[PATCH V5 01/10] Documentation: DT: qcom_hidma: update binding for MSI

[PATCH V5 01/10] Documentation: DT: qcom_hidma: update binding for MSI

[Sinan Kaya]

Adding a new binding for qcom,hidma-1.1 to distinguish HW supporting
MSI interrupts from the older revision.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt b/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt
index fd5618b..2c5e4b8 100644
--- a/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt
+++ b/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt
@@ -47,12 +47,18 @@ When the OS is not in control of the management interface (i.e. it's a guest),
 the channel nodes appear on their own, not under a management node.
 
 Required properties:
-- compatible: must contain "qcom,hidma-1.0"
+- compatible: must contain "qcom,hidma-1.0" for initial HW or "qcom,hidma-1.1"
+for MSI capable HW.
 - reg: Addresses for the transfer and event channel
 - interrupts: Should contain the event interrupt
 - desc-count: Number of asynchronous requests this channel can handle
 - iommus: required a iommu node
 
+Optional properties for MSI:
+- msi-parent : See the generic MSI binding described in
+ devicetree/bindings/interrupt-controller/msi.txt for a description of the
+ msi-parent property.
+
 Example:
 
 Hypervisor OS configuration:
-- 
1.9.1

Re: [PATCH V5 01/10] Documentation: DT: qcom_hidma: update binding for MSI

[Rob Herring]

On Fri, Oct 07, 2016 at 01:25:06AM -0400, Sinan Kaya wrote:
> Adding a new binding for qcom,hidma-1.1 to distinguish HW supporting
> MSI interrupts from the older revision.
> 
> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> ---
>  Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)

Acked-by: Rob Herring <robh@kernel.org>

[PATCH V5 02/10] Documentation: DT: qcom_hidma: correct spelling mistakes

[Sinan Kaya]

Fix the spelling mistakes and extra and statements in the sentences.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt b/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt
index 2c5e4b8..55492c2 100644
--- a/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt
+++ b/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt
@@ -5,13 +5,13 @@ memcpy and memset capabilities. It has been designed for virtualized
 environments.
 
 Each HIDMA HW instance consists of multiple DMA channels. These channels
-share the same bandwidth. The bandwidth utilization can be parititioned
+share the same bandwidth. The bandwidth utilization can be partitioned
 among channels based on the priority and weight assignments.
 
 There are only two priority levels and 15 weigh assignments possible.
 
 Other parameters here determine how much of the system bus this HIDMA
-instance can use like maximum read/write request and and number of bytes to
+instance can use like maximum read/write request and number of bytes to
 read/write in a single burst.
 
 Main node required properties:
-- 
1.9.1

[PATCH V5 03/10] of: irq: make of_msi_configure accessible from modules

[Sinan Kaya]

The of_msi_configure routine is only accessible by the built-in
kernel drivers. Export this function so that modules can use it
too.

This function is useful for configuring MSI on child device tree
nodes on hierarchical objects.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/of/irq.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index a2e68f7..20c09e0 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -767,3 +767,4 @@ void of_msi_configure(struct device *dev, struct device_node *np)
 	dev_set_msi_domain(dev,
 			   of_msi_get_domain(dev, np, DOMAIN_BUS_PLATFORM_MSI));
 }
+EXPORT_SYMBOL_GPL(of_msi_configure);
-- 
1.9.1

[PATCH V5 04/10] dmaengine: qcom_hidma: configure DMA and MSI for OF

[Sinan Kaya]

Configure the DMA bindings for the device tree based firmware.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/dma/qcom/hidma_mgmt.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/qcom/hidma_mgmt.c b/drivers/dma/qcom/hidma_mgmt.c
index 82f36e4..185d29c 100644
--- a/drivers/dma/qcom/hidma_mgmt.c
+++ b/drivers/dma/qcom/hidma_mgmt.c
@@ -375,8 +375,15 @@ static int __init hidma_mgmt_of_populate_channels(struct device_node *np)
 			ret = PTR_ERR(new_pdev);
 			goto out;
 		}
+		of_node_get(child);
+		new_pdev->dev.of_node = child;
 		of_dma_configure(&new_pdev->dev, child);
-
+		/*
+		 * It is assumed that calling of_msi_configure is safe on
+		 * platforms with or without MSI support.
+		 */
+		of_msi_configure(&new_pdev->dev, child);
+		of_node_put(child);
 		kfree(res);
 		res = NULL;
 	}
-- 
1.9.1

[PATCH V5 05/10] dmaengine: qcom_hidma: make pending_tre_count atomic

[Sinan Kaya]

Getting ready for the MSI interrupts. The pending_tre_count is used
in the interrupt handler to make sure all outstanding requests are
serviced.

