@@ -15,3 +15,4 @@ acpihp_drv-y = drv_main.o
acpihp_drv-y += dependency.o
acpihp_drv-y += cancel.o
acpihp_drv-y += configure.o
+acpihp_drv-y += state_machine.o
@@ -49,6 +49,7 @@ enum acpihp_drv_cancel_state {
struct acpihp_slot_drv {
struct mutex op_mutex;
+ struct list_head depend_list;
atomic_t cancel_state;
atomic_t cancel_users;
struct acpihp_cancel_context cancel_ctx;
@@ -61,6 +62,9 @@ struct acpihp_slot_dependency {
u32 execute_stages;
};
+extern struct mutex state_machine_mutex;
+extern wait_queue_head_t acpihp_drv_event_wq;
+
void acpihp_drv_get_data(struct acpihp_slot *slot,
struct acpihp_slot_drv **data);
int acpihp_drv_enumerate_devices(struct acpihp_slot *slot);
@@ -85,4 +89,7 @@ int acpihp_drv_cancel_wait(struct list_head *list);
int acpihp_drv_configure(struct list_head *list);
int acpihp_drv_unconfigure(struct list_head *list);
+/* The heart of the ACPI system device hotplug driver */
+int acpihp_drv_change_state(struct acpihp_slot *slot, enum acpihp_drv_cmd cmd);
+
#endif /* __ACPIHP_DRV_H__ */
@@ -273,6 +273,7 @@ static int acpihp_drv_slot_add(struct device *dev, struct class_interface *intf)
drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
if (drv_data) {
mutex_init(&drv_data->op_mutex);
+ INIT_LIST_HEAD(&drv_data->depend_list);
}
if (drv_data == NULL ||
acpihp_slot_attach_drv_data(slot, intf, (void *)drv_data)) {
new file mode 100644
@@ -0,0 +1,639 @@
+/*
+ * Copyright (C) 2012 Huawei Tech. Co., Ltd.
+ * Copyright (C) 2012 Jiang Liu <jiang.liu@huawei.com>
+ * Copyright (C) 2012 Hanjun Guo <guohanjun@huawei.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * 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/mutex.h>
+#include <linux/wait.h>
+#include <acpi/acpi_hotplug.h>
+#include "acpihp_drv.h"
+
+/*
+ * Global lock to serialize manipulating of dependency list among hotplug slots
+ * to avoid deadlock among slots. The lock order is:
+ * 1) acquire state_machine_mutex
+ * 2) acquire drv_data->op_mutex
+ * 3) acquire slot's device lock
+ */
+DEFINE_MUTEX(state_machine_mutex);
+DECLARE_WAIT_QUEUE_HEAD(acpihp_drv_event_wq);
+
+static int acpihp_drv_lock_slot(struct acpihp_slot *slot)
+{
+ int retval = 0;
+ struct acpihp_slot_drv *drv_data;
+
+ acpihp_drv_get_data(slot, &drv_data);
+ if (!mutex_trylock(&drv_data->op_mutex)) {
+ ACPIHP_SLOT_DEBUG(slot, "slot is busy in state %d.\n",
+ slot->state);
+ retval = -EBUSY;
+ }
+
+ return retval;
+}
+
+static void acpihp_drv_unlock_slot(struct acpihp_slot *slot)
+{
+ struct acpihp_slot_drv *drv_data;
+
+ acpihp_drv_get_data(slot, &drv_data);
+ BUG_ON(!mutex_is_locked(&drv_data->op_mutex));
+ mutex_unlock(&drv_data->op_mutex);
+}
+
+/*
+ * Lock all slots in the dependency list to serialize concurrent operations.
+ * Caller must hold state_machine_mutex.
+ */
+static int acpihp_drv_lock_slots(struct list_head *list,
+ struct acpihp_slot *slot)
+{
+ struct acpihp_slot_dependency *dep;
+
+ list_for_each_entry(dep, list, node)
+ if (acpihp_drv_lock_slot(dep->slot))
+ goto unlock;
+
+ return 0;
+
+unlock:
+ list_for_each_entry_continue_reverse(dep, list, node)
+ acpihp_drv_unlock_slot(dep->slot);
+
+ return -EBUSY;
+}
+
+static void acpihp_drv_unlock_slots(struct list_head *list)
+{
+ struct acpihp_slot_dependency *dep;
+
+ list_for_each_entry(dep, list, node)
+ acpihp_drv_unlock_slot(dep->slot);
+}
+
+static bool acpihp_drv_is_ancestor(struct acpihp_slot *ancestor,
+ struct acpihp_slot *slot)
+{
+ while (slot) {
+ if (slot->parent == ancestor)
+ return true;
+ slot = slot->parent;
+ };
+
+ return false;
+}
+
+/*
+ * Check whether the command is valid according to current slot state,
+ * and get required operations for this slot if command is valid.
