[PATCH V2 0/4] PCI: ACPI: Setting up DMA coherency for PCI device from _CCA attribute

[PATCH V2 0/4] PCI: ACPI: Setting up DMA coherency for PCI device from _CCA attribute

[Suravee Suthikulpanit]

This patch adds support to setup DMA coherency for PCI device using
the ACPI _CCA attribute. According to the ACPI spec, the _CCA attribute
is required for ARM64. Therefore, this patch is a pre-req for ACPI PCI
support for ARM64 which is currently in development.

Also, this should not affect other architectures that does not define 
CONFIG_ACPI_CCA_REQUIRED, since the default value is coherent.

In the V2 of this patch series, I have pulled in the following patch from Jeremy
before cleaning up the acpi_check_dma() function (in patch 2).

    http://www.spinics.net/lists/linux-usb/msg128582.html)

Changes from V1: (https://lkml.org/lkml/2015/8/13/182)
    * Include patch 1 from Jeremy to enable support for _CCA=0
    * Clean up acpi_check_dma() per Bjorn suggestions
    * Split the original V1 patch into two patches (patch 3 and 4)

Jeremy Linton (1):
  Honor ACPI _CCA attribute setting

Suravee Suthikulpanit (3):
  ACPI/scan: Clean up acpi_check_dma
  PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()
  PCI: ACPI: Add support for PCI device DMA coherency

 drivers/acpi/acpi_platform.c |  7 ++++++-
 drivers/acpi/glue.c          |  5 +++--
 drivers/acpi/scan.c          | 39 +++++++++++++++++++++++++++++++++++++++
 drivers/base/property.c      |  8 ++++++--
 drivers/of/of_pci.c          | 20 --------------------
 drivers/pci/probe.c          | 32 ++++++++++++++++++++++++++++++--
 include/acpi/acpi_bus.h      | 35 ++---------------------------------
 include/linux/acpi.h         |  4 ++--
 include/linux/of_pci.h       |  3 ---
 9 files changed, 88 insertions(+), 65 deletions(-)

-- 
2.1.0

[PATCH V2 1/4] Honor ACPI _CCA attribute setting

[Suravee Suthikulpanit]

From: Jeremy Linton <jeremy.linton@arm.com>

ACPI configurations can now mark devices as noncoherent,
support that choice.

NOTE: This is required to support USB on ARM Juno Development Board.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Rob Herring <robh+dt@kernel.org>
CC: Will Deacon <will.deacon@arm.com>
CC: Rafael J. Wysocki <rjw@rjwysocki.net>
---
 include/acpi/acpi_bus.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 83061ca..7ecb8e4 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -399,7 +399,7 @@ static inline bool acpi_check_dma(struct acpi_device *adev, bool *coherent)
 	 * case 1. Do not support and disable DMA.
 	 * case 2. Support but rely on arch-specific cache maintenance for
 	 *         non-coherence DMA operations.
-	 * Currently, we implement case 1 above.
+	 * Currently, we implement case 2 above.
 	 *
 	 * For the case when _CCA is missing (i.e. cca_seen=0) and
 	 * platform specifies ACPI_CCA_REQUIRED, we do not support DMA,
@@ -407,7 +407,8 @@ static inline bool acpi_check_dma(struct acpi_device *adev, bool *coherent)
 	 *
 	 * See acpi_init_coherency() for more info.
 	 */
-	if (adev->flags.coherent_dma) {
+	if (adev->flags.coherent_dma ||
+	    (adev->flags.cca_seen && IS_ENABLED(CONFIG_ARM64))) {
 		ret = true;
 		if (coherent)
 			*coherent = adev->flags.coherent_dma;
-- 
2.1.0

[PATCH V2 2/4] ACPI/scan: Clean up acpi_check_dma

[Suravee Suthikulpanit]

The original name of acpi_check_dma() function does not clearly tell what
exactly it is checking. Also, returning two boolean values (one to indicate
device is DMA capability, and the other to inidicate device coherency
attribute) can be confusing.

So, in order to simplify the function, this patch renames acpi_check_dma()
to acpi_check_dma_coherency() to clearly indicate the purpose of this
function, and only returns an integer where -1 means DMA not supported,
1 means coherent DMA, and 0 means non-coherent DMA.

