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 #include <errno.h>
 263
 264 /**
 265  * A loader function for use with _eglPreloadForEach.  The loader data is the
 266  * filename of the driver.   This function stops on the first valid driver.
 267  */
 268 static EGLBoolean
 269 _eglLoaderFile(const char *dir, size_t len, void *loader_data)
 270 {
 271    char path[1024];
 272    const char *filename = (const char *) loader_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    if (library_suffix()) {
 287       const char *suffix = library_suffix();
 288       size_t slen = strlen(suffix);
 289       const char *p;
 290       EGLBoolean need_suffix;
 291
 292       p = filename + flen - slen;
 293       need_suffix = (p < filename || strcmp(p, suffix) != 0);
 294       if (need_suffix) {
 295          /* overflow */
 296          if (len + slen + 1 > sizeof(path))
 297             return EGL_TRUE;
 298          strcpy(path + len, suffix);
 299       }
 300    }
 301
 302 #if defined(_EGL_OS_UNIX)
 303    /* check if the file exists */
 304    if (access(path, F_OK))
 305       return EGL_TRUE;
 306 #endif
 307
 308    _eglAddModule(path);
 309
 310    return EGL_TRUE;
 311 }
 312
 313
 314 /**
 315  * A loader function for use with _eglPreloadForEach.  The loader data is the
 316  * pattern (prefix) of the files to look for.
 317  */
 318 static EGLBoolean
 319 _eglLoaderPattern(const char *dir, size_t len, void *loader_data)
 320 {
 321 #if defined(_EGL_OS_UNIX)
 322    const char *prefix, *suffix;
 323    size_t prefix_len, suffix_len;
 324    DIR *dirp;
 325    struct dirent *dirent;
 326    char path[1024];
 327
 328    if (len + 2 > sizeof(path))
 329       return EGL_TRUE;
 330    if (len) {
 331       memcpy(path, dir, len);
 332       path[len++] = '/';
 333    }
 334    path[len] = '\0';
 335
 336    dirp = opendir(path);
 337    if (!dirp)
 338       return EGL_TRUE;
 339
 340    prefix = (const char *) loader_data;
 341    prefix_len = strlen(prefix);
 342    suffix = library_suffix();
 343    suffix_len = (suffix) ? strlen(suffix) : 0;
 344
 345    while ((dirent = readdir(dirp))) {
 346       size_t dirent_len = strlen(dirent->d_name);
 347       const char *p;
 348
 349       /* match the prefix */
 350       if (strncmp(dirent->d_name, prefix, prefix_len) != 0)
 351          continue;
 352       /* match the suffix */
 353       if (suffix) {
 354          p = dirent->d_name + dirent_len - suffix_len;
 355          if (p < dirent->d_name || strcmp(p, suffix) != 0)
 356             continue;
 357       }
 358
 359       /* make a full path and add it to the module array */
 360       if (len + dirent_len + 1 <= sizeof(path)) {
 361          strcpy(path + len, dirent->d_name);
 362          _eglAddModule(path);
 363       }
 364    }
 365
 366    closedir(dirp);
 367
 368    return EGL_TRUE;
 369 #else /* _EGL_OS_UNIX */
 370    /* stop immediately */
 371    return EGL_FALSE;
 372 #endif
 373 }
 374
 375
 376 /**
 377  * Run the callback function on each driver directory.
 378  *
 379  * The process may end prematurely if the callback function returns false.
 380  */
 381 static void
 382 _eglPreloadForEach(const char *search_path,
 383                    EGLBoolean (*loader)(const char *, size_t, void *),
 384                    void *loader_data)
 385 {
 386    const char *cur, *next;
 387    size_t len;
 388
 389    cur = search_path;
 390    while (cur) {
 391       next = strchr(cur, ':');
 392       len = (next) ? next - cur : strlen(cur);
 393
 394       if (!loader(cur, len, loader_data))
 395          break;
 396
 397       cur = (next) ? next + 1 : NULL;
 398    }
 399 }
 400
 401
 402 /**
 403  * Return a list of colon-separated driver directories.
