[PATCH v2 0/6] Fixup mtip32xx for scheduling

[PATCH v2 0/6] Fixup mtip32xx for scheduling

[Jens Axboe]

Round two of this patchset to cleanup. Changes since the first
posting:

- Mark internal commands as REQ_OP_DRV_IN. Doesn't really matter
  what the data direction is, the important bit is that we need
  to ensure the request is seen as a passthrough.

- Remove redundant active = 1 setting in mtip_commands_active().

- Utilize blk-mq timeout infrastructure, to avoid racing with
  cleanup.

-- 
Jens Axboe

[PATCH 1/2] mtip32xx: convert internal command issue to block IO path

[Jens Axboe]

The driver special cases certain things for command issue, depending
on whether it's an internal command or not. Make the internal commands
use the regular infrastructure for issuing IO.

Since this is an 8-group souped up AHCI variant, we have to deal
with NCQ vs non-queueable commands. Do this from the queue_rq
handler, by backing off unless the drive is idle.

Signed-off-by: Jens Axboe <axboe@fb.com>
---
 drivers/block/mtip32xx/mtip32xx.c | 101 +++++++++++++++++++++++++++-----------
 1 file changed, 71 insertions(+), 30 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index aee94f260725..cb2d93b3b8ec 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -195,7 +195,7 @@ static struct mtip_cmd *mtip_get_int_command(struct driver_data *dd)
 	if (mtip_check_surprise_removal(dd->pdev))
 		return NULL;
 
-	rq = blk_mq_alloc_request(dd->queue, 0, BLK_MQ_REQ_RESERVED);
+	rq = blk_mq_alloc_request(dd->queue, REQ_OP_DRV_IN, BLK_MQ_REQ_RESERVED);
 	if (IS_ERR(rq))
 		return NULL;
 
@@ -1088,6 +1088,13 @@ static int mtip_quiesce_io(struct mtip_port *port, unsigned long timeout)
 	return -EFAULT;
 }
 
+struct mtip_int_cmd {
+	int fis_len;
+	dma_addr_t buffer;
+	int buf_len;
+	u32 opts;
+};
+
 /*
  * Execute an internal command and wait for the completion.
  *
@@ -1114,10 +1121,16 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 					u32 opts,
 					unsigned long timeout)
 {
-	struct mtip_cmd_sg *command_sg;
 	DECLARE_COMPLETION_ONSTACK(wait);
 	struct mtip_cmd *int_cmd;
 	struct driver_data *dd = port->dd;
+	struct request *rq;
+	struct mtip_int_cmd icmd = {
+		.fis_len = fis_len,
+		.buffer = buffer,
+		.buf_len = buf_len,
+		.opts = opts
+	};
 	int rv = 0;
 	unsigned long start;
 
@@ -1132,6 +1145,8 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 		dbg_printk(MTIP_DRV_NAME "Unable to allocate tag for PIO cmd\n");
 		return -EFAULT;
 	}
+	rq = blk_mq_rq_from_pdu(int_cmd);
+	rq->end_io_data = &icmd;
 
 	set_bit(MTIP_PF_IC_ACTIVE_BIT, &port->flags);
 
@@ -1158,35 +1173,16 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 	/* Copy the command to the command table */
 	memcpy(int_cmd->command, fis, fis_len*4);
 
-	/* Populate the SG list */
-	int_cmd->command_header->opts =
-		 __force_bit2int cpu_to_le32(opts | fis_len);
-	if (buf_len) {
-		command_sg = int_cmd->command + AHCI_CMD_TBL_HDR_SZ;
-
-		command_sg->info =
-			__force_bit2int cpu_to_le32((buf_len-1) & 0x3FFFFF);
-		command_sg->dba	=
-			__force_bit2int cpu_to_le32(buffer & 0xFFFFFFFF);
-		command_sg->dba_upper =
-			__force_bit2int cpu_to_le32((buffer >> 16) >> 16);
-
-		int_cmd->command_header->opts |=
-			__force_bit2int cpu_to_le32((1 << 16));
-	}
-
-	/* Populate the command header */
-	int_cmd->command_header->byte_count = 0;
-
 	start = jiffies;
+	rq->timeout = timeout;
 
-	/* Issue the command to the hardware */
-	mtip_issue_non_ncq_command(port, MTIP_TAG_INTERNAL);
+	/* insert request and run queue */
+	blk_execute_rq_nowait(rq->q, NULL, rq, true, NULL);
+
+	wait_for_completion(&wait);
+	rv = int_cmd->status;
 
-	/* Wait for the command to complete or timeout. */
-	rv = wait_for_completion_interruptible_timeout(&wait,
-				msecs_to_jiffies(timeout));
-	if (rv <= 0) {
+	if (rv < 0) {
 		if (rv == -ERESTARTSYS) { /* interrupted */
 			dev_err(&dd->pdev->dev,
 				"Internal command [%02X] was interrupted after %u ms\n",
@@ -1217,7 +1213,6 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 		goto exec_ic_exit;
 	}
 
