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authorRafael J. Wysocki <rjw@sisk.pl>2011-03-15 00:43:46 +0100
committerRafael J. Wysocki <rjw@sisk.pl>2011-03-15 00:43:46 +0100
commit40dc166cb5dddbd36aa4ad11c03915ea538f5a61 (patch)
tree0a778159cf89ddee9e7d3134ae40569bdccd2a24 /drivers/base/syscore.c
parentf9b9e806ae0ede772cbb9916d9ac7354a123d044 (diff)
PM / Core: Introduce struct syscore_ops for core subsystems PM
Some subsystems need to carry out suspend/resume and shutdown operations with one CPU on-line and interrupts disabled. The only way to register such operations is to define a sysdev class and a sysdev specifically for this purpose which is cumbersome and inefficient. Moreover, the arguments taken by sysdev suspend, resume and shutdown callbacks are practically never necessary. For this reason, introduce a simpler interface allowing subsystems to register operations to be executed very late during system suspend and shutdown and very early during resume in the form of strcut syscore_ops objects. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/base/syscore.c')
-rw-r--r--drivers/base/syscore.c117
1 files changed, 117 insertions, 0 deletions
diff --git a/drivers/base/syscore.c b/drivers/base/syscore.c
new file mode 100644
index 000000000000..90af2943f9e4
--- /dev/null
+++ b/drivers/base/syscore.c
@@ -0,0 +1,117 @@
+/*
+ * syscore.c - Execution of system core operations.
+ *
+ * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/syscore_ops.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+
+static LIST_HEAD(syscore_ops_list);
+static DEFINE_MUTEX(syscore_ops_lock);
+
+/**
+ * register_syscore_ops - Register a set of system core operations.
+ * @ops: System core operations to register.
+ */
+void register_syscore_ops(struct syscore_ops *ops)
+{
+ mutex_lock(&syscore_ops_lock);
+ list_add_tail(&ops->node, &syscore_ops_list);
+ mutex_unlock(&syscore_ops_lock);
+}
+EXPORT_SYMBOL_GPL(register_syscore_ops);
+
+/**
+ * unregister_syscore_ops - Unregister a set of system core operations.
+ * @ops: System core operations to unregister.
+ */
+void unregister_syscore_ops(struct syscore_ops *ops)
+{
+ mutex_lock(&syscore_ops_lock);
+ list_del(&ops->node);
+ mutex_unlock(&syscore_ops_lock);
+}
+EXPORT_SYMBOL_GPL(unregister_syscore_ops);
+
+#ifdef CONFIG_PM_SLEEP
+/**
+ * syscore_suspend - Execute all the registered system core suspend callbacks.
+ *
+ * This function is executed with one CPU on-line and disabled interrupts.
+ */
+int syscore_suspend(void)
+{
+ struct syscore_ops *ops;
+ int ret = 0;
+
+ WARN_ONCE(!irqs_disabled(),
+ "Interrupts enabled before system core suspend.\n");
+
+ list_for_each_entry_reverse(ops, &syscore_ops_list, node)
+ if (ops->suspend) {
+ if (initcall_debug)
+ pr_info("PM: Calling %pF\n", ops->suspend);
+ ret = ops->suspend();
+ if (ret)
+ goto err_out;
+ WARN_ONCE(!irqs_disabled(),
+ "Interrupts enabled after %pF\n", ops->suspend);
+ }
+
+ return 0;
+
+ err_out:
+ pr_err("PM: System core suspend callback %pF failed.\n", ops->suspend);
+
+ list_for_each_entry_continue(ops, &syscore_ops_list, node)
+ if (ops->resume)
+ ops->resume();
+
+ return ret;
+}
+
+/**
+ * syscore_resume - Execute all the registered system core resume callbacks.
+ *
+ * This function is executed with one CPU on-line and disabled interrupts.
+ */
+void syscore_resume(void)
+{
+ struct syscore_ops *ops;
+
+ WARN_ONCE(!irqs_disabled(),
+ "Interrupts enabled before system core resume.\n");
+
+ list_for_each_entry(ops, &syscore_ops_list, node)
+ if (ops->resume) {
+ if (initcall_debug)
+ pr_info("PM: Calling %pF\n", ops->resume);
+ ops->resume();
+ WARN_ONCE(!irqs_disabled(),
+ "Interrupts enabled after %pF\n", ops->resume);
+ }
+}
+#endif /* CONFIG_PM_SLEEP */
+
+/**
+ * syscore_shutdown - Execute all the registered system core shutdown callbacks.
+ */
+void syscore_shutdown(void)
+{
+ struct syscore_ops *ops;
+
+ mutex_lock(&syscore_ops_lock);
+
+ list_for_each_entry_reverse(ops, &syscore_ops_list, node)
+ if (ops->shutdown) {
+ if (initcall_debug)
+ pr_info("PM: Calling %pF\n", ops->shutdown);
+ ops->shutdown();
+ }
+
+ mutex_unlock(&syscore_ops_lock);
+}