RE: [PATCH v3 1/2] dma-mapping: move dma configuration to bus infrastructure

[Nipun Gupta]

> -Original Message-
> From: Christoph Hellwig [mailto:h...@lst.de]
> Sent: Monday, April 23, 2018 6:27 PM
> To: Nipun Gupta <nipun.gu...@nxp.com>
> Cc: robin.mur...@arm.com; h...@lst.de; li...@armlinux.org.uk;
> gre...@linuxfoundation.org; m.szyprow...@samsung.com;
> bhelg...@google.com; zaj...@gmail.com; andy.gr...@linaro.org;
> david.br...@linaro.org; dan.j.willi...@intel.com; vinod.k...@intel.com;
> thierry.red...@gmail.com; robh...@kernel.org; frowand.l...@gmail.com;
> jarkko.sakki...@linux.intel.com; rafael.j.wyso...@intel.com;
> dmitry.torok...@gmail.com; jo...@kernel.org; msucha...@suse.de; linux-
> ker...@vger.kernel.org; io...@lists.linux-foundation.org; linux-
> wirel...@vger.kernel.org; linux-arm-...@vger.kernel.org; linux-
> s...@vger.kernel.org; dmaeng...@vger.kernel.org; dri-
> de...@lists.freedesktop.org; linux-te...@vger.kernel.org;
> devicet...@vger.kernel.org; linux-...@vger.kernel.org; Bharat Bhushan
> <bharat.bhus...@nxp.com>; Leo Li <leoyang...@nxp.com>
> Subject: Re: [PATCH v3 1/2] dma-mapping: move dma configuration to bus
> infrastructure
> 
> Can you resend your changes against Linux 4.17-rc2?  There are a lot
> of conflicts as-is.

Sure.. I will send it soon..

Regards,
Nipun
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Re: [PATCH v3 1/2] dma-mapping: move dma configuration to bus infrastructure

[Christoph Hellwig]

Can you resend your changes against Linux 4.17-rc2?  There are a lot
of conflicts as-is.
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Re: [PATCH v3 1/2] dma-mapping: move dma configuration to bus infrastructure

[Christoph Hellwig]

On Tue, Apr 10, 2018 at 02:20:41PM -0500, Bjorn Helgaas wrote:
> I assume you'll merge this via some non-PCI tree.  Let me know if you
> need anything else from me.

I'll take it through the dma-mapping tree, so you should be fine.
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Re: [PATCH v3 1/2] dma-mapping: move dma configuration to bus infrastructure

[Bjorn Helgaas]

On Fri, Mar 30, 2018 at 01:24:44PM +0530, Nipun Gupta wrote:
> It is bus specific aspect to map a given device on the bus and
> relevant firmware description of its DMA configuration.
> So, this change introduces 'dma_configure' as bus callback
> giving flexibility to busses for implementing its own dma
> configuration function.
> 
> The change eases the addition of new busses w.r.t. adding the dma
> configuration functionality.
> 
> This patch also updates the PCI, Platform, ACPI and host1x bus to
> use new introduced callbacks.

s/dma/DMA/ consistently above.

> Suggested-by: Christoph Hellwig 
> Signed-off-by: Nipun Gupta 
> Reviewed-by: Greg Kroah-Hartman 

Acked-by: Bjorn Helgaas   # PCI parts

I assume you'll merge this via some non-PCI tree.  Let me know if you
need anything else from me.

