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 #include "drmP.h"
34 #include <linux/poll.h>
35
36 /* drm_open is called whenever a process opens /dev/drm. */
37
DRM(open_helper)38 int DRM(open_helper)(struct inode *inode, struct file *filp, drm_device_t *dev)
39 {
40 int minor = minor(inode->i_rdev);
41 drm_file_t *priv;
42
43 if (filp->f_flags & O_EXCL) return -EBUSY; /* No exclusive opens */
44 if (!DRM(cpu_valid)()) return -EINVAL;
45
46 DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
47
48 priv = DRM(alloc)(sizeof(*priv), DRM_MEM_FILES);
49 if(!priv) return -ENOMEM;
50
51 memset(priv, 0, sizeof(*priv));
52 filp->private_data = priv;
53 priv->uid = current->euid;
54 priv->pid = current->pid;
55 priv->minor = minor;
56 priv->dev = dev;
57 priv->ioctl_count = 0;
58 priv->authenticated = capable(CAP_SYS_ADMIN);
59
60 down(&dev->struct_sem);
61 if (!dev->file_last) {
62 priv->next = NULL;
63 priv->prev = NULL;
64 dev->file_first = priv;
65 dev->file_last = priv;
66 } else {
67 priv->next = NULL;
68 priv->prev = dev->file_last;
69 dev->file_last->next = priv;
70 dev->file_last = priv;
71 }
72 up(&dev->struct_sem);
73
74 #ifdef __alpha__
75 /*
76 * Default the hose
77 */
78 if (!dev->hose) {
79 struct pci_dev *pci_dev;
80 pci_dev = pci_find_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
81 if (pci_dev) dev->hose = pci_dev->sysdata;
82 if (!dev->hose) {
83 struct pci_bus *b = pci_bus_b(pci_root_buses.next);
84 if (b) dev->hose = b->sysdata;
85 }
86 }
87 #endif
88
89 return 0;
90 }
91
DRM(flush)92 int DRM(flush)(struct file *filp)
93 {
94 drm_file_t *priv = filp->private_data;
95 drm_device_t *dev = priv->dev;
96
97 DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
98 current->pid, (long)dev->device, dev->open_count);
99 return 0;
100 }
101
DRM(fasync)102 int DRM(fasync)(int fd, struct file *filp, int on)
103 {
104 drm_file_t *priv = filp->private_data;
105 drm_device_t *dev = priv->dev;
106 int retcode;
107
108 DRM_DEBUG("fd = %d, device = 0x%lx\n", fd, (long)dev->device);
109 retcode = fasync_helper(fd, filp, on, &dev->buf_async);
110 if (retcode < 0) return retcode;
111 return 0;
112 }
113
114
115 /* The drm_read and drm_write_string code (especially that which manages
116 the circular buffer), is based on Alessandro Rubini's LINUX DEVICE
117 DRIVERS (Cambridge: O'Reilly, 1998), pages 111-113. */
118
DRM(read)119 ssize_t DRM(read)(struct file *filp, char *buf, size_t count, loff_t *off)
120 {
121 drm_file_t *priv = filp->private_data;
122 drm_device_t *dev = priv->dev;
123 int left;
124 int avail;
125 int send;
126 int cur;
127 DECLARE_WAITQUEUE(wait, current);
128
129 DRM_DEBUG("%p, %p\n", dev->buf_rp, dev->buf_wp);
130
131 add_wait_queue(&dev->buf_readers, &wait);
132 set_current_state(TASK_INTERRUPTIBLE);
133 while (dev->buf_rp == dev->buf_wp) {
134 DRM_DEBUG(" sleeping\n");
135 if (filp->f_flags & O_NONBLOCK) {
136 remove_wait_queue(&dev->buf_readers, &wait);
137 set_current_state(TASK_RUNNING);
138 return -EAGAIN;
139 }
140 schedule(); /* wait for dev->buf_readers */
141 if (signal_pending(current)) {
142 DRM_DEBUG(" interrupted\n");
143 remove_wait_queue(&dev->buf_readers, &wait);
144 set_current_state(TASK_RUNNING);
145 return -ERESTARTSYS;
146 }
147 DRM_DEBUG(" awake\n");
148 set_current_state(TASK_INTERRUPTIBLE);
149 }
150 remove_wait_queue(&dev->buf_readers, &wait);
151 set_current_state(TASK_RUNNING);
152
153 left = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
154 avail = DRM_BSZ - left;
155 send = DRM_MIN(avail, count);
156
157 while (send) {
158 if (dev->buf_wp > dev->buf_rp) {
159 cur = DRM_MIN(send, dev->buf_wp - dev->buf_rp);
160 } else {
161 cur = DRM_MIN(send, dev->buf_end - dev->buf_rp);
162 }
163 if (copy_to_user(buf, dev->buf_rp, cur))
164 return -EFAULT;
165 dev->buf_rp += cur;
166 if (dev->buf_rp == dev->buf_end) dev->buf_rp = dev->buf;
167 send -= cur;
168 }
169
170 wake_up_interruptible(&dev->buf_writers);
171 return DRM_MIN(avail, count);;
172 }
173
DRM(write_string)174 int DRM(write_string)(drm_device_t *dev, const char *s)
175 {
176 int left = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
177 int send = strlen(s);
178 int count;
179
180 DRM_DEBUG("%d left, %d to send (%p, %p)\n",
181 left, send, dev->buf_rp, dev->buf_wp);
182
183 if (left == 1 || dev->buf_wp != dev->buf_rp) {
184 DRM_ERROR("Buffer not empty (%d left, wp = %p, rp = %p)\n",
185 left,
186 dev->buf_wp,
187 dev->buf_rp);
188 }
189
190 while (send) {
191 if (dev->buf_wp >= dev->buf_rp) {
192 count = DRM_MIN(send, dev->buf_end - dev->buf_wp);
193 if (count == left) --count; /* Leave a hole */
194 } else {
195 count = DRM_MIN(send, dev->buf_rp - dev->buf_wp - 1);
196 }
197 strncpy(dev->buf_wp, s, count);
198 dev->buf_wp += count;
199 if (dev->buf_wp == dev->buf_end) dev->buf_wp = dev->buf;
200 send -= count;
201 }
202
203 if (dev->buf_async) kill_fasync(&dev->buf_async, SIGIO, POLL_IN);
204
205 DRM_DEBUG("waking\n");
206 wake_up_interruptible(&dev->buf_readers);
207 return 0;
208 }
209
DRM(poll)210 unsigned int DRM(poll)(struct file *filp, struct poll_table_struct *wait)
211 {
212 drm_file_t *priv = filp->private_data;
213 drm_device_t *dev = priv->dev;
214
215 poll_wait(filp, &dev->buf_readers, wait);
216 if (dev->buf_wp != dev->buf_rp) return POLLIN | POLLRDNORM;
217 return 0;
218 }
219