lkml.org 
[lkml]   [2012]   [Jul]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [RFC PATCH 10/13] driver core: devres: introduce devres_for_each_res
On Wed, Jul 25, 2012 at 01:00:10AM +0800, Ming Lei wrote:
> This patch introduces one devres API of devres_for_each_res
> so that the device's driver can iterate each resource it has
> interest in.
>
> The firmware loader will use the API to get each firmware name
> from the device instance.
>
> Signed-off-by: Ming Lei <ming.lei@canonical.com>
> ---
> drivers/base/devres.c | 42 ++++++++++++++++++++++++++++++++++++++++++
> include/linux/device.h | 3 +++
> 2 files changed, 45 insertions(+)
>
> diff --git a/drivers/base/devres.c b/drivers/base/devres.c
> index 2360adb..8273ba5 100644
> --- a/drivers/base/devres.c
> +++ b/drivers/base/devres.c
> @@ -144,6 +144,48 @@ EXPORT_SYMBOL_GPL(devres_alloc);
> #endif
>
> /**
> + * devres_for_each_res - Resource iterator
> + * @dev: Device to iterate resource from
> + * @release: Look for resources associated with this release function
> + * @match: Match function (optional)
> + * @match_data: Data for the match function
> + * @fn: function to be called for each matched resource.
> + *
> + * Call @fn for each devres of @dev which is associated with @release
> + * and for which @match returns 1.
> + *
> + * RETURNS:
> + * void
> + */
> +void devres_for_each_res(struct device *dev, dr_release_t release,
> + dr_match_t match, void *match_data,
> + void (*fn)(struct device *, void *))
> +{
> + struct devres_node *node;
> + struct devres_node *tmp;
> + unsigned long flags;
> +
> + if (!fn)
> + return;
> +
> + spin_lock_irqsave(&dev->devres_lock, flags);
> + list_for_each_entry_safe_reverse(node, tmp,
> + &dev->devres_head, entry) {

Why break this line?

list_for_each_entry_safe_reverse(node, tmp, &dev->devres_head, entry) {

is perfectly fine.

> + struct devres *dr = container_of(node, struct devres, node);
> +
> + if (node->release != release)
> + continue;
> + if (match && !match(dev, dr->data, match_data))
> + continue;
> + spin_unlock_irqrestore(&dev->devres_lock, flags);
> + fn(dev, dr->data);
> + spin_lock_irqsave(&dev->devres_lock, flags);
> + }
> + spin_unlock_irqrestore(&dev->devres_lock, flags);

This looks strange. For the last node on the list, we're grabbing the
lock and releasing it right after.

Probably check whether node is the last element and only re-grab the
lock if it isn't?

And btw, don't we need to hold the ->devres_lock during the whole search
like callers of find_dr do, for example?

> +}
> +EXPORT_SYMBOL_GPL(devres_for_each_res);
> +
> +/**
> * devres_free - Free device resource data
> * @res: Pointer to devres data to free
> *
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 52a5f15..34dc1f8 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -536,6 +536,9 @@ extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
> #else
> extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
> #endif
> +extern void devres_for_each_res(struct device *dev, dr_release_t release,
> + dr_match_t match, void *match_data,
> + void (*fn)(struct device *, void *));

Args alignment.

> extern void devres_free(void *res);
> extern void devres_add(struct device *dev, void *res);
> extern void *devres_find(struct device *dev, dr_release_t release,
> --
> 1.7.9.5
>
>

--
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551

\
 
 \ /
  Last update: 2012-07-25 19:01    [W:0.150 / U:5.948 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site