drivers/gpu/drm/exynos/exynos_drm_gem.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* exynos_drm_gem.c
   3  *
   4  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
   5  * Author: Inki Dae <inki.dae@samsung.com>
   6  */
   7
   8
   9 #include <linux/dma-buf.h>
  10 #include <linux/pfn_t.h>
  11 #include <linux/shmem_fs.h>
  12 #include <linux/module.h>
  13
  14 #include <drm/drm_prime.h>
  15 #include <drm/drm_vma_manager.h>
  16 #include <drm/exynos_drm.h>
  17
  18 #include "exynos_drm_drv.h"
  19 #include "exynos_drm_gem.h"
  20
  21 MODULE_IMPORT_NS("DMA_BUF");
  22
  23 static int exynos_drm_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
  24
  25 static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem, bool kvmap)
  26 {
  27         struct drm_device *dev = exynos_gem->base.dev;
  28         unsigned long attr = 0;
  29
  30         if (exynos_gem->dma_addr) {
  31                 DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "already allocated.\n");
  32                 return 0;
  33         }
  34
  35         /*
  36          * if EXYNOS_BO_CONTIG, fully physically contiguous memory
  37          * region will be allocated else physically contiguous
  38          * as possible.
  39          */
  40         if (!(exynos_gem->flags & EXYNOS_BO_NONCONTIG))
  41                 attr |= DMA_ATTR_FORCE_CONTIGUOUS;
  42
  43         /*
  44          * if EXYNOS_BO_WC or EXYNOS_BO_NONCACHABLE, writecombine mapping
  45          * else cachable mapping.
  46          */
  47         if (exynos_gem->flags & EXYNOS_BO_WC ||
  48                         !(exynos_gem->flags & EXYNOS_BO_CACHABLE))
  49                 attr |= DMA_ATTR_WRITE_COMBINE;
  50
  51         /* FBDev emulation requires kernel mapping */
  52         if (!kvmap)
  53                 attr |= DMA_ATTR_NO_KERNEL_MAPPING;
  54
  55         exynos_gem->dma_attrs = attr;
  56         exynos_gem->cookie = dma_alloc_attrs(to_dma_dev(dev), exynos_gem->size,
  57                                              &exynos_gem->dma_addr, GFP_KERNEL,
  58                                              exynos_gem->dma_attrs);
  59         if (!exynos_gem->cookie) {
  60                 DRM_DEV_ERROR(to_dma_dev(dev), "failed to allocate buffer.\n");
  61                 return -ENOMEM;
  62         }
  63
  64         if (kvmap)
  65                 exynos_gem->kvaddr = exynos_gem->cookie;
  66
  67         DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "dma_addr(0x%lx), size(0x%lx)\n",
  68                         (unsigned long)exynos_gem->dma_addr, exynos_gem->size);
  69         return 0;
  70 }
  71
  72 static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
  73 {
  74         struct drm_device *dev = exynos_gem->base.dev;
  75
  76         if (!exynos_gem->dma_addr) {
  77                 DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr is invalid.\n");
  78                 return;
  79         }
  80
  81         DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr(0x%lx), size(0x%lx)\n",
  82                         (unsigned long)exynos_gem->dma_addr, exynos_gem->size);
  83
  84         dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
  85                         (dma_addr_t)exynos_gem->dma_addr,
  86                         exynos_gem->dma_attrs);
  87 }
  88
  89 static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
  90                                         struct drm_file *file_priv,
  91                                         unsigned int *handle)
  92 {
  93         int ret;
  94
  95         /*
  96          * allocate a id of idr table where the obj is registered
  97          * and handle has the id what user can see.
  98          */
  99         ret = drm_gem_handle_create(file_priv, obj, handle);
 100         if (ret)
 101                 return ret;
 102
 103         DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "gem handle = 0x%x\n", *handle);
 104
 105         /* drop reference from allocate - handle holds it now. */
 106         drm_gem_object_put(obj);
 107
 108         return 0;
 109 }
 110
 111 void exynos_drm_gem_destroy(struct exynos_drm_gem *exynos_gem)
 112 {
 113         struct drm_gem_object *obj = &exynos_gem->base;
 114
 115         DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "handle count = %d\n",
 116                           obj->handle_count);
 117
 118         /*
 119          * do not release memory region from exporter.
