[PATCH 3/9] ACPICA: Events: Introduce acpi_set_gpe()/acpi_finish_gpe() to reduce divergences.

Lv Zheng
2014-06-18T03:17:51Z

This can help to reduce source code differences between Linux and ACPICA
upstream. Further driver cleanups also require these APIs to eliminate GPE
storms.
1. acpi_set_gpe(): An API that driver should invoke in the case it wants
to disable/enable IRQ without honoring the reference
count implemented in the acpi_disable_gpe() and
acpi_enable_gpe(). Note that this API should only be
invoked inside a acpi_enable_gpe()/acpi_disable_gpe()
pair.
2. acpi_finish_gpe(): Drivers returned ACPI_REENABLE_GPE unset from the
GPE handler should use this API instead of
invoking acpi_set_gpe()/acpi_enable_gpe() to
re-enable the GPE.
The GPE APIs can be invoked inside of a GPE handler or in the task context
with a driver provided lock held. This driver provided lock is safe to be
held in the GPE handler by the driver.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
---
drivers/acpi/acpica/evxfgpe.c | 105 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 105 insertions(+)

diff --git a/drivers/acpi/acpica/evxfgpe.c b/drivers/acpi/acpica/evxfgpe.c
index cb534fa..6c53633 100644
--- a/drivers/acpi/acpica/evxfgpe.c
+++ b/drivers/acpi/acpica/evxfgpe.c
@@ -176,6 +176,68 @@ acpi_status acpi_disable_gpe(acpi_handle gpe_device, u32 gpe_number)

ACPI_EXPORT_SYMBOL(acpi_disable_gpe)

+/*******************************************************************************
+ *
+ * FUNCTION: acpi_set_gpe
+ *
+ * PARAMETERS: gpe_device - Parent GPE Device. NULL for GPE0/GPE1
+ * gpe_number - GPE level within the GPE block
+ * action - ACPI_GPE_ENABLE or ACPI_GPE_DISABLE
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Enable or disable an individual GPE. This function bypasses
+ * the reference count mechanism used in the acpi_enable_gpe and
+ * acpi_disable_gpe interfaces -- and should be used with care.
+ *
+ * Note: Typically used to disable a runtime GPE for short period of time,
+ * then re-enable it, without disturbing the existing reference counts. This
+ * is useful, for example, in the Embedded Controller (EC) driver.
+ *
+ ******************************************************************************/
+acpi_status acpi_set_gpe(acpi_handle gpe_device, u32 gpe_number, u8 action)
+{
+ struct acpi_gpe_event_info *gpe_event_info;
+ acpi_status status;
+ acpi_cpu_flags flags;
+
+ ACPI_FUNCTION_TRACE(acpi_set_gpe);
+
+ flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
+
+ /* Ensure that we have a valid GPE number */
+
+ gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
+ if (!gpe_event_info) {
+ status = AE_BAD_PARAMETER;
+ goto unlock_and_exit;
+ }
+
+ /* Perform the action */
+
+ switch (action) {
+ case ACPI_GPE_ENABLE:
+
+ status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
+ break;
+
+ case ACPI_GPE_DISABLE:
+
+ status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
+ break;
+
+ default:
+
+ status = AE_BAD_PARAMETER;
+ break;
+ }
+
+unlock_and_exit:
+ acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
+ return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_set_gpe)

/*******************************************************************************
*
@@ -479,6 +541,49 @@ unlock_and_exit:

ACPI_EXPORT_SYMBOL(acpi_get_gpe_status)

+/*******************************************************************************
+ *
+ * FUNCTION: acpi_finish_gpe
+ *
+ * PARAMETERS: gpe_device - Namespace node for the GPE Block
+ * (NULL for FADT defined GPEs)
+ * gpe_number - GPE level within the GPE block
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Clear and conditionally reenable a GPE. This completes the GPE
+ * processing. Intended for use by asynchronous host-installed
+ * GPE handlers. The GPE is only reenabled if the enable_for_run bit
+ * is set in the GPE info.
+ *
+ ******************************************************************************/
+acpi_status acpi_finish_gpe(acpi_handle gpe_device, u32 gpe_number)
+{
+ struct acpi_gpe_event_info *gpe_event_info;
+ acpi_status status;
+ acpi_cpu_flags flags;
+
+ ACPI_FUNCTION_TRACE(acpi_finish_gpe);
+
+ flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
+
+ /* Ensure that we have a valid GPE number */
+
+ gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
+ if (!gpe_event_info) {
+ status = AE_BAD_PARAMETER;
+ goto unlock_and_exit;
+ }
+
+ status = acpi_ev_finish_gpe(gpe_event_info);
+
+unlock_and_exit:
+ acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
+ return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_finish_gpe)
+
/******************************************************************************
*
* FUNCTION: acpi_disable_all_gpes
--
1.7.10