Also, this patch moves the function into drivers/acpi/scan.c since
it is easier to follow the logic in the acpi_init_coherency() in the
same file here.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Rob Herring <robh+dt@kernel.org>
CC: Will Deacon <will.deacon@arm.com>
CC: Rafael J. Wysocki <rjw@rjwysocki.net>
---
 drivers/acpi/acpi_platform.c |  7 ++++++-
 drivers/acpi/glue.c          |  5 +++--
 drivers/acpi/scan.c          | 39 +++++++++++++++++++++++++++++++++++++++
 drivers/base/property.c      |  8 ++++++--
 include/acpi/acpi_bus.h      | 36 ++----------------------------------
 include/linux/acpi.h         |  4 ++--
 6 files changed, 58 insertions(+), 41 deletions(-)

diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
index 06a67d5..2261e85 100644
--- a/drivers/acpi/acpi_platform.c
+++ b/drivers/acpi/acpi_platform.c
@@ -103,7 +103,12 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
 	pdevinfo.res = resources;
 	pdevinfo.num_res = count;
 	pdevinfo.fwnode = acpi_fwnode_handle(adev);
-	pdevinfo.dma_mask = acpi_check_dma(adev, NULL) ? DMA_BIT_MASK(32) : 0;
+
+	if (-1 != acpi_check_dma_coherency(adev))
+		pdevinfo.dma_mask = DMA_BIT_MASK(32);
+	else
+		pdevinfo.dma_mask = 0;
+
 	pdev = platform_device_register_full(&pdevinfo);
 	if (IS_ERR(pdev))
 		dev_err(&adev->dev, "platform device creation failed: %ld\n",
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index b9657af..55cf916 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -168,7 +168,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 	struct list_head *physnode_list;
 	unsigned int node_id;
 	int retval = -EINVAL;
-	bool coherent;
+	int coherent;
 
 	if (has_acpi_companion(dev)) {
 		if (acpi_dev) {
@@ -225,7 +225,8 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 	if (!has_acpi_companion(dev))
 		ACPI_COMPANION_SET(dev, acpi_dev);
 
-	if (acpi_check_dma(acpi_dev, &coherent))
+	coherent = acpi_check_dma_coherency(acpi_dev);
+	if (coherent != -1)
 		arch_setup_dma_ops(dev, 0, 0, NULL, coherent);
 
 	acpi_physnode_link_name(physical_node_name, node_id);
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index ec25635..299a825 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2182,6 +2182,45 @@ void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
 	kfree(pnp->unique_id);
 }
 
+/**
+ * acpi_check_dma_coherency - Check DMA coherency for the specified device.
+ * @adev: The pointer to acpi device to check coherency attribute
+ *
+ * Return -1 if DMA is not supported. Otherwise, return 1 if the
+ * device support coherent DMA, or 0 for non-coherent DMA.
+ */
+int acpi_check_dma_coherency(struct acpi_device *adev)
+{
+	int ret = -1;
+
+	if (!adev)
+		return ret;
+
+	/**
+	 * Currently, we only support _CCA=1 (i.e. coherent_dma=1)
+	 * This should be equivalent to specifying dma-coherent for
+	 * a device in OF.
+	 *
+	 * For the case when _CCA=0 (i.e. coherent_dma=0 && cca_seen=1),
+	 * we have two choices:
+	 *   1. Do not support and disable DMA.
+	 *   2. Support but rely on arch-specific cache maintenance for
+	 *      non-coherenje DMA operations.
+	 * Currently, we implement case 2 above.
+	 *
+	 * For the case when _CCA is missing (i.e. cca_seen=0) and
+	 * platform specifies ACPI_CCA_REQUIRED, we do not support DMA,
+	 * and fallback to arch-specific default handling.
+	 *
+	 * See acpi_init_coherency() for more info.
+	 */
+	if (!adev->flags.cca_seen && IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
+		return ret;
+
+	return adev->flags.coherent_dma;
+}
+EXPORT_SYMBOL_GPL(acpi_check_dma_coherency);
+
 static void acpi_init_coherency(struct acpi_device *adev)
 {
 	unsigned long long cca = 0;
diff --git a/drivers/base/property.c b/drivers/base/property.c
index f3f6d16..643b0fb 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -527,8 +527,12 @@ bool device_dma_is_coherent(struct device *dev)
 
 	if (IS_ENABLED(CONFIG_OF) && dev->of_node)
 		coherent = of_dma_is_coherent(dev->of_node);
-	else
-		acpi_check_dma(ACPI_COMPANION(dev), &coherent);
+	else {
+		int ac = acpi_check_dma_coherency(ACPI_COMPANION(dev));
+
+		if (ac != -1)
+			coherent = ac;
+	}
 
 	return coherent;
 }
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 7ecb8e4..baf43ea 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -382,40 +382,6 @@ struct acpi_device {
 	void (*remove)(struct acpi_device *);
 };
 