> ---
>  - The patches are based on the comments on:
>https://patchwork.kernel.org/patch/10259087/
> 
> Changes in v2:
>   - Do not have dma_deconfigure callback
>   - Have '/dma_common_configure/' API to provide a common DMA
> configuration which can be used by busses if it suits them.
>   - Platform and ACPI bus to use '/dma_common_configure/' in
> '/dma_configure/' callback.
>   - Updated commit message
>   - Updated pci_dma_configure API with changes suggested by Robin
> 
> Changes in v3
>   - Move dma_common_configure() within platform_dma_configure() and
> reuse platofrm_dma_configure() for AMBA bus too
>   - Declare 'attr' in pci_dma_configure() inside the else statement
> where it is used.
> 
>  drivers/amba/bus.c  |  4 
>  drivers/base/dma-mapping.c  | 31 ---
>  drivers/base/platform.c | 17 +
>  drivers/gpu/host1x/bus.c|  8 
>  drivers/pci/pci-driver.c| 32 
>  include/linux/device.h  |  4 
>  include/linux/platform_device.h |  2 ++
>  7 files changed, 71 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
> index 594c228..867dc2b 100644
> --- a/drivers/amba/bus.c
> +++ b/drivers/amba/bus.c
> @@ -20,6 +20,7 @@
>  #include 
>  #include 
>  #include 
> +#include 
>  
>  #include 
>  
> @@ -188,12 +189,15 @@ static int amba_pm_runtime_resume(struct device *dev)
>  /*
>   * Primecells are part of the Advanced Microcontroller Bus Architecture,
>   * so we call the bus "amba".
> + * DMA configuration for platform and AMBA bus is same. So here we reuse
> + * platform's DMA config routine.
>   */
>  struct bus_type amba_bustype = {
>   .name   = "amba",
>   .dev_groups = amba_dev_groups,
>   .match  = amba_match,
>   .uevent = amba_uevent,
> + .dma_configure  = platform_dma_configure,
>   .pm = _pm,
>   .force_dma  = true,
>  };
> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> index 3b11835..fdc1502 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -331,36 +331,13 @@ void dma_common_free_remap(void *cpu_addr, size_t size, 
> unsigned long vm_flags)
>  #endif
>  
>  /*
> - * Common configuration to enable DMA API use for a device
> + * enables DMA API use for a device
>   */
> -#include 
> -
>  int dma_configure(struct device *dev)
>  {
> - struct device *bridge = NULL, *dma_dev = dev;
> - enum dev_dma_attr attr;
> - int ret = 0;
> -
> - if (dev_is_pci(dev)) {
> - bridge = pci_get_host_bridge_device(to_pci_dev(dev));
> - dma_dev = bridge;
> - if (IS_ENABLED(CONFIG_OF) && dma_dev->parent &&
> - dma_dev->parent->of_node)
> - dma_dev = dma_dev->parent;
> - }
> -
> - if (dma_dev->of_node) {
> - ret = of_dma_configure(dev, dma_dev->of_node);
> - } else if (has_acpi_companion(dma_dev)) {
> - attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode));
> - if (attr != DEV_DMA_NOT_SUPPORTED)
> - ret = acpi_dma_configure(dev, attr);
> - }
> -
> - if (bridge)
> - pci_put_host_bridge_device(bridge);
> -
> - return ret;
> + if (dev->bus->dma_configure)
> + return dev->bus->dma_configure(dev);
> + return 0;
>  }
>  
>  void dma_deconfigure(struct device *dev)
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index f1bf7b3..72fdbf6 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -1130,6 +1130,22 @@ int platform_pm_restore(struct device *dev)
>  
>  #endif /* CONFIG_HIBERNATE_CALLBACKS */
>  
> +int platform_dma_configure(struct device *dev)
> +{
> + enum dev_dma_attr attr;
> + int ret = 0;
> +
> + if (dev->of_node) {
> + ret = of_dma_configure(dev, dev->of_node);
> + } else if (has_acpi_companion(dev)) {
> + attr = 

[PATCH v3 1/2] dma-mapping: move dma configuration to bus infrastructure

[Nipun Gupta]

It is bus specific aspect to map a given device on the bus and
relevant firmware description of its DMA configuration.
So, this change introduces 'dma_configure' as bus callback
giving flexibility to busses for implementing its own dma
configuration function.

The change eases the addition of new busses w.r.t. adding the dma
configuration functionality.

This patch also updates the PCI, Platform, ACPI and host1x bus to
use new introduced callbacks.

