src/egl/main/egldriver.c

   1 /**
   2  * Functions for choosing and opening/loading device drivers.
   3  */
   4
   5
   6 #include <assert.h>
   7 #include <string.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10
  11 #include "eglstring.h"
  12 #include "eglconfig.h"
  13 #include "eglcontext.h"
  14 #include "egldefines.h"
  15 #include "egldisplay.h"
  16 #include "egldriver.h"
  17 #include "eglglobals.h"
  18 #include "egllog.h"
  19 #include "eglmisc.h"
  20 #include "eglmode.h"
  21 #include "eglscreen.h"
  22 #include "eglstring.h"
  23 #include "eglsurface.h"
  24 #include "eglimage.h"
  25
  26 #if defined(_EGL_PLATFORM_POSIX)
  27 #include <dlfcn.h>
  28 #include <sys/types.h>
  29 #include <dirent.h>
  30 #include <unistd.h>
  31 #endif
  32
  33
  34 /**
  35  * Wrappers for dlopen/dlclose()
  36  */
  37 #if defined(_EGL_PLATFORM_WINDOWS)
  38
  39
  40 /* XXX Need to decide how to do dynamic name lookup on Windows */
  41 static const char *DefaultDriverNames[] = {
  42    "egl_gdi_swrast"
  43 };
  44
  45 typedef HMODULE lib_handle;
  46
  47 static HMODULE
  48 open_library(const char *filename)
  49 {
  50    return LoadLibrary(filename);
  51 }
  52
  53 static void
  54 close_library(HMODULE lib)
  55 {
  56    FreeLibrary(lib);
  57 }
  58
  59
  60 static const char *
  61 library_suffix(void)
  62 {
  63    return ".dll";
  64 }
  65
  66
  67 #elif defined(_EGL_PLATFORM_POSIX)
  68
  69
  70 static const char *DefaultDriverNames[] = {
  71    "egl_dri2",
  72    "egl_glx"
  73 };
  74
  75 typedef void * lib_handle;
  76
  77 static void *
  78 open_library(const char *filename)
  79 {
  80    return dlopen(filename, RTLD_LAZY);
  81 }
  82
  83 static void
  84 close_library(void *lib)
  85 {
  86    dlclose(lib);
  87 }
  88
  89
  90 static const char *
  91 library_suffix(void)
  92 {
  93    return ".so";
  94 }
  95
  96
  97 #endif
  98
  99
 100 #define NUM_PROBE_CACHE_SLOTS 8
 101 static struct {
 102    EGLint keys[NUM_PROBE_CACHE_SLOTS];
 103    const void *values[NUM_PROBE_CACHE_SLOTS];
 104 } _eglProbeCache;
 105
 106
 107 /**
 108  * Open the named driver and find its bootstrap function: _eglMain().
 109  */
 110 static _EGLMain_t
 111 _eglOpenLibrary(const char *driverPath, lib_handle *handle)
 112 {
 113    lib_handle lib;
 114    _EGLMain_t mainFunc = NULL;
 115    const char *error = "unknown error";
 116
 117    assert(driverPath);
 118
 119    _eglLog(_EGL_DEBUG, "dlopen(%s)", driverPath);
 120    lib = open_library(driverPath);
 121
 122 #if defined(_EGL_PLATFORM_WINDOWS)
 123    /* XXX untested */
 124    if (lib)
 125       mainFunc = (_EGLMain_t) GetProcAddress(lib, "_eglMain");
 126 #elif defined(_EGL_PLATFORM_POSIX)
 127    if (lib) {
 128       union {
 129          _EGLMain_t func;
 130          void *ptr;
 131       } tmp = { NULL };
 132       /* direct cast gives a warning when compiled with -pedantic */
 133       tmp.ptr = dlsym(lib, "_eglMain");
 134       mainFunc = tmp.func;
 135       if (!mainFunc)
 136          error = dlerror();
 137    }
 138    else {
 139       error = dlerror();
 140    }
 141 #endif
 142
 143    if (!lib) {
 144       _eglLog(_EGL_WARNING, "Could not open driver %s (%s)",
 145               driverPath, error);
 146       if (!getenv("EGL_DRIVER"))
 147          _eglLog(_EGL_WARNING,
 148                  "The driver can be overridden by setting EGL_DRIVER");
 149       return NULL;
 150    }
 151
 152    if (!mainFunc) {
 153       _eglLog(_EGL_WARNING, "_eglMain not found in %s (%s)",
 154               driverPath, error);
 155       if (lib)
 156          close_library(lib);
 157       return NULL;
 158    }
 159
 160    *handle = lib;
 161    return mainFunc;
 162 }
 163
 164
 165 /**
 166  * Load the named driver.