-	rv = 0;
 	if (readl(port->cmd_issue[MTIP_TAG_INTERNAL])
 			& (1 << MTIP_TAG_INTERNAL)) {
 		rv = -ENXIO;
@@ -3762,6 +3757,44 @@ static bool mtip_check_unal_depth(struct blk_mq_hw_ctx *hctx,
 	return false;
 }
 
+static int mtip_issue_reserved_cmd(struct blk_mq_hw_ctx *hctx,
+				   struct request *rq)
+{
+	struct driver_data *dd = hctx->queue->queuedata;
+	struct mtip_int_cmd *icmd = rq->end_io_data;
+	struct mtip_cmd *cmd = blk_mq_rq_to_pdu(rq);
+	struct mtip_cmd_sg *command_sg;
+
+	if (mtip_commands_active(dd->port))
+		return BLK_MQ_RQ_QUEUE_BUSY;
+
+	rq->end_io_data = NULL;
+
+	/* Populate the SG list */
+	cmd->command_header->opts =
+		 __force_bit2int cpu_to_le32(icmd->opts | icmd->fis_len);
+	if (icmd->buf_len) {
+		command_sg = cmd->command + AHCI_CMD_TBL_HDR_SZ;
+
+		command_sg->info =
+			__force_bit2int cpu_to_le32((icmd->buf_len-1) & 0x3FFFFF);
+		command_sg->dba	=
+			__force_bit2int cpu_to_le32(icmd->buffer & 0xFFFFFFFF);
+		command_sg->dba_upper =
+			__force_bit2int cpu_to_le32((icmd->buffer >> 16) >> 16);
+
+		cmd->command_header->opts |=
+			__force_bit2int cpu_to_le32((1 << 16));
+	}
+
+	/* Populate the command header */
+	cmd->command_header->byte_count = 0;
+
+	blk_mq_start_request(rq);
+	mtip_issue_non_ncq_command(dd->port, rq->tag);
+	return BLK_MQ_RQ_QUEUE_OK;
+}
+
 static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx,
 			 const struct blk_mq_queue_data *bd)
 {
@@ -3770,6 +3803,9 @@ static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx,
 
 	mtip_init_cmd_header(rq);
 
+	if (rq->rq_flags & RQF_RESERVED)
+		return mtip_issue_reserved_cmd(hctx, rq);
+
 	if (unlikely(mtip_check_unal_depth(hctx, rq)))
 		return BLK_MQ_RQ_QUEUE_BUSY;
 
@@ -3825,8 +3861,12 @@ static enum blk_eh_timer_return mtip_cmd_timeout(struct request *req,
 {
 	struct driver_data *dd = req->q->queuedata;
 
-	if (reserved)
+	if (reserved) {
+		struct mtip_cmd *cmd = blk_mq_rq_to_pdu(req);
+
+		cmd->status = -ETIME;
 		goto exit_handler;
+	}
 
 	if (test_bit(req->tag, dd->port->cmds_to_issue))
 		goto exit_handler;
@@ -4063,6 +4103,7 @@ static void mtip_no_dev_cleanup(struct request *rq, void *data, bool reserv)
 	} else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {
 
 		cmd = mtip_cmd_from_tag(dd, MTIP_TAG_INTERNAL);
+		cmd->status = -ENODEV;
 		if (cmd->comp_func)
 			cmd->comp_func(dd->port, MTIP_TAG_INTERNAL,
 					cmd, -ENODEV);
-- 
2.7.4

[PATCH 1/6] mtip32xx: get rid of 'atomic' argument to mtip_exec_internal_command()

[Jens Axboe]

All callers can safely block. Kill the atomic/block argument, and
remove the argument from all callers.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
 drivers/block/mtip32xx/mtip32xx.c | 148 +++++++++++---------------------------
 1 file changed, 43 insertions(+), 105 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 02804cc79d82..d81d797ee65d 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -609,11 +609,6 @@ static void mtip_completion(struct mtip_port *port,
 	complete(waiting);
 }
 
-static void mtip_null_completion(struct mtip_port *port,
-			    int tag, struct mtip_cmd *command, int status)
-{
-}
-
 static int mtip_read_log_page(struct mtip_port *port, u8 page, u16 *buffer,
 				dma_addr_t buffer_dma, unsigned int sectors);
 static int mtip_get_smart_attr(struct mtip_port *port, unsigned int id,
@@ -1117,7 +1112,6 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 					dma_addr_t buffer,
 					int buf_len,
 					u32 opts,
-					gfp_t atomic,
 					unsigned long timeout)
 {
 	struct mtip_cmd_sg *command_sg;
@@ -1146,30 +1140,22 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 
 	clear_bit(MTIP_PF_DM_ACTIVE_BIT, &port->flags);
 
