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/*
* 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.
* 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;
}
}
#ifdef CONFIG_MMU
bool platform_vaddr_cached(const void *p)
{
unsigned long addr = (unsigned long)p;
return addr >= XCHAL_KSEG_CACHED_VADDR &&
addr - XCHAL_KSEG_CACHED_VADDR < XCHAL_KSEG_SIZE;
}
bool platform_vaddr_uncached(const void *p)
{
unsigned long addr = (unsigned long)p;
return addr >= XCHAL_KSEG_BYPASS_VADDR &&
addr - XCHAL_KSEG_BYPASS_VADDR < XCHAL_KSEG_SIZE;
}
void *platform_vaddr_to_uncached(void *p)
{
return p + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR;
}
void *platform_vaddr_to_cached(void *p)
{
return p + XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
}
#else
bool __attribute__((weak)) platform_vaddr_cached(const void *p)
{
WARN_ONCE(1, "Default %s implementation is used\n", __func__);
return true;
}
bool __attribute__((weak)) platform_vaddr_uncached(const void *p)
{
WARN_ONCE(1, "Default %s implementation is used\n", __func__);
return false;
}
void __attribute__((weak)) *platform_vaddr_to_uncached(void *p)
{
WARN_ONCE(1, "Default %s implementation is used\n", __func__);
return p;
}
void __attribute__((weak)) *platform_vaddr_to_cached(void *p)
{
WARN_ONCE(1, "Default %s implementation is used\n", __func__);
return p;
}
#endif
/*
* Note: We assume that the full memory space is always mapped to 'kseg'
* Otherwise we have to use page attributes (not implemented).
*/
void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
gfp_t flag, unsigned long attrs)
{
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
struct page *page = NULL;
/* ignore region speicifiers */
flag &= ~(__GFP_DMA | __GFP_HIGHMEM);
if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
flag |= GFP_DMA;
if (gfpflags_allow_blocking(flag))
page = dma_alloc_from_contiguous(dev, count, get_order(size),
flag & __GFP_NOWARN);
if (!page)
page = alloc_pages(flag | __GFP_ZERO, get_order(size));
if (!page)
return NULL;
*handle = phys_to_dma(dev, page_to_phys(page));
if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) {
return page;
}
#ifdef CONFIG_MMU
if (PageHighMem(page)) {
void *p;
p = dma_common_contiguous_remap(page, size, VM_MAP,
pgprot_noncached(PAGE_KERNEL),
__builtin_return_address(0));
if (!p) {
if (!dma_release_from_contiguous(dev, page, count))
__free_pages(page, get_order(size));
}
return p;
}
#endif
BUG_ON(!platform_vaddr_cached(page_address(page)));
__invalidate_dcache_range((unsigned long)page_address(page), size);
return platform_vaddr_to_uncached(page_address(page));
}
void arch_dma_free(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, unsigned long attrs)
{
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
struct page *page;
if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) {
page = vaddr;
} else if (platform_vaddr_uncached(vaddr)) {
page = virt_to_page(platform_vaddr_to_cached(vaddr));
} else {
#ifdef CONFIG_MMU
dma_common_free_remap(vaddr, size, VM_MAP);
#endif
page = pfn_to_page(PHYS_PFN(dma_to_phys(dev, dma_handle)));
}
if (!dma_release_from_contiguous(dev, page, count))
__free_pages(page, get_order(size));
}
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