Commit 85fe9484 authored by Benjamin Franzke's avatar Benjamin Franzke 😀
Browse files

egl: Native Display autodetection



EGL doesnt define howto manage different native platforms.
So mesa has a builtime configurable default platform,
whith non-standard envvar (EGL_PLATFORM) overwrites.
This caused unneeded bugreports, when EGL_PLATFORM was forgotten.

Detection is grouped into basic types of NativeDisplays (which itself
needs to be detected).  The final decision is based on characteristcs
of these basic types:

  File Desciptor based platforms (fbdev):
    - fstat(2) to check for being a fd that belongs to a character device
    - check kernel subsystem (todo)

  Pointer to structuctures (x11, wayland, drm/gbm):
    - mincore(2) to check whether its valid pointer to some memory.
    - magic elements (e.g. pointers to exported symbols):
      o wayland display stores interface type pointer (first elm.)
      o gbm stores pointer to its constructor (first elm.)
      o x11 as a fallback (FIXME?)
Reviewed-by: Kristian H. Kristensen's avatarKristian Høgsberg <krh@bitplanet.net>
parent f5e757ea
......@@ -1370,6 +1370,8 @@ if test "x$enable_egl" = xyes; then
EGL_LIB_DEPS="$DLOPEN_LIBS $SELINUX_LIBS -lpthread"
EGL_DRIVERS_DIRS=""
AC_CHECK_FUNC(mincore, [DEFINES="$DEFINES -DHAVE_MINCORE"])
if test "$enable_static" != yes; then
# build egl_glx when libGL is built
if test "x$enable_glx" = xyes; then
......
......@@ -93,6 +93,19 @@ ifeq ($(firstword $(EGL_PLATFORMS)),fbdev)
EGL_NATIVE_PLATFORM=_EGL_PLATFORM_FBDEV
endif
ifneq ($(findstring x11, $(EGL_PLATFORMS)),)
LOCAL_CFLAGS += -DHAVE_X11_PLATFORM
endif
ifneq ($(findstring wayland, $(EGL_PLATFORMS)),)
LOCAL_CFLAGS += -DHAVE_WAYLAND_PLATFORM
endif
ifneq ($(findstring drm, $(EGL_PLATFORMS)),)
LOCAL_CFLAGS += -DHAVE_DRM_PLATFORM
endif
ifneq ($(findstring fbdev, $(EGL_PLATFORMS)),)
LOCAL_CFLAGS += -DHAVE_FBDEV_PLATFORM
endif
LOCAL_CFLAGS += \
-D_EGL_NATIVE_PLATFORM=$(EGL_NATIVE_PLATFORM) \
-D_EGL_DRIVER_SEARCH_DIR=\"$(EGL_DRIVER_INSTALL_DIR)\"
......
......@@ -301,7 +301,7 @@ _eglUnlockDisplay(_EGLDisplay *dpy)
EGLDisplay EGLAPIENTRY
eglGetDisplay(EGLNativeDisplayType nativeDisplay)
{
_EGLPlatformType plat = _eglGetNativePlatform();
_EGLPlatformType plat = _eglGetNativePlatform(nativeDisplay);
_EGLDisplay *dpy = _eglFindDisplay(plat, (void *) nativeDisplay);
return _eglGetDisplayHandle(dpy);
}
......@@ -538,7 +538,7 @@ eglCreateWindowSurface(EGLDisplay dpy, EGLConfig config,
EGLSurface ret;
_EGL_CHECK_CONFIG(disp, conf, EGL_NO_SURFACE, drv);
if (disp->Platform != _eglGetNativePlatform())
if (disp->Platform != _eglGetNativePlatform(disp->PlatformDisplay))
RETURN_EGL_ERROR(disp, EGL_BAD_NATIVE_WINDOW, EGL_NO_SURFACE);
surf = drv->API.CreateWindowSurface(drv, disp, conf, window, attrib_list);
......@@ -559,7 +559,7 @@ eglCreatePixmapSurface(EGLDisplay dpy, EGLConfig config,
EGLSurface ret;
_EGL_CHECK_CONFIG(disp, conf, EGL_NO_SURFACE, drv);
if (disp->Platform != _eglGetNativePlatform())
if (disp->Platform != _eglGetNativePlatform(disp->PlatformDisplay))
RETURN_EGL_ERROR(disp, EGL_BAD_NATIVE_PIXMAP, EGL_NO_SURFACE);
surf = drv->API.CreatePixmapSurface(drv, disp, conf, pixmap, attrib_list);
......@@ -720,7 +720,7 @@ eglCopyBuffers(EGLDisplay dpy, EGLSurface surface, EGLNativePixmapType target)
EGLBoolean ret;
