Re: [PATCH v7 07/16] drivers: acpi: implement acpi_dma_configure

[Rafael J. Wysocki]

On Wed, Nov 9, 2016 at 3:19 PM, Lorenzo Pieralisi
 wrote:
> On DT based systems, the of_dma_configure() API implements DMA
> configuration for a given device. On ACPI systems an API equivalent to
> of_dma_configure() is missing which implies that it is currently not
> possible to set-up DMA operations for devices through the ACPI generic
> kernel layer.
>
> This patch fills the gap by introducing acpi_dma_configure/deconfigure()
> calls that for now are just wrappers around arch_setup_dma_ops() and
> arch_teardown_dma_ops() and also updates ACPI and PCI core code to use
> the newly introduced acpi_dma_configure/acpi_dma_deconfigure functions.
>
> Since acpi_dma_configure() is used to configure DMA operations, the
> function initializes the dma/coherent_dma masks to sane default values
> if the current masks are uninitialized (also to keep the default values
> consistent with DT systems) to make sure the device has a complete
> default DMA set-up.
>
> The DMA range size passed to arch_setup_dma_ops() is sized according
> to the device coherent_dma_mask (starting at address 0x0), mirroring the
> DT probing path behaviour when a dma-ranges property is not provided
> for the device being probed; this changes the current arch_setup_dma_ops()
> call parameters in the ACPI probing case, but since arch_setup_dma_ops()
> is a NOP on all architectures but ARM/ARM64 this patch does not change
> the current kernel behaviour on them.
>
> Signed-off-by: Lorenzo Pieralisi 
> Acked-by: Bjorn Helgaas  [pci]
> Tested-by: Hanjun Guo 
> Tested-by: Tomasz Nowicki 
> Cc: Bjorn Helgaas 
> Cc: Robin Murphy 
> Cc: Tomasz Nowicki 
> Cc: Joerg Roedel 
> Cc: "Rafael J. Wysocki" 

LGTM

Acked-by: Rafael J. Wysocki 
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Re: [PATCH v7 07/16] drivers: acpi: implement acpi_dma_configure

[Robin Murphy]

