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dma-mapping: fix 32-bit overflow with CONFIG_ARM_LPAE=n

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On r8a7791/koelsch and shmobile_defconfig, PCIe probing fails with:

    rcar-pcie fe000000.pcie: Adjusted size 0x0 invalid
    rcar-pcie: probe of fe000000.pcie failed with error -22

of_dma_get_range() returns the following map:

    cpu_start 0x40000000 dma_start 0x40000000 size 0x080000000 offset 0
    cpu_start 0x00000000 dma_start 0x00000000 size 0x100000000 offset 0

If CONFIG_ARM_LPAE=n, dma_addr_t is 32-bit.  Hence when assigning
r->dma_start + r->size to dma_end, this value will be truncated to
32-bit, yielding zero when processing the second table entry.
Consequently, both dma_start and dma_end will be zero, leading to a zero
size.

Fix this by changing the dma_start and dma_end variables from dma_addr_t
to u64.

Fixes: e0d072782c734d27 ("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Geert Uytterhoeven 2020-10-26 16:27:55 +01:00 committed by Christoph Hellwig
parent ed8780e3f2
commit 48ab6d5d1f
1 changed files with 3 additions and 3 deletions
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6
drivers/of/device.c
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@ -93,7 +93,7 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
{ {
const struct iommu_ops *iommu; const struct iommu_ops *iommu;
const struct bus_dma_region *map = NULL; const struct bus_dma_region *map = NULL;
dma_addr_t dma_start = 0; u64 dma_start = 0;
u64 mask, end, size = 0; u64 mask, end, size = 0;
bool coherent; bool coherent;
int ret; int ret;
@ -109,10 +109,10 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
return ret == -ENODEV ? 0 : ret; return ret == -ENODEV ? 0 : ret;
} else { } else {
const struct bus_dma_region *r = map; const struct bus_dma_region *r = map;
dma_addr_t dma_end = 0; u64 dma_end = 0;
/* Determine the overall bounds of all DMA regions */ /* Determine the overall bounds of all DMA regions */
for (dma_start = ~(dma_addr_t)0; r->size; r++) { for (dma_start = ~0ULL; r->size; r++) {
/* Take lower and upper limits */ /* Take lower and upper limits */
if (r->dma_start < dma_start) if (r->dma_start < dma_start)
dma_start = r->dma_start; dma_start = r->dma_start;