ACPICA: Add support for host-installed SCI handlers.

This change adds support to allow hosts to install System Control
Interrupt handlers. Certain ACPI functionality requires the host
to handle raw SCIs. For example, the "SCI Doorbell" that is defined
for memory power state support requires the host device driver to
handle SCIs to examine if the doorbell has been activated. Multiple
SCI handlers can be installed to allow for future expansion.
Debugger support is included.
Lv Zheng, Bob Moore. ACPICA BZ 1032.

Bug summary:
It is reported when the PCC (Platform Communication Channel, via
MPST table, defined in ACPI specification 5.0) subchannel responds
to the host, it issues an SCI and the host must probe the subchannel
for channel status.

Buglink: http://bugs.acpica.org/show_bug.cgi?id=1032
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 139 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/evxface.c b/drivers/acpi/acpica/evxface.c
index ca5fba99c33b..6f56146a6f88 100644
--- a/drivers/acpi/acpica/evxface.c
+++ b/drivers/acpi/acpica/evxface.c
@@ -385,6 +385,144 @@ ACPI_EXPORT_SYMBOL(acpi_install_exception_handler)
 #if (!ACPI_REDUCED_HARDWARE)
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_install_sci_handler
+ *
+ * PARAMETERS:  address             - Address of the handler
+ *              context             - Value passed to the handler on each SCI
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Install a handler for a System Control Interrupt.
+ *
+ ******************************************************************************/
+acpi_status acpi_install_sci_handler(acpi_sci_handler address, void *context)
+{
+	struct acpi_sci_handler_info *new_sci_handler;
+	struct acpi_sci_handler_info *sci_handler;
+	acpi_cpu_flags flags;
+	acpi_status status;
+
+	ACPI_FUNCTION_TRACE(acpi_install_sci_handler);
+
+	if (!address) {
+		return_ACPI_STATUS(AE_BAD_PARAMETER);
+	}
+
+	/* Allocate and init a handler object */
+
+	new_sci_handler = ACPI_ALLOCATE(sizeof(struct acpi_sci_handler_info));
+	if (!new_sci_handler) {
+		return_ACPI_STATUS(AE_NO_MEMORY);
+	}
+
+	new_sci_handler->address = address;
+	new_sci_handler->context = context;
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
+	if (ACPI_FAILURE(status)) {
+		goto exit;
+	}
+
+	/* Lock list during installation */
+
+	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
+	sci_handler = acpi_gbl_sci_handler_list;
+
+	/* Ensure handler does not already exist */
+
+	while (sci_handler) {
+		if (address == sci_handler->address) {
+			status = AE_ALREADY_EXISTS;
+			goto unlock_and_exit;
+		}
+
+		sci_handler = sci_handler->next;
+	}
+
+	/* Install the new handler into the global list (at head) */
+
+	new_sci_handler->next = acpi_gbl_sci_handler_list;
+	acpi_gbl_sci_handler_list = new_sci_handler;
+
+      unlock_and_exit:
+
+	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
+	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
+
+      exit:
+	if (ACPI_FAILURE(status)) {
+		ACPI_FREE(new_sci_handler);
+	}
+	return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_remove_sci_handler
+ *
+ * PARAMETERS:  address             - Address of the handler
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Remove a handler for a System Control Interrupt.
+ *
+ ******************************************************************************/
+
+acpi_status acpi_remove_sci_handler(acpi_sci_handler address)
+{
+	struct acpi_sci_handler_info *prev_sci_handler;
+	struct acpi_sci_handler_info *next_sci_handler;
+	acpi_cpu_flags flags;
+	acpi_status status;
+
+	ACPI_FUNCTION_TRACE(acpi_remove_sci_handler);
+
+	if (!address) {
+		return_ACPI_STATUS(AE_BAD_PARAMETER);
+	}
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	/* Remove the SCI handler with lock */
+
+	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
+
+	prev_sci_handler = NULL;
+	next_sci_handler = acpi_gbl_sci_handler_list;
+	while (next_sci_handler) {
+		if (next_sci_handler->address == address) {
+
+			/* Unlink and free the SCI handler info block */
+
+			if (prev_sci_handler) {
+				prev_sci_handler->next = next_sci_handler->next;
+			} else {
+				acpi_gbl_sci_handler_list =
+				    next_sci_handler->next;
+			}
+
+			acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
+			ACPI_FREE(next_sci_handler);
+			goto unlock_and_exit;
+		}
+
+		prev_sci_handler = next_sci_handler;
+		next_sci_handler = next_sci_handler->next;
+	}
+
+	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
+	status = AE_NOT_EXIST;
+
+      unlock_and_exit:
+	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
+	return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_install_global_event_handler
  *
  * PARAMETERS:  handler         - Pointer to the global event handler function
@@ -398,6 +536,7 @@ ACPI_EXPORT_SYMBOL(acpi_install_exception_handler)
  *              Can be used to update event counters, etc.
  *
  ******************************************************************************/
+
 acpi_status
 acpi_install_global_event_handler(acpi_gbl_event_handler handler, void *context)
 {