With this we can do a run time check on the allocation type for either kernel or user using the dma attribute passed to dma-mapping iommu ops.
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 2d11aa0..1f454cc 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -428,6 +428,7 @@ static void __dma_free_remap(void *cpu_addr, size_t size)
arm_vmregion_free(&consistent_head, c);
}
+
#else /* !CONFIG_MMU */
#define __dma_alloc_remap(page, size, gfp, prot, c) page_address(page)
@@ -894,6 +895,35 @@ __iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot)
size_t align;
size_t count = size >> PAGE_SHIFT;
int bit;
+ unsigned long mem_type = (unsigned long)gfp;
+
+
+ if(mem_type){
+
+ struct page_infodma *pages_in;
+
+ pages_in = kzalloc( sizeof(struct page_infodma*), GFP_KERNEL);
+ if(!pages_in)
+ return NULL;
+
+ pages_in->nr_pages = count;
+
+ return (void*)pages_in;
+
+ }
+
+ /*
+ * Align the virtual region allocation - maximum alignment is
+ * a section size, minimum is a page size. This helps reduce
+ * fragmentation of the DMA space, and also prevents allocations
+ * smaller than a section from crossing a section boundary.
+ */
+
+ bit = fls(size - 1);
+ if (bit > SECTION_SHIFT)
+ bit = SECTION_SHIFT;
+ align = 1 << bit;
+
if (!consistent_pte[0]) {
pr_err("%s: not initialised\n", __func__);
@@ -901,16 +931,6 @@ __iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot)
return NULL;
}
- /*
- * Align the virtual region allocation - maximum alignment is
- * a section size, minimum is a page size. This helps reduce
- * fragmentation of the DMA space, and also prevents allocations
- * smaller than a section from crossing a section boundary.
- */
- bit = fls(size - 1);
- if (bit > SECTION_SHIFT)
- bit = SECTION_SHIFT;
- align = 1 << bit;
/*
* Allocate a virtual address in the consistent mapping region.
@@ -946,6 +966,7 @@ __iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot)
return NULL;
}
+
/*
* Create a mapping in device IO address space for specified pages
*/
@@ -973,13 +994,16 @@ __iommu_create_mapping(struct device *dev, struct page **pages, size_t size)
len = (j - i) << PAGE_SHIFT;
ret = iommu_map(mapping->domain, iova, phys, len, 0);
+
if (ret < 0)
goto fail;
+
iova += len;
i = j;
}
return dma_addr;
fail:
+
iommu_unmap(mapping->domain, dma_addr, iova-dma_addr);
__free_iova(mapping, dma_addr, size);
return DMA_ERROR_CODE;
@@ -1007,6 +1031,8 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
struct page **pages;
void *addr = NULL;
+ struct page_infodma *page_ret;
+ unsigned long mem_type;
*handle = DMA_ERROR_CODE;
size = PAGE_ALIGN(size);
@@ -1019,11 +1045,19 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
if (*handle == DMA_ERROR_CODE)
goto err_buffer;
- addr = __iommu_alloc_remap(pages, size, gfp, prot);
+ mem_type = dma_get_attr(DMA_ATTR_USER_SPACE, attrs);
+
+ addr = __iommu_alloc_remap(pages, size, mem_type, prot);
if (!addr)
goto err_mapping;
- return addr;
+ if(mem_type){
+ page_ret = (struct page_infodma *)addr;
+ page_ret->pages = pages;
+ return page_ret;
+ }
+ else
+ return addr;
err_mapping:
__iommu_remove_mapping(dev, *handle, size);
@@ -1071,18 +1105,34 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t handle, struct dma_attrs *attrs)
{
- struct arm_vmregion *c;
+
+ unsigned long mem_type = dma_get_attr(DMA_ATTR_USER_SPACE, attrs);
+
size = PAGE_ALIGN(size);
- c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
- if (c) {
- struct page **pages = c->priv;
- __dma_free_remap(cpu_addr, size);
- __iommu_remove_mapping(dev, handle, size);
- __iommu_free_buffer(dev, pages, size);
+
+ if(mem_type){
+
+ struct page_infodma *pagesin = cpu_addr;
+ if (pagesin) {
+ struct page **pages = pagesin->pages;
+ __iommu_remove_mapping(dev, handle, size);
+ __iommu_free_buffer(dev, pages, size);
+ }
+ }
+ else{
+ struct arm_vmregion *c;
+ c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
+ if (c) {
+ struct page **pages = c->priv;
+ __dma_free_remap(cpu_addr, size);
+ __iommu_remove_mapping(dev, handle, size);
+ __iommu_free_buffer(dev, pages, size);
+ }
}
}
+
/*
* Map a part of the scatter-gather list into contiguous io address space
*/