diff options
| author | Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> | 2026-09-24 11:37:51 +0530 |
|---|---|---|
| committer | Marek Szyprowski <m.szyprowski@samsung.com> | 2026-10-09 17:12:07 +0200 |
| commit | af3857eac74e8a957740c083ca7e381e5bf82265 (patch) | |
| tree | 3aefbf30a099b572d4bfe7ce2dfd127be89cd492 /kernel | |
| parent | d5093dbca79110c3180fa7119533cff86affdf0d (diff) | |
| download | linux-next-af3857eac74e8a957740c083ca7e381e5bf82265.tar.gz linux-next-af3857eac74e8a957740c083ca7e381e5bf82265.zip | |
dma: swiotlb: Track whether the pool size was explicitly set
swiotlb_adjust_size() must not override a pool size supplied through the
swiotlb= command-line parameter.
Currently, it determines whether a size was supplied by comparing
default_nslabs with IO_TLB_DEFAULT_SIZE. This fails when the user
explicitly requests the compiled-in default size, allowing the request
to be overwritten by automatic pool sizing.
Record whether swiotlb= supplied a numeric size in swiotlb_cmdline_size_set
and check that flag directly before adjusting the pool size.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Link: https://lore.kernel.org/r/20260924060756.1325156-4-aneesh.kumar@kernel.org
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/dma/swiotlb.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 81f020fe6535..dcce241104ed 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -100,6 +100,7 @@ static struct io_tlb_mem io_tlb_default_mem; static unsigned long default_nslabs = IO_TLB_DEFAULT_SIZE >> IO_TLB_SHIFT; static unsigned long default_nareas; +static bool swiotlb_cmdline_size_set __initdata; /** * struct io_tlb_area - IO TLB memory area descriptor @@ -253,6 +254,7 @@ setup_io_tlb_npages(char *str) /* avoid tail segment of size < IO_TLB_SEGSIZE */ default_nslabs = ALIGN(simple_strtoul(str, &str, 0), IO_TLB_SEGSIZE); + swiotlb_cmdline_size_set = true; } if (*str == ',') ++str; @@ -295,7 +297,7 @@ void __init swiotlb_adjust_size(unsigned long size) * architectures such as those supporting memory encryption to * adjust/expand SWIOTLB size for their use. */ - if (default_nslabs != IO_TLB_DEFAULT_SIZE >> IO_TLB_SHIFT) + if (swiotlb_cmdline_size_set) return; default_nslabs = swiotlb_calc_nslabs(size, default_nareas); |