If FBC is set on a framebuffer that is unmapped, all GTT faults will be
from a partial mapping. Writes by the user through the partial VMA are
then untracked by the FBC and so we must use the ORIGIN_CPU when flushing
the I915_GEM_DOMAIN_GTT.
v2: Keep ORIGIN_CPU for set-to-domain(.write=CPU)
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Cc: "Zanoni, Paulo R" <paulo.r.zanoni@xxxxxxxxx>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_drv.h | 2 +-
drivers/gpu/drm/i915/i915_gem.c | 12 +++++++++---
2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 56d439374fe5..9386523464ea 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2198,6 +2198,7 @@ struct drm_i915_gem_object {
unsigned int cache_dirty:1;
atomic_t frontbuffer_bits;
+ unsigned int frontbuffer_ggtt_origin; /* write once */
/** Current tiling stride for the object, if it's tiled. */
unsigned int tiling_and_stride;
@@ -2205,7 +2206,6 @@ struct drm_i915_gem_object {
#define TILING_MASK (FENCE_MINIMUM_STRIDE-1)
#define STRIDE_MASK (~TILING_MASK)
- unsigned int has_wc_mmap;
/** Count of VMA actually bound by this object */
unsigned int bind_count;
unsigned int pin_display;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e4c18c71576f..9811980d6837 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1497,8 +1497,8 @@ err:
static inline enum fb_op_origin
write_origin(struct drm_i915_gem_object *obj, unsigned domain)
{
- return domain == I915_GEM_DOMAIN_GTT && !obj->has_wc_mmap ?
- ORIGIN_GTT : ORIGIN_CPU;
+ return (domain == I915_GEM_DOMAIN_GTT ?
+ obj->frontbuffer_ggtt_origin : ORIGIN_CPU);
}
/**
@@ -1658,7 +1658,7 @@ i915_gem_mmap_ioctl(struct drm_device *dev, void *data,
up_write(&mm->mmap_sem);
/* This may race, but that's ok, it only gets set */
- WRITE_ONCE(obj->has_wc_mmap, true);
+ WRITE_ONCE(obj->frontbuffer_ggtt_origin, ORIGIN_CPU);
}
i915_gem_object_put_unlocked(obj);
if (IS_ERR((void *)addr))
@@ -1761,6 +1761,11 @@ int i915_gem_fault(struct vm_area_struct *area, struct vm_fault *vmf)
if (chunk_size >= obj->base.size >> PAGE_SHIFT)
view.type = I915_GGTT_VIEW_NORMAL;
+ /* Userspace is now writing through an untracked VMA, abandon
+ * all hope that the hardware is able to track future writes.
+ */
+ obj->frontbuffer_ggtt_origin = ORIGIN_CPU;
+
vma = i915_gem_object_ggtt_pin(obj, &view, 0, 0, PIN_MAPPABLE);
}
if (IS_ERR(vma)) {
@@ -4093,6 +4098,7 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj,
obj->ops = ops;
+ obj->frontbuffer_ggtt_origin = ORIGIN_GTT;
obj->madv = I915_MADV_WILLNEED;
i915_gem_info_add_obj(to_i915(obj->base.dev), obj->base.size);
--
2.9.3
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
