ACPI / sysfs: Update method tracing facility.

This patch updates the method tracing facility as the acpi_debug_trace()
API has been updated to allow it to trace AML interpreter execution, the
meanings and the usages of the API parameters are changed due to the
updates.

The new API:
1. Uses ACPI_TRACE_ENABLED flag to indicate the enabling of the tracer;
2. Allows tracer still can be enabled when method name is not specified so
   that the AML interpreter execution can be traced without knowing the
   method name, which is useful for kernel boot tracing;
3. Supports arbitrary full path name, it doesn't need to be a name related
   to an entrance of acpi_evaluate_object().

Note that the sysfs parameters are also updated so that when reading the
attribute files, ACPICA internal settings are returned.

In order to make the sysfs parameters (acpi.trace_state) available during
boot, this patch adds code to bypass ACPICA semaphore/mutex invocations
when acpi mutex utilities haven't been initialized.

This patch doesn't update documentation of method tracing facility, it will
be updated by further patches.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 3b8963f21b36..6341cb523dc4 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -83,6 +83,7 @@ static void *acpi_irq_context;
 static struct workqueue_struct *kacpid_wq;
 static struct workqueue_struct *kacpi_notify_wq;
 static struct workqueue_struct *kacpi_hotplug_wq;
+static bool acpi_os_initialized;
 
 /*
  * This list of permanent mappings is for memory that may be accessed from
@@ -1316,6 +1317,9 @@ acpi_status acpi_os_wait_semaphore(acpi_handle handle, u32 units, u16 timeout)
 	long jiffies;
 	int ret = 0;
 
+	if (!acpi_os_initialized)
+		return AE_OK;
+
 	if (!sem || (units < 1))
 		return AE_BAD_PARAMETER;
 
@@ -1355,6 +1359,9 @@ acpi_status acpi_os_signal_semaphore(acpi_handle handle, u32 units)
 {
 	struct semaphore *sem = (struct semaphore *)handle;
 
+	if (!acpi_os_initialized)
+		return AE_OK;
+
 	if (!sem || (units < 1))
 		return AE_BAD_PARAMETER;
 
@@ -1863,6 +1870,7 @@ acpi_status __init acpi_os_initialize(void)
 		rv = acpi_os_map_generic_address(&acpi_gbl_FADT.reset_register);
 		pr_debug(PREFIX "%s: map reset_reg status %d\n", __func__, rv);
 	}
+	acpi_os_initialized = true;
 
 	return AE_OK;
 }