On Fri, Dec 28, 2012 at 09:53:47AM +0530, Prathyush K wrote:
On Thu, Dec 27, 2012 at 7:45 PM, Marek Szyprowski m.szyprowski@samsung.comwrote:
Hello,
On 12/27/2012 8:14 AM, Prathyush K wrote:
This patch adds EXPORT_SYMBOL calls to the three arm iommu functions - arm_iommu_create_mapping, arm_iommu_free_mapping and arm_iommu_attach_device. These functions can now be called from dynamic modules.
Could You describe a bit more why those functions might be needed by dynamic modules?
Hi Marek,
We are adding iommu support to exynos gsc and s5p-mfc. And these two drivers need to be built as modules to improve boot time.
We're calling these three functions from inside these drivers: e.g. mapping = arm_iommu_create_mapping(&platform_bus_type, 0x20000000, SZ_256M, 4); arm_iommu_attach_device(mdev, mapping);
The driver shouldn't have to call these low-level functions directly, something's wrong if you need that.
How is the DMA address management different here from other system/io mmus? is that 256M window a hardware restriction?
-Olof