 404  */
 405 static const char *
 406 _eglGetSearchPath(void)
 407 {
 408    static const char *search_path;
 409
 410 #if defined(_EGL_OS_UNIX) || defined(_EGL_OS_WINDOWS)
 411    if (!search_path) {
 412       static char buffer[1024];
 413       const char *p;
 414       int ret;
 415
 416       p = getenv("EGL_DRIVERS_PATH");
 417 #if defined(_EGL_OS_UNIX)
 418       if (p && (geteuid() != getuid() || getegid() != getgid())) {
 419          _eglLog(_EGL_DEBUG,
 420                "ignore EGL_DRIVERS_PATH for setuid/setgid binaries");
 421          p = NULL;
 422       }
 423 #endif /* _EGL_OS_UNIX */
 424
 425       if (p) {
 426          ret = _eglsnprintf(buffer, sizeof(buffer),
 427                "%s:%s", p, _EGL_DRIVER_SEARCH_DIR);
 428          if (ret > 0 && ret < sizeof(buffer))
 429             search_path = buffer;
 430       }
 431    }
 432    if (!search_path)
 433       search_path = _EGL_DRIVER_SEARCH_DIR;
 434 #else
 435    search_path = "";
 436 #endif
 437
 438    return search_path;
 439 }
 440
 441
 442 /**
 443  * Add the user driver to the module array.
 444  *
 445  * The user driver is specified by EGL_DRIVER.
 446  */
 447 static void
 448 _eglAddUserDriver(void)
 449 {
 450    const char *search_path = _eglGetSearchPath();
 451    char *env;
 452
 453    env = getenv("EGL_DRIVER");
 454 #if defined(_EGL_OS_UNIX)
 455    if (env && strchr(env, '/')) {
 456       search_path = "";
 457       if ((geteuid() != getuid() || getegid() != getgid())) {
 458          _eglLog(_EGL_DEBUG,
 459                "ignore EGL_DRIVER for setuid/setgid binaries");
 460          env = NULL;
 461       }
 462    }
 463 #endif /* _EGL_OS_UNIX */
 464    if (env)
 465       _eglPreloadForEach(search_path, _eglLoaderFile, (void *) env);
 466 }
 467
 468
 469 /**
 470  * Add default drivers to the module array.
 471  */
 472 static void
 473 _eglAddDefaultDrivers(void)
 474 {
 475    const char *search_path = _eglGetSearchPath();
 476    EGLint i;
 477 #if defined(_EGL_OS_WINDOWS)
 478    const char *DefaultDriverNames[] = {
 479       "egl_gallium"
 480    };
 481 #elif defined(_EGL_OS_UNIX)
 482    const char *DefaultDriverNames[] = {
 483       "egl_gallium",
 484       "egl_dri2",
 485       "egl_glx"
 486    };
 487 #endif
 488
 489    for (i = 0; i < ARRAY_SIZE(DefaultDriverNames); i++) {
 490       void *name = (void *) DefaultDriverNames[i];
 491       _eglPreloadForEach(search_path, _eglLoaderFile, name);
 492    }
 493 }
 494
 495
 496 /**
 497  * Add drivers to the module array.  Drivers will be loaded as they are matched
 498  * to displays.
 499  */
 500 static EGLBoolean
 501 _eglAddDrivers(void)
 502 {
 503    if (_eglModules)
 504       return EGL_TRUE;
 505
 506    /* the order here decides the priorities of the drivers */
 507    _eglAddUserDriver();
 508    _eglAddDefaultDrivers();
 509    _eglPreloadForEach(_eglGetSearchPath(), _eglLoaderPattern, (void *) "egl_");
 510
 511    return (_eglModules != NULL);
 512 }
 513
 514
 515 /**
 516  * Match a display to a driver.  The display is initialized unless use_probe is
 517  * true.
 518  *
 519  * The matching is done by finding the first driver that can initialize the
 520  * display, or when use_probe is true, the driver with highest score.
