drm: 32/64-bit DRM ioctl compatibility patch

The patch is against a 2.6.11 kernel tree.  I am running this with a
32-bit X server (compiled up from X.org CVS as of a couple of weeks
ago) and 32-bit DRI libraries and clients.  All the userland stuff is
identical to what I am using under a 32-bit kernel on my G4 powerbook
(which is a 32-bit machine of course).  I haven't tried compiling up a
64-bit X server or clients yet.

In the compatibility routines I have assumed that the kernel can
safely access user addresses after set_fs(KERNEL_DS).  That is, where
an ioctl argument structure contains pointers to other structures, and
those other structures are already compatible between the 32-bit and
64-bit ABIs (i.e. they only contain things like chars, shorts or
ints), I just check the address with access_ok() and then pass it
through to the 64-bit ioctl code.  I believe this approach may not
work on sparc64, but it does work on ppc64 and x86_64 at least.

One tricky area which may need to be revisited is the question of how
to handle the handles which we pass back to userspace to identify
mappings.  These handles are generated in the ADDMAP ioctl and then
passed in as the offset value to mmap.  However, offset values for
mmap seem to be generated in other ways as well, particularly for AGP
mappings.

The approach I have ended up with is to generate a fake 32-bit handle
only for _DRM_SHM mappings.  The handles for other mappings (AGP, REG,
FB) are physical addresses which are already limited to 32 bits, and
generating fake handles for them created all sorts of problems in the
mmap/nopage code.

This patch has been updated to use the new compatibility ioctls.

From: Paul Mackerras <paulus@samba.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>

1 files changed, 1069 insertions, 0 deletions

diff --git a/drivers/char/drm/drm_ioc32.c b/drivers/char/drm/drm_ioc32.c
new file mode 100644
index 000000000000..8087a9636399
--- /dev/null
+++ b/drivers/char/drm/drm_ioc32.c
@@ -0,0 +1,1069 @@
+/**
+ * \file drm_ioc32.c
+ *
+ * 32-bit ioctl compatibility routines for the DRM.
+ *
+ * \author Paul Mackerras <paulus@samba.org>
+ *
+ * Copyright (C) Paul Mackerras 2005.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+#include <linux/compat.h>
+#include <linux/ioctl32.h>
+
+#include "drmP.h"
+#include "drm_core.h"
+
+#define DRM_IOCTL_VERSION32             DRM_IOWR(0x00, drm_version32_t)
+#define DRM_IOCTL_GET_UNIQUE32          DRM_IOWR(0x01, drm_unique32_t)
+#define DRM_IOCTL_GET_MAP32             DRM_IOWR(0x04, drm_map32_t)
+#define DRM_IOCTL_GET_CLIENT32          DRM_IOWR(0x05, drm_client32_t)
+#define DRM_IOCTL_GET_STATS32           DRM_IOR( 0x06, drm_stats32_t)
+
+#define DRM_IOCTL_SET_UNIQUE32          DRM_IOW( 0x10, drm_unique32_t)
+#define DRM_IOCTL_ADD_MAP32             DRM_IOWR(0x15, drm_map32_t)
+#define DRM_IOCTL_ADD_BUFS32            DRM_IOWR(0x16, drm_buf_desc32_t)
+#define DRM_IOCTL_MARK_BUFS32           DRM_IOW( 0x17, drm_buf_desc32_t)
+#define DRM_IOCTL_INFO_BUFS32           DRM_IOWR(0x18, drm_buf_info32_t)
+#define DRM_IOCTL_MAP_BUFS32            DRM_IOWR(0x19, drm_buf_map32_t)
+#define DRM_IOCTL_FREE_BUFS32           DRM_IOW( 0x1a, drm_buf_free32_t)
+
+#define DRM_IOCTL_RM_MAP32              DRM_IOW( 0x1b, drm_map32_t)
+
+#define DRM_IOCTL_SET_SAREA_CTX32       DRM_IOW( 0x1c, drm_ctx_priv_map32_t)
+#define DRM_IOCTL_GET_SAREA_CTX32       DRM_IOWR(0x1d, drm_ctx_priv_map32_t)
+
+#define DRM_IOCTL_RES_CTX32             DRM_IOWR(0x26, drm_ctx_res32_t)
+#define DRM_IOCTL_DMA32                 DRM_IOWR(0x29, drm_dma32_t)
+
+#define DRM_IOCTL_AGP_ENABLE32          DRM_IOW( 0x32, drm_agp_mode32_t)
+#define DRM_IOCTL_AGP_INFO32            DRM_IOR( 0x33, drm_agp_info32_t)
+#define DRM_IOCTL_AGP_ALLOC32           DRM_IOWR(0x34, drm_agp_buffer32_t)
+#define DRM_IOCTL_AGP_FREE32            DRM_IOW( 0x35, drm_agp_buffer32_t)
+#define DRM_IOCTL_AGP_BIND32            DRM_IOW( 0x36, drm_agp_binding32_t)
+#define DRM_IOCTL_AGP_UNBIND32          DRM_IOW( 0x37, drm_agp_binding32_t)
+
+#define DRM_IOCTL_SG_ALLOC32            DRM_IOW( 0x38, drm_scatter_gather32_t)
+#define DRM_IOCTL_SG_FREE32             DRM_IOW( 0x39, drm_scatter_gather32_t)
+
+#define DRM_IOCTL_WAIT_VBLANK32         DRM_IOWR(0x3a, drm_wait_vblank32_t)
+
+typedef struct drm_version_32 {
+        int     version_major;    /**< Major version */
+        int     version_minor;    /**< Minor version */
+        int     version_patchlevel;/**< Patch level */
+        u32     name_len;         /**< Length of name buffer */
+        u32     name;             /**< Name of driver */
+        u32     date_len;         /**< Length of date buffer */
+        u32     date;             /**< User-space buffer to hold date */
+        u32     desc_len;         /**< Length of desc buffer */
+        u32     desc;             /**< User-space buffer to hold desc */
+} drm_version32_t;
+
+static int compat_drm_version(struct file *file, unsigned int cmd,
+                              unsigned long arg)
+{
