iris: Start wiring up on-disk shader cache

This creates the on-disk shader cache data structure, and handles the
build-id keying aspects.  The next commits will fill it out so it's
actually used.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/gallium/drivers/iris/iris_disk_cache.c

+/*
+ * Copyright © 2018 Intel Corporation
+ *
+ * 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 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.
+ */
+
+/**
+ * @file iris_disk_cache.c
+ *
+ * Functions for interacting with the on-disk shader cache.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <assert.h>
+#include <string.h>
+
+#include "compiler/blob.h"
+#include "compiler/nir/nir.h"
+#include "util/build_id.h"
+#include "util/disk_cache.h"
+#include "util/mesa-sha1.h"
+
+#include "iris_context.h"
+
+/**
+ * Initialize the on-disk shader cache.
+ */
+void
+iris_disk_cache_init(struct iris_screen *screen)
+{
+#ifdef ENABLE_SHADER_CACHE
+   if (INTEL_DEBUG & DEBUG_DISK_CACHE_DISABLE_MASK)
+      return;
+
+   /* array length = print length + nul char + 1 extra to verify it's unused */
+   char renderer[11];
+   UNUSED int len =
+      snprintf(renderer, sizeof(renderer), "iris_%04x", screen->pci_id);
+   assert(len == sizeof(renderer) - 2);
+
+   const struct build_id_note *note =
+      build_id_find_nhdr_for_addr(iris_disk_cache_init);
+   assert(note && build_id_length(note) == 20); /* sha1 */
+
+   const uint8_t *id_sha1 = build_id_data(note);
+   assert(id_sha1);
+
+   char timestamp[41];
+   _mesa_sha1_format(timestamp, id_sha1);
+
+   const uint64_t driver_flags =
+      brw_get_compiler_config_value(screen->compiler);
+   screen->disk_cache = disk_cache_create(renderer, timestamp, driver_flags);
+#endif
+}

src/gallium/drivers/iris/iris_screen.c

@@ -510,6 +510,7 @@ iris_destroy_screen(struct pipe_screen *pscreen)
    iris_bo_unreference(screen->workaround_bo);
    u_transfer_helper_destroy(pscreen->transfer_helper);
    iris_bufmgr_destroy(screen->bufmgr);
+   disk_cache_destroy(screen->disk_cache);
    ralloc_free(screen);
 }
 
@@ -637,6 +638,8 @@ iris_screen_create(int fd, const struct pipe_screen_config *config)
    screen->compiler->shader_perf_log = iris_shader_perf_log;
    screen->compiler->supports_pull_constants = false;
 
+   iris_disk_cache_init(screen);
+
    slab_create_parent(&screen->transfer_pool,
                       sizeof(struct iris_transfer), 64);
 

src/gallium/drivers/iris/iris_screen.h

@@ -25,6 +25,7 @@
 
 #include "pipe/p_screen.h"
 #include "state_tracker/drm_driver.h"
+#include "util/disk_cache.h"
 #include "util/slab.h"
 #include "util/u_screen.h"
 #include "intel/dev/gen_device_info.h"
@@ -80,6 +81,8 @@ struct iris_screen {
     * require scratch writes or reads from some unimportant memory.
     */
    struct iris_bo *workaround_bo;
+
+   struct disk_cache *disk_cache;
 };
 
 struct pipe_screen *
@@ -93,4 +96,6 @@ iris_is_format_supported(struct pipe_screen *pscreen,
                          unsigned storage_sample_count,
                          unsigned usage);
 
+void iris_disk_cache_init(struct iris_screen *screen);
+
 #endif

src/gallium/drivers/iris/meson.build

@@ -45,6 +45,7 @@ files_libiris = files(
   'iris_resource.h',
   'iris_screen.c',
   'iris_screen.h',
+  'iris_disk_cache.c',
 )
 
 iris_driinfo_h = custom_target(