-static inline bool acpi_check_dma(struct acpi_device *adev, bool *coherent)
-{
-	bool ret = false;
-
-	if (!adev)
-		return ret;
-
-	/**
-	 * Currently, we only support _CCA=1 (i.e. coherent_dma=1)
-	 * This should be equivalent to specifyig dma-coherent for
-	 * a device in OF.
-	 *
-	 * For the case when _CCA=0 (i.e. coherent_dma=0 && cca_seen=1),
-	 * There are two cases:
-	 * case 1. Do not support and disable DMA.
-	 * case 2. Support but rely on arch-specific cache maintenance for
-	 *         non-coherence DMA operations.
-	 * Currently, we implement case 2 above.
-	 *
-	 * For the case when _CCA is missing (i.e. cca_seen=0) and
-	 * platform specifies ACPI_CCA_REQUIRED, we do not support DMA,
-	 * and fallback to arch-specific default handling.
-	 *
-	 * See acpi_init_coherency() for more info.
-	 */
-	if (adev->flags.coherent_dma ||
-	    (adev->flags.cca_seen && IS_ENABLED(CONFIG_ARM64))) {
-		ret = true;
-		if (coherent)
-			*coherent = adev->flags.coherent_dma;
-	}
-	return ret;
-}
-
 static inline bool is_acpi_node(struct fwnode_handle *fwnode)
 {
 	return fwnode && fwnode->type == FWNODE_ACPI;
@@ -640,6 +606,8 @@ static inline bool acpi_device_can_poweroff(struct acpi_device *adev)
 	return adev->power.states[ACPI_STATE_D3_COLD].flags.valid;
 }
 
+int acpi_check_dma_coherency(struct acpi_device *adev);
+
 #else	/* CONFIG_ACPI */
 
 static inline int register_acpi_bus_type(void *bus) { return 0; }
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index d2445fa..530d2fa 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -562,9 +562,9 @@ static inline int acpi_device_modalias(struct device *dev,
 	return -ENODEV;
 }
 
-static inline bool acpi_check_dma(struct acpi_device *adev, bool *coherent)
+static inline int acpi_check_dma_coherency(struct acpi_device *adev)
 {
-	return false;
+	return -1;
 }
 
 #define ACPI_PTR(_ptr)	(NULL)
-- 
2.1.0

Re: [PATCH V2 2/4] ACPI/scan: Clean up acpi_check_dma

[Rafael J. Wysocki]

On Wednesday, August 26, 2015 12:33:27 AM Suravee Suthikulpanit wrote:
> The original name of acpi_check_dma() function does not clearly tell what
> exactly it is checking. Also, returning two boolean values (one to indicate
> device is DMA capability, and the other to inidicate device coherency
> attribute) can be confusing.
> 
> So, in order to simplify the function, this patch renames acpi_check_dma()
> to acpi_check_dma_coherency() to clearly indicate the purpose of this
> function, and only returns an integer where -1 means DMA not supported,
> 1 means coherent DMA, and 0 means non-coherent DMA.
> 
> Also, this patch moves the function into drivers/acpi/scan.c since
> it is easier to follow the logic in the acpi_init_coherency() in the
> same file here.
> 
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> CC: Bjorn Helgaas <bhelgaas@google.com>
> CC: Catalin Marinas <catalin.marinas@arm.com>
> CC: Rob Herring <robh+dt@kernel.org>
> CC: Will Deacon <will.deacon@arm.com>
> CC: Rafael J. Wysocki <rjw@rjwysocki.net>
> ---
>  drivers/acpi/acpi_platform.c |  7 ++++++-
>  drivers/acpi/glue.c          |  5 +++--
>  drivers/acpi/scan.c          | 39 +++++++++++++++++++++++++++++++++++++++
>  drivers/base/property.c      |  8 ++++++--
>  include/acpi/acpi_bus.h      | 36 ++----------------------------------
>  include/linux/acpi.h         |  4 ++--
>  6 files changed, 58 insertions(+), 41 deletions(-)
> 
> diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
> index 06a67d5..2261e85 100644
> --- a/drivers/acpi/acpi_platform.c
> +++ b/drivers/acpi/acpi_platform.c
> @@ -103,7 +103,12 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
>  	pdevinfo.res = resources;
>  	pdevinfo.num_res = count;
>  	pdevinfo.fwnode = acpi_fwnode_handle(adev);
> -	pdevinfo.dma_mask = acpi_check_dma(adev, NULL) ? DMA_BIT_MASK(32) : 0;
> +
> +	if (-1 != acpi_check_dma_coherency(adev))
> +		pdevinfo.dma_mask = DMA_BIT_MASK(32);
> +	else
> +		pdevinfo.dma_mask = 0;
> +
>  	pdev = platform_device_register_full(&pdevinfo);
>  	if (IS_ERR(pdev))
>  		dev_err(&adev->dev, "platform device creation failed: %ld\n",
> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
> index b9657af..55cf916 100644
> --- a/drivers/acpi/glue.c
> +++ b/drivers/acpi/glue.c
> @@ -168,7 +168,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>  	struct list_head *physnode_list;
>  	unsigned int node_id;
>  	int retval = -EINVAL;
> -	bool coherent;
> +	int coherent;

enum, anyone?  With clearly defined values?