+ */
+static int acpihp_drv_validate_transition(struct acpihp_slot_dependency *dep,
+ struct acpihp_slot *target,
+ enum acpihp_drv_cmd cmd)
+{
+ u32 op1, op2;
+ struct acpihp_slot *slot = dep->slot;
+
+ if (slot->state <= ACPIHP_SLOT_STATE_UNKNOWN ||
+ slot->state >= ACPIHP_SLOT_STATE_MAX) {
+ ACPIHP_SLOT_DEBUG(slot, "invalid state %d.\n", slot->state);
+ return -EINVAL;
+ } else if (slot->state >= ACPIHP_SLOT_STATE_POWERING_ON) {
+ /*
+ * It shouldn't happen, transcendant states are protected
+ * by slot->op_mutex.
+ */
+ BUG_ON(slot->state);
+ return -EINVAL;
+ }
+
+ op1 = op2 = ACPIHP_DRV_CMD_NOOP;
+ dep->opcodes = ACPIHP_DRV_CMD_NOOP;
+
+ /*
+ * To be compatible with legacy OSes, the PCI host bridges built into
+ * physical processor may be hosted directly under \\__SB instead of
+ * under the CONTAINER device corresponding to physical processor.
+ * That's really a corner case to deal with.
+ */
+ switch (cmd) {
+ case ACPIHP_DRV_CMD_POWERON:
+ if (slot->state == ACPIHP_SLOT_STATE_ABSENT)
+ return -ENODEV;
+ else if (slot->state == ACPIHP_SLOT_STATE_PRESENT)
+ dep->opcodes = ACPIHP_DRV_CMD_POWERON;
+ break;
+
+ case ACPIHP_DRV_CMD_CONNECT:
+ /*
+ * Its parent must have already been connected when connecting
+ * a slot, otherwise the device tree topology becomes incorrect.
+ */
+ if (target == slot || acpihp_drv_is_ancestor(slot, target))
+ op2 = ACPIHP_DRV_CMD_CONNECT;
+
+ if (slot->state == ACPIHP_SLOT_STATE_ABSENT)
+ return -ENODEV;
+ else if (slot->state == ACPIHP_SLOT_STATE_PRESENT)
+ dep->opcodes = ACPIHP_DRV_CMD_POWERON | op2;
+ else if (slot->state == ACPIHP_SLOT_STATE_POWERED)
+ dep->opcodes = op2;
+ break;
+
+ case ACPIHP_DRV_CMD_CONFIGURE:
+ /* Only CONFIGURE the requested slot */
+ if (slot == target)
+ op1 = ACPIHP_DRV_CMD_CONFIGURE;
+ /*
+ * Its parent must have already been connected when configuring
+ * a slot, otherwise the device tree topology becomes incorrect.
+ */
+ if (target == slot || acpihp_drv_is_ancestor(slot, target))
+ op2 = ACPIHP_DRV_CMD_CONNECT;
+
+ if (slot->state == ACPIHP_SLOT_STATE_ABSENT)
+ return -ENODEV;
+ else if (slot->state == ACPIHP_SLOT_STATE_PRESENT)
+ dep->opcodes = ACPIHP_DRV_CMD_POWERON | op1 | op2;
+ else if (slot->state == ACPIHP_SLOT_STATE_POWERED)
+ dep->opcodes = op1 | op2;
+ else if (slot->state == ACPIHP_SLOT_STATE_CONNECTED)
+ dep->opcodes = op1;
+ break;
+
+ case ACPIHP_DRV_CMD_UNCONFIGURE:
+ /* Only UNCONFIGURE the requested slot */
+ if (slot->state == ACPIHP_SLOT_STATE_CONFIGURED &&
+ slot == target)
+ dep->opcodes = ACPIHP_DRV_CMD_UNCONFIGURE;
+ break;
+
+ case ACPIHP_DRV_CMD_DISCONNECT:
+ /*
+ * all descedant slots must be unconfigured/disconnected
+ * when disconnecting a slot.
