Re: [PATCH 6/8] drm/{i915,xe}/panic: move framebuffer allocation where it belongs

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Oct 01, 2025 at 06:04:58PM +0300, Jani Nikula wrote:
> On Tue, 02 Sep 2025, Jani Nikula <jani.nikula@intel.com> wrote:
> > The struct intel_framebuffer allocation naturally belongs in intel_fb.c,
> > not hidden inside panic implementation. Separate the panic
> > allocation. Drop the unnecessary struct i915_framebuffer and struct
> > xe_framebuffer types.
> >
> > Cc: Jocelyn Falempe <jfalempe@redhat.com>
> > Cc: Maarten Lankhorst <dev@lankhorst.se>
> > Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_fb.c    | 17 ++++++++++++++++-
> >  drivers/gpu/drm/i915/display/intel_panic.c |  4 ++--
> >  drivers/gpu/drm/i915/display/intel_panic.h |  3 ++-
> >  drivers/gpu/drm/i915/gem/i915_gem_object.h |  5 +++--
> >  drivers/gpu/drm/i915/gem/i915_gem_pages.c  | 17 ++++-------------
> >  drivers/gpu/drm/xe/display/xe_panic.c      | 17 ++++-------------
> >  6 files changed, 31 insertions(+), 32 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_fb.c b/drivers/gpu/drm/i915/display/intel_fb.c
> > index 2a2ed0f0461f..22a4a1575d22 100644
> > --- a/drivers/gpu/drm/i915/display/intel_fb.c
> > +++ b/drivers/gpu/drm/i915/display/intel_fb.c
> > @@ -2346,7 +2346,22 @@ intel_user_framebuffer_create(struct drm_device *dev,
> >  
> >  struct intel_framebuffer *intel_framebuffer_alloc(void)
> >  {
> > -	return intel_bo_alloc_framebuffer();
> > +	struct intel_framebuffer *intel_fb;
> > +	struct intel_panic *panic;
> > +
> > +	intel_fb = kzalloc(sizeof(*intel_fb), GFP_KERNEL);
> > +	if (!intel_fb)
> > +		return NULL;
> > +
> > +	panic = intel_panic_alloc();
> > +	if (!panic) {
> > +		kfree(intel_fb);
> > +		return NULL;
> > +	}
> > +
> > +	intel_fb->panic = panic;
> 
> So I screwed up here. There's no deallocation of fb->panic, and this
> leaks. I don't know what I was thinking.
> 
> To make matters worse, struct intel_framebuffer is deallocated via
> drm_framebuffer_put() i.e. there's no obvious place to plug the free in.

intel_user_framebuffer_destroy()

And someone should probably s/_user// on all those fb func to
make things less confusing.

