drivers/gpu/drm/i915/i915_ioc32.c

   1 /*
   2  * 32-bit ioctl compatibility routines for the i915 DRM.
   3  *
   4  * Copyright (C) Paul Mackerras 2005
   5  * Copyright (C) Alan Hourihane 2005
   6  * All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the next
  16  * paragraph) shall be included in all copies or substantial portions of the
  17  * Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  23  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  25  * IN THE SOFTWARE.
  26  *
  27  * Author: Alan Hourihane <alanh@fairlite.demon.co.uk>
  28  */
  29 #include <linux/compat.h>
  30
  31 #include <drm/drm_ioctl.h>
  32
  33 #include "i915_drv.h"
  34 #include "i915_ioc32.h"
  35
  36 struct drm_i915_getparam32 {
  37         s32 param;
  38         /*
  39          * We screwed up the generic ioctl struct here and used a variable-sized
  40          * pointer. Use u32 in the compat struct to match the 32bit pointer
  41          * userspace expects.
  42          */
  43         u32 value;
  44 };
  45
  46 static int compat_i915_getparam(struct file *file, unsigned int cmd,
  47                                 unsigned long arg)
  48 {
  49         struct drm_i915_getparam32 req32;
  50         struct drm_i915_getparam req;
  51
  52         if (copy_from_user(&req32, (void __user *)arg, sizeof(req32)))
  53                 return -EFAULT;
  54
  55         req.param = req32.param;
  56         req.value = compat_ptr(req32.value);
  57
  58         return drm_ioctl_kernel(file, i915_getparam_ioctl, &req,
  59                                 DRM_RENDER_ALLOW);
  60 }
  61
  62 static drm_ioctl_compat_t *i915_compat_ioctls[] = {
  63         [DRM_I915_GETPARAM] = compat_i915_getparam,
  64 };
  65
  66 /**
  67  * i915_ioc32_compat_ioctl - handle the mistakes of the past
  68  * @filp: the file pointer
  69  * @cmd: the ioctl command (and encoded flags)
  70  * @arg: the ioctl argument (from userspace)
  71  *
  72  * Called whenever a 32-bit process running under a 64-bit kernel
  73  * performs an ioctl on /dev/dri/card<n>.
  74  */
  75 long i915_ioc32_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  76 {
  77         unsigned int nr = DRM_IOCTL_NR(cmd);
  78         drm_ioctl_compat_t *fn = NULL;
  79         int ret;
  80
  81         if (nr < DRM_COMMAND_BASE || nr >= DRM_COMMAND_END)
  82                 return drm_compat_ioctl(filp, cmd, arg);
  83
  84         if (nr < DRM_COMMAND_BASE + ARRAY_SIZE(i915_compat_ioctls))
  85                 fn = i915_compat_ioctls[nr - DRM_COMMAND_BASE];
  86
  87         if (fn != NULL)
  88                 ret = (*fn) (filp, cmd, arg);
  89         else
  90                 ret = drm_ioctl(filp, cmd, arg);
  91
  92         return ret;
  93 }