The driver will allocate 11 MSI interrupts. Each MSI interrupt can be
assigned to a different CPU. Then, we have a race condition for common
variables as they share the same interrupt handler with a different
cause bit and they can potentially be executed in parallel. Making this
variable atomic so that it can be updated from multiple processor
contexts.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/dma/qcom/hidma.h     |  2 +-
 drivers/dma/qcom/hidma_dbg.c |  3 ++-
 drivers/dma/qcom/hidma_ll.c  | 13 ++++++-------
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/qcom/hidma.h b/drivers/dma/qcom/hidma.h
index b209942..afaeb9a 100644
--- a/drivers/dma/qcom/hidma.h
+++ b/drivers/dma/qcom/hidma.h
@@ -58,7 +58,7 @@ struct hidma_lldev {
 	void __iomem *evca;		/* Event Channel address          */
 	struct hidma_tre
 		**pending_tre_list;	/* Pointers to pending TREs	  */
-	s32 pending_tre_count;		/* Number of TREs pending	  */
+	atomic_t pending_tre_count;	/* Number of TREs pending	  */
 
 	void *tre_ring;			/* TRE ring			  */
 	dma_addr_t tre_dma;		/* TRE ring to be shared with HW  */
diff --git a/drivers/dma/qcom/hidma_dbg.c b/drivers/dma/qcom/hidma_dbg.c
index 3d83b99..3bdcb80 100644
--- a/drivers/dma/qcom/hidma_dbg.c
+++ b/drivers/dma/qcom/hidma_dbg.c
@@ -74,7 +74,8 @@ static void hidma_ll_devstats(struct seq_file *s, void *llhndl)
 	seq_printf(s, "tre_ring_handle=%pap\n", &lldev->tre_dma);
 	seq_printf(s, "tre_ring_size = 0x%x\n", lldev->tre_ring_size);
 	seq_printf(s, "tre_processed_off = 0x%x\n", lldev->tre_processed_off);
-	seq_printf(s, "pending_tre_count=%d\n", lldev->pending_tre_count);
+	seq_printf(s, "pending_tre_count=%d\n",
+			atomic_read(&lldev->pending_tre_count));
 	seq_printf(s, "evca=%p\n", lldev->evca);
 	seq_printf(s, "evre_ring=%p\n", lldev->evre_ring);
 	seq_printf(s, "evre_ring_handle=%pap\n", &lldev->evre_dma);
diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c
index ad20dfb..a4fc941 100644
--- a/drivers/dma/qcom/hidma_ll.c
+++ b/drivers/dma/qcom/hidma_ll.c
@@ -218,10 +218,9 @@ static int hidma_post_completed(struct hidma_lldev *lldev, int tre_iterator,
 	 * Keep track of pending TREs that SW is expecting to receive
 	 * from HW. We got one now. Decrement our counter.
 	 */
-	lldev->pending_tre_count--;
-	if (lldev->pending_tre_count < 0) {
+	if (atomic_dec_return(&lldev->pending_tre_count) < 0) {
 		dev_warn(lldev->dev, "tre count mismatch on completion");
-		lldev->pending_tre_count = 0;
+		atomic_set(&lldev->pending_tre_count, 0);
 	}
 
 	spin_unlock_irqrestore(&lldev->lock, flags);
@@ -321,7 +320,7 @@ void hidma_cleanup_pending_tre(struct hidma_lldev *lldev, u8 err_info,
 	u32 tre_read_off;
 
