obj->pin_global was original used as a means to keep the shrinker off the active scanout, but we use the vma->pin_count itself for that and the obj->frontbuffer to delay shrinking active framebuffers. The other role that obj->pin_global gained was for spotting display objects inside GEM and working harder to keep those coherent; for which we can again simply inspect obj->frontbuffer directly.
Coming up next, we will want to manipulate the pin_global counter outside of the principle locks, so would need to make pin_global atomic. However, since obj->frontbuffer is already managed atomically, it makes sense to use that the primary key for display objects instead of having pin_global. Signed-off-by: Chris Wilson <[email protected]> Cc: Mika Kuoppala <[email protected]> --- .../gpu/drm/i915/display/intel_frontbuffer.c | 13 +++++-- drivers/gpu/drm/i915/gem/i915_gem_domain.c | 34 ++++++------------- drivers/gpu/drm/i915/gem/i915_gem_object.h | 3 +- .../gpu/drm/i915/gem/i915_gem_object_types.h | 2 -- drivers/gpu/drm/i915/gem/i915_gem_shrinker.c | 15 +++----- drivers/gpu/drm/i915/i915_debugfs.c | 12 ++----- 6 files changed, 29 insertions(+), 50 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.c b/drivers/gpu/drm/i915/display/intel_frontbuffer.c index 719379774fa5..fc40dc1fdbcc 100644 --- a/drivers/gpu/drm/i915/display/intel_frontbuffer.c +++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.c @@ -220,11 +220,18 @@ static void frontbuffer_release(struct kref *ref) { struct intel_frontbuffer *front = container_of(ref, typeof(*front), ref); + struct drm_i915_gem_object *obj = front->obj; + struct i915_vma *vma; - front->obj->frontbuffer = NULL; - spin_unlock(&to_i915(front->obj->base.dev)->fb_tracking.lock); + spin_lock(&obj->vma.lock); + for_each_ggtt_vma(vma, obj) + vma->display_alignment = I915_GTT_MIN_ALIGNMENT; + spin_unlock(&obj->vma.lock); - i915_gem_object_put(front->obj); + obj->frontbuffer = NULL; + spin_unlock(&to_i915(obj->base.dev)->fb_tracking.lock); + + i915_gem_object_put(obj); kfree(front); } diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c b/drivers/gpu/drm/i915/gem/i915_gem_domain.c index 9c58e8fac1d9..0341b3da930a 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_domain.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c @@ -27,7 +27,7 @@ static void __i915_gem_object_flush_for_display(struct drm_i915_gem_object *obj) void i915_gem_object_flush_if_display(struct drm_i915_gem_object *obj) { - if (!READ_ONCE(obj->pin_global)) + if (!READ_ONCE(obj->frontbuffer)) return; i915_gem_object_lock(obj); @@ -422,12 +422,8 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj, assert_object_held(obj); - /* Mark the global pin early so that we account for the - * display coherency whilst setting up the cache domains. - */ - obj->pin_global++; - - /* The display engine is not coherent with the LLC cache on gen6. As + /* + * The display engine is not coherent with the LLC cache on gen6. As * a result, we make sure that the pinning that is about to occur is * done with uncached PTEs. This is lowest common denominator for all * chipsets. @@ -439,12 +435,11 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj, ret = i915_gem_object_set_cache_level(obj, HAS_WT(to_i915(obj->base.dev)) ? I915_CACHE_WT : I915_CACHE_NONE); - if (ret) { - vma = ERR_PTR(ret); - goto err_unpin_global; - } + if (ret) + return ERR_PTR(ret); - /* As the user may map the buffer once pinned in the display plane + /* + * As the user may map the buffer once pinned in the display plane * (e.g. libkms for the bootup splash), we have to ensure that we * always use map_and_fenceable for all scanout buffers. However, * it may simply be too big to fit into mappable, in which case @@ -461,22 +456,19 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj, if (IS_ERR(vma)) vma = i915_gem_object_ggtt_pin(obj, view, 0, alignment, flags); if (IS_ERR(vma)) - goto err_unpin_global; + return vma; vma->display_alignment = max_t(u64, vma->display_alignment, alignment); __i915_gem_object_flush_for_display(obj); - /* It should now be out of any other write domains, and we can update + /* + * It should now be out of any other write domains, and we