>  
>  	if (has_acpi_companion(dev)) {
>  		if (acpi_dev) {
> @@ -225,7 +225,8 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>  	if (!has_acpi_companion(dev))
>  		ACPI_COMPANION_SET(dev, acpi_dev);
>  
> -	if (acpi_check_dma(acpi_dev, &coherent))
> +	coherent = acpi_check_dma_coherency(acpi_dev);
> +	if (coherent != -1)

Like here I'm not sure why -1 is special?


>  		arch_setup_dma_ops(dev, 0, 0, NULL, coherent);
>  
>  	acpi_physnode_link_name(physical_node_name, node_id);

Thanks,
Rafael

Re: [PATCH V2 2/4] ACPI/scan: Clean up acpi_check_dma

[Suravee Suthikulpanit]

Hi Rafael,

On 8/26/15 06:48, Rafael J. Wysocki wrote:

>[...]
> On Wednesday, August 26, 2015 12:33:27 AM Suravee Suthikulpanit wrote:
>> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
>> index b9657af..55cf916 100644
>> --- a/drivers/acpi/glue.c
>> +++ b/drivers/acpi/glue.c
>> @@ -168,7 +168,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>>   	struct list_head *physnode_list;
>>   	unsigned int node_id;
>>   	int retval = -EINVAL;
>> -	bool coherent;
>> +	int coherent;
>
> enum, anyone?  With clearly defined values?

Originally I had defined

enum acpi_dma_coherency {
	ACPI_DMA_NON_COHERENT,
	ACPI_DMA_COHERENT,
	APCI_DMA_NOT_SUPPORTED = -1,
};

Although, this would need to be defined in the include/linux/acpi.h, and 
will be used also for #ifndef CONFIG_ACPI code to return errors. I was 
not sure if this would be too much. If this is preferred, I'll add this 
back in.

>>
>>   	if (has_acpi_companion(dev)) {
>>   		if (acpi_dev) {
>> @@ -225,7 +225,8 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>>   	if (!has_acpi_companion(dev))
>>   		ACPI_COMPANION_SET(dev, acpi_dev);
>>
>> -	if (acpi_check_dma(acpi_dev, &coherent))
>> +	coherent = acpi_check_dma_coherency(acpi_dev);
>> +	if (coherent != -1)
>
> Like here I'm not sure why -1 is special?

It's just another value to communicate that DMA is not supported. :)

Thanks,
Suravee
>
>>   		arch_setup_dma_ops(dev, 0, 0, NULL, coherent);
>>
>>   	acpi_physnode_link_name(physical_node_name, node_id);
>
> Thanks,
> Rafael
>

Re: [PATCH V2 2/4] ACPI/scan: Clean up acpi_check_dma

[Rafael J. Wysocki]

On Wednesday, August 26, 2015 09:00:23 AM Suravee Suthikulpanit wrote:
> Hi Rafael,
> 
> On 8/26/15 06:48, Rafael J. Wysocki wrote:
> 
> >[...]
> > On Wednesday, August 26, 2015 12:33:27 AM Suravee Suthikulpanit wrote:
> >> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
> >> index b9657af..55cf916 100644
> >> --- a/drivers/acpi/glue.c
> >> +++ b/drivers/acpi/glue.c
> >> @@ -168,7 +168,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
> >>   	struct list_head *physnode_list;
> >>   	unsigned int node_id;
> >>   	int retval = -EINVAL;
> >> -	bool coherent;
> >> +	int coherent;
> >
> > enum, anyone?  With clearly defined values?
> 
> Originally I had defined
> 
> enum acpi_dma_coherency {
> 	ACPI_DMA_NON_COHERENT,
> 	ACPI_DMA_COHERENT,
> 	APCI_DMA_NOT_SUPPORTED = -1,
> };
> 
> Although, this would need to be defined in the include/linux/acpi.h, and 
> will be used also for #ifndef CONFIG_ACPI code to return errors. I was 
> not sure if this would be too much. If this is preferred, I'll add this 
> back in.
> 
> >>
> >>   	if (has_acpi_companion(dev)) {
> >>   		if (acpi_dev) {
> >> @@ -225,7 +225,8 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
> >>   	if (!has_acpi_companion(dev))
> >>   		ACPI_COMPANION_SET(dev, acpi_dev);
> >>
> >> -	if (acpi_check_dma(acpi_dev, &coherent))
> >> +	coherent = acpi_check_dma_coherency(acpi_dev);
> >> +	if (coherent != -1)
> >
> > Like here I'm not sure why -1 is special?
> 
> It's just another value to communicate that DMA is not supported. :)

OK

So maybe use 0/1 for the coherence thing and a proper error code
(-ENOTSUPP seems to be a good candidate) for the "no DMA" case?

