
 		return ret;
 
+	if (card->ext_csd.cmdq_en) {
+		ret = mmc_cmdq_disable(card);
+		if (ret)
+			return ret;
+	}
+
 	dev_info(&card->dev, "Card claimed for testing.\n");
 
 	return 0;
@@ -3247,6 +3253,8 @@ static int mmc_test_probe(struct mmc_card *card)
 
 static void mmc_test_remove(struct mmc_card *card)
 {
+	if (card->reenable_cmdq)
+		mmc_cmdq_enable(card);
 	mmc_test_free_result(card);
 	mmc_test_free_dbgfs_file(card);
 }
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index eb1781b066f3..2e54daa237f6 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1736,6 +1736,13 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	}
 
 	/*
+	 * In some cases (e.g. RPMB or mmc_test), the Command Queue must be
+	 * disabled for a time, so a flag is needed to indicate to re-enable the
+	 * Command Queue.
+	 */
+	card->reenable_cmdq = card->ext_csd.cmdq_en;
+
+	/*
 	 * The mandatory minimum values are defined for packed command.
 	 * read: 5, write: 3
 	 */
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 1c380271038f..2abcedc1e9e9 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -284,6 +284,7 @@ struct mmc_card {
 #define MMC_QUIRK_BROKEN_IRQ_POLLING	(1<<11)	/* Polling SDIO_CCCR_INTx could create a fake interrupt */
 #define MMC_QUIRK_TRIM_BROKEN	(1<<12)		/* Skip trim */
 
+	bool			reenable_cmdq;	/* Re-enable Command Queue */
 
 	unsigned int		erase_size;	/* erase size in sectors */
  	unsigned int		erase_shift;	/* if erase unit is power 2 */
-- 
1.9.1

[PATCH RFC V2 33/46] mmc: mmc_test: Disable Command Queue while mmc_test is used

[Adrian Hunter]

Normal read and write commands may not be used while the command queue is
enabled. Disable the Command Queue when mmc_test is probed and re-enable it
when it is removed.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---


V2: Claim / release the host when enabling / disabling CMDQ


 drivers/mmc/card/mmc_test.c | 13 +++++++++++++
 drivers/mmc/core/mmc.c      |  7 +++++++
 include/linux/mmc/card.h    |  1 +
 3 files changed, 21 insertions(+)

diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
index 5a8dc5a76e0d..7dee9e5a8cfb 100644
--- a/drivers/mmc/card/mmc_test.c
+++ b/drivers/mmc/card/mmc_test.c
@@ -3240,6 +3240,14 @@ static int mmc_test_probe(struct mmc_card *card)
 	if (ret)
 		return ret;
 
+	if (card->ext_csd.cmdq_en) {
+		mmc_claim_host(card->host);
+		ret = mmc_cmdq_disable(card);
+		mmc_release_host(card->host);
+		if (ret)
+			return ret;
+	}
+
 	dev_info(&card->dev, "Card claimed for testing.\n");
 
 	return 0;
@@ -3247,6 +3255,11 @@ static int mmc_test_probe(struct mmc_card *card)
 
 static void mmc_test_remove(struct mmc_card *card)
 {
+	if (card->reenable_cmdq) {
+		mmc_claim_host(card->host);
+		mmc_cmdq_enable(card);
+		mmc_release_host(card->host);
+	}
 	mmc_test_free_result(card);
 	mmc_test_free_dbgfs_file(card);
 }
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index eb1781b066f3..2e54daa237f6 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1736,6 +1736,13 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	}
 
 	/*
+	 * In some cases (e.g. RPMB or mmc_test), the Command Queue must be
+	 * disabled for a time, so a flag is needed to indicate to re-enable the
+	 * Command Queue.
+	 */
+	card->reenable_cmdq = card->ext_csd.cmdq_en;
+
+	/*
 	 * The mandatory minimum values are defined for packed command.
 	 * read: 5, write: 3
 	 */
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 1c380271038f..2abcedc1e9e9 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -284,6 +284,7 @@ struct mmc_card {
 #define MMC_QUIRK_BROKEN_IRQ_POLLING	(1<<11)	/* Polling SDIO_CCCR_INTx could create a fake interrupt */
 #define MMC_QUIRK_TRIM_BROKEN	(1<<12)		/* Skip trim */
 
+	bool			reenable_cmdq;	/* Re-enable Command Queue */
 
 	unsigned int		erase_size;	/* erase size in sectors */
  	unsigned int		erase_shift;	/* if erase unit is power 2 */
-- 
1.9.1

RE: [PATCH RFC V2 33/46] mmc: mmc_test: Disable Command Queue while mmc_test is used

[Venu Byravarasu]

> -----Original Message-----
> From: linux-mmc-owner@vger.kernel.org [mailto:linux-mmc-
> owner@vger.kernel.org] On Behalf Of Adrian Hunter
> Sent: Friday, June 10, 2016 4:15 PM
> To: Ulf Hansson
> Cc: linux-mmc; Alex Lemberg; Mateusz Nowak; Yuliy Izrailov; Jaehoon Chung;
> Dong Aisheng; Das Asutosh; Zhangfei Gao; Sujit Reddy Thumma; Dorfman
> Konstantin; David Griego; Sahitya Tummala; Harjani Ritesh
> Subject: [PATCH RFC V2 33/46] mmc: mmc_test: Disable Command Queue
> while mmc_test is used
> 
> Normal read and write commands may not be used while the command
> queue is enabled.

CQ may not be efficient when single rd/wr commands get issued with variable delays in between.
In such situations, CQ preparation for individual rd/wr cmds would be an unnecessary overhead. 
Hence even when CQ is supported, prefer CQ only when more than 1 data cmds are to be issued to device.

> 
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
> 
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may contain
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is prohibited.  If you are not the intended recipient, please contact the sender by
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-----------------------------------------------------------------------------------

Re: [PATCH RFC V2 33/46] mmc: mmc_test: Disable Command Queue while mmc_test is used

[Adrian Hunter]

On 10/06/16 13:59, Venu Byravarasu wrote:
>> -----Original Message-----
>> From: linux-mmc-owner@vger.kernel.org [mailto:linux-mmc-
>> owner@vger.kernel.org] On Behalf Of Adrian Hunter
>> Sent: Friday, June 10, 2016 4:15 PM
>> To: Ulf Hansson
>> Cc: linux-mmc; Alex Lemberg; Mateusz Nowak; Yuliy Izrailov; Jaehoon Chung;
>> Dong Aisheng; Das Asutosh; Zhangfei Gao; Sujit Reddy Thumma; Dorfman
>> Konstantin; David Griego; Sahitya Tummala; Harjani Ritesh
>> Subject: [PATCH RFC V2 33/46] mmc: mmc_test: Disable Command Queue
>> while mmc_test is used
>>
>> Normal read and write commands may not be used while the command
>> queue is enabled.
> 
> CQ may not be efficient when single rd/wr commands get issued with variable delays in between.
> In such situations, CQ preparation for individual rd/wr cmds would be an unnecessary overhead. 
> Hence even when CQ is supported, prefer CQ only when more than 1 data cmds are to be issued to device.

So you are suggesting toggling CQ on/off depending on whether there is more
than 1 data request?

Does that apply also to using hardware CQ i.e. a v5.1 host controller?

RE: [PATCH RFC V2 33/46] mmc: mmc_test: Disable Command Queue while mmc_test is used

[Venu Byravarasu]

> -----Original Message-----
> From: Adrian Hunter [mailto:adrian.hunter@intel.com]
> Sent: Friday, June 10, 2016 5:07 PM
> To: Venu Byravarasu; Ulf Hansson
> Cc: linux-mmc; Alex Lemberg; Mateusz Nowak; Yuliy Izrailov; Jaehoon Chung;
> Dong Aisheng; Das Asutosh; Zhangfei Gao; Dorfman Konstantin; David
> Griego; Sahitya Tummala; Harjani Ritesh
> Subject: Re: [PATCH RFC V2 33/46] mmc: mmc_test: Disable Command
> Queue while mmc_test is used
> 
> On 10/06/16 13:59, Venu Byravarasu wrote:
> >> -----Original Message-----
> >> From: linux-mmc-owner@vger.kernel.org [mailto:linux-mmc-
> >> owner@vger.kernel.org] On Behalf Of Adrian Hunter
> >> Sent: Friday, June 10, 2016 4:15 PM
> >> To: Ulf Hansson
> >> Cc: linux-mmc; Alex Lemberg; Mateusz Nowak; Yuliy Izrailov; Jaehoon
> >> Chung; Dong Aisheng; Das Asutosh; Zhangfei Gao; Sujit Reddy Thumma;
> >> Dorfman Konstantin; David Griego; Sahitya Tummala; Harjani Ritesh
> >> Subject: [PATCH RFC V2 33/46] mmc: mmc_test: Disable Command Queue
> >> while mmc_test is used
> >>
> >> Normal read and write commands may not be used while the command
> >> queue is enabled.
> >
> > CQ may not be efficient when single rd/wr commands get issued with
> variable delays in between.
> > In such situations, CQ preparation for individual rd/wr cmds would be an
> unnecessary overhead.
> > Hence even when CQ is supported, prefer CQ only when more than 1 data
> cmds are to be issued to device.
> 
> So you are suggesting toggling CQ on/off depending on whether there is
> more than 1 data request?

