Suspend and hibernation test facility (rev. 2)

Index: linux-2.6/kernel/power/main.c
===================================================================
@@ -28,6 +28,80 @@ BLOCKING_NOTIFIER_HEAD(pm_chain_head);
 
 DEFINE_MUTEX(pm_mutex);
 
+#ifdef CONFIG_PM_DEBUG
+int pm_test_level = TEST_NONE;
+
+static int suspend_test(int level)
+{
+	if (pm_test_level == level) {
+		printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
+		mdelay(5000);
+		return 1;
+	}
+	return 0;
+}
+
+static const char * const pm_tests[__TEST_AFTER_LAST] = {
+	[TEST_NONE] = "none",
+	[TEST_CORE] = "core",
+	[TEST_CPUS] = "processors",
+	[TEST_PLATFORM] = "platform",
+	[TEST_DEVICES] = "devices",
+	[TEST_FREEZER] = "freezer",
+};
+
+static ssize_t pm_test_show(struct kset *kset, char *buf)
+{
+	char *s = buf;
+	int level;
+
+	for (level = TEST_FIRST; level <= TEST_MAX; level++)
+		if (pm_tests[level]) {
+			if (level == pm_test_level)
+				s += sprintf(s, "[%s] ", pm_tests[level]);
+			else
+				s += sprintf(s, "%s ", pm_tests[level]);
+		}
+
+	if (s != buf)
+		/* convert the last space to a newline */
+		*(s-1) = '\n';
+
+	return (s - buf);
+}
+
+static ssize_t pm_test_store(struct kset *kset, const char *buf, size_t n)
+{
+	const char * const *s;
+	int level;
+	char *p;
+	int len;
+	int error = -EINVAL;
+
+	p = memchr(buf, '\n', n);
+	len = p ? p - buf : n;
+
+	mutex_lock(&pm_mutex);
+
+	level = TEST_FIRST;
+	for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
+		if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
+			pm_test_level = level;
+			error = 0;
+			break;
+		}
+
+	mutex_unlock(&pm_mutex);
+
+	return error ? error : n;
+}
+
+power_attr(pm_test);
+#else /* !CONFIG_PM_DEBUG */
+static inline int suspend_test(int level) { return 0; }
+#endif /* !CONFIG_PM_DEBUG */
+
+
 #ifdef CONFIG_SUSPEND
 
 /* This is just an arbitrary number */

@@ -133,7 +207,10 @@ static int suspend_enter(suspend_state_t
 		printk(KERN_ERR "Some devices failed to power down\n");
 		goto Done;
 	}
-	error = suspend_ops->enter(state);
+
+	if (!suspend_test(TEST_CORE))
+		error = suspend_ops->enter(state);
+
 	device_power_up();
  Done:
 	arch_suspend_enable_irqs();

@@ -164,16 +241,25 @@ int suspend_devices_and_enter(suspend_st
 		printk(KERN_ERR "Some devices failed to suspend\n");
 		goto Resume_console;
 	}
+
+	if (suspend_test(TEST_DEVICES))
+		goto Resume_devices;
+
 	if (suspend_ops->prepare) {
 		error = suspend_ops->prepare();
 		if (error)
 			goto Resume_devices;
 	}
+
+	if (suspend_test(TEST_PLATFORM))
+		goto Finish;
+
 	error = disable_nonboot_cpus();
-	if (!error)
+	if (!error && !suspend_test(TEST_CPUS))
 		suspend_enter(state);
 
 	enable_nonboot_cpus();
+ Finish:
 	if (suspend_ops->finish)
 		suspend_ops->finish();
  Resume_devices:

@@ -240,12 +326,17 @@ static int enter_state(suspend_state_t s
 	printk("done.\n");
 
 	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
-	if ((error = suspend_prepare()))
+	error = suspend_prepare();
+	if (error)
 		goto Unlock;
 
+	if (suspend_test(TEST_FREEZER))
+		goto Finish;
+
 	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
 	error = suspend_devices_and_enter(state);
 
+ Finish:
 	pr_debug("PM: Finishing wakeup.\n");
 	suspend_finish();
  Unlock:

