[PATCH v24 01/12] power: reset: reboot-mode: Support up to 3 magic values per mode

[Shivendra Pratap]

ARM PSCI vendor-specific resets, require a 32-bit reset_type and a 64-bit
cookie as arguments. This cannot be implemented via the reboot-mode
framework, which supports a single 32-bit argument as magic value.

Extend the reboot-mode framework to support up to three 32-bit arguments
as magic, per reboot-mode.

Signed-off-by: Shivendra Pratap <shivendra.pratap at oss.qualcomm.com>
---
 drivers/power/reset/reboot-mode.c | 46 +++++++++++++++++++++++++++------------
 include/linux/reboot-mode.h       |  3 +++
 2 files changed, 35 insertions(+), 14 deletions(-)

diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
index af00c00eceee..c7e9285c64e9 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -20,7 +20,8 @@
 
 struct mode_info {
 	const char *mode;
-	u32 magic;
+	u32 magic[3];
+	u32 count;
 	struct list_head list;
 };
 
@@ -72,8 +73,7 @@ static const struct class reboot_mode_class = {
 	.dev_groups = reboot_mode_groups,
 };
 
-static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
-					  const char *cmd)
+static struct mode_info *get_reboot_mode_info(struct reboot_mode_driver *reboot, const char *cmd)
 {
 	const char *normal = "normal";
 	struct mode_info *info;
@@ -84,11 +84,11 @@ static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
 
 	list_for_each_entry(info, &reboot->head, list)
 		if (!strcmp(info->mode, cmd))
-			return info->magic;
+			return info;
 
 	/* try to match again, replacing characters impossible in DT */
 	if (strscpy(cmd_, cmd, sizeof(cmd_)) == -E2BIG)
-		return 0;
+		return NULL;
 
 	strreplace(cmd_, ' ', '-');
 	strreplace(cmd_, ',', '-');
@@ -96,21 +96,25 @@ static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
 
 	list_for_each_entry(info, &reboot->head, list)
 		if (!strcmp(info->mode, cmd_))
-			return info->magic;
+			return info;
 
-	return 0;
+	return NULL;
 }
 
 static int reboot_mode_notify(struct notifier_block *this,
 			      unsigned long mode, void *cmd)
 {
 	struct reboot_mode_driver *reboot;
-	unsigned int magic;
+	struct mode_info *info;
 
 	reboot = container_of(this, struct reboot_mode_driver, reboot_notifier);
-	magic = get_reboot_mode_magic(reboot, cmd);
-	if (magic)
-		reboot->write(reboot, magic);
+	info = get_reboot_mode_info(reboot, cmd);
+	if (info && info->count) {
+		if (reboot->write_array)
+			reboot->write_array(reboot, info->magic, info->count);
+		else if (reboot->write && info->magic[0])
+			reboot->write(reboot, info->magic[0]);
+	}
 
 	return NOTIFY_DONE;
 }
@@ -173,16 +177,22 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
 	struct property *prop;
 	struct device_node *np = reboot->dev->of_node;
 	size_t len = strlen(PREFIX);
-	u32 magic;
+	u32 magic[3];
+	int count;
 	int ret;
 
 	INIT_LIST_HEAD(&reboot->head);
 
 	for_each_property_of_node(np, prop) {
+		memset(magic, 0, sizeof(magic));
+
 		if (strncmp(prop->name, PREFIX, len))
 			continue;
 
-		if (device_property_read_u32(reboot->dev, prop->name, &magic)) {
+		count = device_property_count_u32(reboot->dev, prop->name);
+
+		if (count <= 0 || count > ARRAY_SIZE(magic) ||
+		    device_property_read_u32_array(reboot->dev, prop->name, magic, count)) {
 			dev_dbg(reboot->dev, "reboot mode %s without magic number\n",
 				prop->name);
 			continue;
@@ -194,7 +204,15 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
 			goto error;
 		}
 
-		info->magic = magic;
+		if (!memchr_inv(magic, 0, count * sizeof(u32))) {
+			dev_dbg(reboot->dev, "reboot mode %s with zero magic values\n",
+				prop->name);
+			info->count = 0;
+		} else {
+			memcpy(info->magic, magic, count * sizeof(u32));
+			info->count = count;
+		}
+
 		info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
 		if (!info->mode) {
 			ret = -ENOMEM;
diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
index 4a2abb38d1d6..29ae39935d69 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -2,10 +2,13 @@
 #ifndef __REBOOT_MODE_H__
 #define __REBOOT_MODE_H__
 
+#include <linux/types.h>
+
 struct reboot_mode_driver {
 	struct device *dev;
 	struct list_head head;
 	int (*write)(struct reboot_mode_driver *reboot, unsigned int magic);
+	int (*write_array)(struct reboot_mode_driver *reboot, const u32 *magic, int count);
 	struct notifier_block reboot_notifier;
 };
 

-- 
2.34.1