+        drm_version32_t v32;
+        drm_version_t __user *version;
+        int err;
+
+        if (copy_from_user(&v32, (void __user *) arg, sizeof(v32)))
+                return -EFAULT;
+
+        version = compat_alloc_user_space(sizeof(*version));
+        if (!access_ok(VERIFY_WRITE, version, sizeof(*version)))
+                return -EFAULT;
+        if (__put_user(v32.name_len, &version->name_len)
+            || __put_user((void __user *)(unsigned long)v32.name,
+                          &version->name)
+            || __put_user(v32.date_len, &version->date_len)
+            || __put_user((void __user *)(unsigned long)v32.date,
+                          &version->date)
+            || __put_user(v32.desc_len, &version->desc_len)
+            || __put_user((void __user *)(unsigned long)v32.desc,
+                          &version->desc))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_VERSION, (unsigned long) version);
+        if (err)
+                return err;
+
+        if (__get_user(v32.version_major, &version->version_major)
+            || __get_user(v32.version_minor, &version->version_minor)
+            || __get_user(v32.version_patchlevel, &version->version_patchlevel)
+            || __get_user(v32.name_len, &version->name_len)
+            || __get_user(v32.date_len, &version->date_len)
+            || __get_user(v32.desc_len, &version->desc_len))
+                return -EFAULT;
+
+        if (copy_to_user((void __user *) arg, &v32, sizeof(v32)))
+                return -EFAULT;
+        return 0;
+}
+
+typedef struct drm_unique32 {
+        u32 unique_len; /**< Length of unique */
+        u32 unique;     /**< Unique name for driver instantiation */
+} drm_unique32_t;
+
+static int compat_drm_getunique(struct file *file, unsigned int cmd,
+                                unsigned long arg)
+{
+        drm_unique32_t uq32;
+        drm_unique_t __user *u;
+        int err;
+
+        if (copy_from_user(&uq32, (void __user *) arg, sizeof(uq32)))
+                return -EFAULT;
+
+        u = compat_alloc_user_space(sizeof(*u));
+        if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
+                return -EFAULT;
+        if (__put_user(uq32.unique_len, &u->unique_len)
+            || __put_user((void __user *)(unsigned long) uq32.unique,
+                          &u->unique))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_GET_UNIQUE, (unsigned long) u);
+        if (err)
+                return err;
+
+        if (__get_user(uq32.unique_len, &u->unique_len))
+                return -EFAULT;
+        if (copy_to_user((void __user *) arg, &uq32, sizeof(uq32)))
+                return -EFAULT;
+        return 0;
+}
+
+static int compat_drm_setunique(struct file *file, unsigned int cmd,
+                                unsigned long arg)
+{
+        drm_unique32_t uq32;
+        drm_unique_t __user *u;
+
+        if (copy_from_user(&uq32, (void __user *) arg, sizeof(uq32)))
+                return -EFAULT;
+
+        u = compat_alloc_user_space(sizeof(*u));
+        if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
+                return -EFAULT;
+        if (__put_user(uq32.unique_len, &u->unique_len)
+            || __put_user((void __user *)(unsigned long) uq32.unique,
+                          &u->unique))
+                return -EFAULT;
+
+        return drm_ioctl(file->f_dentry->d_inode, file,
+                         DRM_IOCTL_SET_UNIQUE, (unsigned long) u);
+}
+
+typedef struct drm_map32 {
+        u32     offset;         /**< Requested physical address (0 for SAREA)*/
+        u32     size;           /**< Requested physical size (bytes) */
+        drm_map_type_t  type;   /**< Type of memory to map */
+        drm_map_flags_t flags;  /**< Flags */
+        u32     handle;         /**< User-space: "Handle" to pass to mmap() */
+        int     mtrr;           /**< MTRR slot used */
+} drm_map32_t;
+
+static int compat_drm_getmap(struct file *file, unsigned int cmd,
+                             unsigned long arg)
+{
+        drm_map32_t __user *argp = (void __user *)arg;
+        drm_map32_t m32;
+        drm_map_t __user *map;
+        int idx, err;
+        void *handle;
+
+        if (get_user(idx, &argp->offset))
+                return -EFAULT;
+
+        map = compat_alloc_user_space(sizeof(*map));
+        if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
+                return -EFAULT;
+        if (__put_user(idx, &map->offset))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_GET_MAP, (unsigned long) map);
+        if (err)
+                return err;
+
+        if (__get_user(m32.offset, &map->offset)
+            || __get_user(m32.size, &map->size)
+            || __get_user(m32.type, &map->type)
+            || __get_user(m32.flags, &map->flags)
+            || __get_user(handle, &map->handle)
+            || __get_user(m32.mtrr, &map->mtrr))
+                return -EFAULT;
+
+        m32.handle = (unsigned long) handle;
