Re: [PATCH v5 06/14] drivers: acpi: implement acpi_dma_configure

2016-09-13 Thread Lorenzo Pieralisi 
On Tue, Sep 13, 2016 at 03:41:06PM +0100, Robin Murphy wrote:
> On 09/09/16 15:23, 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.
> > 
> > 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]
> > 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 | 24 
> >  drivers/pci/probe.c |  3 +--
> >  include/acpi/acpi_bus.h |  2 ++
> >  include/linux/acpi.h|  5 +
> >  5 files changed, 34 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);

Here's the call for non-PCI devices ;-)

> > 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 e878fc7..9614232 100644
> > --- a/drivers/acpi/scan.c
> > +++ b/drivers/acpi/scan.c
> > @@ -1370,6 +1370,30 @@ 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)
> > +{
> > +   /*
> > +* 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);
> 
> This looks a bit hairy - if we're setting up the DMA configuration at
> this point can we really always rely on the device already having a
> valid DMA mask? I think it would make sense to at least check, and apply
> the standard default 32-bit mask  if not.

That's a good point, but we would be changing the x86/IA64 probing path
if we do what you suggest; so I think you are right and it should be a
safe change to make but I still need to make sure we do not break
anything in the process.

> > +}
> > +
> > +/**
> > + * 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);
> > +}
> 
> As touched upon in the dwc-usb3 thread, is it worth exporting these for
> the benefit of modular bus/glue code, to match of_dma_configure()?

I think yes, I will do.

> >  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 93f280d..e96d482 100644
> > --- a/drivers/pci/probe.c
> > +++ b/drivers/pci/probe.c
> > @@ -1734,8 +1734,7 @@ static void pci_dma_configure(struct pci_dev *dev)
> > if (attr == DEV_DMA_NOT_SUPPORTED)
> > dev_warn(>dev, "DMA not supported.\n");
> > else
> > -

Re: [PATCH v5 06/14] drivers: acpi: implement acpi_dma_configure

2016-09-13 Thread Robin Murphy 
On 09/09/16 15:23, 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.
> 
> 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]
> 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 | 24 
>  drivers/pci/probe.c |  3 +--
>  include/acpi/acpi_bus.h |  2 ++
>  include/linux/acpi.h|  5 +
>  5 files changed, 34 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 e878fc7..9614232 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1370,6 +1370,30 @@ 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)
> +{
> + /*
> +  * 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);

This looks a bit hairy - if we're setting up the DMA configuration at
this point can we really always rely on the device already having a
valid DMA mask? I think it would make sense to at least check, and apply
the standard default 32-bit mask  if not.

> +}
> +
> +/**
> + * 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);
> +}

As touched upon in the dwc-usb3 thread, is it worth exporting these for
the benefit of modular bus/glue code, to match of_dma_configure()?

> +
>  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 93f280d..e96d482 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1734,8 +1734,7 @@ 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);
>   }

What about non-PCI stuff? I see there's at least an
acpi_create_platform_device() which I'd also kind of expect to see as a
caller (which indeed might also tie in with the aforementioned default
mask initialisation).

Robin.

>  
>   pci_put_host_bridge_device(bridge);
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index c1a524d..4242c31

[PATCH v5 06/14] drivers: acpi: implement acpi_dma_configure

2016-09-09 Thread 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.

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]
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 | 24 
 drivers/pci/probe.c |  3 +--
 include/acpi/acpi_bus.h |  2 ++
 include/linux/acpi.h|  5 +
 5 files changed, 34 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 e878fc7..9614232 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1370,6 +1370,30 @@ 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)
+{
+   /*
+* 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);
+}
+
+/**
+ * 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);
+}
+
 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 93f280d..e96d482 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1734,8 +1734,7 @@ 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);
}
 
pci_put_host_bridge_device(bridge);
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index c1a524d..4242c31 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -573,6 +573,8 @@ struct acpi_pci_root {
 
 bool acpi_dma_supported(struct acpi_device *adev);
 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev);
+void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr);
+void acpi_dma_deconfigure(struct device *dev);
 
 struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
   u64 address, bool check_children);
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index c5eaf2f..05d4e48 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -729,6 +729,11 @@ static inline enum dev_dma_attr acpi_get_dma_attr(struct 
acpi_device *adev)
return DEV_DMA_NOT_SUPPORTED;
 }
 
+static inline void acpi_dma_configure(struct