1 files changed, 321 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos/subsystem_restart.c b/arch/arm/mach-exynos/subsystem_restart.c
new file mode 100644
index 0000000..a68804f
--- /dev/null
+++ b/arch/arm/mach-exynos/subsystem_restart.c
@@ -0,0 +1,321 @@
+/* Copyright (c) 2011-2012, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) "subsys-restart: %s(): " fmt, __func__
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/list.h>
+#include <linux/io.h>
+#include <linux/time.h>
+#include <linux/wakelock.h>
+#include <linux/suspend.h>
+#include <mach/subsystem_restart.h>
+
+struct subsys_soc_restart_order {
+	const char * const *subsystem_list;
+	int count;
+
+	struct mutex shutdown_lock;
+	struct mutex powerup_lock;
+	struct subsys_data *subsys_ptrs[];
+};
+
+struct restart_wq_data {
+	struct subsys_data *subsys;
+	struct wake_lock ssr_wake_lock;
+	char wakelockname[64];
+	int coupled;
+	struct work_struct work;
+};
+
+struct restart_log {
+	struct timeval time;
+	struct subsys_data *subsys;
+	struct list_head list;
+};
+
+static int restart_level;
+static int mdm_dump = 1;
+struct workqueue_struct *ssr_wq;
+
+static LIST_HEAD(restart_log_list);
+static LIST_HEAD(subsystem_list);
+static DEFINE_MUTEX(subsystem_list_lock);
+static DEFINE_MUTEX(soc_order_reg_lock);
+static DEFINE_MUTEX(restart_log_mutex);
+
+/* These will be assigned to one of the sets above after
+ * runtime SoC identification.
+ */
+module_param(mdm_dump, int, S_IRUGO | S_IWUSR);
+
+static struct subsys_data *_find_subsystem(const char *subsys_name)
+{
+	struct subsys_data *subsys;
+
+	mutex_lock(&subsystem_list_lock);
+	list_for_each_entry(subsys, &subsystem_list, list)
+		if (!strncmp(subsys->name, subsys_name,
+				SUBSYS_NAME_MAX_LENGTH)) {
+			mutex_unlock(&subsystem_list_lock);
+			return subsys;
+		}
+	mutex_unlock(&subsystem_list_lock);
+
+	return NULL;
+}
+
+static int max_restarts;
+module_param(max_restarts, int, 0644);
+
+static long max_history_time = 3600;
+module_param(max_history_time, long, 0644);
+
+static void subsystem_restart_wq_func(struct work_struct *work)
+{
+	struct restart_wq_data *r_work = container_of(work,
+						struct restart_wq_data, work);
+	struct subsys_data **restart_list;
+	struct subsys_data *subsys = r_work->subsys;
+
+	struct mutex *powerup_lock;
+	struct mutex *shutdown_lock;
+
+	int i;
+	int restart_list_count = 0;
+
+	/* It's OK to not take the registration lock at this point.
+	 * This is because the subsystem list inside the relevant
+	 * restart order is not being traversed.
+	 */
+	restart_list = subsys->single_restart_list;
+	restart_list_count = 1;
+	powerup_lock = &subsys->powerup_lock;
+	shutdown_lock = &subsys->shutdown_lock;
+	pr_info("subsys[%p], powerup lock[%p], shutdown_lock[%p]\n", subsys,
+						powerup_lock, shutdown_lock);
+
+	pr_info("[%p]: Attempting to get shutdown lock!\n", current);
+
+	/* Try to acquire shutdown_lock. If this fails, these subsystems are
+	 * already being restarted - return.
+	 */
+	if (!mutex_trylock(shutdown_lock))
+		goto out;
+
+	pr_info("[%p]: Attempting to get powerup lock!\n", current);
+
+	/* Now that we've acquired the shutdown lock, either we're the first to
+	 * restart these subsystems or some other thread is doing the powerup
+	 * sequence for these subsystems. In the latter case, panic and bail
+	 * out, since a subsystem died in its powerup sequence.
+	 */
+	if (!mutex_trylock(powerup_lock))
+		panic("%s[%p]: Subsystem died during powerup!",
+						__func__, current);
+
+	/* Now it is necessary to take the registration lock. This is because
+	 * the subsystem list in the SoC restart order will be traversed
+	 * and it shouldn't be changed until _this_ restart sequence completes.
+	 */
+	mutex_lock(&soc_order_reg_lock);
+
+	pr_info("[%p]: Starting restart sequence for %s\n", current,
+			r_work->subsys->name);
+
+	for (i = 0; i < restart_list_count; i++) {
+
+		if (!restart_list[i])
+			continue;
+
+		pr_info("[%p]: Shutting down %s\n", current,
+			restart_list[i]->name);
+
+		if (restart_list[i]->shutdown(subsys) < 0)
+			panic("subsys-restart: %s[%p]: Failed to shutdown %s!",
+				__func__, current, restart_list[i]->name);
+	}
+
+	/* Now that we've finished shutting down these subsystems, release the
+	 * shutdown lock. If a subsystem restart request comes in for a
+	 * subsystem in _this_ restart order after the unlock below, and
+	 * before the powerup lock is released, panic and bail out.
