bootstd: Move the bootflow list into an alist

Use an alist for this data structure as it is somewhat simpler to
manage. This means that bootstd holds a simple list of bootflow structs
and can drop it at will, without chasing down lists.

Signed-off-by: Simon Glass <sjg@chromium.org>

boot/bootdev-uclass.c

@@ -32,41 +32,17 @@ enum {
 	BOOT_TARGETS_MAX_LEN	= 100,
 };
 
-struct bootflow *bootdev_next_bootflow_(struct bootstd_priv *std,
-					struct udevice *dev,
-					struct bootflow *prev)
-{
-	struct bootflow *bflow = prev;
-
-	if (bflow) {
-		if (list_is_last(&bflow->glob_node, &std->glob_head))
-			return NULL;
-		bflow = list_entry(bflow->glob_node.next, struct bootflow,
-				   glob_node);
-	} else {
-		if (list_empty(&std->glob_head))
-			return NULL;
-
-		bflow = list_first_entry(&std->glob_head, struct bootflow,
-					 glob_node);
-	}
-
-	while (bflow->dev != dev) {
-		if (list_is_last(&bflow->glob_node, &std->glob_head))
-			return NULL;
-		bflow = list_entry(bflow->glob_node.next, struct bootflow,
-				   glob_node);
-	}
-
-	return bflow;
-}
-
 int bootdev_first_bootflow(struct udevice *dev, struct bootflow **bflowp)
 {
-	struct bootstd_priv *std = bootstd_try_priv();
+	struct bootstd_priv *std;
 	struct bootflow *bflow;
+	int ret;
 
-	bflow = bootdev_next_bootflow_(std, dev, NULL);
+	ret = bootstd_get_priv(&std);
+	if (ret)
+		return log_msg_ret("bff", ret);
+
+	bflow = alist_getw(&std->bootflows, 0, struct bootflow);
 	if (!bflow)
 		return -ENOENT;
 	*bflowp = bflow;
@@ -76,10 +52,15 @@ int bootdev_first_bootflow(struct udevice *dev, struct bootflow **bflowp)
 
 int bootdev_next_bootflow(struct bootflow **bflowp)
 {
-	struct bootstd_priv *std = bootstd_try_priv();
+	struct bootstd_priv *std;
 	struct bootflow *bflow;
+	int ret;
 
-	bflow = bootdev_next_bootflow_(std, (*bflowp)->dev, *bflowp);
+	ret = bootstd_get_priv(&std);
+	if (ret)
+		return log_msg_ret("bff", ret);
+
+	bflow = alist_nextw(&std->bootflows, *bflowp);
 	if (!bflow)
 		return -ENOENT;
 	*bflowp = bflow;

boot/bootflow.c

@@ -55,11 +55,10 @@ int bootflow_first_glob(struct bootflow **bflowp)
 	if (ret)
 		return ret;
 
-	if (list_empty(&std->glob_head))
+	if (!std->bootflows.count)
 		return -ENOENT;
 
-	*bflowp = list_first_entry(&std->glob_head, struct bootflow,
-				   glob_node);
+	*bflowp = alist_getw(&std->bootflows, 0, struct bootflow);
 
 	return 0;
 }
@@ -67,20 +66,16 @@ int bootflow_first_glob(struct bootflow **bflowp)
 int bootflow_next_glob(struct bootflow **bflowp)
 {
 	struct bootstd_priv *std;
-	struct bootflow *bflow = *bflowp;
 	int ret;
 
 	ret = bootstd_get_priv(&std);
 	if (ret)
 		return ret;
 
-	*bflowp = NULL;
-
-	if (list_is_last(&bflow->glob_node, &std->glob_head))
+	*bflowp = alist_nextw(&std->bootflows, *bflowp);
+	if (!*bflowp)
 		return -ENOENT;
 
-	*bflowp = list_entry(bflow->glob_node.next, struct bootflow, glob_node);
-
 	return 0;
 }
 
@@ -476,10 +471,7 @@ void bootflow_free(struct bootflow *bflow)
 
 void bootflow_remove(struct bootflow *bflow)
 {
-	list_del(&bflow->glob_node);
-
 	bootflow_free(bflow);
-	free(bflow);
 }
 
 #if CONFIG_IS_ENABLED(BOOTSTD_FULL)

boot/bootstd-uclass.c

@@ -6,6 +6,7 @@
  * Written by Simon Glass <sjg@chromium.org>
  */
 
+#include <alist.h>
 #include <bootflow.h>
 #include <bootstd.h>
 #include <dm.h>
@@ -42,13 +43,11 @@ static int bootstd_of_to_plat(struct udevice *dev)
 
 static void bootstd_clear_glob_(struct bootstd_priv *priv)
 {
-	while (!list_empty(&priv->glob_head)) {
-		struct bootflow *bflow;
+	struct bootflow *bflow;
 
-		bflow = list_first_entry(&priv->glob_head, struct bootflow,
-					 glob_node);
+	alist_for_each(bflow, &priv->bootflows)
 		bootflow_remove(bflow);
-	}
+	alist_empty(&priv->bootflows);
 }
 
 void bootstd_clear_glob(void)
@@ -64,36 +63,37 @@ void bootstd_clear_glob(void)
 int bootstd_add_bootflow(struct bootflow *bflow)
 {
 	struct bootstd_priv *std;
-	struct bootflow *new;
 	int ret;
 
 	ret = bootstd_get_priv(&std);
 	if (ret)
 		return ret;
 
