drivers/gpu/drm/msm/msm_gem.c

   1 /*
   2  * Copyright (C) 2013 Red Hat
   3  * Author: Rob Clark <robdclark@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/spinlock.h>
  19 #include <linux/shmem_fs.h>
  20
  21 #include "msm_drv.h"
  22 #include "msm_gem.h"
  23
  24
  25 /* called with dev->struct_mutex held */
  26 static struct page **get_pages(struct drm_gem_object *obj)
  27 {
  28         struct msm_gem_object *msm_obj = to_msm_bo(obj);
  29
  30         if (!msm_obj->pages) {
  31                 struct drm_device *dev = obj->dev;
  32                 struct page **p = drm_gem_get_pages(obj, 0);
  33                 int npages = obj->size >> PAGE_SHIFT;
  34
  35                 if (IS_ERR(p)) {
  36                         dev_err(dev->dev, "could not get pages: %ld\n",
  37                                         PTR_ERR(p));
  38                         return p;
  39                 }
  40
  41                 msm_obj->sgt = drm_prime_pages_to_sg(p, npages);
  42                 if (!msm_obj->sgt) {
  43                         dev_err(dev->dev, "failed to allocate sgt\n");
  44                         return ERR_PTR(-ENOMEM);
  45                 }
  46
  47                 msm_obj->pages = p;
  48
  49                 /* For non-cached buffers, ensure the new pages are clean
  50                  * because display controller, GPU, etc. are not coherent:
  51                  */
  52                 if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
  53                         dma_map_sg(dev->dev, msm_obj->sgt->sgl,
  54                                         msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
  55         }
  56
  57         return msm_obj->pages;
  58 }
  59
  60 static void put_pages(struct drm_gem_object *obj)
  61 {
  62         struct msm_gem_object *msm_obj = to_msm_bo(obj);
  63
  64         if (msm_obj->pages) {
  65                 /* For non-cached buffers, ensure the new pages are clean
  66                  * because display controller, GPU, etc. are not coherent:
  67                  */
  68                 if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
  69                         dma_unmap_sg(obj->dev->dev, msm_obj->sgt->sgl,
  70                                         msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
  71                 sg_free_table(msm_obj->sgt);
  72                 kfree(msm_obj->sgt);
  73
  74                 drm_gem_put_pages(obj, msm_obj->pages, true, false);
  75                 msm_obj->pages = NULL;
  76         }
  77 }
  78
  79 int msm_gem_mmap_obj(struct drm_gem_object *obj,
  80                 struct vm_area_struct *vma)
  81 {
  82         struct msm_gem_object *msm_obj = to_msm_bo(obj);
  83
  84         vma->vm_flags &= ~VM_PFNMAP;
  85         vma->vm_flags |= VM_MIXEDMAP;
  86
  87         if (msm_obj->flags & MSM_BO_WC) {
  88                 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
  89         } else if (msm_obj->flags & MSM_BO_UNCACHED) {
  90                 vma->vm_page_prot = pgprot_noncached(vm_get_page_prot(vma->vm_flags));
  91         } else {
  92                 /*
  93                  * Shunt off cached objs to shmem file so they have their own
  94                  * address_space (so unmap_mapping_range does what we want,
  95                  * in particular in the case of mmap'd dmabufs)
  96                  */
  97                 fput(vma->vm_file);
  98                 get_file(obj->filp);
  99                 vma->vm_pgoff = 0;
 100                 vma->vm_file  = obj->filp;
 101
 102                 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 103         }
 104
 105         return 0;
 106 }
 107
 108 int msm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 109 {
 110         int ret;
 111
 112         ret = drm_gem_mmap(filp, vma);
 113         if (ret) {
 114                 DBG("mmap failed: %d", ret);
 115                 return ret;
 116         }
 117
 118         return msm_gem_mmap_obj(vma->vm_private_data, vma);
 119 }
 120
 121 int msm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 122 {
 123         struct drm_gem_object *obj = vma->vm_private_data;
 124         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 125         struct drm_device *dev = obj->dev;
 126         struct page **pages;
 127         unsigned long pfn;
 128         pgoff_t pgoff;
 129         int ret;
 130
 131         /* Make sure we don't parallel update on a fault, nor move or remove
