[PATCH 5.19 0949/1157] swiotlb: fail map correctly with failed io_tlb_default_mem

Greg Kroah-Hartman
2022-08-16T00:47:04Z

From: Robin Murphy <robin.murphy@arm.com>

[ Upstream commit c51ba246cb172c9e947dc6fb8868a1eaf0b2a913 ]

In the failure case of trying to use a buffer which we'd previously
failed to allocate, the "!mem" condition is no longer sufficient since
io_tlb_default_mem became static and assigned by default. Update the
condition to work as intended per the rest of that conversion.

Fixes: 463e862ac63e ("swiotlb: Convert io_default_tlb_mem to static allocation")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/dma/swiotlb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index cb50f8d38360..5830dce6081b 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -580,7 +580,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
int index;
phys_addr_t tlb_addr;

- if (!mem)
+ if (!mem || !mem->nslabs)
panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");

if (cc_platform_has(CC_ATTR_MEM_ENCRYPT))
--
2.35.1