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 #include "eglmutex.h"
  26
  27 #if defined(_EGL_OS_UNIX)
  28 #include <dlfcn.h>
  29 #include <sys/types.h>
  30 #include <dirent.h>
  31 #include <unistd.h>
  32 #endif
  33
  34
  35 typedef struct _egl_module {
  36    char *Path;
  37    void *Handle;
  38    _EGLDriver *Driver;
  39 } _EGLModule;
  40
  41 static _EGL_DECLARE_MUTEX(_eglModuleMutex);
  42 static _EGLArray *_eglModules;
  43
  44
  45 /**
  46  * Wrappers for dlopen/dlclose()
  47  */
  48 #if defined(_EGL_OS_WINDOWS)
  49
  50
  51 typedef HMODULE lib_handle;
  52
  53 static HMODULE
  54 open_library(const char *filename)
  55 {
  56    return LoadLibrary(filename);
  57 }
  58
  59 static void
  60 close_library(HMODULE lib)
  61 {
  62    FreeLibrary(lib);
  63 }
  64
  65
  66 static const char *
  67 library_suffix(void)
  68 {
  69    return ".dll";
  70 }
  71
  72
  73 #elif defined(_EGL_OS_UNIX)
  74
  75
  76 typedef void * lib_handle;
  77
  78 static void *
  79 open_library(const char *filename)
  80 {
  81    return dlopen(filename, RTLD_LAZY);
  82 }
  83
  84 static void
  85 close_library(void *lib)
  86 {
  87    dlclose(lib);
  88 }
  89
  90
  91 static const char *
  92 library_suffix(void)
  93 {
  94    return ".so";
  95 }
  96
  97
  98 #endif
  99
 100
 101 /**
 102  * Open the named driver and find its bootstrap function: _eglMain().
 103  */
 104 static _EGLMain_t
 105 _eglOpenLibrary(const char *driverPath, lib_handle *handle)
 106 {
 107    lib_handle lib;
 108    _EGLMain_t mainFunc = NULL;
 109    const char *error = "unknown error";
 110
 111    assert(driverPath);
 112
 113    _eglLog(_EGL_DEBUG, "dlopen(%s)", driverPath);
 114    lib = open_library(driverPath);
 115
 116 #if defined(_EGL_OS_WINDOWS)
 117    /* XXX untested */
 118    if (lib)
 119       mainFunc = (_EGLMain_t) GetProcAddress(lib, "_eglMain");
 120 #elif defined(_EGL_OS_UNIX)
 121    if (lib) {
 122       union {
 123          _EGLMain_t func;
 124          void *ptr;
 125       } tmp = { NULL };
 126       /* direct cast gives a warning when compiled with -pedantic */
 127       tmp.ptr = dlsym(lib, "_eglMain");
 128       mainFunc = tmp.func;
 129       if (!mainFunc)
 130          error = dlerror();
 131    }
 132    else {
 133       error = dlerror();
 134    }
 135 #endif
 136
 137    if (!lib) {
 138       _eglLog(_EGL_WARNING, "Could not open driver %s (%s)",
 139               driverPath, error);
 140       if (!getenv("EGL_DRIVER"))
 141          _eglLog(_EGL_WARNING,
 142                  "The driver can be overridden by setting EGL_DRIVER");
 143       return NULL;
 144    }
 145
 146    if (!mainFunc) {
 147       _eglLog(_EGL_WARNING, "_eglMain not found in %s (%s)",
 148               driverPath, error);
 149       if (lib)
 150          close_library(lib);
 151       return NULL;
 152    }
 153
 154    *handle = lib;
 155    return mainFunc;
 156 }
 157
 158
 159 /**
 160  * Load a module and create the driver object.
