* limited DMA windows. These functions utilize bounce buffers to
* copy data to/from buffers located outside the DMA region. This
* only works for systems in which DMA memory is at the bottom of
- * RAM and the remainder of memory is at the top an the DMA memory
+ * RAM, the remainder of memory is at the top and the DMA memory
* can be marked as ZONE_DMA. Anything beyond that such as discontigous
* DMA windows will require custom implementations that reserve memory
* areas at early bootup.
#include <linux/dmapool.h>
#include <linux/list.h>
-#undef DEBUG
+#include <asm/cacheflush.h>
+#undef DEBUG
#undef STATS
+
#ifdef STATS
#define DO_STATS(X) do { X ; } while (0)
#else
int direction;
/* safe buffer info */
- struct dma_pool *pool;
+ struct dmabounce_pool *pool;
void *safe;
dma_addr_t safe_dma_addr;
};
+struct dmabounce_pool {
+ unsigned long size;
+ struct dma_pool *pool;
+#ifdef STATS
+ unsigned long allocs;
+#endif
+};
+
struct dmabounce_device_info {
struct list_head node;
struct device *dev;
- struct dma_pool *small_buffer_pool;
- struct dma_pool *large_buffer_pool;
struct list_head safe_buffers;
- unsigned long small_buffer_size, large_buffer_size;
#ifdef STATS
- unsigned long sbp_allocs;
- unsigned long lbp_allocs;
unsigned long total_allocs;
unsigned long map_op_count;
unsigned long bounce_count;
#endif
+ struct dmabounce_pool small;
+ struct dmabounce_pool large;
};
static LIST_HEAD(dmabounce_devs);
printk(KERN_INFO
"%s: dmabounce: sbp: %lu, lbp: %lu, other: %lu, total: %lu\n",
device_info->dev->bus_id,
- device_info->sbp_allocs, device_info->lbp_allocs,
- device_info->total_allocs - device_info->sbp_allocs -
- device_info->lbp_allocs,
+ device_info->small.allocs, device_info->large.allocs,
+ device_info->total_allocs - device_info->small.allocs -
+ device_info->large.allocs,
device_info->total_allocs);
}
#endif
static inline struct dmabounce_device_info *
find_dmabounce_dev(struct device *dev)
{
- struct list_head *entry;
-
- list_for_each(entry, &dmabounce_devs) {
- struct dmabounce_device_info *d =
- list_entry(entry, struct dmabounce_device_info, node);
+ struct dmabounce_device_info *d;
+ list_for_each_entry(d, &dmabounce_devs, node)
if (d->dev == dev)
return d;
- }
+
return NULL;
}
/* allocate a 'safe' buffer and keep track of it */
static inline struct safe_buffer *
alloc_safe_buffer(struct dmabounce_device_info *device_info, void *ptr,
- size_t size, enum dma_data_direction dir)
+ size_t size, enum dma_data_direction dir)
{
struct safe_buffer *buf;
- struct dma_pool *pool;
+ struct dmabounce_pool *pool;
struct device *dev = device_info->dev;
- void *safe;
- dma_addr_t safe_dma_addr;
dev_dbg(dev, "%s(ptr=%p, size=%d, dir=%d)\n",
__func__, ptr, size, dir);
- DO_STATS ( device_info->total_allocs++ );
+ if (size <= device_info->small.size) {
+ pool = &device_info->small;
+ } else if (size <= device_info->large.size) {
+ pool = &device_info->large;
+ } else {
+ pool = NULL;
+ }
buf = kmalloc(sizeof(struct safe_buffer), GFP_ATOMIC);
if (buf == NULL) {
return NULL;
}
- if (size <= device_info->small_buffer_size) {
- pool = device_info->small_buffer_pool;
- safe = dma_pool_alloc(pool, GFP_ATOMIC, &safe_dma_addr);
-
- DO_STATS ( device_info->sbp_allocs++ );
- } else if (size <= device_info->large_buffer_size) {
- pool = device_info->large_buffer_pool;
