[ACPIHP PATCH part1 3/4] ACPIHP: detect ACPI hotplug slots by checking ACPI _EJ0 method
From: Jiang Liu
Date: Sat Nov 03 2012 - 12:08:18 EST
This patch implements a default mechanism to detect and manage ACPI
system device hotplug slots based on standard ACPI interfaces.
1) Detech hotplug slot by checking existence of _EJ0 and _STA methods.
2) Power off a slot by evaluating _EJ0 method.
It's the default hotplug slot enumerating mechanism, platform specifc
drivers may provide advanced implementation to override the default
implementation.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
Signed-off-by: Gaohuai Han <hangaohuai@xxxxxxxxxx>
---
drivers/acpi/hotplug/Makefile | 1 +
drivers/acpi/hotplug/acpihp.h | 1 +
drivers/acpi/hotplug/slot.c | 1 +
drivers/acpi/hotplug/slot_ej0.c | 143 +++++++++++++++++++++++++++++++++++++++
4 files changed, 146 insertions(+)
create mode 100644 drivers/acpi/hotplug/slot_ej0.c
diff --git a/drivers/acpi/hotplug/Makefile b/drivers/acpi/hotplug/Makefile
index 2cbb03c..5420ae7 100644
--- a/drivers/acpi/hotplug/Makefile
+++ b/drivers/acpi/hotplug/Makefile
@@ -7,3 +7,4 @@ acpihp-y = core.o
obj-$(CONFIG_ACPI_HOTPLUG_SLOT) += acpihp_slot.o
acpihp_slot-y = slot.o
+acpihp_slot-y += slot_ej0.o
diff --git a/drivers/acpi/hotplug/acpihp.h b/drivers/acpi/hotplug/acpihp.h
index 7467895..278c8c2 100644
--- a/drivers/acpi/hotplug/acpihp.h
+++ b/drivers/acpi/hotplug/acpihp.h
@@ -28,5 +28,6 @@
#include <acpi/acpi_hotplug.h>
extern struct acpi_device *acpi_root;
+extern struct acpihp_slot_ops acpihp_slot_ej0;
#endif
diff --git a/drivers/acpi/hotplug/slot.c b/drivers/acpi/hotplug/slot.c
index b76cb16..e5861fc 100644
--- a/drivers/acpi/hotplug/slot.c
+++ b/drivers/acpi/hotplug/slot.c
@@ -43,6 +43,7 @@ static struct acpihp_slot_ops *slot_ops_curr;
* The first entry whose init() method returns success will be used.
*/
static struct acpihp_slot_ops *slot_ops_array[] = {
+ &acpihp_slot_ej0,
NULL
};
diff --git a/drivers/acpi/hotplug/slot_ej0.c b/drivers/acpi/hotplug/slot_ej0.c
new file mode 100644
index 0000000..fa987dc
--- /dev/null
+++ b/drivers/acpi/hotplug/slot_ej0.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2012 Huawei Tech. Co., Ltd.