 161  */
 162 static EGLBoolean
 163 _eglLoadModule(_EGLModule *mod)
 164 {
 165    _EGLMain_t mainFunc;
 166    lib_handle lib;
 167    _EGLDriver *drv;
 168
 169    mainFunc = _eglOpenLibrary(mod->Path, &lib);
 170    if (!mainFunc)
 171       return EGL_FALSE;
 172
 173    drv = mainFunc(NULL);
 174    if (!drv) {
 175       if (lib)
 176          close_library(lib);
 177       return EGL_FALSE;
 178    }
 179
 180    if (!drv->Name) {
 181       _eglLog(_EGL_WARNING, "Driver loaded from %s has no name", mod->Path);
 182       drv->Name = "UNNAMED";
 183    }
 184
 185    mod->Handle = (void *) lib;
 186    mod->Driver = drv;
 187
 188    return EGL_TRUE;
 189 }
 190
 191
 192 /**
 193  * Unload a module.
 194  */
 195 static void
 196 _eglUnloadModule(_EGLModule *mod)
 197 {
 198    /* destroy the driver */
 199    if (mod->Driver && mod->Driver->Unload)
 200       mod->Driver->Unload(mod->Driver);
 201    if (mod->Handle)
 202       close_library(mod->Handle);
 203
 204    mod->Driver = NULL;
 205    mod->Handle = NULL;
 206 }
 207
 208
 209 /**
 210  * Add a module to the module array.
 211  */
 212 static _EGLModule *
 213 _eglAddModule(const char *path)
 214 {
 215    _EGLModule *mod;
 216    EGLint i;
 217
 218    if (!_eglModules) {
 219       _eglModules = _eglCreateArray("Module", 8);
 220       if (!_eglModules)
 221          return NULL;
 222    }
 223
 224    /* find duplicates */
 225    for (i = 0; i < _eglModules->Size; i++) {
 226       mod = _eglModules->Elements[i];
 227       if (strcmp(mod->Path, path) == 0)
 228          return mod;
 229    }
 230
 231    /* allocate a new one */
 232    mod = calloc(1, sizeof(*mod));
 233    if (mod) {
 234       mod->Path = _eglstrdup(path);
 235       if (!mod->Path) {
 236          free(mod);
 237          mod = NULL;
 238       }
 239    }
 240    if (mod) {
 241       _eglAppendArray(_eglModules, (void *) mod);
 242       _eglLog(_EGL_DEBUG, "added %s to module array", mod->Path);
 243    }
 244
 245    return mod;
 246 }
 247
 248
 249 /**
 250  * Free a module.
 251  */
 252 static void
 253 _eglFreeModule(void *module)
 254 {
 255    _EGLModule *mod = (_EGLModule *) module;
 256
 257    _eglUnloadModule(mod);
 258    free(mod->Path);
 259    free(mod);
 260 }
 261
 262
 263 /**
 264  * A loader function for use with _eglPreloadForEach.  The loader data is the
 265  * filename of the driver.   This function stops on the first valid driver.
 266  */
 267 static EGLBoolean
 268 _eglLoaderFile(const char *dir, size_t len, void *loader_data)
 269 {
 270    char path[1024];
 271    const char *filename = (const char *) loader_data;
 272    size_t flen = strlen(filename);
 273
 274    /* make a full path */
 275    if (len + flen + 2 > sizeof(path))
 276       return EGL_TRUE;
 277    if (len) {
 278       memcpy(path, dir, len);
 279       path[len++] = '/';
 280    }
 281    memcpy(path + len, filename, flen);
 282    len += flen;
 283    path[len] = '\0';
 284
 285    if (library_suffix()) {
 286       const char *suffix = library_suffix();
 287       size_t slen = strlen(suffix);
 288       const char *p;
 289       EGLBoolean need_suffix;
 290
 291       p = filename + flen - slen;
 292       need_suffix = (p < filename || strcmp(p, suffix) != 0);
 293       if (need_suffix) {
 294          /* overflow */
 295          if (len + slen + 1 > sizeof(path))
 296             return EGL_TRUE;
 297          strcpy(path + len, suffix);
 298       }
 299    }
 300
 301 #if defined(_EGL_OS_UNIX)
 302    /* check if the file exists */
 303    if (access(path, F_OK))
 304       return EGL_TRUE;
 305 #endif
 306
 307    _eglAddModule(path);
 308
 309    return EGL_TRUE;
 310 }
 311
 312
 313 /**
 314  * A loader function for use with _eglPreloadForEach.  The loader data is the
 315  * pattern (prefix) of the files to look for.
