ACPI: Enhance /sys/firmware/interrupts to allow enable/disable/clear from user-space

Allow users to enable/disable/clear a specific & valid GPE/Fixed Event
in user space.

This is useful for debugging, especially for some
interrupt storm issues.

All wakeup GPEs are disabled and they can not be enabled at runtime,
and we mark them as invalid.

All GPEs that don't have a _Lxx/_Exx method are marked as invalid.

All Fixed Events that don't have an event handler are marked as invalid
and they can't be enabled until an event handler is registered.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Ling Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

1 files changed, 156 insertions, 13 deletions

diff --git a/drivers/acpi/system.c b/drivers/acpi/system.c
index 5bd2dec9a7ac..d8e3f153b295 100644
--- a/drivers/acpi/system.c
+++ b/drivers/acpi/system.c
@@ -167,7 +167,13 @@ static int acpi_system_sysfs_init(void)
 #define COUNT_ERROR 2	/* other */
 #define NUM_COUNTERS_EXTRA 3
 
-static u32 *all_counters;
+#define ACPI_EVENT_VALID	0x01
+struct event_counter {
+	u32 count;
+	u32 flags;
+};
+
+static struct event_counter *all_counters;
 static u32 num_gpes;
 static u32 num_counters;
 static struct attribute **all_attrs;
@@ -202,9 +208,44 @@ static int count_num_gpes(void)
 	return count;
 }
 
+static int get_gpe_device(int index, acpi_handle *handle)
+{
+	struct acpi_gpe_xrupt_info *gpe_xrupt_info;
+	struct acpi_gpe_block_info *gpe_block;
+	acpi_cpu_flags flags;
+	struct acpi_namespace_node *node;
+
+	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
+
+	gpe_xrupt_info = acpi_gbl_gpe_xrupt_list_head;
+	while (gpe_xrupt_info) {
+		gpe_block = gpe_xrupt_info->gpe_block_list_head;
+		node = gpe_block->node;
+		while (gpe_block) {
+			index -= gpe_block->register_count *
+			    ACPI_GPE_REGISTER_WIDTH;
+			if (index < 0) {
+				acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
+				/* return NULL if it's FADT GPE */
+				if (node->type != ACPI_TYPE_DEVICE)
+					*handle = NULL;
+				else
+					*handle = node;
+				return 0;
+			}
+			node = gpe_block->node;
+			gpe_block = gpe_block->next;
+		}
+		gpe_xrupt_info = gpe_xrupt_info->next;
+	}
+	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
+
+	return -ENODEV;
+}
+
 static void delete_gpe_attr_array(void)
 {
-	u32 *tmp = all_counters;
+	struct event_counter *tmp = all_counters;
 
 	all_counters = NULL;
 	kfree(tmp);
@@ -230,9 +271,10 @@ void acpi_os_gpe_count(u32 gpe_number)
 		return;
 
 	if (gpe_number < num_gpes)
-		all_counters[gpe_number]++;
+		all_counters[gpe_number].count++;
 	else
-		all_counters[num_gpes + ACPI_NUM_FIXED_EVENTS + COUNT_ERROR]++;
+		all_counters[num_gpes + ACPI_NUM_FIXED_EVENTS + COUNT_ERROR].
+					count++;
 
 	return;
 }
@@ -243,44 +285,144 @@ void acpi_os_fixed_event_count(u32 event_number)
 		return;
 
 	if (event_number < ACPI_NUM_FIXED_EVENTS)
-		all_counters[num_gpes + event_number]++;
+		all_counters[num_gpes + event_number].count++;
 	else
-		all_counters[num_gpes + ACPI_NUM_FIXED_EVENTS + COUNT_ERROR]++;
+		all_counters[num_gpes + ACPI_NUM_FIXED_EVENTS + COUNT_ERROR].
+				count++;
 
 	return;
 }
 
+static int get_status(u32 index, acpi_event_status *status, acpi_handle *handle)
+{
+	int result = 0;
+
+	if (index >= num_gpes + ACPI_NUM_FIXED_EVENTS)
+		goto end;
+
+	if (index < num_gpes) {
+		result = get_gpe_device(index, handle);
+		if (result) {
+			ACPI_EXCEPTION((AE_INFO, AE_NOT_FOUND,
+				"Invalid GPE 0x%x\n", index));
+			goto end;
+		}
+		result = acpi_get_gpe_status(*handle, index,
+						ACPI_NOT_ISR, status);
+	} else if (index < (num_gpes + ACPI_NUM_FIXED_EVENTS))
+		result = acpi_get_event_status(index - num_gpes, status);
+
+	/*
+	 * sleep/power button GPE/Fixed Event is enabled after acpi_system_init,
+	 * check the status at runtime and mark it as valid once it's enabled
+	 */
+	if (!result && (*status & ACPI_EVENT_FLAG_ENABLED))
+		all_counters[index].flags |= ACPI_EVENT_VALID;
+end:
+	return result;
+}
+
 static ssize_t counter_show(struct kobject *kobj,
 	struct kobj_attribute *attr, char *buf)
 {
-	all_counters[num_gpes + ACPI_NUM_FIXED_EVENTS + COUNT_SCI] =
+	int index = attr - counter_attrs;
+	int size;
+	acpi_handle handle;
+	acpi_event_status status;
+	int result = 0;
+
+	all_counters[num_gpes + ACPI_NUM_FIXED_EVENTS + COUNT_SCI].count =
 		acpi_irq_handled;
-	all_counters[num_gpes + ACPI_NUM_FIXED_EVENTS + COUNT_GPE] =
+	all_counters[num_gpes + ACPI_NUM_FIXED_EVENTS + COUNT_GPE].count =
 		acpi_gpe_count;
 
