dmaengine: PTDMA: support polled mode

Commit Message

[e-mail] April 13, 2022, 11:37 a.m. UTC

From: Ilya Novikov <[e-mail]>

If the DMA_PREP_INTERRUPT flag is not provided, run in polled mode,
which significantly improves IOPS: more than twice on chunks < 4K.

Signed-off-by: Ilya Novikov <[e-mail]>
---
 drivers/dma/ptdma/ptdma-dev.c       | 36 +++++++++++++++--------------
 drivers/dma/ptdma/ptdma-dmaengine.c | 16 ++++++++++++-
 drivers/dma/ptdma/ptdma.h           | 13 +++++++++++
 3 files changed, 47 insertions(+), 18 deletions(-)

Comments

Vinod Koul April 20, 2022, 11:08 a.m. UTC | #1

On 13-04-22, 14:37, [e-mail] wrote:
> From: Ilya Novikov <[e-mail]>
> 
> If the DMA_PREP_INTERRUPT flag is not provided, run in polled mode,
> which significantly improves IOPS: more than twice on chunks < 4K.

Applied, thanks

Patch

diff --git a/drivers/dma/ptdma/ptdma-dev.c b/drivers/dma/ptdma/ptdma-dev.c
index daafea5bc35d..377da23012ac 100644
--- a/drivers/dma/ptdma/ptdma-dev.c
+++ b/drivers/dma/ptdma/ptdma-dev.c
@@ -100,6 +100,7 @@  int pt_core_perform_passthru(struct pt_cmd_queue *cmd_q,
 			     struct pt_passthru_engine *pt_engine)
 {
 	struct ptdma_desc desc;
+	struct pt_device *pt = container_of(cmd_q, struct pt_device, cmd_q);
 
 	cmd_q->cmd_error = 0;
 	cmd_q->total_pt_ops++;
@@ -111,17 +112,12 @@  int pt_core_perform_passthru(struct pt_cmd_queue *cmd_q,
 	desc.dst_lo = lower_32_bits(pt_engine->dst_dma);
 	desc.dw5.dst_hi = upper_32_bits(pt_engine->dst_dma);
 
-	return pt_core_execute_cmd(&desc, cmd_q);
-}
-
-static inline void pt_core_disable_queue_interrupts(struct pt_device *pt)
-{
-	iowrite32(0, pt->cmd_q.reg_control + 0x000C);
-}
+	if (cmd_q->int_en)
+		pt_core_enable_queue_interrupts(pt);
+	else
+		pt_core_disable_queue_interrupts(pt);
 
-static inline void pt_core_enable_queue_interrupts(struct pt_device *pt)
-{
-	iowrite32(SUPPORTED_INTERRUPTS, pt->cmd_q.reg_control + 0x000C);
+	return pt_core_execute_cmd(&desc, cmd_q);
 }
 
 static void pt_do_cmd_complete(unsigned long data)
@@ -144,14 +140,10 @@  static void pt_do_cmd_complete(unsigned long data)
 	cmd->pt_cmd_callback(cmd->data, cmd->ret);
 }
 
-static irqreturn_t pt_core_irq_handler(int irq, void *data)
+void pt_check_status_trans(struct pt_device *pt, struct pt_cmd_queue *cmd_q)
 {
-	struct pt_device *pt = data;
-	struct pt_cmd_queue *cmd_q = &pt->cmd_q;
 	u32 status;
 
-	pt_core_disable_queue_interrupts(pt);
-	pt->total_interrupts++;
 	status = ioread32(cmd_q->reg_control + 0x0010);
 	if (status) {
 		cmd_q->int_status = status;
@@ -162,11 +154,21 @@  static irqreturn_t pt_core_irq_handler(int irq, void *data)
 		if ((status & INT_ERROR) && !cmd_q->cmd_error)
 			cmd_q->cmd_error = CMD_Q_ERROR(cmd_q->q_status);
 
