Messages in this thread Patch in this message | | | From | Guo Ren <> | Date | Thu, 16 Sep 2021 09:20:32 +0800 | Subject | Re: [RFC PATCH V4 3/6] RISC-V: Support a new config option for non-coherent DMA |
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On Wed, Sep 15, 2021 at 3:48 PM Christoph Hellwig <hch@lst.de> wrote: > > On Sat, Sep 11, 2021 at 05:21:36PM +0800, guoren@kernel.org wrote: > > + select DMA_GLOBAL_POOL > > + select DMA_DIRECT_REMAP > > No need to select DMA_GLOBAL_POOL when DMA_DIRECT_REMAP is select. If we want to support PBMT & global_dma_pool both in riscv. Could they work together in arch/riscv with [1]?
[1]: https://lore.kernel.org/lkml/20210818142715.GA10755@lst.de/T/
> > Also a patch just to add a option that is not selected and won't build > if selected does not make sense. I just want to rebase on Atish's patch and append DMA_DIRECT_REMAP. Okay, DMA_DIRECT_REMAP & DMA_GLOBAL_POOL should be separated from the patch.
--- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -156,9 +156,14 @@ void *dma_direct_alloc(struct device *dev, size_t size,
if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && + !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && !dev_is_dma_coherent(dev)) return arch_dma_alloc(dev, size, dma_handle, gfp, attrs);
+ if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && + !dev_is_dma_coherent(dev)) + return dma_alloc_from_global_coherent(dev, size, dma_handle); + /* * Remapping or decrypting memory may block. If either is required and * we can't block, allocate the memory from the atomic pools. @@ -255,11 +260,19 @@ void dma_direct_free(struct device *dev, size_t size,
if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && + !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && !dev_is_dma_coherent(dev)) { arch_dma_free(dev, size, cpu_addr, dma_addr, attrs); return; }
+ if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && + !dev_is_dma_coherent(dev)) { + if (!dma_release_from_global_coherent(page_order, cpu_addr)) + WARN_ON_ONCE(1); + return; + } + Here CONFIG_DMA_GLOBAL_POOL is independent from CONFIG_DMA_DIRECT_REMAP.
/* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */ if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && dma_free_from_pool(dev, cpu_addr, PAGE_ALIGN(size))) -- Best Regards Guo Ren
ML: https://lore.kernel.org/linux-csky/
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