drm_fops.c revision d1794f2c5b5817eb79ccc5e00701ca748d1b073a
1/**
2 * \file drm_fops.c
3 * File operations for DRM
4 *
5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Daryll Strauss <daryll@valinux.com>
7 * \author Gareth Hughes <gareth@valinux.com>
8 */
9
10/*
11 * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
12 *
13 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
14 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
15 * All Rights Reserved.
16 *
17 * Permission is hereby granted, free of charge, to any person obtaining a
18 * copy of this software and associated documentation files (the "Software"),
19 * to deal in the Software without restriction, including without limitation
20 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
21 * and/or sell copies of the Software, and to permit persons to whom the
22 * Software is furnished to do so, subject to the following conditions:
23 *
24 * The above copyright notice and this permission notice (including the next
25 * paragraph) shall be included in all copies or substantial portions of the
26 * Software.
27 *
28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
29 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
30 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
31 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
32 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
33 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
34 * OTHER DEALINGS IN THE SOFTWARE.
35 */
36
37#include "drmP.h"
38#include "drm_sarea.h"
39#include <linux/poll.h>
40#include <linux/smp_lock.h>
41
42static int drm_open_helper(struct inode *inode, struct file *filp,
43			   struct drm_device * dev);
44
45static int drm_setup(struct drm_device * dev)
46{
47	drm_local_map_t *map;
48	int i;
49	int ret;
50	u32 sareapage;
51
52	if (dev->driver->firstopen) {
53		ret = dev->driver->firstopen(dev);
54		if (ret != 0)
55			return ret;
56	}
57
58	dev->magicfree.next = NULL;
59
60	/* prebuild the SAREA */
61	sareapage = max_t(unsigned, SAREA_MAX, PAGE_SIZE);
62	i = drm_addmap(dev, 0, sareapage, _DRM_SHM, _DRM_CONTAINS_LOCK, &map);
63	if (i != 0)
64		return i;
65
66	atomic_set(&dev->ioctl_count, 0);
67	atomic_set(&dev->vma_count, 0);
68	dev->buf_use = 0;
69	atomic_set(&dev->buf_alloc, 0);
70
71	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
72		i = drm_dma_setup(dev);
73		if (i < 0)
74			return i;
75	}
76
77	for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
78		atomic_set(&dev->counts[i], 0);
79
80	drm_ht_create(&dev->magiclist, DRM_MAGIC_HASH_ORDER);
81	INIT_LIST_HEAD(&dev->magicfree);
82
83	dev->sigdata.lock = NULL;
84	init_waitqueue_head(&dev->lock.lock_queue);
85	dev->queue_count = 0;
86	dev->queue_reserved = 0;
87	dev->queue_slots = 0;
88	dev->queuelist = NULL;
89	dev->irq_enabled = 0;
90	dev->context_flag = 0;
91	dev->interrupt_flag = 0;
92	dev->dma_flag = 0;
93	dev->last_context = 0;
94	dev->last_switch = 0;
95	dev->last_checked = 0;
96	init_waitqueue_head(&dev->context_wait);
97	dev->if_version = 0;
98
99	dev->ctx_start = 0;
100	dev->lck_start = 0;
101
102	dev->buf_async = NULL;
103	init_waitqueue_head(&dev->buf_readers);
104	init_waitqueue_head(&dev->buf_writers);
105
106	DRM_DEBUG("\n");
107
108	/*
109	 * The kernel's context could be created here, but is now created
110	 * in drm_dma_enqueue.  This is more resource-efficient for
111	 * hardware that does not do DMA, but may mean that
112	 * drm_select_queue fails between the time the interrupt is
113	 * initialized and the time the queues are initialized.
114	 */
115
116	return 0;
117}
118
119/**
120 * Open file.
121 *
122 * \param inode device inode
123 * \param filp file pointer.
124 * \return zero on success or a negative number on failure.
125 *
126 * Searches the DRM device with the same minor number, calls open_helper(), and
127 * increments the device open count. If the open count was previous at zero,
128 * i.e., it's the first that the device is open, then calls setup().
129 */
130int drm_open(struct inode *inode, struct file *filp)
131{
132	struct drm_device *dev = NULL;
133	int minor_id = iminor(inode);
134	struct drm_minor *minor;
135	int retcode = 0;
136
137	minor = idr_find(&drm_minors_idr, minor_id);
138	if (!minor)
139		return -ENODEV;
140
141	if (!(dev = minor->dev))
142		return -ENODEV;
143
144	retcode = drm_open_helper(inode, filp, dev);
145	if (!retcode) {
146		atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
147		spin_lock(&dev->count_lock);
148		if (!dev->open_count++) {
149			spin_unlock(&dev->count_lock);
150			return drm_setup(dev);
151		}
152		spin_unlock(&dev->count_lock);
153	}
154
155	return retcode;
156}
157EXPORT_SYMBOL(drm_open);
158
159/**
160 * File \c open operation.