 167  */
 168 static _EGLDriver *
 169 _eglLoadDriver(const char *path, const char *args)
 170 {
 171    _EGLMain_t mainFunc;
 172    lib_handle lib;
 173    _EGLDriver *drv = NULL;
 174
 175    mainFunc = _eglOpenLibrary(path, &lib);
 176    if (!mainFunc)
 177       return NULL;
 178
 179    drv = mainFunc(args);
 180    if (!drv) {
 181       if (lib)
 182          close_library(lib);
 183       return NULL;
 184    }
 185
 186    if (!drv->Name) {
 187       _eglLog(_EGL_WARNING, "Driver loaded from %s has no name", path);
 188       drv->Name = "UNNAMED";
 189    }
 190
 191    drv->Path = _eglstrdup(path);
 192    drv->Args = (args) ? _eglstrdup(args) : NULL;
 193    if (!drv->Path || (args && !drv->Args)) {
 194       if (drv->Path)
 195          free((char *) drv->Path);
 196       if (drv->Args)
 197          free((char *) drv->Args);
 198       drv->Unload(drv);
 199       if (lib)
 200          close_library(lib);
 201       return NULL;
 202    }
 203
 204    drv->LibHandle = lib;
 205
 206    return drv;
 207 }
 208
 209
 210 /**
 211  * Match a display to a preloaded driver.
 212  *
 213  * The matching is done by finding the driver with the highest score.
 214  */
 215 _EGLDriver *
 216 _eglMatchDriver(_EGLDisplay *dpy)
 217 {
 218    _EGLDriver *best_drv = NULL;
 219    EGLint best_score = -1, i;
 220
 221    /*
 222     * this function is called after preloading and the drivers never change
 223     * after preloading.
 224     */
 225    for (i = 0; i < _eglGlobal.NumDrivers; i++) {
 226       _EGLDriver *drv = _eglGlobal.Drivers[i];
 227       EGLint score;
 228
 229       score = (drv->Probe) ? drv->Probe(drv, dpy) : 0;
 230       if (score > best_score) {
 231          if (best_drv) {
 232             _eglLog(_EGL_DEBUG, "driver %s has higher score than %s",
 233                   drv->Name, best_drv->Name);
 234          }
 235
 236          best_drv = drv;
 237          best_score = score;
 238          /* perfect match */
 239          if (score >= 100)
 240             break;
 241       }
 242    }
 243
 244    return best_drv;
 245 }
 246
 247
 248 /**
 249  * A loader function for use with _eglPreloadForEach.  The loader data is the
 250  * filename of the driver.   This function stops on the first valid driver.
