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, 73 insertions, 7 deletions

diff --git a/drivers/acpi/acpica/evsci.c b/drivers/acpi/acpica/evsci.c
index b905acf7aacd..b2f0fb2f57b4 100644
--- a/drivers/acpi/acpica/evsci.c
+++ b/drivers/acpi/acpica/evsci.c
@@ -54,6 +54,52 @@ static u32 ACPI_SYSTEM_XFACE acpi_ev_sci_xrupt_handler(void *context);
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_ev_sci_dispatch
+ *
+ * PARAMETERS:  None
+ *
+ * RETURN:      Status code indicates whether interrupt was handled.
+ *
+ * DESCRIPTION: Dispatch the SCI to all host-installed SCI handlers.
+ *
+ ******************************************************************************/
+
+u32 acpi_ev_sci_dispatch(void)
+{
+	struct acpi_sci_handler_info *sci_handler;
+	acpi_cpu_flags flags;
+	u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
+
+	ACPI_FUNCTION_NAME(ev_sci_dispatch);
+
+	/* Are there any host-installed SCI handlers? */
+
+	if (!acpi_gbl_sci_handler_list) {
+		return (int_status);
+	}
+
+	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
+
+	/* Invoke all host-installed SCI handlers */
+
+	sci_handler = acpi_gbl_sci_handler_list;
+	while (sci_handler) {
+
+		/* Invoke the installed handler (at interrupt level) */
+
+		int_status |= sci_handler->address((u32)acpi_gbl_FADT.
+						   sci_interrupt,
+						   sci_handler->context);
+
+		sci_handler = sci_handler->next;
+	}
+
+	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
+	return (int_status);
+}
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_ev_sci_xrupt_handler
  *
  * PARAMETERS:  context   - Calling Context
@@ -89,6 +135,10 @@ static u32 ACPI_SYSTEM_XFACE acpi_ev_sci_xrupt_handler(void *context)
 	 */
 	interrupt_handled |= acpi_ev_gpe_detect(gpe_xrupt_list);
 
+	/* Invoke all host-installed SCI handlers */
+
+	interrupt_handled |= acpi_ev_sci_dispatch();
+
 	return_UINT32(interrupt_handled);
 }
 
@@ -112,14 +162,13 @@ u32 ACPI_SYSTEM_XFACE acpi_ev_gpe_xrupt_handler(void *context)
 	ACPI_FUNCTION_TRACE(ev_gpe_xrupt_handler);
 
 	/*
-	 * We are guaranteed by the ACPI CA initialization/shutdown code that
+	 * We are guaranteed by the ACPICA initialization/shutdown code that
 	 * if this interrupt handler is installed, ACPI is enabled.
 	 */
 
 	/* GPEs: Check for and dispatch any GPEs that have occurred */
 
 	interrupt_handled |= acpi_ev_gpe_detect(gpe_xrupt_list);
-
 	return_UINT32(interrupt_handled);
 }
 
@@ -150,15 +199,15 @@ u32 acpi_ev_install_sci_handler(void)
 
 /******************************************************************************
  *
- * FUNCTION:    acpi_ev_remove_sci_handler
+ * FUNCTION:    acpi_ev_remove_all_sci_handlers
  *
  * PARAMETERS:  none
  *
- * RETURN:      E_OK if handler uninstalled OK, E_ERROR if handler was not
+ * RETURN:      AE_OK if handler uninstalled, AE_ERROR if handler was not
  *              installed to begin with
  *
  * DESCRIPTION: Remove the SCI interrupt handler. No further SCIs will be
- *              taken.
+ *              taken. Remove all host-installed SCI handlers.
  *
  * Note:  It doesn't seem important to disable all events or set the event
  *        enable registers to their original values. The OS should disable
@@ -167,11 +216,13 @@ u32 acpi_ev_install_sci_handler(void)
  *
  ******************************************************************************/
 
-acpi_status acpi_ev_remove_sci_handler(void)
+acpi_status acpi_ev_remove_all_sci_handlers(void)
 {
+	struct acpi_sci_handler_info *sci_handler;
+	acpi_cpu_flags flags;
 	acpi_status status;
 
-	ACPI_FUNCTION_TRACE(ev_remove_sci_handler);
+	ACPI_FUNCTION_TRACE(ev_remove_all_sci_handlers);
 
 	/* Just let the OS remove the handler and disable the level */
 
@@ -179,6 +230,21 @@ acpi_status acpi_ev_remove_sci_handler(void)
 	    acpi_os_remove_interrupt_handler((u32) acpi_gbl_FADT.sci_interrupt,
 					     acpi_ev_sci_xrupt_handler);
 
+	if (!acpi_gbl_sci_handler_list) {
+		return (status);
+	}
+
+	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
+
+	/* Free all host-installed SCI handlers */
+
+	while (acpi_gbl_sci_handler_list) {
+		sci_handler = acpi_gbl_sci_handler_list;
+		acpi_gbl_sci_handler_list = sci_handler->next;
+		ACPI_FREE(sci_handler);
+	}
+
+	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 	return_ACPI_STATUS(status);
 }