drivers/gpu/drm/v3d/v3d_bo.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /* Copyright (C) 2015-2018 Broadcom */
   3
   4 /**
   5  * DOC: V3D GEM BO management support
   6  *
   7  * Compared to VC4 (V3D 2.x), V3D 3.3 introduces an MMU between the
   8  * GPU and the bus, allowing us to use shmem objects for our storage
   9  * instead of CMA.
  10  *
  11  * Physically contiguous objects may still be imported to V3D, but the
  12  * driver doesn't allocate physically contiguous objects on its own.
  13  * Display engines requiring physically contiguous allocations should
  14  * look into Mesa's "renderonly" support (as used by the Mesa pl111
  15  * driver) for an example of how to integrate with V3D.
  16  *
  17  * Long term, we should support evicting pages from the MMU when under
  18  * memory pressure (thus the v3d_bo_get_pages() refcounting), but
  19  * that's not a high priority since our systems tend to not have swap.
  20  */
  21
  22 #include <linux/dma-buf.h>
  23 #include <linux/pfn_t.h>
  24
  25 #include "v3d_drv.h"
  26 #include "uapi/drm/v3d_drm.h"
  27
  28 /* Called DRM core on the last userspace/kernel unreference of the
  29  * BO.
  30  */
  31 void v3d_free_object(struct drm_gem_object *obj)
  32 {
  33         struct v3d_dev *v3d = to_v3d_dev(obj->dev);
  34         struct v3d_bo *bo = to_v3d_bo(obj);
  35
  36         v3d_mmu_remove_ptes(bo);
  37
  38         mutex_lock(&v3d->bo_lock);
  39         v3d->bo_stats.num_allocated--;
  40         v3d->bo_stats.pages_allocated -= obj->size >> PAGE_SHIFT;
  41         mutex_unlock(&v3d->bo_lock);
  42
  43         spin_lock(&v3d->mm_lock);
  44         drm_mm_remove_node(&bo->node);
  45         spin_unlock(&v3d->mm_lock);
  46
  47         /* GPU execution may have dirtied any pages in the BO. */
  48         bo->base.pages_mark_dirty_on_put = true;
  49
  50         drm_gem_shmem_free_object(obj);
  51 }
  52
  53 static const struct drm_gem_object_funcs v3d_gem_funcs = {
  54         .free = v3d_free_object,
  55         .print_info = drm_gem_shmem_print_info,
  56         .pin = drm_gem_shmem_pin,
  57         .unpin = drm_gem_shmem_unpin,
  58         .get_sg_table = drm_gem_shmem_get_sg_table,
  59         .vmap = drm_gem_shmem_vmap,
  60         .vunmap = drm_gem_shmem_vunmap,
  61         .mmap = drm_gem_shmem_mmap,
  62 };
  63
  64 /* gem_create_object function for allocating a BO struct and doing
  65  * early setup.
  66  */
  67 struct drm_gem_object *v3d_create_object(struct drm_device *dev, size_t size)
  68 {
  69         struct v3d_bo *bo;
  70         struct drm_gem_object *obj;
  71
  72         if (size == 0)
  73                 return NULL;
  74
  75         bo = kzalloc(sizeof(*bo), GFP_KERNEL);
  76         if (!bo)
  77                 return NULL;
  78         obj = &bo->base.base;
  79
  80         obj->funcs = &v3d_gem_funcs;
  81
  82         INIT_LIST_HEAD(&bo->unref_head);
  83
  84         return &bo->base.base;
  85 }
  86
  87 static int
  88 v3d_bo_create_finish(struct drm_gem_object *obj)
  89 {
  90         struct v3d_dev *v3d = to_v3d_dev(obj->dev);
  91         struct v3d_bo *bo = to_v3d_bo(obj);
  92         struct sg_table *sgt;
  93         int ret;
  94
  95         /* So far we pin the BO in the MMU for its lifetime, so use
  96          * shmem's helper for getting a lifetime sgt.
  97          */
  98         sgt = drm_gem_shmem_get_pages_sgt(&bo->base.base);
  99         if (IS_ERR(sgt))
 100                 return PTR_ERR(sgt);
 101
 102         spin_lock(&v3d->mm_lock);
 103         /* Allocate the object's space in the GPU's page tables.
 104          * Inserting PTEs will happen later, but the offset is for the
 105          * lifetime of the BO.