I didn't go thro' your implementation part for CQ yet & my comment was generic.

If preparation of CQ is taking N more operations than non-CQ command, then by not opting for CQ, you might save those N operations.
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[PATCH RFC 34/46] mmc: block: Disable Command Queue while RPMB is used

[Adrian Hunter]

RPMB does not allow Command Queue commands. Disable and re-enable the
Command Queue when switching.

Note that the driver only switches partitions when the queue is empty.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/block.c | 46 ++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 38 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 7e69dceaf645..4bd431999a1f 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -744,10 +744,41 @@ static const struct block_device_operations mmc_bdops = {
 #endif
 };
 
+static int mmc_blk_part_switch_pre(struct mmc_card *card,
+				   unsigned int part_type)
+{
+	int ret;
+
+	if (part_type == EXT_CSD_PART_CONFIG_ACC_RPMB) {
+		if (card->ext_csd.cmdq_en) {
+			ret = mmc_cmdq_disable(card);
+			if (ret)
+				return ret;
+		}
+		mmc_retune_pause(card->host);
+	}
+
+	return 0;
+}
+
+static int mmc_blk_part_switch_post(struct mmc_card *card,
+				    unsigned int part_type)
+{
+	int ret = 0;
+
+	if (part_type == EXT_CSD_PART_CONFIG_ACC_RPMB) {
+		mmc_retune_unpause(card->host);
+		if (card->reenable_cmdq && !card->ext_csd.cmdq_en)
+			ret = mmc_cmdq_enable(card);
+	}
+
+	return ret;
+}
+
 static inline int mmc_blk_part_switch(struct mmc_card *card,
 				      struct mmc_blk_data *md)
 {
-	int ret;
+	int ret = 0;
 	struct mmc_blk_data *main_md = dev_get_drvdata(&card->dev);
 
 	if (main_md->part_curr == md->part_type)
@@ -756,8 +787,9 @@ static inline int mmc_blk_part_switch(struct mmc_card *card,
 	if (mmc_card_mmc(card)) {
 		u8 part_config = card->ext_csd.part_config;
 
-		if (md->part_type == EXT_CSD_PART_CONFIG_ACC_RPMB)
-			mmc_retune_pause(card->host);
+		ret = mmc_blk_part_switch_pre(card, md->part_type);
+		if (ret)
+			return ret;
 
 		part_config &= ~EXT_CSD_PART_CONFIG_ACC_MASK;
 		part_config |= md->part_type;
@@ -766,19 +798,17 @@ static inline int mmc_blk_part_switch(struct mmc_card *card,
 				 EXT_CSD_PART_CONFIG, part_config,
 				 card->ext_csd.part_time);
 		if (ret) {
-			if (md->part_type == EXT_CSD_PART_CONFIG_ACC_RPMB)
-				mmc_retune_unpause(card->host);
+			mmc_blk_part_switch_post(card, md->part_type);
 			return ret;
 		}
 
 		card->ext_csd.part_config = part_config;
 
-		if (main_md->part_curr == EXT_CSD_PART_CONFIG_ACC_RPMB)
-			mmc_retune_unpause(card->host);
+		ret = mmc_blk_part_switch_post(card, main_md->part_curr);
 	}
 
 	main_md->part_curr = md->part_type;
-	return 0;
+	return ret;
 }
 
 static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
-- 
1.9.1

[PATCH RFC 35/46] mmc: core: Do not prepare a new request twice

[Adrian Hunter]

mmc_start_req() assumes it is never called with the new request already
prepared. That is true if the queue consists of only 2 requests, but is not
true for a longer queue. e.g. mmc_start_req() has a current and previous
request but still exits to queue a new request if the queue size is
greater than 2. In that case, when mmc_start_req() is called again, the
current request will have been prepared already. Fix by flagging if the
request has been prepared.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/core/core.c  | 12 +++++++++---
 include/linux/mmc/host.h |  1 +
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 2c50883f3845..df98d1e05932 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -657,8 +657,10 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
 	struct mmc_async_req *data = host->areq;
 
 	/* Prepare a new request */
-	if (areq)
+	if (areq && !areq->pre_req_done) {
+		areq->pre_req_done = true;
 		mmc_pre_req(host, areq->mrq, !host->areq);
+	}
 
 	if (host->areq) {
 		err = mmc_wait_for_data_req_done(host, host->areq->mrq,	areq);
@@ -694,12 +696,16 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
 	if (!err && areq)
 		start_err = __mmc_start_data_req(host, areq->mrq);
 
-	if (host->areq)
+	if (host->areq) {
+		host->areq->pre_req_done = false;
 		mmc_post_req(host, host->areq->mrq, 0);
+	}
 
 	 /* Cancel a prepared request if it was not started. */
-	if ((err || start_err) && areq)
+	if ((err || start_err) && areq) {
+		areq->pre_req_done = false;
 		mmc_post_req(host, areq->mrq, -EINVAL);
+	}
 
 	if (err)
 		host->areq = NULL;
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 567c6c14c9f3..c9ce8b0ae321 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -174,6 +174,7 @@ struct mmc_async_req {
 	 * Returns 0 if success otherwise non zero.
 	 */
 	int (*err_check) (struct mmc_card *, struct mmc_async_req *);
+	bool pre_req_done;
 };
 
 /**
-- 
1.9.1

[PATCH RFC 36/46] mmc: core: Export mmc_retune_hold() and mmc_retune_release()

[Adrian Hunter]

Re-tuning can only be done when the Command Queue is empty, when means
holding and releasing re-tuning from the block driver, so export those
functions.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/core/host.c  | 2 ++
 drivers/mmc/core/host.h  | 2 --
 include/linux/mmc/core.h | 3 +++
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index d7e86f9b3dab..946692cc0a06 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -112,6 +112,7 @@ void mmc_retune_hold(struct mmc_host *host)
 		host->retune_now = 1;
 	host->hold_retune += 1;
 }
+EXPORT_SYMBOL(mmc_retune_hold);
 
 void mmc_retune_release(struct mmc_host *host)
 {
@@ -120,6 +121,7 @@ void mmc_retune_release(struct mmc_host *host)
 	else
 		WARN_ON(1);
 }
+EXPORT_SYMBOL(mmc_retune_release);
 
 int mmc_retune(struct mmc_host *host)
 {
diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
index 992bf5397633..0787b3002481 100644
--- a/drivers/mmc/core/host.h
+++ b/drivers/mmc/core/host.h
@@ -17,8 +17,6 @@ void mmc_unregister_host_class(void);
 
 void mmc_retune_enable(struct mmc_host *host);
 void mmc_retune_disable(struct mmc_host *host);
-void mmc_retune_hold(struct mmc_host *host);
-void mmc_retune_release(struct mmc_host *host);
 int mmc_retune(struct mmc_host *host);
 
 #endif
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 63dc01257852..4c6d131cafc2 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -204,6 +204,9 @@ extern int mmc_flush_cache(struct mmc_card *);
 
 extern int mmc_detect_card_removed(struct mmc_host *host);
 
+extern void mmc_retune_hold(struct mmc_host *host);
+extern void mmc_retune_release(struct mmc_host *host);
+
 /**
  *	mmc_claim_host - exclusively claim a host
  *	@host: mmc host to claim
-- 
1.9.1

[PATCH RFC 37/46] mmc: block: Factor out mmc_blk_requeue()

[Adrian Hunter]