-	if (atomic == GFP_KERNEL) {
-		if (fis->command != ATA_CMD_STANDBYNOW1) {
-			/* wait for io to complete if non atomic */
-			if (mtip_quiesce_io(port,
-				MTIP_QUIESCE_IO_TIMEOUT_MS, atomic) < 0) {
-				dev_warn(&dd->pdev->dev,
-					"Failed to quiesce IO\n");
-				mtip_put_int_command(dd, int_cmd);
-				clear_bit(MTIP_PF_IC_ACTIVE_BIT, &port->flags);
-				wake_up_interruptible(&port->svc_wait);
-				return -EBUSY;
-			}
+	if (fis->command != ATA_CMD_STANDBYNOW1) {
+		/* wait for io to complete if non atomic */
+		if (mtip_quiesce_io(port,
+			MTIP_QUIESCE_IO_TIMEOUT_MS, GFP_KERNEL) < 0) {
+			dev_warn(&dd->pdev->dev, "Failed to quiesce IO\n");
+			mtip_put_int_command(dd, int_cmd);
+			clear_bit(MTIP_PF_IC_ACTIVE_BIT, &port->flags);
+			wake_up_interruptible(&port->svc_wait);
+			return -EBUSY;
 		}
-
-		/* Set the completion function and data for the command. */
-		int_cmd->comp_data = &wait;
-		int_cmd->comp_func = mtip_completion;
-
-	} else {
-		/* Clear completion - we're going to poll */
-		int_cmd->comp_data = NULL;
-		int_cmd->comp_func = mtip_null_completion;
 	}
 
+	/* Set the completion function and data for the command. */
+	int_cmd->comp_data = &wait;
+	int_cmd->comp_func = mtip_completion;
+
 	/* Copy the command to the command table */
 	memcpy(int_cmd->command, fis, fis_len*4);
 
@@ -1198,81 +1184,41 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 	/* Issue the command to the hardware */
 	mtip_issue_non_ncq_command(port, MTIP_TAG_INTERNAL);
 
-	if (atomic == GFP_KERNEL) {
-		/* Wait for the command to complete or timeout. */
-		if ((rv = wait_for_completion_interruptible_timeout(
-				&wait,
-				msecs_to_jiffies(timeout))) <= 0) {
-
-			if (rv == -ERESTARTSYS) { /* interrupted */
-				dev_err(&dd->pdev->dev,
-					"Internal command [%02X] was interrupted after %u ms\n",
-					fis->command,
-					jiffies_to_msecs(jiffies - start));
-				rv = -EINTR;
-				goto exec_ic_exit;
-			} else if (rv == 0) /* timeout */
-				dev_err(&dd->pdev->dev,
-					"Internal command did not complete [%02X] within timeout of  %lu ms\n",
-					fis->command, timeout);
-			else
-				dev_err(&dd->pdev->dev,
-					"Internal command [%02X] wait returned code [%d] after %lu ms - unhandled\n",
-					fis->command, rv, timeout);
-
-			if (mtip_check_surprise_removal(dd->pdev) ||
-				test_bit(MTIP_DDF_REMOVE_PENDING_BIT,
-						&dd->dd_flag)) {
-				dev_err(&dd->pdev->dev,
-					"Internal command [%02X] wait returned due to SR\n",
-					fis->command);
-				rv = -ENXIO;
-				goto exec_ic_exit;
-			}
-			mtip_device_reset(dd); /* recover from timeout issue */
-			rv = -EAGAIN;
+	/* Wait for the command to complete or timeout. */
+	rv = wait_for_completion_interruptible_timeout(&wait,
+				msecs_to_jiffies(timeout));
+	if (rv <= 0) {
+		if (rv == -ERESTARTSYS) { /* interrupted */
+			dev_err(&dd->pdev->dev,
+				"Internal command [%02X] was interrupted after %u ms\n",
+				fis->command,
+				jiffies_to_msecs(jiffies - start));
+			rv = -EINTR;
 			goto exec_ic_exit;
-		}
-	} else {
-		u32 hba_stat, port_stat;
-
-		/* Spin for <timeout> checking if command still outstanding */
-		timeout = jiffies + msecs_to_jiffies(timeout);
-		while ((readl(port->cmd_issue[MTIP_TAG_INTERNAL])
-				& (1 << MTIP_TAG_INTERNAL))
-				&& time_before(jiffies, timeout)) {
-			if (mtip_check_surprise_removal(dd->pdev)) {
-				rv = -ENXIO;
-				goto exec_ic_exit;
-			}
-			if ((fis->command != ATA_CMD_STANDBYNOW1) &&
-				test_bit(MTIP_DDF_REMOVE_PENDING_BIT,
-						&dd->dd_flag)) {
-				rv = -ENXIO;
-				goto exec_ic_exit;
-			}
-			port_stat = readl(port->mmio + PORT_IRQ_STAT);
-			if (!port_stat)
-				continue;
+		} else if (rv == 0) /* timeout */
+			dev_err(&dd->pdev->dev,
+				"Internal command did not complete [%02X] within timeout of  %lu ms\n",
+				fis->command, timeout);
+		else
+			dev_err(&dd->pdev->dev,
+				"Internal command [%02X] wait returned code [%d] after %lu ms - unhandled\n",
+				fis->command, rv, timeout);
 
