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authorGregory CLEMENT <gregory.clement@free-electrons.com>2016-04-15 11:20:13 +0100
committerRussell King <rmk+kernel@armlinux.org.uk>2016-07-14 16:25:31 +0100
commit565068221b90573d0a4ac3e73f1aa960f5571b84 (patch)
tree13b110a9b9e2f0630d4126825374b630c980d6e6
parentf12708965069410691e47d1d216ec7ad1516bfd2 (diff)
ARM: 8561/4: dma-mapping: Fix the coherent case when iommu is used
When doing dma allocation with IOMMU the __iommu_alloc_atomic() was used even when the system was coherent. However, this function allocates from a non-cacheable pool, which is fine when the device is not cache coherent but won't work as expected in the device is cache coherent. Indeed, the CPU and device must access the memory using the same cacheability attributes. Moreover when the devices are coherent, the mmap call must not change the pg_prot flags in the vma struct. The arm_coherent_iommu_mmap_attrs has been updated in the same way that it was done for the arm_dma_mmap in commit 55af8a91640d ("ARM: 8387/1: arm/mm/dma-mapping.c: Add arm_coherent_dma_mmap"). Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/mm/dma-mapping.c86
1 files changed, 65 insertions, 21 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index d2485c7..b7eed75 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1476,13 +1476,16 @@ static struct page **__iommu_get_pages(void *cpu_addr, struct dma_attrs *attrs)
return NULL;
}
-static void *__iommu_alloc_atomic(struct device *dev, size_t size,
- dma_addr_t *handle)
+static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
+ dma_addr_t *handle, int coherent_flag)
{
struct page *page;
void *addr;
- addr = __alloc_from_pool(size, &page);
+ if (coherent_flag == COHERENT)
+ addr = __alloc_simple_buffer(dev, size, gfp, &page);
+ else
+ addr = __alloc_from_pool(size, &page);
if (!addr)
return NULL;
@@ -1498,14 +1501,18 @@ err_mapping:
}
static void __iommu_free_atomic(struct device *dev, void *cpu_addr,
- dma_addr_t handle, size_t size)
+ dma_addr_t handle, size_t size, int coherent_flag)
{
__iommu_remove_mapping(dev, handle, size);
- __free_from_pool(cpu_addr, size);
+ if (coherent_flag == COHERENT)
+ __dma_free_buffer(virt_to_page(cpu_addr), size);
+ else
+ __free_from_pool(cpu_addr, size);
}
-static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
- dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
+static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size,
+ dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs,
+ int coherent_flag)
{
pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL);
struct page **pages;
@@ -1514,8 +1521,9 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
*handle = DMA_ERROR_CODE;
size = PAGE_ALIGN(size);
- if (!gfpflags_allow_blocking(gfp))
- return __iommu_alloc_atomic(dev, size, handle);
+ if (coherent_flag == COHERENT || !gfpflags_allow_blocking(gfp))
+ return __iommu_alloc_simple(dev, size, gfp, handle,
+ coherent_flag);
/*
* Following is a work-around (a.k.a. hack) to prevent pages
@@ -1526,8 +1534,7 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
*/
gfp &= ~(__GFP_COMP);
- /* For now always consider we are in a non-coherent case */
- pages = __iommu_alloc_buffer(dev, size, gfp, attrs, NORMAL);
+ pages = __iommu_alloc_buffer(dev, size, gfp, attrs, coherent_flag);
if (!pages)
return NULL;
@@ -1552,7 +1559,19 @@ err_buffer:
return NULL;
}
-static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
+static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
+ dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
+{
+ return __arm_iommu_alloc_attrs(dev, size, handle, gfp, attrs, NORMAL);
+}
+
+static void *arm_coherent_iommu_alloc_attrs(struct device *dev, size_t size,
+ dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
+{
+ return __arm_iommu_alloc_attrs(dev, size, handle, gfp, attrs, COHERENT);
+}
+
+static int __arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
struct dma_attrs *attrs)
{
@@ -1562,8 +1581,6 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long off = vma->vm_pgoff;
- vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
-
if (!pages)
return -ENXIO;
@@ -1584,19 +1601,34 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
return 0;
}
+static int arm_iommu_mmap_attrs(struct device *dev,
+ struct vm_area_struct *vma, void *cpu_addr,
+ dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs)
+{
+ vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
+
+ return __arm_iommu_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, attrs);
+}
+
+static int arm_coherent_iommu_mmap_attrs(struct device *dev,
+ struct vm_area_struct *vma, void *cpu_addr,
+ dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs)
+{
+ return __arm_iommu_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, attrs);
+}
/*
* free a page as defined by the above mapping.
* Must not be called with IRQs disabled.
*/
-void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
- dma_addr_t handle, struct dma_attrs *attrs)
+void __arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
+ dma_addr_t handle, struct dma_attrs *attrs, int coherent_flag)
{
struct page **pages;
size = PAGE_ALIGN(size);
- if (__in_atomic_pool(cpu_addr, size)) {
- __iommu_free_atomic(dev, cpu_addr, handle, size);
+ if (coherent_flag == COHERENT || __in_atomic_pool(cpu_addr, size)) {
+ __iommu_free_atomic(dev, cpu_addr, handle, size, coherent_flag);
return;
}
@@ -1615,6 +1647,18 @@ void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
__iommu_free_buffer(dev, pages, size, attrs);
}
+void arm_iommu_free_attrs(struct device *dev, size_t size,
+ void *cpu_addr, dma_addr_t handle, struct dma_attrs *attrs)
+{
+ __arm_iommu_free_attrs(dev, size, cpu_addr, handle, attrs, NORMAL);
+}
+
+void arm_coherent_iommu_free_attrs(struct device *dev, size_t size,
+ void *cpu_addr, dma_addr_t handle, struct dma_attrs *attrs)
+{
+ __arm_iommu_free_attrs(dev, size, cpu_addr, handle, attrs, COHERENT);
+}
+
static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr,
size_t size, struct dma_attrs *attrs)
@@ -2019,9 +2063,9 @@ struct dma_map_ops iommu_ops = {
};
struct dma_map_ops iommu_coherent_ops = {
- .alloc = arm_iommu_alloc_attrs,
- .free = arm_iommu_free_attrs,
- .mmap = arm_iommu_mmap_attrs,
+ .alloc = arm_coherent_iommu_alloc_attrs,
+ .free = arm_coherent_iommu_free_attrs,
+ .mmap = arm_coherent_iommu_mmap_attrs,
.get_sgtable = arm_iommu_get_sgtable,
.map_page = arm_coherent_iommu_map_page,