[PATCH 67/140] ACPICA: Re-implement interpreters' "serialized mode"

Len Brown
2007-02-07T18:54:38Z

From: Bob Moore <robert.moore@intel.com>

Enhanced the implementation of the interpreters'
serialized mode (boot with "acpi_serialize" to set
acpi_glb_all_methods_serialized flag.)
When this mode is specified, instead of creating a serialization
semaphore per control method, the interpreter lock is
simply no longer released before a blocking operation
during control method execution. This effectively makes
the AML Interpreter single-threaded. The overhead of a
semaphore per-method is eliminated.

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/acpi/events/evregion.c | 15 ++----
drivers/acpi/events/evxface.c | 6 +--
drivers/acpi/executer/excreate.c | 5 +--
drivers/acpi/executer/exsystem.c | 30 +++--------
drivers/acpi/executer/exutils.c | 108 +++++++++++++++++++++++++++++-------
drivers/acpi/namespace/nseval.c | 11 +---
drivers/acpi/namespace/nsinit.c | 7 +--
drivers/acpi/namespace/nsxfeval.c | 11 ++---
include/acpi/acinterp.h | 6 ++-
9 files changed, 114 insertions(+), 85 deletions(-)

diff --git a/drivers/acpi/events/evregion.c b/drivers/acpi/events/evregion.c
index 21caae0..ef45971 100644
--- a/drivers/acpi/events/evregion.c
+++ b/drivers/acpi/events/evregion.c
@@ -291,7 +291,6 @@ acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
u32 bit_width, acpi_integer * value)
{
acpi_status status;
- acpi_status status2;
acpi_adr_space_handler handler;
acpi_adr_space_setup region_setup;
union acpi_operand_object *handler_desc;
@@ -345,7 +344,7 @@ acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
* setup will potentially execute control methods
* (e.g., _REG method for this region)
*/
- acpi_ex_exit_interpreter();
+ acpi_ex_relinquish_interpreter();

status = region_setup(region_obj, ACPI_REGION_ACTIVATE,
handler_desc->address_space.context,
@@ -353,10 +352,7 @@ acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,

/* Re-enter the interpreter */

- status2 = acpi_ex_enter_interpreter();
- if (ACPI_FAILURE(status2)) {
- return_ACPI_STATUS(status2);
- }
+ acpi_ex_reacquire_interpreter();

/* Check for failure of the Region Setup */

@@ -409,7 +405,7 @@ acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
* exit the interpreter because the handler *might* block -- we don't
* know what it will do, so we can't hold the lock on the intepreter.
*/
- acpi_ex_exit_interpreter();
+ acpi_ex_relinquish_interpreter();
}

/* Call the handler */
@@ -430,10 +426,7 @@ acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
* We just returned from a non-default handler, we must re-enter the
* interpreter
*/
- status2 = acpi_ex_enter_interpreter();
- if (ACPI_FAILURE(status2)) {
- return_ACPI_STATUS(status2);
- }
+ acpi_ex_reacquire_interpreter();
}

return_ACPI_STATUS(status);
diff --git a/drivers/acpi/events/evxface.c b/drivers/acpi/events/evxface.c
index 923fd2b..a2af48e 100644
--- a/drivers/acpi/events/evxface.c
+++ b/drivers/acpi/events/evxface.c
@@ -768,11 +768,9 @@ acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
return (AE_BAD_PARAMETER);
}

- status = acpi_ex_enter_interpreter();
- if (ACPI_FAILURE(status)) {
- return (status);
- }
+ /* Must lock interpreter to prevent race conditions */

+ acpi_ex_enter_interpreter();
status = acpi_ev_acquire_global_lock(timeout);
acpi_ex_exit_interpreter();