- safe = dma_pool_alloc(pool, GFP_ATOMIC, &safe_dma_addr);
+ buf->ptr = ptr;
+ buf->size = size;
+ buf->direction = dir;
+ buf->pool = pool;
- DO_STATS ( device_info->lbp_allocs++ );
+ if (pool) {
+ buf->safe = dma_pool_alloc(pool->pool, GFP_ATOMIC,
+ &buf->safe_dma_addr);
} else {
- pool = NULL;
- safe = dma_alloc_coherent(dev, size, &safe_dma_addr, GFP_ATOMIC);
+ buf->safe = dma_alloc_coherent(dev, size, &buf->safe_dma_addr,
+ GFP_ATOMIC);
}
- if (safe == NULL) {
- dev_warn(device_info->dev,
- "%s: could not alloc dma memory (size=%d)\n",
- __func__, size);
+ if (buf->safe == NULL) {
+ dev_warn(dev,
+ "%s: could not alloc dma memory (size=%d)\n",
+ __func__, size);
kfree(buf);
return NULL;
}
#ifdef STATS
+ if (pool)
+ pool->allocs++;
+ device_info->total_allocs++;
if (device_info->total_allocs % 1000 == 0)
print_alloc_stats(device_info);
#endif
- buf->ptr = ptr;
- buf->size = size;
- buf->direction = dir;
- buf->pool = pool;
- buf->safe = safe;
- buf->safe_dma_addr = safe_dma_addr;
-
list_add(&buf->node, &device_info->safe_buffers);
return buf;
static inline struct safe_buffer *
find_safe_buffer(struct dmabounce_device_info *device_info, dma_addr_t safe_dma_addr)
{
- struct list_head *entry;
-
- list_for_each(entry, &device_info->safe_buffers) {
- struct safe_buffer *b =
- list_entry(entry, struct safe_buffer, node);
+ struct safe_buffer *b;
+ list_for_each_entry(b, &device_info->safe_buffers, node)
if (b->safe_dma_addr == safe_dma_addr)
return b;
- }
return NULL;
}
list_del(&buf->node);
if (buf->pool)
- dma_pool_free(buf->pool, buf->safe, buf->safe_dma_addr);
+ dma_pool_free(buf->pool->pool, buf->safe, buf->safe_dma_addr);
else
dma_free_coherent(device_info->dev, buf->size, buf->safe,
buf->safe_dma_addr);
/* ************************************************** */
#ifdef STATS
-
static void print_map_stats(struct dmabounce_device_info *device_info)
{
- printk(KERN_INFO
- "%s: dmabounce: map_op_count=%lu, bounce_count=%lu\n",
- device_info->dev->bus_id,
+ dev_info(device_info->dev,
+ "dmabounce: map_op_count=%lu, bounce_count=%lu\n",
device_info->map_op_count, device_info->bounce_count);
}
#endif
__func__, ptr, buf->safe, size);
memcpy(buf->safe, ptr, size);
}
- consistent_sync(buf->safe, size, dir);
+ ptr = buf->safe;
dma_addr = buf->safe_dma_addr;
- } else {
- consistent_sync(ptr, size, dir);
}
+ consistent_sync(ptr, size, dir);
+
return dma_addr;
}
/*
* Trying to unmap an invalid mapping
*/
- if (dma_addr == ~0) {
+ if (dma_mapping_error(dma_addr)) {
dev_err(dev, "Trying to unmap invalid mapping\n");
return;
}
__func__, buf->ptr, (void *) virt_to_dma(dev, buf->ptr),
buf->safe, (void *) buf->safe_dma_addr);
-
DO_STATS ( device_info->bounce_count++ );
- if ((dir == DMA_FROM_DEVICE) ||
- (dir == DMA_BIDIRECTIONAL)) {
+ if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) {
+ unsigned long ptr;
+
dev_dbg(dev,
"%s: copy back safe %p to unsafe %p size %d\n",
__func__, buf->safe, buf->ptr, size);
memcpy(buf->ptr, buf->safe, size);
+
+ /*
+ * DMA buffers must have the same cache properties
+ * as if they were really used for DMA - which means
+ * data must be written back to RAM. Note that
+ * we don't use dmac_flush_range() here for the
+ * bidirectional case because we know the cache
+ * lines will be coherent with the data written.
