[PATCH v4 08/24] dmaengine: dw-edma: Prepare LL progress event handling

A later patch records each observed LL event (STOP or PROGRESS) together
with the LLP sample taken in the same interrupt-handler pass. Serializing
that capture with a channel restart needs to know whether interrupt status
is shared per channel or per direction. It also needs a provider operation
to clear stale LL interrupt status before a channel restart. Add both.

Centralize runtime request updates in dw_edma_set_request(). A later
patch uses it to cancel a pending LL recheck when STOP or PAUSE changes
the channel policy. Rename the existing workqueue event bits to
distinguish them from provider IRQ events.

No functional change.

Signed-off-by: Koichiro Den <[email protected]>
---
Changes in v4:
  - Explain that the LL event and LLP sample are recorded in the same
    interrupt-handler pass. (Frank)

 drivers/dma/dw-edma/dw-edma-core.c    | 35 ++++++++++++++++-----------
 drivers/dma/dw-edma/dw-edma-core.h    | 12 +++++++++
 drivers/dma/dw-edma/dw-edma-v0-core.c |  2 ++
 drivers/dma/dw-edma/dw-hdma-v0-core.c |  2 ++
 4 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index c036510dabcb..b84aed59bf77 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -30,9 +30,9 @@ struct dw_edma_desc *vd2dw_edma_desc(struct virt_dma_desc *vd)
 	return container_of(vd, struct dw_edma_desc, vd);
 }
 
-enum dw_edma_irq_event {
-	DW_EDMA_IRQ_DONE	= BIT(0),
-	DW_EDMA_IRQ_ABORT	= BIT(1),
+enum dw_edma_deferred_event {
+	DW_EDMA_DEFERRED_DONE	= BIT(0),
+	DW_EDMA_DEFERRED_ABORT	= BIT(1),
 };
 
 static inline
@@ -73,6 +73,13 @@ static void vchan_free_desc(struct virt_dma_desc *vdesc)
 	kfree(vd2dw_edma_desc(vdesc));
 }
 
+/* Must be called with vc.lock held. */
+static void
+dw_edma_set_request(struct dw_edma_chan *chan, enum dw_edma_request request)
+{
+	chan->request = request;
+}
+
 static void dw_hdma_set_callback_result(struct virt_dma_desc *vd,
 					enum dmaengine_tx_result result)
 {
@@ -243,7 +250,7 @@ static void dw_edma_finish_termination(struct dw_edma_chan *chan)
 	if (!chan->non_ll && dw_edma_ll_pending(chan))
 		dw_edma_core_reset_ll(chan);
 
-	chan->request = EDMA_REQ_NONE;
+	dw_edma_set_request(chan, EDMA_REQ_NONE);
 	chan->status = EDMA_ST_IDLE;
 }
 
@@ -360,7 +367,7 @@ static int dw_edma_device_pause(struct dma_chan *dchan)
 	else if (chan->request != EDMA_REQ_NONE)
 		err = -EPERM;
 	else
-		chan->request = EDMA_REQ_PAUSE;
+		dw_edma_set_request(chan, EDMA_REQ_PAUSE);
 
 	return err;
 }
@@ -410,10 +417,10 @@ static int dw_edma_device_terminate_all(struct dma_chan *dchan)
 	} else if (chan->request > EDMA_REQ_PAUSE) {
 		err = -EPERM;
 	} else {
-		chan->request = EDMA_REQ_STOP;
+		dw_edma_set_request(chan, EDMA_REQ_STOP);
 	}
 	if (chan->status == EDMA_ST_IDLE)
-		chan->request = EDMA_REQ_NONE;
+		dw_edma_set_request(chan, EDMA_REQ_NONE);
 
 	return err;
 }
@@ -724,7 +731,7 @@ static void dw_edma_done_interrupt(struct dw_edma_chan *chan)
 		}
 
 		if (chan->request == EDMA_REQ_PAUSE) {
-			chan->request = EDMA_REQ_NONE;
+			dw_edma_set_request(chan, EDMA_REQ_NONE);
 			chan->status = EDMA_ST_PAUSE;
 			break;
 		}
@@ -764,7 +771,7 @@ static void dw_edma_abort_interrupt(struct dw_edma_chan *chan)
 	}
 	if (!chan->non_ll)
 		dw_edma_core_reset_ll(chan);
-	chan->request = EDMA_REQ_NONE;
+	dw_edma_set_request(chan, EDMA_REQ_NONE);
 	chan->status = EDMA_ST_IDLE;
 	spin_unlock_irqrestore(&chan->vc.lock, flags);
 }
@@ -778,15 +785,15 @@ static void dw_edma_irq_work(struct work_struct *work)
 	do {
 		events = atomic_xchg(&chan->irq_pending, 0);
 
