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