wsi: Load ICD and dispatch ICD functions

Return ICD functions in vk_icdGetInstanceProcAddr() if there's no our
implementation for that name.

Change-Id: I5297f2bf9c6d7ffbf272b8e33c63b394b2dfd23d

diff --git a/src/wsi/entry-points.c b/src/wsi/entry-points.c
index fc2de54..46ce175 100644 (file)
--- a/src/wsi/entry-points.c
+++ b/src/wsi/entry-points.c
@@ -24,11 +24,14 @@
 
 #include "wsi.h"
 #include <string.h>
+#include <stdlib.h>
+#include <dlfcn.h>
 
 #define VK_ENTRY_POINT(name, type) { "vk"#name, vk_##name, VK_FUNC_TYPE_##type }
 
-typedef enum vk_func_type      vk_func_type_t;
-typedef struct vk_entry                vk_entry_t;
+typedef enum vk_func_type              vk_func_type_t;
+typedef struct vk_entry                        vk_entry_t;
+typedef struct vk_icd_loader   vk_icd_loader_t;
 
 enum vk_func_type {
        VK_FUNC_TYPE_GLOBAL,
@@ -42,6 +45,11 @@ struct vk_entry {
        vk_func_type_t   type;
 };
 
+struct vk_icd_loader {
+       void                                            *lib;
+       PFN_vkGetInstanceProcAddr        gpa;
+};
+
 static const vk_entry_t        entry_points[] = {
        VK_ENTRY_POINT(DestroySurfaceKHR, INSTANCE),
        VK_ENTRY_POINT(GetPhysicalDeviceSurfaceSupportKHR, INSTANCE),
@@ -93,6 +101,32 @@ get_entry_point(const char *name)
        return NULL;
 }
 
+static vk_icd_loader_t icd;
+
+static void __attribute__((constructor))
+icd_init(void)
+{
+       const char *filename;
+
+       filename = getenv("VK_TIZEN_ICD");
+       VK_CHECK(filename, return, "No ICD library given.\n");
+
+       dlerror();
+
+       icd.lib = dlopen(filename, RTLD_LAZY | RTLD_LOCAL);
+       VK_CHECK(icd.lib, return, "dlopen() failed - %s\n", dlerror());
+
+       icd.gpa = dlsym(icd.lib, "vk_icdGetInstanceProcAddr");
+       VK_CHECK(icd.gpa, return, "vk_icdGetInstanceProcAddr() not present.\n");
+}
+
+static void __attribute__((destructor))
+icd_fini(void)
+{
+       if (icd.lib)
+               dlclose(icd.lib);
+}
+
 VK_EXPORT VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL
 vk_icdGetInstanceProcAddr(VkInstance instance, const char *name)
 {
@@ -101,5 +135,5 @@ vk_icdGetInstanceProcAddr(VkInstance instance, const char *name)
        if (entry)
                return entry->func;
 
-       return NULL;
+       return icd.gpa(instance, name);
 }