+ */
+ if (target == slot || acpihp_drv_is_ancestor(target, slot)) {
+ op1 = ACPIHP_DRV_CMD_UNCONFIGURE;
+ op2 = ACPIHP_DRV_CMD_DISCONNECT;
+ }
+
+ if (slot->state == ACPIHP_SLOT_STATE_CONFIGURED)
+ dep->opcodes = op1 | op2;
+ else if (slot->state == ACPIHP_SLOT_STATE_CONNECTED)
+ dep->opcodes = op2;
+ break;
+
+ case ACPIHP_DRV_CMD_POWEROFF:
+ /*
+ * All slots have dependency on the target slot must be
+ * powered off when powering the target slot off.
+ */
+ if (slot->state == ACPIHP_SLOT_STATE_CONFIGURED)
+ dep->opcodes = ACPIHP_DRV_CMD_UNCONFIGURE |
+ ACPIHP_DRV_CMD_DISCONNECT |
+ ACPIHP_DRV_CMD_POWEROFF;
+ else if (slot->state == ACPIHP_SLOT_STATE_CONNECTED)
+ dep->opcodes = ACPIHP_DRV_CMD_DISCONNECT |
+ ACPIHP_DRV_CMD_POWEROFF;
+ else if (slot->state == ACPIHP_SLOT_STATE_POWERED)
+ dep->opcodes = ACPIHP_DRV_CMD_POWEROFF;
+ break;
+
+ default:
+ ACPIHP_SLOT_DEBUG(slot, "invalid command %d.\n", cmd);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int acpihp_drv_validate_command(struct list_head *list,
+ struct acpihp_slot *target, enum acpihp_drv_cmd cmd)
+{
+ int retval;
+ struct acpihp_slot *slot;
+ struct acpihp_slot_dependency *dep;
+
+ list_for_each_entry(dep, list, node) {
+ slot = dep->slot;
+ acpihp_drv_update_slot_status(slot);
+
+ retval = acpihp_drv_validate_transition(dep, target, cmd);
+ if (retval) {
+ ACPIHP_SLOT_DEBUG(slot,
+ "invalid transition for slot in state %d.\n",
+ slot->state);
+ return retval;
+ }
+
+ /* Check whether the slot is in good shape */
+ if (dep->opcodes &&
+ acpihp_slot_get_flag(slot, ACPIHP_SLOT_FLAG_FAULT)) {
+ ACPIHP_SLOT_WARN(slot,
+ "slot has been marked as faulty.\n");
+ return -EINVAL;
+ } else if ((dep->opcodes & ACPIHP_DRV_CMD_UNCONFIGURE) &&
+ acpihp_slot_get_flag(slot, ACPIHP_SLOT_FLAG_IRREMOVABLE)) {
+ ACPIHP_SLOT_WARN(slot, "slot is busy.\n");
+ return -EBUSY;
+ }
+ }
+
+ return 0;
+}
+
+static int acpihp_drv_pre_execute(struct acpihp_slot *slot,
+ enum acpihp_drv_cmd cmd,
+ struct list_head **head)
+{
+ int retval;
+ struct list_head *list;
+ struct acpihp_slot_drv *drv_data;
+
+ acpihp_drv_get_data(slot, &drv_data);
+ mutex_lock(&state_machine_mutex);
+ *head = list = &drv_data->depend_list;
+
+ /*
+ * Set cancellation flags on all affected slots.
+ * All affected slots should already be on drv_data->depend_list
+ * if there's inprogress operation for the slot.
