sparse: Implement storage abstraction

The current sparse image parser relies heavily on the MMC layer, and
doesn't allow any other kind of storage medium to be used.

Rework the parser to support any kind of storage medium, as long as there
is an implementation for it.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/common/aboot.c b/common/aboot.c
index 5f5fb6b..6c35d82 100644
--- a/common/aboot.c
+++ b/common/aboot.c
@@ -58,6 +58,13 @@
 	return chunk->total_sz - sparse->chunk_hdr_sz;
 }
 
+static unsigned int sparse_block_size_to_storage(unsigned int size,
+						 sparse_storage_t *storage,
+						 sparse_header_t *sparse)
+{
+	return size * sparse->blk_sz / storage->block_sz;
+}
+
 static bool sparse_chunk_has_buffer(chunk_header_t *chunk)
 {
 	switch (chunk->chunk_type) {
@@ -257,20 +264,26 @@
 	free(buffer);
 }
 
-int write_sparse_image(block_dev_desc_t *dev_desc,
-		       disk_partition_t *info, const char *part_name,
-		       void *data, unsigned sz)
+int store_sparse_image(sparse_storage_t *storage,
+		       void *storage_priv, void *data)
 {
-	lbaint_t start;
-	lbaint_t blkcnt;
 	unsigned int chunk, offset;
 	sparse_header_t *sparse_header;
 	chunk_header_t *chunk_header;
 	sparse_buffer_t *buffer;
+	uint32_t start;
 	uint32_t total_blocks = 0;
 	uint32_t skipped = 0;
 	int i;
 
+	debug("=== Storage ===\n");
+	debug("name: %s\n", storage->name);
+	debug("block_size: 0x%x\n", storage->block_sz);
+	debug("start: 0x%x\n", storage->start);
+	debug("size: 0x%x\n", storage->size);
+	debug("write: 0x%p\n", storage->write);
+	debug("priv: 0x%p\n", storage_priv);
+
 	sparse_header = sparse_parse_header(&data);
 	if (!sparse_header) {
 		printf("sparse header issue\n");
@@ -281,7 +294,7 @@
 	 * Verify that the sparse block size is a multiple of our
 	 * storage backend block size
 	 */
-	div_u64_rem(sparse_header->blk_sz, info->blksz, &offset);
+	div_u64_rem(sparse_header->blk_sz, storage->block_sz, &offset);
 	if (offset) {
 		printf("%s: Sparse image block size issue [%u]\n",
 		       __func__, sparse_header->blk_sz);
@@ -291,8 +304,10 @@
 	puts("Flashing Sparse Image\n");
 
 	/* Start processing chunks */
-	start = info->start;
+	start = storage->start;
 	for (chunk = 0; chunk < sparse_header->total_chunks; chunk++) {
+		uint32_t blkcnt;
+
 		chunk_header = sparse_parse_chunk(sparse_header, &data);
 		if (!chunk_header) {
 			printf("Unknown chunk type");
@@ -304,20 +319,22 @@
 		 * and go on parsing the rest of the chunks
 		 */
 		if (chunk_header->chunk_type == CHUNK_TYPE_DONT_CARE) {
-			skipped += chunk_header->chunk_sz;
+			skipped += sparse_block_size_to_storage(chunk_header->chunk_sz,
+								storage,
+								sparse_header);
 			continue;
 		}
 
 		/* Retrieve the buffer we're going to write */
 		buffer = sparse_get_data_buffer(sparse_header, chunk_header,
-						info->blksz, &data);
+						storage->block_sz, &data);
 		if (!buffer)
 			continue;
 
-		blkcnt = (buffer->length / info->blksz) * buffer->repeat;
+		blkcnt = (buffer->length / storage->block_sz) * buffer->repeat;
 
 		if ((start + total_blocks + blkcnt) >
-		    (info->start + info->size)) {
+		    (storage->start + storage->size)) {
 			printf("%s: Request would exceed partition size!\n",
 			       __func__);
 			return -EINVAL;
@@ -325,30 +342,36 @@
 
 		for (i = 0; i < buffer->repeat; i++) {
 			unsigned long buffer_blk_cnt;
-			unsigned long buffer_blks;
+			int ret;
 