 132          * something from beneath our feet
 133          */
 134         ret = mutex_lock_interruptible(&dev->struct_mutex);
 135         if (ret)
 136                 goto out;
 137
 138         /* make sure we have pages attached now */
 139         pages = get_pages(obj);
 140         if (IS_ERR(pages)) {
 141                 ret = PTR_ERR(pages);
 142                 goto out_unlock;
 143         }
 144
 145         /* We don't use vmf->pgoff since that has the fake offset: */
 146         pgoff = ((unsigned long)vmf->virtual_address -
 147                         vma->vm_start) >> PAGE_SHIFT;
 148
 149         pfn = page_to_pfn(msm_obj->pages[pgoff]);
 150
 151         VERB("Inserting %p pfn %lx, pa %lx", vmf->virtual_address,
 152                         pfn, pfn << PAGE_SHIFT);
 153
 154         ret = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address, pfn);
 155
 156 out_unlock:
 157         mutex_unlock(&dev->struct_mutex);
 158 out:
 159         switch (ret) {
 160         case -EAGAIN:
 161                 set_need_resched();
 162         case 0:
 163         case -ERESTARTSYS:
 164         case -EINTR:
 165                 return VM_FAULT_NOPAGE;
 166         case -ENOMEM:
 167                 return VM_FAULT_OOM;
 168         default:
 169                 return VM_FAULT_SIGBUS;
 170         }
 171 }
 172
 173 /** get mmap offset */
 174 static uint64_t mmap_offset(struct drm_gem_object *obj)
 175 {
 176         struct drm_device *dev = obj->dev;
 177         int ret;
 178
 179         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 180
 181         /* Make it mmapable */
 182         ret = drm_gem_create_mmap_offset(obj);
 183
 184         if (ret) {
 185                 dev_err(dev->dev, "could not allocate mmap offset\n");
 186                 return 0;
 187         }
 188
 189         return drm_vma_node_offset_addr(&obj->vma_node);
 190 }
 191
 192 uint64_t msm_gem_mmap_offset(struct drm_gem_object *obj)
 193 {
 194         uint64_t offset;
 195         mutex_lock(&obj->dev->struct_mutex);
 196         offset = mmap_offset(obj);
 197         mutex_unlock(&obj->dev->struct_mutex);
 198         return offset;
 199 }
 200
 201 /* helpers for dealing w/ iommu: */
 202 static int map_range(struct iommu_domain *domain, unsigned int iova,
 203                 struct sg_table *sgt, unsigned int len, int prot)
 204 {
 205         struct scatterlist *sg;
 206         unsigned int da = iova;
 207         unsigned int i, j;
 208         int ret;
 209
 210         if (!domain || !sgt)
 211                 return -EINVAL;
 212
 213         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 214                 u32 pa = sg_phys(sg) - sg->offset;
 215                 size_t bytes = sg->length + sg->offset;
 216
 217                 VERB("map[%d]: %08x %08x(%x)", i, iova, pa, bytes);
 218
 219                 ret = iommu_map(domain, da, pa, bytes, prot);
 220                 if (ret)
 221                         goto fail;
 222
 223                 da += bytes;
 224         }
 225
 226         return 0;
 227
 228 fail:
 229         da = iova;
 230
 231         for_each_sg(sgt->sgl, sg, i, j) {
 232                 size_t bytes = sg->length + sg->offset;
 233                 iommu_unmap(domain, da, bytes);
 234                 da += bytes;
 235         }
 236         return ret;
 237 }
 238
 239 static void unmap_range(struct iommu_domain *domain, unsigned int iova,
 240                 struct sg_table *sgt, unsigned int len)
 241 {
 242         struct scatterlist *sg;
 243         unsigned int da = iova;
 244         int i;
 245
 246         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 247                 size_t bytes = sg->length + sg->offset;
 248                 size_t unmapped;
 249
 250                 unmapped = iommu_unmap(domain, da, bytes);
 251                 if (unmapped < bytes)
 252                         break;
 253
 254                 VERB("unmap[%d]: %08x(%x)", i, iova, bytes);
 255
 256                 BUG_ON(!IS_ALIGNED(bytes, PAGE_SIZE));
 257
 258                 da += bytes;
 259         }
 260 }
 261
 262 /* should be called under struct_mutex.. although it can be called
 263  * from atomic context without struct_mutex to acquire an extra
 264  * iova ref if you know one is already held.
 265  *
 266  * That means when I do eventually need to add support for unpinning
 267  * the refcnt counter needs to be atomic_t.