+ *
+ * state_machine_mutex must be held to serialize calls to
+ * acpihp_drv_cancel_init(),
+ * acpihp_drv_cancel_start(),
+ * acpihp_drv_cancel_fini(),
+ */
+ if (cmd == ACPIHP_DRV_CMD_CANCEL) {
+ retval = acpihp_drv_cancel_start(list);
+ goto out;
+ }
+
+ /* bail out if slot has already been locked to avoid deadlock */
+ if (mutex_is_locked(&drv_data->op_mutex)) {
+ ACPIHP_SLOT_DEBUG(slot, "is busy.\n");
+ retval = -EBUSY;
+ goto out;
+ }
+
+ BUG_ON(!list_empty(list));
+ retval = acpihp_drv_generate_dependency_list(slot, list, cmd);
+ if (retval) {
+ ACPIHP_SLOT_DEBUG(slot, "fails to get dependency lists.\n");
+ goto out;
+ }
+
+ retval = acpihp_drv_lock_slots(list, slot);
+ if (retval) {
+ ACPIHP_SLOT_DEBUG(slot, "fails to lock slots.\n");
+ acpihp_drv_destroy_dependency_list(list);
+ goto out;
+ }
+
+ retval = acpihp_drv_validate_command(list, slot, cmd);
+ if (retval) {
+ ACPIHP_SLOT_DEBUG(slot, "invalid command.\n");
+ acpihp_drv_unlock_slots(list);
+ acpihp_drv_destroy_dependency_list(list);
+ } else {
+ acpihp_drv_cancel_init(list);
+ }
+
+out:
+ mutex_unlock(&state_machine_mutex);
+
+ return retval;
+}
+
+static void acpihp_drv_post_execute(struct list_head *list,
+ enum acpihp_drv_cmd cmd)
+{
+ if (cmd == ACPIHP_DRV_CMD_CANCEL)
+ return;
+
+ mutex_lock(&state_machine_mutex);
+ if (list && !list_empty(list)) {
+ acpihp_drv_cancel_fini(list);
+ acpihp_drv_unlock_slots(list);
+ acpihp_drv_destroy_dependency_list(list);
+ }
+ mutex_unlock(&state_machine_mutex);
+}
+
+static int acpihp_drv_poweron_slot(struct acpihp_slot *slot)
+{
+ acpi_status status;
+ struct acpihp_slot_drv *drv_data;
+
+ if (acpihp_slot_powered(slot))
+ return 0;
+
+ acpihp_drv_get_data(slot, &drv_data);
+
+ status = acpihp_slot_poweron(slot);
+ if (ACPI_FAILURE(status)) {
+ if (status == AE_SUPPORT)
+ return -ENOSYS;
+ else {
+ ACPIHP_SLOT_WARN(slot, "fails to power on slot.\n");
+ acpihp_slot_set_flag(slot, ACPIHP_SLOT_FLAG_FAULT);
+ return -ENXIO;
+ }
+ }
+
+ if (!acpihp_slot_powered(slot)) {
+ ACPIHP_SLOT_WARN(slot, "fails to power on.\n");
+ acpihp_slot_set_flag(slot, ACPIHP_SLOT_FLAG_FAULT);
+ return -ENXIO;
+ }
+
+ return 0;
+}
+
+static int acpihp_drv_poweron(struct list_head *list)
+{
+ int retval = 0;
+ struct acpihp_slot_dependency *dep;
+
+ list_for_each_entry(dep, list, node) {
+ if (!(dep->opcodes & ACPIHP_DRV_CMD_POWERON))
+ continue;
+
+ acpihp_slot_change_state(dep->slot,
+ ACPIHP_SLOT_STATE_POWERING_ON);
+ retval = acpihp_drv_poweron_slot(dep->slot);
+ if (!retval) {
+ ACPIHP_SLOT_DEBUG(dep->slot, "succeed to power on!\n");
+ acpihp_slot_change_state(dep->slot,
+ ACPIHP_SLOT_STATE_POWERED);
+ } else {
+ acpihp_slot_change_state(dep->slot,
+ ACPIHP_SLOT_STATE_PRESENT);
+ break;
+ }
+ }
+
+ return retval;
+}
+
+static int acpihp_drv_poweroff_slot(struct acpihp_slot *slot)
+{
+ acpi_status status;
+
+ if (acpihp_slot_powered(slot))
+ return 0;
+
+ status = acpihp_slot_poweroff(slot);
+ if (ACPI_FAILURE(status)) {
+ if (status == AE_SUPPORT)
+ return -ENOSYS;
+ else {
+ ACPIHP_SLOT_WARN(slot, "fails to power off slot.\n");
+ acpihp_slot_set_flag(slot, ACPIHP_SLOT_FLAG_FAULT);
+ return -ENXIO;
+ }
+ }
+
+ if (acpihp_slot_powered(slot)) {
+ ACPIHP_SLOT_WARN(slot, "fails to power off slot.\n");
+ acpihp_slot_set_flag(slot, ACPIHP_SLOT_FLAG_FAULT);
