src/drm-shim/device.c

   1 /*
   2  * Copyright © 2018 Broadcom
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /** @file
  25  *
  26  * Implements core GEM support (particularly ioctls) underneath the libc ioctl
  27  * wrappers, and calls into the driver-specific code as necessary.
  28  */
  29
  30 #include <c11/threads.h>
  31 #include <errno.h>
  32 #include <linux/memfd.h>
  33 #include <stdbool.h>
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <sys/ioctl.h>
  38 #include <sys/mman.h>
  39 #include <unistd.h>
  40 #include "drm-uapi/drm.h"
  41 #include "drm_shim.h"
  42 #include "util/hash_table.h"
  43 #include "util/u_atomic.h"
  44
  45 static mtx_t handle_lock = _MTX_INITIALIZER_NP;
  46
  47 #ifndef HAVE_MEMFD_CREATE
  48 #include <sys/syscall.h>
  49
  50 static inline int
  51 memfd_create(const char *name, unsigned int flags)
  52 {
  53    return syscall(SYS_memfd_create, name, flags);
  54 }
  55 #endif
  56
  57 /* Global state for the shim shared between libc, core, and driver. */
  58 struct shim_device shim_device;
  59
  60 static uint32_t
  61 uint_key_hash(const void *key)
  62 {
  63    return (uintptr_t)key;
  64 }
  65
  66 static bool
  67 uint_key_compare(const void *a, const void *b)
  68 {
  69    return a == b;
  70 }
  71
  72 /**
  73  * Called when the first libc shim is called, to initialize GEM simulation
  74  * state (other than the shims themselves).
  75  */
  76 void
  77 drm_shim_device_init(void)
  78 {
  79    shim_device.fd_map = _mesa_hash_table_create(NULL,
  80                                                 uint_key_hash,
  81                                                 uint_key_compare);
  82
  83    drm_shim_driver_init();
  84 }
  85
  86 static struct shim_fd *
  87 drm_shim_file_create(int fd)
  88 {
  89    struct shim_fd *shim_fd = calloc(1, sizeof(*shim_fd));
  90
  91    shim_fd->fd = fd;
  92    shim_fd->handles = _mesa_hash_table_create(NULL,
  93                                               uint_key_hash,
  94                                               uint_key_compare);
  95
  96    return shim_fd;
  97 }
  98
  99 /**
 100  * Called when the libc shims have interposed an open or dup of our simulated
 101  * DRM device.
 102  */
 103 void drm_shim_fd_register(int fd, struct shim_fd *shim_fd)
 104 {
 105    if (!shim_fd)
 106       shim_fd = drm_shim_file_create(fd);
 107
 108    _mesa_hash_table_insert(shim_device.fd_map, (void *)(uintptr_t)(fd + 1), shim_fd);
 109 }
 110
 111 struct shim_fd *
 112 drm_shim_fd_lookup(int fd)
 113 {
 114    if (fd == -1)
 115       return NULL;
 116
 117    struct hash_entry *entry =
 118       _mesa_hash_table_search(shim_device.fd_map, (void *)(uintptr_t)(fd + 1));
 119
 120    if (!entry)
 121       return NULL;
 122    return entry->data;