 316  */
 317 static EGLBoolean
 318 _eglLoaderPattern(const char *dir, size_t len, void *loader_data)
 319 {
 320 #if defined(_EGL_OS_UNIX)
 321    const char *prefix, *suffix;
 322    size_t prefix_len, suffix_len;
 323    DIR *dirp;
 324    struct dirent *dirent;
 325    char path[1024];
 326
 327    if (len + 2 > sizeof(path))
 328       return EGL_TRUE;
 329    if (len) {
 330       memcpy(path, dir, len);
 331       path[len++] = '/';
 332    }
 333    path[len] = '\0';
 334
 335    dirp = opendir(path);
 336    if (!dirp)
 337       return EGL_TRUE;
 338
 339    prefix = (const char *) loader_data;
 340    prefix_len = strlen(prefix);
 341    suffix = library_suffix();
 342    suffix_len = (suffix) ? strlen(suffix) : 0;
 343
 344    while ((dirent = readdir(dirp))) {
 345       size_t dirent_len = strlen(dirent->d_name);
 346       const char *p;
 347
 348       /* match the prefix */
 349       if (strncmp(dirent->d_name, prefix, prefix_len) != 0)
 350          continue;
 351       /* match the suffix */
 352       if (suffix) {
 353          p = dirent->d_name + dirent_len - suffix_len;
 354          if (p < dirent->d_name || strcmp(p, suffix) != 0)
 355             continue;
 356       }
 357
 358       /* make a full path and add it to the module array */
 359       if (len + dirent_len + 1 <= sizeof(path)) {
 360          strcpy(path + len, dirent->d_name);
 361          _eglAddModule(path);
 362       }
 363    }
 364
 365    closedir(dirp);
 366
 367    return EGL_TRUE;
 368 #else /* _EGL_OS_UNIX */
 369    /* stop immediately */
 370    return EGL_FALSE;
 371 #endif
 372 }
 373
 374
 375 /**
 376  * Run the callback function on each driver directory.
 377  *
 378  * The process may end prematurely if the callback function returns false.
 379  */
 380 static void
 381 _eglPreloadForEach(const char *search_path,
 382                    EGLBoolean (*loader)(const char *, size_t, void *),
 383                    void *loader_data)
 384 {
 385    const char *cur, *next;
 386    size_t len;
 387
 388    cur = search_path;
 389    while (cur) {
 390       next = strchr(cur, ':');
 391       len = (next) ? next - cur : strlen(cur);
 392
 393       if (!loader(cur, len, loader_data))
 394          break;
 395
 396       cur = (next) ? next + 1 : NULL;
 397    }
 398 }
 399
 400
 401 /**
 402  * Return a list of colon-separated driver directories.
 403  */
 404 static const char *
 405 _eglGetSearchPath(void)
 406 {
 407    static const char *search_path;
 408
 409 #if defined(_EGL_OS_UNIX) || defined(_EGL_OS_WINDOWS)
 410    if (!search_path) {
 411       static char buffer[1024];
 412       const char *p;
 413       int ret;
 414
 415       p = getenv("EGL_DRIVERS_PATH");
 416 #if defined(_EGL_OS_UNIX)
 417       if (p && (geteuid() != getuid() || getegid() != getgid())) {
 418          _eglLog(_EGL_DEBUG,
 419                "ignore EGL_DRIVERS_PATH for setuid/setgid binaries");
 420          p = NULL;
 421       }
 422 #endif /* _EGL_OS_UNIX */
 423
 424       if (p) {
 425          ret = _eglsnprintf(buffer, sizeof(buffer),
 426                "%s:%s", p, _EGL_DRIVER_SEARCH_DIR);
 427          if (ret > 0 && ret < sizeof(buffer))
 428             search_path = buffer;
 429       }
 430    }
 431    if (!search_path)
 432       search_path = _EGL_DRIVER_SEARCH_DIR;
 433 #else
 434    search_path = "";
 435 #endif
 436
 437    return search_path;
 438 }
 439
 440
 441 /**
 442  * Add the user driver to the module array.
