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[ARM] 3537/1: Rework DMA-bounce locking for finer granularity 

Patch from Kevin Hilman

This time with IRQ versions of locks.

Rework also enables compatability with realtime-preemption patch.
With the current locking via interrupt disabling, under RT,
potentially sleeping functions can be called with interrupts
disabled.

Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Kevin Hilman 2006-06-22 22:27:14 +01:00 committed by Russell King
parent fa3e686a34
commit 823588c186
1 changed files with 21 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

67
arch/arm/common/dmabounce.c
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@ -77,6 +77,8 @@ struct dmabounce_device_info {
#endif
struct dmabounce_pool small;
struct dmabounce_pool large;
rwlock_t lock;
};
static LIST_HEAD(dmabounce_devs);
@ -116,6 +118,7 @@ alloc_safe_buffer(struct dmabounce_device_info *device_info, void *ptr,
struct safe_buffer *buf;
struct dmabounce_pool *pool;
struct device *dev = device_info->dev;
unsigned long flags;
dev_dbg(dev, "%s(ptr=%p, size=%d, dir=%d)\n",
__func__, ptr, size, dir);
@ -163,8 +166,12 @@ alloc_safe_buffer(struct dmabounce_device_info *device_info, void *ptr,
print_alloc_stats(device_info);
#endif
write_lock_irqsave(&device_info->lock, flags);
list_add(&buf->node, &device_info->safe_buffers);
write_unlock_irqrestore(&device_info->lock, flags);
return buf;
}
@ -172,22 +179,32 @@ alloc_safe_buffer(struct dmabounce_device_info *device_info, void *ptr,
static inline struct safe_buffer *
find_safe_buffer(struct dmabounce_device_info *device_info, dma_addr_t safe_dma_addr)
{
struct safe_buffer *b;
struct safe_buffer *b = NULL;
unsigned long flags;
read_lock_irqsave(&device_info->lock, flags);
list_for_each_entry(b, &device_info->safe_buffers, node)
if (b->safe_dma_addr == safe_dma_addr)
return b;
break;
return NULL;
read_unlock_irqrestore(&device_info->lock, flags);
return b;
}
static inline void
free_safe_buffer(struct dmabounce_device_info *device_info, struct safe_buffer *buf)
{
unsigned long flags;
dev_dbg(device_info->dev, "%s(buf=%p)\n", __func__, buf);
write_lock_irqsave(&device_info->lock, flags);
list_del(&buf->node);
write_unlock_irqrestore(&device_info->lock, flags);
if (buf->pool)
dma_pool_free(buf->pool->pool, buf->safe, buf->safe_dma_addr);
else
@ -396,7 +413,6 @@ dma_addr_t
dma_map_single(struct device *dev, void *ptr, size_t size,
enum dma_data_direction dir)
{
unsigned long flags;
dma_addr_t dma_addr;
dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n",
@ -404,12 +420,8 @@ dma_map_single(struct device *dev, void *ptr, size_t size,
BUG_ON(dir == DMA_NONE);
local_irq_save(flags);
dma_addr = map_single(dev, ptr, size, dir);
local_irq_restore(flags);
return dma_addr;
}
@ -424,25 +436,18 @@ void
dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
enum dma_data_direction dir)
{
unsigned long flags;
dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n",
__func__, (void *) dma_addr, size, dir);
BUG_ON(dir == DMA_NONE);
local_irq_save(flags);
unmap_single(dev, dma_addr, size, dir);
local_irq_restore(flags);
}
int
dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
unsigned long flags;
int i;
dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n",
@ -450,8 +455,6 @@ dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
BUG_ON(dir == DMA_NONE);
local_irq_save(flags);
for (i = 0; i < nents; i++, sg++) {
struct page *page = sg->page;
unsigned int offset = sg->offset;
@ -462,8 +465,6 @@ dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
map_single(dev, ptr, length, dir);
}
local_irq_restore(flags);
return nents;
}
@ -471,7 +472,6 @@ void
dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
unsigned long flags;
int i;
dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n",
@ -479,55 +479,38 @@ dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
BUG_ON(dir == DMA_NONE);
local_irq_save(flags);
for (i = 0; i < nents; i++, sg++) {
dma_addr_t dma_addr = sg->dma_address;
unsigned int length = sg->length;
unmap_single(dev, dma_addr, length, dir);
}
local_irq_restore(flags);
}
void
dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_addr, size_t size,
enum dma_data_direction dir)
{
unsigned long flags;
dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n",
__func__, (void *) dma_addr, size, dir);
local_irq_save(flags);
sync_single(dev, dma_addr, size, dir);
local_irq_restore(flags);
}
void
dma_sync_single_for_device(struct device *dev, dma_addr_t dma_addr, size_t size,
enum dma_data_direction dir)
{
unsigned long flags;
dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n",
__func__, (void *) dma_addr, size, dir);
local_irq_save(flags);
sync_single(dev, dma_addr, size, dir);
local_irq_restore(flags);
}
void
dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
unsigned long flags;
int i;
dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n",
@ -535,23 +518,18 @@ dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
BUG_ON(dir == DMA_NONE);
local_irq_save(flags);
for (i = 0; i < nents; i++, sg++) {
dma_addr_t dma_addr = sg->dma_address;
unsigned int length = sg->length;
sync_single(dev, dma_addr, length, dir);
}
local_irq_restore(flags);
}
void
dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
unsigned long flags;
int i;
dev_dbg(dev, "%s(sg=%p,nents=%d,dir=%x)\n",
@ -559,16 +537,12 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
BUG_ON(dir == DMA_NONE);
local_irq_save(flags);
for (i = 0; i < nents; i++, sg++) {
dma_addr_t dma_addr = sg->dma_address;
unsigned int length = sg->length;
sync_single(dev, dma_addr, length, dir);
}
local_irq_restore(flags);
}
static int
@ -622,6 +596,7 @@ dmabounce_register_dev(struct device *dev, unsigned long small_buffer_size,
device_info->dev = dev;
INIT_LIST_HEAD(&device_info->safe_buffers);
rwlock_init(&device_info->lock);
#ifdef STATS
device_info->total_allocs = 0;