_EGL_CHECK_SURFACE(disp, surf, EGL_FALSE, drv);
if (disp->Platform != _eglGetNativePlatform())
if (disp->Platform != _eglGetNativePlatform(disp->PlatformDisplay))
RETURN_EGL_ERROR(disp, EGL_BAD_NATIVE_PIXMAP, EGL_FALSE);
ret = drv->API.CopyBuffers(drv, disp, surf, target);
......
......@@ -43,6 +43,23 @@
#include "eglmutex.h"
#include "egllog.h"
/* Includes for _eglNativePlatformDetectNativeDisplay */
#ifdef HAVE_MINCORE
#include <unistd.h>
#include <sys/mman.h>
#endif
#ifdef HAVE_WAYLAND_PLATFORM
#include <wayland-client.h>
#endif
#ifdef HAVE_DRM_PLATFORM
#include <gbm.h>
#endif
#ifdef HAVE_FBDEV_PLATFORM
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#endif
/**
* Return the native platform by parsing EGL_PLATFORM.
......@@ -83,18 +100,95 @@ _eglGetNativePlatformFromEnv(void)
}
/**
* Perform validity checks on a generic pointer.
*/
static EGLBoolean
_eglPointerIsDereferencable(void *p)
{
#ifdef HAVE_MINCORE
uintptr_t addr = (uintptr_t) p;
unsigned char valid = 0;
const long page_size = getpagesize();
if (p == NULL)
return EGL_FALSE;
/* align addr to page_size */
addr &= ~(page_size - 1);
if (mincore((void *) addr, page_size, &valid) < 0) {
_eglLog(_EGL_DEBUG, "mincore failed: %m");
return EGL_FALSE;
}
return (valid & 0x01) == 0x01;
#else
return p != NULL;
#endif
}
/**
* Try detecting native platform with the help of native display characteristcs.
*/
static _EGLPlatformType
_eglNativePlatformDetectNativeDisplay(EGLNativeDisplayType nativeDisplay)
{
#ifdef HAVE_FBDEV_PLATFORM
struct stat buf;
#endif
if (nativeDisplay == EGL_DEFAULT_DISPLAY)
return _EGL_INVALID_PLATFORM;
#ifdef HAVE_FBDEV_PLATFORM
/* fbdev is the only platform that can be a file descriptor. */
if (fstat((intptr_t) nativeDisplay, &buf) == 0 && S_ISCHR(buf.st_mode))
return _EGL_PLATFORM_FBDEV;
#endif
if (_eglPointerIsDereferencable(nativeDisplay)) {
void *first_pointer = *(void **) nativeDisplay;
#ifdef HAVE_WAYLAND_PLATFORM
/* wl_display is a wl_proxy, which is a wl_object.
* wl_object's first element points to the interfacetype. */
if (first_pointer == &wl_display_interface)
return _EGL_PLATFORM_WAYLAND;
#endif
#ifdef HAVE_DRM_PLATFORM
/* gbm has a pointer to its constructor as first element. */
if (first_pointer == gbm_create_device)
return _EGL_PLATFORM_DRM;
#endif
#ifdef HAVE_X11_PLATFORM
/* If not matched to any other platform, fallback to x11. */
return _EGL_PLATFORM_X11;
#endif
}
return _EGL_INVALID_PLATFORM;
}
/**
* Return the native platform. It is the platform of the EGL native types.
*/
_EGLPlatformType
_eglGetNativePlatform(void)
_eglGetNativePlatform(EGLNativeDisplayType nativeDisplay)
{
static _EGLPlatformType native_platform = _EGL_INVALID_PLATFORM;
if (native_platform == _EGL_INVALID_PLATFORM) {
native_platform = _eglGetNativePlatformFromEnv();
if (native_platform == _EGL_INVALID_PLATFORM)
native_platform = _EGL_NATIVE_PLATFORM;
if (native_platform == _EGL_INVALID_PLATFORM) {
native_platform = _eglNativePlatformDetectNativeDisplay(nativeDisplay);
if (native_platform == _EGL_INVALID_PLATFORM)
native_platform = _EGL_NATIVE_PLATFORM;
}
}
return native_platform;
......
......@@ -150,7 +150,7 @@ struct _egl_display
extern _EGLPlatformType
_eglGetNativePlatform(void);
_eglGetNativePlatform(EGLNativeDisplayType nativeDisplay);
extern void
......
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