Then, if you rename the local variable to something like "ret",
it will be slightly less confusing.

And instead of checking against a specific negative value, you can
simply use "if (stuff < 0)" or "if (stuff >= 0)" to check whether or
not it is supported at all.

Thanks,
Rafael

[PATCH V2 3/4] PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()

[Suravee Suthikulpanit]

This patch move of_pci_dma_configure() to a more generic
pci_dma_configure(), which can be extended by non-OF code (e.g. ACPI).

This has no functional change.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Rob Herring <robh+dt@kernel.org>
CC: Will Deacon <will.deacon@arm.com>
CC: Rafael J. Wysocki <rjw@rjwysocki.net>
CC: Murali Karicheri <m-karicheri2@ti.com>
---
 drivers/of/of_pci.c    | 20 --------------------
 drivers/pci/probe.c    | 27 +++++++++++++++++++++++++--
 include/linux/of_pci.h |  3 ---
 3 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
index 5751dc5..b66ee4e 100644
--- a/drivers/of/of_pci.c
+++ b/drivers/of/of_pci.c
@@ -117,26 +117,6 @@ int of_get_pci_domain_nr(struct device_node *node)
 }
 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
 
-/**
- * of_pci_dma_configure - Setup DMA configuration
- * @dev: ptr to pci_dev struct of the PCI device
- *
- * Function to update PCI devices's DMA configuration using the same
- * info from the OF node of host bridge's parent (if any).
- */
-void of_pci_dma_configure(struct pci_dev *pci_dev)
-{
-	struct device *dev = &pci_dev->dev;
-	struct device *bridge = pci_get_host_bridge_device(pci_dev);
-
-	if (!bridge->parent)
-		return;
-
-	of_dma_configure(dev, bridge->parent->of_node);
-	pci_put_host_bridge_device(bridge);
-}
-EXPORT_SYMBOL_GPL(of_pci_dma_configure);
-
 #if defined(CONFIG_OF_ADDRESS)
 /**
  * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index cefd636..4de6594 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -6,12 +6,14 @@
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/pci.h>
-#include <linux/of_pci.h>
+#include <linux/of_device.h>
 #include <linux/pci_hotplug.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/cpumask.h>
 #include <linux/pci-aspm.h>
+#include <linux/acpi.h>
+#include <linux/property.h>
 #include <asm-generic/pci-bridge.h>
 #include "pci.h"
 
@@ -1544,6 +1546,27 @@ static void pci_init_capabilities(struct pci_dev *dev)
 	pci_enable_acs(dev);
 }
 
+/**
+ * pci_dma_configure - Setup DMA configuration
+ * @dev: ptr to pci_dev struct of the PCI device
+ *
+ * Function to update PCI devices's DMA configuration using the same
+ * info from the OF node of host bridge's parent (if any).
+ */
+static void pci_dma_configure(struct pci_dev *dev)
+{
+	struct device *bridge = pci_get_host_bridge_device(dev);
+
+	if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
+		if (!bridge->parent)
+			return;
+
+		of_dma_configure(&dev->dev, bridge->parent->of_node);
+	}
+
+	pci_put_host_bridge_device(bridge);
+}
+
 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 {
 	int ret;
@@ -1557,7 +1580,7 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 	dev->dev.dma_mask = &dev->dma_mask;
 	dev->dev.dma_parms = &dev->dma_parms;
 	dev->dev.coherent_dma_mask = 0xffffffffull;
-	of_pci_dma_configure(dev);
+	pci_dma_configure(dev);
 
 	pci_set_dma_max_seg_size(dev, 65536);
 	pci_set_dma_seg_boundary(dev, 0xffffffff);
diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
index 29fd3fe..ce0e5ab 100644
--- a/include/linux/of_pci.h
+++ b/include/linux/of_pci.h
@@ -16,7 +16,6 @@ int of_pci_get_devfn(struct device_node *np);
 int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin);
 int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
 int of_get_pci_domain_nr(struct device_node *node);
-void of_pci_dma_configure(struct pci_dev *pci_dev);
 #else
 static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
 {
@@ -51,8 +50,6 @@ of_get_pci_domain_nr(struct device_node *node)
 {
 	return -1;
 }
-
-static inline void of_pci_dma_configure(struct pci_dev *pci_dev) { }
 #endif
 
