Hello,
On Wednesday, January 25, 2012 1:47 PM Hiroshi Doyu wrote:
Hi Marek,
On Fri, 9 Dec 2011 17:39:58 +0100 Marek Szyprowski m.szyprowski@samsung.com wrote:
This patch add a complete implementation of DMA-mapping API for devices that have IOMMU support. All DMA-mapping calls are supported.
This patch contains some of the code kindly provided by Krishna Reddy vdumpa@nvidia.com and Andrzej Pietrasiewicz andrzej.p@samsung.com
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com
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
arch/arm/Kconfig | 8 + arch/arm/include/asm/device.h | 3 + arch/arm/include/asm/dma-iommu.h | 36 +++ arch/arm/mm/dma-mapping.c | 637 +++++++++++++++++++++++++++++++++++++- arch/arm/mm/vmregion.h | 2 +- 5 files changed, 671 insertions(+), 15 deletions(-) create mode 100644 arch/arm/include/asm/dma-iommu.h
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 8827c9b..87416fc 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -42,6 +42,14 @@ config ARM config ARM_HAS_SG_CHAIN bool
+config NEED_SG_DMA_LENGTH
bool+config ARM_DMA_USE_IOMMU
select NEED_SG_DMA_LENGTHselect ARM_HAS_SG_CHAINboolconfig HAVE_PWM bool
diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h index 6e2cb0e..b69c0d3 100644 --- a/arch/arm/include/asm/device.h +++ b/arch/arm/include/asm/device.h @@ -14,6 +14,9 @@ struct dev_archdata { #ifdef CONFIG_IOMMU_API void *iommu; /* private IOMMU data */ #endif +#ifdef CONFIG_ARM_DMA_USE_IOMMU
struct dma_iommu_mapping *mapping;+#endif };
struct omap_device; diff --git a/arch/arm/include/asm/dma-iommu.h b/arch/arm/include/asm/dma-iommu.h new file mode 100644 index 0000000..6668b41 --- /dev/null +++ b/arch/arm/include/asm/dma-iommu.h @@ -0,0 +1,36 @@ +#ifndef ASMARM_DMA_IOMMU_H +#define ASMARM_DMA_IOMMU_H
+#ifdef __KERNEL__
+#include <linux/mm_types.h> +#include <linux/scatterlist.h> +#include <linux/dma-debug.h> +#include <linux/kmemcheck.h>
+#include <asm/memory.h>
+struct dma_iommu_mapping {
/* iommu specific data */struct iommu_domain *domain;void *bitmap;size_t bits;unsigned int order;dma_addr_t base;spinlock_t lock;struct kref kref;+};
+struct dma_iommu_mapping * +arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size,
int order);+void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping);
+int arm_iommu_attach_device(struct device *dev,
struct dma_iommu_mapping *mapping);+#endif /* __KERNEL__ */ +#endif diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 4845c09..7ac5a95 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -27,6 +27,9 @@ #include <asm/sizes.h> #include <asm/mach/arch.h>
+#include <linux/iommu.h> +#include <asm/dma-iommu.h>
#include "mm.h"
/*
.....
+static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle,
size_t size, enum dma_data_direction dir,struct dma_attrs *attrs)+{
struct dma_iommu_mapping *mapping = dev->archdata.mapping;dma_addr_t iova = handle & PAGE_MASK;struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));int offset = handle & ~PAGE_MASK;if (!iova)return;if (!arch_is_coherent())__dma_page_dev_to_cpu(page, offset, size, dir);iommu_unmap(mapping->domain, iova, size);Is __free_iova() needed here as below?
Modified arch/arm/mm/dma-mapping.c diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 9aa1675..66830b2 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1212,6 +1212,7 @@ static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle, __dma_page_dev_to_cpu(page, offset, size, dir);
iommu_unmap(mapping->domain, iova, size);
__free_iova(mapping, iova, size);}
Right, thanks for finding this bug!
Best regards