From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Modify the common ACPI device hotplug code to always queue up the
same function, acpi_device_hotplug(), using acpi_hotplug_execute()
and make the PCI host bridge hotplug code use that function too for
device hot removal.
This allows some code duplication to be reduced and a race condition
where the relevant ACPI handle may become invalid between the
notification handler and the function queued up by it via
acpi_hotplug_execute() to be avoided.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/internal.h | 2
drivers/acpi/pci_root.c | 4 +
drivers/acpi/scan.c | 141 +++++++++++++++++++++---------------------------
3 files changed, 68 insertions(+), 79 deletions(-)
Index: linux-pm/drivers/acpi/internal.h
===================================================================
--- linux-pm.orig/drivers/acpi/internal.h
+++ linux-pm/drivers/acpi/internal.h
@@ -89,7 +89,7 @@ void acpi_device_add_finalize(struct acp
void acpi_free_pnp_ids(struct acpi_device_pnp *pnp);
int acpi_bind_one(struct device *dev, acpi_handle handle);
int acpi_unbind_one(struct device *dev);
-void acpi_bus_device_eject(void *data, u32 ost_src);
+void acpi_device_hotplug(void *data, u32 ost_src);
bool acpi_device_is_present(struct acpi_device *adev);
/* --------------------------------------------------------------------------
Index: linux-pm/drivers/acpi/pci_root.c
===================================================================
--- linux-pm.orig/drivers/acpi/pci_root.c
+++ linux-pm/drivers/acpi/pci_root.c
@@ -680,11 +680,13 @@ static void hotplug_event_root(void *dat
if (!root)
break;
+ acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
+ ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
get_device(&root->device->dev);
acpi_scan_lock_release();
- acpi_bus_device_eject(root->device, ACPI_NOTIFY_EJECT_REQUEST);
+ acpi_device_hotplug(root->device, ACPI_NOTIFY_EJECT_REQUEST);
return;
default:
acpi_handle_warn(handle,
Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -206,12 +206,8 @@ static int acpi_scan_hot_remove(struct a
acpi_status status;
unsigned long long sta;
- /* If there is no handle, the device node has been unregistered. */
- if (!handle) {
- dev_dbg(&device->dev, "ACPI handle missing\n");
- put_device(&device->dev);
- return -EINVAL;
- }
+ if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
+ kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
/*
* Carry out two passes here and ignore errors in the first pass,
@@ -230,7 +226,6 @@ static int acpi_scan_hot_remove(struct a
dev_warn(errdev, "Offline disabled.\n");
acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
acpi_bus_online, NULL, NULL, NULL);
- put_device(&device->dev);
return -EPERM;
}
acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
@@ -249,7 +244,6 @@ static int acpi_scan_hot_remove(struct a
acpi_walk_namespace(ACPI_TYPE_ANY, handle,
ACPI_UINT32_MAX, acpi_bus_online,
NULL, NULL, NULL);
- put_device(&device->dev);
return -EBUSY;
}
}
@@ -259,9 +253,6 @@ static int acpi_scan_hot_remove(struct a
acpi_bus_trim(device);
- put_device(&device->dev);
- device = NULL;
-
acpi_evaluate_lck(handle, 0);
/*
* TBD: _EJD support.
@@ -288,77 +279,74 @@ static int acpi_scan_hot_remove(struct a
return 0;
}
-void acpi_bus_device_eject(void *data, u32 ost_src)
+static int acpi_scan_device_check(struct acpi_device *adev)
{
- struct acpi_device *device = data;
- acpi_handle handle = device->handle;
- u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
int error;
- lock_device_hotplug();
- mutex_lock(&acpi_scan_lock);
-
- if (ost_src == ACPI_NOTIFY_EJECT_REQUEST)
- acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
- ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
-
- if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
- kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
-
- error = acpi_scan_hot_remove(device);
- if (error == -EPERM) {
- goto err_support;
- } else if (error) {
- goto err_out;
+ /*
+ * This function is only called for device objects for which matching
+ * scan handlers exist. The only situation in which the scan handler is
+ * not attached to this device object yet is when the device has just
+ * appeared (either it wasn't present at all before or it was removed
+ * and then added again).
