On Mon, 2018-07-30 at 18:38 +0200, Christoph Hellwig wrote:
> These do the same functionality as the existing helpers, but do it
> simpler, and also allow the (optional) use of CMA.
>
> Note that the swiotlb code now calls into the dma_direct code directly,
> given that it doesn't work with noncoherent caches at all, and isn't called
> when we have an iommu either, so the iommu special case in
> dma_nommu_alloc_coherent isn't required for swiotlb.
I am not convinced that this will produce the same results due to
the way the zone picking works.
As for the interaction with swiotlb, we'll need the FSL guys to have
a look. Scott, do you remember what this is about ?
> Signed-off-by: Christoph Hellwig
> ---
> arch/powerpc/include/asm/pgtable.h | 1 -
> arch/powerpc/kernel/dma-swiotlb.c | 4 +-
> arch/powerpc/kernel/dma.c | 78 --
> arch/powerpc/mm/mem.c | 19
> 4 files changed, 11 insertions(+), 91 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/pgtable.h
> b/arch/powerpc/include/asm/pgtable.h
> index 14c79a7dc855..123de4958d2e 100644
> --- a/arch/powerpc/include/asm/pgtable.h
> +++ b/arch/powerpc/include/asm/pgtable.h
> @@ -38,7 +38,6 @@ extern unsigned long empty_zero_page[];
> extern pgd_t swapper_pg_dir[];
>
> void limit_zone_pfn(enum zone_type zone, unsigned long max_pfn);
> -int dma_pfn_limit_to_zone(u64 pfn_limit);
> extern void paging_init(void);
>
> /*
> diff --git a/arch/powerpc/kernel/dma-swiotlb.c
> b/arch/powerpc/kernel/dma-swiotlb.c
> index f6e0701c5303..25986fcd1e5e 100644
> --- a/arch/powerpc/kernel/dma-swiotlb.c
> +++ b/arch/powerpc/kernel/dma-swiotlb.c
> @@ -46,8 +46,8 @@ static u64 swiotlb_powerpc_get_required(struct device *dev)
> * for everything else.
> */
> const struct dma_map_ops powerpc_swiotlb_dma_ops = {
> - .alloc = __dma_nommu_alloc_coherent,
> - .free = __dma_nommu_free_coherent,
> + .alloc = dma_direct_alloc,
> + .free = dma_direct_free,
> .mmap = dma_nommu_mmap_coherent,
> .map_sg = swiotlb_map_sg_attrs,
> .unmap_sg = swiotlb_unmap_sg_attrs,
> diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
> index 2cfc45acbb52..2b90a403cdac 100644
> --- a/arch/powerpc/kernel/dma.c
> +++ b/arch/powerpc/kernel/dma.c
> @@ -26,75 +26,6 @@
> * can set archdata.dma_data to an unsigned long holding the offset. By
> * 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 = >archdata;
> -
> -#ifdef CONFIG_SWIOTLB
> - if (sd->max_direct_dma_addr && dev->dma_ops == _swiotlb_dma_ops)
> - pfn = min_t(u64, pfn, sd->max_direct_dma_addr >> PAGE_SHIFT);
> -#endif
> -
> - return pfn;
> -}
> -
> -#ifndef CONFIG_NOT_COHERENT_CACHE
> -void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
> - dma_addr_t *dma_handle, gfp_t flag,
> - unsigned long attrs)
> -{
> - void *ret;
> - struct page *page;
> - int node = dev_to_node(dev);
> -#ifdef CONFIG_FSL_SOC
> - u64 pfn = get_pfn_limit(dev);
> - int zone;
> -
> - /*
> - * This code should be OK on other platforms, but we have drivers that
> - * don't set coherent_dma_mask. As a workaround we just ifdef it. This
> - * whole routine needs some serious cleanup.
> - */
> -
> - zone = dma_pfn_limit_to_zone(pfn);
> - if (zone < 0) {
> - dev_err(dev, "%s: No suitable zone for pfn %#llx\n",
> - __func__, pfn);
> - return NULL;
> - }
> -
> - switch (zone) {
> - case ZONE_DMA:
> - flag |= GFP_DMA;
> - break;
> -#ifdef CONFIG_ZONE_DMA32
> - case ZONE_DMA32:
> - flag |= GFP_DMA32;
> - break;
> -#endif
> - };
> -#endif /* CONFIG_FSL_SOC */
> -
> - page = alloc_pages_node(node, flag, get_order(size));
> - if (page == NULL)
> - return NULL;
> - ret = page_address(page);
> - memset(ret, 0, size);
> - *dma_handle = phys_to_dma(dev,__pa(ret));
> -
> - return ret;
> -}
> -
> -void __dma_nommu_free_coherent(struct device *dev, size_t size,
> - void *vaddr, dma_addr_t dma_handle,
> - unsigned long attrs)
> -{
> - free_pages((unsigned long)vaddr, get_order(size));
> -}
> -#endif /* !CONFIG_NOT_COHERENT_CACHE */
> -
> static void *dma_nommu_alloc_coherent(struct device *dev, size_t size,
> dma_addr_t *dma_handle, gfp_t flag,
> unsigned long attrs)
> @@ -105,8 +36,12 @@ static void *dma_nommu_alloc_coherent(struct device *dev,
> size_t size,
>* we can really use the direct ops
>*/
> if (dma_direct_supported(dev, dev->coherent_dma_mask))
>