 268  */
 269 int msm_gem_get_iova_locked(struct drm_gem_object *obj, int id,
 270                 uint32_t *iova)
 271 {
 272         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 273         int ret = 0;
 274
 275         if (!msm_obj->domain[id].iova) {
 276                 struct msm_drm_private *priv = obj->dev->dev_private;
 277                 uint32_t offset = (uint32_t)mmap_offset(obj);
 278                 struct page **pages;
 279                 pages = get_pages(obj);
 280                 if (IS_ERR(pages))
 281                         return PTR_ERR(pages);
 282                 // XXX ideally we would not map buffers writable when not needed...
 283                 ret = map_range(priv->iommus[id], offset, msm_obj->sgt,
 284                                 obj->size, IOMMU_READ | IOMMU_WRITE);
 285                 msm_obj->domain[id].iova = offset;
 286         }
 287
 288         if (!ret)
 289                 *iova = msm_obj->domain[id].iova;
 290
 291         return ret;
 292 }
 293
 294 int msm_gem_get_iova(struct drm_gem_object *obj, int id, uint32_t *iova)
 295 {
 296         int ret;
 297         mutex_lock(&obj->dev->struct_mutex);
 298         ret = msm_gem_get_iova_locked(obj, id, iova);
 299         mutex_unlock(&obj->dev->struct_mutex);
 300         return ret;
 301 }
 302
 303 void msm_gem_put_iova(struct drm_gem_object *obj, int id)
 304 {
 305         // XXX TODO ..
 306         // NOTE: probably don't need a _locked() version.. we wouldn't
 307         // normally unmap here, but instead just mark that it could be
 308         // unmapped (if the iova refcnt drops to zero), but then later
 309         // if another _get_iova_locked() fails we can start unmapping
 310         // things that are no longer needed..
 311 }
 312
 313 int msm_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 314                 struct drm_mode_create_dumb *args)
 315 {
 316         args->pitch = align_pitch(args->width, args->bpp);
 317         args->size  = PAGE_ALIGN(args->pitch * args->height);
 318         return msm_gem_new_handle(dev, file, args->size,
 319                         MSM_BO_SCANOUT | MSM_BO_WC, &args->handle);
 320 }
 321
 322 int msm_gem_dumb_destroy(struct drm_file *file, struct drm_device *dev,
 323                 uint32_t handle)
 324 {
 325         /* No special work needed, drop the reference and see what falls out */
 326         return drm_gem_handle_delete(file, handle);
 327 }
 328
 329 int msm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
 330                 uint32_t handle, uint64_t *offset)
 331 {
 332         struct drm_gem_object *obj;
 333         int ret = 0;
 334
 335         /* GEM does all our handle to object mapping */
 336         obj = drm_gem_object_lookup(dev, file, handle);
 337         if (obj == NULL) {
 338                 ret = -ENOENT;
 339                 goto fail;
 340         }
 341
 342         *offset = msm_gem_mmap_offset(obj);
 343
 344         drm_gem_object_unreference_unlocked(obj);
 345
 346 fail:
 347         return ret;
 348 }
 349
 350 void *msm_gem_vaddr_locked(struct drm_gem_object *obj)
 351 {
 352         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 353         WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
 354         if (!msm_obj->vaddr) {
 355                 struct page **pages = get_pages(obj);
 356                 if (IS_ERR(pages))
 357                         return ERR_CAST(pages);
 358                 msm_obj->vaddr = vmap(pages, obj->size >> PAGE_SHIFT,
 359                                 VM_MAP, pgprot_writecombine(PAGE_KERNEL));
 360         }
 361         return msm_obj->vaddr;
 362 }
 363
 364 void *msm_gem_vaddr(struct drm_gem_object *obj)
 365 {
 366         void *ret;
 367         mutex_lock(&obj->dev->struct_mutex);
 368         ret = msm_gem_vaddr_locked(obj);
 369         mutex_unlock(&obj->dev->struct_mutex);
 370         return ret;
 371 }
 372
 373 int msm_gem_queue_inactive_work(struct drm_gem_object *obj,
 374                 struct work_struct *work)
 375 {
 376         struct drm_device *dev = obj->dev;
 377         struct msm_drm_private *priv = dev->dev_private;
 378
 379         /* just a place-holder until we have gpu.. */
 380         queue_work(priv->wq, work);
 381
 382         return 0;
 383 }
 384
 385 #ifdef CONFIG_DEBUG_FS
 386 void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
