[RFC PATCH v3 06/28] ACPIHP: introduce interfaces to scan and walk ACPI devices connecting to a slot
From: Jiang Liu
Date: Sat Oct 06 2012 - 11:30:38 EST
This patch enhances acpi_bus_scan() to implement acpihp_add_devices(),
which creates ACPI devices for hot-added system devices connecting to
an ACPI hotplug slot, but don't cross the slot boundary.
It also introduces a new interface to walk all ACPI devices connecting
to an ACPI hotplug slot.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
Signed-off-by: Hanjun Guo <guohanjun@xxxxxxxxxx>
Signed-off-by: Gaohuai Han <hangaohuai@xxxxxxxxxx>
---
drivers/acpi/hotplug/Makefile | 2 +-
drivers/acpi/hotplug/acpihp.h | 1 +
drivers/acpi/hotplug/device.c | 123 +++++++++++++++++++++++++++++++++++++++++
drivers/acpi/internal.h | 2 +
drivers/acpi/scan.c | 11 +++-
include/acpi/acpi_bus.h | 2 +
include/acpi/acpi_hotplug.h | 15 +++++
7 files changed, 154 insertions(+), 2 deletions(-)
create mode 100644 drivers/acpi/hotplug/device.c
diff --git a/drivers/acpi/hotplug/Makefile b/drivers/acpi/hotplug/Makefile
index c19b350..6e5daf6 100644
--- a/drivers/acpi/hotplug/Makefile
+++ b/drivers/acpi/hotplug/Makefile
@@ -3,7 +3,7 @@
#
obj-$(CONFIG_ACPI_HOTPLUG) += acpihp.o
-acpihp-y = core.o
+acpihp-y = core.o device.o
obj-$(CONFIG_ACPI_HOTPLUG_SLOT) += acpihp_slot.o
acpihp_slot-y = slot.o
diff --git a/drivers/acpi/hotplug/acpihp.h b/drivers/acpi/hotplug/acpihp.h
index 7c49eab..54d9d95 100644
--- a/drivers/acpi/hotplug/acpihp.h
+++ b/drivers/acpi/hotplug/acpihp.h
@@ -26,6 +26,7 @@
#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_hotplug.h>
+#include "../internal.h"
extern struct acpi_device *acpi_root;
extern struct acpihp_slot_ops acpihp_slot_ej0;
diff --git a/drivers/acpi/hotplug/device.c b/drivers/acpi/hotplug/device.c
new file mode 100644
index 0000000..fb0451f
--- /dev/null
+++ b/drivers/acpi/hotplug/device.c
@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2012 Huawei Tech. Co., Ltd.
+ * 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; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/types.h>
+#include <linux/device.h>
+#include <acpi/acpi.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_hotplug.h>
+#include "acpihp.h"
+
+/*
+ * When creating ACPI devices for hot-added system devices connecting to slot,
+ * don't cross the slot boundary. Otherwise it will cause inconsistence
+ * to other hotplug slots.
+ */
+static acpi_status acpihp_filter_device(acpi_handle hdl, u32 level, void *arg)
+{
+ /* Skip if the handle corresponds to a child hotplug slot. */
+ if (level > 0 && acpihp_is_slot(hdl))
+ return AE_CTRL_DEPTH;
+
+ return AE_OK;
+}
+
+/* Create ACPI devices for hot-added system devices connecting to a slot. */
+int acpihp_add_devices(acpi_handle handle, struct acpi_device **child)
+{
+ struct acpi_bus_ops ops;
+
+ memset(&ops, 0, sizeof(ops));
+ ops.acpi_op_add = 1;
+ ops.acpi_op_filter_fn = &acpihp_filter_device;
+ ops.acpi_op_filter_arg = NULL;
+
+ return acpi_bus_scan(handle, &ops, child);
+}
+EXPORT_SYMBOL_GPL(acpihp_add_devices);
+
+struct acpihp_walk_arg {
+ acpihp_walk_device_cb cb;
+ void *arg;
+ acpi_status status;
+};
+
+static int acpihp_walk_cb(struct device *dev, void *data)
+{
+ acpi_status status;
+ struct acpihp_walk_arg *argp = (struct acpihp_walk_arg *)data;
+ struct acpi_device *acpi_dev;
+
+ if (dev->bus != &acpi_bus_type)
+ return 0;
+
+ /* Skip if the handle corresponds to a child hotplug slot. */
+ acpi_dev = container_of(dev, struct acpi_device, dev);
+ if (acpihp_is_slot(acpi_dev->handle))
+ return 0;
+
+ status = argp->cb(acpi_dev, argp->arg);
+ if (status == AE_OK) {
+ return device_for_each_child(dev, data, &acpihp_walk_cb);
+ } else if (status == AE_CTRL_DEPTH || status == AE_CTRL_SKIP) {
+ return 0;
+ } else {
+ argp->status = status;
+ return -1;
+ }
+}
+
+/*
+ * Walk all ACPI devices connecting to a hotplug slot, but don't cross the
+ * hotplug slot boundary.
