diff mbox series

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

Message ID 20201026152755.3738293-1-geert+renesas@glider.be
State Under Review
Delegated to: Geert Uytterhoeven
Headers show
Series dma-mapping: Fix 32-bit overflow with CONFIG_ARM_LPAE=n | expand

Commit Message

Geert Uytterhoeven Oct. 26, 2020, 3:27 p.m. UTC
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>
---
 drivers/of/device.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Christoph Hellwig Oct. 27, 2020, 7:55 a.m. UTC | #1
Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Rob and Frank: do you want to take this through the OF tree, or should
I queue it up in the dma-mapping tree that caused the problem?
Christoph Hellwig Oct. 29, 2020, 3:59 p.m. UTC | #2
On Tue, Oct 27, 2020 at 08:55:51AM +0100, Christoph Hellwig wrote:
> Looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> 
> Rob and Frank: do you want to take this through the OF tree, or should
> I queue it up in the dma-mapping tree that caused the problem?

I've picked this up in the dma-mapping tree so that we don't miss
rc2.
Rob Herring Oct. 30, 2020, 6:44 p.m. UTC | #3
On Thu, Oct 29, 2020 at 04:59:18PM +0100, Christoph Hellwig wrote:
> On Tue, Oct 27, 2020 at 08:55:51AM +0100, Christoph Hellwig wrote:
> > Looks good:
> > 
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
> > 
> > Rob and Frank: do you want to take this through the OF tree, or should
> > I queue it up in the dma-mapping tree that caused the problem?
> 
> I've picked this up in the dma-mapping tree so that we don't miss
> rc2.

Thanks.

Rob
diff mbox series

Patch

diff --git a/drivers/of/device.c b/drivers/of/device.c
index 655dee422563f05f..3a469c79e6b05de4 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -93,7 +93,7 @@  int of_dma_configure_id(struct device *dev, struct device_node *np,
 {
 	const struct iommu_ops *iommu;
 	const struct bus_dma_region *map = NULL;
-	dma_addr_t dma_start = 0;
+	u64 dma_start = 0;
 	u64 mask, end, size = 0;
 	bool coherent;
 	int ret;
@@ -109,10 +109,10 @@  int of_dma_configure_id(struct device *dev, struct device_node *np,
 			return ret == -ENODEV ? 0 : ret;
 	} else {
 		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 */
-		for (dma_start = ~(dma_addr_t)0; r->size; r++) {
+		for (dma_start = ~0ULL; r->size; r++) {
 			/* Take lower and upper limits */
 			if (r->dma_start < dma_start)
 				dma_start = r->dma_start;