kernel-ark/arch/i386/kernel/pci-dma.c
Al Viro dd0fc66fb3 [PATCH] gfp flags annotations - part 1
- added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-08 15:00:57 -07:00

151 lines
3.7 KiB
C

/*
* Dynamic DMA mapping support.
*
* On i386 there is no hardware dynamic DMA address translation,
* so consistent alloc/free are merely page allocation/freeing.
* The rest of the dynamic DMA mapping interface is implemented
* in asm/pci.h.
*/
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/pci.h>
#include <linux/module.h>
#include <asm/io.h>
struct dma_coherent_mem {
void *virt_base;
u32 device_base;
int size;
int flags;
unsigned long *bitmap;
};
void *dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp)
{
void *ret;
struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
int order = get_order(size);
/* ignore region specifiers */
gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
if (mem) {
int page = bitmap_find_free_region(mem->bitmap, mem->size,
order);
if (page >= 0) {
*dma_handle = mem->device_base + (page << PAGE_SHIFT);
ret = mem->virt_base + (page << PAGE_SHIFT);
memset(ret, 0, size);
return ret;
}
if (mem->flags & DMA_MEMORY_EXCLUSIVE)
return NULL;
}
if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
gfp |= GFP_DMA;
ret = (void *)__get_free_pages(gfp, order);
if (ret != NULL) {
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)
{
struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
int order = get_order(size);
if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
bitmap_release_region(mem->bitmap, page, order);
} else
free_pages((unsigned long)vaddr, order);
}
EXPORT_SYMBOL(dma_free_coherent);
int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
dma_addr_t device_addr, size_t size, int flags)
{
void __iomem *mem_base;
int pages = size >> PAGE_SHIFT;
int bitmap_size = (pages + 31)/32;
if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
goto out;
if (!size)
goto out;
if (dev->dma_mem)
goto out;
/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
mem_base = ioremap(bus_addr, size);
if (!mem_base)
goto out;
dev->dma_mem = kmalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
if (!dev->dma_mem)
goto out;
memset(dev->dma_mem, 0, sizeof(struct dma_coherent_mem));
dev->dma_mem->bitmap = kmalloc(bitmap_size, GFP_KERNEL);
if (!dev->dma_mem->bitmap)
goto free1_out;
memset(dev->dma_mem->bitmap, 0, bitmap_size);
dev->dma_mem->virt_base = mem_base;
dev->dma_mem->device_base = device_addr;
dev->dma_mem->size = pages;
dev->dma_mem->flags = flags;
if (flags & DMA_MEMORY_MAP)
return DMA_MEMORY_MAP;
return DMA_MEMORY_IO;
free1_out:
kfree(dev->dma_mem->bitmap);
out:
return 0;
}
EXPORT_SYMBOL(dma_declare_coherent_memory);
void dma_release_declared_memory(struct device *dev)
{
struct dma_coherent_mem *mem = dev->dma_mem;
if(!mem)
return;
dev->dma_mem = NULL;
iounmap(mem->virt_base);
kfree(mem->bitmap);
kfree(mem);
}
EXPORT_SYMBOL(dma_release_declared_memory);
void *dma_mark_declared_memory_occupied(struct device *dev,
dma_addr_t device_addr, size_t size)
{
struct dma_coherent_mem *mem = dev->dma_mem;
int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1) >> PAGE_SHIFT;
int pos, err;
if (!mem)
return ERR_PTR(-EINVAL);
pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
if (err != 0)
return ERR_PTR(err);
return mem->virt_base + (pos << PAGE_SHIFT);
}
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);