Hi Marek,
Marek Szyprowski m.szyprowski@samsung.com wrote @ Mon, 24 Sep 2012 13:14:51 +0200:
Hello,
On Monday, September 24, 2012 11:45 AM Hiroshi Doyu wrote:
On Mon, 24 Sep 2012 11:28:01 +0200 James Bottomley James.Bottomley@HansenPartnership.com wrote:
On Mon, 2012-09-24 at 12:04 +0300, Hiroshi Doyu wrote:
diff --git a/drivers/base/platform.c b/drivers/base/platform.c index a1a7225..9eae3be 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -21,6 +21,8 @@ #include <linux/slab.h> #include <linux/pm_runtime.h>
+#include <asm/dma-iommu.h>
#include "base.h"
#define to_platform_driver(drv) (container_of((drv), struct platform_driver, \ @@ -305,8 +307,19 @@ int platform_device_add(struct platform_device *pdev) dev_name(&pdev->dev), dev_name(pdev->dev.parent));
ret = device_add(&pdev->dev);
if (ret == 0)return ret;
if (ret)goto failed;+#ifdef CONFIG_PLATFORM_ENABLE_IOMMU
if (platform_bus_type.map && !pdev->dev.archdata.mapping) {ret = arm_iommu_attach_device(&pdev->dev,platform_bus_type.map);if (ret)goto failed;This is horrible ... you're adding an architecture specific callback into our generic code; that's really a no-no. If the concept of CONFIG_PLATFORM_ENABE_IOMMU is useful to more than just arm, then this could become a generic callback.
As mentioned in the original, this is a heck to explain what is needed. I am looking for some generic solution for how to specify IOMMU info for each platform devices. I'm guessing that some other SoC may have the similar requirements on the above. As you mentioned, this solution should be a generic, not arch specific.
Please read more about bus notifiers. IMHO a good example is provided in the following thread: http://www.mail-archive.com/linux-samsung-soc@vger.kernel.org/msg12238.html
This bus notifier seems enough flexible to afford the variation of IOMMU map info, like Tegra ASID, which could be platform-specific, and the other could be common too. There's already iommu_bus_notifier too. I'll try to implement something base on this.
Thanks for the good info.