dma-mapping: use vmap insted of reimplementing it (515e5b6d) · Commits · 戴 / test

Replace the open coded instance of vmap with the actual function. In the non-contiguous (IOMMU) case this requires an extra find_vm_area, but given that this isn't a fast path function that is a small price to pay. Signed-off-by:

Christoph Hellwig <hch@lst.de> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Acked-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Gao Xiang <xiang@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Kelley <mikelley@microsoft.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Wei Liu <wei.liu@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Link: http://lkml.kernel.org/r/20200414131348.444715-6-hch@lst.de Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

kernel/dma/remap.c

+12 −36

Original line number	Diff line number	Diff line
		@@ -20,23 +20,6 @@ struct page *dma_common_find_pages(void cpu_addr)
		return area->pages;
		}

		static struct vm_struct __dma_common_pages_remap(struct page *pages,
		size_t size, pgprot_t prot, const void *caller)
		{
		struct vm_struct *area;

		area = get_vm_area_caller(size, VM_DMA_COHERENT, caller);
		if (!area)
		return NULL;

		if (map_vm_area(area, prot, pages)) {
		vunmap(area->addr);
		return NULL;
		}

		return area;
		}

		/*
		* Remaps an array of PAGE_SIZE pages into another vm_area.
		* Cannot be used in non-sleeping contexts
		@@ -44,15 +27,12 @@ static struct vm_struct __dma_common_pages_remap(struct page *pages,
		void dma_common_pages_remap(struct page *pages, size_t size,
		pgprot_t prot, const void *caller)
		{
		struct vm_struct *area;
		void *vaddr;

		area = __dma_common_pages_remap(pages, size, prot, caller);
		if (!area)
		return NULL;

		area->pages = pages;

		return area->addr;
		vaddr = vmap(pages, size >> PAGE_SHIFT, VM_DMA_COHERENT, prot);
		if (vaddr)
		find_vm_area(vaddr)->pages = pages;
		return vaddr;
		}

		/*
		@@ -62,24 +42,20 @@ void dma_common_pages_remap(struct page *pages, size_t size,
		void dma_common_contiguous_remap(struct page page, size_t size,
		pgprot_t prot, const void *caller)
		{
		int i;
		int count = size >> PAGE_SHIFT;
		struct page **pages;
		struct vm_struct *area;
		void *vaddr;
		int i;

		pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
		pages = kmalloc_array(count, sizeof(struct page *), GFP_KERNEL);
		if (!pages)
		return NULL;

		for (i = 0; i < (size >> PAGE_SHIFT); i++)
		for (i = 0; i < count; i++)
		pages[i] = nth_page(page, i);

		area = __dma_common_pages_remap(pages, size, prot, caller);

		vaddr = vmap(pages, count, VM_DMA_COHERENT, prot);
		kfree(pages);

		if (!area)
		return NULL;
		return area->addr;
		return vaddr;
		}

		/*

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