-			if (port_stat & PORT_IRQ_ERR) {
-				dev_err(&dd->pdev->dev,
-					"Internal command [%02X] failed\n",
-					fis->command);
-				mtip_device_reset(dd);
-				rv = -EIO;
-				goto exec_ic_exit;
-			} else {
-				writel(port_stat, port->mmio + PORT_IRQ_STAT);
-				hba_stat = readl(dd->mmio + HOST_IRQ_STAT);
-				if (hba_stat)
-					writel(hba_stat,
-						dd->mmio + HOST_IRQ_STAT);
-			}
-			break;
+		if (mtip_check_surprise_removal(dd->pdev) ||
+			test_bit(MTIP_DDF_REMOVE_PENDING_BIT,
+					&dd->dd_flag)) {
+			dev_err(&dd->pdev->dev,
+				"Internal command [%02X] wait returned due to SR\n",
+				fis->command);
+			rv = -ENXIO;
+			goto exec_ic_exit;
 		}
+		mtip_device_reset(dd); /* recover from timeout issue */
+		rv = -EAGAIN;
+		goto exec_ic_exit;
 	}
 
+	rv = 0;
 	if (readl(port->cmd_issue[MTIP_TAG_INTERNAL])
 			& (1 << MTIP_TAG_INTERNAL)) {
 		rv = -ENXIO;
@@ -1391,7 +1337,6 @@ static int mtip_get_identify(struct mtip_port *port, void __user *user_buffer)
 				port->identify_dma,
 				sizeof(u16) * ATA_ID_WORDS,
 				0,
-				GFP_KERNEL,
 				MTIP_INT_CMD_TIMEOUT_MS)
 				< 0) {
 		rv = -1;
@@ -1477,7 +1422,6 @@ static int mtip_standby_immediate(struct mtip_port *port)
 					0,
 					0,
 					0,
-					GFP_ATOMIC,
 					timeout);
 	dbg_printk(MTIP_DRV_NAME "Time taken to complete standby cmd: %d ms\n",
 			jiffies_to_msecs(jiffies - start));
@@ -1523,7 +1467,6 @@ static int mtip_read_log_page(struct mtip_port *port, u8 page, u16 *buffer,
 					buffer_dma,
 					sectors * ATA_SECT_SIZE,
 					0,
-					GFP_ATOMIC,
 					MTIP_INT_CMD_TIMEOUT_MS);
 }
 
@@ -1558,7 +1501,6 @@ static int mtip_get_smart_data(struct mtip_port *port, u8 *buffer,
 					buffer_dma,
 					ATA_SECT_SIZE,
 					0,
-					GFP_ATOMIC,
 					15000);
 }
 
@@ -1686,7 +1628,6 @@ static int mtip_send_trim(struct driver_data *dd, unsigned int lba,
 					dma_addr,
 					ATA_SECT_SIZE,
 					0,
-					GFP_KERNEL,
 					MTIP_TRIM_TIMEOUT_MS) < 0)
 		rv = -EIO;
 
@@ -1850,7 +1791,6 @@ static int exec_drive_task(struct mtip_port *port, u8 *command)
 				 0,
 				 0,
 				 0,
-				 GFP_KERNEL,
 				 to) < 0) {
 		return -1;
 	}
@@ -1946,7 +1886,6 @@ static int exec_drive_command(struct mtip_port *port, u8 *command,
 				 (xfer_sz ? dma_addr : 0),
 				 (xfer_sz ? ATA_SECT_SIZE * xfer_sz : 0),
 				 0,
-				 GFP_KERNEL,
 				 to)
 				 < 0) {
 		rv = -EFAULT;
@@ -2189,7 +2128,6 @@ static int exec_drive_taskfile(struct driver_data *dd,
 				 dma_buffer,
 				 transfer_size,
 				 0,
-				 GFP_KERNEL,
 				 timeout) < 0) {
 		err = -EIO;
 		goto abort;
-- 
2.7.4

[PATCH 2/2] Revert "mtip32xx: pass BLK_MQ_F_NO_SCHED"

[Jens Axboe]

This reverts commit 4981d04dd8f1ab19e2cce008da556d7f099b6e68.

The driver has been converted to using the proper infrastructure
for issuing internal commands. This means it's now safe to use with
the scheduling infrastruture, so we can now revert the change
that turned off scheduling for mtip32xx.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
 drivers/block/mtip32xx/mtip32xx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index cb2d93b3b8ec..5f39de02de83 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -3959,7 +3959,7 @@ static int mtip_block_initialize(struct driver_data *dd)
 	dd->tags.reserved_tags = 1;
 	dd->tags.cmd_size = sizeof(struct mtip_cmd);
 	dd->tags.numa_node = dd->numa_node;
-	dd->tags.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_NO_SCHED;
+	dd->tags.flags = BLK_MQ_F_SHOULD_MERGE;
 	dd->tags.driver_data = dd;
 	dd->tags.timeout = MTIP_NCQ_CMD_TIMEOUT_MS;
 
-- 
2.7.4

[PATCH 2/6] mtip32xx: kill atomic argument to mtip_quiesce_io()

