consistent.c
3.63 KB
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/*
* arch/sh/mm/consistent.c
*
* Copyright (C) 2004 - 2007 Paul Mundt
*
* Declared coherent memory functions based on arch/x86/kernel/pci-dma_32.c
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/dma-debug.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/gfp.h>
#include <asm/cacheflush.h>
#include <asm/addrspace.h>
#define PREALLOC_DMA_DEBUG_ENTRIES 4096
struct dma_map_ops *dma_ops;
EXPORT_SYMBOL(dma_ops);
static int __init dma_init(void)
{
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
return 0;
}
fs_initcall(dma_init);
void *dma_generic_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp,
struct dma_attrs *attrs)
{
void *ret, *ret_nocache;
int order = get_order(size);
gfp |= __GFP_ZERO;
ret = (void *)__get_free_pages(gfp, order);
if (!ret)
return NULL;
/*
* Pages from the page allocator may have data present in
* cache. So flush the cache before using uncached memory.
*/
dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);
ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size);
if (!ret_nocache) {
free_pages((unsigned long)ret, order);
return NULL;
}
split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
*dma_handle = virt_to_phys(ret);
return ret_nocache;
}
void dma_generic_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
int order = get_order(size);
unsigned long pfn = dma_handle >> PAGE_SHIFT;
int k;
for (k = 0; k < (1 << order); k++)
__free_pages(pfn_to_page(pfn + k), 0);
iounmap(vaddr);
}
void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction direction)
{
void *addr;
addr = __in_29bit_mode() ?
(void *)CAC_ADDR((unsigned long)vaddr) : vaddr;
switch (direction) {
case DMA_FROM_DEVICE: /* invalidate only */
__flush_invalidate_region(addr, size);
break;
case DMA_TO_DEVICE: /* writeback only */
__flush_wback_region(addr, size);
break;
case DMA_BIDIRECTIONAL: /* writeback and invalidate */
__flush_purge_region(addr, size);
break;
default:
BUG();
}
}
EXPORT_SYMBOL(dma_cache_sync);
static int __init memchunk_setup(char *str)
{
return 1; /* accept anything that begins with "memchunk." */
}
__setup("memchunk.", memchunk_setup);
static void __init memchunk_cmdline_override(char *name, unsigned long *sizep)
{
char *p = boot_command_line;
int k = strlen(name);
while ((p = strstr(p, "memchunk."))) {
p += 9; /* strlen("memchunk.") */
if (!strncmp(name, p, k) && p[k] == '=') {
p += k + 1;
*sizep = memparse(p, NULL);
pr_info("%s: forcing memory chunk size to 0x%08lx\n",
name, *sizep);
break;
}
}
}
int __init platform_resource_setup_memory(struct platform_device *pdev,
char *name, unsigned long memsize)
{
struct resource *r;
dma_addr_t dma_handle;
void *buf;
r = pdev->resource + pdev->num_resources - 1;
if (r->flags) {
pr_warning("%s: unable to find empty space for resource\n",
name);
return -EINVAL;
}
memchunk_cmdline_override(name, &memsize);
if (!memsize)
return 0;
buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
if (!buf) {
pr_warning("%s: unable to allocate memory\n", name);
return -ENOMEM;
}
memset(buf, 0, memsize);
r->flags = IORESOURCE_MEM;
r->start = dma_handle;
r->end = r->start + memsize - 1;
r->name = name;
return 0;
}