[PATCH 7/8] powerpc/dma: split the two __dma_alloc_coherent implementations

Christophe Leroy christophe.leroy at c-s.fr
Mon Dec 17 17:51:05 AEDT 2018



Le 16/12/2018 à 18:19, Christoph Hellwig a écrit :
> The implemementation for the CONFIG_NOT_COHERENT_CACHE case doesn't share
> any code with the one for systems with coherent caches.  Split it off
> and merge it with the helpers in dma-noncoherent.c that have no other
> callers.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Acked-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> ---
>   arch/powerpc/include/asm/dma-mapping.h |  5 -----
>   arch/powerpc/kernel/dma.c              | 14 ++------------

Instead of all the ifdefs in dma.c, couldn't we split it
in two files, ie dma.c for common parts and dma-coherence.c for specific 
stuff ?

Christophe

>   arch/powerpc/mm/dma-noncoherent.c      | 15 +++++++--------
>   arch/powerpc/platforms/44x/warp.c      |  2 +-
>   4 files changed, 10 insertions(+), 26 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
> index f2a4a7142b1e..dacd0f93f2b2 100644
> --- a/arch/powerpc/include/asm/dma-mapping.h
> +++ b/arch/powerpc/include/asm/dma-mapping.h
> @@ -39,9 +39,6 @@ extern int dma_nommu_mmap_coherent(struct device *dev,
>    * to ensure it is consistent.
>    */
>   struct device;
> -extern void *__dma_alloc_coherent(struct device *dev, size_t size,
> -				  dma_addr_t *handle, gfp_t gfp);
> -extern void __dma_free_coherent(size_t size, void *vaddr);
>   extern void __dma_sync(void *vaddr, size_t size, int direction);
>   extern void __dma_sync_page(struct page *page, unsigned long offset,
>   				 size_t size, int direction);
> @@ -52,8 +49,6 @@ extern unsigned long __dma_get_coherent_pfn(unsigned long cpu_addr);
>    * Cache coherent cores.
>    */
>   
> -#define __dma_alloc_coherent(dev, gfp, size, handle)	NULL
> -#define __dma_free_coherent(size, addr)		((void)0)
>   #define __dma_sync(addr, size, rw)		((void)0)
>   #define __dma_sync_page(pg, off, sz, rw)	((void)0)
>   
> diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
> index d442d23e182b..270b2911c437 100644
> --- a/arch/powerpc/kernel/dma.c
> +++ b/arch/powerpc/kernel/dma.c
> @@ -62,18 +62,12 @@ static int dma_nommu_dma_supported(struct device *dev, u64 mask)
>   #endif
>   }
>   
> +#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;
> -#ifdef CONFIG_NOT_COHERENT_CACHE
> -	ret = __dma_alloc_coherent(dev, size, dma_handle, flag);
> -	if (ret == NULL)
> -		return NULL;
> -	*dma_handle += get_dma_offset(dev);
> -	return ret;
> -#else
>   	struct page *page;
>   	int node = dev_to_node(dev);
>   #ifdef CONFIG_FSL_SOC
> @@ -113,19 +107,15 @@ void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
>   	*dma_handle = __pa(ret) + get_dma_offset(dev);
>   
>   	return ret;
> -#endif
>   }
>   
>   void __dma_nommu_free_coherent(struct device *dev, size_t size,
>   				void *vaddr, dma_addr_t dma_handle,
>   				unsigned long attrs)
>   {
> -#ifdef CONFIG_NOT_COHERENT_CACHE
> -	__dma_free_coherent(size, vaddr);
> -#else
>   	free_pages((unsigned long)vaddr, get_order(size));
> -#endif
>   }
> +#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,
> diff --git a/arch/powerpc/mm/dma-noncoherent.c b/arch/powerpc/mm/dma-noncoherent.c
> index b6e7b5952ab5..e955539686a4 100644
> --- a/arch/powerpc/mm/dma-noncoherent.c
> +++ b/arch/powerpc/mm/dma-noncoherent.c
> @@ -29,7 +29,7 @@
>   #include <linux/string.h>
>   #include <linux/types.h>
>   #include <linux/highmem.h>
> -#include <linux/dma-mapping.h>
> +#include <linux/dma-direct.h>
>   #include <linux/export.h>
>   
>   #include <asm/tlbflush.h>
> @@ -151,8 +151,8 @@ static struct ppc_vm_region *ppc_vm_region_find(struct ppc_vm_region *head, unsi
>    * Allocate DMA-coherent memory space and return both the kernel remapped
>    * virtual and bus address for that space.
>    */
> -void *
> -__dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
> +void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
> +		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
>   {
>   	struct page *page;
>   	struct ppc_vm_region *c;
> @@ -223,7 +223,7 @@ __dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t
>   		/*
>   		 * Set the "dma handle"
>   		 */
> -		*handle = page_to_phys(page);
> +		*dma_handle = phys_to_dma(dev, page_to_phys(page));
>   
>   		do {
>   			SetPageReserved(page);
> @@ -249,12 +249,12 @@ __dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t
>    no_page:
>   	return NULL;
>   }
> -EXPORT_SYMBOL(__dma_alloc_coherent);
>   
>   /*
>    * free a page as defined by the above mapping.
>    */
> -void __dma_free_coherent(size_t size, void *vaddr)
> +void __dma_nommu_free_coherent(struct device *dev, size_t size, void *vaddr,
> +		dma_addr_t dma_handle, unsigned long attrs)
>   {
>   	struct ppc_vm_region *c;
>   	unsigned long flags, addr;
> @@ -309,7 +309,6 @@ void __dma_free_coherent(size_t size, void *vaddr)
>   	       __func__, vaddr);
>   	dump_stack();
>   }
> -EXPORT_SYMBOL(__dma_free_coherent);
>   
>   /*
>    * make an area consistent.
> @@ -401,7 +400,7 @@ EXPORT_SYMBOL(__dma_sync_page);
>   
>   /*
>    * Return the PFN for a given cpu virtual address returned by
> - * __dma_alloc_coherent. This is used by dma_mmap_coherent()
> + * __dma_nommu_alloc_coherent. This is used by dma_mmap_coherent()
>    */
>   unsigned long __dma_get_coherent_pfn(unsigned long cpu_addr)
>   {
> diff --git a/arch/powerpc/platforms/44x/warp.c b/arch/powerpc/platforms/44x/warp.c
> index a886c2c22097..7e4f8ca19ce8 100644
> --- a/arch/powerpc/platforms/44x/warp.c
> +++ b/arch/powerpc/platforms/44x/warp.c
> @@ -47,7 +47,7 @@ static int __init warp_probe(void)
>   	if (!of_machine_is_compatible("pika,warp"))
>   		return 0;
>   
> -	/* For __dma_alloc_coherent */
> +	/* For __dma_nommu_alloc_coherent */
>   	ISA_DMA_THRESHOLD = ~0L;
>   
>   	return 1;
> 


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