The same code is used in a couple of places.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/block.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 4bd431999a1f..b3daa7ffc7ec 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1317,6 +1317,13 @@ static int mmc_blk_issue_flush(struct mmc_queue *mq, struct request *req)
 	return ret ? 0 : 1;
 }
 
+static void mmc_blk_requeue(struct request_queue *q, struct request *req)
+{
+	spin_lock_irq(q->queue_lock);
+	blk_requeue_request(q, req);
+	spin_unlock_irq(q->queue_lock);
+}
+
 /*
  * Reformat current write as a reliable write, supporting
  * both legacy and the enhanced reliable write MMC cards.
@@ -1776,11 +1783,8 @@ static u8 mmc_blk_prep_packed_list(struct mmc_queue *mq, struct request *req)
 		reqs++;
 	} while (1);
 
-	if (put_back) {
-		spin_lock_irq(q->queue_lock);
-		blk_requeue_request(q, next);
-		spin_unlock_irq(q->queue_lock);
-	}
+	if (put_back)
+		mmc_blk_requeue(q, next);
 
 	if (reqs > 0) {
 		list_add(&req->queuelist, &mqrq->packed->list);
@@ -1968,9 +1972,7 @@ static void mmc_blk_revert_packed_req(struct mmc_queue *mq,
 		prq = list_entry_rq(packed->list.prev);
 		if (prq->queuelist.prev != &packed->list) {
 			list_del_init(&prq->queuelist);
-			spin_lock_irq(q->queue_lock);
-			blk_requeue_request(mq->queue, prq);
-			spin_unlock_irq(q->queue_lock);
+			mmc_blk_requeue(q, prq);
 		} else {
 			list_del_init(&prq->queuelist);
 		}
-- 
1.9.1

[PATCH RFC 38/46] mmc: block: Fix 4K native sector check

[Adrian Hunter]

The 4K native sector check does not allow for the 'do' loop nor the
variables used after the 'cmd_abort' label.

'brq' and 'req' get reassigned in the 'do' loop, so the check must not
assume what their values are. After the 'cmd_abort' label, 'mq_rq' and
'req' are used, but 'rqc' must be NULL otherwise it can be started again.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/block.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index b3daa7ffc7ec..b42318ce0ad7 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1985,11 +1985,11 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 {
 	struct mmc_blk_data *md = mq->data;
 	struct mmc_card *card = md->queue.card;
-	struct mmc_blk_request *brq = &mq->mqrq_cur->brq;
+	struct mmc_blk_request *brq;
 	int ret = 1, disable_multi = 0, retry = 0, type, retune_retry_done = 0;
 	enum mmc_blk_status status;
 	struct mmc_queue_req *mq_rq;
-	struct request *req = rqc;
+	struct request *req;
 	struct mmc_async_req *areq;
 	const u8 packed_nr = 2;
 	u8 reqs = 0;
@@ -2009,8 +2009,10 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 			if (mmc_large_sector(card) &&
 				!IS_ALIGNED(blk_rq_sectors(rqc), 8)) {
 				pr_err("%s: Transfer size is not 4KB sector size aligned\n",
-					req->rq_disk->disk_name);
+					rqc->rq_disk->disk_name);
 				mq_rq = mq->mqrq_cur;
+				req = rqc;
+				rqc = NULL;
 				goto cmd_abort;
 			}
 
-- 
1.9.1

[PATCH RFC 39/46] mmc: block: Use local var for mqrq_cur

[Adrian Hunter]

A subsequent patch will remove 'mq->mqrq_cur'. Prepare for that by
assigning it to a local variable.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/block.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index b42318ce0ad7..db28274a7624 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1988,6 +1988,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 	struct mmc_blk_request *brq;
 	int ret = 1, disable_multi = 0, retry = 0, type, retune_retry_done = 0;
 	enum mmc_blk_status status;
+	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
 	struct mmc_queue_req *mq_rq;
 	struct request *req;
 	struct mmc_async_req *areq;
@@ -2010,18 +2011,18 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 				!IS_ALIGNED(blk_rq_sectors(rqc), 8)) {
 				pr_err("%s: Transfer size is not 4KB sector size aligned\n",
 					rqc->rq_disk->disk_name);
-				mq_rq = mq->mqrq_cur;
+				mq_rq = mqrq_cur;
 				req = rqc;
 				rqc = NULL;
 				goto cmd_abort;
 			}
 
 			if (reqs >= packed_nr)
-				mmc_blk_packed_hdr_wrq_prep(mq->mqrq_cur,
+				mmc_blk_packed_hdr_wrq_prep(mqrq_cur,
 							    card, mq);
 			else
-				mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);
-			areq = &mq->mqrq_cur->mmc_active;
+				mmc_blk_rw_rq_prep(mqrq_cur, card, 0, mq);
+			areq = &mqrq_cur->mmc_active;
 		} else
 			areq = NULL;
 		areq = mmc_start_req(card->host, areq, (int *) &status);
@@ -2163,12 +2164,12 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 			/*
 			 * If current request is packed, it needs to put back.
 			 */
-			if (mmc_packed_cmd(mq->mqrq_cur->cmd_type))
-				mmc_blk_revert_packed_req(mq, mq->mqrq_cur);
+			if (mmc_packed_cmd(mqrq_cur->cmd_type))
+				mmc_blk_revert_packed_req(mq, mqrq_cur);
 
-			mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);
+			mmc_blk_rw_rq_prep(mqrq_cur, card, 0, mq);
 			mmc_start_req(card->host,
-				      &mq->mqrq_cur->mmc_active, NULL);
+				      &mqrq_cur->mmc_active, NULL);
 		}
 	}
 
-- 
1.9.1

[PATCH RFC 40/46] mmc: block: Pass mqrq to mmc_blk_prep_packed_list()

[Adrian Hunter]

A subsequent patch will remove 'mq->mqrq_cur'. Prepare for that by
passing mqrq to mmc_blk_prep_packed_list().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/block.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index db28274a7624..1cb823a4dc76 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1693,13 +1693,14 @@ static inline u8 mmc_calc_packed_hdr_segs(struct request_queue *q,
 	return nr_segs;
 }
 
-static u8 mmc_blk_prep_packed_list(struct mmc_queue *mq, struct request *req)
+static u8 mmc_blk_prep_packed_list(struct mmc_queue *mq,
+				   struct mmc_queue_req *mqrq)
 {
 	struct request_queue *q = mq->queue;
 	struct mmc_card *card = mq->card;
+	struct request *req = mqrq->req;
 	struct request *cur = req, *next = NULL;
 	struct mmc_blk_data *md = mq->data;
-	struct mmc_queue_req *mqrq = mq->mqrq_cur;
 	bool en_rel_wr = card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN;
 	unsigned int req_sectors = 0, phys_segments = 0;
 	unsigned int max_blk_count, max_phys_segs;
@@ -1998,8 +1999,8 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 	if (!rqc && !mq->mqrq_prev->req)
 		return 0;
 
-	if (rqc)
-		reqs = mmc_blk_prep_packed_list(mq, rqc);
+	if (mqrq_cur)
+		reqs = mmc_blk_prep_packed_list(mq, mqrq_cur);
 
 	do {
 		if (rqc) {
-- 
1.9.1

[PATCH RFC 41/46] mmc: block: Introduce queue semantics

[Adrian Hunter]

Change from viewing the requests in progress as 'current' and 'previous',
to viewing them as a queue. The current request is allocated to the first
free slot. The presence of incomplete requests is determined from the
count (mq->qcnt) of entries in the queue. Non-read-write requests (i.e.
discards and flushes) are not added to the queue at all and require no
special handling. Also no special handling is needed for the
MMC_BLK_NEW_REQUEST case.

