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, 33 insertions, 54 deletions

diff --git a/drivers/acpi/acpica/evgpeblk.c b/drivers/acpi/acpica/evgpeblk.c
index 247920900187..3d4c4aca11cd 100644
--- a/drivers/acpi/acpica/evgpeblk.c
+++ b/drivers/acpi/acpica/evgpeblk.c
@@ -258,7 +258,6 @@ acpi_ev_save_method_info(acpi_handle obj_handle,
         u32 gpe_number;
         char name[ACPI_NAME_SIZE + 1];
         u8 type;
-        acpi_status status;
 
         ACPI_FUNCTION_TRACE(ev_save_method_info);
 
@@ -325,26 +324,20 @@ acpi_ev_save_method_info(acpi_handle obj_handle,
 
         /*
          * Now we can add this information to the gpe_event_info block for use
-         * during dispatch of this GPE. Default type is RUNTIME, although this may
-         * change when the _PRW methods are executed later.
+         * during dispatch of this GPE.
          */
         gpe_event_info =
             &gpe_block->event_info[gpe_number - gpe_block->block_base_number];
 
-        gpe_event_info->flags = (u8)
-            (type | ACPI_GPE_DISPATCH_METHOD | ACPI_GPE_TYPE_RUNTIME);
+        gpe_event_info->flags = (u8) (type | ACPI_GPE_DISPATCH_METHOD);
 
         gpe_event_info->dispatch.method_node =
             (struct acpi_namespace_node *)obj_handle;
 
-        /* Update enable mask, but don't enable the HW GPE as of yet */
-
-        status = acpi_ev_enable_gpe(gpe_event_info, FALSE);
-
         ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
                           "Registered GPE method %s as GPE number 0x%.2X\n",
                           name, gpe_number));
-        return_ACPI_STATUS(status);
+        return_ACPI_STATUS(AE_OK);
 }
 
 /*******************************************************************************
@@ -454,20 +447,7 @@ acpi_ev_match_prw_and_gpe(acpi_handle obj_handle,
                                                         gpe_block->
                                                         block_base_number];
 
-                /* Mark GPE for WAKE-ONLY but WAKE_DISABLED */
-
-                gpe_event_info->flags &=
-                    ~(ACPI_GPE_WAKE_ENABLED | ACPI_GPE_RUN_ENABLED);
-
-                status =
-                    acpi_ev_set_gpe_type(gpe_event_info, ACPI_GPE_TYPE_WAKE);
-                if (ACPI_FAILURE(status)) {
-                        goto cleanup;
-                }
-
-                status =
-                    acpi_ev_update_gpe_enable_masks(gpe_event_info,
-                                                    ACPI_GPE_DISABLE);
+                gpe_event_info->flags |= ACPI_GPE_CAN_WAKE;
         }
 
       cleanup:
@@ -989,7 +969,6 @@ acpi_status
 acpi_ev_initialize_gpe_block(struct acpi_namespace_node *gpe_device,
                              struct acpi_gpe_block_info *gpe_block)
 {
-        acpi_status status;
         struct acpi_gpe_event_info *gpe_event_info;
         struct acpi_gpe_walk_info gpe_info;
         u32 wake_gpe_count;
@@ -1019,42 +998,50 @@ acpi_ev_initialize_gpe_block(struct acpi_namespace_node *gpe_device,
                 gpe_info.gpe_block = gpe_block;
                 gpe_info.gpe_device = gpe_device;
 
-                status =
-                    acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+                acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
                                            ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
                                            acpi_ev_match_prw_and_gpe, NULL,
                                            &gpe_info, NULL);
         }
 
         /*
-         * Enable all GPEs in this block that have these attributes:
-         * 1) are "runtime" or "run/wake" GPEs, and
-         * 2) have a corresponding _Lxx or _Exx method
-         *
-         * Any other GPEs within this block must be enabled via the
-         * acpi_enable_gpe() external interface.
+         * Enable all GPEs that have a corresponding method and aren't
+         * capable of generating wakeups. Any other GPEs within this block
+         * must be enabled via the acpi_enable_gpe() interface.
          */
         wake_gpe_count = 0;
         gpe_enabled_count = 0;
+        if (gpe_device == acpi_gbl_fadt_gpe_device)
+                gpe_device = NULL;
 
         for (i = 0; i < gpe_block->register_count; i++) {
-                for (j = 0; j < 8; j++) {
+                for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
+                        acpi_status status;
+                        acpi_size gpe_index;
+                        int gpe_number;
 
                         /* Get the info block for this particular GPE */
+                        gpe_index = (acpi_size)i * ACPI_GPE_REGISTER_WIDTH + j;
+                        gpe_event_info = &gpe_block->event_info[gpe_index];
 
-                        gpe_event_info = &gpe_block->event_info[((acpi_size) i *
-                                                                 ACPI_GPE_REGISTER_WIDTH)
-                                                                + j];
-
-                        if (((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
-                             ACPI_GPE_DISPATCH_METHOD) &&
-                            (gpe_event_info->flags & ACPI_GPE_TYPE_RUNTIME)) {
-                                gpe_enabled_count++;
-                        }
-
-                        if (gpe_event_info->flags & ACPI_GPE_TYPE_WAKE) {
+                        if (gpe_event_info->flags & ACPI_GPE_CAN_WAKE) {
                                 wake_gpe_count++;
+                                if (acpi_gbl_leave_wake_gpes_disabled)
+                                        continue;
                         }
+
+                        if (!(gpe_event_info->flags & ACPI_GPE_DISPATCH_METHOD))
+                                continue;
+
+                        gpe_number = gpe_index + gpe_block->block_base_number;
+                        status = acpi_enable_gpe(gpe_device, gpe_number,
+                                                ACPI_GPE_TYPE_RUNTIME);
+                        if (ACPI_FAILURE(status))
+                                ACPI_ERROR((AE_INFO,
+                                                "Failed to enable GPE %02X\n",
+                                                gpe_number));
+                        else
+                                gpe_enabled_count++;
                 }
         }
 
@@ -1062,15 +1049,7 @@ acpi_ev_initialize_gpe_block(struct acpi_namespace_node *gpe_device,
                           "Found %u Wake, Enabled %u Runtime GPEs in this block\n",
                           wake_gpe_count, gpe_enabled_count));
 
-        /* Enable all valid runtime GPEs found above */
-
-        status = acpi_hw_enable_runtime_gpe_block(NULL, gpe_block, NULL);
-        if (ACPI_FAILURE(status)) {
-                ACPI_ERROR((AE_INFO, "Could not enable GPEs in GpeBlock %p",
-                            gpe_block));
-        }
-
-        return_ACPI_STATUS(status);
+        return_ACPI_STATUS(AE_OK);
 }
 
 /*******************************************************************************