[Jens Axboe]

All callers now pass in GFP_KERNEL, get rid of the argument.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
 drivers/block/mtip32xx/mtip32xx.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index d81d797ee65d..36f3d34f2156 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -1035,14 +1035,12 @@ static bool mtip_pause_ncq(struct mtip_port *port,
  *
  * @port    Pointer to port data structure
  * @timeout Max duration to wait (ms)
- * @atomic  gfp_t flag to indicate blockable context or not
  *
  * return value
  *	0	Success
  *	-EBUSY  Commands still active
  */
-static int mtip_quiesce_io(struct mtip_port *port, unsigned long timeout,
-								gfp_t atomic)
+static int mtip_quiesce_io(struct mtip_port *port, unsigned long timeout)
 {
 	unsigned long to;
 	unsigned int n;
@@ -1053,18 +1051,12 @@ static int mtip_quiesce_io(struct mtip_port *port, unsigned long timeout,
 	to = jiffies + msecs_to_jiffies(timeout);
 	do {
 		if (test_bit(MTIP_PF_SVC_THD_ACTIVE_BIT, &port->flags) &&
-			test_bit(MTIP_PF_ISSUE_CMDS_BIT, &port->flags) &&
-			atomic == GFP_KERNEL) {
+			test_bit(MTIP_PF_ISSUE_CMDS_BIT, &port->flags)) {
 			msleep(20);
 			continue; /* svc thd is actively issuing commands */
 		}
 
-		if (atomic == GFP_KERNEL)
-			msleep(100);
-		else {
-			cpu_relax();
-			udelay(100);
-		}
+		msleep(100);
 
 		if (mtip_check_surprise_removal(port->dd->pdev))
 			goto err_fault;
@@ -1142,8 +1134,7 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 
 	if (fis->command != ATA_CMD_STANDBYNOW1) {
 		/* wait for io to complete if non atomic */
-		if (mtip_quiesce_io(port,
-			MTIP_QUIESCE_IO_TIMEOUT_MS, GFP_KERNEL) < 0) {
+		if (mtip_quiesce_io(port, MTIP_QUIESCE_IO_TIMEOUT_MS) < 0) {
 			dev_warn(&dd->pdev->dev, "Failed to quiesce IO\n");
 			mtip_put_int_command(dd, int_cmd);
 			clear_bit(MTIP_PF_IC_ACTIVE_BIT, &port->flags);
@@ -4106,8 +4097,7 @@ static int mtip_block_remove(struct driver_data *dd)
 		 * Explicitly wait here for IOs to quiesce,
 		 * as mtip_standby_drive usually won't wait for IOs.
 		 */
-		if (!mtip_quiesce_io(dd->port, MTIP_QUIESCE_IO_TIMEOUT_MS,
-								GFP_KERNEL))
+		if (!mtip_quiesce_io(dd->port, MTIP_QUIESCE_IO_TIMEOUT_MS))
 			mtip_standby_drive(dd);
 	}
 	else
-- 
2.7.4

[PATCH 3/6] mtip32xx: abstract out "are any commands active" helper

[Jens Axboe]

This is a prep patch for backoff in ->queue_rq() for non-ncq commands.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
 drivers/block/mtip32xx/mtip32xx.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 36f3d34f2156..aee94f260725 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -1030,6 +1030,22 @@ static bool mtip_pause_ncq(struct mtip_port *port,
 	return false;
 }
 
+static bool mtip_commands_active(struct mtip_port *port)
+{
+	unsigned int active;
+	unsigned int n;
+
+	/*
+	 * Ignore s_active bit 0 of array element 0.
+	 * This bit will always be set
+	 */
+	active = readl(port->s_active[0]) & 0xFFFFFFFE;
+	for (n = 1; n < port->dd->slot_groups; n++)
+		active |= readl(port->s_active[n]);
+
+	return active != 0;
+}
+
 /*
  * Wait for port to quiesce
  *
@@ -1043,8 +1059,7 @@ static bool mtip_pause_ncq(struct mtip_port *port,
 static int mtip_quiesce_io(struct mtip_port *port, unsigned long timeout)
 {
 	unsigned long to;
-	unsigned int n;
-	unsigned int active = 1;
+	bool active = true;
 
 	blk_mq_stop_hw_queues(port->dd->queue);
 
@@ -1061,14 +1076,7 @@ static int mtip_quiesce_io(struct mtip_port *port, unsigned long timeout)
 		if (mtip_check_surprise_removal(port->dd->pdev))
 			goto err_fault;
 
-		/*
-		 * Ignore s_active bit 0 of array element 0.
-		 * This bit will always be set
-		 */
-		active = readl(port->s_active[0]) & 0xFFFFFFFE;
-		for (n = 1; n < port->dd->slot_groups; n++)
-			active |= readl(port->s_active[n]);
-
+		active = mtip_commands_active(port);
 		if (!active)
 			break;
 	} while (time_before(jiffies, to));
-- 
2.7.4

[PATCH 4/6] blk-mq: don't bypass scheduler for reserved requests

[Jens Axboe]

Instead of bypassing the scheduler for insertion of reserved requests,
we ensure that the request is marked as RQF_RESERVED so they driver
knows where it came from.