+ */
+ if (adev->handler) {
+ dev_warn(&adev->dev, "Already enumerated\n");
+ return -EBUSY;
}
-
- out:
- mutex_unlock(&acpi_scan_lock);
- unlock_device_hotplug();
- return;
-
- err_support:
- ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
- err_out:
- acpi_evaluate_hotplug_ost(handle, ost_src, ost_code, NULL);
- goto out;
+ error = acpi_bus_scan(adev->handle);
+ if (error) {
+ dev_warn(&adev->dev, "Namespace scan failure\n");
+ return error;
+ }
+ if (adev->handler) {
+ if (adev->handler->hotplug.mode == AHM_CONTAINER)
+ kobject_uevent(&adev->dev.kobj, KOBJ_ONLINE);
+ } else {
+ dev_warn(&adev->dev, "Enumeration failure\n");
+ return -ENODEV;
+ }
+ return 0;
}
-static void acpi_scan_bus_device_check(void *data, u32 ost_source)
+void acpi_device_hotplug(void *data, u32 src)
{
- acpi_handle handle = data;
- struct acpi_device *device;
u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
+ struct acpi_device *adev = data;
int error;
lock_device_hotplug();
mutex_lock(&acpi_scan_lock);
- if (ost_source != ACPI_NOTIFY_BUS_CHECK) {
- device = NULL;
- acpi_bus_get_device(handle, &device);
- if (acpi_device_enumerated(device)) {
- dev_warn(&device->dev, "Attempt to re-insert\n");
- goto out;
- }
- }
- error = acpi_bus_scan(handle);
- if (error) {
- acpi_handle_warn(handle, "Namespace scan failure\n");
- goto out;
- }
- device = NULL;
- acpi_bus_get_device(handle, &device);
- if (!acpi_device_enumerated(device)) {
- acpi_handle_warn(handle, "Device not enumerated\n");
+ /*
+ * The device object's ACPI handle cannot become invalid as long as we
+ * are holding acpi_scan_lock, but it may have become invalid before
+ * that lock was acquired.
+ */
+ if (adev->handle == INVALID_ACPI_HANDLE)
goto out;
+
+ switch (src) {
+ case ACPI_NOTIFY_BUS_CHECK:
+ error = acpi_bus_scan(adev->handle);
+ break;
+ case ACPI_NOTIFY_DEVICE_CHECK:
+ error = acpi_scan_device_check(adev);
+ break;
+ case ACPI_NOTIFY_EJECT_REQUEST:
+ case ACPI_OST_EC_OSPM_EJECT:
+ error = acpi_scan_hot_remove(adev);
+ break;
+ default:
+ error = -EINVAL;
+ break;
}
- ost_code = ACPI_OST_SC_SUCCESS;
- if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
- kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
+ if (!error)
+ ost_code = ACPI_OST_SC_SUCCESS;
out:
- acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL);
+ acpi_evaluate_hotplug_ost(adev->handle, src, ost_code, NULL);
+ put_device(&adev->dev);
mutex_unlock(&acpi_scan_lock);
unlock_device_hotplug();
}
@@ -370,6 +358,9 @@ static void acpi_hotplug_notify_cb(acpi_
struct acpi_device *adev;
acpi_status status;
+ if (acpi_bus_get_device(handle, &adev))
+ goto err_out;
+
switch (type) {
case ACPI_NOTIFY_BUS_CHECK:
acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
@@ -384,24 +375,20 @@ static void acpi_hotplug_notify_cb(acpi_
ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
goto err_out;
}
- if (acpi_bus_get_device(handle, &adev))
- goto err_out;
-
- get_device(&adev->dev);
- status = acpi_hotplug_execute(acpi_bus_device_eject, adev, type);
- if (ACPI_SUCCESS(status))
- return;
-
- put_device(&adev->dev);
- goto err_out;
+ acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
+ ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
+ break;
default:
/* non-hotplug event; possibly handled by other handler */
return;
}
- status = acpi_hotplug_execute(acpi_scan_bus_device_check, handle, type);
+ get_device(&adev->dev);
+ status = acpi_hotplug_execute(acpi_device_hotplug, adev, type);
if (ACPI_SUCCESS(status))
return;
+ put_device(&adev->dev);
+
err_out:
acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
}
@@ -454,7 +441,7 @@ acpi_eject_store(struct device *d, struc
acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
get_device(&acpi_device->dev);
- status = acpi_hotplug_execute(acpi_bus_device_eject, acpi_device,
+ status = acpi_hotplug_execute(acpi_device_hotplug, acpi_device,
ACPI_OST_EC_OSPM_EJECT);
if (ACPI_SUCCESS(status))
return count;
--
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