96f1050d3d
Bill Gatliff & David Brownell pointed out we were missing some copyrights, and licensing terms in some of the files in ./arch/blackfin, so this fixes things, and cleans them up. It also removes: - verbose GPL text(refer to the top level ./COPYING file) - file names (you are looking at the file) - bug url (it's in the ./MAINTAINERS file) - "or later" on GPL-2, when we did not have that right It also allows some Blackfin-specific assembly files to be under a BSD like license (for people to use them outside of Linux). Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
167 lines
3.7 KiB
C
167 lines
3.7 KiB
C
/*
|
|
* Dynamic DMA mapping support
|
|
*
|
|
* Copyright 2005-2009 Analog Devices Inc.
|
|
*
|
|
* Licensed under the GPL-2 or later
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/string.h>
|
|
#include <linux/bootmem.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/device.h>
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/io.h>
|
|
#include <linux/scatterlist.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/bfin-global.h>
|
|
|
|
static spinlock_t dma_page_lock;
|
|
static unsigned int *dma_page;
|
|
static unsigned int dma_pages;
|
|
static unsigned long dma_base;
|
|
static unsigned long dma_size;
|
|
static unsigned int dma_initialized;
|
|
|
|
void dma_alloc_init(unsigned long start, unsigned long end)
|
|
{
|
|
spin_lock_init(&dma_page_lock);
|
|
dma_initialized = 0;
|
|
|
|
dma_page = (unsigned int *)__get_free_page(GFP_KERNEL);
|
|
memset(dma_page, 0, PAGE_SIZE);
|
|
dma_base = PAGE_ALIGN(start);
|
|
dma_size = PAGE_ALIGN(end) - PAGE_ALIGN(start);
|
|
dma_pages = dma_size >> PAGE_SHIFT;
|
|
memset((void *)dma_base, 0, DMA_UNCACHED_REGION);
|
|
dma_initialized = 1;
|
|
|
|
printk(KERN_INFO "%s: dma_page @ 0x%p - %d pages at 0x%08lx\n", __func__,
|
|
dma_page, dma_pages, dma_base);
|
|
}
|
|
|
|
static inline unsigned int get_pages(size_t size)
|
|
{
|
|
return ((size - 1) >> PAGE_SHIFT) + 1;
|
|
}
|
|
|
|
static unsigned long __alloc_dma_pages(unsigned int pages)
|
|
{
|
|
unsigned long ret = 0, flags;
|
|
int i, count = 0;
|
|
|
|
if (dma_initialized == 0)
|
|
dma_alloc_init(_ramend - DMA_UNCACHED_REGION, _ramend);
|
|
|
|
spin_lock_irqsave(&dma_page_lock, flags);
|
|
|
|
for (i = 0; i < dma_pages;) {
|
|
if (dma_page[i++] == 0) {
|
|
if (++count == pages) {
|
|
while (count--)
|
|
dma_page[--i] = 1;
|
|
ret = dma_base + (i << PAGE_SHIFT);
|
|
break;
|
|
}
|
|
} else
|
|
count = 0;
|
|
}
|
|
spin_unlock_irqrestore(&dma_page_lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
static void __free_dma_pages(unsigned long addr, unsigned int pages)
|
|
{
|
|
unsigned long page = (addr - dma_base) >> PAGE_SHIFT;
|
|
unsigned long flags;
|
|
int i;
|
|
|
|
if ((page + pages) > dma_pages) {
|
|
printk(KERN_ERR "%s: freeing outside range.\n", __func__);
|
|
BUG();
|
|
}
|
|
|
|
spin_lock_irqsave(&dma_page_lock, flags);
|
|
for (i = page; i < page + pages; i++) {
|
|
dma_page[i] = 0;
|
|
}
|
|
spin_unlock_irqrestore(&dma_page_lock, flags);
|
|
}
|
|
|
|
void *dma_alloc_coherent(struct device *dev, size_t size,
|
|
dma_addr_t * dma_handle, gfp_t gfp)
|
|
{
|
|
void *ret;
|
|
|
|
ret = (void *)__alloc_dma_pages(get_pages(size));
|
|
|
|
if (ret) {
|
|
memset(ret, 0, size);
|
|
*dma_handle = virt_to_phys(ret);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(dma_alloc_coherent);
|
|
|
|
void
|
|
dma_free_coherent(struct device *dev, size_t size, void *vaddr,
|
|
dma_addr_t dma_handle)
|
|
{
|
|
__free_dma_pages((unsigned long)vaddr, get_pages(size));
|
|
}
|
|
EXPORT_SYMBOL(dma_free_coherent);
|
|
|
|
/*
|
|
* Dummy functions defined for some existing drivers
|
|
*/
|
|
|
|
dma_addr_t
|
|
dma_map_single(struct device *dev, void *ptr, size_t size,
|
|
enum dma_data_direction direction)
|
|
{
|
|
BUG_ON(direction == DMA_NONE);
|
|
|
|
invalidate_dcache_range((unsigned long)ptr,
|
|
(unsigned long)ptr + size);
|
|
|
|
return (dma_addr_t) ptr;
|
|
}
|
|
EXPORT_SYMBOL(dma_map_single);
|
|
|
|
int
|
|
dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
|
|
enum dma_data_direction direction)
|
|
{
|
|
int i;
|
|
|
|
BUG_ON(direction == DMA_NONE);
|
|
|
|
for (i = 0; i < nents; i++, sg++) {
|
|
sg->dma_address = (dma_addr_t) sg_virt(sg);
|
|
|
|
invalidate_dcache_range(sg_dma_address(sg),
|
|
sg_dma_address(sg) +
|
|
sg_dma_len(sg));
|
|
}
|
|
|
|
return nents;
|
|
}
|
|
EXPORT_SYMBOL(dma_map_sg);
|
|
|
|
void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
|
|
enum dma_data_direction direction)
|
|
{
|
|
BUG_ON(direction == DMA_NONE);
|
|
}
|
|
EXPORT_SYMBOL(dma_unmap_single);
|
|
|
|
void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
|
|
int nhwentries, enum dma_data_direction direction)
|
|
{
|
|
BUG_ON(direction == DMA_NONE);
|
|
}
|
|
EXPORT_SYMBOL(dma_unmap_sg);
|