+        if (copy_to_user(argp, &m32, sizeof(m32)))
+                return -EFAULT;
+        return 0;
+
+}
+
+static int compat_drm_addmap(struct file *file, unsigned int cmd,
+                             unsigned long arg)
+{
+        drm_map32_t __user *argp = (void __user *)arg;
+        drm_map32_t m32;
+        drm_map_t __user *map;
+        int err;
+        void *handle;
+
+        if (copy_from_user(&m32, argp, sizeof(m32)))
+                return -EFAULT;
+
+        map = compat_alloc_user_space(sizeof(*map));
+        if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
+                return -EFAULT;
+        if (__put_user(m32.offset, &map->offset)
+            || __put_user(m32.size, &map->size)
+            || __put_user(m32.type, &map->type)
+            || __put_user(m32.flags, &map->flags))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_ADD_MAP, (unsigned long) map);
+        if (err)
+                return err;
+
+        if (__get_user(m32.offset, &map->offset)
+            || __get_user(m32.mtrr, &map->mtrr)
+            || __get_user(handle, &map->handle))
+                return -EFAULT;
+
+        m32.handle = (unsigned long) handle;
+        if (m32.handle != (unsigned long) handle && printk_ratelimit())
+                printk(KERN_ERR "compat_drm_addmap truncated handle"
+                       " %p for type %d offset %x\n",
+                       handle, m32.type, m32.offset);
+
+        if (copy_to_user(argp, &m32, sizeof(m32)))
+                return -EFAULT;
+
+        return 0;
+}
+
+static int compat_drm_rmmap(struct file *file, unsigned int cmd,
+                            unsigned long arg)
+{
+        drm_map32_t __user *argp = (void __user *)arg;
+        drm_map_t __user *map;
+        u32 handle;
+
+        if (get_user(handle, &argp->handle))
+                return -EFAULT;
+
+        map = compat_alloc_user_space(sizeof(*map));
+        if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
+                return -EFAULT;
+        if (__put_user((void *)(unsigned long) handle, &map->handle))
+                return -EFAULT;
+
+        return drm_ioctl(file->f_dentry->d_inode, file,
+                         DRM_IOCTL_RM_MAP, (unsigned long) map);
+}
+
+typedef struct drm_client32 {
+        int     idx;    /**< Which client desired? */
+        int     auth;   /**< Is client authenticated? */
+        u32     pid;    /**< Process ID */
+        u32     uid;    /**< User ID */
+        u32     magic;  /**< Magic */
+        u32     iocs;   /**< Ioctl count */
+} drm_client32_t;
+
+static int compat_drm_getclient(struct file *file, unsigned int cmd,
+                                unsigned long arg)
+{
+        drm_client32_t c32;
+        drm_client32_t __user *argp = (void __user *)arg;
+        drm_client_t __user *client;
+        int idx, err;
+
+        if (get_user(idx, &argp->idx))
+                return -EFAULT;
+
+        client = compat_alloc_user_space(sizeof(*client));
+        if (!access_ok(VERIFY_WRITE, client, sizeof(*client)))
+                return -EFAULT;
+        if (__put_user(idx, &client->idx))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_GET_CLIENT, (unsigned long) client);
+        if (err)
+                return err;
+
+        if (__get_user(c32.auth, &client->auth)
+            || __get_user(c32.pid, &client->pid)
+            || __get_user(c32.uid, &client->uid)
+            || __get_user(c32.magic, &client->magic)
+            || __get_user(c32.iocs, &client->iocs))
+                return -EFAULT;
+
+        if (copy_to_user(argp, &c32, sizeof(c32)))
+                return -EFAULT;
+        return 0;
+}
+
+typedef struct drm_stats32 {
+        u32 count;
+        struct {
+                u32 value;
+                drm_stat_type_t type;
+        } data[15];
+} drm_stats32_t;
+
+static int compat_drm_getstats(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+        drm_stats32_t s32;
+        drm_stats32_t __user *argp = (void __user *)arg;
+        drm_stats_t __user *stats;
+        int i, err;
+
+        stats = compat_alloc_user_space(sizeof(*stats));
+        if (!access_ok(VERIFY_WRITE, stats, sizeof(*stats)))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_GET_STATS, (unsigned long) stats);
+        if (err)
+                return err;
+
+        if (__get_user(s32.count, &stats->count))
+                return -EFAULT;
+        for (i = 0; i < 15; ++i)
+                if (__get_user(s32.data[i].value, &stats->data[i].value)
+                    || __get_user(s32.data[i].type, &stats->data[i].type))
+                        return -EFAULT;
+
+        if (copy_to_user(argp, &s32, sizeof(s32)))
+                return -EFAULT;
+        return 0;
+}
+
+typedef struct drm_buf_desc32 {
+        int           count;     /**< Number of buffers of this size */
+        int           size;      /**< Size in bytes */
+        int           low_mark;  /**< Low water mark */
+        int           high_mark; /**< High water mark */
+        int           flags;