+ return -ENXIO;
+ }
+
+ return 0;
+}
+
+static int acpihp_drv_poweroff(struct list_head *list)
+{
+ int retval = 0;
+ struct acpihp_slot_dependency *dep;
+
+ list_for_each_entry(dep, list, node) {
+ if (!(dep->opcodes & ACPIHP_DRV_CMD_POWEROFF))
+ continue;
+
+ acpihp_slot_change_state(dep->slot,
+ ACPIHP_SLOT_STATE_POWERING_OFF);
+ retval = acpihp_drv_poweroff_slot(dep->slot);
+ if (!retval) {
+ ACPIHP_SLOT_DEBUG(dep->slot,
+ "succeed to power off slot!\n");
+ acpihp_slot_change_state(dep->slot,
+ ACPIHP_SLOT_STATE_PRESENT);
+ } else {
+ acpihp_slot_change_state(dep->slot,
+ ACPIHP_SLOT_STATE_POWERED);
+ break;
+ }
+ }
+
+ return retval;
+}
+
+static int acpihp_drv_connect_slot(struct acpihp_slot *slot)
+{
+ int retval;
+
+ retval = acpihp_add_devices(slot->handle, NULL);
+ if (retval)
+ ACPIHP_SLOT_DEBUG(slot,
+ "fails to add ACPI devices for slot.\n");
+ else {
+ retval = acpihp_drv_enumerate_devices(slot);
+ if (retval)
+ ACPIHP_SLOT_DEBUG(slot,
+ "fails to enumerate device for slot.\n");
+ }
+
+ return retval;
+}
+
+static int acpihp_drv_connect(struct list_head *list)
+{
+ int retval = 0;
+ struct acpihp_slot_dependency *dep;
+
+ list_for_each_entry(dep, list, node) {
+ if (!(dep->opcodes & ACPIHP_DRV_CMD_CONNECT))
+ continue;
+
+ acpihp_slot_change_state(dep->slot,
+ ACPIHP_SLOT_STATE_CONNECTING);
+ retval = acpihp_drv_connect_slot(dep->slot);
+ if (!retval) {
+ ACPIHP_SLOT_DEBUG(dep->slot,
+ "succeed to connect slot!\n");
+ acpihp_slot_change_state(dep->slot,
+ ACPIHP_SLOT_STATE_CONNECTED);
+ } else {
+ acpihp_slot_set_flag(dep->slot, ACPIHP_SLOT_FLAG_FAULT);
+ acpihp_drv_update_slot_state(dep->slot);
+ break;
+ }
+ }
+
+ return retval;
+}
+
+static int acpihp_drv_disconnect_slot(struct acpihp_slot *slot)
+{
+ int retval = 0;
+ enum acpihp_dev_type i;
+ struct acpi_device *device = NULL;
+
+ /* remove all devices attached to a slot */
+ for (i = ACPIHP_DEV_TYPE_UNKNOWN; i < ACPIHP_DEV_TYPE_MAX; i++) {
+ retval = acpihp_remove_device_list(&slot->dev_lists[i]);
+ if (retval) {
+ ACPIHP_SLOT_DEBUG(slot,
+ "fails to remove ACPI devices.\n");
+ return retval;
+ }
+ }
+
+ /* remove ACPI devices */
+ retval = acpi_bus_get_device(slot->handle, &device);
+ if (!retval && device) {
+ retval = acpi_bus_trim(device, 1);
+ if (retval)
+ ACPIHP_SLOT_WARN(slot,
+ "fails to remove ACPI devices.\n");
+ } else {
+ ACPIHP_SLOT_WARN(slot, "fails to get ACPI device for slot.\n");
+ retval = -ENXIO;
+ }
+
+ return retval;
+}
+
+static int acpihp_drv_disconnect(struct list_head *list)
+{
+ int retval = 0;
+ struct acpihp_slot_dependency *dep;
+
+ list_for_each_entry(dep, list, node) {
+ if (!(dep->opcodes & ACPIHP_DRV_CMD_DISCONNECT))
+ continue;
+
+ acpihp_slot_change_state(dep->slot,
+ ACPIHP_SLOT_STATE_DISCONNECTING);
+ retval = acpihp_drv_disconnect_slot(dep->slot);
+ if (!retval) {
+ ACPIHP_SLOT_DEBUG(dep->slot,
+ "succeed to disconnect slot!\n");
+ acpihp_slot_change_state(dep->slot,
+ ACPIHP_SLOT_STATE_POWERED);
+ } else {
+ acpihp_slot_set_flag(dep->slot, ACPIHP_SLOT_FLAG_FAULT);
+ acpihp_drv_update_slot_state(dep->slot);
+ break;
+ }
+ }
+
+ return retval;
+}
+
+static int acpihp_drv_execute(struct list_head *list, enum acpihp_drv_cmd cmd)
+{
+ int retval = 0;
+ bool connect = false, configure = false;
+ bool disconnect = false, poweroff = false;
+