 120          *
 121          * the region will be released by exporter
 122          * once dmabuf's refcount becomes 0.
 123          */
 124         if (obj->import_attach)
 125                 drm_prime_gem_destroy(obj, exynos_gem->sgt);
 126         else
 127                 exynos_drm_free_buf(exynos_gem);
 128
 129         /* release file pointer to gem object. */
 130         drm_gem_object_release(obj);
 131
 132         kfree(exynos_gem);
 133 }
 134
 135 static const struct vm_operations_struct exynos_drm_gem_vm_ops = {
 136         .open = drm_gem_vm_open,
 137         .close = drm_gem_vm_close,
 138 };
 139
 140 static const struct drm_gem_object_funcs exynos_drm_gem_object_funcs = {
 141         .free = exynos_drm_gem_free_object,
 142         .get_sg_table = exynos_drm_gem_prime_get_sg_table,
 143         .mmap = exynos_drm_gem_mmap,
 144         .vm_ops = &exynos_drm_gem_vm_ops,
 145 };
 146
 147 static struct exynos_drm_gem *exynos_drm_gem_init(struct drm_device *dev,
 148                                                   unsigned long size)
 149 {
 150         struct exynos_drm_gem *exynos_gem;
 151         struct drm_gem_object *obj;
 152         int ret;
 153
 154         exynos_gem = kzalloc(sizeof(*exynos_gem), GFP_KERNEL);
 155         if (!exynos_gem)
 156                 return ERR_PTR(-ENOMEM);
 157
 158         exynos_gem->size = size;
 159         obj = &exynos_gem->base;
 160
 161         obj->funcs = &exynos_drm_gem_object_funcs;
 162
 163         ret = drm_gem_object_init(dev, obj, size);
 164         if (ret < 0) {
 165                 DRM_DEV_ERROR(dev->dev, "failed to initialize gem object\n");
 166                 kfree(exynos_gem);
 167                 return ERR_PTR(ret);
 168         }
 169
 170         ret = drm_gem_create_mmap_offset(obj);
 171         if (ret < 0) {
 172                 drm_gem_object_release(obj);
 173                 kfree(exynos_gem);
 174                 return ERR_PTR(ret);
 175         }
 176
 177         DRM_DEV_DEBUG_KMS(dev->dev, "created file object = %pK\n", obj->filp);
 178
 179         return exynos_gem;
 180 }
 181
 182 struct exynos_drm_gem *exynos_drm_gem_create(struct drm_device *dev,
 183                                              unsigned int flags,
 184                                              unsigned long size,
 185                                              bool kvmap)
 186 {
 187         struct exynos_drm_gem *exynos_gem;
 188         int ret;
 189
 190         if (flags & ~(EXYNOS_BO_MASK)) {
 191                 DRM_DEV_ERROR(dev->dev,
 192                               "invalid GEM buffer flags: %u\n", flags);
 193                 return ERR_PTR(-EINVAL);
 194         }
 195
 196         if (!size) {
 197                 DRM_DEV_ERROR(dev->dev, "invalid GEM buffer size: %lu\n", size);
 198                 return ERR_PTR(-EINVAL);
 199         }
 200
 201         size = roundup(size, PAGE_SIZE);
 202
 203         exynos_gem = exynos_drm_gem_init(dev, size);
 204         if (IS_ERR(exynos_gem))
 205                 return exynos_gem;
 206
 207         if (!is_drm_iommu_supported(dev) && (flags & EXYNOS_BO_NONCONTIG)) {
 208                 /*
 209                  * when no IOMMU is available, all allocated buffers are
 210                  * contiguous anyway, so drop EXYNOS_BO_NONCONTIG flag
 211                  */
 212                 flags &= ~EXYNOS_BO_NONCONTIG;
 213                 DRM_WARN("Non-contiguous allocation is not supported without IOMMU, falling back to contiguous buffer\n");
 214         }
 215
 216         /* set memory type and cache attribute from user side. */
 217         exynos_gem->flags = flags;
 218
 219         ret = exynos_drm_alloc_buf(exynos_gem, kvmap);
 220         if (ret < 0) {
 221                 drm_gem_object_release(&exynos_gem->base);
 222                 kfree(exynos_gem);
