Merge "ARM: another fix for the DMA mapping checks" (df4aa3b0) · Commits · e / devices / android_kernel_sony_msm8994

arch/arm/mm/dma-mapping.c

+41 −8

Original line number	Diff line number	Diff line
		@@ -9,6 +9,7 @@
		*
		* DMA uncached mapping support.
		*/
		#include <linux/bootmem.h>
		#include <linux/module.h>
		#include <linux/mm.h>
		#include <linux/gfp.h>
		@@ -157,6 +158,44 @@ struct dma_map_ops arm_coherent_dma_ops = {
		};
		EXPORT_SYMBOL(arm_coherent_dma_ops);

		static int __dma_supported(struct device *dev, u64 mask, bool warn)
		{
		unsigned long max_dma_pfn;

		/*
		* 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) < max_pfn) {
		if (warn) {
		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;
		}

		max_dma_pfn = min(max_pfn, arm_dma_pfn_limit);

		/*
		* Translate the device's DMA mask to a PFN limit. This
		* PFN number includes the page which we can DMA to.
		*/
		if (dma_to_pfn(dev, mask) < max_dma_pfn) {
		if (warn)
		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,
		max_dma_pfn + 1);
		return 0;
		}

		return 1;
		}

		static u64 get_coherent_dma_mask(struct device *dev)
		{
		u64 mask = (u64)arm_dma_limit;
		@@ -173,13 +212,9 @@ 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 (!__dma_supported(dev, mask, true))
		return 0;
		}
		}

		return mask;
		}
		@@ -1037,9 +1072,7 @@ 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)
		return 0;
		return 1;
		return __dma_supported(dev, mask, false);
		}
		EXPORT_SYMBOL(dma_supported);

arch/arm/mm/mm.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -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;