+ if (!list || list_empty(list)) {
+ ACPIHP_DEBUG("slot dependency list is NULL or empty!\n");
+ retval = -EINVAL;
+ goto out;
+ }
+
+ switch (cmd) {
+ case ACPIHP_DRV_CMD_CONFIGURE:
+ configure = true;
+ /* fall through */
+ case ACPIHP_DRV_CMD_CONNECT:
+ connect = true;
+ /* fall through */
+ case ACPIHP_DRV_CMD_POWERON:
+ retval = acpihp_drv_poweron(list);
+ if (!retval && connect)
+ retval = acpihp_drv_connect(list);
+ if (!retval && configure)
+ retval = acpihp_drv_configure(list);
+ break;
+
+ case ACPIHP_DRV_CMD_POWEROFF:
+ poweroff = true;
+ /* fall through */
+ case ACPIHP_DRV_CMD_DISCONNECT:
+ disconnect = true;
+ /* fall through */
+ case ACPIHP_DRV_CMD_UNCONFIGURE:
+ retval = acpihp_drv_unconfigure(list);
+ if (!retval && disconnect)
+ retval = acpihp_drv_disconnect(list);
+ if (!retval && poweroff)
+ retval = acpihp_drv_poweroff(list);
+ break;
+
+ case ACPIHP_DRV_CMD_CANCEL:
+ retval = acpihp_drv_cancel_wait(list);
+ break;
+
+ default:
+ ACPIHP_DEBUG("unsupported command %d.\n", cmd);
+ retval = -EINVAL;
+ break;
+ }
+
+out:
+ return retval;
+}
+
+/*
+ * The heart of ACPI based system device hotplug driver, which implements
+ * a state machine as below for hotplug slots.
+ *
+ * (plug in) (power on) (connect) (configure)
+ * [ABSENT] <-> [PRESENT] <-> [POWERED] <-> [CONNECTED] <-> [CONFIGURED]
+ * (plug out) (power off) (disconnect) (unconfigure)
+ *
+ * [...]: state
+ * (...): action
+ * (connect): create ACPI devices and bind ACPI device drivers
+ * (disconnect): unbind ACPI device drivers and destroy ACPI devices
+ * (configure): allocate resources and add system device into running system
+ * (unconfigure): remove system device from running system and free resources
+ */
+int acpihp_drv_change_state(struct acpihp_slot *slot, enum acpihp_drv_cmd cmd)
+{
+ int retval;
+ struct list_head *list = NULL;
+
+ retval = acpihp_drv_pre_execute(slot, cmd, &list);
+ if (!retval) {
+ retval = acpihp_drv_execute(list, cmd);
+ acpihp_drv_post_execute(list, cmd);
+ }
+
+ return retval;
+}
This patch implements the core of the new ACPI hotplug framework, a state machine for ACPI hotplug slots. The state machine is: (plug in) (power on) (connect) (configure) [ABSENT] <-> [PRESENT] <-> [POWERED] <-> [CONNECTED] <-> [CONFIGURED] (plug out) (power off) (disconnect) (unconfigure) [...]: state (...): action (connect): create ACPI devices and bind ACPI device drivers (disconnect): unbind ACPI device drivers and destroy ACPI devices (configure): allocate resources and add system device into running system (unconfigure): remove system device from running system and free resources It provides a simple interface to drive the state machine: int acpihp_drv_change_state(struct acpihp_slot *slot, enum acpihp_drv_cmd cmd); It glues all hotplug logic together, including resolving dependencies among slots, cancalling inprogress hotplug operations and configuring/ unconfigure system devices etc. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Hanjun Guo <guohanjun@huawei.com> --- drivers/acpi/hotplug/Makefile | 1 + drivers/acpi/hotplug/acpihp_drv.h | 7 + drivers/acpi/hotplug/drv_main.c | 1 + drivers/acpi/hotplug/state_machine.c | 639 ++++++++++++++++++++++++++++++++++ 4 files changed, 648 insertions(+) create mode 100644 drivers/acpi/hotplug/state_machine.c