common: bouncebuf: Permit passing custom alignment check function

Add extended version of the bounce_buffer_start(), which permits passing in
a custom alignment checker function for the buffer. This is useful e.g. on
systems with various DMA restrictions and where the checker function might
be more complex than a simple CPU cache alignment check.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
diff --git a/common/bouncebuf.c b/common/bouncebuf.c
index 614eb36..0ace152 100644
--- a/common/bouncebuf.c
+++ b/common/bouncebuf.c
@@ -31,17 +31,19 @@
 	return 1;
 }
 
-int bounce_buffer_start(struct bounce_buffer *state, void *data,
-			size_t len, unsigned int flags)
+int bounce_buffer_start_extalign(struct bounce_buffer *state, void *data,
+				 size_t len, unsigned int flags,
+				 size_t alignment,
+				 int (*addr_is_aligned)(struct bounce_buffer *state))
 {
 	state->user_buffer = data;
 	state->bounce_buffer = data;
 	state->len = len;
-	state->len_aligned = roundup(len, ARCH_DMA_MINALIGN);
+	state->len_aligned = roundup(len, alignment);
 	state->flags = flags;
 
-	if (!addr_aligned(state)) {
-		state->bounce_buffer = memalign(ARCH_DMA_MINALIGN,
+	if (!addr_is_aligned(state)) {
+		state->bounce_buffer = memalign(alignment,
 						state->len_aligned);
 		if (!state->bounce_buffer)
 			return -ENOMEM;
@@ -62,6 +64,14 @@
 	return 0;
 }
 
+int bounce_buffer_start(struct bounce_buffer *state, void *data,
+			size_t len, unsigned int flags)
+{
+	return bounce_buffer_start_extalign(state, data, len, flags,
+					    ARCH_DMA_MINALIGN,
+					    addr_aligned);
+}
+
 int bounce_buffer_stop(struct bounce_buffer *state)
 {
 	if (state->flags & GEN_BB_WRITE) {