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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/dma-mapping.h>
#include <asm/cacheflush.h>
#include <asm/addrspace.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);
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;
}
ret = (void *)__get_free_pages(gfp, order);
if (ret != NULL) {
memset(ret, 0, size);
/*
* Pages from the page allocator may have data present in
* cache. So flush the cache before using uncached memory.
*/
dma_cache_sync(NULL, ret, size, DMA_BIDIRECTIONAL);
*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 {
WARN_ON(irqs_disabled()); /* for portability */
BUG_ON(mem && mem->flags & DMA_MEMORY_EXCLUSIVE);
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 = 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_nocache(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;
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 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);
void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction direction)
{
#ifdef CONFIG_CPU_SH5
void *p1addr = vaddr;
#else
void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
#endif
switch (direction) {
case DMA_FROM_DEVICE: /* invalidate only */
__flush_invalidate_region(p1addr, size);
break;
case DMA_TO_DEVICE: /* writeback only */
__flush_wback_region(p1addr, size);
break;
case DMA_BIDIRECTIONAL: /* writeback and invalidate */
__flush_purge_region(p1addr, size);
break;
default:
BUG();
}
}
EXPORT_SYMBOL(dma_cache_sync);
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