Re: [PATCH] xtensa: use generic dma_noncoherent_ops

[Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>]

ping?  Any comments?

On Tue, Jun 19, 2018 at 09:03:16AM +0200, Christoph Hellwig wrote:
> Switch to the generic noncoherent direct mapping implementation.
> 
> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
> ---
>  arch/xtensa/Kconfig                   |   3 +
>  arch/xtensa/include/asm/Kbuild        |   1 +
>  arch/xtensa/include/asm/dma-mapping.h |  26 ------
>  arch/xtensa/kernel/pci-dma.c          | 130 +++-----------------------
>  4 files changed, 19 insertions(+), 141 deletions(-)
>  delete mode 100644 arch/xtensa/include/asm/dma-mapping.h
> 
> diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
> index d575e8701955..373708c77367 100644
> --- a/arch/xtensa/Kconfig
> +++ b/arch/xtensa/Kconfig
> @@ -5,11 +5,14 @@ config ZONE_DMA
>  config XTENSA
>  	def_bool y
>  	select ARCH_NO_COHERENT_DMA_MMAP if !MMU
> +	select ARCH_HAS_SYNC_DMA_FOR_CPU
> +	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
>  	select ARCH_WANT_FRAME_POINTERS
>  	select ARCH_WANT_IPC_PARSE_VERSION
>  	select BUILDTIME_EXTABLE_SORT
>  	select CLONE_BACKWARDS
>  	select COMMON_CLK
> +	select DMA_NONCOHERENT_OPS
>  	select GENERIC_ATOMIC64
>  	select GENERIC_CLOCKEVENTS
>  	select GENERIC_IRQ_SHOW
> diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild
> index e5e1e61c538c..82c756431b49 100644
> --- a/arch/xtensa/include/asm/Kbuild
> +++ b/arch/xtensa/include/asm/Kbuild
> @@ -3,6 +3,7 @@ generic-y += compat.h
>  generic-y += device.h
>  generic-y += div64.h
>  generic-y += dma-contiguous.h
> +generic-y += dma-mapping.h
>  generic-y += emergency-restart.h
>  generic-y += exec.h
>  generic-y += extable.h
> diff --git a/arch/xtensa/include/asm/dma-mapping.h b/arch/xtensa/include/asm/dma-mapping.h
> deleted file mode 100644
> index 44098800dad7..000000000000
> --- a/arch/xtensa/include/asm/dma-mapping.h
> +++ /dev/null
> @@ -1,26 +0,0 @@
> -/*
> - * This file is subject to the terms and conditions of the GNU General Public
> - * License.  See the file "COPYING" in the main directory of this archive
> - * for more details.
> - *
> - * Copyright (C) 2003 - 2005 Tensilica Inc.
> - * Copyright (C) 2015 Cadence Design Systems Inc.
> - */
> -
> -#ifndef _XTENSA_DMA_MAPPING_H
> -#define _XTENSA_DMA_MAPPING_H
> -
> -#include <asm/cache.h>
> -#include <asm/io.h>
> -
> -#include <linux/mm.h>
> -#include <linux/scatterlist.h>
> -
> -extern const struct dma_map_ops xtensa_dma_map_ops;
> -
> -static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
> -{
> -	return &xtensa_dma_map_ops;
> -}
> -
> -#endif	/* _XTENSA_DMA_MAPPING_H */
> diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
> index 392b4a80ebc2..a83d60e92908 100644
> --- a/arch/xtensa/kernel/pci-dma.c
> +++ b/arch/xtensa/kernel/pci-dma.c
> @@ -16,26 +16,24 @@
>   */
>  
>  #include <linux/dma-contiguous.h>
> +#include <linux/dma-noncoherent.h>
>  #include <linux/dma-direct.h>
>  #include <linux/gfp.h>
>  #include <linux/highmem.h>
>  #include <linux/mm.h>
> -#include <linux/module.h>
> -#include <linux/pci.h>
> -#include <linux/string.h>
>  #include <linux/types.h>
>  #include <asm/cacheflush.h>
>  #include <asm/io.h>
>  
> -static void do_cache_op(dma_addr_t dma_handle, size_t size,
> +static void do_cache_op(phys_addr_t paddr, size_t size,
>  			void (*fn)(unsigned long, unsigned long))
>  {
> -	unsigned long off = dma_handle & (PAGE_SIZE - 1);
> -	unsigned long pfn = PFN_DOWN(dma_handle);
> +	unsigned long off = paddr & (PAGE_SIZE - 1);
> +	unsigned long pfn = PFN_DOWN(paddr);
>  	struct page *page = pfn_to_page(pfn);
>  
>  	if (!PageHighMem(page))
> -		fn((unsigned long)bus_to_virt(dma_handle), size);
> +		fn((unsigned long)phys_to_virt(paddr), size);
>  	else
>  		while (size > 0) {
>  			size_t sz = min_t(size_t, size, PAGE_SIZE - off);
> @@ -49,14 +47,13 @@ static void do_cache_op(dma_addr_t dma_handle, size_t size,
>  		}
>  }
>  
> -static void xtensa_sync_single_for_cpu(struct device *dev,
> -				       dma_addr_t dma_handle, size_t size,
> -				       enum dma_data_direction dir)
> +void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
> +		size_t size, enum dma_data_direction dir)
>  {
>  	switch (dir) {
>  	case DMA_BIDIRECTIONAL:
>  	case DMA_FROM_DEVICE:
> -		do_cache_op(dma_handle, size, __invalidate_dcache_range);
> +		do_cache_op(paddr, size, __invalidate_dcache_range);
>  		break;
>  
>  	case DMA_NONE:
> @@ -68,15 +65,14 @@ static void xtensa_sync_single_for_cpu(struct device *dev,
>  	}
>  }
>  