diff --git a/drivers/acpi/executer/excreate.c b/drivers/acpi/executer/excreate.c
index a4d29b2..c665aa7 100644
--- a/drivers/acpi/executer/excreate.c
+++ b/drivers/acpi/executer/excreate.c
@@ -583,10 +583,7 @@ acpi_ex_create_method(u8 * aml_start,
* Get the sync_level. If method is serialized, a mutex will be
* created for this method when it is parsed.
*/
- if (acpi_gbl_all_methods_serialized) {
- obj_desc->method.sync_level = 0;
- obj_desc->method.method_flags |= AML_METHOD_SERIALIZED;
- } else if (method_flags & AML_METHOD_SERIALIZED) {
+ if (method_flags & AML_METHOD_SERIALIZED) {
/*
* ACPI 1.0: sync_level = 0
* ACPI 2.0: sync_level = sync_level in method declaration
diff --git a/drivers/acpi/executer/exsystem.c b/drivers/acpi/executer/exsystem.c
index 3b9736a..7e5aeb1 100644
--- a/drivers/acpi/executer/exsystem.c
+++ b/drivers/acpi/executer/exsystem.c
@@ -66,7 +66,6 @@ ACPI_MODULE_NAME("exsystem")
acpi_status acpi_ex_system_wait_semaphore(acpi_semaphore semaphore, u16 timeout)
{
acpi_status status;
- acpi_status status2;

ACPI_FUNCTION_TRACE(ex_system_wait_semaphore);

@@ -79,7 +78,7 @@ acpi_status acpi_ex_system_wait_semaphore(acpi_semaphore semaphore, u16 timeout)

/* We must wait, so unlock the interpreter */

- acpi_ex_exit_interpreter();
+ acpi_ex_relinquish_interpreter();

status = acpi_os_wait_semaphore(semaphore, 1, timeout);

@@ -89,13 +88,7 @@ acpi_status acpi_ex_system_wait_semaphore(acpi_semaphore semaphore, u16 timeout)

/* Reacquire the interpreter */

- status2 = acpi_ex_enter_interpreter();
- if (ACPI_FAILURE(status2)) {
-
- /* Report fatal error, could not acquire interpreter */
-
- return_ACPI_STATUS(status2);
- }
+ acpi_ex_reacquire_interpreter();
}

return_ACPI_STATUS(status);
@@ -119,7 +112,6 @@ acpi_status acpi_ex_system_wait_semaphore(acpi_semaphore semaphore, u16 timeout)
acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)
{
acpi_status status;
- acpi_status status2;

ACPI_FUNCTION_TRACE(ex_system_wait_mutex);

@@ -132,7 +124,7 @@ acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)

/* We must wait, so unlock the interpreter */

- acpi_ex_exit_interpreter();
+ acpi_ex_relinquish_interpreter();

status = acpi_os_acquire_mutex(mutex, timeout);

@@ -142,13 +134,7 @@ acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)

/* Reacquire the interpreter */

- status2 = acpi_ex_enter_interpreter();
- if (ACPI_FAILURE(status2)) {
-
- /* Report fatal error, could not acquire interpreter */
-
- return_ACPI_STATUS(status2);
- }
+ acpi_ex_reacquire_interpreter();
}

return_ACPI_STATUS(status);
@@ -209,20 +195,18 @@ acpi_status acpi_ex_system_do_stall(u32 how_long)

acpi_status acpi_ex_system_do_suspend(acpi_integer how_long)
{
- acpi_status status;
-
ACPI_FUNCTION_ENTRY();

/* Since this thread will sleep, we must release the interpreter */

- acpi_ex_exit_interpreter();
+ acpi_ex_relinquish_interpreter();

acpi_os_sleep(how_long);

/* And now we must get the interpreter again */

- status = acpi_ex_enter_interpreter();
- return (status);
+ acpi_ex_reacquire_interpreter();
+ return (AE_OK);
}

/*******************************************************************************
diff --git a/drivers/acpi/executer/exutils.c b/drivers/acpi/executer/exutils.c
index 982c8b6..72adcf4 100644
--- a/drivers/acpi/executer/exutils.c
+++ b/drivers/acpi/executer/exutils.c
@@ -76,46 +76,72 @@ static u32 acpi_ex_digits_needed(acpi_integer value, u32 base);
*
* PARAMETERS: None
*
- * RETURN: Status
+ * RETURN: None
*
- * DESCRIPTION: Enter the interpreter execution region. Failure to enter
- * the interpreter region is a fatal system error
+ * DESCRIPTION: Enter the interpreter execution region. Failure to enter
+ * the interpreter region is a fatal system error. Used in
+ * conjunction with exit_interpreter.
*
******************************************************************************/

-acpi_status acpi_ex_enter_interpreter(void)
+void acpi_ex_enter_interpreter(void)
{
acpi_status status;

