WSL2-Linux-Kernel/arch/xtensa/kernel/pci-dma.c

74 строки
1.8 KiB
C

/*
* arch/xtensa/pci-dma.c
*
* DMA coherent memory allocation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* Copyright (C) 2002 - 2005 Tensilica Inc.
*
* Based on version for i386.
*
* Chris Zankel <chris@zankel.net>
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
*/
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/pci.h>
#include <asm/io.h>
#include <asm/cacheflush.h>
/*
* Note: We assume that the full memory space is always mapped to 'kseg'
* Otherwise we have to use page attributes (not implemented).
*/
void *
dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, int gfp)
{
void *ret;
/* ignore region speicifiers */
gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
if (dev == NULL || (*dev->dma_mask < 0xffffffff))
gfp |= GFP_DMA;
ret = (void *)__get_free_pages(gfp, get_order(size));
if (ret != NULL) {
memset(ret, 0, size);
*handle = virt_to_bus(ret);
}
return (void*) BYPASS_ADDR((unsigned long)ret);
}
void dma_free_coherent(struct device *hwdev, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
free_pages(CACHED_ADDR((unsigned long)vaddr), get_order(size));
}
void consistent_sync(void *vaddr, size_t size, int direction)
{
switch (direction) {
case PCI_DMA_NONE:
BUG();
case PCI_DMA_FROMDEVICE: /* invalidate only */
__invalidate_dcache_range((unsigned long)vaddr,
(unsigned long)size);
break;
case PCI_DMA_TODEVICE: /* writeback only */
case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */
__flush_invalidate_dcache_range((unsigned long)vaddr,
(unsigned long)size);
break;
}
}