 521  */
 522 _EGLDriver *
 523 _eglMatchDriver(_EGLDisplay *dpy, EGLBoolean use_probe)
 524 {
 525    _EGLModule *mod;
 526    _EGLDriver *best_drv = NULL;
 527    EGLint best_score = 0;
 528    EGLint major, minor, i;
 529
 530    _eglLockMutex(&_eglModuleMutex);
 531
 532    if (!_eglAddDrivers()) {
 533       _eglUnlockMutex(&_eglModuleMutex);
 534       return EGL_FALSE;
 535    }
 536
 537    /* match the loaded modules */
 538    for (i = 0; i < _eglModules->Size; i++) {
 539       mod = (_EGLModule *) _eglModules->Elements[i];
 540       if (!mod->Driver)
 541          break;
 542
 543       if (use_probe) {
 544          EGLint score = (mod->Driver->Probe) ?
 545             mod->Driver->Probe(mod->Driver, dpy) : 1;
 546          if (score > best_score) {
 547             best_drv = mod->Driver;
 548             best_score = score;
 549          }
 550       }
 551       else {
 552          if (mod->Driver->API.Initialize(mod->Driver, dpy, &major, &minor)) {
 553             best_drv = mod->Driver;
 554             best_score = 100;
 555          }
 556       }
 557       /* perfect match */
 558       if (best_score >= 100)
 559          break;
 560    }
 561
 562    /* load more modules */
 563    if (!best_drv) {
 564       EGLint first_unloaded = i;
 565
 566       while (i < _eglModules->Size) {
 567          mod = (_EGLModule *) _eglModules->Elements[i];
 568          assert(!mod->Driver);
 569
 570          if (!_eglLoadModule(mod)) {
 571             /* remove invalid modules */
 572             _eglEraseArray(_eglModules, i, _eglFreeModule);
 573             continue;
 574          }
 575
 576          if (use_probe) {
 577             best_score = (mod->Driver->Probe) ?
 578                mod->Driver->Probe(mod->Driver, dpy) : 1;
 579          }
 580          else {
 581             if (mod->Driver->API.Initialize(mod->Driver, dpy, &major, &minor))
 582                best_score = 100;
 583          }
 584
 585          if (best_score > 0) {
 586             best_drv = mod->Driver;
 587             /* loaded modules come before unloaded ones */
 588             if (first_unloaded != i) {
 589                void *tmp = _eglModules->Elements[i];
 590                _eglModules->Elements[i] =
 591                   _eglModules->Elements[first_unloaded];
 592                _eglModules->Elements[first_unloaded] = tmp;
 593             }
 594             break;
 595          }
 596          else {
 597             _eglUnloadModule(mod);
 598             i++;
 599          }
 600       }
 601    }
 602
 603    _eglUnlockMutex(&_eglModuleMutex);
 604
 605    if (best_drv) {
 606       _eglLog(_EGL_DEBUG, "the best driver is %s (score %d)",
 607             best_drv->Name, best_score);
 608       if (!use_probe) {
 609          dpy->Driver = best_drv;
 610          dpy->Initialized = EGL_TRUE;
 611          dpy->APImajor = major;
 612          dpy->APIminor = minor;
 613       }
 614    }
 615
 616    return best_drv;
 617 }
 618
 619
 620 __eglMustCastToProperFunctionPointerType
 621 _eglGetDriverProc(const char *procname)
 622 {
 623    EGLint i;
 624    _EGLProc proc = NULL;
 625
 626    if (!_eglModules) {
 627       /* load the driver for the default display */
 628       EGLDisplay egldpy = eglGetDisplay(EGL_DEFAULT_DISPLAY);
 629       _EGLDisplay *dpy = _eglLookupDisplay(egldpy);
 630       if (!dpy || !_eglMatchDriver(dpy, EGL_TRUE))
 631          return NULL;
 632    }
 633
 634    for (i = 0; i < _eglModules->Size; i++) {
 635       _EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
 636
 637       if (!mod->Driver)
 638          break;
 639       proc = mod->Driver->API.GetProcAddress(mod->Driver, procname);
 640       if (proc)
 641          break;
 642    }
 643
 644    return proc;
 645 }
 646
 647
 648 /**
 649  * Unload all drivers.
 650  */
 651 void
 652 _eglUnloadDrivers(void)
 653 {
 654    /* this is called at atexit time */
 655    if (_eglModules) {
 656 #if defined(_EGL_OS_UNIX)
 657       _eglDestroyArray(_eglModules, _eglFreeModule);
 658 #elif defined(_EGL_OS_WINDOWS)
 659       /* XXX Windows unloads DLLs before atexit */
 660       _eglDestroyArray(_eglModules, NULL);
 661 #endif
 662       _eglModules = NULL;
 663    }
 664 }
 665
 666
 667 /**
 668  * Plug all the available fallback routines into the given driver's
 669  * dispatch table.
