Re: [Update][PATCH 4/6] ACPI / hotplug: Simplify device ejection routines

From: Rafael J. Wysocki
Date: Wed Nov 06 2013 - 19:02:43 EST


On Wednesday, November 06, 2013 04:27:01 PM Toshi Kani wrote:
> On Mon, 2013-11-04 at 14:36 +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> >
> > Simplify handle_root_bridge_removal() and acpi_eject_store() by
> > getting rid of struct acpi_eject_event and passing device objects
> > directly to async routines executed via acpi_os_hotplug_execute().
> :
> > static ssize_t
> > acpi_eject_store(struct device *d, struct device_attribute *attr,
> > const char *buf, size_t count)
> > {
> > struct acpi_device *acpi_device = to_acpi_device(d);
> > - struct acpi_eject_event *ej_event;
> > acpi_object_type not_used;
> > acpi_status status;
> > - int ret;
> >
> > if (!count || buf[0] != '1')
> > return -EINVAL;
> > @@ -518,28 +519,17 @@ acpi_eject_store(struct device *d, struc
> > if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
> > return -ENODEV;
> >
> > - ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
> > - if (!ej_event) {
> > - ret = -ENOMEM;
> > - goto err_out;
> > - }
> > acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
> > ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
> > - ej_event->device = acpi_device;
> > - ej_event->event = ACPI_OST_EC_OSPM_EJECT;
> > get_device(&acpi_device->dev);
> > - status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
> > + status = acpi_os_hotplug_execute(acpi_eject_store_work, acpi_device);
> > if (ACPI_SUCCESS(status))
> > return count;
> >
> > put_device(&acpi_device->dev);
> > - kfree(ej_event);
> > - ret = status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
>
> Why are you deleting the above line as part of this change?

Ah, because I forgot that acpi_os_hotplug_execute() can also return AE_NO_MEMORY. :-)

Good catch, updated pach follows.

Thanks,
Rafael

---
From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Subject: ACPI / hotplug: Simplify device ejection routines

Simplify handle_root_bridge_removal() and acpi_eject_store() by
getting rid of struct acpi_eject_event and passing device objects
directly to async routines executed via acpi_os_hotplug_execute().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/pci_root.c | 20 ++------------------
drivers/acpi/scan.c | 46 ++++++++++++++++++----------------------------
include/acpi/acpi_bus.h | 5 -----
3 files changed, 20 insertions(+), 51 deletions(-)

Index: linux-pm/drivers/acpi/pci_root.c
===================================================================
--- linux-pm.orig/drivers/acpi/pci_root.c
+++ linux-pm/drivers/acpi/pci_root.c
@@ -593,27 +593,11 @@ static void handle_root_bridge_insertion
static void handle_root_bridge_removal(struct acpi_device *device)
{
acpi_status status;
- struct acpi_eject_event *ej_event;
-
- ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
- if (!ej_event) {
- /* Inform firmware the hot-remove operation has error */
- (void) acpi_evaluate_hotplug_ost(device->handle,
- ACPI_NOTIFY_EJECT_REQUEST,
- ACPI_OST_SC_NON_SPECIFIC_FAILURE,
- NULL);
- return;
- }
-
- ej_event->device = device;
- ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;

get_device(&device->dev);
- status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
- if (ACPI_FAILURE(status)) {
+ status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, device);
+ if (ACPI_FAILURE(status))
put_device(&device->dev);
- kfree(ej_event);
- }
}

static void _handle_hotplug_event_root(struct work_struct *work)
Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -441,18 +441,8 @@ static void acpi_hotplug_notify_cb(acpi_
NULL);
}

-/**
- * acpi_bus_hot_remove_device: hot-remove a device and its children
- * @context: struct acpi_eject_event pointer (freed in this func)
- *
- * Hot-remove a device and its children. This function frees up the
- * memory space passed by arg context, so that the caller may call
- * this function asynchronously through acpi_os_hotplug_execute().
- */
-void acpi_bus_hot_remove_device(void *context)
+void __acpi_bus_hot_remove_device(struct acpi_device *device, u32 ost_src)
{
- struct acpi_eject_event *ej_event = context;
- struct acpi_device *device = ej_event->device;
acpi_handle handle = device->handle;
int error;

@@ -461,13 +451,21 @@ void acpi_bus_hot_remove_device(void *co

error = acpi_scan_hot_remove(device);
if (error && handle)
- acpi_evaluate_hotplug_ost(handle, ej_event->event,
+ acpi_evaluate_hotplug_ost(handle, ost_src,
ACPI_OST_SC_NON_SPECIFIC_FAILURE,
NULL);

mutex_unlock(&acpi_scan_lock);
unlock_device_hotplug();
- kfree(context);
+}
+
+/**
+ * acpi_bus_hot_remove_device: Hot-remove a device and its children.
+ * @context: Address of the ACPI device object to hot-remove.
+ */
+void acpi_bus_hot_remove_device(void *context)
+{
+ __acpi_bus_hot_remove_device(context, ACPI_NOTIFY_EJECT_REQUEST);
}
EXPORT_SYMBOL(acpi_bus_hot_remove_device);

@@ -497,15 +495,18 @@ static ssize_t power_state_show(struct d

static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);

+static void acpi_eject_store_work(void *context)
+{
+ __acpi_bus_hot_remove_device(context, ACPI_OST_EC_OSPM_EJECT);
+}
+
static ssize_t
acpi_eject_store(struct device *d, struct device_attribute *attr,
const char *buf, size_t count)
{
struct acpi_device *acpi_device = to_acpi_device(d);
- struct acpi_eject_event *ej_event;
acpi_object_type not_used;
acpi_status status;
- int ret;

if (!count || buf[0] != '1')
return -EINVAL;
@@ -518,28 +519,17 @@ acpi_eject_store(struct device *d, struc
if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
return -ENODEV;

- ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
- if (!ej_event) {
- ret = -ENOMEM;
- goto err_out;
- }
acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
- ej_event->device = acpi_device;
- ej_event->event = ACPI_OST_EC_OSPM_EJECT;
get_device(&acpi_device->dev);
- status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
+ status = acpi_os_hotplug_execute(acpi_eject_store_work, acpi_device);
if (ACPI_SUCCESS(status))
return count;

put_device(&acpi_device->dev);
- kfree(ej_event);
- ret = status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
-
- err_out:
acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
- return ret;
+ return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
}

static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
Index: linux-pm/include/acpi/acpi_bus.h
===================================================================
--- linux-pm.orig/include/acpi/acpi_bus.h
+++ linux-pm/include/acpi/acpi_bus.h
@@ -339,11 +339,6 @@ struct acpi_bus_event {
u32 data;
};

-struct acpi_eject_event {
- struct acpi_device *device;
- u32 event;
-};
-
struct acpi_hp_work {
struct work_struct work;
acpi_handle handle;

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