-		/* Acknowledge the interrupt */
+		/* Acknowledge the completion */
 		iowrite32(status, cmd_q->reg_control + 0x0010);
-		pt_core_enable_queue_interrupts(pt);
 		pt_do_cmd_complete((ulong)&pt->tdata);
 	}
+}
+
+static irqreturn_t pt_core_irq_handler(int irq, void *data)
+{
+	struct pt_device *pt = data;
+	struct pt_cmd_queue *cmd_q = &pt->cmd_q;
+
+	pt_core_disable_queue_interrupts(pt);
+	pt->total_interrupts++;
+	pt_check_status_trans(pt, cmd_q);
+	pt_core_enable_queue_interrupts(pt);
 	return IRQ_HANDLED;
 }
 
diff --git a/drivers/dma/ptdma/ptdma-dmaengine.c b/drivers/dma/ptdma/ptdma-dmaengine.c
index 91b93e8d9779..ea07cc42f4d0 100644
--- a/drivers/dma/ptdma/ptdma-dmaengine.c
+++ b/drivers/dma/ptdma/ptdma-dmaengine.c
@@ -171,6 +171,7 @@  static struct pt_dma_desc *pt_alloc_dma_desc(struct pt_dma_chan *chan,
 	vchan_tx_prep(&chan->vc, &desc->vd, flags);
 
 	desc->pt = chan->pt;
+	desc->pt->cmd_q.int_en = !!(flags & DMA_PREP_INTERRUPT);
 	desc->issued_to_hw = 0;
 	desc->status = DMA_IN_PROGRESS;
 
@@ -257,6 +258,17 @@  static void pt_issue_pending(struct dma_chan *dma_chan)
 		pt_cmd_callback(desc, 0);
 }
 
+enum dma_status
+pt_tx_status(struct dma_chan *c, dma_cookie_t cookie,
+		struct dma_tx_state *txstate)
+{
+	struct pt_device *pt = to_pt_chan(c)->pt;
+	struct pt_cmd_queue *cmd_q = &pt->cmd_q;
+
+	pt_check_status_trans(pt, cmd_q);
+	return dma_cookie_status(c, cookie, txstate);
+}
+
 static int pt_pause(struct dma_chan *dma_chan)
 {
 	struct pt_dma_chan *chan = to_pt_chan(dma_chan);
@@ -291,8 +303,10 @@  static int pt_terminate_all(struct dma_chan *dma_chan)
 {
 	struct pt_dma_chan *chan = to_pt_chan(dma_chan);
 	unsigned long flags;
+	struct pt_cmd_queue *cmd_q = &chan->pt->cmd_q;
 	LIST_HEAD(head);
 
+	iowrite32(SUPPORTED_INTERRUPTS, cmd_q->reg_control + 0x0010);
 	spin_lock_irqsave(&chan->vc.lock, flags);
 	vchan_get_all_descriptors(&chan->vc, &head);
 	spin_unlock_irqrestore(&chan->vc.lock, flags);
@@ -362,7 +376,7 @@  int pt_dmaengine_register(struct pt_device *pt)
 	dma_dev->device_prep_dma_memcpy = pt_prep_dma_memcpy;
 	dma_dev->device_prep_dma_interrupt = pt_prep_dma_interrupt;
 	dma_dev->device_issue_pending = pt_issue_pending;
-	dma_dev->device_tx_status = dma_cookie_status;
+	dma_dev->device_tx_status = pt_tx_status;
 	dma_dev->device_pause = pt_pause;
 	dma_dev->device_resume = pt_resume;
 	dma_dev->device_terminate_all = pt_terminate_all;
diff --git a/drivers/dma/ptdma/ptdma.h b/drivers/dma/ptdma/ptdma.h
index afbf192c9230..d093c43b7d13 100644
--- a/drivers/dma/ptdma/ptdma.h
+++ b/drivers/dma/ptdma/ptdma.h
@@ -206,6 +206,9 @@  struct pt_cmd_queue {
 	unsigned int active;
 	unsigned int suspended;
 
+	/* Interrupt flag */
+	bool int_en;
+
 	/* Register addresses for queue */
 	void __iomem *reg_control;
 	u32 qcontrol; /* Cached control register */
@@ -318,7 +321,17 @@  void pt_core_destroy(struct pt_device *pt);
 int pt_core_perform_passthru(struct pt_cmd_queue *cmd_q,
 			     struct pt_passthru_engine *pt_engine);
 
+void pt_check_status_trans(struct pt_device *pt, struct pt_cmd_queue *cmd_q);
 void pt_start_queue(struct pt_cmd_queue *cmd_q);
 void pt_stop_queue(struct pt_cmd_queue *cmd_q);
 
+static inline void pt_core_disable_queue_interrupts(struct pt_device *pt)
+{
+	iowrite32(0, pt->cmd_q.reg_control + 0x000C);
+}
+
+static inline void pt_core_enable_queue_interrupts(struct pt_device *pt)
+{
+	iowrite32(SUPPORTED_INTERRUPTS, pt->cmd_q.reg_control + 0x000C);
+}
 #endif