 251  */
 252 static EGLBoolean
 253 _eglLoaderFile(const char *dir, size_t len, void *loader_data)
 254 {
 255    _EGLDriver *drv;
 256    char path[1024];
 257    const char *filename = (const char *) loader_data;
 258    size_t flen = strlen(filename);
 259
 260    /* make a full path */
 261    if (len + flen + 2 > sizeof(path))
 262       return EGL_TRUE;
 263    if (len) {
 264       memcpy(path, dir, len);
 265       path[len++] = '/';
 266    }
 267    memcpy(path + len, filename, flen);
 268    len += flen;
 269    path[len] = '\0';
 270
 271    if (library_suffix() == NULL || strstr(path, library_suffix()))
 272       drv = _eglLoadDriver(path, NULL);
 273    else {
 274       const char *suffix = library_suffix();
 275       size_t slen = strlen(suffix);
 276       const char *p;
 277       EGLBoolean need_suffix;
 278
 279       p = filename + flen - slen;
 280       need_suffix = (p < filename || strcmp(p, suffix) != 0);
 281       if (need_suffix && len + slen + 1 <= sizeof(path)) {
 282          strcpy(path + len, suffix);
 283          drv = _eglLoadDriver(path, NULL);
 284       } else {
 285          drv = NULL;
 286       }
 287    }
 288    if (!drv)
 289       return EGL_TRUE;
 290
 291    /* remember the driver and stop */
 292    _eglGlobal.Drivers[_eglGlobal.NumDrivers++] = drv;
 293    return EGL_FALSE;
 294 }
 295
 296
 297 /**
 298  * A loader function for use with _eglPreloadForEach.  The loader data is the
 299  * pattern (prefix) of the files to look for.
 300  */
 301 static EGLBoolean
 302 _eglLoaderPattern(const char *dir, size_t len, void *loader_data)
 303 {
 304 #if defined(_EGL_PLATFORM_POSIX)
 305    const char *prefix, *suffix;
 306    size_t prefix_len, suffix_len;
 307    DIR *dirp;
 308    struct dirent *dirent;
 309    char path[1024];
 310
 311    if (len + 2 > sizeof(path))
 312       return EGL_TRUE;
 313    if (len) {
 314       memcpy(path, dir, len);
 315       path[len++] = '/';
 316    }
 317    path[len] = '\0';
 318
 319    dirp = opendir(path);
 320    if (!dirp)
 321       return EGL_TRUE;
 322
 323    prefix = (const char *) loader_data;
 324    prefix_len = strlen(prefix);
 325    suffix = library_suffix();
 326    suffix_len = (suffix) ? strlen(suffix) : 0;
 327
 328    while ((dirent = readdir(dirp))) {
 329       _EGLDriver *drv;
 330       size_t dirent_len = strlen(dirent->d_name);
 331       const char *p;
 332
 333       /* match the prefix */
 334       if (strncmp(dirent->d_name, prefix, prefix_len) != 0)
 335          continue;
 336       /* match the suffix */
 337       if (suffix) {
 338          p = dirent->d_name + dirent_len - suffix_len;
 339          if (p < dirent->d_name || strcmp(p, suffix) != 0)
 340             continue;
 341       }
 342
 343       /* make a full path and load the driver */
 344       if (len + dirent_len + 1 <= sizeof(path)) {
 345          strcpy(path + len, dirent->d_name);
 346          drv = _eglLoadDriver(path, NULL);
 347          if (drv)
 348             _eglGlobal.Drivers[_eglGlobal.NumDrivers++] = drv;
 349       }
 350    }
 351
 352    closedir(dirp);
 353
 354    return EGL_TRUE;
 355 #else /* _EGL_PLATFORM_POSIX */
 356    /* stop immediately */
 357    return EGL_FALSE;
 358 #endif
 359 }
 360
 361
 362 /**
 363  * Run the preload function on each driver directory and return the number of
 364  * drivers loaded.
 365  *
 366  * The process may end prematurely if the callback function returns false.
 367  */
 368 static EGLint
 369 _eglPreloadForEach(const char *search_path,
 370                    EGLBoolean (*loader)(const char *, size_t, void *),
 371                    void *loader_data)
 372 {
 373    const char *cur, *next;
 374    size_t len;
 375    EGLint num_drivers = _eglGlobal.NumDrivers;
 376
 377    cur = search_path;
 378    while (cur) {
 379       next = strchr(cur, ':');
 380       len = (next) ? next - cur : strlen(cur);
 381
 382       if (!loader(cur, len, loader_data))
 383          break;
 384
 385       cur = (next) ? next + 1 : NULL;
 386    }
 387
 388    return (_eglGlobal.NumDrivers - num_drivers);
 389 }
 390
 391
 392 /**
 393  * Return a list of colon-separated driver directories.