 #if defined(CONFIG_OF_ADDRESS)
-- 
2.1.0

Re: [PATCH V2 3/4] PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()

[Rob Herring]

On Tue, Aug 25, 2015 at 12:33 PM, Suravee Suthikulpanit
<Suravee.Suthikulpanit@amd.com> wrote:
> This patch move of_pci_dma_configure() to a more generic
> pci_dma_configure(), which can be extended by non-OF code (e.g. ACPI).
>
> This has no functional change.
>
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> CC: Bjorn Helgaas <bhelgaas@google.com>
> CC: Catalin Marinas <catalin.marinas@arm.com>
> CC: Rob Herring <robh+dt@kernel.org>

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

> CC: Will Deacon <will.deacon@arm.com>
> CC: Rafael J. Wysocki <rjw@rjwysocki.net>
> CC: Murali Karicheri <m-karicheri2@ti.com>
> ---
>  drivers/of/of_pci.c    | 20 --------------------
>  drivers/pci/probe.c    | 27 +++++++++++++++++++++++++--
>  include/linux/of_pci.h |  3 ---
>  3 files changed, 25 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> index 5751dc5..b66ee4e 100644
> --- a/drivers/of/of_pci.c
> +++ b/drivers/of/of_pci.c
> @@ -117,26 +117,6 @@ int of_get_pci_domain_nr(struct device_node *node)
>  }
>  EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
>
> -/**
> - * of_pci_dma_configure - Setup DMA configuration
> - * @dev: ptr to pci_dev struct of the PCI device
> - *
> - * Function to update PCI devices's DMA configuration using the same
> - * info from the OF node of host bridge's parent (if any).
> - */
> -void of_pci_dma_configure(struct pci_dev *pci_dev)
> -{
> -       struct device *dev = &pci_dev->dev;
> -       struct device *bridge = pci_get_host_bridge_device(pci_dev);
> -
> -       if (!bridge->parent)
> -               return;
> -
> -       of_dma_configure(dev, bridge->parent->of_node);
> -       pci_put_host_bridge_device(bridge);
> -}
> -EXPORT_SYMBOL_GPL(of_pci_dma_configure);
> -
>  #if defined(CONFIG_OF_ADDRESS)
>  /**
>   * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index cefd636..4de6594 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -6,12 +6,14 @@
>  #include <linux/delay.h>
>  #include <linux/init.h>
>  #include <linux/pci.h>
> -#include <linux/of_pci.h>
> +#include <linux/of_device.h>
>  #include <linux/pci_hotplug.h>
>  #include <linux/slab.h>
>  #include <linux/module.h>
>  #include <linux/cpumask.h>
>  #include <linux/pci-aspm.h>
> +#include <linux/acpi.h>
> +#include <linux/property.h>
>  #include <asm-generic/pci-bridge.h>
>  #include "pci.h"
>
> @@ -1544,6 +1546,27 @@ static void pci_init_capabilities(struct pci_dev *dev)
>         pci_enable_acs(dev);
>  }
>
> +/**
> + * pci_dma_configure - Setup DMA configuration
> + * @dev: ptr to pci_dev struct of the PCI device
> + *
> + * Function to update PCI devices's DMA configuration using the same
> + * info from the OF node of host bridge's parent (if any).
> + */
> +static void pci_dma_configure(struct pci_dev *dev)
> +{
> +       struct device *bridge = pci_get_host_bridge_device(dev);
> +
> +       if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
> +               if (!bridge->parent)
> +                       return;
> +
> +               of_dma_configure(&dev->dev, bridge->parent->of_node);
> +       }
> +
> +       pci_put_host_bridge_device(bridge);
> +}
> +
>  void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
>  {
>         int ret;
> @@ -1557,7 +1580,7 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
>         dev->dev.dma_mask = &dev->dma_mask;
>         dev->dev.dma_parms = &dev->dma_parms;
>         dev->dev.coherent_dma_mask = 0xffffffffull;
> -       of_pci_dma_configure(dev);
> +       pci_dma_configure(dev);
>
>         pci_set_dma_max_seg_size(dev, 65536);
>         pci_set_dma_seg_boundary(dev, 0xffffffff);
> diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
> index 29fd3fe..ce0e5ab 100644
> --- a/include/linux/of_pci.h
> +++ b/include/linux/of_pci.h
> @@ -16,7 +16,6 @@ int of_pci_get_devfn(struct device_node *np);
>  int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin);
>  int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
>  int of_get_pci_domain_nr(struct device_node *node);
> -void of_pci_dma_configure(struct pci_dev *pci_dev);
>  #else
>  static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
>  {
> @@ -51,8 +50,6 @@ of_get_pci_domain_nr(struct device_node *node)
>  {
>         return -1;
>  }
> -
> -static inline void of_pci_dma_configure(struct pci_dev *pci_dev) { }
>  #endif
>
>  #if defined(CONFIG_OF_ADDRESS)
> --
> 2.1.0
>