 223                 return ERR_PTR(ret);
 224         }
 225
 226         return exynos_gem;
 227 }
 228
 229 int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
 230                                 struct drm_file *file_priv)
 231 {
 232         struct drm_exynos_gem_create *args = data;
 233         struct exynos_drm_gem *exynos_gem;
 234         int ret;
 235
 236         exynos_gem = exynos_drm_gem_create(dev, args->flags, args->size, false);
 237         if (IS_ERR(exynos_gem))
 238                 return PTR_ERR(exynos_gem);
 239
 240         ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
 241                                            &args->handle);
 242         if (ret) {
 243                 exynos_drm_gem_destroy(exynos_gem);
 244                 return ret;
 245         }
 246
 247         return 0;
 248 }
 249
 250 int exynos_drm_gem_map_ioctl(struct drm_device *dev, void *data,
 251                              struct drm_file *file_priv)
 252 {
 253         struct drm_exynos_gem_map *args = data;
 254
 255         return drm_gem_dumb_map_offset(file_priv, dev, args->handle,
 256                                        &args->offset);
 257 }
 258
 259 struct exynos_drm_gem *exynos_drm_gem_get(struct drm_file *filp,
 260                                           unsigned int gem_handle)
 261 {
 262         struct drm_gem_object *obj;
 263
 264         obj = drm_gem_object_lookup(filp, gem_handle);
 265         if (!obj)
 266                 return NULL;
 267         return to_exynos_gem(obj);
 268 }
 269
 270 static int exynos_drm_gem_mmap_buffer(struct exynos_drm_gem *exynos_gem,
 271                                       struct vm_area_struct *vma)
 272 {
 273         struct drm_device *drm_dev = exynos_gem->base.dev;
 274         unsigned long vm_size;
 275         int ret;
 276
 277         vm_flags_clear(vma, VM_PFNMAP);
 278         vma->vm_pgoff = 0;
 279
 280         vm_size = vma->vm_end - vma->vm_start;
 281
 282         /* check if user-requested size is valid. */
 283         if (vm_size > exynos_gem->size)
 284                 return -EINVAL;
 285
 286         ret = dma_mmap_attrs(to_dma_dev(drm_dev), vma, exynos_gem->cookie,
 287                              exynos_gem->dma_addr, exynos_gem->size,
 288                              exynos_gem->dma_attrs);
 289         if (ret < 0) {
 290                 DRM_ERROR("failed to mmap.\n");
 291                 return ret;
 292         }
 293
 294         return 0;
 295 }
 296
 297 int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
 298                                       struct drm_file *file_priv)
 299 {
 300         struct exynos_drm_gem *exynos_gem;
 301         struct drm_exynos_gem_info *args = data;
 302         struct drm_gem_object *obj;
 303
 304         obj = drm_gem_object_lookup(file_priv, args->handle);
 305         if (!obj) {
 306                 DRM_DEV_ERROR(dev->dev, "failed to lookup gem object.\n");
 307                 return -EINVAL;
 308         }
 309
 310         exynos_gem = to_exynos_gem(obj);
 311
 312         args->flags = exynos_gem->flags;
 313         args->size = exynos_gem->size;
 314
 315         drm_gem_object_put(obj);
 316
 317         return 0;
 318 }
 319
 320 void exynos_drm_gem_free_object(struct drm_gem_object *obj)
 321 {
 322         exynos_drm_gem_destroy(to_exynos_gem(obj));
 323 }
 324
 325 int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
 326                                struct drm_device *dev,
 327                                struct drm_mode_create_dumb *args)
 328 {
 329         struct exynos_drm_gem *exynos_gem;
 330         unsigned int flags;
 331         int ret;
 332
 333         /*
 334          * allocate memory to be used for framebuffer.
 335          * - this callback would be called by user application
 336          *      with DRM_IOCTL_MODE_CREATE_DUMB command.