 	tre_iterator = lldev->tre_processed_off;
-	while (lldev->pending_tre_count) {
+	while (atomic_read(&lldev->pending_tre_count)) {
 		if (hidma_post_completed(lldev, tre_iterator, err_info,
 					 err_code))
 			break;
@@ -564,7 +563,7 @@ void hidma_ll_queue_request(struct hidma_lldev *lldev, u32 tre_ch)
 	tre->err_code = 0;
 	tre->err_info = 0;
 	tre->queued = 1;
-	lldev->pending_tre_count++;
+	atomic_inc(&lldev->pending_tre_count);
 	lldev->tre_write_offset = (lldev->tre_write_offset + HIDMA_TRE_SIZE)
 					% lldev->tre_ring_size;
 	spin_unlock_irqrestore(&lldev->lock, flags);
@@ -670,7 +669,7 @@ int hidma_ll_setup(struct hidma_lldev *lldev)
 	u32 val;
 	u32 nr_tres = lldev->nr_tres;
 
-	lldev->pending_tre_count = 0;
+	atomic_set(&lldev->pending_tre_count, 0);
 	lldev->tre_processed_off = 0;
 	lldev->evre_processed_off = 0;
 	lldev->tre_write_offset = 0;
@@ -834,7 +833,7 @@ int hidma_ll_uninit(struct hidma_lldev *lldev)
 	tasklet_kill(&lldev->rst_task);
 	memset(lldev->trepool, 0, required_bytes);
 	lldev->trepool = NULL;
-	lldev->pending_tre_count = 0;
+	atomic_set(&lldev->pending_tre_count, 0);
 	lldev->tre_write_offset = 0;
 
 	rc = hidma_ll_reset(lldev);
-- 
1.9.1

[PATCH V5 06/10] dmaengine: qcom_hidma: bring out interrupt cause

[Sinan Kaya]

Bring out the interrupt cause to the top level so that MSI interrupts
can be hooked at a later stage.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/dma/qcom/hidma_ll.c | 57 ++++++++++++++++++++++++++-------------------
 1 file changed, 33 insertions(+), 24 deletions(-)

diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c
index a4fc941..015df4b 100644
--- a/drivers/dma/qcom/hidma_ll.c
+++ b/drivers/dma/qcom/hidma_ll.c
@@ -432,12 +432,24 @@ static void hidma_ll_abort(unsigned long arg)
  * requests traditionally to the destination, this concept does not apply
  * here for this HW.
  */
-irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
+static void hidma_ll_int_handler_internal(struct hidma_lldev *lldev, int cause)
 {
-	struct hidma_lldev *lldev = arg;
-	u32 status;
-	u32 enable;
-	u32 cause;
+	if (cause & HIDMA_ERR_INT_MASK) {
+		dev_err(lldev->dev, "error 0x%x, disabling...\n",
+				cause);
+
+		/* Clear out pending interrupts */
+		writel(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+
+		/* No further submissions. */
+		hidma_ll_disable(lldev);
+
+		/* Driver completes the txn and intimates the client.*/
+		hidma_cleanup_pending_tre(lldev, 0xFF,
+					  HIDMA_EVRE_STATUS_ERROR);
+
+		return;
+	}
 
 	/*
 	 * Fine tuned for this HW...
@@ -446,30 +458,28 @@ irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
 	 * read and write accessors are used for performance reasons due to
 	 * interrupt delivery guarantees. Do not copy this code blindly and
 	 * expect that to work.
+	 *
+	 * Try to consume as many EVREs as possible.
 	 */
+	hidma_handle_tre_completion(lldev);
+
+	/* We consumed TREs or there are pending TREs or EVREs. */
+	writel_relaxed(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+}
+
+irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
+{
+	struct hidma_lldev *lldev = arg;
+	u32 status;
+	u32 enable;
+	u32 cause;
+
 	status = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
 	enable = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
 	cause = status & enable;
 
 	while (cause) {
-		if (cause & HIDMA_ERR_INT_MASK) {
-			dev_err(lldev->dev, "error 0x%x, resetting...\n",
-					cause);
-
-			/* Clear out pending interrupts */
-			writel(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
-
-			tasklet_schedule(&lldev->rst_task);
-			goto out;
-		}
-
-		/*
-		 * Try to consume as many EVREs as possible.
-		 */
-		hidma_handle_tre_completion(lldev);
-
-		/* We consumed TREs or there are pending TREs or EVREs. */
-		writel_relaxed(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+		hidma_ll_int_handler_internal(lldev, cause);
 