+        u32           agp_start; /**< Start address in the AGP aperture */
+} drm_buf_desc32_t;
+
+static int compat_drm_addbufs(struct file *file, unsigned int cmd,
+                              unsigned long arg)
+{
+        drm_buf_desc32_t __user *argp = (void __user *)arg;
+        drm_buf_desc_t __user *buf;
+        int err;
+        unsigned long agp_start;
+
+        buf = compat_alloc_user_space(sizeof(*buf));
+        if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf))
+            || !access_ok(VERIFY_WRITE, argp, sizeof(*argp)))
+                return -EFAULT;
+
+        if (__copy_in_user(buf, argp, offsetof(drm_buf_desc32_t, agp_start))
+            || __get_user(agp_start, &argp->agp_start)
+            || __put_user(agp_start, &buf->agp_start))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_ADD_BUFS, (unsigned long) buf);
+        if (err)
+                return err;
+
+        if (__copy_in_user(argp, buf, offsetof(drm_buf_desc32_t, agp_start))
+            || __get_user(agp_start, &buf->agp_start)
+            || __put_user(agp_start, &argp->agp_start))
+                return -EFAULT;
+
+        return 0;
+}
+
+static int compat_drm_markbufs(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+        drm_buf_desc32_t b32;
+        drm_buf_desc32_t __user *argp = (void __user *)arg;
+        drm_buf_desc_t __user *buf;
+
+        if (copy_from_user(&b32, argp, sizeof(b32)))
+                return -EFAULT;
+
+        buf = compat_alloc_user_space(sizeof(*buf));
+        if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf)))
+                return -EFAULT;
+
+        if (__put_user(b32.size, &buf->size)
+            || __put_user(b32.low_mark, &buf->low_mark)
+            || __put_user(b32.high_mark, &buf->high_mark))
+                return -EFAULT;
+
+        return drm_ioctl(file->f_dentry->d_inode, file,
+                         DRM_IOCTL_MARK_BUFS, (unsigned long) buf);
+}
+
+typedef struct drm_buf_info32 {
+        int            count;   /**< Entries in list */
+        u32            list;
+} drm_buf_info32_t;
+
+static int compat_drm_infobufs(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+        drm_buf_info32_t req32;
+        drm_buf_info32_t __user *argp = (void __user *)arg;
+        drm_buf_desc32_t __user *to;
+        drm_buf_info_t __user *request;
+        drm_buf_desc_t __user *list;
+        size_t nbytes;
+        int i, err;
+        int count, actual;
+
+        if (copy_from_user(&req32, argp, sizeof(req32)))
+                return -EFAULT;
+
+        count = req32.count;
+        to = (drm_buf_desc32_t __user *)(unsigned long) req32.list;
+        if (count < 0)
+                count = 0;
+        if (count > 0
+            && !access_ok(VERIFY_WRITE, to, count * sizeof(drm_buf_desc32_t)))
+                return -EFAULT;
+
+        nbytes = sizeof(*request) + count * sizeof(drm_buf_desc_t);
+        request = compat_alloc_user_space(nbytes);
+        if (!access_ok(VERIFY_WRITE, request, nbytes))
+                return -EFAULT;
+        list = (drm_buf_desc_t *) (request + 1);
+
+        if (__put_user(count, &request->count)
+            || __put_user(list, &request->list))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_INFO_BUFS, (unsigned long) request);
+        if (err)
+                return err;
+
+        if (__get_user(actual, &request->count))
+                return -EFAULT;
+        if (count >= actual)
+                for (i = 0; i < actual; ++i)
+                        if (__copy_in_user(&to[i], &list[i],
+                                           offsetof(drm_buf_desc_t, flags)))
+                                return -EFAULT;
+
+        if (__put_user(actual, &argp->count))
+                return -EFAULT;
+
+        return 0;
+}
+
+typedef struct drm_buf_pub32 {
+        int     idx;            /**< Index into the master buffer list */
+        int     total;          /**< Buffer size */
+        int     used;           /**< Amount of buffer in use (for DMA) */
+        u32     address;        /**< Address of buffer */
+} drm_buf_pub32_t;
+
+typedef struct drm_buf_map32 {
+        int     count;          /**< Length of the buffer list */
+        u32     virtual;        /**< Mmap'd area in user-virtual */
+        u32     list;           /**< Buffer information */
+} drm_buf_map32_t;
+
+static int compat_drm_mapbufs(struct file *file, unsigned int cmd,
+                              unsigned long arg)
+{
+        drm_buf_map32_t __user *argp = (void __user *)arg;
+        drm_buf_map32_t req32;
+        drm_buf_pub32_t __user *list32;
+        drm_buf_map_t __user *request;
+        drm_buf_pub_t __user *list;
+        int i, err;
+        int count, actual;
+        size_t nbytes;
+        void __user *addr;
+
+        if (copy_from_user(&req32, argp, sizeof(req32)))
+                return -EFAULT;
+        count = req32.count;
+        list32 = (void __user *)(unsigned long)req32.list;
+
+        if (count < 0)
