On Tuesday, February 19, 2013 03:43:08 PM Yasuaki Ishimatsu wrote:
> Hi Rafael,
>
> I have comments. Please see below.
>
> 2013/02/18 0:21, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> >
> > Multiple drivers handling hotplug-capable ACPI device nodes install
> > notify handlers covering the same types of events in a very similar
> > way. Moreover, those handlers are installed in separate namespace
> > walks, although that really should be done during namespace scans
> > carried out by acpi_bus_scan(). This leads to substantial code
> > duplication, unnecessary overhead and behavior that is hard to
> > follow.
> >
> > For this reason, introduce common code in drivers/acpi/scan.c for
> > handling hotplug-related notification and carrying out device
> > insertion and eject operations in a generic fashion, such that it
> > may be used by all of the relevant drivers in the future. To cover
> > the existing differences between those drivers introduce struct
> > acpi_hotplug_profile for representing collections of hotplug
> > settings associated with different ACPI scan handlers that can be
> > used by the drivers to make the common code reflect their current
> > behavior.
> >
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> > ---
> > drivers/acpi/scan.c | 271 +++++++++++++++++++++++++++++++++++++-----------
> > include/acpi/acpi_bus.h | 7 +
> > 2 files changed, 220 insertions(+), 58 deletions(-)
> >
> > Index: test/include/acpi/acpi_bus.h
> > ===================================================================
> > --- test.orig/include/acpi/acpi_bus.h
> > +++ test/include/acpi/acpi_bus.h
> > @@ -88,11 +88,18 @@ struct acpi_device;
> > * -----------------
> > */
> >
> > +struct acpi_hotplug_profile {
> > + bool enabled:1;
> > + bool uevents:1;
> > + bool autoeject:1;
> > +};
> > +
> > struct acpi_scan_handler {
> > const struct acpi_device_id *ids;
> > struct list_head list_node;
> > int (*attach)(struct acpi_device *dev, const struct acpi_device_id *id);
> > void (*detach)(struct acpi_device *dev);
> > + struct acpi_hotplug_profile hotplug;
> > };
> >
> > /*
> > Index: test/drivers/acpi/scan.c
> > ===================================================================
> > --- test.orig/drivers/acpi/scan.c
> > +++ test/drivers/acpi/scan.c
> > @@ -107,32 +107,19 @@ acpi_device_modalias_show(struct device
> > }
> > static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, 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)
> > +static int acpi_scan_hot_remove(struct acpi_device *device)
> > {
> > - struct acpi_eject_event *ej_event = context;
> > - struct acpi_device *device = ej_event->device;
> > acpi_handle handle = device->handle;
> > - acpi_handle temp;
> > + acpi_handle not_used;
> > struct acpi_object_list arg_list;
> > union acpi_object arg;
> > - acpi_status status = AE_OK;
> > - u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
> > -
> > - mutex_lock(&acpi_scan_lock);
> > + acpi_status status;
> >
> > /* If there is no handle, the device node has been unregistered. */
> > - if (!device->handle) {
> > + if (!handle) {
> > dev_dbg(&device->dev, "ACPI handle missing\n");
> > put_device(&device->dev);
> > - goto out;
> > + return -EINVAL;
> > }
> >
> > ACPI_DEBUG_PRINT((ACPI_DB_INFO,
> > @@ -143,7 +130,7 @@ void acpi_bus_hot_remove_device(void *co
> > put_device(&device->dev);
> > device = NULL;
> >
> > - if (ACPI_SUCCESS(acpi_get_handle(handle, "_LCK", &temp))) {
> > + if (ACPI_SUCCESS(acpi_get_handle(handle, "_LCK", ¬_used))) {
> > arg_list.count = 1;
> > arg_list.pointer = &arg;
> > arg.type = ACPI_TYPE_INTEGER;
> > @@ -161,18 +148,162 @@ void acpi_bus_hot_remove_device(void *co
> > */
> > status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
> > if (ACPI_FAILURE(status)) {
> > - if (status != AE_NOT_FOUND)
