Re: [PATCH v3 1/3] Use acpi_os_hotplug_execute() instead of alloc_acpi_hp_work().

From: Yinghai Lu
Date: Wed Oct 31 2012 - 23:52:21 EST


On Wed, Oct 31, 2012 at 12:27 AM, Tang Chen <tangchen@xxxxxxxxxxxxxx> wrote:
> Hi Yinghai,
>
> alloc_acpi_hp_work() just puts the hutplug work onto kacpi_hotplug_wq.
> As mentioned by Toshi Kani, this job has been done in acpi_os_hotplug_execute().
> So we should use it instead of alloc_acpi_hp_work().
>
> This patch adds a acpi_hp_cb_data struct, which encapsulates the hotplug
> event notifier's parameters:
> struct acpi_hp_cb_data {
> acpi_handle handle;
> u32 type;
> void *context;
> };
>
> And also a function alloc_acpi_hp_work(), which calls acpi_os_hotplug_execute()
> to put the hotplug job onto kacpi_hotplug_wq.
>
> This patch is based on Lu Yinghai's tree:
> git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git for-pci-split-pci-root-hp-2
>
> Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
> ---
> drivers/acpi/osl.c | 28 ++++++++++++------------
> drivers/acpi/pci_root_hp.c | 25 +++++++++++++++-------
> drivers/pci/hotplug/acpiphp_glue.c | 39 +++++++++++++++++++----------------
> include/acpi/acpiosxf.h | 7 ++---
> 4 files changed, 55 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
> index 311a921..d441b16 100644
> --- a/drivers/acpi/osl.c
> +++ b/drivers/acpi/osl.c
> @@ -52,6 +52,7 @@
> #include <acpi/acpi.h>
> #include <acpi/acpi_bus.h>
> #include <acpi/processor.h>
> +#include <acpi/acpiosxf.h>

not needed.

>
> #define _COMPONENT ACPI_OS_SERVICES
> ACPI_MODULE_NAME("osl");
> @@ -1592,23 +1593,22 @@ void acpi_os_set_prepare_sleep(int (*func)(u8 sleep_state,
> __acpi_os_prepare_sleep = func;
> }
>
> -void alloc_acpi_hp_work(acpi_handle handle, u32 type, void *context,
> - void (*func)(struct work_struct *work))
> +void acpi_hp_cb_execute(acpi_handle handle, u32 type, void *context,
> + acpi_osd_exec_callback function)
> {
> - struct acpi_hp_work *hp_work;
> - int ret;
> + acpi_status status;
> + struct acpi_hp_cb_data *cb_data;
>
> - hp_work = kmalloc(sizeof(*hp_work), GFP_KERNEL);
> - if (!hp_work)
> + cb_data = kmalloc(sizeof(struct acpi_hp_cb_data), GFP_KERNEL);
> + if (!cb_data)
> return;
>
> - hp_work->handle = handle;
> - hp_work->type = type;
> - hp_work->context = context;
> + cb_data->handle = handle;
> + cb_data->type = type;
> + cb_data->context = context;
>
> - INIT_WORK(&hp_work->work, func);
> - ret = queue_work(kacpi_hotplug_wq, &hp_work->work);
> - if (!ret)
> - kfree(hp_work);
> + status = acpi_os_hotplug_execute(function, cb_data);
> + if (ACPI_FAILURE(status))
> + kfree(cb_data);
> }
> -EXPORT_SYMBOL(alloc_acpi_hp_work);
> +EXPORT_SYMBOL(acpi_hp_cb_execute);
> diff --git a/drivers/acpi/pci_root_hp.c b/drivers/acpi/pci_root_hp.c
> index 7d427e6..2ff83f4 100644
> --- a/drivers/acpi/pci_root_hp.c
> +++ b/drivers/acpi/pci_root_hp.c
> @@ -75,19 +75,20 @@ static void handle_root_bridge_removal(struct acpi_device *device)
> acpi_bus_hot_remove_device(ej_event);
> }
>
> -static void _handle_hotplug_event_root(struct work_struct *work)
> +/* This function is of type acpi_osd_exec_callback */
> +static void _handle_hotplug_event_root(void *context)
> {
> struct acpi_pci_root *root;
> char objname[64];
> struct acpi_buffer buffer = { .length = sizeof(objname),
> .pointer = objname };
> - struct acpi_hp_work *hp_work;
> + struct acpi_hp_cb_data *cb_data;
> acpi_handle handle;
> u32 type;
>
> - hp_work = container_of(work, struct acpi_hp_work, work);
> - handle = hp_work->handle;
> - type = hp_work->type;
> + cb_data = (struct acpi_hp_cb_data *)context;
> + handle = cb_data->handle;
> + type = cb_data->type;
>
> root = acpi_pci_find_root(handle);
>
> @@ -124,14 +125,22 @@ static void _handle_hotplug_event_root(struct work_struct *work)
> break;
> }
>
> - kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
> + kfree(context); /* allocated in handle_hotplug_event_bridge */
> }
>
> static void handle_hotplug_event_root(acpi_handle handle, u32 type,
> void *context)
> {
> - alloc_acpi_hp_work(handle, type, context,
> - _handle_hotplug_event_root);
> + /*
> + * Currently the code adds all hotplug events to the kacpid_wq
> + * queue when it should add hotplug events to the kacpi_hotplug_wq.
> + * The proper way to fix this is to reorganize the code so that
> + * drivers (dock, etc.) do not call acpi_os_execute(), etc.
> + * For now just re-add this work to the kacpi_hotplug_wq so we
> + * don't deadlock on hotplug actions.
> + */
> + acpi_hp_cb_execute(handle, type, context,
> + _handle_hotplug_event_root);
> }
>
> static bool acpi_is_root_bridge_object(acpi_handle handle)
> diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
> index 0833d2e..b30fc37 100644
> --- a/drivers/pci/hotplug/acpiphp_glue.c
> +++ b/drivers/pci/hotplug/acpiphp_glue.c
> @@ -50,6 +50,8 @@
> #include <linux/slab.h>
> #include <linux/acpi.h>
>
> +#include <acpi/acpiosxf.h>
> +

not needed.

> #include "../pci.h"
> #include "acpiphp.h"
>
> @@ -1209,7 +1211,8 @@ check_sub_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
> return AE_OK ;
> }
>
> -static void _handle_hotplug_event_bridge(struct work_struct *work)
> +/* This function is of type acpi_osd_exec_callback */
> +static void _handle_hotplug_event_bridge(void *context)
> {
> struct acpiphp_bridge *bridge;
> char objname[64];
> @@ -1217,13 +1220,13 @@ static void _handle_hotplug_event_bridge(struct work_struct *work)
> .pointer = objname };
> struct acpi_device *device;
> int num_sub_bridges = 0;
> - struct acpi_hp_work *hp_work;
> + struct acpi_hp_cb_data *cb_data;
> acpi_handle handle;
> u32 type;
>
> - hp_work = container_of(work, struct acpi_hp_work, work);
> - handle = hp_work->handle;
> - type = hp_work->type;
> + cb_data = (struct acpi_hp_cb_data *)context;
> + handle = cb_data->handle;
> + type = cb_data->type;
>
> if (acpi_bus_get_device(handle, &device)) {
> /* This bridge must have just been physically inserted */
> @@ -1302,7 +1305,7 @@ static void _handle_hotplug_event_bridge(struct work_struct *work)
> }
>
> out:
> - kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
> + kfree(context); /* allocated in handle_hotplug_event_bridge */
> }
>
> /**
> @@ -1324,29 +1327,28 @@ static void handle_hotplug_event_bridge(acpi_handle handle, u32 type,
> * For now just re-add this work to the kacpi_hotplug_wq so we
> * don't deadlock on hotplug actions.
> */
> - alloc_acpi_hp_work(handle, type, context, _handle_hotplug_event_bridge);
> + acpi_hp_cb_execute(handle, type, context,
> + _handle_hotplug_event_bridge);
> }
>
> -static void _handle_hotplug_event_func(struct work_struct *work)
> +/* This function is of type acpi_osd_exec_callback */
> +static void _handle_hotplug_event_func(void *context)
> {
> struct acpiphp_func *func;
> char objname[64];
> struct acpi_buffer buffer = { .length = sizeof(objname),
> .pointer = objname };
> - struct acpi_hp_work *hp_work;
> + struct acpi_hp_cb_data *cb_data;
> acpi_handle handle;
> u32 type;
> - void *context;
>
> - hp_work = container_of(work, struct acpi_hp_work, work);
> - handle = hp_work->handle;
> - type = hp_work->type;
> - context = hp_work->context;
> + cb_data = (struct acpi_hp_cb_data *)context;
> + handle = cb_data->handle;
> + type = cb_data->type;
> + func = (struct acpiphp_func *)cb_data->context;

too many context looks confusing.

>
> acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
>
> - func = (struct acpiphp_func *)context;
> -
> switch (type) {
> case ACPI_NOTIFY_BUS_CHECK:
> /* bus re-enumerate */
> @@ -1377,7 +1379,7 @@ static void _handle_hotplug_event_func(struct work_struct *work)
> break;
> }
>
> - kfree(hp_work); /* allocated in handle_hotplug_event_func */
> + kfree(context); /* allocated in handle_hotplug_event_func */
> }
>
> /**
> @@ -1399,7 +1401,8 @@ static void handle_hotplug_event_func(acpi_handle handle, u32 type,
> * For now just re-add this work to the kacpi_hotplug_wq so we
> * don't deadlock on hotplug actions.
> */
> - alloc_acpi_hp_work(handle, type, context, _handle_hotplug_event_func);
> + acpi_hp_cb_execute(handle, type, context,
> + _handle_hotplug_event_func);
> }
>
> static struct acpi_pci_driver acpi_pci_hp_driver = {
> diff --git a/include/acpi/acpiosxf.h b/include/acpi/acpiosxf.h
> index 9f68f69..8825891 100644
> --- a/include/acpi/acpiosxf.h
> +++ b/include/acpi/acpiosxf.h
> @@ -194,14 +194,13 @@ void acpi_os_fixed_event_count(u32 fixed_event_number);
> /*
> * Threads and Scheduling
> */
> -struct acpi_hp_work {
> - struct work_struct work;
> +struct acpi_hp_cb_data {
> acpi_handle handle;
> u32 type;
> void *context;
> };
> -void alloc_acpi_hp_work(acpi_handle handle, u32 type, void *context,
> - void (*func)(struct work_struct *work));
> +void acpi_hp_cb_execute(acpi_handle handle, u32 type, void *context,
> + acpi_osd_exec_callback function);
>
> acpi_thread_id acpi_os_get_thread_id(void);

Please check if you can just fold
acpi_hp_cb_execute
callers, and use acpi_os_hotplug_execute directly.

and have two local conext struct too.

>
> --
> 1.7.1
>
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