@@ -171,13 +171,44 @@ static int gen6_ppgtt_enable(struct i915_hw_ppgtt *ppgtt)
/* GFX_MODE is per-ring on gen7+ */
}
+ POSTING_READ(GAM_ECOCHK);
for_each_ring(ring, dev_priv, i) {
+ int ret;
+
if (INTEL_INFO(dev)->gen >= 7)
I915_WRITE(RING_MODE_GEN7(ring),
_MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
- I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
- I915_WRITE(RING_PP_DIR_BASE(ring), pd_offset);
+ /* If we're in reset, we can assume the GPU is sufficiently idle
+ * to manually frob these bits. Ideally we could use the ring
+ * functions, except our error handling makes it quite difficult
+ * (can't use intel_ring_begin, ring->flush, or
+ * intel_ring_advance)
+ */
+ if (i915_reset_in_progress(&dev_priv->gpu_error)) {
+ WARN_ON(ppgtt != dev_priv->gtt.aliasing_ppgtt);
+ I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
+ I915_WRITE(RING_PP_DIR_BASE(ring), pd_offset);
+ return 0;
+ }
+
+ /* NB: TLBs must be flushed and invalidated before a switch */
+ ret = ring->flush(ring, I915_GEM_GPU_DOMAINS,
+ I915_GEM_GPU_DOMAINS);
+ if (ret)
+ return ret;
+
+ ret = intel_ring_begin(ring, 6);
+ if (ret)
+ return ret;
+
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(2));
+ intel_ring_emit(ring, RING_PP_DIR_DCLV(ring));
+ intel_ring_emit(ring, PP_DIR_DCLV_2G);
+ intel_ring_emit(ring, RING_PP_DIR_BASE(ring));
+ intel_ring_emit(ring, pd_offset);
+ intel_ring_emit(ring, MI_NOOP);
+ intel_ring_advance(ring);
}
return 0;
}
The docs seem to suggest this is the appropriate method (though it doesn't say so outright). We certainly must do this for switching VMs on the fly, since synchronizing the rings to MMIO updates isn't acceptable. Signed-off-by: Ben Widawsky <ben@bwidawsk.net> --- drivers/gpu/drm/i915/i915_gem_gtt.c | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-)