Hi Marek,
Add initial proof of concept implementation of DMA-mapping API for devices that have IOMMU support. Right now only dma_alloc_coherent, dma_free_coherent and dma_mmap_coherent functions are supported.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com
...
diff --git a/arch/arm/include/asm/dma-iommu.h b/arch/arm/include/asm/dma-iommu.h new file mode 100644 index 0000000..c246ff3 --- /dev/null +++ b/arch/arm/include/asm/dma-iommu.h
...
+int __init arm_iommu_assign_device(struct device *dev, dma_addr_t base, dma_addr_t size);
__init causes a panic if the iommu is assigned after boot.
In OMAP3 the iommu driver controls isp and dsp address spaces, it is loaded until any of those 2 drivers is needed.
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index f8c6972..b6397c1 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c
...
+static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
- dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
+{
- struct dma_iommu_mapping *mapping = dev->archdata.mapping;
- struct page **pages;
- void *addr = NULL;
- pgprot_t prot;
- if (dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs))
- prot = pgprot_writecombine(pgprot_kernel);
- else
- prot = pgprot_dmacoherent(pgprot_kernel);
- arm_iommu_init(dev);
I found useful to call arm_iommu_init inside arm_iommu_assign_device instead. So, then gen_pool is created only once without the mapping->pool check, instead of relying on the call to ...alloc_attrs, which in my case I never use because I'm implementing iommu_map|unmap_sg functions to see how it goes with the dma mapping.
Regards,
Omar
Hello,
On Thursday, July 14, 2011 8:33 PM Ramirez Luna, Omar wrote:
Add initial proof of concept implementation of DMA-mapping API for devices that have IOMMU support. Right now only dma_alloc_coherent, dma_free_coherent and dma_mmap_coherent functions are supported.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com
...
diff --git a/arch/arm/include/asm/dma-iommu.h b/arch/arm/include/asm/dma-
iommu.h
new file mode 100644 index 0000000..c246ff3 --- /dev/null +++ b/arch/arm/include/asm/dma-iommu.h
...
+int __init arm_iommu_assign_device(struct device *dev, dma_addr_t base,
dma_addr_t size);
__init causes a panic if the iommu is assigned after boot.
In OMAP3 the iommu driver controls isp and dsp address spaces, it is loaded until any of those 2 drivers is needed.
Well, ok. This was just a proof-of-concept/rfc patch, so it was designed only for our particular case.
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index f8c6972..b6397c1 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c
...
+static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
- dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
+{
- struct dma_iommu_mapping *mapping = dev->archdata.mapping;
- struct page **pages;
- void *addr = NULL;
- pgprot_t prot;
- if (dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs))
- prot = pgprot_writecombine(pgprot_kernel);
- else
- prot = pgprot_dmacoherent(pgprot_kernel);
- arm_iommu_init(dev);
I found useful to call arm_iommu_init inside arm_iommu_assign_device instead. So, then gen_pool is created only once without the mapping->pool check, instead of relying on the call to ...alloc_attrs, which in my case I never use because I'm implementing iommu_map|unmap_sg functions to see how it goes with the dma mapping.
Right, this is still on my todo list, but I wanted to focus on cleanup of dma mapping framework and cma first.
Best regards
linaro-mm-sig@lists.linaro.org
-
Marek Szyprowski -
Ramirez Luna, Omar