As well as allowing an arbitrarily sized queue, the queue thread function
is significantly simpler.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/block.c | 40 +++++++++++++------------
 drivers/mmc/card/queue.c | 76 ++++++++++++++++++++++++++++++------------------
 drivers/mmc/card/queue.h | 10 +++++--
 3 files changed, 77 insertions(+), 49 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 1cb823a4dc76..215cfa359a3f 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1989,14 +1989,23 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 	struct mmc_blk_request *brq;
 	int ret = 1, disable_multi = 0, retry = 0, type, retune_retry_done = 0;
 	enum mmc_blk_status status;
-	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
+	struct mmc_queue_req *mqrq_cur = NULL;
 	struct mmc_queue_req *mq_rq;
 	struct request *req;
 	struct mmc_async_req *areq;
 	const u8 packed_nr = 2;
 	u8 reqs = 0;
 
-	if (!rqc && !mq->mqrq_prev->req)
+	if (rqc) {
+		mqrq_cur = mmc_queue_req_find(mq, rqc);
+		if (!mqrq_cur) {
+			WARN_ON(1);
+			mmc_blk_requeue(mq->queue, rqc);
+			rqc = NULL;
+		}
+	}
+
+	if (!mq->qcnt)
 		return 0;
 
 	if (mqrq_cur)
@@ -2027,11 +2036,8 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 		} else
 			areq = NULL;
 		areq = mmc_start_req(card->host, areq, (int *) &status);
-		if (!areq) {
-			if (status == MMC_BLK_NEW_REQUEST)
-				mq->flags |= MMC_QUEUE_NEW_REQUEST;
+		if (!areq)
 			return 0;
-		}
 
 		mq_rq = container_of(areq, struct mmc_queue_req, mmc_active);
 		brq = &mq_rq->brq;
@@ -2143,6 +2149,8 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 		}
 	} while (ret);
 
+	mmc_queue_req_free(mq, mq_rq);
+
 	return 1;
 
  cmd_abort:
@@ -2161,6 +2169,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 		if (mmc_card_removed(card)) {
 			rqc->cmd_flags |= REQ_QUIET;
 			blk_end_request_all(rqc, -EIO);
+			mmc_queue_req_free(mq, mqrq_cur);
 		} else {
 			/*
 			 * If current request is packed, it needs to put back.
@@ -2174,6 +2183,8 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 		}
 	}
 
+	mmc_queue_req_free(mq, mq_rq);
+
 	return 0;
 }
 
@@ -2184,7 +2195,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 	struct mmc_card *card = md->queue.card;
 	unsigned int cmd_flags = req ? req->cmd_flags : 0;
 
-	if (req && !mq->mqrq_prev->req)
+	if (req && !mq->qcnt)
 		/* claim host only for the first request */
 		mmc_get_card(card);
 
@@ -2197,10 +2208,9 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 		goto out;
 	}
 
-	mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
 	if (cmd_flags & REQ_DISCARD) {
 		/* complete ongoing async transfer before issuing discard */
-		if (card->host->areq)
+		if (mq->qcnt)
 			mmc_blk_issue_rw_rq(mq, NULL);
 		if (req->cmd_flags & REQ_SECURE)
 			ret = mmc_blk_issue_secdiscard_rq(mq, req);
@@ -2208,7 +2218,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 			ret = mmc_blk_issue_discard_rq(mq, req);
 	} else if (cmd_flags & REQ_FLUSH) {
 		/* complete ongoing async transfer before issuing flush */
-		if (card->host->areq)
+		if (mq->qcnt)
 			mmc_blk_issue_rw_rq(mq, NULL);
 		ret = mmc_blk_issue_flush(mq, req);
 	} else {
@@ -2216,14 +2226,8 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 	}
 
 out:
-	if ((!req && !(mq->flags & MMC_QUEUE_NEW_REQUEST)) ||
-	     (cmd_flags & MMC_REQ_SPECIAL_MASK))
-		/*
-		 * Release host when there are no more requests
-		 * and after special request(discard, flush) is done.
-		 * In case sepecial request, there is no reentry to
-		 * the 'mmc_blk_issue_rq' with 'mqrq_prev->req'.
-		 */
+	/* Release host when there are no more requests */
+	if (!mq->qcnt)
 		mmc_put_card(card);
 	return ret;
 }
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 4463d33094e4..4e134884a183 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -46,6 +46,35 @@ static int mmc_prep_request(struct request_queue *q, struct request *req)
 	return BLKPREP_OK;
 }
 
+struct mmc_queue_req *mmc_queue_req_find(struct mmc_queue *mq,
+					 struct request *req)
+{
+	struct mmc_queue_req *mqrq;
+	int i = ffz(mq->qslots);
+
+	if (i >= mq->qdepth)
+		return NULL;
+
+	mqrq = &mq->mqrq[i];
+	WARN_ON(mqrq->req || mq->qcnt >= mq->qdepth ||
+		test_bit(mqrq->task_id, &mq->qslots));
+	mqrq->req = req;
+	mq->qcnt += 1;
+	__set_bit(mqrq->task_id, &mq->qslots);
+
+	return mqrq;
+}
+
+void mmc_queue_req_free(struct mmc_queue *mq,
+			struct mmc_queue_req *mqrq)
+{
+	WARN_ON(!mqrq->req || mq->qcnt < 1 ||
+		!test_bit(mqrq->task_id, &mq->qslots));
+	mqrq->req = NULL;
+	mq->qcnt -= 1;
+	__clear_bit(mqrq->task_id, &mq->qslots);
+}
+
 static int mmc_queue_thread(void *d)
 {
 	struct mmc_queue *mq = d;
@@ -56,8 +85,7 @@ static int mmc_queue_thread(void *d)
 
 	down(&mq->thread_sem);
 	do {
-		struct request *req = NULL;
-		unsigned int cmd_flags = 0;
+		struct request *req;
 
 		spin_lock_irq(q->queue_lock);
 		set_current_state(TASK_INTERRUPTIBLE);
@@ -70,37 +98,17 @@ static int mmc_queue_thread(void *d)
 			 * Dispatch queue is empty so set flags for
 			 * mmc_request_fn() to wake us up.
 			 */
-			if (mq->mqrq_prev->req)
+			if (mq->qcnt)
 				cntx->is_waiting_last_req = true;
 			else
 				mq->asleep = true;
 		}
-		mq->mqrq_cur->req = req;
 		spin_unlock_irq(q->queue_lock);
 
-		if (req || mq->mqrq_prev->req) {
+		if (req || mq->qcnt) {
 			set_current_state(TASK_RUNNING);
-			cmd_flags = req ? req->cmd_flags : 0;
 			mq->issue_fn(mq, req);
 			cond_resched();
-			if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
-				mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
-				continue; /* fetch again */
-			}
-
-			/*
-			 * Current request becomes previous request
-			 * and vice versa.
-			 * In case of special requests, current request
-			 * has been finished. Do not assign it to previous
-			 * request.
-			 */
-			if (cmd_flags & MMC_REQ_SPECIAL_MASK)
-				mq->mqrq_cur->req = NULL;
-
-			mq->mqrq_prev->brq.mrq.data = NULL;
-			mq->mqrq_prev->req = NULL;
-			swap(mq->mqrq_prev, mq->mqrq_cur);
 		} else {
 			if (kthread_should_stop()) {
 				set_current_state(TASK_RUNNING);
@@ -183,6 +191,21 @@ static void mmc_queue_setup_discard(struct request_queue *q,
 		queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q);
 }
 
+static struct mmc_queue_req *mmc_queue_alloc_mqrqs(struct mmc_queue *mq,
+						   int qdepth)
+{
+	struct mmc_queue_req *mqrq;
+	int i;
+
+	mqrq = kcalloc(qdepth, sizeof(*mqrq), GFP_KERNEL);
+	if (mqrq) {
+		for (i = 0; i < mq->qdepth; i++)
+			mqrq[i].task_id = i;
+	}
+
+	return mqrq;
+}
+
 static bool mmc_queue_alloc_bounce_bufs(struct mmc_queue *mq,
 					unsigned int bouncesz)
 {
@@ -283,12 +306,9 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 		return -ENOMEM;
 
 	mq->qdepth = 2;
-	mq->mqrq = kcalloc(mq->qdepth, sizeof(struct mmc_queue_req),
-			   GFP_KERNEL);
+	mq->mqrq = mmc_queue_alloc_mqrqs(mq, mq->qdepth);
 	if (!mq->mqrq)
 		goto cleanup_queue;
-	mq->mqrq_cur = &mq->mqrq[0];
-	mq->mqrq_prev = &mq->mqrq[1];
 	mq->queue->queuedata = mq;
 
 	blk_queue_prep_rq(mq->queue, mmc_prep_request);
diff --git a/drivers/mmc/card/queue.h b/drivers/mmc/card/queue.h
index bb8dad281f72..1afd5dafd46d 100644
--- a/drivers/mmc/card/queue.h
+++ b/drivers/mmc/card/queue.h
@@ -42,6 +42,7 @@ struct mmc_queue_req {
 	struct mmc_async_req	mmc_active;
 	enum mmc_packed_type	cmd_type;
 	struct mmc_packed	*packed;
+	int			task_id;
 };
 
 struct mmc_queue {
@@ -50,16 +51,15 @@ struct mmc_queue {
 	struct semaphore	thread_sem;
 	unsigned int		flags;
 #define MMC_QUEUE_SUSPENDED	(1 << 0)
-#define MMC_QUEUE_NEW_REQUEST	(1 << 1)
 	bool			asleep;
 
 	int			(*issue_fn)(struct mmc_queue *, struct request *);
 	void			*data;
 	struct request_queue	*queue;
 	struct mmc_queue_req	*mqrq;
-	struct mmc_queue_req	*mqrq_cur;
-	struct mmc_queue_req	*mqrq_prev;
 	int			qdepth;
+	int			qcnt;
+	unsigned long		qslots;
 };
 
 extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *,
@@ -78,4 +78,8 @@ extern void mmc_packed_clean(struct mmc_queue *);
 
 extern int mmc_access_rpmb(struct mmc_queue *);
 
