Messages in this thread | | | From | Atish Patra <> | Date | Wed, 15 Sep 2021 21:39:19 -0700 | 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 6:21 PM Guo Ren <guoren@kernel.org> wrote: > > 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]?
We don't have to worry about it as the next version of my series will use the simpler dma_uncached functionality to support uncached window approach taken by starlight socs.
I was supposed to send it sooner but got busy with PMU stuff and a bad flu :(.
> > [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/ > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv
-- Regards, Atish
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