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sh: declared coherent memory support V2
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This patch adds declared coherent memory support to the sh architecture. All
functions are based on the x86 implementation. Header files are adjusted to
use the new functions instead of the former consistent_alloc() code.

This version includes the few changes what were included in the fix patch
together with modifications based on feedback from Paul.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
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Magnus Damm authored and Paul Mundt committed Jan 28, 2008
1 parent 4862ec0 commit f93e97e
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Showing 2 changed files with 148 additions and 82 deletions.
174 changes: 128 additions & 46 deletions arch/sh/mm/consistent.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,8 @@
*
* 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.
Expand All @@ -13,66 +15,146 @@
#include <asm/addrspace.h>
#include <asm/io.h>

void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle)
{
struct page *page, *end, *free;
void *ret, *vp;
int order;

size = PAGE_ALIGN(size);
order = get_order(size);
struct dma_coherent_mem {
void *virt_base;
u32 device_base;
int size;
int flags;
unsigned long *bitmap;
};

page = alloc_pages(gfp, order);
if (!page)
return NULL;
split_page(page, order);
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 = page_address(page);
*handle = virt_to_phys(ret);
ret = (void *)__get_free_pages(gfp, order);

vp = ioremap_nocache(*handle, size);
if (!vp) {
free_pages((unsigned long)ret, order);
return NULL;
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);

memset(vp, 0, size);

/*
* We must flush the cache before we pass it on to the device
*/
dma_cache_sync(NULL, ret, size, DMA_BIDIRECTIONAL);
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);

page = virt_to_page(ret);
free = page + (size >> PAGE_SHIFT);
end = page + (1 << order);
if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;

while (++page < end) {
/* Free any unused pages */
if (page >= free) {
__free_page(page);
}
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);
}

return vp;
}
EXPORT_SYMBOL(consistent_alloc);
EXPORT_SYMBOL(dma_free_coherent);

void consistent_free(void *vaddr, size_t size, dma_addr_t dma_handle)
int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
dma_addr_t device_addr, size_t size, int flags)
{
struct page *page;
unsigned long addr;

addr = (unsigned long)phys_to_virt((unsigned long)dma_handle);
page = virt_to_page(addr);
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);

free_pages(addr, get_order(size));
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);

iounmap(vaddr);
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(consistent_free);
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);

void consistent_sync(void *vaddr, size_t size, int direction)
void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction direction)
{
#ifdef CONFIG_CPU_SH5
void *p1addr = vaddr;
Expand All @@ -94,4 +176,4 @@ void consistent_sync(void *vaddr, size_t size, int direction)
BUG();
}
}
EXPORT_SYMBOL(consistent_sync);
EXPORT_SYMBOL(dma_cache_sync);
56 changes: 20 additions & 36 deletions include/asm-sh/dma-mapping.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,11 +8,6 @@

extern struct bus_type pci_bus_type;

/* arch/sh/mm/consistent.c */
extern void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle);
extern void consistent_free(void *vaddr, size_t size, dma_addr_t handle);
extern void consistent_sync(void *vaddr, size_t size, int direction);

#define dma_supported(dev, mask) (1)

static inline int dma_set_mask(struct device *dev, u64 mask)
Expand All @@ -25,44 +20,19 @@ static inline int dma_set_mask(struct device *dev, u64 mask)
return 0;
}

static inline void *dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag)
{
if (sh_mv.mv_consistent_alloc) {
void *ret;
void *dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag);

ret = sh_mv.mv_consistent_alloc(dev, size, dma_handle, flag);
if (ret != NULL)
return ret;
}

return consistent_alloc(flag, size, dma_handle);
}

static inline void dma_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
if (sh_mv.mv_consistent_free) {
int ret;

ret = sh_mv.mv_consistent_free(dev, size, vaddr, dma_handle);
if (ret == 0)
return;
}
void dma_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle);

consistent_free(vaddr, size, dma_handle);
}
void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction dir);

#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
#define dma_is_consistent(d, h) (1)

static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction dir)
{
consistent_sync(vaddr, size, (int)dir);
}

static inline dma_addr_t dma_map_single(struct device *dev,
void *ptr, size_t size,
enum dma_data_direction dir)
Expand Down Expand Up @@ -205,4 +175,18 @@ static inline int dma_mapping_error(dma_addr_t dma_addr)
{
return dma_addr == 0;
}

#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);

#endif /* __ASM_SH_DMA_MAPPING_H */

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