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/drm_ioctl.h>
  32
  33#include "i915_drv.h"
  34#include "i915_ioc32.h"
  35
  36struct 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
  46static 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
  62static 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 */
  75long 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}
  94