drivers/gpu/drm/i915/i915_query.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright © 2018 Intel Corporation
   5  */
   6
   7 #include <linux/nospec.h>
   8
   9 #include "i915_drv.h"
  10 #include "i915_query.h"
  11 #include <uapi/drm/i915_drm.h>
  12
  13 static int query_topology_info(struct drm_i915_private *dev_priv,
  14                                struct drm_i915_query_item *query_item)
  15 {
  16         const struct sseu_dev_info *sseu = &INTEL_INFO(dev_priv)->sseu;
  17         struct drm_i915_query_topology_info topo;
  18         u32 slice_length, subslice_length, eu_length, total_length;
  19
  20         if (query_item->flags != 0)
  21                 return -EINVAL;
  22
  23         if (sseu->max_slices == 0)
  24                 return -ENODEV;
  25
  26         BUILD_BUG_ON(sizeof(u8) != sizeof(sseu->slice_mask));
  27
  28         slice_length = sizeof(sseu->slice_mask);
  29         subslice_length = sseu->max_slices *
  30                 DIV_ROUND_UP(sseu->max_subslices, BITS_PER_BYTE);
  31         eu_length = sseu->max_slices * sseu->max_subslices *
  32                 DIV_ROUND_UP(sseu->max_eus_per_subslice, BITS_PER_BYTE);
  33
  34         total_length = sizeof(topo) + slice_length + subslice_length + eu_length;
  35
  36         if (query_item->length == 0)
  37                 return total_length;
  38
  39         if (query_item->length < total_length)
  40                 return -EINVAL;
  41
  42         if (copy_from_user(&topo, u64_to_user_ptr(query_item->data_ptr),
  43                            sizeof(topo)))
  44                 return -EFAULT;
  45
  46         if (topo.flags != 0)
  47                 return -EINVAL;
  48
  49         if (!access_ok(VERIFY_WRITE, u64_to_user_ptr(query_item->data_ptr),
  50                        total_length))
  51                 return -EFAULT;
  52
  53         memset(&topo, 0, sizeof(topo));
  54         topo.max_slices = sseu->max_slices;
  55         topo.max_subslices = sseu->max_subslices;
  56         topo.max_eus_per_subslice = sseu->max_eus_per_subslice;
  57
  58         topo.subslice_offset = slice_length;
  59         topo.subslice_stride = DIV_ROUND_UP(sseu->max_subslices, BITS_PER_BYTE);
  60         topo.eu_offset = slice_length + subslice_length;
  61         topo.eu_stride =
  62                 DIV_ROUND_UP(sseu->max_eus_per_subslice, BITS_PER_BYTE);
  63
  64         if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr),
  65                            &topo, sizeof(topo)))
  66                 return -EFAULT;
  67
  68         if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr + sizeof(topo)),
  69                            &sseu->slice_mask, slice_length))
  70                 return -EFAULT;
  71
  72         if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr +
  73                                            sizeof(topo) + slice_length),
  74                            sseu->subslice_mask, subslice_length))
  75                 return -EFAULT;
  76
  77         if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr +
  78                                            sizeof(topo) +
  79                                            slice_length + subslice_length),
  80                            sseu->eu_mask, eu_length))
  81                 return -EFAULT;
  82
  83         return total_length;
  84 }
  85
  86 static int (* const i915_query_funcs[])(struct drm_i915_private *dev_priv,
  87                                         struct drm_i915_query_item *query_item) = {
  88         query_topology_info,
  89 };
  90
  91 int i915_query_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
  92 {
  93         struct drm_i915_private *dev_priv = to_i915(dev);
  94         struct drm_i915_query *args = data;
  95         struct drm_i915_query_item __user *user_item_ptr =
  96                 u64_to_user_ptr(args->items_ptr);
  97         u32 i;
  98
  99         if (args->flags != 0)
 100                 return -EINVAL;
 101
 102         for (i = 0; i < args->num_items; i++, user_item_ptr++) {
 103                 struct drm_i915_query_item item;
 104                 unsigned long func_idx;
 105                 int ret;
 106
 107                 if (copy_from_user(&item, user_item_ptr, sizeof(item)))
 108                         return -EFAULT;
 109
 110                 if (item.query_id == 0)
 111                         return -EINVAL;
 112
 113                 if (overflows_type(item.query_id - 1, unsigned long))
 114                         return -EINVAL;
 115
 116                 func_idx = item.query_id - 1;
 117
 118                 ret = -EINVAL;
 119                 if (func_idx < ARRAY_SIZE(i915_query_funcs)) {
 120                         func_idx = array_index_nospec(func_idx,
 121                                                       ARRAY_SIZE(i915_query_funcs));
 122                         ret = i915_query_funcs[func_idx](dev_priv, &item);
 123                 }
 124
 125                 /* Only write the length back to userspace if they differ. */
 126                 if (ret != item.length && put_user(ret, &user_item_ptr->length))
 127                         return -EFAULT;
 128         }
 129
 130         return 0;
 131 }