 123 }
 124
 125 /* ioctl used by drmGetVersion() */
 126 static int
 127 drm_shim_ioctl_version(int fd, unsigned long request, void *arg)
 128 {
 129    struct drm_version *args = arg;
 130    const char *date = "20190320";
 131    const char *desc = "shim";
 132
 133    args->version_major = shim_device.version_major;
 134    args->version_minor = shim_device.version_minor;
 135    args->version_patchlevel = shim_device.version_patchlevel;
 136
 137    if (args->name)
 138       strncpy(args->name, shim_device.driver_name, args->name_len);
 139    if (args->date)
 140       strncpy(args->date, date, args->date_len);
 141    if (args->desc)
 142       strncpy(args->desc, desc, args->desc_len);
 143    args->name_len = strlen(shim_device.driver_name);
 144    args->date_len = strlen(date);
 145    args->desc_len = strlen(desc);
 146
 147    return 0;
 148 }
 149
 150 static int
 151 drm_shim_ioctl_get_cap(int fd, unsigned long request, void *arg)
 152 {
 153    struct drm_get_cap *gc = arg;
 154
 155    switch (gc->capability) {
 156    case DRM_CAP_PRIME:
 157    case DRM_CAP_SYNCOBJ:
 158       gc->value = 1;
 159       return 0;
 160
 161    default:
 162       fprintf(stderr, "DRM_IOCTL_GET_CAP: unhandled 0x%x\n",
 163               (int)gc->capability);
 164       return -1;
 165    }
 166 }
 167
 168 static int
 169 drm_shim_ioctl_gem_close(int fd, unsigned long request, void *arg)
 170 {
 171    struct shim_fd *shim_fd = drm_shim_fd_lookup(fd);
 172    struct drm_gem_close *c = arg;
 173
 174    if (!c->handle)
 175       return 0;
 176
 177    mtx_lock(&handle_lock);
 178    struct hash_entry *entry =
 179       _mesa_hash_table_search(shim_fd->handles, (void *)(uintptr_t)c->handle);
 180    if (!entry) {
 181       mtx_unlock(&handle_lock);
 182       return -EINVAL;
 183    }
 184
 185    struct shim_bo *bo = entry->data;
 186    _mesa_hash_table_remove(shim_fd->handles, entry);
 187    drm_shim_bo_put(bo);
 188    mtx_unlock(&handle_lock);
 189    return 0;
 190 }
 191
 192 static int
 193 drm_shim_ioctl_stub(int fd, unsigned long request, void *arg)
 194 {
 195    return 0;
 196 }
 197
 198 ioctl_fn_t core_ioctls[] = {
 199    [_IOC_NR(DRM_IOCTL_VERSION)] = drm_shim_ioctl_version,
 200    [_IOC_NR(DRM_IOCTL_GET_CAP)] = drm_shim_ioctl_get_cap,
 201    [_IOC_NR(DRM_IOCTL_GEM_CLOSE)] = drm_shim_ioctl_gem_close,
 202    [_IOC_NR(DRM_IOCTL_SYNCOBJ_CREATE)] = drm_shim_ioctl_stub,
 203    [_IOC_NR(DRM_IOCTL_SYNCOBJ_DESTROY)] = drm_shim_ioctl_stub,
 204    [_IOC_NR(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD)] = drm_shim_ioctl_stub,
 205    [_IOC_NR(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE)] = drm_shim_ioctl_stub,
 206 };
 207
 208 /**
 209  * Implements the GEM core ioctls, and calls into driver-specific ioctls.