@@ -363,18 +454,18 @@ pm_trace_store(struct kset *kset, const 
 }
 
 power_attr(pm_trace);
+#endif /* CONFIG_PM_TRACE */
 
 static struct attribute * g[] = {
 	&state_attr.attr,
+#ifdef CONFIG_PM_TRACE
 	&pm_trace_attr.attr,
+#endif
+#ifdef CONFIG_PM_DEBUG
+	&pm_test_attr.attr,
+#endif
 	NULL,
 };
-#else
-static struct attribute * g[] = {
-	&state_attr.attr,
-	NULL,
-};
-#endif /* CONFIG_PM_TRACE */
 
 static struct attribute_group attr_group = {
 	.attrs = g,

Index: linux-2.6/kernel/power/power.h
===================================================================
@@ -190,3 +190,21 @@ int restore_highmem(void);
 static inline unsigned int count_highmem_pages(void) { return 0; }
 static inline int restore_highmem(void) { return 0; }
 #endif
+
+/*
+ * Suspend test levels
+ */
+enum {
+	/* keep first */
+	TEST_NONE,
+	TEST_CORE,
+	TEST_CPUS,
+	TEST_PLATFORM,
+	TEST_DEVICES,
+	TEST_FREEZER,
+	/* keep last */
+	__TEST_AFTER_LAST
+};
+
+#define TEST_FIRST	TEST_NONE
+#define TEST_MAX	(__TEST_AFTER_LAST - 1)

Index: linux-2.6/kernel/power/disk.c
===================================================================
@@ -70,6 +70,35 @@ void hibernation_set_ops(struct platform
 	mutex_unlock(&pm_mutex);
 }
 
+#ifdef CONFIG_PM_DEBUG
+static void hibernation_debug_sleep(void)
+{
+	printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
+	mdelay(5000);
+}
+
+static int hibernation_testmode(int mode)
+{
+	if (hibernation_mode == mode) {
+		hibernation_debug_sleep();
+		return 1;
+	}
+	return 0;
+}
+
+static int hibernation_test(int level)
+{
+	if (pm_test_level == level) {
+		hibernation_debug_sleep();
+		return 1;
+	}
+	return 0;
+}
+#else /* !CONFIG_PM_DEBUG */
+static int hibernation_testmode(int mode) { return 0; }
+static int hibernation_test(int level) { return 0; }
+#endif /* !CONFIG_PM_DEBUG */
+
 /**
  *	platform_start - tell the platform driver that we're starting
  *	hibernation

@@ -167,6 +196,10 @@ int create_image(int platform_mode)
 		goto Enable_irqs;
 	}
 
+	if (hibernation_test(TEST_CORE))
+		goto Power_up;
+
+	in_suspend = 1;
 	save_processor_state();
 	error = swsusp_arch_suspend();
 	if (error)

@@ -175,6 +208,7 @@ int create_image(int platform_mode)
 	restore_processor_state();
 	if (!in_suspend)
 		platform_leave(platform_mode);
+ Power_up:
 	/* NOTE:  device_power_up() is just a resume() for devices
 	 * that suspended with irqs off ... no overall powerup.
 	 */

@@ -211,24 +245,29 @@ int hibernation_snapshot(int platform_mo
 	if (error)
 		goto Resume_console;
 
-	error = platform_pre_snapshot(platform_mode);
-	if (error)
+	if (hibernation_test(TEST_DEVICES))
 		goto Resume_devices;
 
+	error = platform_pre_snapshot(platform_mode);
+	if (error || hibernation_test(TEST_PLATFORM))
+		goto Finish;
+
 	error = disable_nonboot_cpus();
 	if (!error) {
-		if (hibernation_mode != HIBERNATION_TEST) {
-			in_suspend = 1;
-			error = create_image(platform_mode);
-			/* Control returns here after successful restore */
-		} else {
-			printk("swsusp debug: Waiting for 5 seconds.\n");
-			mdelay(5000);
-		}
+		if (hibernation_test(TEST_CPUS))
+			goto Enable_cpus;
+
+		if (hibernation_testmode(HIBERNATION_TEST))
+			goto Enable_cpus;
+
+		error = create_image(platform_mode);
+		/* Control returns here after successful restore */
 	}
+ Enable_cpus:
 	enable_nonboot_cpus();
- Resume_devices:
+ Finish:
 	platform_finish(platform_mode);
+ Resume_devices:
 	device_resume();
  Resume_console:
 	resume_console();

@@ -406,11 +445,12 @@ int hibernate(void)
 	if (error)
 		goto Finish;
 
-	if (hibernation_mode == HIBERNATION_TESTPROC) {
-		printk("swsusp debug: Waiting for 5 seconds.\n");
-		mdelay(5000);
+	if (hibernation_test(TEST_FREEZER))
 		goto Thaw;
-	}
+
+	if (hibernation_testmode(HIBERNATION_TESTPROC))
+		goto Thaw;
+
 	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 	if (in_suspend && !error) {
 		unsigned int flags = 0;

Index: linux-2.6/kernel/power/power.h
===================================================================
@@ -208,3 +208,5 @@ enum {
 
 #define TEST_FIRST	TEST_NONE
 #define TEST_MAX	(__TEST_AFTER_LAST - 1)
+
+extern int pm_test_level;