> -static void xtensa_sync_single_for_device(struct device *dev,
> -					  dma_addr_t dma_handle, size_t size,
> -					  enum dma_data_direction dir)
> +void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
> +		size_t size, enum dma_data_direction dir)
>  {
>  	switch (dir) {
>  	case DMA_BIDIRECTIONAL:
>  	case DMA_TO_DEVICE:
>  		if (XCHAL_DCACHE_IS_WRITEBACK)
> -			do_cache_op(dma_handle, size, __flush_dcache_range);
> +			do_cache_op(paddr, size, __flush_dcache_range);
>  		break;
>  
>  	case DMA_NONE:
> @@ -88,40 +84,13 @@ static void xtensa_sync_single_for_device(struct device *dev,
>  	}
>  }
>  
> -static void xtensa_sync_sg_for_cpu(struct device *dev,
> -				   struct scatterlist *sg, int nents,
> -				   enum dma_data_direction dir)
> -{
> -	struct scatterlist *s;
> -	int i;
> -
> -	for_each_sg(sg, s, nents, i) {
> -		xtensa_sync_single_for_cpu(dev, sg_dma_address(s),
> -					   sg_dma_len(s), dir);
> -	}
> -}
> -
> -static void xtensa_sync_sg_for_device(struct device *dev,
> -				      struct scatterlist *sg, int nents,
> -				      enum dma_data_direction dir)
> -{
> -	struct scatterlist *s;
> -	int i;
> -
> -	for_each_sg(sg, s, nents, i) {
> -		xtensa_sync_single_for_device(dev, sg_dma_address(s),
> -					      sg_dma_len(s), dir);
> -	}
> -}
> -
>  /*
>   * Note: We assume that the full memory space is always mapped to 'kseg'
>   *	 Otherwise we have to use page attributes (not implemented).
>   */
>  
> -static void *xtensa_dma_alloc(struct device *dev, size_t size,
> -			      dma_addr_t *handle, gfp_t flag,
> -			      unsigned long attrs)
> +void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
> +		gfp_t flag, unsigned long attrs)
>  {
>  	unsigned long ret;
>  	unsigned long uncached;
> @@ -171,8 +140,8 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size,
>  	return (void *)uncached;
>  }
>  
> -static void xtensa_dma_free(struct device *dev, size_t size, void *vaddr,
> -			    dma_addr_t dma_handle, unsigned long attrs)
> +void arch_dma_free(struct device *dev, size_t size, void *vaddr,
> +		dma_addr_t dma_handle, unsigned long attrs)
>  {
>  	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
>  	unsigned long addr = (unsigned long)vaddr;
> @@ -192,72 +161,3 @@ static void xtensa_dma_free(struct device *dev, size_t size, void *vaddr,
>  	if (!dma_release_from_contiguous(dev, page, count))
>  		__free_pages(page, get_order(size));
>  }
> -
> -static dma_addr_t xtensa_map_page(struct device *dev, struct page *page,
> -				  unsigned long offset, size_t size,
> -				  enum dma_data_direction dir,
> -				  unsigned long attrs)
> -{
> -	dma_addr_t dma_handle = page_to_phys(page) + offset;
> -
> -	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
> -		xtensa_sync_single_for_device(dev, dma_handle, size, dir);
> -
> -	return dma_handle;
> -}
> -
> -static void xtensa_unmap_page(struct device *dev, dma_addr_t dma_handle,
> -			      size_t size, enum dma_data_direction dir,
> -			      unsigned long attrs)
> -{
> -	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
> -		xtensa_sync_single_for_cpu(dev, dma_handle, size, dir);
> -}
> -
> -static int xtensa_map_sg(struct device *dev, struct scatterlist *sg,
> -			 int nents, enum dma_data_direction dir,
> -			 unsigned long attrs)
> -{
> -	struct scatterlist *s;
> -	int i;
> -
> -	for_each_sg(sg, s, nents, i) {
> -		s->dma_address = xtensa_map_page(dev, sg_page(s), s->offset,
> -						 s->length, dir, attrs);
> -	}
> -	return nents;
> -}
> -
> -static void xtensa_unmap_sg(struct device *dev,
> -			    struct scatterlist *sg, int nents,
> -			    enum dma_data_direction dir,
> -			    unsigned long attrs)
> -{
> -	struct scatterlist *s;
> -	int i;
> -
> -	for_each_sg(sg, s, nents, i) {
> -		xtensa_unmap_page(dev, sg_dma_address(s),
> -				  sg_dma_len(s), dir, attrs);
> -	}
> -}
> -
> -int xtensa_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
> -{
> -	return 0;
> -}
> -
> -const struct dma_map_ops xtensa_dma_map_ops = {
> -	.alloc = xtensa_dma_alloc,
> -	.free = xtensa_dma_free,
> -	.map_page = xtensa_map_page,
> -	.unmap_page = xtensa_unmap_page,
> -	.map_sg = xtensa_map_sg,
> -	.unmap_sg = xtensa_unmap_sg,
> -	.sync_single_for_cpu = xtensa_sync_single_for_cpu,
> -	.sync_single_for_device = xtensa_sync_single_for_device,
> -	.sync_sg_for_cpu = xtensa_sync_sg_for_cpu,
> -	.sync_sg_for_device = xtensa_sync_sg_for_device,
> -	.mapping_error = xtensa_dma_mapping_error,
> -};
> -EXPORT_SYMBOL(xtensa_dma_map_ops);
> -- 
> 2.17.1
> 
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