 		/*
 		 * Another interrupt might have arrived while we are
@@ -480,7 +490,6 @@ irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
 		cause = status & enable;
 	}
 
-out:
 	return IRQ_HANDLED;
 }
 
-- 
1.9.1

[PATCH V5 07/10] dmaengine: qcom_hidma: add a common API to setup the interrupt

[Sinan Kaya]

Introducing the hidma_ll_setup_irq function to set up the interrupt
type externally from the OS interface.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/dma/qcom/hidma.h    |  2 ++
 drivers/dma/qcom/hidma_ll.c | 27 +++++++++++++++++++++++----
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/qcom/hidma.h b/drivers/dma/qcom/hidma.h
index afaeb9a..b74a56e 100644
--- a/drivers/dma/qcom/hidma.h
+++ b/drivers/dma/qcom/hidma.h
@@ -46,6 +46,7 @@ struct hidma_tre {
 };
 
 struct hidma_lldev {
+	bool msi_support;		/* flag indicating MSI support    */
 	bool initialized;		/* initialized flag               */
 	u8 trch_state;			/* trch_state of the device	  */
 	u8 evch_state;			/* evch_state of the device	  */
@@ -148,6 +149,7 @@ int hidma_ll_disable(struct hidma_lldev *lldev);
 int hidma_ll_enable(struct hidma_lldev *llhndl);
 void hidma_ll_set_transfer_params(struct hidma_lldev *llhndl, u32 tre_ch,
 	dma_addr_t src, dma_addr_t dest, u32 len, u32 flags);
+void hidma_ll_setup_irq(struct hidma_lldev *lldev, bool msi);
 int hidma_ll_setup(struct hidma_lldev *lldev);
 struct hidma_lldev *hidma_ll_init(struct device *dev, u32 max_channels,
 			void __iomem *trca, void __iomem *evca,
diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c
index 015df4b..9d78c86 100644
--- a/drivers/dma/qcom/hidma_ll.c
+++ b/drivers/dma/qcom/hidma_ll.c
@@ -715,17 +715,36 @@ int hidma_ll_setup(struct hidma_lldev *lldev)
 	writel(HIDMA_EVRE_SIZE * nr_tres,
 			lldev->evca + HIDMA_EVCA_RING_LEN_REG);
 
-	/* support IRQ only for now */
+	/* configure interrupts */
+	hidma_ll_setup_irq(lldev, lldev->msi_support);
+
+	rc = hidma_ll_enable(lldev);
+	if (rc)
+		return rc;
+
+	return rc;
+}
+
+void hidma_ll_setup_irq(struct hidma_lldev *lldev, bool msi)
+{
+	u32 val;
+
+	lldev->msi_support = msi;
+
+	/* disable interrupts again after reset */
+	writel(0, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+	writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
+
+	/* support IRQ by default */
 	val = readl(lldev->evca + HIDMA_EVCA_INTCTRL_REG);
 	val &= ~0xF;
-	val |= 0x1;
+	if (!lldev->msi_support)
+		val = val | 0x1;
 	writel(val, lldev->evca + HIDMA_EVCA_INTCTRL_REG);
 
 	/* clear all pending interrupts and enable them */
 	writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
 	writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
-
-	return hidma_ll_enable(lldev);
 }
 
 struct hidma_lldev *hidma_ll_init(struct device *dev, u32 nr_tres,
-- 
1.9.1

[PATCH V5 08/10] dmaengine: qcom_hidma: protect common data structures

[Sinan Kaya]

When MSI interrupts are supported, error and the transfer interrupt can
come from multiple processor contexts.

Each error interrupt is an MSI interrupt. If the channel is disabled by
the first error interrupt, the remaining error interrupts will gracefully
return in the interrupt handler.