+ */
+int acpihp_walk_devices(acpi_handle handle, acpihp_walk_device_cb cb,
+ void *argp)
+{
+ acpi_status status;
+ struct acpi_device *device;
+ struct acpihp_walk_arg arg;
+
+ if (acpi_bus_get_device(handle, &device))
+ return -ENODEV;
+
+ status = (*cb)(device, argp);
+ if (ACPI_SUCCESS(status)) {
+ arg.cb = cb;
+ arg.arg = argp;
+ arg.status = AE_OK;
+ (void) device_for_each_child(&device->dev, &arg,
+ &acpihp_walk_cb);
+ status = arg.status;
+ }
+
+ if (status == AE_CTRL_DEPTH || status == AE_CTRL_TERMINATE ||
+ status == AE_CTRL_SKIP)
+ status = AE_OK;
+ else if (ACPI_FAILURE(status))
+ ACPIHP_DEBUG("fails to walk devices under %p.\n", handle);
+
+ acpi_device_put(device);
+
+ return status == AE_OK ? 0 : -ENODEV;
+}
+EXPORT_SYMBOL_GPL(acpihp_walk_devices);
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 70843c0..6f0632d 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -95,5 +95,7 @@ static inline void suspend_nvs_restore(void) {}
extern struct rw_semaphore acpi_device_data_handler_sem;
void acpi_bus_data_handler(acpi_handle handle, void *context);
+int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops,
+ struct acpi_device **child);
#endif /* _ACPI_INTERNAL_H_ */
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index a1d5188..028294d 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1431,6 +1431,14 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
return AE_CTRL_DEPTH;
}
+ /* Hooks for ACPI based system device hotplug */
+ if (ops->acpi_op_filter_fn != NULL) {
+ result = ops->acpi_op_filter_fn(handle, lvl,
+ ops->acpi_op_filter_arg);
+ if (result != AE_OK)
+ return result;
+ }
+
/*
* We may already have an acpi_device from a previous enumeration. If
* so, we needn't add it again, but we may still have to start it.
@@ -1454,7 +1462,7 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
return AE_OK;
}
-static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops,
+int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops,
struct acpi_device **child)
{
acpi_status status;
@@ -1612,6 +1620,7 @@ int __init acpi_scan_init(void)
memset(&ops, 0, sizeof(ops));
ops.acpi_op_add = 1;
ops.acpi_op_start = 1;
+ ops.acpi_op_filter_fn = NULL;
result = bus_register(&acpi_bus_type);
if (result) {
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 0a109fc..8136dd7 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -127,6 +127,8 @@ typedef void (*acpi_op_notify) (struct acpi_device * device, u32 event);
struct acpi_bus_ops {
u32 acpi_op_add:1;
u32 acpi_op_start:1;
+ acpi_status (*acpi_op_filter_fn)(acpi_handle, u32, void *);
+ void *acpi_op_filter_arg;
};
struct acpi_device_ops {
diff --git a/include/acpi/acpi_hotplug.h b/include/acpi/acpi_hotplug.h
index 0b61a10..5025a16 100644
--- a/include/acpi/acpi_hotplug.h
+++ b/include/acpi/acpi_hotplug.h
@@ -175,6 +175,21 @@ extern acpi_status acpihp_slot_get_status(struct acpihp_slot *slot,
extern acpi_status acpihp_slot_poweron(struct acpihp_slot *slot);
extern acpi_status acpihp_slot_poweroff(struct acpihp_slot *slot);
+/*
+ * Add device objects for ACPI devices connecting to an ACPI hotplug slot,
+ * but don't cross the hotplug slot boundary.
+ */
+extern int acpihp_add_devices(acpi_handle handle, struct acpi_device **child);
+
+/*
+ * Walk all ACPI devices connecting to an ACPI hotplug slot,
+ * but don't cross the hotplug slot boundary.
+ */
+typedef acpi_status (*acpihp_walk_device_cb)(struct acpi_device *acpi_device,
+ void *argp);
+extern int acpihp_walk_devices(acpi_handle handle, acpihp_walk_device_cb cb,
+ void *argp);
+
extern int acpihp_debug;
#define ACPIHP_WARN(fmt, ...) \
--
1.7.9.5
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