+ */
+ ptr = (unsigned long)buf->ptr;
+ dmac_clean_range(ptr, ptr + size);
}
free_safe_buffer(device_info, buf);
}
local_irq_restore(flags);
}
+static int
+dmabounce_init_pool(struct dmabounce_pool *pool, struct device *dev, const char *name,
+ unsigned long size)
+{
+ pool->size = size;
+ DO_STATS(pool->allocs = 0);
+ pool->pool = dma_pool_create(name, dev, size,
+ 0 /* byte alignment */,
+ 0 /* no page-crossing issues */);
+
+ return pool->pool ? 0 : -ENOMEM;
+}
+
int
dmabounce_register_dev(struct device *dev, unsigned long small_buffer_size,
unsigned long large_buffer_size)
{
struct dmabounce_device_info *device_info;
+ int ret;
device_info = kmalloc(sizeof(struct dmabounce_device_info), GFP_ATOMIC);
if (!device_info) {
return -ENOMEM;
}
- device_info->small_buffer_pool =
- dma_pool_create("small_dmabounce_pool",
- dev,
- small_buffer_size,
- 0 /* byte alignment */,
- 0 /* no page-crossing issues */);
- if (!device_info->small_buffer_pool) {
- printk(KERN_ERR
- "dmabounce: could not allocate small DMA pool for %s\n",
- dev->bus_id);
- kfree(device_info);
- return -ENOMEM;
+ ret = dmabounce_init_pool(&device_info->small, dev,
+ "small_dmabounce_pool", small_buffer_size);
+ if (ret) {
+ dev_err(dev,
+ "dmabounce: could not allocate DMA pool for %ld byte objects\n",
+ small_buffer_size);
+ goto err_free;
}
if (large_buffer_size) {
- device_info->large_buffer_pool =
- dma_pool_create("large_dmabounce_pool",
- dev,
- large_buffer_size,
- 0 /* byte alignment */,
- 0 /* no page-crossing issues */);
- if (!device_info->large_buffer_pool) {
- printk(KERN_ERR
- "dmabounce: could not allocate large DMA pool for %s\n",
- dev->bus_id);
- dma_pool_destroy(device_info->small_buffer_pool);
-
- return -ENOMEM;
+ ret = dmabounce_init_pool(&device_info->large, dev,
+ "large_dmabounce_pool",
+ large_buffer_size);
+ if (ret) {
+ dev_err(dev,
+ "dmabounce: could not allocate DMA pool for %ld byte objects\n",
+ large_buffer_size);
+ goto err_destroy;
}
}
device_info->dev = dev;
- device_info->small_buffer_size = small_buffer_size;
- device_info->large_buffer_size = large_buffer_size;
INIT_LIST_HEAD(&device_info->safe_buffers);
#ifdef STATS
- device_info->sbp_allocs = 0;
- device_info->lbp_allocs = 0;
device_info->total_allocs = 0;
device_info->map_op_count = 0;
device_info->bounce_count = 0;
dev->bus_id, dev->bus->name);
return 0;
+
+ err_destroy:
+ dma_pool_destroy(device_info->small.pool);
+ err_free:
+ kfree(device_info);
+ return ret;
}
void
BUG();
}
- if (device_info->small_buffer_pool)
- dma_pool_destroy(device_info->small_buffer_pool);
- if (device_info->large_buffer_pool)
- dma_pool_destroy(device_info->large_buffer_pool);
+ if (device_info->small.pool)
+ dma_pool_destroy(device_info->small.pool);
+ if (device_info->large.pool)
+ dma_pool_destroy(device_info->large.pool);
#ifdef STATS
print_alloc_stats(device_info);
git://git.onelab.eu / linux-2.6.git / blobdiff