On Wed, 2015-05-20 at 17:09 -0500, Suravee Suthikulpanit wrote:
From http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf, 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
arch/arm64/Kconfig | 1 + arch/arm64/include/asm/dma-mapping.h | 18 ++++++- arch/arm64/mm/dma-mapping.c | 92 ++++++++++++++++++++++++++++++++++++ 3 files changed, 109 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 4269dba..95307b4 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1,5 +1,6 @@ config ARM64 def_bool y
- select ACPI_CCA_REQUIRED if ACPI select ACPI_GENERIC_GSI if ACPI select ACPI_REDUCED_HARDWARE_ONLY if ACPI select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
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>
^^^ This hunk causes build issues with a couple of drivers:
drivers/scsi/megaraid/megaraid_sas_fp.c:69:0: warning: "FALSE" redefined [enabled by default] #define FALSE 0 ^ In file included from include/acpi/acpi.h:58:0, from include/linux/acpi.h:37, from ./arch/arm64/include/asm/dma-mapping.h:21, from include/linux/dma-mapping.h:86, from ./arch/arm64/include/asm/pci.h:7, from include/linux/pci.h:1460, from drivers/scsi/megaraid/megaraid_sas_fp.c:37: include/acpi/actypes.h:433:0: note: this is the location of the previous definition #define FALSE (1 == 0) ^
In file included from include/acpi/acpi.h:58:0, from include/linux/acpi.h:37, from ./arch/arm64/include/asm/dma-mapping.h:21, from include/linux/dma-mapping.h:86, from include/scsi/scsi_cmnd.h:4, from drivers/scsi/ufs/ufshcd.h:60, from drivers/scsi/ufs/ufshcd.c:43: include/acpi/actypes.h:433:41: error: expected identifier before ‘(’ token #define FALSE (1 == 0) ^ drivers/scsi/ufs/unipro.h:203:2: note: in expansion of macro ‘FALSE’ FALSE = 0, ^
This happens because the ACPI definitions of TRUE and FALSE conflict with local definitions in megaraid and enum declaration in ufs.
@@ -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 diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index ef7d112..6e6d6ad 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -415,6 +415,98 @@ 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;