+extern struct mmc_queue_req *mmc_queue_req_find(struct mmc_queue *,
+						struct request *);
+extern void mmc_queue_req_free(struct mmc_queue *, struct mmc_queue_req *);
+
 #endif
-- 
1.9.1

[PATCH RFC 42/46] mmc: queue: Add a function to control wake-up on new requests

[Adrian Hunter]

Add a function to control wake-up on new requests. This will enable
Software Command Queuing to choose whether or not to queue new
requests immediately or wait for the current task to complete.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/queue.c | 16 ++++++++++++++++
 drivers/mmc/card/queue.h |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 4e134884a183..0781578fc8b6 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -94,6 +94,7 @@ static int mmc_queue_thread(void *d)
 		cntx->is_waiting_last_req = false;
 		cntx->is_new_req = false;
 		if (!req) {
+			mq->is_new_req = false;
 			/*
 			 * Dispatch queue is empty so set flags for
 			 * mmc_request_fn() to wake us up.
@@ -144,6 +145,8 @@ static void mmc_request_fn(struct request_queue *q)
 		return;
 	}
 
+	mq->is_new_req = true;
+
 	cntx = &mq->card->host->context_info;
 
 	if (cntx->is_waiting_last_req) {
@@ -155,6 +158,19 @@ static void mmc_request_fn(struct request_queue *q)
 		wake_up_process(mq->thread);
 }
 
+void mmc_queue_set_wake(struct mmc_queue *mq, bool wake_me)
+{
+	struct mmc_context_info *cntx = &mq->card->host->context_info;
+	struct request_queue *q = mq->queue;
+
+	if (cntx->is_waiting_last_req != wake_me) {
+		spin_lock_irq(q->queue_lock);
+		cntx->is_waiting_last_req = wake_me;
+		cntx->is_new_req = wake_me && mq->is_new_req;
+		spin_unlock_irq(q->queue_lock);
+	}
+}
+
 static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
 {
 	struct scatterlist *sg;
diff --git a/drivers/mmc/card/queue.h b/drivers/mmc/card/queue.h
index 1afd5dafd46d..a6d5b0f94662 100644
--- a/drivers/mmc/card/queue.h
+++ b/drivers/mmc/card/queue.h
@@ -52,6 +52,7 @@ struct mmc_queue {
 	unsigned int		flags;
 #define MMC_QUEUE_SUSPENDED	(1 << 0)
 	bool			asleep;
+	bool			is_new_req;
 
 	int			(*issue_fn)(struct mmc_queue *, struct request *);
 	void			*data;
@@ -81,5 +82,6 @@ extern int mmc_access_rpmb(struct mmc_queue *);
 extern struct mmc_queue_req *mmc_queue_req_find(struct mmc_queue *,
 						struct request *);
 extern void mmc_queue_req_free(struct mmc_queue *, struct mmc_queue_req *);
+extern void mmc_queue_set_wake(struct mmc_queue *, bool);
 
 #endif
-- 
1.9.1

[PATCH RFC 43/46] mmc: block: Add Software Command Queuing

[Adrian Hunter]

eMMC Command Queuing is a feature added in version 5.1.  The card maintains
a queue of up to 32 data transfers.  Commands CMD45/CMD45 are sent to queue
up transfers in advance, and then one of the transfers is selected to
"execute" by CMD46/CMD47 at which point data transfer actually begins.

The advantage of command queuing is that the card can prepare for transfers
in advance. That makes a big difference in the case of random reads because
the card can start reading into its cache in advance.

A v5.1 host controller can manage the command queue itself, but it is also
possible for software to manage the queue using an non-v5.1 host controller
- that is what Software Command Queuing is.

Refer to the JEDEC (http://www.jedec.org/) eMMC v5.1 Specification for more
information about Command Queuing.

Two important aspects of Command Queuing that affect the implementation
are:
 - only read/write requests are queued
 - the queue must be empty to send other commands, including re-tuning

To support Software Command Queuing a separate function is provided to
issue read/write requests (i.e. mmc_swcmdq_issue_rw_rq()) and the
mmc_blk_request structure amended to cater for additional commands CMD44
and CMD45. There is a separate function (mmc_swcmdq_prep()) to prepare the
needed commands, but transfers are started by mmc_start_req() like normal.

mmc_swcmdq_issue_rw_rq() enqueues the new request and then executes tasks
until the queue is empty or mmc_swcmdq_execute() asks for a new request.
This puts mmc_swcmdq_execute() in control of the decision whether to queue
more requests or wait for the active one.

Recovery is invoked if anything goes wrong. Recovery has 2 options:
 1. Discard the queue and re-queue all requests. If that fails, fall back
    to option 2.
 2. Reset and re-queue all requests. If that fails, error out all the
    requests.
In either case, re-tuning will be done if needed after the queue becomes
empty because re-tuning is released at that point.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/card/block.c | 595 ++++++++++++++++++++++++++++++++++++++++++++++-
 drivers/mmc/card/queue.c |   6 +-
 drivers/mmc/card/queue.h |  11 +-
 include/linux/mmc/card.h |   1 +
 4 files changed, 610 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 215cfa359a3f..b954516739be 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -110,6 +110,7 @@ struct mmc_blk_data {
 #define MMC_BLK_WRITE		BIT(1)
 #define MMC_BLK_DISCARD		BIT(2)
 #define MMC_BLK_SECDISCARD	BIT(3)
+#define MMC_BLK_SWCMDQ		BIT(4)
 
 	/*
 	 * Only set in main mmc_blk_data associated
@@ -1982,7 +1983,588 @@ static void mmc_blk_revert_packed_req(struct mmc_queue *mq,
 	mmc_blk_clear_packed(mq_rq);
 }
 
