We've lost our guard page somewhere in the gtt rewrite, this patch here will restore it. Exercised by i-g-t/tests/gem_cs_prefetch. v2: Substract the guard page from the range we're supposed to manage with gem. Suggested by Chris Wilson to increase the odds of old ums + gem userspace not blowing up. To compensate for the loss of a page, don't substract the guard page in the modeset init code any longer. Tested-by: Chris Wilson <chris at chris-wilson.co.uk> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44748 Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch> --- drivers/gpu/drm/i915/i915_dma.c | 4 +--- drivers/gpu/drm/i915/i915_gem_gtt.c | 5 +++-- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index c2d9eae..4f690374 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -1207,8 +1207,6 @@ static int i915_load_gem_init(struct drm_device *dev) /* PPGTT pdes are stolen from global gtt ptes, so shrink the * aperture accordingly when using aliasing ppgtt. */ gtt_size -= I915_PPGTT_PD_ENTRIES*PAGE_SIZE; - /* For paranoia keep the guard page in between. */ - gtt_size -= PAGE_SIZE; i915_gem_init_global_gtt(dev, 0, mappable_size, gtt_size); @@ -1227,7 +1225,7 @@ static int i915_load_gem_init(struct drm_device *dev) * aperture. */ i915_gem_init_global_gtt(dev, 0, mappable_size, - gtt_size - PAGE_SIZE); + gtt_size); } ret = i915_gem_init_hw(dev); diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 98ed612..5a626f7 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -429,7 +429,8 @@ void i915_gem_init_global_gtt(struct drm_device *dev, { drm_i915_private_t *dev_priv = dev->dev_private; - drm_mm_init(&dev_priv->mm.gtt_space, start, end - start); + /* Substract the guard page ... */ + drm_mm_init(&dev_priv->mm.gtt_space, start, end - start - PAGE_SIZE); dev_priv->mm.gtt_start = start; dev_priv->mm.gtt_mappable_end = mappable_end; @@ -437,6 +438,6 @@ void i915_gem_init_global_gtt(struct drm_device *dev, dev_priv->mm.gtt_total = end - start; dev_priv->mm.mappable_gtt_total = min(end, mappable_end) - start; - /* Take over this portion of the GTT */ + /* ... but ensure that we clear the entire range. */ intel_gtt_clear_range(start / PAGE_SIZE, (end-start) / PAGE_SIZE); } -- 1.7.8.3
