drivers/gpu/drm/mediatek/mtk_drm_fb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015 MediaTek Inc.
   4  */
   5
   6 #include <drm/drmP.h>
   7 #include <drm/drm_modeset_helper.h>
   8 #include <drm/drm_fb_helper.h>
   9 #include <drm/drm_gem.h>
  10 #include <drm/drm_gem_framebuffer_helper.h>
  11 #include <linux/dma-buf.h>
  12 #include <linux/reservation.h>
  13
  14 #include "mtk_drm_drv.h"
  15 #include "mtk_drm_fb.h"
  16 #include "mtk_drm_gem.h"
  17
  18 static const struct drm_framebuffer_funcs mtk_drm_fb_funcs = {
  19         .create_handle = drm_gem_fb_create_handle,
  20         .destroy = drm_gem_fb_destroy,
  21 };
  22
  23 static struct drm_framebuffer *mtk_drm_framebuffer_init(struct drm_device *dev,
  24                                         const struct drm_mode_fb_cmd2 *mode,
  25                                         struct drm_gem_object *obj)
  26 {
  27         const struct drm_format_info *info = drm_get_format_info(dev, mode);
  28         struct drm_framebuffer *fb;
  29         int ret;
  30
  31         if (info->num_planes != 1)
  32                 return ERR_PTR(-EINVAL);
  33
  34         fb = kzalloc(sizeof(*fb), GFP_KERNEL);
  35         if (!fb)
  36                 return ERR_PTR(-ENOMEM);
  37
  38         drm_helper_mode_fill_fb_struct(dev, fb, mode);
  39
  40         fb->obj[0] = obj;
  41
  42         ret = drm_framebuffer_init(dev, fb, &mtk_drm_fb_funcs);
  43         if (ret) {
  44                 DRM_ERROR("failed to initialize framebuffer\n");
  45                 kfree(fb);
  46                 return ERR_PTR(ret);
  47         }
  48
  49         return fb;
  50 }
  51
  52 /*
  53  * Wait for any exclusive fence in fb's gem object's reservation object.
  54  *
  55  * Returns -ERESTARTSYS if interrupted, else 0.
  56  */
  57 int mtk_fb_wait(struct drm_framebuffer *fb)
  58 {
  59         struct drm_gem_object *gem;
  60         struct reservation_object *resv;
  61         long ret;
  62
  63         if (!fb)
  64                 return 0;
  65
  66         gem = fb->obj[0];
  67         if (!gem || !gem->dma_buf || !gem->dma_buf->resv)
  68                 return 0;
  69
  70         resv = gem->dma_buf->resv;
  71         ret = reservation_object_wait_timeout_rcu(resv, false, true,
  72                                                   MAX_SCHEDULE_TIMEOUT);
  73         /* MAX_SCHEDULE_TIMEOUT on success, -ERESTARTSYS if interrupted */
  74         if (WARN_ON(ret < 0))
  75                 return ret;
  76
  77         return 0;
  78 }
  79
  80 struct drm_framebuffer *mtk_drm_mode_fb_create(struct drm_device *dev,
  81                                                struct drm_file *file,
  82                                                const struct drm_mode_fb_cmd2 *cmd)
  83 {
  84         const struct drm_format_info *info = drm_get_format_info(dev, cmd);
  85         struct drm_framebuffer *fb;
  86         struct drm_gem_object *gem;
  87         unsigned int width = cmd->width;
  88         unsigned int height = cmd->height;
  89         unsigned int size, bpp;
  90         int ret;
  91
  92         if (info->num_planes != 1)
  93                 return ERR_PTR(-EINVAL);
  94
  95         gem = drm_gem_object_lookup(file, cmd->handles[0]);
  96         if (!gem)
  97                 return ERR_PTR(-ENOENT);
  98
  99         bpp = info->cpp[0];
 100         size = (height - 1) * cmd->pitches[0] + width * bpp;
 101         size += cmd->offsets[0];
 102
 103         if (gem->size < size) {
 104                 ret = -EINVAL;
 105                 goto unreference;
 106         }
 107
 108         fb = mtk_drm_framebuffer_init(dev, cmd, gem);
 109         if (IS_ERR(fb)) {
 110                 ret = PTR_ERR(fb);
 111                 goto unreference;
 112         }
 113
 114         return fb;
 115
 116 unreference:
 117         drm_gem_object_put_unlocked(gem);
 118         return ERR_PTR(ret);
 119 }