[PATCH V2 4/4] PCI: ACPI: Add support for PCI device DMA coherency

[Suravee Suthikulpanit]

This patch adds support for setting up PCI device DMA coherency from
ACPI _CCA object that should normally be specified in the DSDT node
of its PCI host bridge.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Rob Herring <robh+dt@kernel.org>
CC: Will Deacon <will.deacon@arm.com>
CC: Rafael J. Wysocki <rjw@rjwysocki.net>
CC: Murali Karicheri <m-karicheri2@ti.com>
---
 drivers/pci/probe.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 4de6594..2fd2a60 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1551,17 +1551,22 @@ static void pci_init_capabilities(struct pci_dev *dev)
  * @dev: ptr to pci_dev struct of the PCI device
  *
  * Function to update PCI devices's DMA configuration using the same
- * info from the OF node of host bridge's parent (if any).
+ * info from the OF node or ACPI node of host bridge's parent (if any).
  */
 static void pci_dma_configure(struct pci_dev *dev)
 {
 	struct device *bridge = pci_get_host_bridge_device(dev);
 
 	if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
-		if (!bridge->parent)
-			return;
-
-		of_dma_configure(&dev->dev, bridge->parent->of_node);
+		if (bridge->parent)
+			of_dma_configure(&dev->dev,
+					 bridge->parent->of_node);
+	} else if (has_acpi_companion(bridge)) {
+		struct acpi_device *adev = to_acpi_node(bridge->fwnode);
+		int coherent = acpi_check_dma_coherency(adev);
+
+		if (-1 != coherent)
+			arch_setup_dma_ops(&dev->dev, 0, 0, NULL, coherent);
 	}
 
 	pci_put_host_bridge_device(bridge);
-- 
2.1.0

Re: [PATCH V2 4/4] PCI: ACPI: Add support for PCI device DMA coherency

[Rafael J. Wysocki]

On Wednesday, August 26, 2015 12:33:29 AM Suravee Suthikulpanit wrote:
> This patch adds support for setting up PCI device DMA coherency from
> ACPI _CCA object that should normally be specified in the DSDT node
> of its PCI host bridge.
> 
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> CC: Bjorn Helgaas <bhelgaas@google.com>
> CC: Catalin Marinas <catalin.marinas@arm.com>
> CC: Rob Herring <robh+dt@kernel.org>
> CC: Will Deacon <will.deacon@arm.com>
> CC: Rafael J. Wysocki <rjw@rjwysocki.net>
> CC: Murali Karicheri <m-karicheri2@ti.com>
> ---
>  drivers/pci/probe.c | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 4de6594..2fd2a60 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1551,17 +1551,22 @@ static void pci_init_capabilities(struct pci_dev *dev)
>   * @dev: ptr to pci_dev struct of the PCI device
>   *
>   * Function to update PCI devices's DMA configuration using the same
> - * info from the OF node of host bridge's parent (if any).
> + * info from the OF node or ACPI node of host bridge's parent (if any).
>   */
>  static void pci_dma_configure(struct pci_dev *dev)
>  {
>  	struct device *bridge = pci_get_host_bridge_device(dev);
>  
>  	if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
> -		if (!bridge->parent)
> -			return;
> -
> -		of_dma_configure(&dev->dev, bridge->parent->of_node);
> +		if (bridge->parent)
> +			of_dma_configure(&dev->dev,
> +					 bridge->parent->of_node);
> +	} else if (has_acpi_companion(bridge)) {
> +		struct acpi_device *adev = to_acpi_node(bridge->fwnode);
> +		int coherent = acpi_check_dma_coherency(adev);
> +
> +		if (-1 != coherent)

The ordering of this check is somewhat unusual.


