glamor: add glvnd_vendor private

This commit adds an ability to store a glvnd vendor in Glamor
structures, which can be used for initialize some vendor-based values
without hooking into DDX internals. Also this adds setting this value
into Xorg and Xwayland

Signed-off-by: Konstantin Pugin <ria.freelander@gmail.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Acked-by: Emma Anholt <emma@anholt.net>
(cherry picked from commit 3caf7aa88d)

Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1636>

glamor/glamor.c

@@ -964,6 +964,7 @@ glamor_close_screen(ScreenPtr screen)
     glamor_priv = glamor_get_screen_private(screen);
     glamor_sync_close(screen);
     glamor_composite_glyphs_fini(screen);
+    glamor_set_glvnd_vendor(screen, NULL);
     screen->CloseScreen = glamor_priv->saved_procs.close_screen;
 
     screen->CreateGC = glamor_priv->saved_procs.create_gc;
@@ -996,6 +997,31 @@ glamor_fini(ScreenPtr screen)
     /* Do nothing currently. */
 }
 
+void
+glamor_set_glvnd_vendor(ScreenPtr screen, const char *vendor_name)
+{
+    glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
+
+    if (!glamor_priv)
+        return;
+
+    if (glamor_priv->glvnd_vendor)
+        free(glamor_priv->glvnd_vendor);
+
+    glamor_priv->glvnd_vendor = xnfstrdup(vendor_name);
+}
+
+const char *
+glamor_get_glvnd_vendor(ScreenPtr screen)
+{
+    glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
+
+    if (!glamor_priv)
+        return NULL;
+
+    return glamor_priv->glvnd_vendor;
+}
+
 void
 glamor_enable_dri3(ScreenPtr screen)
 {

glamor/glamor.h

@@ -120,6 +120,12 @@ extern _X_EXPORT void glamor_clear_pixmap(PixmapPtr pixmap);
 
 extern _X_EXPORT void glamor_block_handler(ScreenPtr screen);
 
+/* This function should be called after glamor_init,
+ * but before adding a glamor GLX provider */
+extern _X_EXPORT void glamor_set_glvnd_vendor(ScreenPtr screen,
+                                              const char *vendor);
+extern _X_EXPORT const char *glamor_get_glvnd_vendor(ScreenPtr screen);
+
 extern _X_EXPORT PixmapPtr glamor_create_pixmap(ScreenPtr screen, int w, int h,
                                                 int depth, unsigned int usage);
 extern _X_EXPORT Bool glamor_destroy_pixmap(PixmapPtr pixmap);

glamor/glamor_egl.c

@@ -887,6 +887,7 @@ glamor_egl_screen_init(ScreenPtr screen, struct glamor_context *glamor_ctx)
 #ifdef DRI3
     glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
 #endif
+    const char *gbm_backend_name;
 
     glamor_egl->saved_close_screen = screen->CloseScreen;
     screen->CloseScreen = glamor_egl_close_screen;
@@ -899,6 +900,10 @@ glamor_egl_screen_init(ScreenPtr screen, struct glamor_context *glamor_ctx)
 
     glamor_ctx->make_current = glamor_egl_make_current;
 
+    gbm_backend_name = gbm_device_get_backend_name(glamor_egl->gbm);
+    /* Mesa uses "drm" as backend name, in that case, just do nothing */
+    if (gbm_backend_name && strcmp(gbm_backend_name, "drm") != 0)
+        glamor_set_glvnd_vendor(screen, gbm_backend_name);
 #ifdef DRI3
     /* Tell the core that we have the interfaces for import/export
      * of pixmaps.

glamor/glamor_priv.h

@@ -335,6 +335,7 @@ typedef struct glamor_screen_private {
     int flags;
     ScreenPtr screen;
     int dri3_enabled;
+    char *glvnd_vendor;
 
     Bool suppress_gl_out_of_memory_logging;
     Bool logged_any_fbo_allocation_failure;