+                return -EINVAL;
+        nbytes = sizeof(*request) + count * sizeof(drm_buf_pub_t);
+        request = compat_alloc_user_space(nbytes);
+        if (!access_ok(VERIFY_WRITE, request, nbytes))
+                return -EFAULT;
+        list = (drm_buf_pub_t *) (request + 1);
+
+        if (__put_user(count, &request->count)
+            || __put_user(list, &request->list))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_MAP_BUFS, (unsigned long) request);
+        if (err)
+                return err;
+
+        if (__get_user(actual, &request->count))
+                return -EFAULT;
+        if (count >= actual)
+                for (i = 0; i < actual; ++i)
+                        if (__copy_in_user(&list32[i], &list[i],
+                                           offsetof(drm_buf_pub_t, address))
+                            || __get_user(addr, &list[i].address)
+                            || __put_user((unsigned long) addr,
+                                          &list32[i].address))
+                                return -EFAULT;
+
+        if (__put_user(actual, &argp->count)
+            || __get_user(addr, &request->virtual)
+            || __put_user((unsigned long) addr, &argp->virtual))
+                return -EFAULT;
+
+        return 0;
+}
+
+typedef struct drm_buf_free32 {
+        int     count;
+        u32     list;
+} drm_buf_free32_t;
+
+static int compat_drm_freebufs(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+        drm_buf_free32_t req32;
+        drm_buf_free_t __user *request;
+        drm_buf_free32_t __user *argp = (void __user *)arg;
+
+        if (copy_from_user(&req32, argp, sizeof(req32)))
+                return -EFAULT;
+
+        request = compat_alloc_user_space(sizeof(*request));
+        if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
+                return -EFAULT;
+        if (__put_user(req32.count, &request->count)
+            || __put_user((int __user *)(unsigned long) req32.list,
+                          &request->list))
+                return -EFAULT;
+
+        return drm_ioctl(file->f_dentry->d_inode, file,
+                         DRM_IOCTL_FREE_BUFS, (unsigned long) request);
+}
+
+typedef struct drm_ctx_priv_map32 {
+        unsigned int    ctx_id;  /**< Context requesting private mapping */
+        u32             handle; /**< Handle of map */
+} drm_ctx_priv_map32_t;
+
+static int compat_drm_setsareactx(struct file *file, unsigned int cmd,
+                                  unsigned long arg)
+{
+        drm_ctx_priv_map32_t req32;
+        drm_ctx_priv_map_t __user *request;
+        drm_ctx_priv_map32_t __user *argp = (void __user *)arg;
+
+        if (copy_from_user(&req32, argp, sizeof(req32)))
+                return -EFAULT;
+
+        request = compat_alloc_user_space(sizeof(*request));
+        if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
+                return -EFAULT;
+        if (__put_user(req32.ctx_id, &request->ctx_id)
+            || __put_user((void *)(unsigned long) req32.handle,
+                          &request->handle))
+                return -EFAULT;
+
+        return drm_ioctl(file->f_dentry->d_inode, file,
+                         DRM_IOCTL_SET_SAREA_CTX, (unsigned long) request);
+}
+
+static int compat_drm_getsareactx(struct file *file, unsigned int cmd,
+                                  unsigned long arg)
+{
+        drm_ctx_priv_map_t __user *request;
+        drm_ctx_priv_map32_t __user *argp = (void __user *)arg;
+        int err;
+        unsigned int ctx_id;
+        void *handle;
+
+        if (!access_ok(VERIFY_WRITE, argp, sizeof(*argp))
+            || __get_user(ctx_id, &argp->ctx_id))
+                return -EFAULT;
+
+        request = compat_alloc_user_space(sizeof(*request));
+        if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
+                return -EFAULT;
+        if (__put_user(ctx_id, &request->ctx_id))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_GET_SAREA_CTX, (unsigned long) request);
+        if (err)
+                return err;
+
+        if (__get_user(handle, &request->handle)
+            || __put_user((unsigned long) handle, &argp->handle))
+                return -EFAULT;
+
+        return 0;
+}
+
+typedef struct drm_ctx_res32 {
+        int     count;
+        u32     contexts;
+} drm_ctx_res32_t;
+
+static int compat_drm_resctx(struct file *file, unsigned int cmd,
+                             unsigned long arg)
+{
+        drm_ctx_res32_t __user *argp = (void __user *)arg;
+        drm_ctx_res32_t res32;
+        drm_ctx_res_t __user *res;
+        int err;
+
+        if (copy_from_user(&res32, argp, sizeof(res32)))
+                return -EFAULT;
+
+        res = compat_alloc_user_space(sizeof(*res));
+        if (!access_ok(VERIFY_WRITE, res, sizeof(*res)))
+                return -EFAULT;
+        if (__put_user(res32.count, &res->count)
+            || __put_user((drm_ctx_t __user *)(unsigned long) res32.contexts,