 394  */
 395 static const char *
 396 _eglGetSearchPath(void)
 397 {
 398    static const char *search_path;
 399
 400 #if defined(_EGL_PLATFORM_POSIX) || defined(_EGL_PLATFORM_WINDOWS)
 401    if (!search_path) {
 402       static char buffer[1024];
 403       const char *p;
 404       int ret;
 405
 406       p = getenv("EGL_DRIVERS_PATH");
 407 #if defined(_EGL_PLATFORM_POSIX)
 408       if (p && (geteuid() != getuid() || getegid() != getgid())) {
 409          _eglLog(_EGL_DEBUG,
 410                "ignore EGL_DRIVERS_PATH for setuid/setgid binaries");
 411          p = NULL;
 412       }
 413 #endif /* _EGL_PLATFORM_POSIX */
 414
 415       if (p) {
 416          ret = _eglsnprintf(buffer, sizeof(buffer),
 417                "%s:%s", p, _EGL_DRIVER_SEARCH_DIR);
 418          if (ret > 0 && ret < sizeof(buffer))
 419             search_path = buffer;
 420       }
 421    }
 422    if (!search_path)
 423       search_path = _EGL_DRIVER_SEARCH_DIR;
 424 #else
 425    search_path = "";
 426 #endif
 427
 428    return search_path;
 429 }
 430
 431
 432 /**
 433  * Preload a user driver.
 434  *
 435  * A user driver can be specified by EGL_DRIVER.
 436  */
 437 static EGLBoolean
 438 _eglPreloadUserDriver(void)
 439 {
 440    const char *search_path = _eglGetSearchPath();
 441    char *env;
 442
 443    env = getenv("EGL_DRIVER");
 444 #if defined(_EGL_PLATFORM_POSIX)
 445    if (env && strchr(env, '/')) {
 446       search_path = "";
 447       if ((geteuid() != getuid() || getegid() != getgid())) {
 448          _eglLog(_EGL_DEBUG,
 449                "ignore EGL_DRIVER for setuid/setgid binaries");
 450          env = NULL;
 451       }
 452    }
 453 #endif /* _EGL_PLATFORM_POSIX */
 454    if (!env)
 455       return EGL_FALSE;
 456
 457    if (!_eglPreloadForEach(search_path, _eglLoaderFile, (void *) env)) {
 458       _eglLog(_EGL_WARNING, "EGL_DRIVER is set to an invalid driver");
 459       return EGL_FALSE;
 460    }
 461
 462    return EGL_TRUE;
 463 }
 464
 465
 466 /**
 467  * Preload display drivers.
 468  *
 469  * Display drivers are a set of drivers that support a certain display system.
 470  * The display system may be specified by EGL_DISPLAY.
 471  *
 472  * FIXME This makes libEGL a memory hog if an user driver is not specified and
 473  * there are many display drivers.
 474  */
 475 static EGLBoolean
 476 _eglPreloadDisplayDrivers(void)
 477 {
 478    const char *dpy;
 479    char prefix[32];
 480    int ret;
 481
 482    dpy = getenv("EGL_DISPLAY");
 483    if (!dpy || !dpy[0])
 484       dpy = _EGL_DEFAULT_DISPLAY;
 485    if (!dpy || !dpy[0])
 486       return EGL_FALSE;
 487
 488    ret = _eglsnprintf(prefix, sizeof(prefix), "egl_%s_", dpy);
 489    if (ret < 0 || ret >= sizeof(prefix))
 490       return EGL_FALSE;
 491
 492    return (_eglPreloadForEach(_eglGetSearchPath(),
 493             _eglLoaderPattern, (void *) prefix) > 0);
 494 }
 495
 496
 497 /**
 498  * Preload drivers.
 499  *
 500  * This function loads the driver modules and creates the corresponding
 501  * _EGLDriver objects.
