File: /usr/src/linux/drivers/char/drm/drm_fops.h
1 /* drm_fops.h -- File operations for DRM -*- linux-c -*-
2 * Created: Mon Jan 4 08:58:31 1999 by faith@valinux.com
3 *
4 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
5 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
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 * VA LINUX SYSTEMS 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
25 * OTHER DEALINGS IN THE SOFTWARE.
26 *
27 * Authors:
28 * Rickard E. (Rik) Faith <faith@valinux.com>
29 * Daryll Strauss <daryll@valinux.com>
30 * Gareth Hughes <gareth@valinux.com>
31 */
32
33 #define __NO_VERSION__
34 #include "drmP.h"
35 #include <linux/poll.h>
36
37 /* drm_open is called whenever a process opens /dev/drm. */
38
39 int DRM(open_helper)(struct inode *inode, struct file *filp, drm_device_t *dev)
40 {
41 kdev_t minor = MINOR(inode->i_rdev);
42 drm_file_t *priv;
43
44 if (filp->f_flags & O_EXCL) return -EBUSY; /* No exclusive opens */
45 if (!DRM(cpu_valid)()) return -EINVAL;
46
47 DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
48
49 priv = DRM(alloc)(sizeof(*priv), DRM_MEM_FILES);
50 if(!priv) return -ENOMEM;
51
52 memset(priv, 0, sizeof(*priv));
53 filp->private_data = priv;
54 priv->uid = current->euid;
55 priv->pid = current->pid;
56 priv->minor = minor;
57 priv->dev = dev;
58 priv->ioctl_count = 0;
59 priv->authenticated = capable(CAP_SYS_ADMIN);
60
61 down(&dev->struct_sem);
62 if (!dev->file_last) {
63 priv->next = NULL;
64 priv->prev = NULL;
65 dev->file_first = priv;
66 dev->file_last = priv;
67 } else {
68 priv->next = NULL;
69 priv->prev = dev->file_last;
70 dev->file_last->next = priv;
71 dev->file_last = priv;
72 }
73 up(&dev->struct_sem);
74
75 #ifdef __alpha__
76 /*
77 * Default the hose
78 */
79 if (!dev->hose) {
80 struct pci_dev *pci_dev;
81 pci_dev = pci_find_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
82 if (pci_dev) dev->hose = pci_dev->sysdata;
83 if (!dev->hose) {
84 struct pci_bus *b = pci_bus_b(pci_root_buses.next);
85 if (b) dev->hose = b->sysdata;
86 }
87 }
88 #endif
89
90 return 0;
91 }
92
93 int DRM(flush)(struct file *filp)
94 {
95 drm_file_t *priv = filp->private_data;
96 drm_device_t *dev = priv->dev;
97
98 DRM_DEBUG("pid = %d, device = 0x%x, open_count = %d\n",
99 current->pid, dev->device, dev->open_count);
100 return 0;
101 }
102
103 int DRM(fasync)(int fd, struct file *filp, int on)
104 {
105 drm_file_t *priv = filp->private_data;
106 drm_device_t *dev = priv->dev;
107 int retcode;
108
109 DRM_DEBUG("fd = %d, device = 0x%x\n", fd, dev->device);
110 retcode = fasync_helper(fd, filp, on, &dev->buf_async);
111 if (retcode < 0) return retcode;
112 return 0;
113 }
114
115
116 /* The drm_read and drm_write_string code (especially that which manages
117 the circular buffer), is based on Alessandro Rubini's LINUX DEVICE
118 DRIVERS (Cambridge: O'Reilly, 1998), pages 111-113. */
119
120 ssize_t DRM(read)(struct file *filp, char *buf, size_t count, loff_t *off)
121 {
122 drm_file_t *priv = filp->private_data;
123 drm_device_t *dev = priv->dev;