-	return sprintf(buf, "%d\n", all_counters[attr - counter_attrs]);
+	size = sprintf(buf, "%8d", all_counters[index].count);
+
+	/* "gpe_all" or "sci" */
+	if (index >= num_gpes + ACPI_NUM_FIXED_EVENTS)
+		goto end;
+
+	result = get_status(index, &status, &handle);
+	if (result)
+		goto end;
+
+	if (!(all_counters[index].flags & ACPI_EVENT_VALID))
+		size += sprintf(buf + size, "  invalid");
+	else if (status & ACPI_EVENT_FLAG_ENABLED)
+		size += sprintf(buf + size, "	enable");
+	else
+		size += sprintf(buf + size, "  disable");
+
+end:
+	size += sprintf(buf + size, "\n");
+	return result ? result : size;
 }
 
 /*
  * counter_set() sets the specified counter.
  * setting the total "sci" file to any value clears all counters.
+ * enable/disable/clear a gpe/fixed event in user space.
  */
 static ssize_t counter_set(struct kobject *kobj,
 	struct kobj_attribute *attr, const char *buf, size_t size)
 {
 	int index = attr - counter_attrs;
+	acpi_event_status status;
+	acpi_handle handle;
+	int result = 0;
 
 	if (index == num_gpes + ACPI_NUM_FIXED_EVENTS + COUNT_SCI) {
 		int i;
 		for (i = 0; i < num_counters; ++i)
-			all_counters[i] = 0;
+			all_counters[i].count = 0;
 		acpi_gpe_count = 0;
 		acpi_irq_handled = 0;
+		goto end;
+	}
 
+	/* show the event status for both GPEs and Fixed Events */
+	result = get_status(index, &status, &handle);
+	if (result)
+		goto end;
+
+	if (!(all_counters[index].flags & ACPI_EVENT_VALID)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_WARN,
+			"Can not change Invalid GPE/Fixed Event status\n"));
+		return -EINVAL;
+	}
+
+	if (index < num_gpes) {
+		if (!strcmp(buf, "disable\n") &&
+				(status & ACPI_EVENT_FLAG_ENABLED))
+			result = acpi_disable_gpe(handle, index, ACPI_NOT_ISR);
+		else if (!strcmp(buf, "enable\n") &&
+				!(status & ACPI_EVENT_FLAG_ENABLED))
+			result = acpi_enable_gpe(handle, index, ACPI_NOT_ISR);
+		else if (!strcmp(buf, "clear\n") &&
+				(status & ACPI_EVENT_FLAG_SET))
+			result = acpi_clear_gpe(handle, index, ACPI_NOT_ISR);
+		else
+			all_counters[index].count = strtoul(buf, NULL, 0);
+	} else if (index < num_gpes + ACPI_NUM_FIXED_EVENTS) {
+		int event = index - num_gpes;
+		if (!strcmp(buf, "disable\n") &&
+				(status & ACPI_EVENT_FLAG_ENABLED))
+			result = acpi_disable_event(event, ACPI_NOT_ISR);
+		else if (!strcmp(buf, "enable\n") &&
+				!(status & ACPI_EVENT_FLAG_ENABLED))
+			result = acpi_enable_event(event, ACPI_NOT_ISR);
+		else if (!strcmp(buf, "clear\n") &&
+				(status & ACPI_EVENT_FLAG_SET))
+			result = acpi_clear_event(event);
+		else
+			all_counters[index].count = strtoul(buf, NULL, 0);
 	} else
-		all_counters[index] = strtoul(buf, NULL, 0);
+		all_counters[index].count = strtoul(buf, NULL, 0);
 
-	return size;
+	if (ACPI_FAILURE(result))
+		result = -EINVAL;
+end:
+	return result ? result : size;
 }
 
 void acpi_irq_stats_init(void)
@@ -298,7 +440,8 @@ void acpi_irq_stats_init(void)
 	if (all_attrs == NULL)
 		return;
 
-	all_counters = kzalloc(sizeof(u32) * (num_counters), GFP_KERNEL);
+	all_counters = kzalloc(sizeof(struct event_counter) * (num_counters),
+				GFP_KERNEL);
 	if (all_counters == NULL)
 		goto fail;