Usually we just use the tag to know if it's reserved or not,
but that only works when the request has a driver tag assigned.
Using RQF_RESERVED can be done independently of whether or not
scheduling is used.

Signed-off-by: Jens Axboe <axboe@fb.com>
---
 block/blk-mq-sched.c   | 8 +++-----
 block/blk-mq.c         | 3 +++
 include/linux/blkdev.h | 2 ++
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 8b361e192e8a..27c67465f856 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -82,11 +82,7 @@ struct request *blk_mq_sched_get_request(struct request_queue *q,
 	if (likely(!data->hctx))
 		data->hctx = blk_mq_map_queue(q, data->ctx->cpu);
 
-	/*
-	 * For a reserved tag, allocate a normal request since we might
-	 * have driver dependencies on the value of the internal tag.
-	 */
-	if (e && !(data->flags & BLK_MQ_REQ_RESERVED)) {
+	if (e) {
 		data->flags |= BLK_MQ_REQ_INTERNAL;
 
 		/*
@@ -104,6 +100,8 @@ struct request *blk_mq_sched_get_request(struct request_queue *q,
 	}
 
 	if (rq) {
+		if (data->flags & BLK_MQ_REQ_RESERVED)
+			rq->rq_flags |= RQF_RESERVED;
 		if (!op_is_flush(op)) {
 			rq->elv.icq = NULL;
 			if (e && e->type->icq_cache)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b75ef2392db7..0168b27469cb 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -268,6 +268,9 @@ struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data,
 			data->hctx->tags->rqs[rq->tag] = rq;
 		}
 
+		if (data->flags & BLK_MQ_REQ_RESERVED)
+			rq->rq_flags |= RQF_RESERVED;
+
 		blk_mq_rq_ctx_init(data->q, data->ctx, rq, op);
 		return rq;
 	}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index ba3884f26288..c246de5861dc 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -120,6 +120,8 @@ typedef __u32 __bitwise req_flags_t;
 /* Look at ->special_vec for the actual data payload instead of the
    bio chain. */
 #define RQF_SPECIAL_PAYLOAD	((__force req_flags_t)(1 << 18))
+/* Request came from the reserved tags/pool */
+#define RQF_RESERVED		((__force req_flags_t)(1 << 19))
 
 /* flags that prevent us from merging requests: */
 #define RQF_NOMERGE_FLAGS \
-- 
2.7.4

[PATCH 5/6] mtip32xx: convert internal command issue to block IO path

[Jens Axboe]

The driver special cases certain things for command issue, depending
on whether it's an internal command or not. Make the internal commands
use the regular infrastructure for issuing IO.

Since this is an 8-group souped up AHCI variant, we have to deal
with NCQ vs non-queueable commands. Do this from the queue_rq
handler, by backing off unless the drive is idle.

Signed-off-by: Jens Axboe <axboe@fb.com>
---
 drivers/block/mtip32xx/mtip32xx.c | 103 +++++++++++++++++++++++++++-----------
 1 file changed, 73 insertions(+), 30 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index aee94f260725..90f14f799527 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -195,7 +195,7 @@ static struct mtip_cmd *mtip_get_int_command(struct driver_data *dd)
 	if (mtip_check_surprise_removal(dd->pdev))
 		return NULL;
 
-	rq = blk_mq_alloc_request(dd->queue, 0, BLK_MQ_REQ_RESERVED);
+	rq = blk_mq_alloc_request(dd->queue, REQ_OP_DRV_IN, BLK_MQ_REQ_RESERVED);
 	if (IS_ERR(rq))
 		return NULL;
 
@@ -1088,6 +1088,13 @@ static int mtip_quiesce_io(struct mtip_port *port, unsigned long timeout)
 	return -EFAULT;
 }
 
+struct mtip_int_cmd {
+	int fis_len;
+	dma_addr_t buffer;
+	int buf_len;
+	u32 opts;
+};
+
 /*
  * Execute an internal command and wait for the completion.
  *
@@ -1114,10 +1121,16 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 					u32 opts,
 					unsigned long timeout)
 {
-	struct mtip_cmd_sg *command_sg;
 	DECLARE_COMPLETION_ONSTACK(wait);
 	struct mtip_cmd *int_cmd;
 	struct driver_data *dd = port->dd;
+	struct request *rq;
+	struct mtip_int_cmd icmd = {
+		.fis_len = fis_len,
+		.buffer = buffer,
+		.buf_len = buf_len,
+		.opts = opts
+	};
 	int rv = 0;
 	unsigned long start;
 
@@ -1132,6 +1145,8 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 		dbg_printk(MTIP_DRV_NAME "Unable to allocate tag for PIO cmd\n");
 		return -EFAULT;
 	}
+	rq = blk_mq_rq_from_pdu(int_cmd);
+	rq->end_io_data = &icmd;
 
 	set_bit(MTIP_PF_IC_ACTIVE_BIT, &port->flags);
 
