[M] Change in flashrom[master]: linux_mtd.c: Split linux_mtd_init() into sub-functions

[Edward O'Callaghan (Code Review)]

Attention is currently required from: Nikolai Artemiev.

Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/73494 )

Change subject: linux_mtd.c: Split linux_mtd_init() into sub-functions
......................................................................

linux_mtd.c: Split linux_mtd_init() into sub-functions

Here we split up the linux_mtd_init() entry-point into its
constituent phases;
  get_params -> check_sysfs_path ->
  alloc resources -> setup drv -> register.

The motivation is that we wish for linux_mtd to have a pre_init
hook for the purposes of detection only. This is a requirement
for the internal programmer via the current try_mtd() hack.

Change-Id: Ic81068adbc7da8b28de07a161b5cec2fff0fce49
Signed-off-by: Edward O'Callaghan 
---
M linux_mtd.c
1 file changed, 56 insertions(+), 26 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/94/73494/1

diff --git a/linux_mtd.c b/linux_mtd.c
index 495db9a..b3be72a 100644
--- a/linux_mtd.c
+++ b/linux_mtd.c
@@ -494,26 +494,30 @@
    return ret;
 }

-static int linux_mtd_init(const struct programmer_cfg *cfg)
+static int get_params(const struct programmer_cfg *cfg, int *dev_num)
 {
-	char *param_str;
-	int dev_num = 0;
-	int ret = 1;
-	struct linux_mtd_data *data = NULL;
-
-	param_str = extract_programmer_param_str(cfg, "dev");
-	if (param_str) {
-		char *endptr;
-
-		dev_num = strtol(param_str, &endptr, 0);
-		if ((*endptr != '\0') || (dev_num < 0)) {
-			msg_perr("Invalid device number %s. Use flashrom -p "
-				"linux_mtd:dev=N where N is a valid MTD\n"
-				"device number.\n", param_str);
-			goto linux_mtd_init_exit;
-		}
+	char *param_str = extract_programmer_param_str(cfg, "dev");
+	if (!param_str) {
+		*dev_num = 0;
+		return 0;
    }

+	char *endptr;
+	*dev_num = strtol(param_str, &endptr, 0);
+	if ((*endptr != '\0') || (*dev_num < 0)) {
+		msg_perr("Invalid device number %s. Use flashrom -p "
+			"linux_mtd:dev=N where N is a valid MTD\n"
+			"device number.\n", param_str);
+		free(param_str);
+		return -1;
+	}
+
+	free(param_str);
+	return 0;
+}
+
+static int check_sysfs_devnum_path(int dev_num)
+{
    /*
     * If user specified the MTD device number then error out if it doesn't
     * appear to exist. Otherwise assume the error is benign and print a
@@ -521,19 +525,30 @@
     */
    char sysfs_path[32];
    if (snprintf(sysfs_path, sizeof(sysfs_path), "%s/mtd%d", LINUX_MTD_SYSFS_ROOT, dev_num) < 0)
-		goto linux_mtd_init_exit;
+		return -1;

struct stat s;
    if (stat(sysfs_path, &s) < 0) {
-		if (param_str)
+		if (dev_num)
    		msg_perr("%s does not exist\n", sysfs_path);
    	else
    		msg_pdbg("%s does not exist\n", sysfs_path);
-		goto linux_mtd_init_exit;
+		return -1;
    }
-	free(param_str);
+	return 0;
+}

-	data = calloc(1, sizeof(*data));
+static int linux_mtd_init(const struct programmer_cfg *cfg)
+{
+	int dev_num;
+
+	if (get_params(cfg, &dev_num) < 0)
+		return 1;
+
+	if (check_sysfs_devnum_path(dev_num) < 0)
+		return 1;
+
+	struct linux_mtd_data *data = calloc(1, sizeof(*data));
    if (!data) {
    	msg_perr("Unable to allocate memory for linux_mtd_data\n");
    	return 1;
@@ -546,10 +561,6 @@
    }

return register_opaque_master(&linux_mtd_opaque_master, data);
-
-linux_mtd_init_exit:
-	free(param_str);
-	return ret;
 }

const struct programmer_entry programmer_linux_mtd = {