summaryrefslogtreecommitdiff
path: root/common/bouncebuf.c
diff options
context:
space:
mode:
Diffstat (limited to 'common/bouncebuf.c')
-rw-r--r--common/bouncebuf.c75
1 files changed, 41 insertions, 34 deletions
diff --git a/common/bouncebuf.c b/common/bouncebuf.c
index 4f827f8..1df12cd 100644
--- a/common/bouncebuf.c
+++ b/common/bouncebuf.c
@@ -27,21 +27,19 @@
#include <errno.h>
#include <bouncebuf.h>
-static int addr_aligned(void *data, size_t len)
+static int addr_aligned(struct bounce_buffer *state)
{
const ulong align_mask = ARCH_DMA_MINALIGN - 1;
/* Check if start is aligned */
- if ((ulong)data & align_mask) {
- debug("Unaligned start address %p\n", data);
+ if ((ulong)state->user_buffer & align_mask) {
+ debug("Unaligned buffer address %p\n", state->user_buffer);
return 0;
}
- data += len;
-
- /* Check if end is aligned */
- if ((ulong)data & align_mask) {
- debug("Unaligned end address %p\n", data);
+ /* Check if length is aligned */
+ if (state->len != state->len_aligned) {
+ debug("Unaligned buffer length %d\n", state->len);
return 0;
}
@@ -49,44 +47,53 @@ static int addr_aligned(void *data, size_t len)
return 1;
}
-int bounce_buffer_start(void **data, size_t len, void **backup, uint8_t flags)
+int bounce_buffer_start(struct bounce_buffer *state, void *data,
+ size_t len, unsigned int flags)
{
- void *tmp;
- size_t alen;
-
- if (addr_aligned(*data, len)) {
- *backup = NULL;
- return 0;
+ state->user_buffer = data;
+ state->bounce_buffer = data;
+ state->len = len;
+ state->len_aligned = roundup(len, ARCH_DMA_MINALIGN);
+ state->flags = flags;
+
+ if (!addr_aligned(state)) {
+ state->bounce_buffer = memalign(ARCH_DMA_MINALIGN,
+ state->len_aligned);
+ if (!state->bounce_buffer)
+ return -ENOMEM;
+
+ if (state->flags & GEN_BB_READ)
+ memcpy(state->bounce_buffer, state->user_buffer,
+ state->len);
}
- alen = roundup(len, ARCH_DMA_MINALIGN);
- tmp = memalign(ARCH_DMA_MINALIGN, alen);
-
- if (!tmp)
- return -ENOMEM;
-
- if (flags & GEN_BB_READ)
- memcpy(tmp, *data, len);
-
- *backup = *data;
- *data = tmp;
+ /*
+ * Flush data to RAM so DMA reads can pick it up,
+ * and any CPU writebacks don't race with DMA writes
+ */
+ flush_dcache_range((unsigned long)state->bounce_buffer,
+ (unsigned long)(state->bounce_buffer) +
+ state->len_aligned);
return 0;
}
-int bounce_buffer_stop(void **data, size_t len, void **backup, uint8_t flags)
+int bounce_buffer_stop(struct bounce_buffer *state)
{
- void *tmp = *data;
+ if (state->flags & GEN_BB_WRITE) {
+ /* Invalidate cache so that CPU can see any newly DMA'd data */
+ invalidate_dcache_range((unsigned long)state->bounce_buffer,
+ (unsigned long)(state->bounce_buffer) +
+ state->len_aligned);
+ }
- /* The buffer was already aligned, since "backup" is NULL. */
- if (!*backup)
+ if (state->bounce_buffer == state->user_buffer)
return 0;
- if (flags & GEN_BB_WRITE)
- memcpy(*backup, *data, len);
+ if (state->flags & GEN_BB_WRITE)
+ memcpy(state->user_buffer, state->bounce_buffer, state->len);
- *data = *backup;
- free(tmp);
+ free(state->bounce_buffer);
return 0;
}