161 *
162 * \param inode device inode.
163 * \param filp file pointer.
164 *
165 * Puts the dev->fops corresponding to the device minor number into
166 * \p filp, call the \c open method, and restore the file operations.
167 */
168int drm_stub_open(struct inode *inode, struct file *filp)
169{
170	struct drm_device *dev = NULL;
171	struct drm_minor *minor;
172	int minor_id = iminor(inode);
173	int err = -ENODEV;
174	const struct file_operations *old_fops;
175
176	DRM_DEBUG("\n");
177
178	/* BKL pushdown: note that nothing else serializes idr_find() */
179	lock_kernel();
180	minor = idr_find(&drm_minors_idr, minor_id);
181	if (!minor)
182		goto out;
183
184	if (!(dev = minor->dev))
185		goto out;
186
187	old_fops = filp->f_op;
188	filp->f_op = fops_get(&dev->driver->fops);
189	if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
190		fops_put(filp->f_op);
191		filp->f_op = fops_get(old_fops);
192	}
193	fops_put(old_fops);
194
195out:
196	unlock_kernel();
197	return err;
198}
199
200/**
201 * Check whether DRI will run on this CPU.
202 *
203 * \return non-zero if the DRI will run on this CPU, or zero otherwise.
204 */
205static int drm_cpu_valid(void)
206{
207#if defined(__i386__)
208	if (boot_cpu_data.x86 == 3)
209		return 0;	/* No cmpxchg on a 386 */
210#endif
211#if defined(__sparc__) && !defined(__sparc_v9__)
212	return 0;		/* No cmpxchg before v9 sparc. */
213#endif
214	return 1;
215}
216
217/**
218 * Called whenever a process opens /dev/drm.
219 *
220 * \param inode device inode.
221 * \param filp file pointer.
222 * \param dev device.
223 * \return zero on success or a negative number on failure.
224 *
225 * Creates and initializes a drm_file structure for the file private data in \p
226 * filp and add it into the double linked list in \p dev.
227 */
228static int drm_open_helper(struct inode *inode, struct file *filp,
229			   struct drm_device * dev)
230{
231	int minor_id = iminor(inode);
232	struct drm_file *priv;
233	int ret;
234
235	if (filp->f_flags & O_EXCL)
236		return -EBUSY;	/* No exclusive opens */
237	if (!drm_cpu_valid())
238		return -EINVAL;
239
240	DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
241
242	priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
243	if (!priv)
244		return -ENOMEM;
245
246	memset(priv, 0, sizeof(*priv));
247	filp->private_data = priv;
248	priv->filp = filp;
249	priv->uid = current->euid;
250	priv->pid = task_pid_nr(current);
251	priv->minor = idr_find(&drm_minors_idr, minor_id);
252	priv->ioctl_count = 0;
253	/* for compatibility root is always authenticated */
254	priv->authenticated = capable(CAP_SYS_ADMIN);
255	priv->lock_count = 0;
256
257	INIT_LIST_HEAD(&priv->lhead);
258
259	if (dev->driver->open) {
260		ret = dev->driver->open(dev, priv);
261		if (ret < 0)
262			goto out_free;
263	}
264
265	mutex_lock(&dev->struct_mutex);
266	if (list_empty(&dev->filelist))
267		priv->master = 1;
268
269	list_add(&priv->lhead, &dev->filelist);
270	mutex_unlock(&dev->struct_mutex);
271
272#ifdef __alpha__
273	/*
274	 * Default the hose
275	 */
276	if (!dev->hose) {
277		struct pci_dev *pci_dev;
278		pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
279		if (pci_dev) {
280			dev->hose = pci_dev->sysdata;
281			pci_dev_put(pci_dev);
282		}
283		if (!dev->hose) {
284			struct pci_bus *b = pci_bus_b(pci_root_buses.next);
285			if (b)
286				dev->hose = b->sysdata;
287		}
288	}
289#endif
290
291	return 0;
292      out_free:
293	drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
294	filp->private_data = NULL;
295	return ret;
296}
297
298/** No-op. */
299int drm_fasync(int fd, struct file *filp, int on)
300{
301	struct drm_file *priv = filp->private_data;
302	struct drm_device *dev = priv->minor->dev;
303	int retcode;
304
305	DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
306		  (long)old_encode_dev(priv->minor->device));
307	retcode = fasync_helper(fd, filp, on, &dev->buf_async);
308	if (retcode < 0)
309		return retcode;
310	return 0;
311}
312EXPORT_SYMBOL(drm_fasync);
313
314/**
315 * Release file.
316 *
317 * \param inode device inode
318 * \param file_priv DRM file private.