On 09/11/16 14:19, Lorenzo Pieralisi wrote:
> On DT based systems, the of_dma_configure() API implements DMA
> configuration for a given device. On ACPI systems an API equivalent to
> of_dma_configure() is missing which implies that it is currently not
> possible to set-up DMA operations for devices through the ACPI generic
> kernel layer.
> 
> This patch fills the gap by introducing acpi_dma_configure/deconfigure()
> calls that for now are just wrappers around arch_setup_dma_ops() and
> arch_teardown_dma_ops() and also updates ACPI and PCI core code to use
> the newly introduced acpi_dma_configure/acpi_dma_deconfigure functions.
> 
> Since acpi_dma_configure() is used to configure DMA operations, the
> function initializes the dma/coherent_dma masks to sane default values
> if the current masks are uninitialized (also to keep the default values
> consistent with DT systems) to make sure the device has a complete
> default DMA set-up.
> 
> The DMA range size passed to arch_setup_dma_ops() is sized according
> to the device coherent_dma_mask (starting at address 0x0), mirroring the
> DT probing path behaviour when a dma-ranges property is not provided
> for the device being probed; this changes the current arch_setup_dma_ops()
> call parameters in the ACPI probing case, but since arch_setup_dma_ops()
> is a NOP on all architectures but ARM/ARM64 this patch does not change
> the current kernel behaviour on them.
> 
> Signed-off-by: Lorenzo Pieralisi 
> Acked-by: Bjorn Helgaas  [pci]
> Tested-by: Hanjun Guo 
> Tested-by: Tomasz Nowicki 
> Cc: Bjorn Helgaas 
> Cc: Robin Murphy 
> Cc: Tomasz Nowicki 
> Cc: Joerg Roedel 
> Cc: "Rafael J. Wysocki" 
> ---
>  drivers/acpi/glue.c |  4 ++--
>  drivers/acpi/scan.c | 40 
>  drivers/pci/probe.c |  3 +--
>  include/acpi/acpi_bus.h |  2 ++
>  include/linux/acpi.h|  5 +
>  5 files changed, 50 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
> index 5ea5dc2..f8d6564 100644
> --- a/drivers/acpi/glue.c
> +++ b/drivers/acpi/glue.c
> @@ -227,8 +227,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device 
> *acpi_dev)
>  
>   attr = acpi_get_dma_attr(acpi_dev);
>   if (attr != DEV_DMA_NOT_SUPPORTED)
> - arch_setup_dma_ops(dev, 0, 0, NULL,
> -attr == DEV_DMA_COHERENT);
> + acpi_dma_configure(dev, attr);
>  
>   acpi_physnode_link_name(physical_node_name, node_id);
>   retval = sysfs_create_link(_dev->dev.kobj, >kobj,
> @@ -251,6 +250,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device 
> *acpi_dev)
>   return 0;
>  
>   err:
> + acpi_dma_deconfigure(dev);
>   ACPI_COMPANION_SET(dev, NULL);
>   put_device(dev);
>   put_device(_dev->dev);
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 035ac64..694e0b6 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1370,6 +1370,46 @@ enum dev_dma_attr acpi_get_dma_attr(struct acpi_device 
> *adev)
>   return DEV_DMA_NON_COHERENT;
>  }
>  
> +/**
> + * acpi_dma_configure - Set-up DMA configuration for the device.
> + * @dev: The pointer to the device
> + * @attr: device dma attributes
> + */
> +void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
> +{
> + /*
> +  * Set default coherent_dma_mask to 32 bit.  Drivers are expected to
> +  * setup the correct supported mask.
> +  */
> + if (!dev->coherent_dma_mask)
> + dev->coherent_dma_mask = DMA_BIT_MASK(32);
> +
> + /*
> +  * Set it to coherent_dma_mask by default if the architecture
> +  * code has not set it.
> +  */
> + if (!dev->dma_mask)
> + dev->dma_mask = >coherent_dma_mask;
> +
> + /*
> +  * Assume dma valid range starts at 0 and covers the whole
> +  * coherent_dma_mask.
> +  */
> + arch_setup_dma_ops(dev, 0, dev->coherent_dma_mask + 1, NULL,
> +attr == DEV_DMA_COHERENT);
> +}
> +EXPORT_SYMBOL_GPL(acpi_dma_configure);
> +
> +/**
> + * acpi_dma_deconfigure - Tear-down DMA configuration for the device.
> + * @dev: The pointer to the device
> + */
> +void acpi_dma_deconfigure(struct device *dev)
> +{
> + arch_teardown_dma_ops(dev);
> +}
> +EXPORT_SYMBOL_GPL(acpi_dma_deconfigure);
> +
>  static void acpi_init_coherency(struct acpi_device *adev)
>  {
>   unsigned long long cca = 0;
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index ab00267..c29e07a 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1738,8 +1738,7 @@ static void pci_dma_configure(struct pci_dev *dev)
>   if (attr == DEV_DMA_NOT_SUPPORTED)
>   dev_warn(>dev, "DMA not supported.\n");

If we're going 

[PATCH v7 07/16] drivers: acpi: implement acpi_dma_configure

[Lorenzo Pieralisi]

On DT based systems, the of_dma_configure() API implements DMA
configuration for a given device. On ACPI systems an API equivalent to
of_dma_configure() is missing which implies that it is currently not
possible to set-up DMA operations for devices through the ACPI generic
kernel layer.

This patch fills the gap by introducing acpi_dma_configure/deconfigure()
calls that for now are just wrappers around arch_setup_dma_ops() and
arch_teardown_dma_ops() and also updates ACPI and PCI core code to use
the newly introduced acpi_dma_configure/acpi_dma_deconfigure functions.

Since acpi_dma_configure() is used to configure DMA operations, the
function initializes the dma/coherent_dma masks to sane default values
if the current masks are uninitialized (also to keep the default values
consistent with DT systems) to make sure the device has a complete
default DMA set-up.

