diff options
| author | Scott Wood <scottwood@freescale.com> | 2014-08-09 01:40:43 +0200 |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2014-09-04 00:58:22 +0200 |
| commit | 6397fc3fb05e73062b9790cfe2760e209ebd7b95 (patch) | |
| tree | 8ea6610042dae6bac8f507fecada7a0bcb22ef48 | |
| parent | powerpc: Dynamic DMA zone limits (diff) | |
| download | linux-6397fc3fb05e73062b9790cfe2760e209ebd7b95.tar.xz linux-6397fc3fb05e73062b9790cfe2760e209ebd7b95.zip | |
powerpc/64: Honor swiotlb limit in coherent allocations
FSL PCI cannot directly address the whole lower 4 GiB due to
conflicts with PCICSRBAR and outbound windows, and thus
max_direct_dma_addr is less than 4GiB. Honor that limit in
dma_direct_alloc_coherent().
Note that setting the DMA mask to 31 bits is not an option, since many
PCI drivers would fail if we reject 32-bit DMA in dma_supported(), and
we have no control over the setting of coherent_dma_mask if
dma_supported() returns true.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Shaohui Xie <Shaohui.Xie@freescale.com>
| -rw-r--r-- | arch/powerpc/kernel/dma.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c index dfd99ef8c63d..a7b0156586dd 100644 --- a/arch/powerpc/kernel/dma.c +++ b/arch/powerpc/kernel/dma.c @@ -15,6 +15,7 @@ #include <asm/vio.h> #include <asm/bug.h> #include <asm/machdep.h> +#include <asm/swiotlb.h> /* * Generic direct DMA implementation @@ -25,6 +26,18 @@ * default the offset is PCI_DRAM_OFFSET. */ +static u64 __maybe_unused get_pfn_limit(struct device *dev) +{ + u64 pfn = (dev->coherent_dma_mask >> PAGE_SHIFT) + 1; + struct dev_archdata __maybe_unused *sd = &dev->archdata; + +#ifdef CONFIG_SWIOTLB + if (sd->max_direct_dma_addr && sd->dma_ops == &swiotlb_dma_ops) + pfn = min_t(u64, pfn, sd->max_direct_dma_addr >> PAGE_SHIFT); +#endif + + return pfn; +} void *dma_direct_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag, @@ -40,7 +53,7 @@ void *dma_direct_alloc_coherent(struct device *dev, size_t size, #else struct page *page; int node = dev_to_node(dev); - u64 pfn = (dev->coherent_dma_mask >> PAGE_SHIFT) + 1; + u64 pfn = get_pfn_limit(dev); int zone; zone = dma_pfn_limit_to_zone(pfn); |