- ACPI_FUNCTION_TRACE(ex_enter_interpreter);
+ ACPI_FUNCTION_TRACE(ex_reacquire_interpreter);

status = acpi_ut_acquire_mutex(ACPI_MTX_INTERPRETER);
if (ACPI_FAILURE(status)) {
- ACPI_ERROR((AE_INFO, "Could not acquire interpreter mutex"));
+ ACPI_ERROR((AE_INFO,
+ "Could not acquire AML Interpreter mutex"));
}

- return_ACPI_STATUS(status);
+ return_VOID;
}

/*******************************************************************************
*
- * FUNCTION: acpi_ex_exit_interpreter
+ * FUNCTION: acpi_ex_reacquire_interpreter
*
* PARAMETERS: None
*
* RETURN: None
*
- * DESCRIPTION: Exit the interpreter execution region
+ * DESCRIPTION: Reacquire the interpreter execution region from within the
+ * interpreter code. Failure to enter the interpreter region is a
+ * fatal system error. Used in conjuction with
+ * relinquish_interpreter
+ *
+ ******************************************************************************/
+
+void acpi_ex_reacquire_interpreter(void)
+{
+
+ ACPI_FUNCTION_TRACE(ex_reacquire_interpreter);
+
+ /*
+ * If the global serialized flag is set, do not release the interpreter,
+ * since it was not actually released by acpi_ex_relinquish_interpreter.
+ * This forces the interpreter to be single threaded.
+ */
+ if (!acpi_gbl_all_methods_serialized) {
+ acpi_ex_enter_interpreter();
+ }
+
+ return_VOID;
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ex_exit_interpreter
+ *
+ * PARAMETERS: None
+ *
+ * RETURN: None
*
- * Cases where the interpreter is unlocked:
- * 1) Completion of the execution of a control method
- * 2) Method blocked on a Sleep() AML opcode
- * 3) Method blocked on an Acquire() AML opcode
- * 4) Method blocked on a Wait() AML opcode
- * 5) Method blocked to acquire the global lock
- * 6) Method blocked to execute a serialized control method that is
- * already executing
- * 7) About to invoke a user-installed opregion handler
+ * DESCRIPTION: Exit the interpreter execution region. This is the top level
+ * routine used to exit the interpreter when all processing has
+ * been completed.
*
******************************************************************************/

@@ -127,7 +153,47 @@ void acpi_ex_exit_interpreter(void)

status = acpi_ut_release_mutex(ACPI_MTX_INTERPRETER);
if (ACPI_FAILURE(status)) {
- ACPI_ERROR((AE_INFO, "Could not release interpreter mutex"));
+ ACPI_ERROR((AE_INFO,
+ "Could not release AML Interpreter mutex"));
+ }
+
+ return_VOID;
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ex_relinquish_interpreter
+ *
+ * PARAMETERS: None
+ *
+ * RETURN: None
+ *
+ * DESCRIPTION: Exit the interpreter execution region, from within the
+ * interpreter - before attempting an operation that will possibly
+ * block the running thread.
+ *
+ * Cases where the interpreter is unlocked internally
+ * 1) Method to be blocked on a Sleep() AML opcode
+ * 2) Method to be blocked on an Acquire() AML opcode
+ * 3) Method to be blocked on a Wait() AML opcode
+ * 4) Method to be blocked to acquire the global lock
+ * 5) Method to be blocked waiting to execute a serialized control method
+ * that is currently executing
+ * 6) About to invoke a user-installed opregion handler
+ *
+ ******************************************************************************/
+
+void acpi_ex_relinquish_interpreter(void)
+{
+
+ ACPI_FUNCTION_TRACE(ex_relinquish_interpreter);
+
+ /*
+ * If the global serialized flag is set, do not release the interpreter.
+ * This forces the interpreter to be single threaded.
+ */
+ if (!acpi_gbl_all_methods_serialized) {
+ acpi_ex_exit_interpreter();
}

return_VOID;
@@ -141,8 +207,8 @@ void acpi_ex_exit_interpreter(void)
*
* RETURN: none
*
- * DESCRIPTION: Truncate a number to 32-bits if the currently executing method
- * belongs to a 32-bit ACPI table.
+ * DESCRIPTION: Truncate an ACPI Integer to 32 bits if the execution mode is
+ * 32-bit, as determined by the revision of the DSDT.
*
******************************************************************************/

