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-rw-r--r--arch/arm/include/asm/dma-mapping.h8
-rw-r--r--arch/arm/mm/dma-mapping.c51
-rw-r--r--arch/arm/mm/init.c12
-rw-r--r--arch/arm/mm/mm.h2
4 files changed, 61 insertions, 12 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 5b579b951503..863cd84eb1a2 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -64,6 +64,7 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
{
return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
}
+
#else
static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
{
@@ -86,6 +87,13 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
}
#endif
+/* The ARM override for dma_max_pfn() */
+static inline unsigned long dma_max_pfn(struct device *dev)
+{
+ return PHYS_PFN_OFFSET + dma_to_pfn(dev, *dev->dma_mask);
+}
+#define dma_max_pfn(dev) dma_max_pfn(dev)
+
/*
* DMA errors are defined by all-bits-set in the DMA address.
*/
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 1272ed202dde..644d91f73b00 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -159,7 +159,7 @@ EXPORT_SYMBOL(arm_coherent_dma_ops);
static u64 get_coherent_dma_mask(struct device *dev)
{
- u64 mask = (u64)arm_dma_limit;
+ u64 mask = (u64)DMA_BIT_MASK(32);
if (dev) {
mask = dev->coherent_dma_mask;
@@ -173,10 +173,30 @@ static u64 get_coherent_dma_mask(struct device *dev)
return 0;
}
- if ((~mask) & (u64)arm_dma_limit) {
- dev_warn(dev, "coherent DMA mask %#llx is smaller "
- "than system GFP_DMA mask %#llx\n",
- mask, (u64)arm_dma_limit);
+ /*
+ * If the mask allows for more memory than we can address,
+ * and we actually have that much memory, then fail the
+ * allocation.
+ */
+ if (sizeof(mask) != sizeof(dma_addr_t) &&
+ mask > (dma_addr_t)~0 &&
+ dma_to_pfn(dev, ~0) > arm_dma_pfn_limit) {
+ dev_warn(dev, "Coherent DMA mask %#llx is larger than dma_addr_t allows\n",
+ mask);
+ dev_warn(dev, "Driver did not use or check the return value from dma_set_coherent_mask()?\n");
+ return 0;
+ }
+
+ /*
+ * Now check that the mask, when translated to a PFN,
+ * fits within the allowable addresses which we can
+ * allocate.
+ */
+ if (dma_to_pfn(dev, mask) < arm_dma_pfn_limit) {
+ dev_warn(dev, "Coherent DMA mask %#llx (pfn %#lx-%#lx) covers a smaller range of system memory than the DMA zone pfn 0x0-%#lx\n",
+ mask,
+ dma_to_pfn(dev, 0), dma_to_pfn(dev, mask) + 1,
+ arm_dma_pfn_limit + 1);
return 0;
}
}
@@ -1007,8 +1027,27 @@ void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
*/
int dma_supported(struct device *dev, u64 mask)
{
- if (mask < (u64)arm_dma_limit)
+ unsigned long limit;
+
+ /*
+ * If the mask allows for more memory than we can address,
+ * and we actually have that much memory, then we must
+ * indicate that DMA to this device is not supported.
+ */
+ if (sizeof(mask) != sizeof(dma_addr_t) &&
+ mask > (dma_addr_t)~0 &&
+ dma_to_pfn(dev, ~0) > arm_dma_pfn_limit)
+ return 0;
+
+ /*
+ * Translate the device's DMA mask to a PFN limit. This
+ * PFN number includes the page which we can DMA to.
+ */
+ limit = dma_to_pfn(dev, mask);
+
+ if (limit < arm_dma_pfn_limit)
return 0;
+
return 1;
}
EXPORT_SYMBOL(dma_supported);
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index ca907f805c57..3e8f106ee5fe 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -209,6 +209,7 @@ EXPORT_SYMBOL(arm_dma_zone_size);
* so a successful GFP_DMA allocation will always satisfy this.
*/
phys_addr_t arm_dma_limit;
+unsigned long arm_dma_pfn_limit;
static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
unsigned long dma_size)
@@ -231,6 +232,7 @@ void __init setup_dma_zone(const struct machine_desc *mdesc)
arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
} else
arm_dma_limit = 0xffffffff;
+ arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
#endif
}
@@ -418,12 +420,10 @@ void __init bootmem_init(void)
* This doesn't seem to be used by the Linux memory manager any
* more, but is used by ll_rw_block. If we can get rid of it, we
* also get rid of some of the stuff above as well.
- *
- * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
- * the system, not the maximum PFN.
*/
- max_low_pfn = max_low - PHYS_PFN_OFFSET;
- max_pfn = max_high - PHYS_PFN_OFFSET;
+ min_low_pfn = min;
+ max_low_pfn = max_low;
+ max_pfn = max_high;
}
/*
@@ -529,7 +529,7 @@ static inline void free_area_high(unsigned long pfn, unsigned long end)
static void __init free_highpages(void)
{
#ifdef CONFIG_HIGHMEM
- unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET;
+ unsigned long max_low = max_low_pfn;
struct memblock_region *mem, *res;
/* set highmem page free */
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index d5a4e9ad8f0f..d5a982d15a88 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -81,8 +81,10 @@ extern __init void add_static_vm_early(struct static_vm *svm);
#ifdef CONFIG_ZONE_DMA
extern phys_addr_t arm_dma_limit;
+extern unsigned long arm_dma_pfn_limit;
#else
#define arm_dma_limit ((phys_addr_t)~0)
+#define arm_dma_pfn_limit (~0ul >> PAGE_SHIFT)
#endif
extern phys_addr_t arm_lowmem_limit;