drivers/gpu/drm/msm/msm_ringbuffer.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 "msm_ringbuffer.h"
  19 #include "msm_gpu.h"
  20
  21 struct msm_ringbuffer *msm_ringbuffer_new(struct msm_gpu *gpu, int size)
  22 {
  23         struct msm_ringbuffer *ring;
  24         int ret;
  25
  26         if (WARN_ON(!is_power_of_2(size)))
  27                 return ERR_PTR(-EINVAL);
  28
  29         ring = kzalloc(sizeof(*ring), GFP_KERNEL);
  30         if (!ring) {
  31                 ret = -ENOMEM;
  32                 goto fail;
  33         }
  34
  35         ring->gpu = gpu;
  36         ring->bo = msm_gem_new(gpu->dev, size, MSM_BO_WC);
  37         if (IS_ERR(ring->bo)) {
  38                 ret = PTR_ERR(ring->bo);
  39                 ring->bo = NULL;
  40                 goto fail;
  41         }
  42
  43         ring->start = msm_gem_vaddr_locked(ring->bo);
  44         ring->end   = ring->start + (size / 4);
  45         ring->cur   = ring->start;
  46
  47         ring->size = size;
  48
  49         return ring;
  50
  51 fail:
  52         if (ring)
  53                 msm_ringbuffer_destroy(ring);
  54         return ERR_PTR(ret);
  55 }
  56
  57 void msm_ringbuffer_destroy(struct msm_ringbuffer *ring)
  58 {
  59         if (ring->bo)
  60                 drm_gem_object_unreference_unlocked(ring->bo);
  61         kfree(ring);
  62 }