If an error is observed while servicing the completions in success case,
the posting of the completions will be aborted as soon as channel disabled
state is observed. The error interrupt handler will take it from there and
finish the remaining completions. We don't want to create multiple success
and error messages to be delivered to the client in mixed order.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/dma/qcom/hidma_ll.c | 44 +++++++++++---------------------------------
 1 file changed, 11 insertions(+), 33 deletions(-)

diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c
index 9d78c86..c4e8b64 100644
--- a/drivers/dma/qcom/hidma_ll.c
+++ b/drivers/dma/qcom/hidma_ll.c
@@ -198,13 +198,16 @@ static void hidma_ll_tre_complete(unsigned long arg)
 	}
 }
 
-static int hidma_post_completed(struct hidma_lldev *lldev, int tre_iterator,
-				u8 err_info, u8 err_code)
+static int hidma_post_completed(struct hidma_lldev *lldev, u8 err_info,
+				u8 err_code)
 {
 	struct hidma_tre *tre;
 	unsigned long flags;
+	u32 tre_iterator;
 
 	spin_lock_irqsave(&lldev->lock, flags);
+
+	tre_iterator = lldev->tre_processed_off;
 	tre = lldev->pending_tre_list[tre_iterator / HIDMA_TRE_SIZE];
 	if (!tre) {
 		spin_unlock_irqrestore(&lldev->lock, flags);
@@ -223,6 +226,9 @@ static int hidma_post_completed(struct hidma_lldev *lldev, int tre_iterator,
 		atomic_set(&lldev->pending_tre_count, 0);
 	}
 
+	HIDMA_INCREMENT_ITERATOR(tre_iterator, HIDMA_TRE_SIZE,
+				 lldev->tre_ring_size);
+	lldev->tre_processed_off = tre_iterator;
 	spin_unlock_irqrestore(&lldev->lock, flags);
 
 	tre->err_info = err_info;
@@ -244,13 +250,11 @@ static int hidma_post_completed(struct hidma_lldev *lldev, int tre_iterator,
 static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
 {
 	u32 evre_ring_size = lldev->evre_ring_size;
-	u32 tre_ring_size = lldev->tre_ring_size;
 	u32 err_info, err_code, evre_write_off;
-	u32 tre_iterator, evre_iterator;
+	u32 evre_iterator;
 	u32 num_completed = 0;
 
 	evre_write_off = readl_relaxed(lldev->evca + HIDMA_EVCA_WRITE_PTR_REG);
-	tre_iterator = lldev->tre_processed_off;
 	evre_iterator = lldev->evre_processed_off;
 
 	if ((evre_write_off > evre_ring_size) ||
@@ -273,12 +277,9 @@ static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
 		err_code =
 		    (cfg >> HIDMA_EVRE_CODE_BIT_POS) & HIDMA_EVRE_CODE_MASK;
 
-		if (hidma_post_completed(lldev, tre_iterator, err_info,
-					 err_code))
+		if (hidma_post_completed(lldev, err_info, err_code))
 			break;
 
-		HIDMA_INCREMENT_ITERATOR(tre_iterator, HIDMA_TRE_SIZE,
-					 tre_ring_size);
 		HIDMA_INCREMENT_ITERATOR(evre_iterator, HIDMA_EVRE_SIZE,
 					 evre_ring_size);
 
@@ -295,16 +296,10 @@ static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
 	if (num_completed) {
 		u32 evre_read_off = (lldev->evre_processed_off +
 				     HIDMA_EVRE_SIZE * num_completed);
-		u32 tre_read_off = (lldev->tre_processed_off +
-				    HIDMA_TRE_SIZE * num_completed);
-
 		evre_read_off = evre_read_off % evre_ring_size;
-		tre_read_off = tre_read_off % tre_ring_size;
-
 		writel(evre_read_off, lldev->evca + HIDMA_EVCA_DOORBELL_REG);
 
 		/* record the last processed tre offset */
-		lldev->tre_processed_off = tre_read_off;
 		lldev->evre_processed_off = evre_read_off;
 	}
 
