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    if (args->name)
 134       strncpy(args->name, shim_device.driver_name, args->name_len);
 135    if (args->date)
 136       strncpy(args->date, date, args->date_len);
 137    if (args->desc)
 138       strncpy(args->desc, desc, args->desc_len);
 139    args->name_len = strlen(shim_device.driver_name);
 140    args->date_len = strlen(date);
 141    args->desc_len = strlen(desc);
 142
 143    return 0;
 144 }
 145
 146 static int
 147 drm_shim_ioctl_get_cap(int fd, unsigned long request, void *arg)
 148 {
 149    struct drm_get_cap *gc = arg;
 150
 151    switch (gc->capability) {
 152    case DRM_CAP_PRIME:
 153    case DRM_CAP_SYNCOBJ:
 154       gc->value = 1;
 155       return 0;
 156
 157    default:
 158       fprintf(stderr, "DRM_IOCTL_GET_CAP: unhandled 0x%x\n",
 159               (int)gc->capability);
 160       return -1;
 161    }
 162 }
 163
 164 static int
 165 drm_shim_ioctl_gem_close(int fd, unsigned long request, void *arg)
 166 {
 167    struct shim_fd *shim_fd = drm_shim_fd_lookup(fd);
 168    struct drm_gem_close *c = arg;
 169
 170    if (!c->handle)
 171       return 0;
 172
 173    mtx_lock(&handle_lock);
 174    struct hash_entry *entry =
 175       _mesa_hash_table_search(shim_fd->handles, (void *)(uintptr_t)c->handle);
 176    if (!entry) {
 177       mtx_unlock(&handle_lock);
 178       return -EINVAL;
 179    }
 180
 181    struct shim_bo *bo = entry->data;
 182    _mesa_hash_table_remove(shim_fd->handles, entry);
 183    drm_shim_bo_put(bo);
 184    mtx_unlock(&handle_lock);
 185    return 0;
 186 }
 187
 188 static int
 189 drm_shim_ioctl_stub(int fd, unsigned long request, void *arg)
 190 {
 191    return 0;
 192 }
 193
 194 ioctl_fn_t core_ioctls[] = {
 195    [_IOC_NR(DRM_IOCTL_VERSION)] = drm_shim_ioctl_version,
 196    [_IOC_NR(DRM_IOCTL_GET_CAP)] = drm_shim_ioctl_get_cap,
 197    [_IOC_NR(DRM_IOCTL_GEM_CLOSE)] = drm_shim_ioctl_gem_close,
 198    [_IOC_NR(DRM_IOCTL_SYNCOBJ_CREATE)] = drm_shim_ioctl_stub,
 199    [_IOC_NR(DRM_IOCTL_SYNCOBJ_DESTROY)] = drm_shim_ioctl_stub,
 200    [_IOC_NR(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD)] = drm_shim_ioctl_stub,
 201    [_IOC_NR(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE)] = drm_shim_ioctl_stub,
 202 };
 203
 204 /**
 205  * Implements the GEM core ioctls, and calls into driver-specific ioctls.