124 int left;
125 int avail;
126 int send;
127 int cur;
128
129 DRM_DEBUG("%p, %p\n", dev->buf_rp, dev->buf_wp);
130
131 while (dev->buf_rp == dev->buf_wp) {
132 DRM_DEBUG(" sleeping\n");
133 if (filp->f_flags & O_NONBLOCK) {
134 return -EAGAIN;
135 }
136 interruptible_sleep_on(&dev->buf_readers);
137 if (signal_pending(current)) {
138 DRM_DEBUG(" interrupted\n");
139 return -ERESTARTSYS;
140 }
141 DRM_DEBUG(" awake\n");
142 }
143
144 left = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
145 avail = DRM_BSZ - left;
146 send = DRM_MIN(avail, count);
147
148 while (send) {
149 if (dev->buf_wp > dev->buf_rp) {
150 cur = DRM_MIN(send, dev->buf_wp - dev->buf_rp);
151 } else {
152 cur = DRM_MIN(send, dev->buf_end - dev->buf_rp);
153 }
154 if (copy_to_user(buf, dev->buf_rp, cur))
155 return -EFAULT;
156 dev->buf_rp += cur;
157 if (dev->buf_rp == dev->buf_end) dev->buf_rp = dev->buf;
158 send -= cur;
159 }
160
161 wake_up_interruptible(&dev->buf_writers);
162 return DRM_MIN(avail, count);;
163 }
164
165 int DRM(write_string)(drm_device_t *dev, const char *s)
166 {
167 int left = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
168 int send = strlen(s);
169 int count;
170
171 DRM_DEBUG("%d left, %d to send (%p, %p)\n",
172 left, send, dev->buf_rp, dev->buf_wp);
173
174 if (left == 1 || dev->buf_wp != dev->buf_rp) {
175 DRM_ERROR("Buffer not empty (%d left, wp = %p, rp = %p)\n",
176 left,
177 dev->buf_wp,
178 dev->buf_rp);
179 }
180
181 while (send) {
182 if (dev->buf_wp >= dev->buf_rp) {
183 count = DRM_MIN(send, dev->buf_end - dev->buf_wp);
184 if (count == left) --count; /* Leave a hole */
185 } else {
186 count = DRM_MIN(send, dev->buf_rp - dev->buf_wp - 1);
187 }
188 strncpy(dev->buf_wp, s, count);
189 dev->buf_wp += count;
190 if (dev->buf_wp == dev->buf_end) dev->buf_wp = dev->buf;
191 send -= count;
192 }
193
194 #if LINUX_VERSION_CODE < 0x020315 && !defined(KILLFASYNCHASTHREEPARAMETERS)
195 /* The extra parameter to kill_fasync was added in 2.3.21, and is
196 _not_ present in _stock_ 2.2.14 and 2.2.15. However, some
197 distributions patch 2.2.x kernels to add this parameter. The
198 Makefile.linux attempts to detect this addition and defines
199 KILLFASYNCHASTHREEPARAMETERS if three parameters are found. */
200 if (dev->buf_async) kill_fasync(dev->buf_async, SIGIO);
201 #else
202
203 /* Parameter added in 2.3.21. */
204 #if LINUX_VERSION_CODE < 0x020400
205 if (dev->buf_async) kill_fasync(dev->buf_async, SIGIO, POLL_IN);
206 #else
207 /* Type of first parameter changed in
208 Linux 2.4.0-test2... */
209 if (dev->buf_async) kill_fasync(&dev->buf_async, SIGIO, POLL_IN);
210 #endif
211 #endif
212 DRM_DEBUG("waking\n");
213 wake_up_interruptible(&dev->buf_readers);
214 return 0;
215 }
216
217 unsigned int DRM(poll)(struct file *filp, struct poll_table_struct *wait)
218 {
219 drm_file_t *priv = filp->private_data;
220 drm_device_t *dev = priv->dev;
221
222 poll_wait(filp, &dev->buf_readers, wait);
223 if (dev->buf_wp != dev->buf_rp) return POLLIN | POLLRDNORM;
224 return 0;
225 }
226