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authorSuthikulpanit, Suravee <Suravee.Suthikulpanit@amd.com>2015-06-10 16:08:53 (GMT)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-06-15 12:40:49 (GMT)
commitb6197b93fa4bcba9313cc415934e3fe27e2db9b0 (patch)
tree8420fa14c410e23aae37f1277e5473ef047ca99d /arch/arm64/include
parentd0562674838c08ff142c0e9a8e12634e133c4361 (diff)
downloadlinux-b6197b93fa4bcba9313cc415934e3fe27e2db9b0.tar.xz
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/include')
-rw-r--r--arch/arm64/include/asm/dma-mapping.h18
1 files changed, 16 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h
index 9437e3d..f0d6d0b 100644
--- a/arch/arm64/include/asm/dma-mapping.h
+++ b/arch/arm64/include/asm/dma-mapping.h
@@ -18,6 +18,7 @@
#ifdef __KERNEL__
+#include <linux/acpi.h>
#include <linux/types.h>
#include <linux/vmalloc.h>
@@ -28,13 +29,23 @@
#define DMA_ERROR_CODE (~(dma_addr_t)0)
extern struct dma_map_ops *dma_ops;
+extern struct dma_map_ops dummy_dma_ops;
static inline struct dma_map_ops *__generic_dma_ops(struct device *dev)
{
- if (unlikely(!dev) || !dev->archdata.dma_ops)
+ if (unlikely(!dev))
return dma_ops;
- else
+ else if (dev->archdata.dma_ops)
return dev->archdata.dma_ops;
+ else if (acpi_disabled)
+ return dma_ops;
+
+ /*
+ * When ACPI is enabled, if arch_set_dma_ops is not called,
+ * we will disable device DMA capability by setting it
+ * to dummy_dma_ops.
+ */
+ return &dummy_dma_ops;
}
static inline struct dma_map_ops *get_dma_ops(struct device *dev)
@@ -48,6 +59,9 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev)
static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
struct iommu_ops *iommu, bool coherent)
{
+ if (!acpi_disabled && !dev->archdata.dma_ops)
+ dev->archdata.dma_ops = dma_ops;
+
dev->archdata.dma_coherent = coherent;
}
#define arch_setup_dma_ops arch_setup_dma_ops