diff options
| author | Catalin Marinas <catalin.marinas@arm.com> | 2024-08-11 09:09:35 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2024-08-22 06:18:00 +0200 |
| commit | ba0fb44aed47693cc2482427f63ba6cd19051327 (patch) | |
| tree | 621c630705defd780fbeac9b9b103f3c80264c23 /kernel/dma/direct.c | |
| parent | dma-mapping: use bit masking to check VM_DMA_COHERENT (diff) | |
| download | linux-ba0fb44aed47693cc2482427f63ba6cd19051327.tar.xz linux-ba0fb44aed47693cc2482427f63ba6cd19051327.zip | |
dma-mapping: replace zone_dma_bits by zone_dma_limit
The hardware DMA limit might not be power of 2. When RAM range starts
above 0, say 4GB, DMA limit of 30 bits should end at 5GB. A single high
bit can not encode this limit.
Use a plain address for the DMA zone limit instead.
Since the DMA zone can now potentially span beyond 4GB physical limit of
DMA32, make sure to use DMA zone for GFP_DMA32 allocations in that case.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Co-developed-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Petr Tesarik <ptesarik@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'kernel/dma/direct.c')
| -rw-r--r-- | kernel/dma/direct.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 4480a3cd92e0..f2ba074a6a54 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -20,7 +20,7 @@ * it for entirely different regions. In that case the arch code needs to * override the variable below for dma-direct to work properly. */ -unsigned int zone_dma_bits __ro_after_init = 24; +u64 zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); static inline dma_addr_t phys_to_dma_direct(struct device *dev, phys_addr_t phys) @@ -59,7 +59,7 @@ static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 *phys_limit) * zones. */ *phys_limit = dma_to_phys(dev, dma_limit); - if (*phys_limit <= DMA_BIT_MASK(zone_dma_bits)) + if (*phys_limit <= zone_dma_limit) return GFP_DMA; if (*phys_limit <= DMA_BIT_MASK(32)) return GFP_DMA32; @@ -580,7 +580,7 @@ int dma_direct_supported(struct device *dev, u64 mask) * part of the check. */ if (IS_ENABLED(CONFIG_ZONE_DMA)) - min_mask = min_t(u64, min_mask, DMA_BIT_MASK(zone_dma_bits)); + min_mask = min_t(u64, min_mask, zone_dma_limit); return mask >= phys_to_dma_unencrypted(dev, min_mask); } |