swiotlb: clear io_tlb_start and io_tlb_end in swiotlb_exit
Otherwise is_swiotlb_buffer will return false positives when
we first initialize a swiotlb buffer, but then free it because
we have an IOMMU available.
Fixes: 55897af63091 ("dma-direct: merge swiotlb_dma_ops into the dma_direct code")
Reported-by: Sibren Vasse <sibren@sibrenvasse.nl>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Sibren Vasse <sibren@sibrenvasse.nl>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index d636177..1fb6fd6 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -378,6 +378,8 @@ void __init swiotlb_exit(void)
memblock_free_late(io_tlb_start,
PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
}
+ io_tlb_start = 0;
+ io_tlb_end = 0;
io_tlb_nslabs = 0;
max_segment = 0;
}