 670  */
 671 void
 672 _eglInitDriverFallbacks(_EGLDriver *drv)
 673 {
 674    /* If a pointer is set to NULL, then the device driver _really_ has
 675     * to implement it.
 676     */
 677    drv->API.Initialize = NULL;
 678    drv->API.Terminate = NULL;
 679
 680    drv->API.GetConfigs = _eglGetConfigs;
 681    drv->API.ChooseConfig = _eglChooseConfig;
 682    drv->API.GetConfigAttrib = _eglGetConfigAttrib;
 683
 684    drv->API.CreateContext = _eglCreateContext;
 685    drv->API.DestroyContext = _eglDestroyContext;
 686    drv->API.MakeCurrent = _eglMakeCurrent;
 687    drv->API.QueryContext = _eglQueryContext;
 688
 689    drv->API.CreateWindowSurface = _eglCreateWindowSurface;
 690    drv->API.CreatePixmapSurface = _eglCreatePixmapSurface;
 691    drv->API.CreatePbufferSurface = _eglCreatePbufferSurface;
 692    drv->API.DestroySurface = _eglDestroySurface;
 693    drv->API.QuerySurface = _eglQuerySurface;
 694    drv->API.SurfaceAttrib = _eglSurfaceAttrib;
 695    drv->API.BindTexImage = _eglBindTexImage;
 696    drv->API.ReleaseTexImage = _eglReleaseTexImage;
 697    drv->API.SwapInterval = _eglSwapInterval;
 698    drv->API.SwapBuffers = _eglSwapBuffers;
 699    drv->API.CopyBuffers = _eglCopyBuffers;
 700
 701    drv->API.QueryString = _eglQueryString;
 702    drv->API.WaitClient = _eglWaitClient;
 703    drv->API.WaitNative = _eglWaitNative;
 704
 705 #ifdef EGL_MESA_screen_surface
 706    drv->API.ChooseModeMESA = _eglChooseModeMESA;
 707    drv->API.GetModesMESA = _eglGetModesMESA;
 708    drv->API.GetModeAttribMESA = _eglGetModeAttribMESA;
 709    drv->API.GetScreensMESA = _eglGetScreensMESA;
 710    drv->API.CreateScreenSurfaceMESA = _eglCreateScreenSurfaceMESA;
 711    drv->API.ShowScreenSurfaceMESA = _eglShowScreenSurfaceMESA;
 712    drv->API.ScreenPositionMESA = _eglScreenPositionMESA;
 713    drv->API.QueryScreenMESA = _eglQueryScreenMESA;
 714    drv->API.QueryScreenSurfaceMESA = _eglQueryScreenSurfaceMESA;
 715    drv->API.QueryScreenModeMESA = _eglQueryScreenModeMESA;
 716    drv->API.QueryModeStringMESA = _eglQueryModeStringMESA;
 717 #endif /* EGL_MESA_screen_surface */
 718
 719 #ifdef EGL_VERSION_1_2
 720    drv->API.CreatePbufferFromClientBuffer = _eglCreatePbufferFromClientBuffer;
 721 #endif /* EGL_VERSION_1_2 */
 722
 723 #ifdef EGL_KHR_image_base
 724    drv->API.CreateImageKHR = _eglCreateImageKHR;
 725    drv->API.DestroyImageKHR = _eglDestroyImageKHR;
 726 #endif /* EGL_KHR_image_base */
 727 }
 728
 729
 730 /**
 731  * Invoke a callback function on each EGL search path.
 732  *
 733  * The first argument of the callback function is the name of the search path.
 734  * The second argument is the length of the name.
 735  */
 736 void
 737 _eglSearchPathForEach(EGLBoolean (*callback)(const char *, size_t, void *),
 738                       void *callback_data)
 739 {
 740    const char *search_path = _eglGetSearchPath();
 741    _eglPreloadForEach(search_path, callback, callback_data);
 742 }