> 
> Any ideas before I start looking at reverting the changes, and get back
> to the drawing board with abstracting the code between i915 and xe?
> 
> BR,
> Jani.
> 
> > +
> > +	return intel_fb;
> >  }
> >  
> >  struct drm_framebuffer *
> > diff --git a/drivers/gpu/drm/i915/display/intel_panic.c b/drivers/gpu/drm/i915/display/intel_panic.c
> > index 20eecb0f168f..5431bd4d3a7d 100644
> > --- a/drivers/gpu/drm/i915/display/intel_panic.c
> > +++ b/drivers/gpu/drm/i915/display/intel_panic.c
> > @@ -4,9 +4,9 @@
> >  #include "gem/i915_gem_object.h"
> >  #include "intel_panic.h"
> >  
> > -struct intel_framebuffer *intel_bo_alloc_framebuffer(void)
> > +struct intel_panic *intel_panic_alloc(void)
> >  {
> > -	return i915_gem_object_alloc_framebuffer();
> > +	return i915_gem_object_alloc_panic();
> >  }
> >  
> >  int intel_panic_setup(struct drm_scanout_buffer *sb)
> > diff --git a/drivers/gpu/drm/i915/display/intel_panic.h b/drivers/gpu/drm/i915/display/intel_panic.h
> > index 67ce253fcdf5..45ce6104e6fb 100644
> > --- a/drivers/gpu/drm/i915/display/intel_panic.h
> > +++ b/drivers/gpu/drm/i915/display/intel_panic.h
> > @@ -6,8 +6,9 @@
> >  
> >  struct drm_scanout_buffer;
> >  struct intel_framebuffer;
> > +struct intel_panic;
> >  
> > -struct intel_framebuffer *intel_bo_alloc_framebuffer(void);
> > +struct intel_panic *intel_panic_alloc(void);
> >  int intel_panic_setup(struct drm_scanout_buffer *sb);
> >  void intel_panic_finish(struct intel_framebuffer *fb);
> >  
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
> > index 565f8fa330db..9b3f25cb48db 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
> > @@ -16,9 +16,10 @@
> >  #include "i915_gem_ww.h"
> >  #include "i915_vma_types.h"
> >  
> > -struct drm_scanout_buffer;
> >  enum intel_region_id;
> > +struct drm_scanout_buffer;
> >  struct intel_framebuffer;
> > +struct intel_panic;
> >  
> >  #define obj_to_i915(obj__) to_i915((obj__)->base.dev)
> >  
> > @@ -693,7 +694,7 @@ i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj)
> >  int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj);
> >  int i915_gem_object_truncate(struct drm_i915_gem_object *obj);
> >  
> > -struct intel_framebuffer *i915_gem_object_alloc_framebuffer(void);
> > +struct intel_panic *i915_gem_object_alloc_panic(void);
> >  int i915_gem_object_panic_setup(struct drm_scanout_buffer *sb);
> >  void i915_gem_object_panic_finish(struct intel_framebuffer *fb);
> >  
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> > index e36d60b785b1..b219474aecc7 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> > @@ -363,11 +363,6 @@ struct intel_panic {
> >  	void *vaddr;
> >  };
> >  
> > -struct i915_framebuffer {
> > -	struct intel_framebuffer base;
> > -	struct intel_panic panic;
> > -};
> > -
> >  static void i915_panic_kunmap(struct intel_panic *panic)
> >  {
> >  	if (panic->vaddr) {
> > @@ -436,17 +431,13 @@ static void i915_gem_object_panic_page_set_pixel(struct drm_scanout_buffer *sb,
> >  	}
> >  }
> >  
> > -struct intel_framebuffer *i915_gem_object_alloc_framebuffer(void)
> > +struct intel_panic *i915_gem_object_alloc_panic(void)
> >  {
> > -	struct i915_framebuffer *i915_fb;
> > -
> > -	i915_fb = kzalloc(sizeof(*i915_fb), GFP_KERNEL);
> > -	if (!i915_fb)
> > -		return NULL;
> > +	struct intel_panic *panic;
> >  
> > -	i915_fb->base.panic = &i915_fb->panic;
> > +	panic = kzalloc(sizeof(*panic), GFP_KERNEL);
> >  
> > -	return &i915_fb->base;
> > +	return panic;
> >  }
> >  
> >  /*
> > diff --git a/drivers/gpu/drm/xe/display/xe_panic.c b/drivers/gpu/drm/xe/display/xe_panic.c
> > index 3ef23a6795b3..b5a7615708a1 100644
> > --- a/drivers/gpu/drm/xe/display/xe_panic.c
> > +++ b/drivers/gpu/drm/xe/display/xe_panic.c
> > @@ -15,11 +15,6 @@ struct intel_panic {
> >  	void *vaddr;
> >  };
> >  
> > -struct xe_framebuffer {
> > -	struct intel_framebuffer base;
> > -	struct intel_panic panic;
> > -};
> > -
> >  static void xe_panic_kunmap(struct intel_panic *panic)
> >  {
> >  	if (panic->vaddr) {
> > @@ -62,17 +57,13 @@ static void xe_panic_page_set_pixel(struct drm_scanout_buffer *sb, unsigned int
> >  	}
> >  }
> >  
> > -struct intel_framebuffer *intel_bo_alloc_framebuffer(void)
> > +struct intel_panic *intel_panic_alloc(void)
> >  {
> > -	struct xe_framebuffer *xe_fb;
> > -
> > -	xe_fb = kzalloc(sizeof(*xe_fb), GFP_KERNEL);
> > -	if (!xe_fb)
> > -		return NULL;
> > +	struct intel_panic *panic;
> >  
> > -	xe_fb->base.panic = &xe_fb->panic;
> > +	panic = kzalloc(sizeof(*panic), GFP_KERNEL);
> >  
> > -	return &xe_fb->base;
> > +	return panic;
> >  }
> >  
> >  int intel_panic_setup(struct drm_scanout_buffer *sb)
> 
> -- 
> Jani Nikula, Intel

-- 
Ville Syrjälä
Intel