[PATCH v6 2/7] fwu: gpt: use cached meta-data partition numbers

[jassisinghbrar at gmail.com]

From: Jassi Brar <jaswinder.singh at linaro.org>

Use cached values and avoid parsing and scanning through partitions
everytime for meta-data partitions because they can't change after bootup.

Acked-by: Etienne Carriere <etienne.carriere at linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh at linaro.org>
---
 drivers/fwu-mdata/gpt_blk.c | 43 +++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/drivers/fwu-mdata/gpt_blk.c b/drivers/fwu-mdata/gpt_blk.c
index d35ce49c5c..28f5d23e1e 100644
--- a/drivers/fwu-mdata/gpt_blk.c
+++ b/drivers/fwu-mdata/gpt_blk.c
@@ -24,8 +24,9 @@ enum {
 	MDATA_WRITE,
 };
 
-static int gpt_get_mdata_partitions(struct blk_desc *desc,
-				    uint mdata_parts[2])
+static uint g_mdata_part[2]; /* = {0, 0} to check against uninit parts */
+
+static int gpt_get_mdata_partitions(struct blk_desc *desc)
 {
 	int i, ret;
 	u32 nparts;
@@ -33,18 +34,19 @@ static int gpt_get_mdata_partitions(struct blk_desc *desc,
 	struct disk_partition info;
 	const efi_guid_t fwu_mdata_guid = FWU_MDATA_GUID;
 
+	/* if primary and secondary partitions already found */
+	if (g_mdata_part[0] && g_mdata_part[1])
+		return 0;
+
 	nparts = 0;
-	for (i = 1; i < MAX_SEARCH_PARTITIONS; i++) {
+	for (i = 1; i < MAX_SEARCH_PARTITIONS && nparts < 2; i++) {
 		if (part_get_info(desc, i, &info))
 			continue;
 		uuid_str_to_bin(info.type_guid, part_type_guid.b,
 				UUID_STR_FORMAT_GUID);
 
-		if (!guidcmp(&fwu_mdata_guid, &part_type_guid)) {
-			if (nparts < 2)
-				mdata_parts[nparts] = i;
-			++nparts;
-		}
+		if (!guidcmp(&fwu_mdata_guid, &part_type_guid))
+			g_mdata_part[nparts++] = i;
 	}
 
 	if (nparts != 2) {
@@ -127,26 +129,25 @@ static int fwu_gpt_update_mdata(struct udevice *dev, struct fwu_mdata *mdata)
 {
 	int ret;
 	struct blk_desc *desc;
-	uint mdata_parts[2];
 	struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
 
 	desc = dev_get_uclass_plat(priv->blk_dev);
 
-	ret = gpt_get_mdata_partitions(desc, mdata_parts);
+	ret = gpt_get_mdata_partitions(desc);
 	if (ret < 0) {
 		log_debug("Error getting the FWU metadata partitions\n");
 		return -ENOENT;
 	}
 
 	/* First write the primary partition */
-	ret = gpt_read_write_mdata(desc, mdata, MDATA_WRITE, mdata_parts[0]);
+	ret = gpt_read_write_mdata(desc, mdata, MDATA_WRITE, g_mdata_part[0]);
 	if (ret < 0) {
 		log_debug("Updating primary FWU metadata partition failed\n");
 		return ret;
 	}
 
 	/* And now the replica */
-	ret = gpt_read_write_mdata(desc, mdata, MDATA_WRITE, mdata_parts[1]);
+	ret = gpt_read_write_mdata(desc, mdata, MDATA_WRITE, g_mdata_part[1]);
 	if (ret < 0) {
 		log_debug("Updating secondary FWU metadata partition failed\n");
 		return ret;
@@ -158,16 +159,14 @@ static int fwu_gpt_update_mdata(struct udevice *dev, struct fwu_mdata *mdata)
 static int gpt_get_mdata(struct blk_desc *desc, struct fwu_mdata *mdata)
 {
 	int ret;
-	uint mdata_parts[2];
-
-	ret = gpt_get_mdata_partitions(desc, mdata_parts);
 
+	ret = gpt_get_mdata_partitions(desc);
 	if (ret < 0) {
 		log_debug("Error getting the FWU metadata partitions\n");
 		return -ENOENT;
 	}
 
-	ret = gpt_read_write_mdata(desc, mdata, MDATA_READ, mdata_parts[0]);
+	ret = gpt_read_write_mdata(desc, mdata, MDATA_READ, g_mdata_part[0]);
 	if (ret < 0) {
 		log_debug("Failed to read the FWU metadata from the device\n");
 		return -EIO;
@@ -182,7 +181,7 @@ static int gpt_get_mdata(struct blk_desc *desc, struct fwu_mdata *mdata)
 	 * Try to read the replica.
 	 */
 	memset(mdata, '\0', sizeof(struct fwu_mdata));
-	ret = gpt_read_write_mdata(desc, mdata, MDATA_READ, mdata_parts[1]);
+	ret = gpt_read_write_mdata(desc, mdata, MDATA_READ, g_mdata_part[1]);
 	if (ret < 0) {
 		log_debug("Failed to read the FWU metadata from the device\n");
 		return -EIO;
@@ -206,9 +205,15 @@ static int fwu_gpt_get_mdata(struct udevice *dev, struct fwu_mdata *mdata)
 static int fwu_gpt_get_mdata_partitions(struct udevice *dev, uint *mdata_parts)
 {
 	struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
+	int err;
+
+	err = gpt_get_mdata_partitions(dev_get_uclass_plat(priv->blk_dev));
+	if (!err) {
+		mdata_parts[0] = g_mdata_part[0];
+		mdata_parts[1] = g_mdata_part[1];
+	}
 
-	return gpt_get_mdata_partitions(dev_get_uclass_plat(priv->blk_dev),
-					mdata_parts);
+	return err;
 }
 
 static int fwu_gpt_read_mdata_partition(struct udevice *dev,
-- 
2.34.1