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| author | Baochen Qiang <quic_bqiang@quicinc.com> | 2025-03-07 11:03:50 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-03-28 22:03:26 +0100 |
| commit | ca3c033a4fe1e55cdadb2f9c642ba253ea283ecc (patch) | |
| tree | f01f8846a4a50d5191c112b317158bb69b73fd1e /kernel/dma | |
| parent | db7dd032eeb2a3766f471c674dd0dc95a124e608 (diff) | |
| download | linux-ca3c033a4fe1e55cdadb2f9c642ba253ea283ecc.tar.gz linux-ca3c033a4fe1e55cdadb2f9c642ba253ea283ecc.tar.bz2 linux-ca3c033a4fe1e55cdadb2f9c642ba253ea283ecc.zip | |
dma-mapping: fix missing clear bdr in check_ram_in_range_map()
[ Upstream commit 8324993f60305e50f27b98358b01b9837e10d159 ]
As discussed in [1], if 'bdr' is set once, it would never get
cleared, hence 0 is always returned.
Refactor the range check hunk into a new helper dma_find_range(),
which allows 'bdr' to be cleared in each iteration.
Link: https://lore.kernel.org/all/64931fac-085b-4ff3-9314-84bac2fa9bdb@quicinc.com/ # [1]
Fixes: a409d9600959 ("dma-mapping: fix dma_addressing_limited() if dma_range_map can't cover all system RAM")
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Link: https://lore.kernel.org/r/20250307030350.69144-1-quic_bqiang@quicinc.com
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/dma')
| -rw-r--r-- | kernel/dma/direct.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 5b4e6d3bf7bc..b8fe0b3d0ffb 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -584,6 +584,22 @@ int dma_direct_supported(struct device *dev, u64 mask) return mask >= phys_to_dma_unencrypted(dev, min_mask); } +static const struct bus_dma_region *dma_find_range(struct device *dev, + unsigned long start_pfn) +{ + const struct bus_dma_region *m; + + for (m = dev->dma_range_map; PFN_DOWN(m->size); m++) { + unsigned long cpu_start_pfn = PFN_DOWN(m->cpu_start); + + if (start_pfn >= cpu_start_pfn && + start_pfn - cpu_start_pfn < PFN_DOWN(m->size)) + return m; + } + + return NULL; +} + /* * To check whether all ram resource ranges are covered by dma range map * Returns 0 when further check is needed @@ -593,20 +609,12 @@ static int check_ram_in_range_map(unsigned long start_pfn, unsigned long nr_pages, void *data) { unsigned long end_pfn = start_pfn + nr_pages; - const struct bus_dma_region *bdr = NULL; - const struct bus_dma_region *m; struct device *dev = data; while (start_pfn < end_pfn) { - for (m = dev->dma_range_map; PFN_DOWN(m->size); m++) { - unsigned long cpu_start_pfn = PFN_DOWN(m->cpu_start); + const struct bus_dma_region *bdr; - if (start_pfn >= cpu_start_pfn && - start_pfn - cpu_start_pfn < PFN_DOWN(m->size)) { - bdr = m; - break; - } - } + bdr = dma_find_range(dev, start_pfn); if (!bdr) return 1; |