can update * the domain values for our changes. */ obj->read_domains |= I915_GEM_DOMAIN_GTT; return vma; - -err_unpin_global: - obj->pin_global--; - return vma; } static void i915_gem_object_bump_inactive_ggtt(struct drm_i915_gem_object *obj) @@ -514,12 +506,6 @@ i915_gem_object_unpin_from_display_plane(struct i915_vma *vma) assert_object_held(obj); - if (WARN_ON(obj->pin_global == 0)) - return; - - if (--obj->pin_global == 0) - vma->display_alignment = I915_GTT_MIN_ALIGNMENT; - /* Bump the LRU to try and avoid premature eviction whilst flipping */ i915_gem_object_bump_inactive_ggtt(obj); diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h index 5efb9936e05b..d6005cad9d5c 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h @@ -406,7 +406,8 @@ static inline bool cpu_write_needs_clflush(struct drm_i915_gem_object *obj) if (!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE)) return true; - return obj->pin_global; /* currently in use by HW, keep flushed */ + /* Currently in use by HW (display engine)? Keep flushed. */ + return READ_ONCE(obj->frontbuffer); } static inline void __start_cpu_write(struct drm_i915_gem_object *obj) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h index ede0eb4218a8..13b9dc0e1a89 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h +++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h @@ -152,8 +152,6 @@ struct drm_i915_gem_object { /** Count of VMA actually bound by this object */ atomic_t bind_count; - /** Count of how many global VMA are currently pinned for use by HW */ - unsigned int pin_global; struct { struct mutex lock; /* protects the pages and their use */ diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c index edd21d14e64f..4e55cfc2b0dc 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c @@ -61,7 +61,8 @@ static bool can_release_pages(struct drm_i915_gem_object *obj) if (!i915_gem_object_is_shrinkable(obj)) return false; - /* Only report true if by unbinding the object and putting its pages + /* + * Only report true if by unbinding the object and putting its pages * we can actually make forward progress towards freeing physical * pages. * @@ -72,16 +73,8 @@ static bool can_release_pages(struct drm_i915_gem_object *obj) if (atomic_read(&obj->mm.pages_pin_count) > atomic_read(&obj->bind_count)) return false; - /* If any vma are "permanently" pinned, it will prevent us from - * reclaiming the obj->mm.pages. We only allow scanout objects to claim - * a permanent pin, along with a few others like the context objects. - * To simplify the scan, and to avoid walking the list of vma under the - * object, we just check the count of its permanently pinned. - */ - if (READ_ONCE(obj->pin_global)) - return false; - - /* We can only return physical pages to the system if we can either + /* + * We can only return physical pages to the system if we can either * discard the contents (because the user has marked them as being * purgeable) or if we can move their contents out to swap. */ diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index e103fcba6435..b90371844689 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -77,11 +77,6 @@ static int i915_capabilities(struct seq_file *m, void *data) return 0; } -static char get_pin_flag(struct drm_i915_gem_object *obj) -{ - return obj->pin_global ? 'p' : ' '; -} - static char get_tiling_flag(struct drm_i915_gem_object *obj) { switch (i915_gem_object_get_tiling(obj)) { @@ -140,9 +135,8 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj) struct i915_vma *vma; int pin_count = 0; - seq_printf(m, "%pK: %c%c%c%c %8zdKiB %02x %02x %s%s%s", + seq_printf(m, "%pK: %c%c%c %8zdKiB %02x %02x %s%s%s", &obj->base, - get_pin_flag(obj), get_tiling_flag(obj), get_global_flag(obj), get_pin_mapped_flag(obj), @@ -221,8 +215,8 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj) seq_printf(m, " (pinned x %d)", pin_count); if (obj->stolen) seq_printf(m, " (stolen: %08llx)", obj->stolen->start); - if (obj->pin_global) - seq_printf(m, " (global)"); + if (READ_ONCE(obj->frontbuffer)) + seq_printf(m, " (front)"); engine = i915_gem_object_last_write_engine(obj); if (engine) -- 2.23.0 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