 210  */
 211 int
 212 drm_shim_ioctl(int fd, unsigned long request, void *arg)
 213 {
 214    int type = _IOC_TYPE(request);
 215    int nr = _IOC_NR(request);
 216
 217    assert(type == DRM_IOCTL_BASE);
 218
 219    if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END) {
 220       int driver_nr = nr - DRM_COMMAND_BASE;
 221
 222       if (driver_nr < shim_device.driver_ioctl_count &&
 223           shim_device.driver_ioctls[driver_nr]) {
 224          return shim_device.driver_ioctls[driver_nr](fd, request, arg);
 225       }
 226    } else {
 227       if (nr < ARRAY_SIZE(core_ioctls) && core_ioctls[nr]) {
 228          return core_ioctls[nr](fd, request, arg);
 229       }
 230    }
 231
 232    if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END) {
 233       fprintf(stderr,
 234               "DRM_SHIM: unhandled driver DRM ioctl %d (0x%08lx)\n",
 235               nr - DRM_COMMAND_BASE, request);
 236    } else {
 237       fprintf(stderr,
 238               "DRM_SHIM: unhandled core DRM ioctl 0x%X (0x%08lx)\n",
 239               nr, request);
 240    }
 241
 242    abort();
 243 }
 244
 245 void
 246 drm_shim_bo_init(struct shim_bo *bo, size_t size)
 247 {
 248    bo->size = size;
 249    bo->fd = memfd_create("shim bo", MFD_CLOEXEC);
 250    if (bo->fd == -1) {
 251       fprintf(stderr, "Failed to create BO: %s\n", strerror(errno));
 252       abort();
 253    }
 254
 255    if (ftruncate(bo->fd, size) == -1) {
 256       fprintf(stderr, "Failed to size BO: %s\n", strerror(errno));
 257       abort();
 258    }
 259 }
 260
 261 struct shim_bo *
 262 drm_shim_bo_lookup(struct shim_fd *shim_fd, int handle)
 263 {
 264    if (!handle)
 265       return NULL;
 266
 267    mtx_lock(&handle_lock);
 268    struct hash_entry *entry =
 269       _mesa_hash_table_search(shim_fd->handles, (void *)(uintptr_t)handle);
 270    struct shim_bo *bo = entry ? entry->data : NULL;
 271    mtx_unlock(&handle_lock);
 272
 273    if (bo)
 274       p_atomic_inc(&bo->refcount);
 275
 276    return bo;
 277 }
 278
 279 void
 280 drm_shim_bo_get(struct shim_bo *bo)
 281 {
 282    p_atomic_inc(&bo->refcount);
 283 }
 284
 285 void
 286 drm_shim_bo_put(struct shim_bo *bo)
 287 {
 288    if (p_atomic_dec_return(&bo->refcount) == 0)
 289       return;
 290
 291    if (shim_device.driver_bo_free)
 292       shim_device.driver_bo_free(bo);
 293    close(bo->fd);
 294    free(bo);
 295 }
 296
 297 int
 298 drm_shim_bo_get_handle(struct shim_fd *shim_fd, struct shim_bo *bo)
 299 {
 300    /* We should probably have some real datastructure for finding the free
 301     * number.
 302     */
 303    mtx_lock(&handle_lock);
 304    for (int new_handle = 1; ; new_handle++) {
 305       void *key = (void *)(uintptr_t)new_handle;
 306       if (!_mesa_hash_table_search(shim_fd->handles, key)) {
 307          drm_shim_bo_get(bo);
 308          _mesa_hash_table_insert(shim_fd->handles, key, bo);
 309          mtx_unlock(&handle_lock);
 310          return new_handle;
 311       }
 312    }
 313    mtx_unlock(&handle_lock);
 314
 315    return 0;
 316 }
 317
 318 /* Creates an mmap offset for the BO in the DRM fd.
 319  *
 320  * XXX: We should be maintaining a u_mm allocator where the mmap offsets
 321  * allocate the size of the BO and it can be used to look the BO back up.
 322  * Instead, we just stuff the shim's pointer as the return value, and treat
 323  * the incoming mmap offset on the DRM fd as a BO pointer.  This doesn't work
 324  * if someone tries to map a subset of the BO, but it's enough to get V3D
 325  * working for now.
 326  */
 327 uint64_t
 328 drm_shim_bo_get_mmap_offset(struct shim_fd *shim_fd, struct shim_bo *bo)
 329 {
 330    return (uintptr_t)bo;
 331 }
 332
 333 /* For mmap() on the DRM fd, look up the BO from the "offset" and map the BO's
 334  * fd.
 335  */
 336 void *
 337 drm_shim_mmap(struct shim_fd *shim_fd, size_t length, int prot, int flags,
 338               int fd, off_t offset)
 339 {
 340    struct shim_bo *bo = (void *)(uintptr_t)offset;
 341
 342    return mmap(NULL, length, prot, flags, bo->fd, 0);
 343 }