 443  *
 444  * The user driver is specified by EGL_DRIVER.
 445  */
 446 static void
 447 _eglAddUserDriver(void)
 448 {
 449    const char *search_path = _eglGetSearchPath();
 450    char *env;
 451
 452    env = getenv("EGL_DRIVER");
 453 #if defined(_EGL_OS_UNIX)
 454    if (env && strchr(env, '/')) {
 455       search_path = "";
 456       if ((geteuid() != getuid() || getegid() != getgid())) {
 457          _eglLog(_EGL_DEBUG,
 458                "ignore EGL_DRIVER for setuid/setgid binaries");
 459          env = NULL;
 460       }
 461    }
 462 #endif /* _EGL_OS_UNIX */
 463    if (env)
 464       _eglPreloadForEach(search_path, _eglLoaderFile, (void *) env);
 465 }
 466
 467
 468 /**
 469  * Add default drivers to the module array.
 470  */
 471 static void
 472 _eglAddDefaultDrivers(void)
 473 {
 474    const char *search_path = _eglGetSearchPath();
 475    EGLint i;
 476 #if defined(_EGL_OS_WINDOWS)
 477    const char *DefaultDriverNames[] = {
 478       "egl_gallium"
 479    };
 480 #elif defined(_EGL_OS_UNIX)
 481    const char *DefaultDriverNames[] = {
 482       "egl_gallium",
 483       "egl_dri2",
 484       "egl_glx"
 485    };
 486 #endif
 487
 488    for (i = 0; i < ARRAY_SIZE(DefaultDriverNames); i++) {
 489       void *name = (void *) DefaultDriverNames[i];
 490       _eglPreloadForEach(search_path, _eglLoaderFile, name);
 491    }
 492 }
 493
 494
 495 /**
 496  * Add drivers to the module array.  Drivers will be loaded as they are matched
 497  * to displays.
 498  */
 499 static EGLBoolean
 500 _eglAddDrivers(void)
 501 {
 502    if (_eglModules)
 503       return EGL_TRUE;
 504
 505    /* the order here decides the priorities of the drivers */
 506    _eglAddUserDriver();
 507    _eglAddDefaultDrivers();
 508    _eglPreloadForEach(_eglGetSearchPath(), _eglLoaderPattern, (void *) "egl_");
 509
 510    return (_eglModules != NULL);
 511 }
 512
 513
 514 /**
 515  * Match a display to a driver.  The display is initialized unless use_probe is
 516  * true.
 517  *
 518  * The matching is done by finding the first driver that can initialize the
 519  * display, or when use_probe is true, the driver with highest score.
 520  */
 521 _EGLDriver *
 522 _eglMatchDriver(_EGLDisplay *dpy, EGLBoolean use_probe)
 523 {
 524    _EGLModule *mod;
 525    _EGLDriver *best_drv = NULL;
 526    EGLint best_score = 0;
 527    EGLint major, minor, i;
 528
 529    _eglLockMutex(&_eglModuleMutex);
 530
 531    if (!_eglAddDrivers()) {
 532       _eglUnlockMutex(&_eglModuleMutex);
 533       return EGL_FALSE;
 534    }
 535
 536    /* match the loaded modules */
 537    for (i = 0; i < _eglModules->Size; i++) {
 538       mod = (_EGLModule *) _eglModules->Elements[i];
 539       if (!mod->Driver)
 540          break;