+                          &res->contexts))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_RES_CTX, (unsigned long) res);
+        if (err)
+                return err;
+
+        if (__get_user(res32.count, &res->count)
+            || __put_user(res32.count, &argp->count))
+                return -EFAULT;
+
+        return 0;
+}
+
+typedef struct drm_dma32 {
+        int     context;          /**< Context handle */
+        int     send_count;       /**< Number of buffers to send */
+        u32     send_indices;     /**< List of handles to buffers */
+        u32     send_sizes;       /**< Lengths of data to send */
+        drm_dma_flags_t flags;            /**< Flags */
+        int     request_count;    /**< Number of buffers requested */
+        int     request_size;     /**< Desired size for buffers */
+        u32     request_indices;  /**< Buffer information */
+        u32     request_sizes;
+        int     granted_count;    /**< Number of buffers granted */
+} drm_dma32_t;
+
+static int compat_drm_dma(struct file *file, unsigned int cmd,
+                          unsigned long arg)
+{
+        drm_dma32_t d32;
+        drm_dma32_t __user *argp = (void __user *) arg;
+        drm_dma_t __user *d;
+        int err;
+
+        if (copy_from_user(&d32, argp, sizeof(d32)))
+                return -EFAULT;
+
+        d = compat_alloc_user_space(sizeof(*d));
+        if (!access_ok(VERIFY_WRITE, d, sizeof(*d)))
+                return -EFAULT;
+
+        if (__put_user(d32.context, &d->context)
+            || __put_user(d32.send_count, &d->send_count)
+            || __put_user((int __user *)(unsigned long) d32.send_indices,
+                          &d->send_indices)
+            || __put_user((int __user *)(unsigned long) d32.send_sizes,
+                          &d->send_sizes)
+            || __put_user(d32.flags, &d->flags)
+            || __put_user(d32.request_count, &d->request_count)
+            || __put_user((int __user *)(unsigned long) d32.request_indices,
+                          &d->request_indices)
+            || __put_user((int __user *)(unsigned long) d32.request_sizes,
+                          &d->request_sizes))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_DMA, (unsigned long) d);
+        if (err)
+                return err;
+
+        if (__get_user(d32.request_size, &d->request_size)
+            || __get_user(d32.granted_count, &d->granted_count)
+            || __put_user(d32.request_size, &argp->request_size)
+            || __put_user(d32.granted_count, &argp->granted_count))
+                return -EFAULT;
+
+        return 0;
+}
+
+#if __OS_HAS_AGP
+typedef struct drm_agp_mode32 {
+        u32 mode;       /**< AGP mode */
+} drm_agp_mode32_t;
+
+static int compat_drm_agp_enable(struct file *file, unsigned int cmd,
+                                 unsigned long arg)
+{
+        drm_agp_mode32_t __user *argp = (void __user *)arg;
+        drm_agp_mode32_t m32;
+        drm_agp_mode_t __user *mode;
+
+        if (get_user(m32.mode, &argp->mode))
+                return -EFAULT;
+
+        mode = compat_alloc_user_space(sizeof(*mode));
+        if (put_user(m32.mode, &mode->mode))
+                return -EFAULT;
+
+        return drm_ioctl(file->f_dentry->d_inode, file,
+                         DRM_IOCTL_AGP_ENABLE, (unsigned long) mode);
+}
+
+typedef struct drm_agp_info32 {
+        int       agp_version_major;
+        int       agp_version_minor;
+        u32       mode;
+        u32       aperture_base;  /* physical address */
+        u32       aperture_size;  /* bytes */
+        u32       memory_allowed; /* bytes */
+        u32       memory_used;
+
+                                /* PCI information */
+        unsigned short id_vendor;
+        unsigned short id_device;
+} drm_agp_info32_t;
+
+static int compat_drm_agp_info(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+        drm_agp_info32_t __user *argp = (void __user *)arg;
+        drm_agp_info32_t i32;
+        drm_agp_info_t __user *info;
+        int err;
+
+        info = compat_alloc_user_space(sizeof(*info));
+        if (!access_ok(VERIFY_WRITE, info, sizeof(*info)))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_AGP_INFO, (unsigned long) info);
+        if (err)
+                return err;
+
+        if (__get_user(i32.agp_version_major, &info->agp_version_major)
+            || __get_user(i32.agp_version_minor, &info->agp_version_minor)
+            || __get_user(i32.mode, &info->mode)
+            || __get_user(i32.aperture_base, &info->aperture_base)
+            || __get_user(i32.aperture_size, &info->aperture_size)
+            || __get_user(i32.memory_allowed, &info->memory_allowed)
+            || __get_user(i32.memory_used, &info->memory_used)
+            || __get_user(i32.id_vendor, &info->id_vendor)
+            || __get_user(i32.id_device, &info->id_device))
+                return -EFAULT;
+
+        if (copy_to_user(argp, &i32, sizeof(i32)))
+                return -EFAULT;
+
+        return 0;
+}
+
