Merge tag 'Intel-CVE-2019-14615' from bundle by Akeem Abodunrin.

Merge Intel Gen9 graphics fix from Akeem Abodunrin:
 "Insufficient control flow in certain data structures for some Intel
  Processors with Intel Processor Graphics may allow an unauthenticated
  user to potentially enable information disclosure via local access

  This provides mitigation for Gen9 hardware. Note that Gen8 is not
  impacted due to a previously implemented workaround.

  The mitigation involves using an existing hardware feature to forcibly
  clear down all EU state at each context switch"

* tag 'Intel-CVE-2019-14615' of emailed bundle from Akeem G Abodunrin <akeem.g.abodunrin@intel.com>:
  drm/i915/gen9: Clear residual context state on context switch

drivers/gpu/drm/i915/gt/intel_lrc.c

@@ -2664,6 +2664,14 @@ static u32 *gen9_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch)
 	/* WaFlushCoherentL3CacheLinesAtContextSwitch:skl,bxt,glk */
 	batch = gen8_emit_flush_coherentl3_wa(engine, batch);
 
+	/* WaClearSlmSpaceAtContextSwitch:skl,bxt,kbl,glk,cfl */
+	batch = gen8_emit_pipe_control(batch,
+				       PIPE_CONTROL_FLUSH_L3 |
+				       PIPE_CONTROL_STORE_DATA_INDEX |
+				       PIPE_CONTROL_CS_STALL |
+				       PIPE_CONTROL_QW_WRITE,
+				       LRC_PPHWSP_SCRATCH_ADDR);
+
 	batch = emit_lri(batch, lri, ARRAY_SIZE(lri));
 
 	/* WaMediaPoolStateCmdInWABB:bxt,glk */