Re: [RFC v4 02/14] drm/i915/vm_bind: Add __i915_sw_fence_await_reservation()

[Niranjana Vishwanathapura <niranjana.vishwanathapura@xxxxxxxxx>]

On Wed, Sep 21, 2022 at 10:06:48AM +0100, Tvrtko Ursulin wrote:
> On 21/09/2022 08:09, Niranjana Vishwanathapura wrote:
> > Add function __i915_sw_fence_await_reservation() for
> > asynchronous wait on a dma-resv object with specified
> > dma_resv_usage. This is required for async vma unbind
> > with vm_bind.
> >
> > Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@xxxxxxxxx>
> > ---
> >  drivers/gpu/drm/i915/i915_sw_fence.c | 25 ++++++++++++++++++-------
> >  drivers/gpu/drm/i915/i915_sw_fence.h |  7 ++++++-
> >  2 files changed, 24 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c
> > index 6fc0d1b89690..0ce8f4efc1ed 100644
> > --- a/drivers/gpu/drm/i915/i915_sw_fence.c
> > +++ b/drivers/gpu/drm/i915/i915_sw_fence.c
> > @@ -569,12 +569,11 @@ int __i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
> >  	return ret;
> >  }
> > -int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
> > -				    struct dma_resv *resv,
> > -				    const struct dma_fence_ops *exclude,
> > -				    bool write,
> > -				    unsigned long timeout,
> > -				    gfp_t gfp)
> > +int __i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
> > +				      struct dma_resv *resv,
> > +				      enum dma_resv_usage usage,
> > +				      unsigned long timeout,
> > +				      gfp_t gfp)
> >  {
> >  	struct dma_resv_iter cursor;
> >  	struct dma_fence *f;
> > @@ -583,7 +582,7 @@ int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
> >  	debug_fence_assert(fence);
> >  	might_sleep_if(gfpflags_allow_blocking(gfp));
> > -	dma_resv_iter_begin(&cursor, resv, dma_resv_usage_rw(write));
> > +	dma_resv_iter_begin(&cursor, resv, usage);
> >  	dma_resv_for_each_fence_unlocked(&cursor, f) {
> >  		pending = i915_sw_fence_await_dma_fence(fence, f, timeout,
> >  							gfp);
> > @@ -598,6 +597,18 @@ int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
> >  	return ret;
> >  }
> > +int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
> > +				    struct dma_resv *resv,
> > +				    const struct dma_fence_ops *exclude,
> > +				    bool write,
> > +				    unsigned long timeout,
> > +				    gfp_t gfp)
> > +{
> > +	return __i915_sw_fence_await_reservation(fence, resv,
> > +						 dma_resv_usage_rw(write),
> > +						 timeout, gfp);
> > +}
>
> Drive by observation - it looked dodgy that you create a wrapper here 
> which ignores one function parameter.
>
> On a more detailed look it seems no callers actually use exclude and 
> it's even unused inside this function since 1b5bdf071e62 ("drm/i915: 
> use the new iterator in i915_sw_fence_await_reservation v3").
>
> So a cleanup patch before this one?

Thanks Tvrtko.
Yah, I noticed it, but did not want to fix that here.
Sure, will post a patch beforehand to fix that.

Niranjana

> Regards,
>
> Tvrtko
>
>
> > +
> >  #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
> >  #include "selftests/lib_sw_fence.c"
> >  #include "selftests/i915_sw_fence.c"
> > diff --git a/drivers/gpu/drm/i915/i915_sw_fence.h b/drivers/gpu/drm/i915/i915_sw_fence.h
> > index 619fc5a22f0c..3cf4b6e16f35 100644
> > --- a/drivers/gpu/drm/i915/i915_sw_fence.h
> > +++ b/drivers/gpu/drm/i915/i915_sw_fence.h
> > @@ -10,13 +10,13 @@
> >  #define _I915_SW_FENCE_H_
> >  #include <linux/dma-fence.h>
> > +#include <linux/dma-resv.h>
> >  #include <linux/gfp.h>
> >  #include <linux/kref.h>
> >  #include <linux/notifier.h> /* for NOTIFY_DONE */
> >  #include <linux/wait.h>
> >  struct completion;
> > -struct dma_resv;
> >  struct i915_sw_fence;
> >  enum i915_sw_fence_notify {
> > @@ -89,6 +89,11 @@ int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
> >  				  unsigned long timeout,
> >  				  gfp_t gfp);
> > +int __i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
> > +				      struct dma_resv *resv,
> > +				      enum dma_resv_usage usage,
> > +				      unsigned long timeout,
> > +				      gfp_t gfp);
> >  int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
> >  				    struct dma_resv *resv,
> >  				    const struct dma_fence_ops *exclude,