 337          */
 338
 339         args->pitch = args->width * ((args->bpp + 7) / 8);
 340         args->size = args->pitch * args->height;
 341
 342         if (is_drm_iommu_supported(dev))
 343                 flags = EXYNOS_BO_NONCONTIG | EXYNOS_BO_WC;
 344         else
 345                 flags = EXYNOS_BO_CONTIG | EXYNOS_BO_WC;
 346
 347         exynos_gem = exynos_drm_gem_create(dev, flags, args->size, false);
 348         if (IS_ERR(exynos_gem)) {
 349                 dev_warn(dev->dev, "FB allocation failed.\n");
 350                 return PTR_ERR(exynos_gem);
 351         }
 352
 353         ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
 354                                            &args->handle);
 355         if (ret) {
 356                 exynos_drm_gem_destroy(exynos_gem);
 357                 return ret;
 358         }
 359
 360         return 0;
 361 }
 362
 363 static int exynos_drm_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 364 {
 365         struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
 366         int ret;
 367
 368         if (obj->import_attach)
 369                 return dma_buf_mmap(obj->dma_buf, vma, 0);
 370
 371         vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
 372
 373         DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "flags = 0x%x\n",
 374                           exynos_gem->flags);
 375
 376         /* non-cachable as default. */
 377         if (exynos_gem->flags & EXYNOS_BO_CACHABLE)
 378                 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 379         else if (exynos_gem->flags & EXYNOS_BO_WC)
 380                 vma->vm_page_prot =
 381                         pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 382         else
 383                 vma->vm_page_prot =
 384                         pgprot_noncached(vm_get_page_prot(vma->vm_flags));
 385
 386         ret = exynos_drm_gem_mmap_buffer(exynos_gem, vma);
 387         if (ret)
 388                 goto err_close_vm;
 389
 390         return ret;
 391
 392 err_close_vm:
 393         drm_gem_vm_close(vma);
 394
 395         return ret;
 396 }
 397
 398 /* low-level interface prime helpers */
 399 struct drm_gem_object *exynos_drm_gem_prime_import(struct drm_device *dev,
 400                                             struct dma_buf *dma_buf)
 401 {
 402         return drm_gem_prime_import_dev(dev, dma_buf, to_dma_dev(dev));
 403 }
 404
 405 struct sg_table *exynos_drm_gem_prime_get_sg_table(struct drm_gem_object *obj)
 406 {
 407         struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
 408         struct drm_device *drm_dev = obj->dev;
 409         struct sg_table *sgt;
 410         int ret;
 411
 412         sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 413         if (!sgt)
 414                 return ERR_PTR(-ENOMEM);
 415
 416         ret = dma_get_sgtable_attrs(to_dma_dev(drm_dev), sgt, exynos_gem->cookie,
 417                                     exynos_gem->dma_addr, exynos_gem->size,
 418                                     exynos_gem->dma_attrs);
 419         if (ret) {
 420                 DRM_ERROR("failed to get sgtable, %d\n", ret);
 421                 kfree(sgt);
 422                 return ERR_PTR(ret);
 423         }
 424
 425         return sgt;
 426 }
 427
 428 struct drm_gem_object *
 429 exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
 430                                      struct dma_buf_attachment *attach,
 431                                      struct sg_table *sgt)
 432 {
 433         struct exynos_drm_gem *exynos_gem;
 434
 435         /* check if the entries in the sg_table are contiguous */
 436         if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size) {
 437                 DRM_ERROR("buffer chunks must be mapped contiguously");
 438                 return ERR_PTR(-EINVAL);
 439         }
 440
 441         exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
 442         if (IS_ERR(exynos_gem))
 443                 return ERR_CAST(exynos_gem);
 444
 445         /*
 446          * Buffer has been mapped as contiguous into DMA address space,
 447          * but if there is IOMMU, it can be either CONTIG or NONCONTIG.
 448          * We assume a simplified logic below:
 449          */
 450         if (is_drm_iommu_supported(dev))
 451                 exynos_gem->flags |= EXYNOS_BO_NONCONTIG;
 452         else
 453                 exynos_gem->flags |= EXYNOS_BO_CONTIG;
 454
 455         exynos_gem->dma_addr = sg_dma_address(sgt->sgl);
 456         exynos_gem->sgt = sgt;
 457         return &exynos_gem->base;
 458 }