1 files changed, 92 insertions, 0 deletions
diff --git a/src/drivers/storage/bouncebuf.c b/src/drivers/storage/bouncebuf.c
new file mode 100644
index 0000000000..c8125aaa42
--- /dev/null
+++ b/src/drivers/storage/bouncebuf.c
@@ -0,0 +1,92 @@
+/*
+ * Generic bounce buffer implementation
+ *
+ * Copyright (C) 2012 Marek Vasut <marex@denx.de>
+ * Copyright 2013 Google Inc.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/cache.h>
+#include <console/console.h>
+#include "bouncebuf.h"
+#include <halt.h>
+#include "storage.h"
+#include <string.h>
+#include <commonlib/stdlib.h>
+
+static int addr_aligned(struct bounce_buffer *state)
+{
+	const uint32_t align_mask = ARCH_DMA_MINALIGN - 1;
+
+	// Check if start is aligned
+	if ((uintptr_t)state->user_buffer & align_mask) {
+		sdhc_debug("Unaligned buffer address %p\n", state->user_buffer);
+		return 0;
+	}
+
+	// Check if length is aligned
+	if (state->len != state->len_aligned) {
+		sdhc_debug("Unaligned buffer length %zd\n", state->len);
+		return 0;
+	}
+
+	// Aligned
+	return 1;
+}
+
+int bounce_buffer_start(struct bounce_buffer *state, void *data,
+			size_t len, unsigned int flags)
+{
+	state->user_buffer = data;
+	state->bounce_buffer = data;
+	state->len = len;
+	state->len_aligned = ROUND(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 -1;
+
+		if (state->flags & GEN_BB_READ)
+			memcpy(state->bounce_buffer, state->user_buffer,
+				state->len);
+	}
+
+	/*
+	 * Flush data to RAM so DMA reads can pick it up,
+	 * and any CPU writebacks don't race with DMA writes
+	 */
+	dcache_clean_invalidate_by_mva(state->bounce_buffer,
+				       state->len_aligned);
+	return 0;
+}
+
+int bounce_buffer_stop(struct bounce_buffer *state)
+{
+	if (state->flags & GEN_BB_WRITE) {
+		// Invalidate cache so that CPU can see any newly DMA'd data
+		dcache_invalidate_by_mva(state->bounce_buffer,
+					 state->len_aligned);
+	}
+
+	if (state->bounce_buffer == state->user_buffer)
+		return 0;
+
+	if (state->flags & GEN_BB_WRITE)
+		memcpy(state->user_buffer, state->bounce_buffer, state->len);
+
+	free(state->bounce_buffer);
+
+	return 0;
+}