drm/i915/kbl: Add WaClearSlmSpaceAtContextSwitch

This workaround for bdw and chv, is also needed for kbl A0.

References: HSD#1911519, BSID#569
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465309159-30531-24-git-send-email-mika.kuoppala@intel.com
(cherry picked from commit 066d462888514af727008a450f4078b1a23d5cbe)
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 3138d2f..7f2d841 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1275,6 +1275,7 @@ static int gen9_init_indirectctx_bb(struct intel_engine_cs *engine,
 {
        int ret;
        struct drm_device *dev = engine->dev;
+       struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t index = wa_ctx_start(wa_ctx, *offset, CACHELINE_DWORDS);
 
        /* WaDisableCtxRestoreArbitration:skl,bxt */
@@ -1288,6 +1289,22 @@ static int gen9_init_indirectctx_bb(struct intel_engine_cs *engine,
                return ret;
        index = ret;
 
+       /* WaClearSlmSpaceAtContextSwitch:kbl */
+       /* Actual scratch location is at 128 bytes offset */
+       if (IS_KBL_REVID(dev_priv, 0, KBL_REVID_A0)) {
+               uint32_t scratch_addr
+                       = engine->scratch.gtt_offset + 2*CACHELINE_BYTES;
+
+               wa_ctx_emit(batch, index, GFX_OP_PIPE_CONTROL(6));
+               wa_ctx_emit(batch, index, (PIPE_CONTROL_FLUSH_L3 |
+                                          PIPE_CONTROL_GLOBAL_GTT_IVB |
+                                          PIPE_CONTROL_CS_STALL |
+                                          PIPE_CONTROL_QW_WRITE));
+               wa_ctx_emit(batch, index, scratch_addr);
+               wa_ctx_emit(batch, index, 0);
+               wa_ctx_emit(batch, index, 0);
+               wa_ctx_emit(batch, index, 0);
+       }
        /* Pad to end of cacheline */
        while (index % CACHELINE_DWORDS)
                wa_ctx_emit(batch, index, MI_NOOP);