 387 {
 388         struct drm_device *dev = obj->dev;
 389         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 390         uint64_t off = drm_vma_node_start(&obj->vma_node);
 391
 392         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 393         seq_printf(m, "%08x: %2d (%2d) %08llx %p %d\n",
 394                         msm_obj->flags, obj->name, obj->refcount.refcount.counter,
 395                         off, msm_obj->vaddr, obj->size);
 396 }
 397
 398 void msm_gem_describe_objects(struct list_head *list, struct seq_file *m)
 399 {
 400         struct msm_gem_object *msm_obj;
 401         int count = 0;
 402         size_t size = 0;
 403
 404         list_for_each_entry(msm_obj, list, mm_list) {
 405                 struct drm_gem_object *obj = &msm_obj->base;
 406                 seq_printf(m, "   ");
 407                 msm_gem_describe(obj, m);
 408                 count++;
 409                 size += obj->size;
 410         }
 411
 412         seq_printf(m, "Total %d objects, %zu bytes\n", count, size);
 413 }
 414 #endif
 415
 416 void msm_gem_free_object(struct drm_gem_object *obj)
 417 {
 418         struct drm_device *dev = obj->dev;
 419         struct msm_gem_object *msm_obj = to_msm_bo(obj);
 420         int id;
 421
 422         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 423
 424         list_del(&msm_obj->mm_list);
 425
 426         for (id = 0; id < ARRAY_SIZE(msm_obj->domain); id++) {
 427                 if (msm_obj->domain[id].iova) {
 428                         struct msm_drm_private *priv = obj->dev->dev_private;
 429                         uint32_t offset = (uint32_t)mmap_offset(obj);
 430                         unmap_range(priv->iommus[id], offset,
 431                                         msm_obj->sgt, obj->size);
 432                 }
 433         }
 434
 435         drm_gem_free_mmap_offset(obj);
 436
 437         if (msm_obj->vaddr)
 438                 vunmap(msm_obj->vaddr);
 439
 440         put_pages(obj);
 441
 442         drm_gem_object_release(obj);
 443
 444         kfree(msm_obj);
 445 }
 446
 447 /* convenience method to construct a GEM buffer object, and userspace handle */
 448 int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
 449                 uint32_t size, uint32_t flags, uint32_t *handle)
 450 {
 451         struct drm_gem_object *obj;
 452         int ret;
 453
 454         ret = mutex_lock_interruptible(&dev->struct_mutex);
 455         if (ret)
 456                 return ret;
 457
 458         obj = msm_gem_new(dev, size, flags);
 459
 460         mutex_unlock(&dev->struct_mutex);
 461
 462         if (IS_ERR(obj))
 463                 return PTR_ERR(obj);
 464
 465         ret = drm_gem_handle_create(file, obj, handle);
 466
 467         /* drop reference from allocate - handle holds it now */
 468         drm_gem_object_unreference_unlocked(obj);
 469
 470         return ret;
 471 }
 472
 473 struct drm_gem_object *msm_gem_new(struct drm_device *dev,
 474                 uint32_t size, uint32_t flags)
 475 {
 476         struct msm_drm_private *priv = dev->dev_private;
 477         struct msm_gem_object *msm_obj;
 478         struct drm_gem_object *obj = NULL;
 479         int ret;
 480
 481         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 482
 483         size = PAGE_ALIGN(size);
 484
 485         switch (flags & MSM_BO_CACHE_MASK) {
 486         case MSM_BO_UNCACHED:
 487         case MSM_BO_CACHED:
 488         case MSM_BO_WC:
 489                 break;
 490         default:
 491                 dev_err(dev->dev, "invalid cache flag: %x\n",
 492                                 (flags & MSM_BO_CACHE_MASK));
 493                 ret = -EINVAL;
 494                 goto fail;
 495         }
 496
 497         msm_obj = kzalloc(sizeof(*msm_obj), GFP_KERNEL);
 498         if (!msm_obj) {
 499                 ret = -ENOMEM;
 500                 goto fail;
 501         }
 502
 503         obj = &msm_obj->base;
 504
 505         ret = drm_gem_object_init(dev, obj, size);
 506         if (ret)
 507                 goto fail;
 508
 509         msm_obj->flags = flags;
 510
 511
 512         list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
 513
 514         return obj;
 515
 516 fail:
 517         if (obj)
 518                 drm_gem_object_unreference_unlocked(obj);
 519
 520         return ERR_PTR(ret);
 521 }