 502  */
 503 EGLBoolean
 504 _eglPreloadDrivers(void)
 505 {
 506    EGLBoolean loaded;
 507
 508    /* protect the preloading process */
 509    _eglLockMutex(_eglGlobal.Mutex);
 510
 511    /* already preloaded */
 512    if (_eglGlobal.NumDrivers) {
 513       _eglUnlockMutex(_eglGlobal.Mutex);
 514       return EGL_TRUE;
 515    }
 516
 517    loaded = (_eglPreloadUserDriver() ||
 518              _eglPreloadDisplayDrivers());
 519
 520    _eglUnlockMutex(_eglGlobal.Mutex);
 521
 522    return loaded;
 523 }
 524
 525 /**
 526  * Unload preloaded drivers.
 527  */
 528 void
 529 _eglUnloadDrivers(void)
 530 {
 531    EGLint i;
 532
 533    /* this is called at atexit time */
 534    for (i = 0; i < _eglGlobal.NumDrivers; i++) {
 535       _EGLDriver *drv = _eglGlobal.Drivers[i];
 536       lib_handle handle = drv->LibHandle;
 537
 538       if (drv->Path)
 539          free((char *) drv->Path);
 540       if (drv->Args)
 541          free((char *) drv->Args);
 542
 543       /* destroy driver */
 544       if (drv->Unload)
 545          drv->Unload(drv);
 546
 547       if (handle)
 548          close_library(handle);
 549       _eglGlobal.Drivers[i] = NULL;
 550    }
 551
 552    _eglGlobal.NumDrivers = 0;
 553 }
 554
 555 _EGLDriver *
 556 _eglLoadDefaultDriver(EGLDisplay dpy, EGLint *major, EGLint *minor)
 557 {
 558    _EGLDriver *drv = NULL;
 559    int i;
 560
 561    _eglLockMutex(_eglGlobal.Mutex);
 562
 563    for (i = 0; i < ARRAY_SIZE(DefaultDriverNames); i++) {
 564       _eglPreloadForEach(_eglGetSearchPath(),
 565                          _eglLoaderFile, (void *) DefaultDriverNames[i]);
 566       if (_eglGlobal.NumDrivers == 0)
 567          continue;
 568       drv = _eglGlobal.Drivers[0];
 569       if (drv->API.Initialize(drv, dpy, major, minor))
 570          break;
 571       _eglUnloadDrivers();
 572    }
 573
 574    _eglUnlockMutex(_eglGlobal.Mutex);
 575
 576    return _eglGlobal.NumDrivers > 0 ? drv : NULL;
 577 }
 578
 579
 580 /**
 581  * Plug all the available fallback routines into the given driver's
 582  * dispatch table.
 583  */
 584 void
 585 _eglInitDriverFallbacks(_EGLDriver *drv)
 586 {
 587    /* If a pointer is set to NULL, then the device driver _really_ has
 588     * to implement it.
