DRI2: Allow building without libdrm

Some drivers use DRI protocol but implement their own kernel rendering
manager. For these drivers, libdrm becomes useless. --disable-libdrm
configure parameter can be used to disable libdrm support in dri2.

To provide ABI/API compatibility for libdrm based drivers, libdrm call
is wrapped in ifdef.

Signed-off-by: Tiago Vignatti <tiago.vignatti@nokia.com>
Signed-off-by: Pauli Nieminen <ext-pauli.nieminen@nokia.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>

configure.ac

@@ -644,6 +644,7 @@ AC_ARG_ENABLE(vgahw,          AS_HELP_STRING([--enable-vgahw], [Build Xorg with
 AC_ARG_ENABLE(vbe,            AS_HELP_STRING([--enable-vbe], [Build Xorg with VBE module (default: enabled)]), [VBE=$enableval], [VBE=yes])
 AC_ARG_ENABLE(int10-module,     AS_HELP_STRING([--enable-int10-module], [Build Xorg with int10 module (default: enabled)]), [INT10MODULE=$enableval], [INT10MODULE=yes])
 AC_ARG_ENABLE(windowswm,      AS_HELP_STRING([--enable-windowswm], [Build XWin with WindowsWM extension (default: no)]), [WINDOWSWM=$enableval], [WINDOWSWM=no])
+AC_ARG_ENABLE(libdrm,         AS_HELP_STRING([--enable-libdrm], [Build Xorg with libdrm support (default: enabled)]), [DRM=$enableval],[DRM=yes])
 
 dnl DDXes.
 AC_ARG_ENABLE(xorg,    	      AS_HELP_STRING([--enable-xorg], [Build Xorg server (default: auto)]), [XORG=$enableval], [XORG=auto])
@@ -1033,9 +1034,10 @@ esac
 AM_CONDITIONAL(DRI2, test "x$DRI2" = xyes)
 
 if test "x$DRI" = xyes || test "x$DRI2" = xyes; then
+	if test "x$DRM" = xyes; then
+		AC_DEFINE(WITH_LIBDRM, 1, [Building with libdrm support])
 		PKG_CHECK_MODULES([LIBDRM], $LIBDRM)
-	AC_SUBST(LIBDRM_CFLAGS)
+	fi
-	AC_SUBST(LIBDRM_LIBS)
 fi
 
 if test "x$DRI2" = xyes; then

hw/xfree86/dri2/dri2.c

@@ -35,7 +35,9 @@
 #endif
 
 #include <errno.h>
+#ifdef WITH_LIBDRM
 #include <xf86drm.h>
+#endif
 #include "xf86Module.h"
 #include "list.h"
 #include "scrnintstr.h"
@@ -965,7 +967,7 @@ DRI2Connect(ScreenPtr pScreen, unsigned int driverType, int *fd,
 }
 
 Bool
-DRI2Authenticate(ScreenPtr pScreen, drm_magic_t magic)
+DRI2Authenticate(ScreenPtr pScreen, uint32_t magic)
 {
     DRI2ScreenPtr ds = DRI2GetScreen(pScreen);
 
@@ -1045,9 +1047,16 @@ DRI2ScreenInit(ScreenPtr pScreen, DRI2InfoPtr info)
         ds->AuthMagic = info->AuthMagic;
     }
 
+    /*
+     * if the driver doesn't provide an AuthMagic function or the info struct
+     * version is too low, it relies on the old method (using libdrm) or fail
+     */
     if (!ds->AuthMagic)
+#ifdef WITH_LIBDRM
         ds->AuthMagic = drmAuthMagic;
-
+#else
+        goto err_out;
+#endif
 
     /* Initialize minor if needed and set to minimum provied by DDX */
     if (!dri2_minor || dri2_minor > cur_minor)
@@ -1087,6 +1096,12 @@ DRI2ScreenInit(ScreenPtr pScreen, DRI2InfoPtr info)
     }
 
     return TRUE;
+
+err_out:
+    xf86DrvMsg(pScreen->myNum, X_WARNING,
+            "[DRI2] Initialization failed for info version %d.\n", info->version);
+    free(ds);
+    return FALSE;
 }
 
 void

hw/xfree86/dri2/dri2.h

@@ -206,7 +206,7 @@ extern _X_EXPORT Bool DRI2Connect(ScreenPtr pScreen,
 		 const char **driverName,
 		 const char **deviceName);
 
-extern _X_EXPORT Bool DRI2Authenticate(ScreenPtr pScreen, drm_magic_t magic);
+extern _X_EXPORT Bool DRI2Authenticate(ScreenPtr pScreen, uint32_t magic);
 
 extern _X_EXPORT int DRI2CreateDrawable(ClientPtr client,
 					DrawablePtr pDraw,

hw/xfree86/dri2/dri2ext.c

@@ -42,7 +42,6 @@
 #include "scrnintstr.h"
 #include "pixmapstr.h"
 #include "extnsionst.h"
-#include "xf86drm.h"
 #include "xfixes.h"
 #include "dri2.h"
 #include "protocol-versions.h"

include/xorg-config.h.in

@@ -139,4 +139,7 @@
 /* Support PC98 */
 #undef SUPPORT_PC98
 
+/* Build with libdrm support */
+#undef WITH_LIBDRM
+
 #endif /* _XORG_CONFIG_H_ */