@@ -1158,35 +1173,16 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 	/* Copy the command to the command table */
 	memcpy(int_cmd->command, fis, fis_len*4);
 
-	/* Populate the SG list */
-	int_cmd->command_header->opts =
-		 __force_bit2int cpu_to_le32(opts | fis_len);
-	if (buf_len) {
-		command_sg = int_cmd->command + AHCI_CMD_TBL_HDR_SZ;
-
-		command_sg->info =
-			__force_bit2int cpu_to_le32((buf_len-1) & 0x3FFFFF);
-		command_sg->dba	=
-			__force_bit2int cpu_to_le32(buffer & 0xFFFFFFFF);
-		command_sg->dba_upper =
-			__force_bit2int cpu_to_le32((buffer >> 16) >> 16);
-
-		int_cmd->command_header->opts |=
-			__force_bit2int cpu_to_le32((1 << 16));
-	}
-
-	/* Populate the command header */
-	int_cmd->command_header->byte_count = 0;
-
 	start = jiffies;
+	rq->timeout = timeout;
 
-	/* Issue the command to the hardware */
-	mtip_issue_non_ncq_command(port, MTIP_TAG_INTERNAL);
+	/* insert request and run queue */
+	blk_execute_rq_nowait(rq->q, NULL, rq, true, NULL);
+
+	wait_for_completion(&wait);
+	rv = int_cmd->status;
 
-	/* Wait for the command to complete or timeout. */
-	rv = wait_for_completion_interruptible_timeout(&wait,
-				msecs_to_jiffies(timeout));
-	if (rv <= 0) {
+	if (rv < 0) {
 		if (rv == -ERESTARTSYS) { /* interrupted */
 			dev_err(&dd->pdev->dev,
 				"Internal command [%02X] was interrupted after %u ms\n",
@@ -1217,7 +1213,6 @@ static int mtip_exec_internal_command(struct mtip_port *port,
 		goto exec_ic_exit;
 	}
 
-	rv = 0;
 	if (readl(port->cmd_issue[MTIP_TAG_INTERNAL])
 			& (1 << MTIP_TAG_INTERNAL)) {
 		rv = -ENXIO;
@@ -3762,6 +3757,44 @@ static bool mtip_check_unal_depth(struct blk_mq_hw_ctx *hctx,
 	return false;
 }
 
+static int mtip_issue_reserved_cmd(struct blk_mq_hw_ctx *hctx,
+				   struct request *rq)
+{
+	struct driver_data *dd = hctx->queue->queuedata;
+	struct mtip_int_cmd *icmd = rq->end_io_data;
+	struct mtip_cmd *cmd = blk_mq_rq_to_pdu(rq);
+	struct mtip_cmd_sg *command_sg;
+
+	if (mtip_commands_active(dd->port))
+		return BLK_MQ_RQ_QUEUE_BUSY;
+
+	rq->end_io_data = NULL;
+
+	/* Populate the SG list */
+	cmd->command_header->opts =
+		 __force_bit2int cpu_to_le32(icmd->opts | icmd->fis_len);
+	if (icmd->buf_len) {
+		command_sg = cmd->command + AHCI_CMD_TBL_HDR_SZ;
+
+		command_sg->info =
+			__force_bit2int cpu_to_le32((icmd->buf_len-1) & 0x3FFFFF);
+		command_sg->dba	=
+			__force_bit2int cpu_to_le32(icmd->buffer & 0xFFFFFFFF);
+		command_sg->dba_upper =
+			__force_bit2int cpu_to_le32((icmd->buffer >> 16) >> 16);
+
+		cmd->command_header->opts |=
+			__force_bit2int cpu_to_le32((1 << 16));
+	}
+
+	/* Populate the command header */
+	cmd->command_header->byte_count = 0;
+
+	blk_mq_start_request(rq);
+	mtip_issue_non_ncq_command(dd->port, rq->tag);
+	return BLK_MQ_RQ_QUEUE_OK;
+}
+
 static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx,
 			 const struct blk_mq_queue_data *bd)
 {
@@ -3770,6 +3803,9 @@ static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx,
 
 	mtip_init_cmd_header(rq);
 
+	if (rq->rq_flags & RQF_RESERVED)
+		return mtip_issue_reserved_cmd(hctx, rq);
+
 	if (unlikely(mtip_check_unal_depth(hctx, rq)))
 		return BLK_MQ_RQ_QUEUE_BUSY;
 
@@ -3825,8 +3861,14 @@ static enum blk_eh_timer_return mtip_cmd_timeout(struct request *req,
 {
 	struct driver_data *dd = req->q->queuedata;
 
-	if (reserved)
+	if (reserved) {
+		struct mtip_cmd *cmd = blk_mq_rq_to_pdu(req);
+
+		cmd->status = -ETIME;
+		if (cmd->comp_func)
+			cmd->comp_func(dd->port, MTIP_TAG_INTERNAL, cmd, -ETIME);
 		goto exit_handler;
+	}
 
 	if (test_bit(req->tag, dd->port->cmds_to_issue))
 		goto exit_handler;
@@ -4063,6 +4105,7 @@ static void mtip_no_dev_cleanup(struct request *rq, void *data, bool reserv)
 	} else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {
 
 		cmd = mtip_cmd_from_tag(dd, MTIP_TAG_INTERNAL);
+		cmd->status = -ENODEV;
 		if (cmd->comp_func)
 			cmd->comp_func(dd->port, MTIP_TAG_INTERNAL,
 					cmd, -ENODEV);
-- 
2.7.4

[PATCH 6/6] Revert "mtip32xx: pass BLK_MQ_F_NO_SCHED"

[Jens Axboe]

This reverts commit 4981d04dd8f1ab19e2cce008da556d7f099b6e68.