 541
 542       if (use_probe) {
 543          EGLint score = (mod->Driver->Probe) ?
 544             mod->Driver->Probe(mod->Driver, dpy) : 1;
 545          if (score > best_score) {
 546             best_drv = mod->Driver;
 547             best_score = score;
 548          }
 549       }
 550       else {
 551          if (mod->Driver->API.Initialize(mod->Driver, dpy, &major, &minor)) {
 552             best_drv = mod->Driver;
 553             best_score = 100;
 554          }
 555       }
 556       /* perfect match */
 557       if (best_score >= 100)
 558          break;
 559    }
 560
 561    /* load more modules */
 562    if (!best_drv) {
 563       EGLint first_unloaded = i;
 564
 565       while (i < _eglModules->Size) {
 566          mod = (_EGLModule *) _eglModules->Elements[i];
 567          assert(!mod->Driver);
 568
 569          if (!_eglLoadModule(mod)) {
 570             /* remove invalid modules */
 571             _eglEraseArray(_eglModules, i, _eglFreeModule);
 572             continue;
 573          }
 574
 575          if (use_probe) {
 576             best_score = (mod->Driver->Probe) ?
 577                mod->Driver->Probe(mod->Driver, dpy) : 1;
 578          }
 579          else {
 580             if (mod->Driver->API.Initialize(mod->Driver, dpy, &major, &minor))
 581                best_score = 100;
 582          }
 583
 584          if (best_score > 0) {
 585             best_drv = mod->Driver;
 586             /* loaded modules come before unloaded ones */
 587             if (first_unloaded != i) {
 588                void *tmp = _eglModules->Elements[i];
 589                _eglModules->Elements[i] =
 590                   _eglModules->Elements[first_unloaded];
 591                _eglModules->Elements[first_unloaded] = tmp;
 592             }
 593             break;
 594          }
 595          else {
 596             _eglUnloadModule(mod);
 597             i++;
 598          }
 599       }
 600    }
 601
 602    _eglUnlockMutex(&_eglModuleMutex);
 603
 604    if (best_drv) {
 605       _eglLog(_EGL_DEBUG, "the best driver is %s (score %d)",
 606             best_drv->Name, best_score);
 607       if (!use_probe) {
 608          dpy->Driver = best_drv;
 609          dpy->Initialized = EGL_TRUE;
 610          dpy->APImajor = major;
 611          dpy->APIminor = minor;
 612       }
 613    }
 614
 615    return best_drv;
 616 }
 617
 618
 619 __eglMustCastToProperFunctionPointerType
 620 _eglGetDriverProc(const char *procname)
 621 {
 622    EGLint i;
 623    _EGLProc proc = NULL;
 624
 625    if (!_eglModules) {
 626       /* load the driver for the default display */
 627       EGLDisplay egldpy = eglGetDisplay(EGL_DEFAULT_DISPLAY);
 628       _EGLDisplay *dpy = _eglLookupDisplay(egldpy);
 629       if (!dpy || !_eglMatchDriver(dpy, EGL_TRUE))
 630          return NULL;
 631    }
 632
 633    for (i = 0; i < _eglModules->Size; i++) {
 634       _EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
 635
 636       if (!mod->Driver)
 637          break;
 638       proc = mod->Driver->API.GetProcAddress(mod->Driver, procname);
 639       if (proc)
 640          break;
 641    }
 642
 643    return proc;
 644 }
 645
 646
 647 /**
 648  * Unload all drivers.
 649  */
 650 void
 651 _eglUnloadDrivers(void)
 652 {
 653    /* this is called at atexit time */
 654    if (_eglModules) {
 655 #if defined(_EGL_OS_UNIX)
 656       _eglDestroyArray(_eglModules, _eglFreeModule);
 657 #elif defined(_EGL_OS_WINDOWS)
 658       /* XXX Windows unloads DLLs before atexit */
 659       _eglDestroyArray(_eglModules, NULL);
 660 #endif
 661       _eglModules = NULL;
 662    }
 663 }
 664
 665
 666 /**
 667  * Plug all the available fallback routines into the given driver's
 668  * dispatch table.