 589     */
 590    drv->API.Initialize = NULL;
 591    drv->API.Terminate = NULL;
 592
 593    drv->API.GetConfigs = _eglGetConfigs;
 594    drv->API.ChooseConfig = _eglChooseConfig;
 595    drv->API.GetConfigAttrib = _eglGetConfigAttrib;
 596
 597    drv->API.CreateContext = _eglCreateContext;
 598    drv->API.DestroyContext = _eglDestroyContext;
 599    drv->API.MakeCurrent = _eglMakeCurrent;
 600    drv->API.QueryContext = _eglQueryContext;
 601
 602    drv->API.CreateWindowSurface = _eglCreateWindowSurface;
 603    drv->API.CreatePixmapSurface = _eglCreatePixmapSurface;
 604    drv->API.CreatePbufferSurface = _eglCreatePbufferSurface;
 605    drv->API.DestroySurface = _eglDestroySurface;
 606    drv->API.QuerySurface = _eglQuerySurface;
 607    drv->API.SurfaceAttrib = _eglSurfaceAttrib;
 608    drv->API.BindTexImage = _eglBindTexImage;
 609    drv->API.ReleaseTexImage = _eglReleaseTexImage;
 610    drv->API.SwapInterval = _eglSwapInterval;
 611    drv->API.SwapBuffers = _eglSwapBuffers;
 612    drv->API.CopyBuffers = _eglCopyBuffers;
 613
 614    drv->API.QueryString = _eglQueryString;
 615    drv->API.WaitClient = _eglWaitClient;
 616    drv->API.WaitNative = _eglWaitNative;
 617
 618 #ifdef EGL_MESA_screen_surface
 619    drv->API.ChooseModeMESA = _eglChooseModeMESA;
 620    drv->API.GetModesMESA = _eglGetModesMESA;
 621    drv->API.GetModeAttribMESA = _eglGetModeAttribMESA;
 622    drv->API.GetScreensMESA = _eglGetScreensMESA;
 623    drv->API.CreateScreenSurfaceMESA = _eglCreateScreenSurfaceMESA;
 624    drv->API.ShowScreenSurfaceMESA = _eglShowScreenSurfaceMESA;
 625    drv->API.ScreenPositionMESA = _eglScreenPositionMESA;
 626    drv->API.QueryScreenMESA = _eglQueryScreenMESA;
 627    drv->API.QueryScreenSurfaceMESA = _eglQueryScreenSurfaceMESA;
 628    drv->API.QueryScreenModeMESA = _eglQueryScreenModeMESA;
 629    drv->API.QueryModeStringMESA = _eglQueryModeStringMESA;
 630 #endif /* EGL_MESA_screen_surface */
 631
 632 #ifdef EGL_VERSION_1_2
 633    drv->API.CreatePbufferFromClientBuffer = _eglCreatePbufferFromClientBuffer;
 634 #endif /* EGL_VERSION_1_2 */
 635
 636 #ifdef EGL_KHR_image_base
 637    drv->API.CreateImageKHR = _eglCreateImageKHR;
 638    drv->API.DestroyImageKHR = _eglDestroyImageKHR;
 639 #endif /* EGL_KHR_image_base */
 640 }
 641
 642
 643 /**
 644  * Invoke a callback function on each EGL search path.
 645  *
 646  * The first argument of the callback function is the name of the search path.
 647  * The second argument is the length of the name.
 648  */
 649 void
 650 _eglSearchPathForEach(EGLBoolean (*callback)(const char *, size_t, void *),
 651                       void *callback_data)
 652 {
 653    const char *search_path = _eglGetSearchPath();
 654    _eglPreloadForEach(search_path, callback, callback_data);
 655 }
 656
 657
 658 /**
 659  * Set the probe cache at the given key.
 660  *
 661  * A key, instead of a _EGLDriver, is used to allow the probe cache to be share
 662  * by multiple drivers.
 663  */
 664 void
 665 _eglSetProbeCache(EGLint key, const void *val)
 666 {
 667    EGLint idx;
 668
 669    for (idx = 0; idx < NUM_PROBE_CACHE_SLOTS; idx++) {
 670       if (!_eglProbeCache.keys[idx] || _eglProbeCache.keys[idx] == key)
 671          break;
 672    }
 673    assert(key > 0);
 674    assert(idx < NUM_PROBE_CACHE_SLOTS);
 675
 676    _eglProbeCache.keys[idx] = key;
 677    _eglProbeCache.values[idx] = val;
 678 }
 679
 680
 681 /**
 682  * Return the probe cache at the given key.
 683  */
 684 const void *
 685 _eglGetProbeCache(EGLint key)
 686 {
 687    EGLint idx;
 688
 689    for (idx = 0; idx < NUM_PROBE_CACHE_SLOTS; idx++) {
 690       if (!_eglProbeCache.keys[idx] || _eglProbeCache.keys[idx] == key)
 691          break;
 692    }
 693
 694    return (idx < NUM_PROBE_CACHE_SLOTS && _eglProbeCache.keys[idx] == key) ?
 695       _eglProbeCache.values[idx] : NULL;
 696 }