@@ -314,27 +309,10 @@ static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
 void hidma_cleanup_pending_tre(struct hidma_lldev *lldev, u8 err_info,
 			       u8 err_code)
 {
-	u32 tre_iterator;
-	u32 tre_ring_size = lldev->tre_ring_size;
-	int num_completed = 0;
-	u32 tre_read_off;
-
-	tre_iterator = lldev->tre_processed_off;
 	while (atomic_read(&lldev->pending_tre_count)) {
-		if (hidma_post_completed(lldev, tre_iterator, err_info,
-					 err_code))
+		if (hidma_post_completed(lldev, err_info, err_code))
 			break;
-		HIDMA_INCREMENT_ITERATOR(tre_iterator, HIDMA_TRE_SIZE,
-					 tre_ring_size);
-		num_completed++;
 	}
-	tre_read_off = (lldev->tre_processed_off +
-			HIDMA_TRE_SIZE * num_completed);
-
-	tre_read_off = tre_read_off % tre_ring_size;
-
-	/* record the last processed tre offset */
-	lldev->tre_processed_off = tre_read_off;
 }
 
 static int hidma_ll_reset(struct hidma_lldev *lldev)
-- 
1.9.1

[PATCH V5 09/10] dmaengine: qcom_hidma: break completion processing on error

[Sinan Kaya]

We try to consume as much successful transfers as possible. Now that we
support MSI interrupts, an error interrupt might be observed by another
processor while we are finishing the successful ones.

Try to abort successful processing if this is the case.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/dma/qcom/hidma_ll.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c
index c4e8b64..aa76ec1 100644
--- a/drivers/dma/qcom/hidma_ll.c
+++ b/drivers/dma/qcom/hidma_ll.c
@@ -291,6 +291,13 @@ static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
 		evre_write_off =
 		    readl_relaxed(lldev->evca + HIDMA_EVCA_WRITE_PTR_REG);
 		num_completed++;
+
+		/*
+		 * An error interrupt might have arrived while we are processing
+		 * the completed interrupt.
+		 */
+		if (!hidma_ll_isenabled(lldev))
+			break;
 	}
 
 	if (num_completed) {
-- 
1.9.1

[PATCH V5 10/10] dmaengine: qcom_hidma: add MSI support for interrupts

[Sinan Kaya]

The interrupts can now be delivered as platform MSI interrupts on newer
platforms. The code looks for a new OF and ACPI strings in order to enable
the functionality.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/dma/qcom/hidma.c    | 143 ++++++++++++++++++++++++++++++++++++++++++--
 drivers/dma/qcom/hidma.h    |   2 +
 drivers/dma/qcom/hidma_ll.c |   8 +++
 3 files changed, 147 insertions(+), 6 deletions(-)

diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c
index 10a9e3a..7b13213 100644
--- a/drivers/dma/qcom/hidma.c
+++ b/drivers/dma/qcom/hidma.c
@@ -56,6 +56,7 @@
 #include <linux/irq.h>
 #include <linux/atomic.h>
 #include <linux/pm_runtime.h>
+#include <linux/msi.h>
 
 #include "../dmaengine.h"
 #include "hidma.h"
@@ -70,6 +71,7 @@
 #define HIDMA_ERR_INFO_SW			0xFF
 #define HIDMA_ERR_CODE_UNEXPECTED_TERMINATE	0x0
 #define HIDMA_NR_DEFAULT_DESC			10
+#define HIDMA_MSI_INTS				11
 
 static inline struct hidma_dev *to_hidma_dev(struct dma_device *dmadev)
 {
@@ -530,6 +532,15 @@ static irqreturn_t hidma_chirq_handler(int chirq, void *arg)
 	return hidma_ll_inthandler(chirq, lldev);
 }
 
+static irqreturn_t hidma_chirq_handler_msi(int chirq, void *arg)
+{
+	struct hidma_lldev **lldevp = arg;
+	struct hidma_dev *dmadev = to_hidma_dev_from_lldev(lldevp);
+
+	return hidma_ll_inthandler_msi(chirq, *lldevp,
+				       1 << (chirq - dmadev->msi_virqbase));
+}
+
 static ssize_t hidma_show_values(struct device *dev,
 				 struct device_attribute *attr, char *buf)
 {
@@ -584,6 +595,104 @@ static int hidma_sysfs_init(struct hidma_dev *dev)
 	return device_create_file(dev->ddev.dev, dev->chid_attrs);
 }
 