 206  */
 207 int
 208 drm_shim_ioctl(int fd, unsigned long request, void *arg)
 209 {
 210    int type = _IOC_TYPE(request);
 211    int nr = _IOC_NR(request);
 212
 213    assert(type == DRM_IOCTL_BASE);
 214
 215    if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END) {
 216       int driver_nr = nr - DRM_COMMAND_BASE;
 217
 218       if (driver_nr < shim_device.driver_ioctl_count &&
 219           shim_device.driver_ioctls[driver_nr]) {
 220          return shim_device.driver_ioctls[driver_nr](fd, request, arg);
 221       }
 222    } else {
 223       if (nr < ARRAY_SIZE(core_ioctls) && core_ioctls[nr]) {
 224          return core_ioctls[nr](fd, request, arg);
 225       }
 226    }
 227
 228    if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END) {
 229       fprintf(stderr,
 230               "DRM_SHIM: unhandled driver DRM ioctl %d (0x%08lx)\n",
 231               nr - DRM_COMMAND_BASE, request);
 232    } else {
 233       fprintf(stderr,
 234               "DRM_SHIM: unhandled core DRM ioctl 0x%X (0x%08lx)\n",
 235               nr, request);
 236    }
 237
 238    abort();
 239 }
 240
 241 void
 242 drm_shim_bo_init(struct shim_bo *bo, size_t size)
 243 {
 244    bo->size = size;
 245    bo->fd = memfd_create("shim bo", MFD_CLOEXEC);
 246    if (bo->fd == -1) {
 247       fprintf(stderr, "Failed to create BO: %s\n", strerror(errno));
 248       abort();
 249    }
 250
 251    if (ftruncate(bo->fd, size) == -1) {
 252       fprintf(stderr, "Failed to size BO: %s\n", strerror(errno));
 253       abort();
 254    }
 255 }
 256
 257 struct shim_bo *
 258 drm_shim_bo_lookup(struct shim_fd *shim_fd, int handle)
 259 {
 260    if (!handle)
 261       return NULL;
 262
 263    mtx_lock(&handle_lock);
 264    struct hash_entry *entry =
 265       _mesa_hash_table_search(shim_fd->handles, (void *)(uintptr_t)handle);
 266    struct shim_bo *bo = entry ? entry->data : NULL;
 267    mtx_unlock(&handle_lock);
 268
 269    if (bo)
 270       p_atomic_inc(&bo->refcount);
 271
 272    return bo;
 273 }
 274
 275 void
 276 drm_shim_bo_get(struct shim_bo *bo)
 277 {
 278    p_atomic_inc(&bo->refcount);
 279 }
 280
 281 void
 282 drm_shim_bo_put(struct shim_bo *bo)
 283 {
 284    if (p_atomic_dec_return(&bo->refcount) == 0)
 285       return;
 286
 287    if (shim_device.driver_bo_free)
 288       shim_device.driver_bo_free(bo);
 289    close(bo->fd);
 290    free(bo);
 291 }
 292
 293 int
 294 drm_shim_bo_get_handle(struct shim_fd *shim_fd, struct shim_bo *bo)
 295 {
 296    /* We should probably have some real datastructure for finding the free
 297     * number.
 298     */
 299    mtx_lock(&handle_lock);
 300    for (int new_handle = 1; ; new_handle++) {
 301       void *key = (void *)(uintptr_t)new_handle;
 302       if (!_mesa_hash_table_search(shim_fd->handles, key)) {
 303          drm_shim_bo_get(bo);
 304          _mesa_hash_table_insert(shim_fd->handles, key, bo);
 305          mtx_unlock(&handle_lock);
 306          return new_handle;
 307       }
 308    }
 309    mtx_unlock(&handle_lock);
 310
 311    return 0;
 312 }
 313
 314 /* Creates an mmap offset for the BO in the DRM fd.
 315  *
 316  * XXX: We should be maintaining a u_mm allocator where the mmap offsets
 317  * allocate the size of the BO and it can be used to look the BO back up.
 318  * Instead, we just stuff the shim's pointer as the return value, and treat
 319  * the incoming mmap offset on the DRM fd as a BO pointer.  This doesn't work
 320  * if someone tries to map a subset of the BO, but it's enough to get V3D
 321  * working for now.
 322  */
 323 uint64_t
 324 drm_shim_bo_get_mmap_offset(struct shim_fd *shim_fd, struct shim_bo *bo)
 325 {
 326    return (uintptr_t)bo;
 327 }
 328
 329 /* For mmap() on the DRM fd, look up the BO from the "offset" and map the BO's
 330  * fd.
 331  */
 332 void *
 333 drm_shim_mmap(struct shim_fd *shim_fd, size_t length, int prot, int flags,
 334               int fd, off_t offset)
 335 {
 336    struct shim_bo *bo = (void *)(uintptr_t)offset;
 337
 338    return mmap(NULL, length, prot, flags, bo->fd, 0);
 339 }