> > + if (status == AE_NOT_FOUND) {
> > + return -ENODEV;
> > + } else {
> > acpi_handle_warn(handle, "Eject failed\n");
> > + return -EIO;
> > + }
> > + }
> > + return 0;
> > +}
> > +
> > +static void acpi_bus_device_eject(void *context)
> > +{
> > + acpi_handle handle = context;
> > + struct acpi_device *device = NULL;
> > + struct acpi_scan_handler *handler;
> > + u32 ost_source = ACPI_NOTIFY_EJECT_REQUEST;
> > + u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
> > +
> > + mutex_lock(&acpi_scan_lock);
> >
> > - /* Tell the firmware the hot-remove operation has failed. */
> > - acpi_evaluate_hotplug_ost(handle, ej_event->event,
> > - ost_code, NULL);
> > + acpi_bus_get_device(handle, &device);
> > + if (!device)
> > + goto out;
> > +
> > + handler = device->handler;
> > + if (!handler || !handler->hotplug.enabled) {
> > + ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
> > + goto out;
> > }
> > + acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
> > + ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
>
> > + if (handler->hotplug.uevents)
> > + kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
> > +
> > + if (handler->hotplug.autoeject) {
> > + int error;
> > +
> > + ost_source = ACPI_OST_EC_OSPM_EJECT;
> > + get_device(&device->dev);
> > + error = acpi_scan_hot_remove(device);
> > + if (!error)
> > + ost_code = ACPI_OST_SC_SUCCESS;
> > + } else {
> > + device->flags.eject_pending = true;
> > + goto out_unlock;
> > + }
>
> I want you to change the order of uevents and autoeject.
> When user caught OFFLINE event, user thinks devices were removed.
> But it is not guaranteed in this code since acpi_scan_hot_remove() may
> be running.
Sure, I can do that.
> > +
> > + out:
> > + acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL);
> > +
> > + out_unlock:
> > + mutex_unlock(&acpi_scan_lock);
> > +}
> > +
> > +static void acpi_scan_bus_device_check(acpi_handle handle, u32 ost_source)
> > +{
> > + struct acpi_device *device = NULL;
> > + u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
> > + int error;
> > +
> > + mutex_lock(&acpi_scan_lock);
> > +
> > + acpi_bus_get_device(handle, &device);
> > + if (device) {
> > + dev_warn(&device->dev, "Attempt to re-insert\n");
> > + goto out;
> > + }
> > + acpi_evaluate_hotplug_ost(handle, ost_source,
> > + ACPI_OST_SC_INSERT_IN_PROGRESS, NULL);
> > + ost_source = ACPI_OST_EC_OSPM_INSERTION;
> > + error = acpi_bus_scan(handle);
> > + if (error) {
> > + acpi_handle_warn(handle, "Namespace scan failure\n");
> > + goto out;
> > + }
> > + error = acpi_bus_get_device(handle, &device);
> > + if (error) {
> > + acpi_handle_warn(handle, "Missing device node object\n");
> > + goto out;
> > + }
> > + ost_code = ACPI_OST_SC_SUCCESS;
> > + if (device->handler && device->handler->hotplug.uevents)
> > + kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
> >
> > out:
> > + acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL);
> > + mutex_unlock(&acpi_scan_lock);
> > +}
> > +
> > +static void acpi_scan_bus_check(void *context)
> > +{
> > + acpi_scan_bus_device_check((acpi_handle)context,
> > + ACPI_NOTIFY_BUS_CHECK);
> > +}
> > +
> > +static void acpi_scan_device_check(void *context)
> > +{
> > + acpi_scan_bus_device_check((acpi_handle)context,
> > + ACPI_NOTIFY_DEVICE_CHECK);
> > +}
> > +
> > +static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *not_used)
> > +{
> > + acpi_osd_exec_callback callback;
> > + acpi_status status;
> > +
> > + switch (type) {
> > + case ACPI_NOTIFY_BUS_CHECK:
> > + acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
> > + callback = acpi_scan_bus_check;
> > + break;
> > + case ACPI_NOTIFY_DEVICE_CHECK:
> > + acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
> > + callback = acpi_scan_device_check;
> > + break;
> > + case ACPI_NOTIFY_EJECT_REQUEST:
> > + acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
> > + callback = acpi_bus_device_eject;
> > + break;
> > + default:
> > + /* non-hotplug event; possibly handled by other handler */
> > + return;
> > + }
> > + status = acpi_os_hotplug_execute(callback, handle);
> > + if (ACPI_FAILURE(status))
> > + acpi_evaluate_hotplug_ost(handle, type,
> > + ACPI_OST_SC_NON_SPECIFIC_FAILURE,
> > + 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)
> > +{
> > + struct acpi_eject_event *ej_event = context;
> > + struct acpi_device *device = ej_event->device;
> > + acpi_handle handle = device->handle;
> > + u32 ost_code = ACPI_OST_SC_SUCCESS;
> > + int error;
> > +
> > + mutex_lock(&acpi_scan_lock);
> > +
> > + error = acpi_scan_hot_remove(device);
> > + if (error)
> > + ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
> > +
> > + acpi_evaluate_hotplug_ost(handle, ej_event->event, ost_code, NULL);
> > +
> > mutex_unlock(&acpi_scan_lock);
> > kfree(context);
> > - return;
> > }
> > EXPORT_SYMBOL(acpi_bus_hot_remove_device);
> >
> > @@ -206,50 +337,48 @@ static ssize_t
> > acpi_eject_store(struct device *d, struct device_attribute *attr,
> > const char *buf, size_t count)
> > {
> > - int ret = count;
> > - acpi_status status;
> > - acpi_object_type type = 0;
> > struct acpi_device *acpi_device = to_acpi_device(d);
> > - struct acpi_eject_event *ej_event;
> > + acpi_object_type not_used;
> > + acpi_status status;
> > + u32 ost_source;
> > + u32 ost_code;
> > + int ret;
> >
> > - if ((!count) || (buf[0] != '1')) {
> > + if (!count || buf[0] != '1')
> > return -EINVAL;
> > - }
> > - if (!acpi_device->driver && !acpi_device->handler) {
> > - ret = -ENODEV;
> > - goto err;
> > - }
> > - status = acpi_get_type(acpi_device->handle, &type);
> > - if (ACPI_FAILURE(status) || (!acpi_device->flags.ejectable)) {
> > - ret = -ENODEV;
> > - goto err;
> > - }
> >
> > - ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
> > - if (!ej_event) {
> > - ret = -ENOMEM;
> > - goto err;
> > - }
> > + if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
> > + && !acpi_device->driver)
> > + return -ENODEV;
> > +
> > + status = acpi_get_type(acpi_device->handle, ¬_used);
> > + if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
> > + return -ENODEV;
> > +
> > + mutex_lock(&acpi_scan_lock);
> >
> > - get_device(&acpi_device->dev);
> > - ej_event->device = acpi_device;
> > if (acpi_device->flags.eject_pending) {
> > - /* event originated from ACPI eject notification */
> > - ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
> > + /* ACPI eject notification event. */
> > + ost_source = ACPI_NOTIFY_EJECT_REQUEST;
> > acpi_device->flags.eject_pending = 0;
> > } else {
> > - /* event originated from user */
> > - ej_event->event = ACPI_OST_EC_OSPM_EJECT;
> > - (void) acpi_evaluate_hotplug_ost(acpi_device->handle,
> > - ej_event->event, ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
> > + /* Eject initiated by user space. */
> > + ost_source = ACPI_OST_EC_OSPM_EJECT;
> > }
> > -
>
> > - status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
> > - if (ACPI_FAILURE(status)) {
> > - put_device(&acpi_device->dev);
> > - kfree(ej_event);
> > + acpi_evaluate_hotplug_ost(acpi_device->handle, ost_source,
> > + ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
> > + get_device(&acpi_device->dev);
> > + ret = acpi_scan_hot_remove(acpi_device);
>
> Why don't you use acpi_os_hotplug_execute()? Do you have some reason?
Yes, I do. acpi_eject_store() is run in a separate thread anyway (started by
user space), so there's no need to use the workqueue for delayed execution here
and we are under acpi_scan_lock anyway, so there shouldn't be any concurrency
issues.
Thanks,
Rafael
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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