1 /* $NetBSD: i915_ioc32.c,v 1.3 2021/12/18 23:45:28 riastradh Exp $ */
2
3 /*
4 * 32-bit ioctl compatibility routines for the i915 DRM.
5 *
6 * Copyright (C) Paul Mackerras 2005
7 * Copyright (C) Alan Hourihane 2005
8 * All Rights Reserved.
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a
11 * copy of this software and associated documentation files (the "Software"),
12 * to deal in the Software without restriction, including without limitation
13 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
14 * and/or sell copies of the Software, and to permit persons to whom the
15 * Software is furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice (including the next
18 * paragraph) shall be included in all copies or substantial portions of the
19 * Software.
20 *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
24 * THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
25 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
26 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
27 * IN THE SOFTWARE.
28 *
29 * Author: Alan Hourihane <alanh@fairlite.demon.co.uk>
30 */
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: i915_ioc32.c,v 1.3 2021/12/18 23:45:28 riastradh Exp $");
33
34 #include <linux/compat.h>
35
36 #include <drm/i915_drm.h>
37 #include <drm/drm_ioctl.h>
38 #include "i915_drv.h"
39
40 struct drm_i915_getparam32 {
41 s32 param;
42 /*
43 * We screwed up the generic ioctl struct here and used a variable-sized
44 * pointer. Use u32 in the compat struct to match the 32bit pointer
45 * userspace expects.
46 */
47 u32 value;
48 };
49
compat_i915_getparam(struct file * file,unsigned int cmd,unsigned long arg)50 static int compat_i915_getparam(struct file *file, unsigned int cmd,
51 unsigned long arg)
52 {
53 struct drm_i915_getparam32 req32;
54 drm_i915_getparam_t __user *request;
55
56 if (copy_from_user(&req32, (void __user *)arg, sizeof(req32)))
57 return -EFAULT;
58
59 request = compat_alloc_user_space(sizeof(*request));
60 if (!access_ok(request, sizeof(*request)) ||
61 __put_user(req32.param, &request->param) ||
62 __put_user((void __user *)(unsigned long)req32.value,
63 &request->value))
64 return -EFAULT;
65
66 return drm_ioctl(file, DRM_IOCTL_I915_GETPARAM,
67 (unsigned long)request);
68 }
69
70 static drm_ioctl_compat_t *i915_compat_ioctls[] = {
71 [DRM_I915_GETPARAM] = compat_i915_getparam,
72 };
73
74 /**
75 * i915_compat_ioctl - handle the mistakes of the past
76 * @filp: the file pointer
77 * @cmd: the ioctl command (and encoded flags)
78 * @arg: the ioctl argument (from userspace)
79 *
80 * Called whenever a 32-bit process running under a 64-bit kernel
81 * performs an ioctl on /dev/dri/card<n>.
82 */
i915_compat_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)83 long i915_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
84 {
85 unsigned int nr = DRM_IOCTL_NR(cmd);
86 drm_ioctl_compat_t *fn = NULL;
87 int ret;
88
89 if (nr < DRM_COMMAND_BASE || nr >= DRM_COMMAND_END)
90 return drm_compat_ioctl(filp, cmd, arg);
91
92 if (nr < DRM_COMMAND_BASE + ARRAY_SIZE(i915_compat_ioctls))
93 fn = i915_compat_ioctls[nr - DRM_COMMAND_BASE];
94
95 if (fn != NULL)
96 ret = (*fn) (filp, cmd, arg);
97 else
98 ret = drm_ioctl(filp, cmd, arg);
99
100 return ret;
101 }
102