125 строки
3.2 KiB
C
125 строки
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* PowerPC version derived from arch/arm/mm/consistent.c
|
|
* Copyright (C) 2001 Dan Malek (dmalek@jlc.net)
|
|
*
|
|
* Copyright (C) 2000 Russell King
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/types.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/dma-direct.h>
|
|
#include <linux/dma-noncoherent.h>
|
|
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/dma.h>
|
|
|
|
/*
|
|
* make an area consistent.
|
|
*/
|
|
static void __dma_sync(void *vaddr, size_t size, int direction)
|
|
{
|
|
unsigned long start = (unsigned long)vaddr;
|
|
unsigned long end = start + size;
|
|
|
|
switch (direction) {
|
|
case DMA_NONE:
|
|
BUG();
|
|
case DMA_FROM_DEVICE:
|
|
/*
|
|
* invalidate only when cache-line aligned otherwise there is
|
|
* the potential for discarding uncommitted data from the cache
|
|
*/
|
|
if ((start | end) & (L1_CACHE_BYTES - 1))
|
|
flush_dcache_range(start, end);
|
|
else
|
|
invalidate_dcache_range(start, end);
|
|
break;
|
|
case DMA_TO_DEVICE: /* writeback only */
|
|
clean_dcache_range(start, end);
|
|
break;
|
|
case DMA_BIDIRECTIONAL: /* writeback and invalidate */
|
|
flush_dcache_range(start, end);
|
|
break;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
/*
|
|
* __dma_sync_page() implementation for systems using highmem.
|
|
* In this case, each page of a buffer must be kmapped/kunmapped
|
|
* in order to have a virtual address for __dma_sync(). This must
|
|
* not sleep so kmap_atomic()/kunmap_atomic() are used.
|
|
*
|
|
* Note: yes, it is possible and correct to have a buffer extend
|
|
* beyond the first page.
|
|
*/
|
|
static inline void __dma_sync_page_highmem(struct page *page,
|
|
unsigned long offset, size_t size, int direction)
|
|
{
|
|
size_t seg_size = min((size_t)(PAGE_SIZE - offset), size);
|
|
size_t cur_size = seg_size;
|
|
unsigned long flags, start, seg_offset = offset;
|
|
int nr_segs = 1 + ((size - seg_size) + PAGE_SIZE - 1)/PAGE_SIZE;
|
|
int seg_nr = 0;
|
|
|
|
local_irq_save(flags);
|
|
|
|
do {
|
|
start = (unsigned long)kmap_atomic(page + seg_nr) + seg_offset;
|
|
|
|
/* Sync this buffer segment */
|
|
__dma_sync((void *)start, seg_size, direction);
|
|
kunmap_atomic((void *)start);
|
|
seg_nr++;
|
|
|
|
/* Calculate next buffer segment size */
|
|
seg_size = min((size_t)PAGE_SIZE, size - cur_size);
|
|
|
|
/* Add the segment size to our running total */
|
|
cur_size += seg_size;
|
|
seg_offset = 0;
|
|
} while (seg_nr < nr_segs);
|
|
|
|
local_irq_restore(flags);
|
|
}
|
|
#endif /* CONFIG_HIGHMEM */
|
|
|
|
/*
|
|
* __dma_sync_page makes memory consistent. identical to __dma_sync, but
|
|
* takes a struct page instead of a virtual address
|
|
*/
|
|
static void __dma_sync_page(phys_addr_t paddr, size_t size, int dir)
|
|
{
|
|
struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
|
|
unsigned offset = paddr & ~PAGE_MASK;
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
__dma_sync_page_highmem(page, offset, size, dir);
|
|
#else
|
|
unsigned long start = (unsigned long)page_address(page) + offset;
|
|
__dma_sync((void *)start, size, dir);
|
|
#endif
|
|
}
|
|
|
|
void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
|
|
enum dma_data_direction dir)
|
|
{
|
|
__dma_sync_page(paddr, size, dir);
|
|
}
|
|
|
|
void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
|
|
enum dma_data_direction dir)
|
|
{
|
|
__dma_sync_page(paddr, size, dir);
|
|
}
|
|
|
|
void arch_dma_prep_coherent(struct page *page, size_t size)
|
|
{
|
|
unsigned long kaddr = (unsigned long)page_address(page);
|
|
|
|
flush_dcache_range(kaddr, kaddr + size);
|
|
}
|