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authorJia He <justin.he@arm.com>2023-10-28 12:20:59 +0200
committerChristoph Hellwig <hch@lst.de>2023-11-06 08:38:16 +0100
commita409d9600959f3c4b2a48946304c8e01b8d04072 (patch)
tree14667ece1a3a6e50b9451e635403cf2e52821bc9 /kernel/dma/direct.h
parentdma-mapping: move dma_addressing_limited() out of line (diff)
downloadlinux-a409d9600959f3c4b2a48946304c8e01b8d04072.tar.xz
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dma-mapping: fix dma_addressing_limited() if dma_range_map can't cover all system RAM
There is an unusual case that the range map covers right up to the top of system RAM, but leaves a hole somewhere lower down. Then it prevents the nvme device dma mapping in the checking path of phys_to_dma() and causes the hangs at boot. E.g. On an Armv8 Ampere server, the dsdt ACPI table is: Method (_DMA, 0, Serialized) // _DMA: Direct Memory Access { Name (RBUF, ResourceTemplate () { QWordMemory (ResourceConsumer, PosDecode, MinFixed, MaxFixed, Cacheable, ReadWrite, 0x0000000000000000, // Granularity 0x0000000000000000, // Range Minimum 0x00000000FFFFFFFF, // Range Maximum 0x0000000000000000, // Translation Offset 0x0000000100000000, // Length ,, , AddressRangeMemory, TypeStatic) QWordMemory (ResourceConsumer, PosDecode, MinFixed, MaxFixed, Cacheable, ReadWrite, 0x0000000000000000, // Granularity 0x0000006010200000, // Range Minimum 0x000000602FFFFFFF, // Range Maximum 0x0000000000000000, // Translation Offset 0x000000001FE00000, // Length ,, , AddressRangeMemory, TypeStatic) QWordMemory (ResourceConsumer, PosDecode, MinFixed, MaxFixed, Cacheable, ReadWrite, 0x0000000000000000, // Granularity 0x00000060F0000000, // Range Minimum 0x00000060FFFFFFFF, // Range Maximum 0x0000000000000000, // Translation Offset 0x0000000010000000, // Length ,, , AddressRangeMemory, TypeStatic) QWordMemory (ResourceConsumer, PosDecode, MinFixed, MaxFixed, Cacheable, ReadWrite, 0x0000000000000000, // Granularity 0x0000007000000000, // Range Minimum 0x000003FFFFFFFFFF, // Range Maximum 0x0000000000000000, // Translation Offset 0x0000039000000000, // Length ,, , AddressRangeMemory, TypeStatic) }) But the System RAM ranges are: cat /proc/iomem |grep -i ram 90000000-91ffffff : System RAM 92900000-fffbffff : System RAM 880000000-fffffffff : System RAM 8800000000-bff5990fff : System RAM bff59d0000-bff5a4ffff : System RAM bff8000000-bfffffffff : System RAM So some RAM ranges are out of dma_range_map. Fix it by checking whether each of the system RAM resources can be properly encompassed within the dma_range_map. Signed-off-by: Jia He <justin.he@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'kernel/dma/direct.h')
-rw-r--r--kernel/dma/direct.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h
index 97ec892ea0b5..18d346118fe8 100644
--- a/kernel/dma/direct.h
+++ b/kernel/dma/direct.h
@@ -20,6 +20,7 @@ int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr);
int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
enum dma_data_direction dir, unsigned long attrs);
+bool dma_direct_all_ram_mapped(struct device *dev);
size_t dma_direct_max_mapping_size(struct device *dev);
#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \