[PATCH v2 1/2] drm: add drmm_encoder_init()

Daniel Vetter daniel at ffwll.ch
Fri Jul 24 09:37:56 UTC 2020


On Fri, Jul 24, 2020 at 11:33 AM Thomas Zimmermann <tzimmermann at suse.de> wrote:
>
> Hi
>
> Am 24.07.20 um 11:07 schrieb Daniel Vetter:
> > On Fri, Jul 24, 2020 at 10:49 AM Philipp Zabel <p.zabel at pengutronix.de> wrote:
> >>
> >> On Thu, 2020-07-23 at 16:56 +0200, Philipp Zabel wrote:
> >>> Add a drm_encoder_init() variant that allocates an encoder with
> >>> drmm_kzalloc() and registers drm_encoder_cleanup() with
> >>> drmm_add_action_or_reset().
> >>>
> >>> Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
> >
> > Thanks for doing this!
> >
> >>> ---
> >>> New in v2
> >>> ---
> >>>  drivers/gpu/drm/drm_encoder.c | 101 ++++++++++++++++++++++++++--------
> >>>  include/drm/drm_encoder.h     |  30 ++++++++++
> >>>  2 files changed, 108 insertions(+), 23 deletions(-)
> >>>
> >>> diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c
> >>> index e555281f43d4..91184f67333c 100644
> >>> --- a/drivers/gpu/drm/drm_encoder.c
> >>> +++ b/drivers/gpu/drm/drm_encoder.c
> >>> @@ -26,6 +26,7 @@
> >>>  #include <drm/drm_device.h>
> >>>  #include <drm/drm_drv.h>
> >>>  #include <drm/drm_encoder.h>
> >>> +#include <drm/drm_managed.h>
> >>>
> >>>  #include "drm_crtc_internal.h"
> >>>
> >>> @@ -91,25 +92,10 @@ void drm_encoder_unregister_all(struct drm_device *dev)
> >>>       }
> >>>  }
> >>>
> >>> -/**
> >>> - * drm_encoder_init - Init a preallocated encoder
> >>> - * @dev: drm device
> >>> - * @encoder: the encoder to init
> >>> - * @funcs: callbacks for this encoder
> >>> - * @encoder_type: user visible type of the encoder
> >>> - * @name: printf style format string for the encoder name, or NULL for default name
> >>> - *
> >>> - * Initialises a preallocated encoder. Encoder should be subclassed as part of
> >>> - * driver encoder objects. At driver unload time drm_encoder_cleanup() should be
> >>> - * called from the driver's &drm_encoder_funcs.destroy hook.
> >>> - *
> >>> - * Returns:
> >>> - * Zero on success, error code on failure.
> >>> - */
> >>> -int drm_encoder_init(struct drm_device *dev,
> >>> -                  struct drm_encoder *encoder,
> >>> -                  const struct drm_encoder_funcs *funcs,
> >>> -                  int encoder_type, const char *name, ...)
> >>> +static int __drm_encoder_init(struct drm_device *dev,
> >>> +                           struct drm_encoder *encoder,
> >>> +                           const struct drm_encoder_funcs *funcs,
> >>> +                           int encoder_type, const char *name, va_list ap)
> >>>  {
> >>>       int ret;
> >>>
> >>> @@ -125,11 +111,7 @@ int drm_encoder_init(struct drm_device *dev,
> >>>       encoder->encoder_type = encoder_type;
> >>>       encoder->funcs = funcs;
> >>>       if (name) {
> >>> -             va_list ap;
> >>> -
> >>> -             va_start(ap, name);
> >>>               encoder->name = kvasprintf(GFP_KERNEL, name, ap);
> >>> -             va_end(ap);
> >>>       } else {
> >>>               encoder->name = kasprintf(GFP_KERNEL, "%s-%d",
> >>>                                         drm_encoder_enum_list[encoder_type].name,
> >>> @@ -150,6 +132,38 @@ int drm_encoder_init(struct drm_device *dev,
> >>>
> >>>       return ret;
> >>>  }
> >>> +
> >>> +/**
> >>> + * drm_encoder_init - Init a preallocated encoder
> >>> + * @dev: drm device
> >>> + * @encoder: the encoder to init
> >>> + * @funcs: callbacks for this encoder
> >>> + * @encoder_type: user visible type of the encoder
> >>> + * @name: printf style format string for the encoder name, or NULL for default name
> >>> + *
> >>> + * Initialises a preallocated encoder. Encoder should be subclassed as part of
> >>> + * driver encoder objects. At driver unload time drm_encoder_cleanup() should be
> >>> + * called from the driver's &drm_encoder_funcs.destroy hook.
> >>> + *
> >>> + * Returns:
> >>> + * Zero on success, error code on failure.
> >>> + */
> >>> +int drm_encoder_init(struct drm_device *dev,
> >>> +                  struct drm_encoder *encoder,
> >>> +                  const struct drm_encoder_funcs *funcs,
> >>> +                  int encoder_type, const char *name, ...)
> >>> +{
> >>> +     va_list ap;
> >>> +     int ret;
> >>> +
> >>> +     if (name)
> >>> +             va_start(ap, name);
> >>> +     ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
> >>> +     if (name)
> >>> +             va_end(ap);
> >>> +
> >>> +     return ret;
> >>> +}
> >>>  EXPORT_SYMBOL(drm_encoder_init);
> >>>
> >>>  /**
> >>> @@ -181,6 +195,47 @@ void drm_encoder_cleanup(struct drm_encoder *encoder)
> >>>  }
> >>>  EXPORT_SYMBOL(drm_encoder_cleanup);
> >>>
> >>> +void drmm_encoder_init_release(struct drm_device *dev, void *ptr)
> >>> +{
> >>> +     struct drm_encoder *encoder = ptr;
> >>
> >> I'll add
> >>
> >>         if (WARN_ON(!encoder->dev))
> >>                 return;
> >>
> >> here.
> >>
> >>> +     drm_encoder_cleanup(encoder);
> >>> +}
> >>> +
> >>> +void *__drmm_encoder_init(struct drm_device *dev, size_t size, size_t offset,
> >>> +                       const struct drm_encoder_funcs *funcs,
> >>> +                       int encoder_type, const char *name, ...)
> >>> +{
> >>> +     void *container;
> >>> +     struct drm_encoder *encoder;
> >>> +     va_list ap;
> >>> +     int ret;
> >>> +
> >>> +     if (WARN_ON(!funcs || funcs->destroy))
> >>> +             return ERR_PTR(-EINVAL);
> >>> +
> >>> +     container = drmm_kzalloc(dev, size, GFP_KERNEL);
> >>> +     if (!container)
> >>> +             return ERR_PTR(-EINVAL);
> >>> +
> >>> +     encoder = container + offset;
> >>> +
> >>> +     if (name)
> >>> +             va_start(ap, name);
> >>> +     ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
> >>> +     if (name)
> >>> +             va_end(ap);
> >>> +     if (ret)
> >>> +             return ERR_PTR(ret);
> >>> +
> >>> +     ret = drmm_add_action_or_reset(dev, drmm_encoder_init_release, encoder);
> >>> +     if (ret)
> >>> +             return ERR_PTR(ret);
> >>> +
> >>> +     return container;
> >>> +}
> >>> +EXPORT_SYMBOL(__drmm_encoder_init);
> >>> +
> >>>  static struct drm_crtc *drm_encoder_get_crtc(struct drm_encoder *encoder)
> >>>  {
> >>>       struct drm_connector *connector;
> >>> diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h
> >>> index a60f5f1555ac..54b82554ee88 100644
> >>> --- a/include/drm/drm_encoder.h
> >>> +++ b/include/drm/drm_encoder.h
> >>> @@ -195,6 +195,36 @@ int drm_encoder_init(struct drm_device *dev,
> >>>                    const struct drm_encoder_funcs *funcs,
> >>>                    int encoder_type, const char *name, ...);
> >>>
> >>> +__printf(6, 7)
> >>> +void *__drmm_encoder_init(struct drm_device *dev,
> >>> +                       size_t size, size_t offset,
> >>> +                       const struct drm_encoder_funcs *funcs,
> >>> +                       int encoder_type,
> >>> +                       const char *name, ...);
> >>> +
> >>> +/**
> >>> + * drmm_encoder_init - Allocate and initialize an encoder
> >>> + * @dev: drm device
> >>> + * @type: the type of the struct which contains struct &drm_encoder
> >>> + * @member: the name of the &drm_encoder within @type.
> >>> + * @funcs: callbacks for this encoder
> >>> + * @encoder_type: user visible type of the encoder
> >>> + * @name: printf style format string for the encoder name, or NULL for default name
> >>> + *
> >>> + * Allocates and initializes an encoder. Encoder should be subclassed as part of
> >>> + * driver encoder objects. Cleanup is automatically handled through registering
> >>> + * drm_encoder_cleanup() with drmm_add_action().
> >>> + *
> >>> + * The @drm_encoder_funcs.destroy hook must be NULL.
> >>> + *
> >>> + * Returns:
> >>> + * Pointer to new encoder, or ERR_PTR on failure.
> >>> + */
> >>> +#define drmm_encoder_init(dev, type, member, funcs, encoder_type, name, ...) \
> >>> +     ((type *) __drmm_encoder_init(dev, sizeof(type), \
> >>> +                                   offsetof(type, member), funcs, \
> >>> +                                   encoder_type, name, ##__VA_ARGS__))
> >>> +
> >>
> >> Should this be called drmm_encoder_alloc instead?
> >
> > Yes. Same for the internal helper for consistency. Also see my other
>
> I'd suggest calling it drmm_encoder_create() to express that it's _alloc
> + _init. Calling it just _alloc sounds as if it doesn't do the _init.

At least in drm the pattern we've had thus far is alloc = kzalloc +
init. We do use create, but that's for properties and files and stuff,
not allocating/initing driver objects.

So maybe a bit a bikeshed, but imo alloc() is more consistent with
e.g. devm_drm_dev_alloc. Otherwise I think we should rename that one
(and all related ones) for consistency.
-Daniel

>
> Best regards
> Thomas
>
> > reply, if the _alloc() variant is all that's needed that makes me
> > happy, since then we don't need to code up the drmm_assert_managed
> > check for the _init() variants to make sure drivers dont give it
> > something stupid like a devm_kzalloc range :-)
> > -Daniel
> >
>
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 Nürnberg, Germany
> (HRB 36809, AG Nürnberg)
> Geschäftsführer: Felix Imendörffer
>


-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch


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