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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* DMA coherent memory allocation.
*
* Copyright (C) 2002 - 2005 Tensilica Inc.
* Copyright (C) 2015 Cadence Design Systems Inc.
*
* Based on version for i386.
*
* Chris Zankel <chris@zankel.net>
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
*/
#include <linux/dma-contiguous.h>
#include <linux/dma-noncoherent.h>
#include <linux/dma-direct.h>
#include <linux/gfp.h>
#include <linux/highmem.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <asm/cacheflush.h>
#include <asm/io.h>
#include <asm/platform.h>
static void do_cache_op(phys_addr_t paddr, size_t size,
void (*fn)(unsigned long, unsigned long))
{
unsigned long off = paddr & (PAGE_SIZE - 1);
unsigned long pfn = PFN_DOWN(paddr);
struct page *page = pfn_to_page(pfn);
if (!PageHighMem(page))
fn((unsigned long)phys_to_virt(paddr), size);
else
while (size > 0) {
size_t sz = min_t(size_t, size, PAGE_SIZE - off);
void *vaddr = kmap_atomic(page);
fn((unsigned long)vaddr + off, sz);
kunmap_atomic(vaddr);
off = 0;
++page;
size -= sz;
}
}
void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
size_t size, enum dma_data_direction dir)
{
switch (dir) {
case DMA_BIDIRECTIONAL:
case DMA_FROM_DEVICE:
do_cache_op(paddr, size, __invalidate_dcache_range);
break;
case DMA_NONE:
BUG();
break;
default:
break;
}
}
void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
size_t size, enum dma_data_direction dir)
{
switch (dir) {
case DMA_BIDIRECTIONAL:
case DMA_TO_DEVICE:
if (XCHAL_DCACHE_IS_WRITEBACK)
do_cache_op(paddr, size, __flush_dcache_range);
break;
case DMA_NONE:
BUG();
break;
default:
break;
}
}
void arch_dma_prep_coherent(struct page *page, size_t size)
{
__invalidate_dcache_range((unsigned long)page_address(page), size);
}
/*
* Memory caching is platform-dependent in noMMU xtensa configurations.
* The following two functions should be implemented in platform code
* in order to enable coherent DMA memory operations when CONFIG_MMU is not
* enabled.
*/
#ifdef CONFIG_MMU
void *uncached_kernel_address(void *p)
{
return p + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR;
}
void *cached_kernel_address(void *p)
{
return p + XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
}
#endif /* CONFIG_MMU */
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