-		if (events & DW_EDMA_IRQ_DONE)
+		if (events & DW_EDMA_DEFERRED_DONE)
 			dw_edma_done_interrupt(chan);
-		if (events & DW_EDMA_IRQ_ABORT)
+		if (events & DW_EDMA_DEFERRED_ABORT)
 			dw_edma_abort_interrupt(chan);
 	} while (atomic_read(&chan->irq_pending));
 }
 
 static void dw_edma_queue_irq_work(struct dw_edma_chan *chan,
-				   enum dw_edma_irq_event event)
+				   enum dw_edma_deferred_event event)
 {
 	atomic_or(event, &chan->irq_pending);
 	queue_work(chan->dw->wq, &chan->irq_work);
@@ -794,12 +801,12 @@ static void dw_edma_queue_irq_work(struct dw_edma_chan *chan,
 
 static void dw_edma_done_interrupt_deferred(struct dw_edma_chan *chan)
 {
-	dw_edma_queue_irq_work(chan, DW_EDMA_IRQ_DONE);
+	dw_edma_queue_irq_work(chan, DW_EDMA_DEFERRED_DONE);
 }
 
 static void dw_edma_abort_interrupt_deferred(struct dw_edma_chan *chan)
 {
-	dw_edma_queue_irq_work(chan, DW_EDMA_IRQ_ABORT);
+	dw_edma_queue_irq_work(chan, DW_EDMA_DEFERRED_ABORT);
 }
 
 static void dw_edma_emul_irq_ack(struct irq_data *d)
diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
index 761a5ab4bbb5..95bd4bf47ea2 100644
--- a/drivers/dma/dw-edma/dw-edma-core.h
+++ b/drivers/dma/dw-edma/dw-edma-core.h
@@ -41,6 +41,11 @@ enum dw_edma_xfer_type {
 	EDMA_XFER_INTERLEAVED
 };
 
+enum dw_edma_event_scope {
+	DW_EDMA_EVENT_PER_CHAN,
+	DW_EDMA_EVENT_PER_DIR,
+};
+
 struct dw_edma_chan;
 struct dw_edma_chunk;
 
@@ -155,6 +160,7 @@ struct dw_edma_core_ops {
 	int (*ch_quiesce)(struct dw_edma_chan *chan);
 	u16 (*ch_count)(struct dw_edma *dw, enum dw_edma_dir dir);
 	enum dma_status (*ch_status)(struct dw_edma_chan *chan);
+	enum dw_edma_event_scope event_scope;
 	irqreturn_t (*handle_int)(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir,
 				  dw_edma_handler_t done, dw_edma_handler_t abort);
 	void (*non_ll_start)(struct dw_edma_chan *chan, struct dw_edma_burst *child);
@@ -163,6 +169,7 @@ struct dw_edma_core_ops {
 	void (*ll_link)(struct dw_edma_chan *chan, u32 idx, bool cb, u64 addr);
 	void (*ll_clear)(struct dw_edma_chan *chan, u32 idx);
 	int (*ll_cur_idx)(struct dw_edma_chan *chan);
+	void (*ll_irq_clear)(struct dw_edma_chan *chan);
 	void (*ch_doorbell)(struct dw_edma_chan *chan);
 	void (*ch_enable)(struct dw_edma_chan *chan);
 	void (*ch_config)(struct dw_edma_chan *chan);
@@ -284,6 +291,11 @@ static inline void dw_edma_core_ll_clear(struct dw_edma_chan *chan, u32 idx)
 	chan->dw->core->ll_clear(chan, idx);
 }
 
+static inline void dw_edma_core_ll_irq_clear(struct dw_edma_chan *chan)
+{
+	chan->dw->core->ll_irq_clear(chan);
+}
+
 static inline void dw_edma_core_ch_doorbell(struct dw_edma_chan *chan)
 {
 	chan->dw->core->ch_doorbell(chan);
diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
index 7ca4b6823ece..27c57f755d83 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-core.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-core.c
@@ -680,11 +680,13 @@ static const struct dw_edma_core_ops dw_edma_v0_core = {
 	.ch_quiesce = dw_edma_v0_core_ch_quiesce,
 	.ch_count = dw_edma_v0_core_ch_count,
 	.ch_status = dw_edma_v0_core_ch_status,
+	.event_scope = DW_EDMA_EVENT_PER_DIR,
 	.handle_int = dw_edma_v0_core_handle_int,
 	.ll_data = dw_edma_v0_core_ll_data,
 	.ll_link = dw_edma_v0_core_ll_link,
 	.ll_clear = dw_edma_v0_core_ll_clear,
 	.ll_cur_idx = dw_edma_v0_core_ll_cur_idx,
+	.ll_irq_clear = dw_edma_v0_core_clear_done_int,
 	.ch_doorbell = dw_edma_v0_core_ch_doorbell,
 	.ch_enable = dw_edma_v0_core_ch_enable,
 	.ch_config = dw_edma_v0_core_ch_config,
diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c
index 67a3a7778280..c8b9f6c42494 100644
--- a/drivers/dma/dw-edma/dw-hdma-v0-core.c
+++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c
@@ -435,12 +435,14 @@ static const struct dw_edma_core_ops dw_hdma_v0_core = {
 	.ch_quiesce = dw_hdma_v0_core_ch_quiesce,
 	.ch_count = dw_hdma_v0_core_ch_count,
 	.ch_status = dw_hdma_v0_core_ch_status,
+	.event_scope = DW_EDMA_EVENT_PER_CHAN,
 	.handle_int = dw_hdma_v0_core_handle_int,
 	.non_ll_start = dw_hdma_v0_core_non_ll_start,
 	.ll_data = dw_hdma_v0_core_ll_data,
 	.ll_link = dw_hdma_v0_core_ll_link,
 	.ll_clear = dw_hdma_v0_core_ll_clear,
 	.ll_cur_idx = dw_hdma_v0_core_ll_cur_idx,
+	.ll_irq_clear = dw_hdma_v0_core_clear_done_int,
 	.ch_doorbell = dw_hdma_v0_core_ch_doorbell,
 	.ch_enable = dw_hdma_v0_core_ch_enable,
 	.ch_config = dw_hdma_v0_core_ch_config,
-- 
2.51.0