diff --git a/drivers/acpi/namespace/nseval.c b/drivers/acpi/namespace/nseval.c
index 4b0a4a8..7156616 100644
--- a/drivers/acpi/namespace/nseval.c
+++ b/drivers/acpi/namespace/nseval.c
@@ -154,11 +154,7 @@ acpi_status acpi_ns_evaluate(struct acpi_evaluate_info *info)
* Execute the method via the interpreter. The interpreter is locked
* here before calling into the AML parser
*/
- status = acpi_ex_enter_interpreter();
- if (ACPI_FAILURE(status)) {
- return_ACPI_STATUS(status);
- }
-
+ acpi_ex_enter_interpreter();
status = acpi_ps_execute_method(info);
acpi_ex_exit_interpreter();
} else {
@@ -182,10 +178,7 @@ acpi_status acpi_ns_evaluate(struct acpi_evaluate_info *info)
* resolution, we must lock it because we could access an opregion.
* The opregion access code assumes that the interpreter is locked.
*/
- status = acpi_ex_enter_interpreter();
- if (ACPI_FAILURE(status)) {
- return_ACPI_STATUS(status);
- }
+ acpi_ex_enter_interpreter();

/* Function has a strange interface */

diff --git a/drivers/acpi/namespace/nsinit.c b/drivers/acpi/namespace/nsinit.c
index aec8488..0d3a42b 100644
--- a/drivers/acpi/namespace/nsinit.c
+++ b/drivers/acpi/namespace/nsinit.c
@@ -213,7 +213,7 @@ acpi_ns_init_one_object(acpi_handle obj_handle,
u32 level, void *context, void **return_value)
{
acpi_object_type type;
- acpi_status status;
+ acpi_status status = AE_OK;
struct acpi_init_walk_info *info =
(struct acpi_init_walk_info *)context;
struct acpi_namespace_node *node =
@@ -267,10 +267,7 @@ acpi_ns_init_one_object(acpi_handle obj_handle,
/*
* Must lock the interpreter before executing AML code
*/
- status = acpi_ex_enter_interpreter();
- if (ACPI_FAILURE(status)) {
- return (status);
- }
+ acpi_ex_enter_interpreter();

/*
* Each of these types can contain executable AML code within the
diff --git a/drivers/acpi/namespace/nsxfeval.c b/drivers/acpi/namespace/nsxfeval.c
index dca6799..6a0a46e 100644
--- a/drivers/acpi/namespace/nsxfeval.c
+++ b/drivers/acpi/namespace/nsxfeval.c
@@ -170,7 +170,6 @@ acpi_evaluate_object(acpi_handle handle,
struct acpi_buffer *return_buffer)
{
acpi_status status;
- acpi_status status2;
struct acpi_evaluate_info *info;
acpi_size buffer_space_needed;
u32 i;
@@ -329,14 +328,12 @@ acpi_evaluate_object(acpi_handle handle,
* Delete the internal return object. NOTE: Interpreter must be
* locked to avoid race condition.
*/
- status2 = acpi_ex_enter_interpreter();
- if (ACPI_SUCCESS(status2)) {
+ acpi_ex_enter_interpreter();

- /* Remove one reference on the return object (should delete it) */
+ /* Remove one reference on the return object (should delete it) */

- acpi_ut_remove_reference(info->return_object);
- acpi_ex_exit_interpreter();
- }
+ acpi_ut_remove_reference(info->return_object);
+ acpi_ex_exit_interpreter();
}

cleanup:
diff --git a/include/acpi/acinterp.h b/include/acpi/acinterp.h
index f266b38..8aebe57 100644
--- a/include/acpi/acinterp.h
+++ b/include/acpi/acinterp.h
@@ -445,10 +445,14 @@ acpi_ex_copy_integer_to_buffer_field(union acpi_operand_object *source_desc,
/*
* exutils - interpreter/scanner utilities
*/
-acpi_status acpi_ex_enter_interpreter(void);
+void acpi_ex_enter_interpreter(void);

void acpi_ex_exit_interpreter(void);

+void acpi_ex_reacquire_interpreter(void);
+
+void acpi_ex_relinquish_interpreter(void);
+
void acpi_ex_truncate_for32bit_table(union acpi_operand_object *obj_desc);

u8 acpi_ex_acquire_global_lock(u32 rule);
--
1.5.0.rc3.39.gec804