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+static void hidma_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
+{
+	struct device *dev = msi_desc_to_dev(desc);
+	struct hidma_dev *dmadev = dev_get_drvdata(dev);
+
+	if (!desc->platform.msi_index) {
+		writel(msg->address_lo, dmadev->dev_evca + 0x118);
+		writel(msg->address_hi, dmadev->dev_evca + 0x11C);
+		writel(msg->data, dmadev->dev_evca + 0x120);
+	}
+}
+#endif
+
+static void hidma_free_msis(struct hidma_dev *dmadev)
+{
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+	struct device *dev = dmadev->ddev.dev;
+	struct msi_desc *desc;
+
+	/* free allocated MSI interrupts above */
+	for_each_msi_entry(desc, dev)
+		devm_free_irq(dev, desc->irq, &dmadev->lldev);
+
+	platform_msi_domain_free_irqs(dev);
+#endif
+}
+
+static int hidma_request_msi(struct hidma_dev *dmadev,
+			     struct platform_device *pdev)
+{
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+	int rc;
+	struct msi_desc *desc;
+	struct msi_desc *failed_desc = NULL;
+
+	rc = platform_msi_domain_alloc_irqs(&pdev->dev, HIDMA_MSI_INTS,
+					    hidma_write_msi_msg);
+	if (rc)
+		return rc;
+
+	for_each_msi_entry(desc, &pdev->dev) {
+		if (!desc->platform.msi_index)
+			dmadev->msi_virqbase = desc->irq;
+
+		rc = devm_request_irq(&pdev->dev, desc->irq,
+				       hidma_chirq_handler_msi,
+				       0, "qcom-hidma-msi",
+				       &dmadev->lldev);
+		if (rc) {
+			failed_desc = desc;
+			break;
+		}
+	}
+
+	if (rc) {
+		/* free allocated MSI interrupts above */
+		for_each_msi_entry(desc, &pdev->dev) {
+			if (desc == failed_desc)
+				break;
+			devm_free_irq(&pdev->dev, desc->irq,
+				      &dmadev->lldev);
+		}
+	} else {
+		/* Add callback to free MSIs on teardown */
+		hidma_ll_setup_irq(dmadev->lldev, true);
+
+	}
+	if (rc)
+		dev_warn(&pdev->dev,
+			 "failed to request MSI irq, falling back to wired IRQ\n");
+	return rc;
+#else
+	return -EINVAL;
+#endif
+}
+
+static bool hidma_msi_capable(struct device *dev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	const char *of_compat;
+	int ret = -EINVAL;
+
+	if (!adev || acpi_disabled) {
+		ret = device_property_read_string(dev, "compatible",
+						  &of_compat);
+		if (ret)
+			return false;
+
+		ret = strcmp(of_compat, "qcom,hidma-1.1");
+	} else {
+#ifdef CONFIG_ACPI
+		ret = strcmp(acpi_device_hid(adev), "QCOM8062");
+#endif
+	}
+	return ret == 0;
+}
+
 static int hidma_probe(struct platform_device *pdev)
 {
 	struct hidma_dev *dmadev;
@@ -593,6 +702,7 @@ static int hidma_probe(struct platform_device *pdev)
 	void __iomem *evca;
 	void __iomem *trca;
 	int rc;
+	bool msi;
 
 	pm_runtime_set_autosuspend_delay(&pdev->dev, HIDMA_AUTOSUSPEND_TIMEOUT);
 	pm_runtime_use_autosuspend(&pdev->dev);
@@ -654,6 +764,12 @@ static int hidma_probe(struct platform_device *pdev)
 	dmadev->ddev.device_terminate_all = hidma_terminate_all;
 	dmadev->ddev.copy_align = 8;
 
+	/*
+	 * Determine the MSI capability of the platform. Old HW doesn't
+	 * support MSI.
+	 */
+	msi = hidma_msi_capable(&pdev->dev);
+
 	device_property_read_u32(&pdev->dev, "desc-count",
 				 &dmadev->nr_descriptors);
 
@@ -682,10 +798,17 @@ static int hidma_probe(struct platform_device *pdev)
 		goto dmafree;
 	}
 