-static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
+static int mmc_swcmdq_err_check(struct mmc_card *card,
+				struct mmc_async_req *areq)
+{
+	struct mmc_queue_req *mqrq = container_of(areq, struct mmc_queue_req,
+						  mmc_active);
+	struct mmc_blk_request *brq = &mqrq->brq;
+	struct request *req = mqrq->req;
+	int err;
+
+	err = brq->data.error;
+	/* In the case of data errors, send stop */
+	if (err)
+		mmc_wait_for_cmd(card->host, &brq->stop, 0);
+	else
+		err = brq->cmd.error;
+
+	/* In the case of CRC errors when re-tuning is needed, retry */
+	if (err == -EILSEQ && card->host->need_retune)
+		return MMC_BLK_RETRY;
+
+	/* For other errors abort */
+	if (err)
+		return MMC_BLK_ABORT;
+
+	if (blk_rq_bytes(req) != brq->data.bytes_xfered)
+		return MMC_BLK_PARTIAL;
+
+	return MMC_BLK_SUCCESS;
+}
+
+static void mmc_swcmdq_prep(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
+{
+	struct mmc_blk_data *md = mq->data;
+	struct mmc_card *card = md->queue.card;
+	struct mmc_blk_request *brq = &mqrq->brq;
+	struct request *req = mqrq->req;
+	bool do_data_tag;
+
+	/*
+	 * Reliable writes are used to implement Forced Unit Access and
+	 * are supported only on MMCs.
+	 */
+	bool do_rel_wr = (req->cmd_flags & REQ_FUA) &&
+		(rq_data_dir(req) == WRITE) &&
+		(md->flags & MMC_BLK_REL_WR);
+
+	memset(brq, 0, sizeof(struct mmc_blk_request));
+	brq->mrq.cmd = &brq->cmd;
+	brq->mrq.data = &brq->data;
+	brq->mrq.cap_cmd_during_tfr = true;
+
+	if (rq_data_dir(req) == READ) {
+		brq->cmd.opcode = MMC_EXECUTE_READ_TASK;
+		brq->data.flags = MMC_DATA_READ;
+		brq->stop.flags = MMC_RSP_R1 | MMC_CMD_AC;
+	} else {
+		brq->cmd.opcode = MMC_EXECUTE_WRITE_TASK;
+		brq->data.flags = MMC_DATA_WRITE;
+		brq->stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
+	}
+	brq->cmd.arg = mqrq->task_id << 16;
+	brq->cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+
+	brq->data.blksz = 512;
+	brq->data.blocks = blk_rq_sectors(req);
+
+	brq->stop.opcode = MMC_STOP_TRANSMISSION;
+	brq->stop.arg = 0;
+
+	/*
+	 * The block layer doesn't support all sector count
+	 * restrictions, so we need to be prepared for too big
+	 * requests.
+	 */
+	if (brq->data.blocks > card->host->max_blk_count)
+		brq->data.blocks = card->host->max_blk_count;
+
+	if (do_rel_wr)
+		mmc_apply_rel_rw(brq, card, req);
+
+	/*
+	 * Data tag is used only during writing meta data to speed
+	 * up write and any subsequent read of this meta data
+	 */
+	do_data_tag = (card->ext_csd.data_tag_unit_size) &&
+		(req->cmd_flags & REQ_META) &&
+		(rq_data_dir(req) == WRITE) &&
+		((brq->data.blocks * brq->data.blksz) >=
+		 card->ext_csd.data_tag_unit_size);
+
+	brq->cmd44.opcode = MMC_QUE_TASK_PARAMS;
+	brq->cmd44.arg = brq->data.blocks |
+			 (do_rel_wr ? (1 << 31) : 0) |
+			 ((rq_data_dir(req) == READ) ? (1 << 30) : 0) |
+			 (do_data_tag ? (1 << 29) : 0) |
+			 mqrq->task_id << 16;
+	brq->cmd44.flags = MMC_RSP_R1 | MMC_CMD_AC;
+
+	brq->cmd45.opcode = MMC_QUE_TASK_ADDR;
+	brq->cmd45.arg = blk_rq_pos(req);
+
+	mmc_set_data_timeout(&brq->data, card);
+
+	brq->data.sg = mqrq->sg;
+	brq->data.sg_len = mmc_queue_map_sg(mq, mqrq);
+
+	/*
+	 * Adjust the sg list so it is the same size as the
+	 * request.
+	 */
+	if (brq->data.blocks != blk_rq_sectors(req)) {
+		int i, data_size = brq->data.blocks << 9;
+		struct scatterlist *sg;
+
+		for_each_sg(brq->data.sg, sg, brq->data.sg_len, i) {
+			data_size -= sg->length;
+			if (data_size <= 0) {
+				sg->length += data_size;
+				i++;
+				break;
+			}
+		}
+		brq->data.sg_len = i;
+	}
+
+	mqrq->mmc_active.mrq = &brq->mrq;
+	mqrq->mmc_active.err_check = mmc_swcmdq_err_check;
+
+	mmc_queue_bounce_pre(mqrq);
+}
+
+static int mmc_swcmdq_blk_err(struct mmc_card *card, int err)
+{
+	/* Re-try after CRC errors when re-tuning is needed */
+	if (err == -EILSEQ && card->host->need_retune)
+		return MMC_BLK_RETRY;
+
+	if (err)
+		return MMC_BLK_ABORT;
+
+	return 0;
+}
+
+#define SWCMDQ_ENQUEUE_ERR (	\
+	R1_OUT_OF_RANGE |	\
+	R1_ADDRESS_ERROR |	\
+	R1_BLOCK_LEN_ERROR |	\
+	R1_WP_VIOLATION |	\
+	R1_CC_ERROR |		\
+	R1_ERROR |		\
+	R1_COM_CRC_ERROR |	\
+	R1_ILLEGAL_COMMAND)
+
+static int __mmc_swcmdq_enqueue(struct mmc_queue *mq,
+				struct mmc_queue_req *mqrq)
+{
+	struct mmc_card *card = mq->card;
+	int err;
+
+	mmc_swcmdq_prep(mq, mqrq);
+
+	err = mmc_wait_for_cmd(card->host, &mqrq->brq.cmd44, 0);
+	if (err)
+		goto out;
+
+	err = mmc_wait_for_cmd(card->host, &mqrq->brq.cmd45, 0);
+	if (err)
+		goto out;
+
+	/*
+	 * Don't assume the task is queued if there are any error bits set in
+	 * the response.
+	 */
+	if (mqrq->brq.cmd45.resp[0] & SWCMDQ_ENQUEUE_ERR)
+		return MMC_BLK_ABORT;
+out:
+	return mmc_swcmdq_blk_err(card, err);
+}
+
+static int mmc_swcmdq_enqueue(struct mmc_queue *mq, struct request *req)
+{
+	struct mmc_queue_req *mqrq;
+
+	mqrq = mmc_queue_req_find(mq, req);
+	if (!mqrq) {
+		WARN_ON(1);
+		mmc_blk_requeue(mq->queue, req);
+		return 0;
+	}
+
+	/* Need to hold re-tuning so long as the queue is not empty */
+	if (mq->qcnt == 1)
+		mmc_retune_hold(mq->card->host);
+
+	return __mmc_swcmdq_enqueue(mq, mqrq);
+}
+
+static struct mmc_async_req *mmc_swcmdq_next(struct mmc_queue *mq)
+{
+	int i = __ffs(mq->qsr);
+
+	__clear_bit(i, &mq->qsr);
+
+	if (i >= mq->qdepth)
+		return NULL;
+
+	return &mq->mqrq[i].mmc_active;
+}
+
+static int mmc_get_qsr(struct mmc_card *card, u32 *qsr)
+{
+	struct mmc_command cmd = {0};
+	int err, retries = 3;
+
+	cmd.opcode = MMC_SEND_STATUS;
+	cmd.arg = card->rca << 16 | 1 << 15;
+	cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
+	err = mmc_wait_for_cmd(card->host, &cmd, retries);
+	if (err)
+		return err;
+
+	*qsr = cmd.resp[0];
+
+	return 0;
+}
+
+static int mmc_await_qsr(struct mmc_card *card, u32 *qsr)
+{
+	unsigned long timeout;
+	u32 status = 0;
+	int err;
+
+	timeout = jiffies + msecs_to_jiffies(10 * 1000);
+	while (!status) {
+		err = mmc_get_qsr(card, &status);
+		if (err)
+			return err;
+		if (time_after(jiffies, timeout)) {
+			pr_err("%s: Card stuck with queued tasks\n",
+			       mmc_hostname(card->host));
+			return -ETIMEDOUT;
+		}
+	}
+
+	*qsr = status;
+
+	return 0;
+}
+
+static int mmc_swcmdq_await_qsr(struct mmc_queue *mq, struct mmc_card *card,
+				bool wait)
+{
+	struct mmc_queue_req *mqrq;
+	u32 qsr;
+	int err;
+
+	if (wait)
+		err = mmc_await_qsr(card, &qsr);
+	else
+		err = mmc_get_qsr(card, &qsr);
+	if (err)
+		goto out_err;
+
+	mq->qsr = qsr;
+
+	if (card->host->areq) {
+		/*
+		 * The active request remains in the QSR until completed. Remove
+		 * it so that mq->qsr only contains ones that are ready but not
+		 * executed.
+		 */
+		mqrq = container_of(card->host->areq, struct mmc_queue_req,
+				    mmc_active);
+		__clear_bit(mqrq->task_id, &mq->qsr);
+	}
+
+	if (mq->qsr)
+		mq->qsr_err = false;
+out_err:
+	if (err) {
+		/* Don't repeatedly retry if no progress is made */
+		if (mq->qsr_err)
+			return MMC_BLK_ABORT;
+		mq->qsr_err = true;
+	}
+
+	return mmc_swcmdq_blk_err(card, err);
+}
+
+static int mmc_swcmdq_execute(struct mmc_queue *mq, bool flush, bool requeuing,
