ACPI: Use GPE reference counting to support shared GPEs

ACPI GPEs may map to multiple devices.  The current GPE interface
only provides a mechanism for enabling and disabling GPEs, making
it difficult to change the state of GPEs at runtime without extensive
cooperation between devices.

Add an API to allow devices to indicate whether or not they want
their device's GPE to be enabled for both runtime and wakeup events.

Remove the old GPE type handling entirely, which gets rid of various
quirks, like the implicit disabling with GPE type setting. This
requires a small amount of rework in order to ensure that non-wake
GPEs are enabled by default to preserve existing behaviour.

Based on patches from Matthew Garrett <mjg@redhat.com>.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 16 insertions, 137 deletions

diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c
index afacf4416c73..30ca3a30ef00 100644
--- a/drivers/acpi/acpica/evgpe.c
+++ b/drivers/acpi/acpica/evgpe.c
@@ -54,54 +54,9 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context);
 
 /*******************************************************************************
  *
- * FUNCTION:    acpi_ev_set_gpe_type
- *
- * PARAMETERS:  gpe_event_info          - GPE to set
- *              Type                    - New type
- *
- * RETURN:      Status
- *
- * DESCRIPTION: Sets the new type for the GPE (wake, run, or wake/run)
- *
- ******************************************************************************/
-
-acpi_status
-acpi_ev_set_gpe_type(struct acpi_gpe_event_info *gpe_event_info, u8 type)
-{
-        acpi_status status;
-
-        ACPI_FUNCTION_TRACE(ev_set_gpe_type);
-
-        /* Validate type and update register enable masks */
-
-        switch (type) {
-        case ACPI_GPE_TYPE_WAKE:
-        case ACPI_GPE_TYPE_RUNTIME:
-        case ACPI_GPE_TYPE_WAKE_RUN:
-                break;
-
-        default:
-                return_ACPI_STATUS(AE_BAD_PARAMETER);
-        }
-
-        /* Disable the GPE if currently enabled */
-
-        status = acpi_ev_disable_gpe(gpe_event_info);
-
-        /* Clear the type bits and insert the new Type */
-
-        gpe_event_info->flags &= ~ACPI_GPE_TYPE_MASK;
-        gpe_event_info->flags |= type;
-        return_ACPI_STATUS(status);
-}
-
-/*******************************************************************************
- *
  * FUNCTION:    acpi_ev_update_gpe_enable_masks
  *
  * PARAMETERS:  gpe_event_info          - GPE to update
- *              Type                    - What to do: ACPI_GPE_DISABLE or
- *                                        ACPI_GPE_ENABLE
  *
  * RETURN:      Status
  *
@@ -110,8 +65,7 @@ acpi_ev_set_gpe_type(struct acpi_gpe_event_info *gpe_event_info, u8 type)
  ******************************************************************************/
 
 acpi_status
-acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info,
-                                u8 type)
+acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info)
 {
         struct acpi_gpe_register_info *gpe_register_info;
         u8 register_bit;
@@ -127,37 +81,14 @@ acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info,
             (1 <<
              (gpe_event_info->gpe_number - gpe_register_info->base_gpe_number));
 
-        /* 1) Disable case. Simply clear all enable bits */
-
-        if (type == ACPI_GPE_DISABLE) {
-                ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake,
-                               register_bit);
-                ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
-                return_ACPI_STATUS(AE_OK);
-        }
-
-        /* 2) Enable case. Set/Clear the appropriate enable bits */
+        ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake, register_bit);
+        ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
 
-        switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
-        case ACPI_GPE_TYPE_WAKE:
-                ACPI_SET_BIT(gpe_register_info->enable_for_wake, register_bit);
-                ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
-                break;
-
-        case ACPI_GPE_TYPE_RUNTIME:
-                ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake,
-                               register_bit);
+        if (gpe_event_info->runtime_count)
                 ACPI_SET_BIT(gpe_register_info->enable_for_run, register_bit);
-                break;
 
-        case ACPI_GPE_TYPE_WAKE_RUN:
+        if (gpe_event_info->wakeup_count)
                 ACPI_SET_BIT(gpe_register_info->enable_for_wake, register_bit);
-                ACPI_SET_BIT(gpe_register_info->enable_for_run, register_bit);
-                break;
-
-        default:
-                return_ACPI_STATUS(AE_BAD_PARAMETER);
-        }
 
         return_ACPI_STATUS(AE_OK);
 }
@@ -186,47 +117,20 @@ acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info,
 
         /* Make sure HW enable masks are updated */
 
-        status =
-            acpi_ev_update_gpe_enable_masks(gpe_event_info, ACPI_GPE_ENABLE);
-        if (ACPI_FAILURE(status)) {
+        status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
+        if (ACPI_FAILURE(status))
                 return_ACPI_STATUS(status);
-        }
 
         /* Mark wake-enabled or HW enable, or both */
 
-        switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
-        case ACPI_GPE_TYPE_WAKE:
-
-                ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
-                break;
-
-        case ACPI_GPE_TYPE_WAKE_RUN:
-
-                ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
-
-                /*lint -fallthrough */
-
-        case ACPI_GPE_TYPE_RUNTIME:
-
-                ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_RUN_ENABLED);
-
-                if (write_to_hardware) {
-
-                        /* Clear the GPE (of stale events), then enable it */
-
-                        status = acpi_hw_clear_gpe(gpe_event_info);
-                        if (ACPI_FAILURE(status)) {
-                                return_ACPI_STATUS(status);
-                        }
-
-                        /* Enable the requested runtime GPE */
-
-                        status = acpi_hw_write_gpe_enable_reg(gpe_event_info);
-                }
-                break;
+        if (gpe_event_info->runtime_count && write_to_hardware) {
+                /* Clear the GPE (of stale events), then enable it */
+                status = acpi_hw_clear_gpe(gpe_event_info);
+                if (ACPI_FAILURE(status))
+                        return_ACPI_STATUS(status);
 
-        default:
-                return_ACPI_STATUS(AE_BAD_PARAMETER);
+                /* Enable the requested runtime GPE */
+                status = acpi_hw_write_gpe_enable_reg(gpe_event_info);
         }
 
         return_ACPI_STATUS(AE_OK);
@@ -252,34 +156,9 @@ acpi_status acpi_ev_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 
         /* Make sure HW enable masks are updated */
 
-        status =
-            acpi_ev_update_gpe_enable_masks(gpe_event_info, ACPI_GPE_DISABLE);
-        if (ACPI_FAILURE(status)) {
+        status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
+        if (ACPI_FAILURE(status))
                 return_ACPI_STATUS(status);
-        }
-
-        /* Clear the appropriate enabled flags for this GPE */
-
-        switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
-        case ACPI_GPE_TYPE_WAKE:
-                ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
-                break;
-
-        case ACPI_GPE_TYPE_WAKE_RUN:
-                ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
-
-                /* fallthrough */
-
-        case ACPI_GPE_TYPE_RUNTIME:
-
-                /* Disable the requested runtime GPE */
-
-                ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_RUN_ENABLED);
-                break;
-
-        default:
-                break;
-        }
 
         /*
          * Even if we don't know the GPE type, make sure that we always