diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 7e0486ad1318cdf3037b0689340f4faa407ed13b..dba9355e24849ce92bdff29cb0af54fbe46fa771 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -18,7 +18,9 @@ extern const struct dma_map_ops arm_coherent_dma_ops;
static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
{
- return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : NULL;
+ if (IS_ENABLED(CONFIG_MMU) && !IS_ENABLED(CONFIG_ARM_LPAE))
+ return &arm_dma_ops;
+ return NULL;
}
#ifdef __arch_page_to_dma
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 820b60a50125b9ebe2984ba1d09b76e180329381..c54cd7ed90ba5e6a8d64377ef96b19fd4cad9386 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -663,6 +663,11 @@ config ARM_LPAE
depends on MMU && CPU_32v7 && !CPU_32v6 && !CPU_32v5 && \
!CPU_32v4 && !CPU_32v3
select PHYS_ADDR_T_64BIT
+ select SWIOTLB
+ select ARCH_HAS_DMA_COHERENT_TO_PFN
+ select ARCH_HAS_DMA_MMAP_PGPROT
+ select ARCH_HAS_SYNC_DMA_FOR_DEVICE
+ select ARCH_HAS_SYNC_DMA_FOR_CPU
help
Say Y if you have an ARMv7 processor supporting the LPAE page
table format and you would like to access memory beyond the
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 4789c60a86e34552411367282be7309f0d8f779a..6774b03aa405ca4e2dd057fcfe65aa9b9a43a878 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -15,6 +15,7 @@
#include <linux/init.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
+#include <linux/dma-noncoherent.h>
#include <linux/dma-contiguous.h>
#include <linux/highmem.h>
#include <linux/memblock.h>
@@ -1125,6 +1126,19 @@ int arm_dma_supported(struct device *dev, u64 mask)
static const struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
{
+ /*
+ * When CONFIG_ARM_LPAE is set, physical address can extend above
+ * 32-bits, which then can't be addressed by devices that only support
+ * 32-bit DMA.
+ * Use the generic dma-direct / swiotlb ops code in that case, as that
+ * handles bounce buffering for us.
+ *
+ * Note: this checks CONFIG_ARM_LPAE instead of CONFIG_SWIOTLB as the
+ * latter is also selected by the Xen code, but that code for now relies
+ * on non-NULL dev_dma_ops. To be cleaned up later.
+ */
+ if (IS_ENABLED(CONFIG_ARM_LPAE))
+ return NULL;
return coherent ? &arm_coherent_dma_ops : &arm_dma_ops;
}
@@ -2329,6 +2343,9 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
const struct dma_map_ops *dma_ops;
dev->archdata.dma_coherent = coherent;
+#ifdef CONFIG_SWIOTLB
+ dev->dma_coherent = coherent;
+#endif
/*
* Don't override the dma_ops if they have already been set. Ideally
@@ -2363,3 +2380,47 @@ void arch_teardown_dma_ops(struct device *dev)
/* Let arch_setup_dma_ops() start again from scratch upon re-probe */
set_dma_ops(dev, NULL);
}
+
+#ifdef CONFIG_SWIOTLB
+void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
+ size_t size, enum dma_data_direction dir)
+{
+ __dma_page_cpu_to_dev(phys_to_page(paddr), paddr & (PAGE_SIZE - 1),
+ size, dir);
+}
+
+void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
+ size_t size, enum dma_data_direction dir)
+{
+ __dma_page_dev_to_cpu(phys_to_page(paddr), paddr & (PAGE_SIZE - 1),
+ size, dir);
+}
+
+long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,
+ dma_addr_t dma_addr)
+{
+ return dma_to_pfn(dev, dma_addr);
+}
+
+pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,
+ unsigned long attrs)
+{
+ if (!dev_is_dma_coherent(dev))
+ return __get_dma_pgprot(attrs, prot);
+ return prot;
+}
+
+void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
+ gfp_t gfp, unsigned long attrs)
+{
+ return __dma_alloc(dev, size, dma_handle, gfp,
+ __get_dma_pgprot(attrs, PAGE_KERNEL), false,
+ attrs, __builtin_return_address(0));
+}
+
+void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
+ dma_addr_t dma_handle, unsigned long attrs)
+{
+ __arm_dma_free(dev, size, cpu_addr, dma_handle, attrs, false);
+}
+#endif /* CONFIG_SWIOTLB */
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 4920a206dce936fe9ab601bfd569f0133c3d757c..16d373d587c476e3caf81e43f61b5fc325ffa9a4 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -21,6 +21,7 @@
#include <linux/dma-contiguous.h>
#include <linux/sizes.h>
#include <linux/stop_machine.h>
+#include <linux/swiotlb.h>
#include <asm/cp15.h>
#include <asm/mach-types.h>
@@ -463,6 +464,10 @@ static void __init free_highpages(void)
*/
void __init mem_init(void)
{
+#ifdef CONFIG_ARM_LPAE
+ swiotlb_init(1);
+#endif
+
set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
/* this will put all unused low memory onto the freelists */
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 1f628e7ac7097ab40e577904a91f26fce28610b8..b945239621d86255d6a259a9a2911c9a393e0b11 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -116,11 +116,16 @@ int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
int ret;
if (!dev_is_dma_coherent(dev)) {
+ unsigned long pfn;
+
if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
return -ENXIO;
- page = pfn_to_page(arch_dma_coherent_to_pfn(dev, cpu_addr,
- dma_addr));
+ /* If the PFN is not valid, we do not have a struct page */
+ pfn = arch_dma_coherent_to_pfn(dev, cpu_addr, dma_addr);
+ if (!pfn_valid(pfn))
+ return -ENXIO;
+ page = pfn_to_page(pfn);
} else {
page = virt_to_page(cpu_addr);
}
@@ -170,7 +175,11 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
if (!dev_is_dma_coherent(dev)) {
if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
return -ENXIO;
+
+ /* If the PFN is not valid, we do not have a struct page */
pfn = arch_dma_coherent_to_pfn(dev, cpu_addr, dma_addr);
+ if (!pfn_valid(pfn))
+ return -ENXIO;
} else {
pfn = page_to_pfn(virt_to_page(cpu_addr));
}