+			      bool new_req)
+{
+	struct mmc_card *card = mq->card;
+	struct mmc_async_req *next = NULL, *prev;
+	struct mmc_blk_request *brq;
+	struct mmc_queue_req *mqrq;
+	enum mmc_blk_status status;
+	struct request *req;
+	int active = card->host->areq ? 1 : 0;
+	int ret;
+
+	if (mq->prepared_areq) {
+		/*
+		 * A request that has been prepared before (i.e. passed to
+		 * mmc_start_req()) but not started because another new request
+		 * turned up.
+		 */
+		next = mq->prepared_areq;
+	} else if (requeuing) {
+		/* Just finish the active request */
+		next = NULL;
+	} else if (mq->qsr) {
+		/* Get the next task from the Queue Status Register */
+		next = mmc_swcmdq_next(mq);
+	} else if (mq->qcnt > active) {
+		/*
+		 * There are queued tasks so read the Queue Status Register to
+		 * see if any are ready. Wait for a ready task only if there is
+		 * no active request and no new request.
+		 */
+		ret = mmc_swcmdq_await_qsr(mq, card, !active && !new_req);
+		if (ret)
+			return ret;
+		if (mq->qsr)
+			next = mmc_swcmdq_next(mq);
+	}
+
+	if (next) {
+		/*
+		 * Don't wake for a new request when waiting for the active
+		 * request if there is another request ready to start.
+		 */
+		if (active)
+			mmc_queue_set_wake(mq, false);
+	} else {
+		if (!active)
+			return 0;
+		/*
+		 * Don't wake for a new request when flushing or the queue is
+		 * full.
+		 */
+		if (flush || mq->qcnt == mq->qdepth)
+			mmc_queue_set_wake(mq, false);
+		else
+			mmc_queue_set_wake(mq, true);
+	}
+
+	prev = mmc_start_req(card->host, next, (int *)&status);
+
+	if (status == MMC_BLK_NEW_REQUEST) {
+		mq->prepared_areq = next;
+		return status;
+	}
+
+	mq->prepared_areq = NULL;
+
+	if (!prev)
+		return 0;
+
+	mqrq = container_of(prev, struct mmc_queue_req, mmc_active);
+	brq = &mqrq->brq;
+	req = mqrq->req;
+
+	mmc_queue_bounce_post(mqrq);
+
+	switch (status) {
+	case MMC_BLK_SUCCESS:
+	case MMC_BLK_PARTIAL:
+	case MMC_BLK_SUCCESS_ERR:
+		mmc_blk_reset_success(mq->data, MMC_BLK_SWCMDQ);
+		ret = blk_end_request(req, 0, brq->data.bytes_xfered);
+		if (ret) {
+			if (!requeuing)
+				return __mmc_swcmdq_enqueue(mq, mqrq);
+			return 0;
+		}
+		break;
+	case MMC_BLK_NEW_REQUEST:
+		return status;
+	default:
+		if (mqrq->retry_cnt++) {
+			blk_end_request_all(req, -EIO);
+			break;
+		}
+		return status;
+	}
+
+	mmc_queue_req_free(mq, mqrq);
+
+	/* Release re-tuning when queue is empty */
+	if (!mq->qcnt)
+		mmc_retune_release(card->host);
+
+	return 0;
+}
+
+static int mmc_swcmdq_requeue_check(struct mmc_card *card,
+				    struct mmc_async_req *areq)
+{
+	int ret = mmc_swcmdq_err_check(card, areq);
+
+	/*
+	 * In the case of success, prevent mmc_start_req() from starting
+	 * another request by returning MMC_BLK_SUCCESS_ERR.
+	 */
+	return ret == MMC_BLK_SUCCESS ? MMC_BLK_SUCCESS_ERR : ret;
+}
+
+static int mmc_swcmdq_await_active(struct mmc_queue *mq)
+{
+	struct mmc_async_req *areq = mq->card->host->areq;
+	int err;
+
+	if (!areq)
+		return 0;
+
+	areq->err_check = mmc_swcmdq_requeue_check;
+
+	err = mmc_swcmdq_execute(mq, true, true, false);
+
+	/* The request will be requeued anyway, so ignore 'retry' */
+	if (err == MMC_BLK_RETRY)
+		err = 0;
+
+	return err;
+}
+
+static int mmc_swcmdq_discard_queue(struct mmc_queue *mq)
+{
+	struct mmc_card *card = mq->card;
+	struct mmc_command cmd = {0};
+	int err;
+
+	if (!mq->qcnt)
+		return 0;
+
+	cmd.opcode = MMC_CMDQ_TASK_MGMT;
+	cmd.arg = 1; /* Discard entire queue */
+	cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
+	/* This is for recovery and the response is not needed, so ignore CRC */
+	cmd.flags &= ~MMC_RSP_CRC;
+
+	err = mmc_wait_for_cmd(mq->card->host, &cmd, 0);
+
+	mq->qsr = 0;
+
+	/* Release re-tuning when queue is empty */
+	mmc_retune_release(card->host);
+
+	return err;
+}
+
+static int __mmc_swcmdq_requeue(struct mmc_queue *mq)
+{
+	unsigned long i, qslots = mq->qslots;
+	int err;
+
+	if (qslots)
+		mmc_retune_hold(mq->card->host);
+
+	while (qslots) {
+		i = __ffs(qslots);
+		err = __mmc_swcmdq_enqueue(mq, &mq->mqrq[i]);
+		if (err)
+			return err;
+		__clear_bit(i, &qslots);
+	}
+
+	return 0;
+}
+
+static void __mmc_swcmdq_error_out(struct mmc_queue *mq)
+{
+	unsigned long i, qslots = mq->qslots;
+	struct request *req;
+
+	if (qslots)
+		mmc_retune_release(mq->card->host);
+
+	while (qslots) {
+		i = __ffs(qslots);
+		req = mq->mqrq[i].req;
+		blk_end_request_cur(req, -EIO);
+		mq->mqrq[i].req = NULL;
+		__clear_bit(i, &qslots);
+	}
+
+	mq->qslots = 0;
+	mq->qcnt = 0;
+}
+
+static int mmc_swcmdq_requeue(struct mmc_queue *mq)
+{
+	int err;
+
+	/* Wait for active request */
+	err = mmc_swcmdq_await_active(mq);
+	if (err)
+		return err;
+
+	err = mmc_swcmdq_discard_queue(mq);
+	if (err)
+		return err;
+
+	return __mmc_swcmdq_requeue(mq);
+}
+
+static void mmc_swcmdq_reset(struct mmc_queue *mq)
+{
+	/* Wait for active request ignoring errors */
+	mmc_swcmdq_await_active(mq);
+
+	/* Ensure the queue is discarded */
+	mmc_swcmdq_discard_queue(mq);
+
+	/* Reset and requeue else error out all requests */
+	if (mmc_blk_reset(mq->data, mq->card->host, MMC_BLK_SWCMDQ) ||
+	    __mmc_swcmdq_requeue(mq))
+		__mmc_swcmdq_error_out(mq);
+}
+
+/*
+ * Recovery has 2 options:
+ * 1. Discard the queue and re-queue all requests. If that fails, fall back to
+ *    option 2.
+ * 2. Reset and re-queue all requests. If that fails, error out all the
+ *    requests.
+ * In either case, re-tuning will be done if needed after the queue becomes
+ * empty because re-tuning is released at that point.
+ */
+static void mmc_swcmdq_recovery(struct mmc_queue *mq, int err)
+{
+	switch (err) {
+	case MMC_BLK_RETRY:
+		err = mmc_swcmdq_requeue(mq);
+		if (!err)
+			break;
+		/* Fall through */
+	default:
+		mmc_swcmdq_reset(mq);
+	}
+}
+
+static int mmc_swcmdq_issue_rw_rq(struct mmc_queue *mq, struct request *req)
+{
+	struct mmc_context_info *cntx = &mq->card->host->context_info;
+	bool flush = !req && !cntx->is_waiting_last_req;
+	int err;
+
+	/* Enqueue new requests */
+	if (req) {
+		err = mmc_swcmdq_enqueue(mq, req);
+		if (err)
+			mmc_swcmdq_recovery(mq, err);
+	}
+
+	/*
+	 * Keep executing queued requests until the queue is empty or
+	 * mmc_swcmdq_execute() asks for new requests by returning
+	 * MMC_BLK_NEW_REQUEST.
+	 */
+	while (mq->qcnt) {
+		/*
+		 * Re-tuning can only be done when the queue is empty. Recovery
+		 * for MMC_BLK_RETRY will discard the queue and re-queue all
+		 * requests. At the point the queue is empty, re-tuning is
+		 * released and will be done automatically before the next
+		 * mmc_request.
+		 */
+		if (mq->card->host->need_retune)
+			mmc_swcmdq_recovery(mq, MMC_BLK_RETRY);
+		err = mmc_swcmdq_execute(mq, flush, false, !!req);
+		if (err == MMC_BLK_NEW_REQUEST)
+			return 0;
+		if (err)
+			mmc_swcmdq_recovery(mq, err);
+	}
+
+	return 0;
+}
+
+static int __mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 {
 	struct mmc_blk_data *md = mq->data;
 	struct mmc_card *card = md->queue.card;
@@ -2188,6 +2770,17 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 	return 0;
 }
 