 669  */
 670 void
 671 _eglInitDriverFallbacks(_EGLDriver *drv)
 672 {
 673    /* If a pointer is set to NULL, then the device driver _really_ has
 674     * to implement it.
 675     */
 676    drv->API.Initialize = NULL;
 677    drv->API.Terminate = NULL;
 678
 679    drv->API.GetConfigs = _eglGetConfigs;
 680    drv->API.ChooseConfig = _eglChooseConfig;
 681    drv->API.GetConfigAttrib = _eglGetConfigAttrib;
 682
 683    drv->API.CreateContext = _eglCreateContext;
 684    drv->API.DestroyContext = _eglDestroyContext;
 685    drv->API.MakeCurrent = _eglMakeCurrent;
 686    drv->API.QueryContext = _eglQueryContext;
 687
 688    drv->API.CreateWindowSurface = _eglCreateWindowSurface;
 689    drv->API.CreatePixmapSurface = _eglCreatePixmapSurface;
 690    drv->API.CreatePbufferSurface = _eglCreatePbufferSurface;
 691    drv->API.DestroySurface = _eglDestroySurface;
 692    drv->API.QuerySurface = _eglQuerySurface;
 693    drv->API.SurfaceAttrib = _eglSurfaceAttrib;
 694    drv->API.BindTexImage = _eglBindTexImage;
 695    drv->API.ReleaseTexImage = _eglReleaseTexImage;
 696    drv->API.SwapInterval = _eglSwapInterval;
 697    drv->API.SwapBuffers = _eglSwapBuffers;
 698    drv->API.CopyBuffers = _eglCopyBuffers;
 699
 700    drv->API.QueryString = _eglQueryString;
 701    drv->API.WaitClient = _eglWaitClient;
 702    drv->API.WaitNative = _eglWaitNative;
 703
 704 #ifdef EGL_MESA_screen_surface
 705    drv->API.ChooseModeMESA = _eglChooseModeMESA;
 706    drv->API.GetModesMESA = _eglGetModesMESA;
 707    drv->API.GetModeAttribMESA = _eglGetModeAttribMESA;
 708    drv->API.GetScreensMESA = _eglGetScreensMESA;
 709    drv->API.CreateScreenSurfaceMESA = _eglCreateScreenSurfaceMESA;
 710    drv->API.ShowScreenSurfaceMESA = _eglShowScreenSurfaceMESA;
 711    drv->API.ScreenPositionMESA = _eglScreenPositionMESA;
 712    drv->API.QueryScreenMESA = _eglQueryScreenMESA;
 713    drv->API.QueryScreenSurfaceMESA = _eglQueryScreenSurfaceMESA;
 714    drv->API.QueryScreenModeMESA = _eglQueryScreenModeMESA;
 715    drv->API.QueryModeStringMESA = _eglQueryModeStringMESA;
 716 #endif /* EGL_MESA_screen_surface */
 717
 718 #ifdef EGL_VERSION_1_2
 719    drv->API.CreatePbufferFromClientBuffer = _eglCreatePbufferFromClientBuffer;
 720 #endif /* EGL_VERSION_1_2 */
 721
 722 #ifdef EGL_KHR_image_base
 723    drv->API.CreateImageKHR = _eglCreateImageKHR;
 724    drv->API.DestroyImageKHR = _eglDestroyImageKHR;
 725 #endif /* EGL_KHR_image_base */
 726 }
 727
 728
 729 /**
 730  * Invoke a callback function on each EGL search path.
 731  *
 732  * The first argument of the callback function is the name of the search path.
 733  * The second argument is the length of the name.
 734  */
 735 void
 736 _eglSearchPathForEach(EGLBoolean (*callback)(const char *, size_t, void *),
 737                       void *callback_data)
 738 {
 739    const char *search_path = _eglGetSearchPath();
 740    _eglPreloadForEach(search_path, callback, callback_data);
 741 }