1 /* fops.c -- File operations for DRM -*- linux-c -*-
2 * Created: Mon Jan 4 08:58:31 1999 by faith@precisioninsight.com
3 * Revised: Fri Aug 20 11:31:46 1999 by faith@precisioninsight.com
5 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
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:
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
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 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
23 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
24 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
25 * DEALINGS IN THE SOFTWARE.
27 * $PI: xc/programs/Xserver/hw/xfree86/os-support/linux/drm/generic/fops.c,v 1.3 1999/08/20 15:36:45 faith Exp $
32 #define __NO_VERSION__
35 /* drm_open is called whenever a process opens /dev/drm. */
37 int drm_open_helper(struct inode
*inode
, struct file
*filp
, drm_device_t
*dev
)
39 kdev_t minor
= MINOR(inode
->i_rdev
);
42 if (filp
->f_flags
& O_EXCL
) return -EBUSY
; /* No exclusive opens */
44 DRM_DEBUG("pid = %d, minor = %d\n", current
->pid
, minor
);
46 priv
= drm_alloc(sizeof(*priv
), DRM_MEM_FILES
);
47 memset(priv
, 0, sizeof(*priv
));
48 filp
->private_data
= priv
;
49 priv
->uid
= current
->euid
;
50 priv
->pid
= current
->pid
;
53 priv
->ioctl_count
= 0;
54 priv
->authenticated
= capable(CAP_SYS_ADMIN
);
56 down(&dev
->struct_sem
);
57 if (!dev
->file_last
) {
60 dev
->file_first
= priv
;
61 dev
->file_last
= priv
;
64 priv
->prev
= dev
->file_last
;
65 dev
->file_last
->next
= priv
;
66 dev
->file_last
= priv
;
73 int drm_flush(struct file
*filp
)
75 drm_file_t
*priv
= filp
->private_data
;
76 drm_device_t
*dev
= priv
->dev
;
78 DRM_DEBUG("pid = %d, device = 0x%x, open_count = %d, f_count = %d\n",
79 current
->pid
, dev
->device
, dev
->open_count
, filp
->f_count
);
83 /* drm_release is called whenever a process closes /dev/drm*. Linux calls
84 this only if any mappings have been closed. */
86 int drm_release(struct inode
*inode
, struct file
*filp
)
88 drm_file_t
*priv
= filp
->private_data
;
89 drm_device_t
*dev
= priv
->dev
;
91 DRM_DEBUG("pid = %d, device = 0x%x, open_count = %d\n",
92 current
->pid
, dev
->device
, dev
->open_count
);
94 drm_reclaim_buffers(dev
, priv
->pid
);
96 drm_fasync(-1, filp
, 0);
98 down(&dev
->struct_sem
);
99 if (priv
->prev
) priv
->prev
->next
= priv
->next
;
100 else dev
->file_first
= priv
->next
;
101 if (priv
->next
) priv
->next
->prev
= priv
->prev
;
102 else dev
->file_last
= priv
->prev
;
103 up(&dev
->struct_sem
);
105 drm_free(priv
, sizeof(*priv
), DRM_MEM_FILES
);
110 int drm_fasync(int fd
, struct file
*filp
, int on
)
112 drm_file_t
*priv
= filp
->private_data
;
113 drm_device_t
*dev
= priv
->dev
;
116 DRM_DEBUG("fd = %d, device = 0x%x\n", fd
, dev
->device
);
117 retcode
= fasync_helper(fd
, filp
, on
, &dev
->buf_async
);
118 if (retcode
< 0) return retcode
;
123 /* The drm_read and drm_write_string code (especially that which manages
124 the circular buffer), is based on Alessandro Rubini's LINUX DEVICE
125 DRIVERS (Cambridge: O'Reilly, 1998), pages 111-113. */
127 ssize_t
drm_read(struct file
*filp
, char *buf
, size_t count
, loff_t
*off
)
129 drm_file_t
*priv
= filp
->private_data
;
130 drm_device_t
*dev
= priv
->dev
;
136 DRM_DEBUG("%p, %p\n", dev
->buf_rp
, dev
->buf_wp
);
138 while (dev
->buf_rp
== dev
->buf_wp
) {
139 DRM_DEBUG(" sleeping\n");
140 if (filp
->f_flags
& O_NONBLOCK
) {
143 interruptible_sleep_on(&dev
->buf_readers
);
144 if (signal_pending(current
)) {
145 DRM_DEBUG(" interrupted\n");
148 DRM_DEBUG(" awake\n");
151 left
= (dev
->buf_rp
+ DRM_BSZ
- dev
->buf_wp
) % DRM_BSZ
;
152 avail
= DRM_BSZ
- left
;
153 send
= DRM_MIN(avail
, count
);
156 if (dev
->buf_wp
> dev
->buf_rp
) {
157 cur
= DRM_MIN(send
, dev
->buf_wp
- dev
->buf_rp
);
159 cur
= DRM_MIN(send
, dev
->buf_end
- dev
->buf_rp
);
161 copy_to_user_ret(buf
, dev
->buf_rp
, cur
, -EINVAL
);
163 if (dev
->buf_rp
== dev
->buf_end
) dev
->buf_rp
= dev
->buf
;
167 wake_up_interruptible(&dev
->buf_writers
);
168 return DRM_MIN(avail
, count
);;
171 int drm_write_string(drm_device_t
*dev
, const char *s
)
173 int left
= (dev
->buf_rp
+ DRM_BSZ
- dev
->buf_wp
) % DRM_BSZ
;
174 int send
= strlen(s
);
177 DRM_DEBUG("%d left, %d to send (%p, %p)\n",
178 left
, send
, dev
->buf_rp
, dev
->buf_wp
);
180 if (left
== 1 || dev
->buf_wp
!= dev
->buf_rp
) {
181 DRM_ERROR("Buffer not empty (%d left, wp = %p, rp = %p)\n",
188 if (dev
->buf_wp
>= dev
->buf_rp
) {
189 count
= DRM_MIN(send
, dev
->buf_end
- dev
->buf_wp
);
190 if (count
== left
) --count
; /* Leave a hole */
192 count
= DRM_MIN(send
, dev
->buf_rp
- dev
->buf_wp
- 1);
194 strncpy(dev
->buf_wp
, s
, count
);
195 dev
->buf_wp
+= count
;
196 if (dev
->buf_wp
== dev
->buf_end
) dev
->buf_wp
= dev
->buf
;
200 if (dev
->buf_async
) kill_fasync(dev
->buf_async
, SIGIO
);
201 DRM_DEBUG("waking\n");
202 wake_up_interruptible(&dev
->buf_readers
);