summaryrefslogtreecommitdiff
path: root/linux/drm_fops.h
blob: 3656c5e9c17d40cbff1977f8d36528623c9a3487 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
/* drm_fops.h -- File operations for DRM -*- linux-c -*-
 * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
 *
 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * 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
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS 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.
 *
 * Authors:
 *    Rickard E. (Rik) Faith <faith@valinux.com>
 *    Daryll Strauss <daryll@valinux.com>
 *    Gareth Hughes <gareth@valinux.com>
 */

#define __NO_VERSION__
#include "drmP.h"
#include <linux/poll.h>

/* drm_open is called whenever a process opens /dev/drm. */

int DRM(open_helper)(struct inode *inode, struct file *filp, drm_device_t *dev)
{
	kdev_t	     minor = MINOR(inode->i_rdev);
	drm_file_t   *priv;

	if (filp->f_flags & O_EXCL)   return -EBUSY; /* No exclusive opens */
	if (!DRM(cpu_valid)())        return -EINVAL;

	DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);

	priv		    = DRM(alloc)(sizeof(*priv), DRM_MEM_FILES);
	if(!priv) return -ENOMEM;

	memset(priv, 0, sizeof(*priv));
	filp->private_data  = priv;
	priv->uid	    = current->euid;
	priv->pid	    = current->pid;
	priv->minor	    = minor;
	priv->dev	    = dev;
	priv->ioctl_count   = 0;
	priv->authenticated = capable(CAP_SYS_ADMIN);

	down(&dev->struct_sem);
	if (!dev->file_last) {
		priv->next	= NULL;
		priv->prev	= NULL;
		dev->file_first = priv;
		dev->file_last	= priv;
	} else {
		priv->next	     = NULL;
		priv->prev	     = dev->file_last;
		dev->file_last->next = priv;
		dev->file_last	     = priv;
	}
	up(&dev->struct_sem);

#ifdef __alpha__
	/*
	 * Default the hose
	 */
	if (!dev->hose) {
		struct pci_dev *pci_dev;
		pci_dev = pci_find_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
		if (pci_dev) dev->hose = pci_dev->sysdata;
		if (!dev->hose) {
			struct pci_bus *b = pci_bus_b(pci_root_buses.next);
			if (b) dev->hose = b->sysdata;
		}
	}
#endif

	return 0;
}

int DRM(flush)(struct file *filp)
{
	drm_file_t    *priv   = filp->private_data;
	drm_device_t  *dev    = priv->dev;

	DRM_DEBUG("pid = %d, device = 0x%x, open_count = %d\n",
		  current->pid, dev->device, dev->open_count);
	return 0;
}

int DRM(fasync)(int fd, struct file *filp, int on)
{
	drm_file_t    *priv   = filp->private_data;
	drm_device_t  *dev    = priv->dev;
	int	      retcode;

	DRM_DEBUG("fd = %d, device = 0x%x\n", fd, dev->device);
	retcode = fasync_helper(fd, filp, on, &dev->buf_async);
	if (retcode < 0) return retcode;
	return 0;
}


/* The drm_read and drm_write_string code (especially that which manages
   the circular buffer), is based on Alessandro Rubini's LINUX DEVICE
   DRIVERS (Cambridge: O'Reilly, 1998), pages 111-113. */

ssize_t DRM(read)(struct file *filp, char *buf, size_t count, loff_t *off)
{
	drm_file_t    *priv   = filp->private_data;
	drm_device_t  *dev    = priv->dev;
	int	      left;
	int	      avail;
	int	      send;
	int	      cur;

	DRM_DEBUG("%p, %p\n", dev->buf_rp, dev->buf_wp);

	while (dev->buf_rp == dev->buf_wp) {
		DRM_DEBUG("  sleeping\n");
		if (filp->f_flags & O_NONBLOCK) {
			return -EAGAIN;
		}
		interruptible_sleep_on(&dev->buf_readers);
		if (signal_pending(current)) {
			DRM_DEBUG("  interrupted\n");
			return -ERESTARTSYS;
		}
		DRM_DEBUG("  awake\n");
	}

	left  = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
	avail = DRM_BSZ - left;
	send  = DRM_MIN(avail, count);

	while (send) {
		if (dev->buf_wp > dev->buf_rp) {
			cur = DRM_MIN(send, dev->buf_wp - dev->buf_rp);
		} else {
			cur = DRM_MIN(send, dev->buf_end - dev->buf_rp);
		}
		if (copy_to_user(buf, dev->buf_rp, cur))
			return -EFAULT;
		dev->buf_rp += cur;
		if (dev->buf_rp == dev->buf_end) dev->buf_rp = dev->buf;
		send -= cur;
	}

	wake_up_interruptible(&dev->buf_writers);
	return DRM_MIN(avail, count);;
}

int DRM(write_string)(drm_device_t *dev, const char *s)
{
	int left   = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
	int send   = strlen(s);
	int count;

	DRM_DEBUG("%d left, %d to send (%p, %p)\n",
		  left, send, dev->buf_rp, dev->buf_wp);

	if (left == 1 || dev->buf_wp != dev->buf_rp) {
		DRM_ERROR("Buffer not empty (%d left, wp = %p, rp = %p)\n",
			  left,
			  dev->buf_wp,
			  dev->buf_rp);
	}

	while (send) {
		if (dev->buf_wp >= dev->buf_rp) {
			count = DRM_MIN(send, dev->buf_end - dev->buf_wp);
			if (count == left) --count; /* Leave a hole */
		} else {
			count = DRM_MIN(send, dev->buf_rp - dev->buf_wp - 1);
		}
		strncpy(dev->buf_wp, s, count);
		dev->buf_wp += count;
		if (dev->buf_wp == dev->buf_end) dev->buf_wp = dev->buf;
		send -= count;
	}

#if LINUX_VERSION_CODE < 0x020315 && !defined(KILLFASYNCHASTHREEPARAMETERS)
	/* The extra parameter to kill_fasync was added in 2.3.21, and is
           _not_ present in _stock_ 2.2.14 and 2.2.15.  However, some
           distributions patch 2.2.x kernels to add this parameter.  The
           Makefile.linux attempts to detect this addition and defines
           KILLFASYNCHASTHREEPARAMETERS if three parameters are found. */
	if (dev->buf_async) kill_fasync(dev->buf_async, SIGIO);
#else

				/* Parameter added in 2.3.21. */
#if LINUX_VERSION_CODE < 0x020400
	if (dev->buf_async) kill_fasync(dev->buf_async, SIGIO, POLL_IN);
#else
				/* Type of first parameter changed in
                                   Linux 2.4.0-test2... */
	if (dev->buf_async) kill_fasync(&dev->buf_async, SIGIO, POLL_IN);
#endif
#endif
	DRM_DEBUG("waking\n");
	wake_up_interruptible(&dev->buf_readers);
	return 0;
}

unsigned int DRM(poll)(struct file *filp, struct poll_table_struct *wait)
{
	drm_file_t   *priv = filp->private_data;
	drm_device_t *dev  = priv->dev;

	poll_wait(filp, &dev->buf_readers, wait);
	if (dev->buf_wp != dev->buf_rp) return POLLIN | POLLRDNORM;
	return 0;
}