-	rc = devm_request_irq(&pdev->dev, chirq, hidma_chirq_handler, 0,
-			      "qcom-hidma", dmadev->lldev);
-	if (rc)
-		goto uninit;
+	platform_set_drvdata(pdev, dmadev);
+	if (msi)
+		rc = hidma_request_msi(dmadev, pdev);
+
+	if (!msi || rc) {
+		hidma_ll_setup_irq(dmadev->lldev, false);
+		rc = devm_request_irq(&pdev->dev, chirq, hidma_chirq_handler,
+				      0, "qcom-hidma", dmadev->lldev);
+		if (rc)
+			goto uninit;
+	}
 
 	INIT_LIST_HEAD(&dmadev->ddev.channels);
 	rc = hidma_chan_init(dmadev, 0);
@@ -701,12 +824,14 @@ static int hidma_probe(struct platform_device *pdev)
 	hidma_debug_init(dmadev);
 	hidma_sysfs_init(dmadev);
 	dev_info(&pdev->dev, "HI-DMA engine driver registration complete\n");
-	platform_set_drvdata(pdev, dmadev);
 	pm_runtime_mark_last_busy(dmadev->ddev.dev);
 	pm_runtime_put_autosuspend(dmadev->ddev.dev);
 	return 0;
 
 uninit:
+	if (msi)
+		hidma_free_msis(dmadev);
+
 	hidma_debug_uninit(dmadev);
 	hidma_ll_uninit(dmadev->lldev);
 dmafree:
@@ -724,7 +849,11 @@ static int hidma_remove(struct platform_device *pdev)
 
 	pm_runtime_get_sync(dmadev->ddev.dev);
 	dma_async_device_unregister(&dmadev->ddev);
-	devm_free_irq(dmadev->ddev.dev, dmadev->irq, dmadev->lldev);
+	if (!dmadev->lldev->msi_support)
+		devm_free_irq(dmadev->ddev.dev, dmadev->irq, dmadev->lldev);
+	else
+		hidma_free_msis(dmadev);
+
 	tasklet_kill(&dmadev->task);
 	hidma_sysfs_uninit(dmadev);
 	hidma_debug_uninit(dmadev);
@@ -741,12 +870,14 @@ static int hidma_remove(struct platform_device *pdev)
 #if IS_ENABLED(CONFIG_ACPI)
 static const struct acpi_device_id hidma_acpi_ids[] = {
 	{"QCOM8061"},
+	{"QCOM8062"},
 	{},
 };
 #endif
 
 static const struct of_device_id hidma_match[] = {
 	{.compatible = "qcom,hidma-1.0",},
+	{.compatible = "qcom,hidma-1.1",},
 	{},
 };
 MODULE_DEVICE_TABLE(of, hidma_match);
diff --git a/drivers/dma/qcom/hidma.h b/drivers/dma/qcom/hidma.h
index b74a56e..b6a9028 100644
--- a/drivers/dma/qcom/hidma.h
+++ b/drivers/dma/qcom/hidma.h
@@ -115,6 +115,7 @@ struct hidma_dev {
 	int				irq;
 	int				chidx;
 	u32				nr_descriptors;
+	int				msi_virqbase;
 
 	struct hidma_lldev		*lldev;
 	void				__iomem *dev_trca;
@@ -156,6 +157,7 @@ struct hidma_lldev *hidma_ll_init(struct device *dev, u32 max_channels,
 			u8 chidx);
 int hidma_ll_uninit(struct hidma_lldev *llhndl);
 irqreturn_t hidma_ll_inthandler(int irq, void *arg);
+irqreturn_t hidma_ll_inthandler_msi(int irq, void *arg, int cause);
 void hidma_cleanup_pending_tre(struct hidma_lldev *llhndl, u8 err_info,
 				u8 err_code);
 int hidma_debug_init(struct hidma_dev *dmadev);
diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c
index aa76ec1..40bcf31 100644
--- a/drivers/dma/qcom/hidma_ll.c
+++ b/drivers/dma/qcom/hidma_ll.c
@@ -478,6 +478,14 @@ irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
 	return IRQ_HANDLED;
 }
 
+irqreturn_t hidma_ll_inthandler_msi(int chirq, void *arg, int cause)
+{
+	struct hidma_lldev *lldev = arg;
+
+	hidma_ll_int_handler_internal(lldev, cause);
+	return IRQ_HANDLED;
+}
+
 int hidma_ll_enable(struct hidma_lldev *lldev)
 {
 	u32 val;
-- 
1.9.1