generic: per-device coherent dma allocator

Currently x86_32, sh and cris-v32 provide per-device coherent dma
memory allocator.

However their implementation is nearly identical. Refactor out
common code to be reused by them.

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Dmitry Baryshkov 2008-06-29 14:18:46 +04:00 committed by Ingo Molnar
parent 543cf4cb3f
commit ee7e5516be
4 changed files with 164 additions and 0 deletions

View file

@ -0,0 +1,32 @@
#ifndef DMA_COHERENT_H
#define DMA_COHERENT_H
#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
/*
* These two functions are only for dma allocator.
* Don't use them in device drivers.
*/
int dma_alloc_from_coherent(struct device *dev, ssize_t size,
dma_addr_t *dma_handle, void **ret);
int dma_release_from_coherent(struct device *dev, int order, void *vaddr);
/*
* Standard interface
*/
#define ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
extern int
dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
dma_addr_t device_addr, size_t size, int flags);
extern void
dma_release_declared_memory(struct device *dev);
extern void *
dma_mark_declared_memory_occupied(struct device *dev,
dma_addr_t device_addr, size_t size);
#else
#define dma_alloc_from_coherent(dev, size, handle, ret) (0)
#define dma_release_from_coherent(dev, order, vaddr) (0)
#endif
#endif

View file

@ -802,6 +802,10 @@ config PROC_PAGE_MONITOR
endmenu # General setup endmenu # General setup
config HAVE_GENERIC_DMA_COHERENT
bool
default n
config SLABINFO config SLABINFO
bool bool
depends on PROC_FS depends on PROC_FS

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@ -69,6 +69,7 @@ obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
obj-$(CONFIG_MARKERS) += marker.o obj-$(CONFIG_MARKERS) += marker.o
obj-$(CONFIG_LATENCYTOP) += latencytop.o obj-$(CONFIG_LATENCYTOP) += latencytop.o
obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o
ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y) ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is

127
kernel/dma-coherent.c Normal file
View file

@ -0,0 +1,127 @@
/*
* Coherent per-device memory handling.
* Borrowed from i386
*/
#include <linux/kernel.h>
#include <linux/dma-mapping.h>
struct dma_coherent_mem {
void *virt_base;
u32 device_base;
int size;
int flags;
unsigned long *bitmap;
};
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 = NULL;
int pages = size >> PAGE_SHIFT;
int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
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 = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
if (!dev->dma_mem)
goto out;
dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
if (!dev->dma_mem->bitmap)
goto free1_out;
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);
out:
if (mem_base)
iounmap(mem_base);
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 pos, err;
int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1);
pages >>= PAGE_SHIFT;
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);
int dma_alloc_from_coherent(struct device *dev, ssize_t size,
dma_addr_t *dma_handle, void **ret)
{
struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
int order = get_order(size);
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);
}
if (mem->flags & DMA_MEMORY_EXCLUSIVE)
*ret = NULL;
}
return (mem != NULL);
}
int dma_release_from_coherent(struct device *dev, int order, void *vaddr)
{
struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
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);
return 1;
}
return 0;
}