 106          */
 107         ret = drm_mm_insert_node_generic(&v3d->mm, &bo->node,
 108                                          obj->size >> PAGE_SHIFT,
 109                                          GMP_GRANULARITY >> PAGE_SHIFT, 0, 0);
 110         spin_unlock(&v3d->mm_lock);
 111         if (ret)
 112                 return ret;
 113
 114         /* Track stats for /debug/dri/n/bo_stats. */
 115         mutex_lock(&v3d->bo_lock);
 116         v3d->bo_stats.num_allocated++;
 117         v3d->bo_stats.pages_allocated += obj->size >> PAGE_SHIFT;
 118         mutex_unlock(&v3d->bo_lock);
 119
 120         v3d_mmu_insert_ptes(bo);
 121
 122         return 0;
 123 }
 124
 125 struct v3d_bo *v3d_bo_create(struct drm_device *dev, struct drm_file *file_priv,
 126                              size_t unaligned_size)
 127 {
 128         struct drm_gem_shmem_object *shmem_obj;
 129         struct v3d_bo *bo;
 130         int ret;
 131
 132         shmem_obj = drm_gem_shmem_create(dev, unaligned_size);
 133         if (IS_ERR(shmem_obj))
 134                 return ERR_CAST(shmem_obj);
 135         bo = to_v3d_bo(&shmem_obj->base);
 136
 137         ret = v3d_bo_create_finish(&shmem_obj->base);
 138         if (ret)
 139                 goto free_obj;
 140
 141         return bo;
 142
 143 free_obj:
 144         drm_gem_shmem_free_object(&shmem_obj->base);
 145         return ERR_PTR(ret);
 146 }
 147
 148 struct drm_gem_object *
 149 v3d_prime_import_sg_table(struct drm_device *dev,
 150                           struct dma_buf_attachment *attach,
 151                           struct sg_table *sgt)
 152 {
 153         struct drm_gem_object *obj;
 154         int ret;
 155
 156         obj = drm_gem_shmem_prime_import_sg_table(dev, attach, sgt);
 157         if (IS_ERR(obj))
 158                 return obj;
 159
 160         ret = v3d_bo_create_finish(obj);
 161         if (ret) {
 162                 drm_gem_shmem_free_object(obj);
 163                 return ERR_PTR(ret);
 164         }
 165
 166         return obj;
 167 }
 168
 169 static void v3d_gem_register_pid(struct drm_file *file)
 170 {
 171         struct v3d_file_priv *v3d_priv = file->driver_priv;
 172         struct drm_v3d_file_private *pid_priv;
 173
 174         if (!v3d_priv)
 175                 return;
 176
 177         pid_priv = &v3d_priv->priv;
 178
 179         if (!pid_priv->pid && !pid_priv->tgid) {
 180                 pid_priv->pid = task_pid_nr(current);
 181                 pid_priv->tgid = task_tgid_nr(current);
 182         } else {
 183                 if (pid_priv->pid != task_pid_nr(current))
 184                         DRM_DEBUG_KMS("wrong pid: %ld, %ld\n",
 185                                         (unsigned long)pid_priv->pid,
 186                                         (unsigned long)task_pid_nr(current));
 187                 if (pid_priv->tgid != task_tgid_nr(current))
 188                         DRM_DEBUG_KMS("wrong tgid: %ld, %ld\n",
 189                                         (unsigned long)pid_priv->tgid,
 190                                         (unsigned long)task_tgid_nr(current));
 191         }
 192 }
 193
 194 int v3d_drm_gem_prime_fd_to_handle(struct drm_device *dev,
 195                                    struct drm_file *file_priv, int prime_fd,
 196                                    uint32_t *handle)
 197 {
 198         int ret;
 199
 200         ret = drm_gem_prime_fd_to_handle(dev, file_priv, prime_fd, handle);
 201         if (ret < 0)
 202                 return ret;
 203
 204         v3d_gem_register_pid(file_priv);
 205
 206         return ret;
 207 }
 208
 209 int v3d_create_bo_ioctl(struct drm_device *dev, void *data,
 210                         struct drm_file *file_priv)
 211 {
 212         struct drm_v3d_create_bo *args = data;
 213         struct v3d_bo *bo = NULL;
 214         int ret;
 215
 216         if (args->flags != 0) {
 217                 DRM_INFO("unknown create_bo flags: %d\n", args->flags);
 218                 return -EINVAL;
 219         }
 220
 221         bo = v3d_bo_create(dev, file_priv, PAGE_ALIGN(args->size));
 222         if (IS_ERR(bo))
 223                 return PTR_ERR(bo);
 224
 225         args->offset = bo->node.start << PAGE_SHIFT;
 226
 227         ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
 228         if (!ret)
 229                 v3d_gem_register_pid(file_priv);
 230
 231         drm_gem_object_put(&bo->base.base);
 232
 233         return ret;
 234 }
 235
 236 int v3d_mmap_bo_ioctl(struct drm_device *dev, void *data,
 237                       struct drm_file *file_priv)
 238 {
 239         struct drm_v3d_mmap_bo *args = data;
 240         struct drm_gem_object *gem_obj;
 241
 242         if (args->flags != 0) {
 243                 DRM_INFO("unknown mmap_bo flags: %d\n", args->flags);
 244                 return -EINVAL;
 245         }
 246
 247         gem_obj = drm_gem_object_lookup(file_priv, args->handle);
 248         if (!gem_obj) {
 249                 DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
 250                 return -ENOENT;
 251         }
 252
 253         args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
 254         drm_gem_object_put(gem_obj);
 255
 256         return 0;
 257 }
 258
 259 int v3d_get_bo_offset_ioctl(struct drm_device *dev, void *data,
 260                             struct drm_file *file_priv)
 261 {
 262         struct drm_v3d_get_bo_offset *args = data;
 263         struct drm_gem_object *gem_obj;
 264         struct v3d_bo *bo;
 265
 266         gem_obj = drm_gem_object_lookup(file_priv, args->handle);
 267         if (!gem_obj) {
 268                 DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
 269                 return -ENOENT;
 270         }
 271         bo = to_v3d_bo(gem_obj);
 272
 273         args->offset = bo->node.start << PAGE_SHIFT;
 274
 275         drm_gem_object_put(gem_obj);
 276         return 0;
 277 }