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authorChristoph Hellwig <hch@lst.de>2019-11-07 18:08:39 +0100
committerChristoph Hellwig <hch@lst.de>2020-03-16 10:48:16 +0100
commita4a4d11a22ee89d0e94bd8640ec190d81b4c8134 (patch)
tree2de28b62a9e97c61f59f79b1497fd9772be25830 /arch/openrisc/kernel
parent999a5d1203baa7cff00586361feae263ee3f23a5 (diff)
openrisc: use the generic in-place uncached DMA allocator
Switch openrisc to use the dma-direct allocator and just provide the hooks for setting memory uncached or cached. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Stafford Horne <shorne@gmail.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Diffstat (limited to 'arch/openrisc/kernel')
-rw-r--r--arch/openrisc/kernel/dma.c55
1 files changed, 10 insertions, 45 deletions
diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c
index adec711ad39d..c152a68811dd 100644
--- a/arch/openrisc/kernel/dma.c
+++ b/arch/openrisc/kernel/dma.c
@@ -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;
- }
-
- return (void *)va;
+ error = walk_page_range(&init_mm, va, va + size, &set_nocache_walk_ops,
+ NULL);
+ if (error)
+ return ERR_PTR(error);
+ return cpu_addr;
}
-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,