+	 */
+	mutex_unlock(shutdown_lock);
+
+	/* Collect ram dumps for all subsystems in order here */
+	for (i = 0; i < restart_list_count; i++) {
+		if (!restart_list[i])
+			continue;
+
+		if (restart_list[i]->ramdump)
+			if (restart_list[i]->ramdump(mdm_dump, subsys) < 0)
+				pr_warn("%s[%p]: Ramdump failed.\n",
+						restart_list[i]->name, current);
+	}
+
+	for (i = restart_list_count - 1; i >= 0; i--) {
+
+		if (!restart_list[i])
+			continue;
+
+		pr_info("[%p]: Powering up %s\n", current,
+					restart_list[i]->name);
+
+		if (restart_list[i]->powerup(subsys) < 0)
+			panic("%s[%p]: Failed to powerup %s!", __func__,
+				current, restart_list[i]->name);
+	}
+
+	pr_info("[%p]: Restart sequence for %s completed.\n",
+			current, r_work->subsys->name);
+
+	mutex_unlock(powerup_lock);
+
+	mutex_unlock(&soc_order_reg_lock);
+
+	pr_info("[%p]: Released powerup lock!\n", current);
+
+out:
+	wake_unlock(&r_work->ssr_wake_lock);
+	wake_lock_destroy(&r_work->ssr_wake_lock);
+	kfree(r_work);
+	subsys->ongoing = false;
+}
+
+int subsystem_restart(const char *subsys_name)
+{
+	struct subsys_data *subsys;
+	struct restart_wq_data *data = NULL;
+	int rc;
+
+	if (!subsys_name) {
+		pr_err("Invalid subsystem name.\n");
+		return -EINVAL;
+	}
+
+	pr_info("Restart sequence requested for %s, restart_level = %d.\n",
+		subsys_name, restart_level);
+
+	/* List of subsystems is protected by a lock. New subsystems can
+	 * still come in.
+	 */
+	subsys = _find_subsystem(subsys_name);
+
+	if (!subsys) {
+		pr_warn("Unregistered subsystem %s!\n", subsys_name);
+		return -EINVAL;
+	}
+
+	if (subsys->ongoing) {
+		pr_warn("subsys-restart: already requested, return busy\n");
+		return -EBUSY;
+	}
+
+	subsys->ongoing = true;
+
+	data = kzalloc(sizeof(struct restart_wq_data), GFP_KERNEL);
+	if (!data) {
+		pr_warn("Failed to alloc restart data. Resetting.\n");
+		panic("subsys-restart: Resetting the SoC - %s crashed.",
+								subsys->name);
+	} else {
+		data->coupled = 0;
+		data->subsys = subsys;
+	}
+	pr_debug("Restarting %s [level=%d]!\n", subsys_name, restart_level);
+
+	snprintf(data->wakelockname, sizeof(data->wakelockname),
+						"ssr(%s)", subsys_name);
+	wake_lock_init(&data->ssr_wake_lock, WAKE_LOCK_SUSPEND,
+							data->wakelockname);
+	wake_lock(&data->ssr_wake_lock);
+
+	INIT_WORK(&data->work, subsystem_restart_wq_func);
+	rc = schedule_work(&data->work);
+	if (rc < 0)
+		panic("%s: Unable to schedule work to restart %s",
+						     __func__, subsys->name);
+	return 0;
+}
+EXPORT_SYMBOL(subsystem_restart);
+
+int ssr_register_subsystem(struct subsys_data *subsys)
+{
+	pr_info("%s\n", __func__);
+	if (!subsys)
+		goto err;
+
+	if (!subsys->name)
+		goto err;
+
+	if (!subsys->powerup || !subsys->shutdown)
+		goto err;
+
+	subsys->single_restart_list[0] = subsys;
+
+	mutex_init(&subsys->shutdown_lock);
+	mutex_init(&subsys->powerup_lock);
+
+	mutex_lock(&subsystem_list_lock);
+	list_add(&subsys->list, &subsystem_list);
+	mutex_unlock(&subsystem_list_lock);
+
+	return 0;
+
+err:
+	return -EINVAL;
+}
+EXPORT_SYMBOL(ssr_register_subsystem);
+
+static int ssr_panic_handler(struct notifier_block *this,
+				unsigned long event, void *ptr)
+{
+	struct subsys_data *subsys;
+
+	list_for_each_entry(subsys, &subsystem_list, list)
+		if (subsys->crash_shutdown)
+			subsys->crash_shutdown(subsys);
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block panic_nb = {
+	.notifier_call  = ssr_panic_handler,
+};
+
+static int __init subsys_restart_init(void)
+{
+	int ret = 0;
+
+	pr_info("%s\n", __func__);
+
+	restart_level = RESET_SOC;
+
+	ssr_wq = alloc_workqueue("ssr_wq", 0, 0);
+
+	if (!ssr_wq)
+		panic("Couldn't allocate workqueue for subsystem restart.\n");
+
+	atomic_notifier_chain_register(&panic_notifier_list,
+			&panic_nb);
+
+	return ret;
+}
+
+arch_initcall(subsys_restart_init);
+
+MODULE_DESCRIPTION("Subsystem Restart Driver");
+MODULE_LICENSE("GPL v2");