openrisc: use the generic in-place uncached DMA allocator (a4a4d11a) · Commits · 戴 / test

arch/openrisc/Kconfig

+2 −0

Original line number	Diff line number	Diff line
		@@ -7,6 +7,8 @@
		config OPENRISC
		def_bool y
		select ARCH_32BIT_OFF_T
		select ARCH_HAS_DMA_SET_UNCACHED
		select ARCH_HAS_DMA_CLEAR_UNCACHED
		select ARCH_HAS_SYNC_DMA_FOR_DEVICE
		select OF
		select OF_EARLY_FLATTREE

arch/openrisc/kernel/dma.c

+10 −45

Original line number	Diff line number	Diff line
		@@ -11,8 +11,6 @@
		* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
		*
		* DMA mapping callbacks...
		* As alloc_coherent is the only DMA callback being used currently, that's
		* the only thing implemented properly. The rest need looking into...
		*/

		#include <linux/dma-noncoherent.h>
		@@ -67,62 +65,29 @@ static const struct mm_walk_ops clear_nocache_walk_ops = {
		.pte_entry = page_clear_nocache,
		};

		/*
		* Alloc "coherent" memory, which for OpenRISC means simply uncached.
		*
		* This function effectively just calls __get_free_pages, sets the
		* cache-inhibit bit on those pages, and makes sure that the pages are
		* flushed out of the cache before they are used.
		*
		* If the NON_CONSISTENT attribute is set, then this function just
		* returns "normal", cachable memory.
		*
		* There are additional flags WEAK_ORDERING and WRITE_COMBINE to take
		* into consideration here, too. All current known implementations of
		* the OR1K support only strongly ordered memory accesses, so that flag
		* is being ignored for now; uncached but write-combined memory is a
		* missing feature of the OR1K.
		*/
		void *
		arch_dma_alloc(struct device dev, size_t size, dma_addr_t dma_handle,
		gfp_t gfp, unsigned long attrs)
		void arch_dma_set_uncached(void cpu_addr, size_t size)
		{
		unsigned long va;
		void *page;

		page = alloc_pages_exact(size, gfp \| __GFP_ZERO);
		if (!page)
		return NULL;

		/* This gives us the real physical address of the first page. */
		*dma_handle = __pa(page);

		va = (unsigned long)page;
		unsigned long va = (unsigned long)cpu_addr;
		int error;

		/*
		* We need to iterate through the pages, clearing the dcache for
		* them and setting the cache-inhibit bit.
		*/
		if (walk_page_range(&init_mm, va, va + size, &set_nocache_walk_ops,
		NULL)) {
		free_pages_exact(page, size);
		return NULL;
		error = walk_page_range(&init_mm, va, va + size, &set_nocache_walk_ops,
		NULL);
		if (error)
		return ERR_PTR(error);
		return cpu_addr;
		}

		return (void *)va;
		}

		void
		arch_dma_free(struct device dev, size_t size, void vaddr,
		dma_addr_t dma_handle, unsigned long attrs)
		void arch_dma_clear_uncached(void *cpu_addr, size_t size)
		{
		unsigned long va = (unsigned long)vaddr;
		unsigned long va = (unsigned long)cpu_addr;

		/* walk_page_range shouldn't be able to fail here */
		WARN_ON(walk_page_range(&init_mm, va, va + size,
		&clear_nocache_walk_ops, NULL));

		free_pages_exact(vaddr, size);
		}

		void arch_sync_dma_for_device(phys_addr_t addr, size_t size,

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