-			buffer_blk_cnt = buffer->length / info->blksz;
+			buffer_blk_cnt = buffer->length / storage->block_sz;
 
-			buffer_blks = dev_desc->block_write(dev_desc->dev,
-							    start + total_blocks,
-							    buffer_blk_cnt, buffer->data);
-			if (buffer_blks != buffer_blk_cnt) {
-				printf("%s: Write %d failed " LBAFU "\n",
-				       __func__, i, buffer_blks);
-				return -EIO;
+			ret = storage->write(storage, storage_priv,
+					     start + total_blocks,
+					     buffer_blk_cnt,
+					     buffer->data);
+			if (ret < 0) {
+				printf("%s: Write %d failed %d\n",
+				       __func__, i, ret);
+				return ret;
 			}
 
-			total_blocks += buffer_blk_cnt;
+			total_blocks += ret;
 		}
 
 		sparse_put_data_buffer(buffer);
 	}
 
 	debug("Wrote %d blocks, skipped %d, expected to write %d blocks\n",
-	      total_blocks, skipped, sparse_header->total_blks);
-	printf("........ wrote %d blocks to '%s'\n", total_blocks, part_name);
+	      total_blocks, skipped,
+	      sparse_block_size_to_storage(sparse_header->total_blks,
+					   storage, sparse_header));
+	printf("........ wrote %d blocks to '%s'\n", total_blocks,
+	       storage->name);
 
-	if (total_blocks != sparse_header->total_blks) {
+	if ((total_blocks + skipped) !=
+	    sparse_block_size_to_storage(sparse_header->total_blks,
+					 storage, sparse_header)) {
 		printf("sparse image write failure\n");
 		return -EIO;
 	}
diff --git a/common/fb_mmc.c b/common/fb_mmc.c
index b31a9fb..c9f2ed6 100644
--- a/common/fb_mmc.c
+++ b/common/fb_mmc.c
@@ -6,6 +6,7 @@
 
 #include <config.h>
 #include <common.h>
+#include <errno.h>
 #include <fastboot.h>
 #include <fb_mmc.h>
 #include <part.h>
@@ -19,6 +20,10 @@
 
 static char *response_str;
 
+struct fb_mmc_sparse {
+	block_dev_desc_t	*dev_desc;
+};
+
 static int get_partition_info_efi_by_name_or_alias(block_dev_desc_t *dev_desc,
 		const char *name, disk_partition_t *info)
 {
@@ -41,6 +46,24 @@
 	return ret;
 }
 
+
+static int fb_mmc_sparse_write(struct sparse_storage *storage,
+			       void *priv,
+			       unsigned int offset,
+			       unsigned int size,
+			       char *data)
+{
+	struct fb_mmc_sparse *sparse = priv;
+	block_dev_desc_t *dev_desc = sparse->dev_desc;
+	int ret;
+
+	ret = dev_desc->block_write(dev_desc->dev, offset, size, data);
+	if (!ret)
+		return -EIO;
+
+	return ret;
+}
+
 static void write_raw_image(block_dev_desc_t *dev_desc, disk_partition_t *info,
 		const char *part_name, void *buffer,
 		unsigned int download_bytes)
@@ -113,12 +136,26 @@
 		return;
 	}
 
-	if (is_sparse_image(download_buffer))
-		write_sparse_image(dev_desc, &info, cmd, download_buffer,
-				   download_bytes);
-	else
+	if (is_sparse_image(download_buffer)) {
+		struct fb_mmc_sparse sparse_priv;
+		sparse_storage_t sparse;
+
+		sparse_priv.dev_desc = dev_desc;
+
+		sparse.block_sz = info.blksz;
+		sparse.start = info.start;
+		sparse.size = info.size;
+		sparse.name = cmd;
+		sparse.write = fb_mmc_sparse_write;
+
+		printf("Flashing sparse image at offset " LBAFU "\n",
+		       info.start);
+
+		store_sparse_image(&sparse, &sparse_priv, download_buffer);
+	} else {
 		write_raw_image(dev_desc, &info, cmd, download_buffer,
 				download_bytes);
+	}
 
 	fastboot_okay(response_str, "");
 }