> +			arch_setup_dma_ops(&dev->dev, 0, 0, NULL, coherent);
>  	}
>  
>  	pci_put_host_bridge_device(bridge);
> 

Thanks,
Rafael

Re: [PATCH V2 4/4] PCI: ACPI: Add support for PCI device DMA coherency

[Suravee Suthikulpanit]

Hi Rafael,

On 8/26/15 06:48, Rafael J. Wysocki wrote:
> On Wednesday, August 26, 2015 12:33:29 AM Suravee Suthikulpanit wrote:
>> This patch adds support for setting up PCI device DMA coherency from
>> ACPI _CCA object that should normally be specified in the DSDT node
>> of its PCI host bridge.
>>
>> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
>> CC: Bjorn Helgaas <bhelgaas@google.com>
>> CC: Catalin Marinas <catalin.marinas@arm.com>
>> CC: Rob Herring <robh+dt@kernel.org>
>> CC: Will Deacon <will.deacon@arm.com>
>> CC: Rafael J. Wysocki <rjw@rjwysocki.net>
>> CC: Murali Karicheri <m-karicheri2@ti.com>
>> ---
>>   drivers/pci/probe.c | 15 ++++++++++-----
>>   1 file changed, 10 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
>> index 4de6594..2fd2a60 100644
>> --- a/drivers/pci/probe.c
>> +++ b/drivers/pci/probe.c
>> @@ -1551,17 +1551,22 @@ static void pci_init_capabilities(struct pci_dev *dev)
>>    * @dev: ptr to pci_dev struct of the PCI device
>>    *
>>    * Function to update PCI devices's DMA configuration using the same
>> - * info from the OF node of host bridge's parent (if any).
>> + * info from the OF node or ACPI node of host bridge's parent (if any).
>>    */
>>   static void pci_dma_configure(struct pci_dev *dev)
>>   {
>>   	struct device *bridge = pci_get_host_bridge_device(dev);
>>
>>   	if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
>> -		if (!bridge->parent)
>> -			return;
>> -
>> -		of_dma_configure(&dev->dev, bridge->parent->of_node);
>> +		if (bridge->parent)
>> +			of_dma_configure(&dev->dev,
>> +					 bridge->parent->of_node);
>> +	} else if (has_acpi_companion(bridge)) {
>> +		struct acpi_device *adev = to_acpi_node(bridge->fwnode);
>> +		int coherent = acpi_check_dma_coherency(adev);
>> +
>> +		if (-1 != coherent)
>
> The ordering of this check is somewhat unusual.

I'll fix this.

Thanks,
Suravee

Re: [PATCH V2 0/4] PCI: ACPI: Setting up DMA coherency for PCI device from _CCA attribute

[Arnd Bergmann]

On Wednesday 26 August 2015 00:33:25 Suravee Suthikulpanit wrote:
> This patch adds support to setup DMA coherency for PCI device using
> the ACPI _CCA attribute. According to the ACPI spec, the _CCA attribute
> is required for ARM64. Therefore, this patch is a pre-req for ACPI PCI
> support for ARM64 which is currently in development.
> 
> Also, this should not affect other architectures that does not define 
> CONFIG_ACPI_CCA_REQUIRED, since the default value is coherent.
> 

We only support ACPI on SBSA compliant platforms, and SBSA mandates
cache-coherent PCI, so I don't think this is actually needed,
just use coherent all the time and do WARN_ON(!CCA) to catch people
that try to incorrectly use ACPI on a non-SBSA platform.

	Arnd

Re: [PATCH V2 0/4] PCI: ACPI: Setting up DMA coherency for PCI device from _CCA attribute

[Suravee Suthikulpanit]

Hi Arnd,

On 8/26/15 01:48, Arnd Bergmann wrote:
> On Wednesday 26 August 2015 00:33:25 Suravee Suthikulpanit wrote:
>> This patch adds support to setup DMA coherency for PCI device using
>> the ACPI _CCA attribute. According to the ACPI spec, the _CCA attribute
>> is required for ARM64. Therefore, this patch is a pre-req for ACPI PCI
>> support for ARM64 which is currently in development.
>>
>> Also, this should not affect other architectures that does not define
>> CONFIG_ACPI_CCA_REQUIRED, since the default value is coherent.
>>
>
> We only support ACPI on SBSA compliant platforms, and SBSA mandates
> cache-coherent PCI, so I don't think this is actually needed,
> just use coherent all the time and do WARN_ON(!CCA) to catch people
> that try to incorrectly use ACPI on a non-SBSA platform.
>
> 	Arnd

Thanks for pointing out. The CONFIG_ACPI_CCA_REQUIRED is already existed 
and selected in arch/arm64/Kconfig, and used for both PCI and non-PCI 
devices. I am not adding anything specific for the PCI case.

Although, I think WARN_ON(!CCA) when it is required is a good idea. I'll 
find a proper place for it.

Thanks,
Suravee.

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