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authorSuthikulpanit, Suravee <Suravee.Suthikulpanit@amd.com>2015-06-10 18:08:53 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-06-15 14:40:49 +0200
commitb6197b93fa4bcba9313cc415934e3fe27e2db9b0 (patch)
tree8420fa14c410e23aae37f1277e5473ef047ca99d /arch/arm64/mm
parentACPI / scan: Parse _CCA and setup device coherency (diff)
downloadlinux-b6197b93fa4bcba9313cc415934e3fe27e2db9b0.tar.xz
linux-b6197b93fa4bcba9313cc415934e3fe27e2db9b0.zip
arm64 : Introduce support for ACPI _CCA object
section 6.2.17 _CCA states that ARM platforms require ACPI _CCA object to be specified for DMA-cabpable devices. Therefore, this patch specifies ACPI_CCA_REQUIRED in arm64 Kconfig. In addition, to handle the case when _CCA is missing, arm64 would assign dummy_dma_ops to disable DMA capability of the device. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'arch/arm64/mm')
-rw-r--r--arch/arm64/mm/dma-mapping.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index b0bd4e5fd5cf..d16a1cead23f 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -414,6 +414,98 @@ out:
return -ENOMEM;
}
+/********************************************
+ * The following APIs are for dummy DMA ops *
+ ********************************************/
+
+static void *__dummy_alloc(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flags,
+ struct dma_attrs *attrs)
+{
+ return NULL;
+}
+
+static void __dummy_free(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle,
+ struct dma_attrs *attrs)
+{
+}
+
+static int __dummy_mmap(struct device *dev,
+ struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ struct dma_attrs *attrs)
+{
+ return -ENXIO;
+}
+
+static dma_addr_t __dummy_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ return DMA_ERROR_CODE;
+}
+
+static void __dummy_unmap_page(struct device *dev, dma_addr_t dev_addr,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+}
+
+static int __dummy_map_sg(struct device *dev, struct scatterlist *sgl,
+ int nelems, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ return 0;
+}
+
+static void __dummy_unmap_sg(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+}
+
+static void __dummy_sync_single(struct device *dev,
+ dma_addr_t dev_addr, size_t size,
+ enum dma_data_direction dir)
+{
+}
+
+static void __dummy_sync_sg(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir)
+{
+}
+
+static int __dummy_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
+{
+ return 1;
+}
+
+static int __dummy_dma_supported(struct device *hwdev, u64 mask)
+{
+ return 0;
+}
+
+struct dma_map_ops dummy_dma_ops = {
+ .alloc = __dummy_alloc,
+ .free = __dummy_free,
+ .mmap = __dummy_mmap,
+ .map_page = __dummy_map_page,
+ .unmap_page = __dummy_unmap_page,
+ .map_sg = __dummy_map_sg,
+ .unmap_sg = __dummy_unmap_sg,
+ .sync_single_for_cpu = __dummy_sync_single,
+ .sync_single_for_device = __dummy_sync_single,
+ .sync_sg_for_cpu = __dummy_sync_sg,
+ .sync_sg_for_device = __dummy_sync_sg,
+ .mapping_error = __dummy_mapping_error,
+ .dma_supported = __dummy_dma_supported,
+};
+EXPORT_SYMBOL(dummy_dma_ops);
+
static int __init arm64_dma_init(void)
{
int ret;