319 * \return zero on success or a negative number on failure.
320 *
321 * If the hardware lock is held then free it, and take it again for the kernel
322 * context since it's necessary to reclaim buffers. Unlink the file private
323 * data from its list and free it. Decreases the open count and if it reaches
324 * zero calls drm_lastclose().
325 */
326int drm_release(struct inode *inode, struct file *filp)
327{
328	struct drm_file *file_priv = filp->private_data;
329	struct drm_device *dev = file_priv->minor->dev;
330	int retcode = 0;
331
332	lock_kernel();
333
334	DRM_DEBUG("open_count = %d\n", dev->open_count);
335
336	if (dev->driver->preclose)
337		dev->driver->preclose(dev, file_priv);
338
339	/* ========================================================
340	 * Begin inline drm_release
341	 */
342
343	DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
344		  task_pid_nr(current),
345		  (long)old_encode_dev(file_priv->minor->device),
346		  dev->open_count);
347
348	if (dev->driver->reclaim_buffers_locked && dev->lock.hw_lock) {
349		if (drm_i_have_hw_lock(dev, file_priv)) {
350			dev->driver->reclaim_buffers_locked(dev, file_priv);
351		} else {
352			unsigned long endtime = jiffies + 3 * DRM_HZ;
353			int locked = 0;
354
355			drm_idlelock_take(&dev->lock);
356
357			/*
358			 * Wait for a while.
359			 */
360
361			do{
362				spin_lock_bh(&dev->lock.spinlock);
363				locked = dev->lock.idle_has_lock;
364				spin_unlock_bh(&dev->lock.spinlock);
365				if (locked)
366					break;
367				schedule();
368			} while (!time_after_eq(jiffies, endtime));
369
370			if (!locked) {
371				DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
372					  "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
373					  "\tI will go on reclaiming the buffers anyway.\n");
374			}
375
376			dev->driver->reclaim_buffers_locked(dev, file_priv);
377			drm_idlelock_release(&dev->lock);
378		}
379	}
380
381	if (dev->driver->reclaim_buffers_idlelocked && dev->lock.hw_lock) {
382
383		drm_idlelock_take(&dev->lock);
384		dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
385		drm_idlelock_release(&dev->lock);
386
387	}
388
389	if (drm_i_have_hw_lock(dev, file_priv)) {
390		DRM_DEBUG("File %p released, freeing lock for context %d\n",
391			  filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
392
393		drm_lock_free(&dev->lock,
394			      _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
395	}
396
397
398	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
399	    !dev->driver->reclaim_buffers_locked) {
400		dev->driver->reclaim_buffers(dev, file_priv);
401	}
402
403	drm_fasync(-1, filp, 0);
404
405	mutex_lock(&dev->ctxlist_mutex);
406	if (!list_empty(&dev->ctxlist)) {
407		struct drm_ctx_list *pos, *n;
408
409		list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
410			if (pos->tag == file_priv &&
411			    pos->handle != DRM_KERNEL_CONTEXT) {
412				if (dev->driver->context_dtor)
413					dev->driver->context_dtor(dev,
414								  pos->handle);
415
416				drm_ctxbitmap_free(dev, pos->handle);
417
418				list_del(&pos->head);
419				drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
420				--dev->ctx_count;
421			}
422		}
423	}
424	mutex_unlock(&dev->ctxlist_mutex);
425
426	mutex_lock(&dev->struct_mutex);
427	if (file_priv->remove_auth_on_close == 1) {
428		struct drm_file *temp;
429
430		list_for_each_entry(temp, &dev->filelist, lhead)
431			temp->authenticated = 0;
432	}
433	list_del(&file_priv->lhead);
434	mutex_unlock(&dev->struct_mutex);
435
436	if (dev->driver->postclose)
437		dev->driver->postclose(dev, file_priv);
438	drm_free(file_priv, sizeof(*file_priv), DRM_MEM_FILES);
439
440	/* ========================================================
441	 * End inline drm_release
442	 */
443
444	atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
445	spin_lock(&dev->count_lock);
446	if (!--dev->open_count) {
447		if (atomic_read(&dev->ioctl_count) || dev->blocked) {
448			DRM_ERROR("Device busy: %d %d\n",
449				  atomic_read(&dev->ioctl_count), dev->blocked);
450			spin_unlock(&dev->count_lock);
451			unlock_kernel();
452			return -EBUSY;
453		}
454		spin_unlock(&dev->count_lock);
455		unlock_kernel();
456		return drm_lastclose(dev);
457	}
458	spin_unlock(&dev->count_lock);
459
460	unlock_kernel();
461
462	return retcode;
463}
464EXPORT_SYMBOL(drm_release);
465
466/** No-op. */
467unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
468{
469	return 0;
470}
471EXPORT_SYMBOL(drm_poll);
472