vc4: Add the necessary stubs for occlusion queries.

We have to expose them for GL 2.0, but we just always return a value of 0.
We should be advertising 0 query bits instead of 64, but gallium doesn't
have plumbing for that yet.  At least this stops the segfaults.

src/gallium/drivers/vc4/Makefile.sources

@@ -24,6 +24,7 @@ C_SOURCES := \
 	vc4_qpu_emit.c \
 	vc4_qpu.h \
 	vc4_qpu_validate.c \
+	vc4_query.c \
 	vc4_register_allocate.c \
 	vc4_reorder_uniforms.c \
 	vc4_resource.c \

src/gallium/drivers/vc4/vc4_context.c

@@ -368,6 +368,7 @@ vc4_context_create(struct pipe_screen *pscreen, void *priv)
         vc4_draw_init(pctx);
         vc4_state_init(pctx);
         vc4_program_init(pctx);
+        vc4_query_init(pctx);
         vc4_resource_context_init(pctx);
 
         vc4_init_cl(vc4, &vc4->bcl);

src/gallium/drivers/vc4/vc4_context.h

@@ -244,6 +244,7 @@ struct pipe_context *vc4_context_create(struct pipe_screen *pscreen,
 void vc4_draw_init(struct pipe_context *pctx);
 void vc4_state_init(struct pipe_context *pctx);
 void vc4_program_init(struct pipe_context *pctx);
+void vc4_query_init(struct pipe_context *pctx);
 void vc4_simulator_init(struct vc4_screen *screen);
 int vc4_simulator_flush(struct vc4_context *vc4,
                         struct drm_vc4_submit_cl *args);
@@ -266,5 +267,5 @@ bool vc4_rt_format_is_565(enum pipe_format f);
 bool vc4_tex_format_supported(enum pipe_format f);
 uint8_t vc4_get_tex_format(enum pipe_format f);
 const uint8_t *vc4_get_format_swizzle(enum pipe_format f);
-
+void vc4_init_query_functions(struct vc4_context *vc4);
 #endif /* VC4_CONTEXT_H */

src/gallium/drivers/vc4/vc4_query.c

@@ -0,0 +1,83 @@
+/*
+ * Copyright © 2014 Broadcom
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+/**
+ * Stub support for occlusion queries.
+ *
+ * Since we expose support for GL 2.0, we have to expose occlusion queries,
+ * but the spec allows you to expose 0 query counter bits, so we just return 0
+ * as the result of all our queries.
+ */
+#include "vc4_context.h"
+
+struct vc4_query
+{
+        uint8_t pad;
+};
+
+static struct pipe_query *
+vc4_create_query(struct pipe_context *ctx, unsigned query_type, unsigned index)
+{
+        struct vc4_query *query = calloc(1, sizeof(*query));
+
+        /* Note that struct pipe_query isn't actually defined anywhere. */
+        return (struct pipe_query *)query;
+}
+
+static void
+vc4_destroy_query(struct pipe_context *ctx, struct pipe_query *query)
+{
+        free(query);
+}
+
+static void
+vc4_begin_query(struct pipe_context *ctx, struct pipe_query *query)
+{
+}
+
+static void
+vc4_end_query(struct pipe_context *ctx, struct pipe_query *query)
+{
+}
+
+static boolean
+vc4_get_query_result(struct pipe_context *ctx, struct pipe_query *query,
+                     boolean wait, union pipe_query_result *vresult)
+{
+        uint64_t *result = &vresult->u64;
+
+        *result = 0;
+
+        return true;
+}
+
+void
+vc4_query_init(struct pipe_context *pctx)
+{
+        pctx->create_query = vc4_create_query;
+        pctx->destroy_query = vc4_destroy_query;
+        pctx->begin_query = vc4_begin_query;
+        pctx->end_query = vc4_end_query;
+        pctx->get_query_result = vc4_get_query_result;
+}
+