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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>
This commit is contained in:
Christoph Hellwig 2019-11-07 18:08:39 +01:00
parent 999a5d1203
commit a4a4d11a22
2 changed files with 12 additions and 45 deletions
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2
arch/openrisc/Kconfig
View File

@ -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

55
arch/openrisc/kernel/dma.c
View File

@ -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,