+typedef struct drm_agp_buffer32 {
+        u32 size;       /**< In bytes -- will round to page boundary */
+        u32 handle;     /**< Used for binding / unbinding */
+        u32 type;       /**< Type of memory to allocate */
+        u32 physical;   /**< Physical used by i810 */
+} drm_agp_buffer32_t;
+
+static int compat_drm_agp_alloc(struct file *file, unsigned int cmd,
+                                unsigned long arg)
+{
+        drm_agp_buffer32_t __user *argp = (void __user *)arg;
+        drm_agp_buffer32_t req32;
+        drm_agp_buffer_t __user *request;
+        int err;
+
+        if (copy_from_user(&req32, argp, sizeof(req32)))
+                return -EFAULT;
+
+        request = compat_alloc_user_space(sizeof(*request));
+        if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+            || __put_user(req32.size, &request->size)
+            || __put_user(req32.type, &request->type))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_AGP_ALLOC, (unsigned long) request);
+        if (err)
+                return err;
+
+        if (__get_user(req32.handle, &request->handle)
+            || __get_user(req32.physical, &request->physical)
+            || copy_to_user(argp, &req32, sizeof(req32))) {
+                drm_ioctl(file->f_dentry->d_inode, file,
+                          DRM_IOCTL_AGP_FREE, (unsigned long) request);
+                return -EFAULT;
+        }
+
+        return 0;
+}
+
+static int compat_drm_agp_free(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+        drm_agp_buffer32_t __user *argp = (void __user *)arg;
+        drm_agp_buffer_t __user *request;
+        u32 handle;
+
+        request = compat_alloc_user_space(sizeof(*request));
+        if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+            || get_user(handle, &argp->handle)
+            || __put_user(handle, &request->handle))
+                return -EFAULT;
+
+        return drm_ioctl(file->f_dentry->d_inode, file,
+                         DRM_IOCTL_AGP_FREE, (unsigned long) request);
+}
+
+typedef struct drm_agp_binding32 {
+        u32 handle;     /**< From drm_agp_buffer */
+        u32 offset;     /**< In bytes -- will round to page boundary */
+} drm_agp_binding32_t;
+
+static int compat_drm_agp_bind(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+        drm_agp_binding32_t __user *argp = (void __user *)arg;
+        drm_agp_binding32_t req32;
+        drm_agp_binding_t __user *request;
+
+        if (copy_from_user(&req32, argp, sizeof(req32)))
+                return -EFAULT;
+
+        request = compat_alloc_user_space(sizeof(*request));
+        if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+            || __put_user(req32.handle, &request->handle)
+            || __put_user(req32.offset, &request->offset))
+                return -EFAULT;
+
+        return drm_ioctl(file->f_dentry->d_inode, file,
+                         DRM_IOCTL_AGP_BIND, (unsigned long) request);
+}
+
+static int compat_drm_agp_unbind(struct file *file, unsigned int cmd,
+                                 unsigned long arg)
+{
+        drm_agp_binding32_t __user *argp = (void __user *)arg;
+        drm_agp_binding_t __user *request;
+        u32 handle;
+
+        request = compat_alloc_user_space(sizeof(*request));
+        if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+            || get_user(handle, &argp->handle)
+            || __put_user(handle, &request->handle))
+                return -EFAULT;
+
+        return drm_ioctl(file->f_dentry->d_inode, file,
+                         DRM_IOCTL_AGP_UNBIND, (unsigned long) request);
+}
+#endif /* __OS_HAS_AGP */
+
+typedef struct drm_scatter_gather32 {
+        u32 size;       /**< In bytes -- will round to page boundary */
+        u32 handle;     /**< Used for mapping / unmapping */
+} drm_scatter_gather32_t;
+
+static int compat_drm_sg_alloc(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+        drm_scatter_gather32_t __user *argp = (void __user *)arg;
+        drm_scatter_gather_t __user *request;
+        int err;
+        unsigned long x;
+
+        request = compat_alloc_user_space(sizeof(*request));
+        if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+            || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
+            || __get_user(x, &argp->size)
+            || __put_user(x, &request->size))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_SG_ALLOC, (unsigned long) request);
+        if (err)
+                return err;
+
+        /* XXX not sure about the handle conversion here... */
+        if (__get_user(x, &request->handle)
+            || __put_user(x >> PAGE_SHIFT, &argp->handle))
+                return -EFAULT;
+
+        return 0;
+}
+
+static int compat_drm_sg_free(struct file *file, unsigned int cmd,
+                              unsigned long arg)
+{
+        drm_scatter_gather32_t __user *argp = (void __user *)arg;
+        drm_scatter_gather_t __user *request;
+        unsigned long x;
+
