linux/arch/nios2/mm/dma-mapping.c
Christoph Hellwig fa7e2247c5 dma-direct: make uncached_kernel_address more general
Rename the symbol to arch_dma_set_uncached, and pass a size to it as
well as allow an error return.  That will allow reusing this hook for
in-place pagetable remapping.

As the in-place remap doesn't always require an explicit cache flush,
also detangle ARCH_HAS_DMA_PREP_COHERENT from ARCH_HAS_DMA_SET_UNCACHED.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2020-03-16 10:48:09 +01:00

78 lines
1.8 KiB
C

/*
* Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
* Copyright (C) 2009 Wind River Systems Inc
* Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
*
* Based on DMA code from MIPS.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/cache.h>
#include <asm/cacheflush.h>
void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
enum dma_data_direction dir)
{
void *vaddr = phys_to_virt(paddr);
switch (dir) {
case DMA_FROM_DEVICE:
invalidate_dcache_range((unsigned long)vaddr,
(unsigned long)(vaddr + size));
break;
case DMA_TO_DEVICE:
/*
* We just need to flush the caches here , but Nios2 flush
* instruction will do both writeback and invalidate.
*/
case DMA_BIDIRECTIONAL: /* flush and invalidate */
flush_dcache_range((unsigned long)vaddr,
(unsigned long)(vaddr + size));
break;
default:
BUG();
}
}
void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
enum dma_data_direction dir)
{
void *vaddr = phys_to_virt(paddr);
switch (dir) {
case DMA_BIDIRECTIONAL:
case DMA_FROM_DEVICE:
invalidate_dcache_range((unsigned long)vaddr,
(unsigned long)(vaddr + size));
break;
case DMA_TO_DEVICE:
break;
default:
BUG();
}
}
void arch_dma_prep_coherent(struct page *page, size_t size)
{
unsigned long start = (unsigned long)page_address(page);
flush_dcache_range(start, start + size);
}
void *arch_dma_set_uncached(void *ptr, size_t size)
{
unsigned long addr = (unsigned long)ptr;
addr |= CONFIG_NIOS2_IO_REGION_BASE;
return (void *)ptr;
}