LXR linux/drivers/gpu/drm/i915/i915

   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/i915_drm.h>
  32#include <drm/drm_ioctl.h>
  33#include "i915_drv.h"
  34
  35struct drm_i915_getparam32 {
  36        s32 param;
  37        /*
  38         * We screwed up the generic ioctl struct here and used a variable-sized
  39         * pointer. Use u32 in the compat struct to match the 32bit pointer
  40         * userspace expects.
  41         */
  42        u32 value;
  43};
  44
  45static int compat_i915_getparam(struct file *file, unsigned int cmd,
  46                                unsigned long arg)
  47{
  48        struct drm_i915_getparam32 req32;
  49        drm_i915_getparam_t __user *request;
  50
  51        if (copy_from_user(&req32, (void __user *)arg, sizeof(req32)))
  52                return -EFAULT;
  53
  54        request = compat_alloc_user_space(sizeof(*request));
  55        if (!access_ok(request, sizeof(*request)) ||
  56            __put_user(req32.param, &request->param) ||
  57            __put_user((void __user *)(unsigned long)req32.value,
  58                       &request->value))
  59                return -EFAULT;
  60
  61        return drm_ioctl(file, DRM_IOCTL_I915_GETPARAM,
  62                         (unsigned long)request);
  63}
  64
  65static drm_ioctl_compat_t *i915_compat_ioctls[] = {
  66        [DRM_I915_GETPARAM] = compat_i915_getparam,
  67};
  68
  69/**
  70 * i915_compat_ioctl - handle the mistakes of the past
  71 * @filp: the file pointer
  72 * @cmd: the ioctl command (and encoded flags)
  73 * @arg: the ioctl argument (from userspace)
  74 *
  75 * Called whenever a 32-bit process running under a 64-bit kernel
  76 * performs an ioctl on /dev/dri/card<n>.
  77 */
  78long i915_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  79{
  80        unsigned int nr = DRM_IOCTL_NR(cmd);
  81        drm_ioctl_compat_t *fn = NULL;
  82        int ret;
  83
  84        if (nr < DRM_COMMAND_BASE || nr >= DRM_COMMAND_END)
  85                return drm_compat_ioctl(filp, cmd, arg);
  86
  87        if (nr < DRM_COMMAND_BASE + ARRAY_SIZE(i915_compat_ioctls))
  88                fn = i915_compat_ioctls[nr - DRM_COMMAND_BASE];
  89
  90        if (fn != NULL)
  91                ret = (*fn) (filp, cmd, arg);
  92        else
  93                ret = drm_ioctl(filp, cmd, arg);
  94
  95        return ret;
  96}
  97