Suggested-by: Christoph Hellwig 
Signed-off-by: Nipun Gupta 
Reviewed-by: Greg Kroah-Hartman 
---
 - The patches are based on the comments on:
   https://patchwork.kernel.org/patch/10259087/

Changes in v2:
  - Do not have dma_deconfigure callback
  - Have '/dma_common_configure/' API to provide a common DMA
configuration which can be used by busses if it suits them.
  - Platform and ACPI bus to use '/dma_common_configure/' in
'/dma_configure/' callback.
  - Updated commit message
  - Updated pci_dma_configure API with changes suggested by Robin

Changes in v3
  - Move dma_common_configure() within platform_dma_configure() and
reuse platofrm_dma_configure() for AMBA bus too
  - Declare 'attr' in pci_dma_configure() inside the else statement
where it is used.

 drivers/amba/bus.c  |  4 
 drivers/base/dma-mapping.c  | 31 ---
 drivers/base/platform.c | 17 +
 drivers/gpu/host1x/bus.c|  8 
 drivers/pci/pci-driver.c| 32 
 include/linux/device.h  |  4 
 include/linux/platform_device.h |  2 ++
 7 files changed, 71 insertions(+), 27 deletions(-)

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 594c228..867dc2b 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -20,6 +20,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include 
 
@@ -188,12 +189,15 @@ static int amba_pm_runtime_resume(struct device *dev)
 /*
  * Primecells are part of the Advanced Microcontroller Bus Architecture,
  * so we call the bus "amba".
+ * DMA configuration for platform and AMBA bus is same. So here we reuse
+ * platform's DMA config routine.
  */
 struct bus_type amba_bustype = {
.name   = "amba",
.dev_groups = amba_dev_groups,
.match  = amba_match,
.uevent = amba_uevent,
+   .dma_configure  = platform_dma_configure,
.pm = _pm,
.force_dma  = true,
 };
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 3b11835..fdc1502 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -331,36 +331,13 @@ void dma_common_free_remap(void *cpu_addr, size_t size, 
unsigned long vm_flags)
 #endif
 
 /*
- * Common configuration to enable DMA API use for a device
+ * enables DMA API use for a device
  */
-#include 
-
 int dma_configure(struct device *dev)
 {
-   struct device *bridge = NULL, *dma_dev = dev;
-   enum dev_dma_attr attr;
-   int ret = 0;
-
-   if (dev_is_pci(dev)) {
-   bridge = pci_get_host_bridge_device(to_pci_dev(dev));
-   dma_dev = bridge;
-   if (IS_ENABLED(CONFIG_OF) && dma_dev->parent &&
-   dma_dev->parent->of_node)
-   dma_dev = dma_dev->parent;
-   }
-
-   if (dma_dev->of_node) {
-   ret = of_dma_configure(dev, dma_dev->of_node);
-   } else if (has_acpi_companion(dma_dev)) {
-   attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode));
-   if (attr != DEV_DMA_NOT_SUPPORTED)
-   ret = acpi_dma_configure(dev, attr);
-   }
-
-   if (bridge)
-   pci_put_host_bridge_device(bridge);
-
-   return ret;
+   if (dev->bus->dma_configure)
+   return dev->bus->dma_configure(dev);
+   return 0;
 }
 
 void dma_deconfigure(struct device *dev)
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index f1bf7b3..72fdbf6 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -1130,6 +1130,22 @@ int platform_pm_restore(struct device *dev)
 
 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 
+int platform_dma_configure(struct device *dev)
+{
+   enum dev_dma_attr attr;
+   int ret = 0;
+
+   if (dev->of_node) {
+   ret = of_dma_configure(dev, dev->of_node);
+   } else if (has_acpi_companion(dev)) {
+   attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
+   if (attr != DEV_DMA_NOT_SUPPORTED)
+   ret = acpi_dma_configure(dev, attr);
+   }
+
+   return ret;
+}
+
 static const struct dev_pm_ops platform_dev_pm_ops = {
.runtime_suspend = pm_generic_runtime_suspend,
.runtime_resume = pm_generic_runtime_resume,
@@ -1141,6 +1157,7 @@ struct bus_type platform_bus_type = {
.dev_groups = platform_dev_groups,