+static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
+{
+	struct mmc_blk_data *md = mq->data;
+	struct mmc_card *card = md->queue.card;
+
+	if (card->ext_csd.cmdq_en)
+		return mmc_swcmdq_issue_rw_rq(mq, req);
+	else
+		return __mmc_blk_issue_rw_rq(mq, req);
+}
+
 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 {
 	int ret;
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 0781578fc8b6..10d67ec67944 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -61,6 +61,7 @@ struct mmc_queue_req *mmc_queue_req_find(struct mmc_queue *mq,
 	mqrq->req = req;
 	mq->qcnt += 1;
 	__set_bit(mqrq->task_id, &mq->qslots);
+	mqrq->retry_cnt = 0;
 
 	return mqrq;
 }
@@ -321,7 +322,10 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 	if (!mq->queue)
 		return -ENOMEM;
 
-	mq->qdepth = 2;
+	if (card->ext_csd.cmdq_en)
+		mq->qdepth = card->ext_csd.cmdq_depth;
+	else
+		mq->qdepth = 2;
 	mq->mqrq = mmc_queue_alloc_mqrqs(mq, mq->qdepth);
 	if (!mq->mqrq)
 		goto cleanup_queue;
diff --git a/drivers/mmc/card/queue.h b/drivers/mmc/card/queue.h
index a6d5b0f94662..72c47adf5f9f 100644
--- a/drivers/mmc/card/queue.h
+++ b/drivers/mmc/card/queue.h
@@ -8,9 +8,13 @@ struct task_struct;
 
 struct mmc_blk_request {
 	struct mmc_request	mrq;
-	struct mmc_command	sbc;
+	union {
+		struct mmc_command	sbc;
+		struct mmc_command	cmd44;
+	};
 	struct mmc_command	cmd;
 	struct mmc_command	stop;
+	struct mmc_command	cmd45;
 	struct mmc_data		data;
 	int			retune_retry_done;
 };
@@ -43,6 +47,7 @@ struct mmc_queue_req {
 	enum mmc_packed_type	cmd_type;
 	struct mmc_packed	*packed;
 	int			task_id;
+	unsigned int		retry_cnt;
 };
 
 struct mmc_queue {
@@ -61,6 +66,10 @@ struct mmc_queue {
 	int			qdepth;
 	int			qcnt;
 	unsigned long		qslots;
+	/* Following are defined for Software Command Queuing */
+	unsigned long		qsr;
+	struct mmc_async_req	*prepared_areq;
+	bool			qsr_err;
 };
 
 extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *,
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 2abcedc1e9e9..6e56ef23a94d 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -220,6 +220,7 @@ enum mmc_blk_status {
 	MMC_BLK_ECC_ERR,
 	MMC_BLK_NOMEDIUM,
 	MMC_BLK_NEW_REQUEST,
+	MMC_BLK_SUCCESS_ERR, /* Success but prevent starting another request */
 };
 
 /* The number of MMC physical partitions.  These consist of:
-- 
1.9.1

[PATCH RFC 44/46] mmc: mmc: Enable Software Command Queuing

[Adrian Hunter]

Enable the Command Queue if the host controller supports Software Command
Queuing. It is not compatible with Packed Commands, so do not enable that
at the same time.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/core/mmc.c   | 17 ++++++++++++++++-
 include/linux/mmc/host.h |  1 +
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 2e54daa237f6..cefa1ddca182 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1735,6 +1735,20 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 		}
 	}
 
+	/* Enable Command Queue if supported */
+	card->ext_csd.cmdq_en = false;
+	if (card->ext_csd.cmdq_support && host->caps & MMC_CAP_SWCMDQ) {
+		err = mmc_cmdq_enable(card);
+		if (err && err != -EBADMSG)
+			goto free_card;
+		if (err) {
+			pr_warn("%s: Enabling CMDQ failed\n",
+				mmc_hostname(card->host));
+			card->ext_csd.cmdq_support = false;
+			card->ext_csd.cmdq_depth = 0;
+			err = 0;
+		}
+	}
 	/*
 	 * In some cases (e.g. RPMB or mmc_test), the Command Queue must be
 	 * disabled for a time, so a flag is needed to indicate to re-enable the
@@ -1748,7 +1762,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	 */
 	if (card->ext_csd.max_packed_writes >= 3 &&
 	    card->ext_csd.max_packed_reads >= 5 &&
-	    host->caps2 & MMC_CAP2_PACKED_CMD) {
+	    host->caps2 & MMC_CAP2_PACKED_CMD &&
+	    !card->ext_csd.cmdq_en) {
 		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
 				EXT_CSD_EXP_EVENTS_CTRL,
 				EXT_CSD_PACKED_EVENT_EN,
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index c9ce8b0ae321..629a9bab6c4a 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -280,6 +280,7 @@ struct mmc_host {
 #define MMC_CAP_DRIVER_TYPE_A	(1 << 23)	/* Host supports Driver Type A */
 #define MMC_CAP_DRIVER_TYPE_C	(1 << 24)	/* Host supports Driver Type C */
 #define MMC_CAP_DRIVER_TYPE_D	(1 << 25)	/* Host supports Driver Type D */
+#define MMC_CAP_SWCMDQ		(1 << 28)	/* Software Command Queue */
 #define MMC_CAP_CMD_DURING_TFR	(1 << 29)	/* Commands during data transfer */
 #define MMC_CAP_CMD23		(1 << 30)	/* CMD23 supported. */
 #define MMC_CAP_HW_RESET	(1 << 31)	/* Hardware reset */
-- 
1.9.1

[PATCH RFC 45/46] mmc: sdhci-pci: Enable Software Command Queuing for some Intel controllers

[Adrian Hunter]

Set MMC_CAP_SWCMDQ for Intel BYT and related eMMC host controllers.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci-pci-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index 88f3958f014d..182da4148d44 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -356,7 +356,7 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot)
 {
 	slot->host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE |
 				 MMC_CAP_HW_RESET | MMC_CAP_1_8V_DDR |
-				 MMC_CAP_CMD_DURING_TFR |
+				 MMC_CAP_CMD_DURING_TFR | MMC_CAP_SWCMDQ |
 				 MMC_CAP_WAIT_WHILE_BUSY;
 	slot->host->mmc->caps2 |= MMC_CAP2_HC_ERASE_SZ;
 	slot->hw_reset = sdhci_pci_int_hw_reset;
-- 
1.9.1

[PATCH RFC 46/46] mmc: sdhci-acpi: Enable Software Command Queuing for some Intel controllers

[Adrian Hunter]

Set MMC_CAP_SWCMDQ for Intel BYT and related eMMC host controllers.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci-acpi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
index ec1b99f89d4a..2396eeb38345 100644
--- a/drivers/mmc/host/sdhci-acpi.c
+++ b/drivers/mmc/host/sdhci-acpi.c
@@ -273,7 +273,7 @@ static int sdhci_acpi_sd_probe_slot(struct platform_device *pdev,
 static const struct sdhci_acpi_slot sdhci_acpi_slot_int_emmc = {
 	.chip    = &sdhci_acpi_chip_int,
 	.caps    = MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE |
-		   MMC_CAP_HW_RESET | MMC_CAP_1_8V_DDR |
+		   MMC_CAP_HW_RESET | MMC_CAP_1_8V_DDR | MMC_CAP_SWCMDQ |
 		   MMC_CAP_CMD_DURING_TFR | MMC_CAP_WAIT_WHILE_BUSY,
 	.caps2   = MMC_CAP2_HC_ERASE_SZ,
 	.flags   = SDHCI_ACPI_RUNTIME_PM,
-- 
1.9.1