+ * Copyright (C) 2012 Gaohuai Han <hangaohuai@xxxxxxxxxx>
+ * Copyright (C) 2012 Jiang Liu <jiang.liu@xxxxxxxxxx>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/acpi.h>
+#include <acpi/acpi.h>
+#include <acpi/acpi_hotplug.h>
+
+static acpi_status acpihp_slot_ej0_capable(acpi_handle handle)
+{
+ acpi_handle tmp;
+
+ /* Assume a device object with _EJ0 and _STA is a hotplug slot. */
+ if (ACPI_FAILURE(acpi_get_handle(handle, "_EJ0", &tmp)))
+ return AE_ERROR;
+ if (ACPI_FAILURE(acpi_get_handle(handle, METHOD_NAME__STA, &tmp)))
+ return AE_ERROR;
+
+ return AE_OK;
+}
+
+static acpi_status
+acpihp_slot_ej0_check(acpi_handle handle, u32 lvl, void *context, void **rv)
+{
+ acpi_status rc = AE_OK;
+ enum acpihp_dev_type type;
+
+ if (!acpihp_dev_get_type(handle, &type)) {
+ switch (type) {
+ case ACPIHP_DEV_TYPE_CPU:
+ case ACPIHP_DEV_TYPE_MEM:
+ case ACPIHP_DEV_TYPE_HOST_BRIDGE:
+ case ACPIHP_DEV_TYPE_CONTAINER:
+ if (ACPI_SUCCESS(acpihp_slot_ej0_capable(handle))) {
+ *(int *)rv = 1;
+ rc = AE_CTRL_TERMINATE;
+ } else if (type == ACPIHP_DEV_TYPE_HOST_BRIDGE) {
+ rc = AE_CTRL_DEPTH;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+
+ return rc;
+}
+
+static acpi_status acpihp_slot_ej0_init(void)
+{
+ int cap = 0;
+
+ acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, acpihp_slot_ej0_check,
+ NULL, NULL, (void **)&cap);
+ acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, acpihp_slot_ej0_check,
+ NULL, NULL, (void **)&cap);
+
+ return cap ? AE_OK : AE_ERROR;
+}
+
+static acpi_status acpihp_slot_ej0_create(struct acpihp_slot *slot)
+{
+ /*
+ * Assume device objects with _EJ0 are capable of:
+ * ONLINE, OFFLINE, POWEROFF, HOTPLUG
+ */
+ slot->capabilities = ACPIHP_SLOT_CAP_ONLINE | ACPIHP_SLOT_CAP_OFFLINE |
+ ACPIHP_SLOT_CAP_POWEROFF | ACPIHP_SLOT_CAP_HOTPLUG;
+
+ return AE_OK;
+}
+
+static acpi_status acpihp_slot_ej0_poweroff(struct acpihp_slot *slot)
+{
+ acpi_status status;
+ unsigned long long sta;
+ union acpi_object arg;
+ struct acpi_object_list arg_list;
+ acpi_handle handle = slot->handle;
+ acpi_handle dummy_handle;
+
+ if (ACPI_SUCCESS(acpi_get_handle(handle, "_PS3", &dummy_handle))) {
+ status = acpi_evaluate_object(handle, "_PS3", NULL, NULL);
+ if (ACPI_FAILURE(status)) {
+ ACPIHP_SLOT_DEBUG(slot, "fails to evaluate _PS3.\n");
+ return status;
+ }
+ }
+
+ arg_list.count = 1;
+ arg_list.pointer = &arg;
+ arg.type = ACPI_TYPE_INTEGER;
+ arg.integer.value = 1;
+ status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
+ if (ACPI_FAILURE(status)) {
+ ACPIHP_SLOT_WARN(slot, "fails to power off.\n");
+ return status;
+ }
+
+ status = acpi_evaluate_integer(handle, METHOD_NAME__STA, NULL, &sta);
+ if (ACPI_FAILURE(status)) {
+ ACPIHP_SLOT_WARN(slot, "fails to evaluate _STA method\n");
+ return status;
+ }
+
+ if (sta & (ACPI_STA_DEVICE_FUNCTIONING | ACPI_STA_DEVICE_ENABLED)) {
+ ACPIHP_SLOT_WARN(slot,
+ "object is still active after executing _EJ0.\n");
+ return AE_ERROR;
+ }
+
+ return AE_OK;
+}
+
+struct acpihp_slot_ops acpihp_slot_ej0 = {
+ .owner = THIS_MODULE,
+ .desc = "Control Hotplug Slots by ACPI _EJ0 Method",
+ .init = acpihp_slot_ej0_init,
+ .check = acpihp_slot_ej0_capable,
+ .create = acpihp_slot_ej0_create,
+ .poweroff = acpihp_slot_ej0_poweroff,
+};
--
1.7.9.5
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