The DMA range size passed to arch_setup_dma_ops() is sized according
to the device coherent_dma_mask (starting at address 0x0), mirroring the
DT probing path behaviour when a dma-ranges property is not provided
for the device being probed; this changes the current arch_setup_dma_ops()
call parameters in the ACPI probing case, but since arch_setup_dma_ops()
is a NOP on all architectures but ARM/ARM64 this patch does not change
the current kernel behaviour on them.

Signed-off-by: Lorenzo Pieralisi 
Acked-by: Bjorn Helgaas  [pci]
Tested-by: Hanjun Guo 
Tested-by: Tomasz Nowicki 
Cc: Bjorn Helgaas 
Cc: Robin Murphy 
Cc: Tomasz Nowicki 
Cc: Joerg Roedel 
Cc: "Rafael J. Wysocki" 
---
 drivers/acpi/glue.c |  4 ++--
 drivers/acpi/scan.c | 40 
 drivers/pci/probe.c |  3 +--
 include/acpi/acpi_bus.h |  2 ++
 include/linux/acpi.h|  5 +
 5 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index 5ea5dc2..f8d6564 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -227,8 +227,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device 
*acpi_dev)
 
attr = acpi_get_dma_attr(acpi_dev);
if (attr != DEV_DMA_NOT_SUPPORTED)
-   arch_setup_dma_ops(dev, 0, 0, NULL,
-  attr == DEV_DMA_COHERENT);
+   acpi_dma_configure(dev, attr);
 
acpi_physnode_link_name(physical_node_name, node_id);
retval = sysfs_create_link(_dev->dev.kobj, >kobj,
@@ -251,6 +250,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device 
*acpi_dev)
return 0;
 
  err:
+   acpi_dma_deconfigure(dev);
ACPI_COMPANION_SET(dev, NULL);
put_device(dev);
put_device(_dev->dev);
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 035ac64..694e0b6 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1370,6 +1370,46 @@ enum dev_dma_attr acpi_get_dma_attr(struct acpi_device 
*adev)
return DEV_DMA_NON_COHERENT;
 }
 
+/**
+ * acpi_dma_configure - Set-up DMA configuration for the device.
+ * @dev: The pointer to the device
+ * @attr: device dma attributes
+ */
+void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
+{
+   /*
+* Set default coherent_dma_mask to 32 bit.  Drivers are expected to
+* setup the correct supported mask.
+*/
+   if (!dev->coherent_dma_mask)
+   dev->coherent_dma_mask = DMA_BIT_MASK(32);
+
+   /*
+* Set it to coherent_dma_mask by default if the architecture
+* code has not set it.
+*/
+   if (!dev->dma_mask)
+   dev->dma_mask = >coherent_dma_mask;
+
+   /*
+* Assume dma valid range starts at 0 and covers the whole
+* coherent_dma_mask.
+*/
+   arch_setup_dma_ops(dev, 0, dev->coherent_dma_mask + 1, NULL,
+  attr == DEV_DMA_COHERENT);
+}
+EXPORT_SYMBOL_GPL(acpi_dma_configure);
+
+/**
+ * acpi_dma_deconfigure - Tear-down DMA configuration for the device.
+ * @dev: The pointer to the device
+ */
+void acpi_dma_deconfigure(struct device *dev)
+{
+   arch_teardown_dma_ops(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_dma_deconfigure);
+
 static void acpi_init_coherency(struct acpi_device *adev)
 {
unsigned long long cca = 0;
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ab00267..c29e07a 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1738,8 +1738,7 @@ static void pci_dma_configure(struct pci_dev *dev)
if (attr == DEV_DMA_NOT_SUPPORTED)
dev_warn(>dev, "DMA not supported.\n");
else
-   arch_setup_dma_ops(>dev, 0, 0, NULL,
-  attr == DEV_DMA_COHERENT);
+   acpi_dma_configure(>dev, attr);
}