intel: verify if hardware has LLC support

Rely on libdrm HAS_LLC parameter to verify if hardware supports it. In
case the libdrm version does not supports this check, fallback to older
way of detecting it which assumed that GPUs newer than GEN6 have it.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>

src/mesa/drivers/dri/intel/intel_context.c

@@ -628,6 +628,7 @@ intelInitContext(struct intel_context *intel,
    intel->has_separate_stencil = intel->intelScreen->hw_has_separate_stencil;
    intel->must_use_separate_stencil = intel->intelScreen->hw_must_use_separate_stencil;
    intel->has_hiz = intel->intelScreen->hw_has_hiz;
+   intel->has_llc = intel->intelScreen->hw_has_llc;
 
    memset(&ctx->TextureFormatSupported,
 	  0, sizeof(ctx->TextureFormatSupported));

src/mesa/drivers/dri/intel/intel_context.h

@@ -213,6 +213,7 @@ struct intel_context
    bool has_separate_stencil;
    bool must_use_separate_stencil;
    bool has_hiz;
+   bool has_llc;
 
    int urb_size;
 

src/mesa/drivers/dri/intel/intel_screen.c

@@ -735,6 +735,14 @@ __DRIconfig **intelInitScreen2(__DRIscreen *psp)
    intelScreen->hw_has_hiz = intelScreen->gen >= 6;
    intelScreen->dri2_has_hiz = INTEL_DRI2_HAS_HIZ_UNKNOWN;
 
+#if defined(I915_PARAM_HAS_LLC)
+   intelScreen->hw_has_llc =
+      intel_get_boolean(intelScreen->driScrnPriv,
+              I915_PARAM_HAS_LLC);
+#else
+   intelScreen->hw_has_llc = intelScreen->gen >= 6;
+#endif
+
    intel_override_hiz(intelScreen);
    intel_override_separate_stencil(intelScreen);
 

src/mesa/drivers/dri/intel/intel_screen.h

@@ -116,6 +116,8 @@ struct intel_screen
 
    bool kernel_has_gen7_sol_reset;
 
+   bool hw_has_llc;
+
    bool no_vbo;
    dri_bufmgr *bufmgr;
    struct _mesa_HashTable *named_regions;