-	new = malloc(sizeof(*bflow));
-	if (!new)
-		return log_msg_ret("bflow", -ENOMEM);
-	memcpy(new, bflow, sizeof(*bflow));
+	ret = std->bootflows.count;
+	bflow = alist_add(&std->bootflows, *bflow);
+	if (!bflow)
+		return log_msg_ret("bf2", -ENOMEM);
 
-	list_add_tail(&new->glob_node, &std->glob_head);
-
-	return 0;
+	return ret;
 }
 
 int bootstd_clear_bootflows_for_bootdev(struct udevice *dev)
 {
 	struct bootstd_priv *std = bootstd_try_priv();
+	struct bootflow *from, *to;
 
-	if (std) {
-		struct bootflow *bflow;
-		struct list_head *pos;
+	/* if bootstd does not exist we cannot have any bootflows */
+	if (!std)
+		return 0;
 
-		list_for_each(pos, &std->glob_head) {
-			bflow = list_entry(pos, struct bootflow, glob_node);
-			bootflow_remove(bflow);
-		}
+	/* Drop any bootflows that mention this dev */
+	alist_for_each_filter(from, to, &std->bootflows) {
+		if (from->dev == dev)
+			bootflow_remove(from);
+		else
+			*to++ = *from;
 	}
+	alist_update_end(&std->bootflows, to);
 
 	return 0;
 }
@@ -165,7 +165,7 @@ static int bootstd_probe(struct udevice *dev)
 {
 	struct bootstd_priv *std = dev_get_priv(dev);
 
-	INIT_LIST_HEAD(&std->glob_head);
+	alist_init_struct(&std->bootflows, struct bootflow);
 
 	return 0;
 }

cmd/bootdev.c

@@ -81,7 +81,7 @@ static int do_bootdev_info(struct cmd_tbl *cmdtp, int flag, int argc,
 
 	dev = priv->cur_bootdev;
 
-	/* Count the number of bootflows, including how many are valid*/
+	/* Count the number of bootflows, including how many are valid */
 	num_valid = 0;
 	for (ret = bootdev_first_bootflow(dev, &bflow), i = 0;
 	     !ret;

cmd/bootflow.c

@@ -208,7 +208,7 @@ static int do_bootflow_scan(struct cmd_tbl *cmdtp, int flag, int argc,
 		if (!ret)
 			num_valid++;
 		ret = bootstd_add_bootflow(&bflow);
-		if (ret) {
+		if (ret < 0) {
 			printf("Out of memory\n");
 			return CMD_RET_FAILURE;
 		}

include/bootflow.h

@@ -56,11 +56,8 @@ enum bootflow_flags_t {
 /**
  * struct bootflow - information about a bootflow
  *
- * This is connected into a linked list:
+ * All bootflows are listed in bootstd's bootflow alist in struct bootstd_priv
  *
- *   glob_sibling - links all bootflows in all bootdevs
- *
- * @glob_node: Points to siblings in the global list (all bootdev)
  * @dev: Bootdev device which produced this bootflow, NULL for flows created by
  *      BOOTMETHF_GLOBAL bootmeths
  * @blk: Block device which contains this bootflow, NULL if this is a network
@@ -90,7 +87,6 @@ enum bootflow_flags_t {
  * @bootmeth_priv: Private data for the bootmeth
  */
 struct bootflow {
-	struct list_head glob_node;
 	struct udevice *dev;
 	struct udevice *blk;
 	int part;
@@ -390,7 +386,10 @@ const char *bootflow_state_get_name(enum bootflow_state_t state);
 /**
  * bootflow_remove() - Remove a bootflow and free its memory
  *
- * This updates the linked lists containing the bootflow then frees it.
+ * This updates the 'global' linked list containing the bootflow, then frees it.
+ * It does not remove it from bootflows alist in struct bootstd_priv
+ *
+ * This does not free bflow itself, since this is assumed to be in an alist
  *
  * @bflow: Bootflow to remove
  */

include/bootstd.h

@@ -9,6 +9,7 @@
 #ifndef __bootstd_h
 #define __bootstd_h
 
+#include <alist.h>
 #include <dm/ofnode_decl.h>
 #include <linux/list.h>
 #include <linux/types.h>
@@ -30,7 +31,8 @@ struct udevice;
  *	terminated)
  * @cur_bootdev: Currently selected bootdev (for commands)
  * @cur_bootflow: Currently selected bootflow (for commands)
- * @glob_head: Head for the global list of all bootflows across all bootdevs
+ * @bootflows: (struct bootflow) Global list of all bootflows across all
+ *	bootdevs
  * @bootmeth_count: Number of bootmeth devices in @bootmeth_order
  * @bootmeth_order: List of bootmeth devices to use, in order, NULL-terminated
  * @vbe_bootmeth: Currently selected VBE bootmeth, NULL if none
@@ -44,7 +46,7 @@ struct bootstd_priv {
 	const char **env_order;
 	struct udevice *cur_bootdev;
 	struct bootflow *cur_bootflow;
-	struct list_head glob_head;
+	struct alist bootflows;
 	int bootmeth_count;
 	struct udevice **bootmeth_order;
 	struct udevice *vbe_bootmeth;
@@ -135,7 +137,7 @@ int bootstd_prog_boot(void);
  *	since this function takes over ownership of these. This functions makes
  *	a copy of @bflow itself (without allocating its fields again), so the
  *	caller must dispose of the memory used by the @bflow pointer itself
- * Return: 0 if OK, -ENOMEM if out of memory
+ * Return: element number in the list, if OK, -ENOMEM if out of memory
  */
 int bootstd_add_bootflow(struct bootflow *bflow);