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/*
* arch/xtensa/kernel/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 <linux/gfp.h>
#include <linux/module.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,gfp_t flag)
{
unsigned long ret;
unsigned long uncached = 0;
/* ignore region speicifiers */
flag &= ~(__GFP_DMA | __GFP_HIGHMEM);
if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
flag |= GFP_DMA;
ret = (unsigned long)__get_free_pages(flag, get_order(size));
if (ret == 0)
return NULL;
/* We currently don't support coherent memory outside KSEG */
BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR ||
ret > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
if (ret != 0) {
memset((void*) ret, 0, size);
uncached = ret+XCHAL_KSEG_BYPASS_VADDR-XCHAL_KSEG_CACHED_VADDR;
*handle = virt_to_bus((void*)ret);
__flush_invalidate_dcache_range(ret, size);
}
return (void*)uncached;
}
EXPORT_SYMBOL(dma_alloc_coherent);
void dma_free_coherent(struct device *hwdev, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
unsigned long addr = (unsigned long)vaddr +
XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
BUG_ON(addr < XCHAL_KSEG_CACHED_VADDR ||
addr > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
free_pages(addr, get_order(size));
}
EXPORT_SYMBOL(dma_free_coherent);
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;
}
}
EXPORT_SYMBOL(consistent_sync);
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