+        request = compat_alloc_user_space(sizeof(*request));
+        if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+            || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
+            || __get_user(x, &argp->handle)
+            || __put_user(x << PAGE_SHIFT, &request->handle))
+                return -EFAULT;
+
+        return drm_ioctl(file->f_dentry->d_inode, file,
+                         DRM_IOCTL_SG_FREE, (unsigned long) request);
+}
+
+struct drm_wait_vblank_request32 {
+        drm_vblank_seq_type_t type;
+        unsigned int sequence;
+        u32 signal;
+};
+
+struct drm_wait_vblank_reply32 {
+        drm_vblank_seq_type_t type;
+        unsigned int sequence;
+        s32 tval_sec;
+        s32 tval_usec;
+};
+
+typedef union drm_wait_vblank32 {
+        struct drm_wait_vblank_request32 request;
+        struct drm_wait_vblank_reply32 reply;
+} drm_wait_vblank32_t;
+
+static int compat_drm_wait_vblank(struct file *file, unsigned int cmd,
+                                  unsigned long arg)
+{
+        drm_wait_vblank32_t __user *argp = (void __user *)arg;
+        drm_wait_vblank32_t req32;
+        drm_wait_vblank_t __user *request;
+        int err;
+
+        if (copy_from_user(&req32, argp, sizeof(req32)))
+                return -EFAULT;
+
+        request = compat_alloc_user_space(sizeof(*request));
+        if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+            || __put_user(req32.request.type, &request->request.type)
+            || __put_user(req32.request.sequence, &request->request.sequence)
+            || __put_user(req32.request.signal, &request->request.signal))
+                return -EFAULT;
+
+        err = drm_ioctl(file->f_dentry->d_inode, file,
+                        DRM_IOCTL_WAIT_VBLANK, (unsigned long) request);
+        if (err)
+                return err;
+
+        if (__get_user(req32.reply.type, &request->reply.type)
+            || __get_user(req32.reply.sequence, &request->reply.sequence)
+            || __get_user(req32.reply.tval_sec, &request->reply.tval_sec)
+            || __get_user(req32.reply.tval_usec, &request->reply.tval_usec))
+                return -EFAULT;
+
+        if (copy_to_user(argp, &req32, sizeof(req32)))
+                return -EFAULT;
+
+        return 0;
+}
+
+drm_ioctl_compat_t *drm_compat_ioctls[] = {
+        [DRM_IOCTL_NR(DRM_IOCTL_VERSION32)] = compat_drm_version,
+        [DRM_IOCTL_NR(DRM_IOCTL_GET_UNIQUE32)] = compat_drm_getunique,
+        [DRM_IOCTL_NR(DRM_IOCTL_GET_MAP32)] = compat_drm_getmap,
+        [DRM_IOCTL_NR(DRM_IOCTL_GET_CLIENT32)] = compat_drm_getclient,
+        [DRM_IOCTL_NR(DRM_IOCTL_GET_STATS32)] = compat_drm_getstats,
+        [DRM_IOCTL_NR(DRM_IOCTL_SET_UNIQUE32)] = compat_drm_setunique,
+        [DRM_IOCTL_NR(DRM_IOCTL_ADD_MAP32)] = compat_drm_addmap,
+        [DRM_IOCTL_NR(DRM_IOCTL_ADD_BUFS32)] = compat_drm_addbufs,
+        [DRM_IOCTL_NR(DRM_IOCTL_MARK_BUFS32)] = compat_drm_markbufs,
+        [DRM_IOCTL_NR(DRM_IOCTL_INFO_BUFS32)] = compat_drm_infobufs,
+        [DRM_IOCTL_NR(DRM_IOCTL_MAP_BUFS32)] = compat_drm_mapbufs,
+        [DRM_IOCTL_NR(DRM_IOCTL_FREE_BUFS32)] = compat_drm_freebufs,
+        [DRM_IOCTL_NR(DRM_IOCTL_RM_MAP32)] = compat_drm_rmmap,
+        [DRM_IOCTL_NR(DRM_IOCTL_SET_SAREA_CTX32)] = compat_drm_setsareactx,
+        [DRM_IOCTL_NR(DRM_IOCTL_GET_SAREA_CTX32)] = compat_drm_getsareactx,
+        [DRM_IOCTL_NR(DRM_IOCTL_RES_CTX32)] = compat_drm_resctx,
+        [DRM_IOCTL_NR(DRM_IOCTL_DMA32)] = compat_drm_dma,
+#if __OS_HAS_AGP
+        [DRM_IOCTL_NR(DRM_IOCTL_AGP_ENABLE32)] = compat_drm_agp_enable,
+        [DRM_IOCTL_NR(DRM_IOCTL_AGP_INFO32)] = compat_drm_agp_info,
+        [DRM_IOCTL_NR(DRM_IOCTL_AGP_ALLOC32)] = compat_drm_agp_alloc,
+        [DRM_IOCTL_NR(DRM_IOCTL_AGP_FREE32)] = compat_drm_agp_free,
+        [DRM_IOCTL_NR(DRM_IOCTL_AGP_BIND32)] = compat_drm_agp_bind,
+        [DRM_IOCTL_NR(DRM_IOCTL_AGP_UNBIND32)] = compat_drm_agp_unbind,
+#endif
+        [DRM_IOCTL_NR(DRM_IOCTL_SG_ALLOC32)] = compat_drm_sg_alloc,
+        [DRM_IOCTL_NR(DRM_IOCTL_SG_FREE32)] = compat_drm_sg_free,
+        [DRM_IOCTL_NR(DRM_IOCTL_WAIT_VBLANK32)] = compat_drm_wait_vblank,
+};
+
+/**
+ * Called whenever a 32-bit process running under a 64-bit kernel
+ * performs an ioctl on /dev/drm.
+ *
+ * \param filp file pointer.
+ * \param cmd command.
+ * \param arg user argument.
+ * \return zero on success or negative number on failure.
+ */
+long drm_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+        unsigned int nr = DRM_IOCTL_NR(cmd);
+        drm_ioctl_compat_t *fn;
+        int ret;
+
+        if (nr >= DRM_ARRAY_SIZE(drm_compat_ioctls))
+                return -ENOTTY;
+
+        fn = drm_compat_ioctls[nr];
+
+        lock_kernel();          /* XXX for now */
+        if (fn != NULL)
+                ret = (*fn)(filp, cmd, arg);
+        else
+                ret = drm_ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
+        unlock_kernel();
+
+        return ret;
+}
+EXPORT_SYMBOL(drm_compat_ioctl);