The driver has been converted to using the proper infrastructure
for issuing internal commands. This means it's now safe to use with
the scheduling infrastruture, so we can now revert the change
that turned off scheduling for mtip32xx.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
 drivers/block/mtip32xx/mtip32xx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 90f14f799527..15b9fcc2b89c 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -3961,7 +3961,7 @@ static int mtip_block_initialize(struct driver_data *dd)
 	dd->tags.reserved_tags = 1;
 	dd->tags.cmd_size = sizeof(struct mtip_cmd);
 	dd->tags.numa_node = dd->numa_node;
-	dd->tags.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_NO_SCHED;
+	dd->tags.flags = BLK_MQ_F_SHOULD_MERGE;
 	dd->tags.driver_data = dd;
 	dd->tags.timeout = MTIP_NCQ_CMD_TIMEOUT_MS;
 
-- 
2.7.4

Re: [PATCH v2 0/6] Fixup mtip32xx for scheduling

[Christoph Hellwig]

On Fri, Apr 28, 2017 at 08:01:49AM -0600, Jens Axboe wrote:
> Round two of this patchset to cleanup. Changes since the first
> posting:

I got two mixed series in my inbox, one with two patches and one with
6.  The two patch one doesn't seem to have a cover letter.

> 
> - Mark internal commands as REQ_OP_DRV_IN. Doesn't really matter
>   what the data direction is, the important bit is that we need
>   to ensure the request is seen as a passthrough.

Yes, I think that's the right thing to do.  I'll review the details.

> - Utilize blk-mq timeout infrastructure, to avoid racing with
>   cleanup.

Nice.

Re: [PATCH v2 0/6] Fixup mtip32xx for scheduling

[Jens Axboe]

On 04/28/2017 08:10 AM, Christoph Hellwig wrote:
> On Fri, Apr 28, 2017 at 08:01:49AM -0600, Jens Axboe wrote:
>> Round two of this patchset to cleanup. Changes since the first
>> posting:
> 
> I got two mixed series in my inbox, one with two patches and one with
> 6.  The two patch one doesn't seem to have a cover letter.

Hmm, I seem to get both series in full over the mailing. Perhaps
it'll show up later? Isn't it the cover letter you are replying
to?

Only patch #5 has changed since the last posting, the others just
collected reviews/acks.

-- 
Jens Axboe

Re: [PATCH v2 0/6] Fixup mtip32xx for scheduling

[Christoph Hellwig]

On Fri, Apr 28, 2017 at 08:13:56AM -0600, Jens Axboe wrote:
> On 04/28/2017 08:10 AM, Christoph Hellwig wrote:
> > On Fri, Apr 28, 2017 at 08:01:49AM -0600, Jens Axboe wrote:
> >> Round two of this patchset to cleanup. Changes since the first
> >> posting:
> > 
> > I got two mixed series in my inbox, one with two patches and one with
> > 6.  The two patch one doesn't seem to have a cover letter.
> 
> Hmm, I seem to get both series in full over the mailing. Perhaps
> it'll show up later? Isn't it the cover letter you are replying
> to?

That's the 0/6 cover letter, I didn't get a 0/2 one both here and
on my linux-block subsription (which uses a different mail server)

Re: [PATCH v2 0/6] Fixup mtip32xx for scheduling

[Jens Axboe]

On 04/28/2017 08:14 AM, Christoph Hellwig wrote:
> On Fri, Apr 28, 2017 at 08:13:56AM -0600, Jens Axboe wrote:
>> On 04/28/2017 08:10 AM, Christoph Hellwig wrote:
>>> On Fri, Apr 28, 2017 at 08:01:49AM -0600, Jens Axboe wrote:
>>>> Round two of this patchset to cleanup. Changes since the first
>>>> posting:
>>>
>>> I got two mixed series in my inbox, one with two patches and one with
>>> 6.  The two patch one doesn't seem to have a cover letter.
>>
>> Hmm, I seem to get both series in full over the mailing. Perhaps
>> it'll show up later? Isn't it the cover letter you are replying
>> to?
> 
> That's the 0/6 cover letter, I didn't get a 0/2 one both here and
> on my linux-block subsription (which uses a different mail server)

Ah. There is no 0/2 cover letter, I resent the full series (just with
v2 in the 0/6 line) with after having made the changes.


-- 
Jens Axboe