1 /*
2  * drm_irq.c IRQ and vblank support
3  *
4  * \author Rickard E. (Rik) Faith <faith@valinux.com>
5  * \author Gareth Hughes <gareth@valinux.com>
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a
8  * copy of this software and associated documentation files (the "Software"),
9  * to deal in the Software without restriction, including without limitation
10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11  * and/or sell copies of the Software, and to permit persons to whom the
12  * Software is furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the next
15  * paragraph) shall be included in all copies or substantial portions of the
16  * Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
21  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
22  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
23  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
24  * OTHER DEALINGS IN THE SOFTWARE.
25  */
26 
27 /*
28  * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
29  *
30  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
31  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
32  * All Rights Reserved.
33  *
34  * Permission is hereby granted, free of charge, to any person obtaining a
35  * copy of this software and associated documentation files (the "Software"),
36  * to deal in the Software without restriction, including without limitation
37  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
38  * and/or sell copies of the Software, and to permit persons to whom the
39  * Software is furnished to do so, subject to the following conditions:
40  *
41  * The above copyright notice and this permission notice (including the next
42  * paragraph) shall be included in all copies or substantial portions of the
43  * Software.
44  *
45  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
46  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
47  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
48  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
49  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
50  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
51  * OTHER DEALINGS IN THE SOFTWARE.
52  */
53 
54 
55 #include <linux/export.h>
56 #include <linux/interrupt.h>	/* For task queue support */
57 #include <linux/pci.h>
58 #include <linux/vgaarb.h>
59 
60 #include <drm/drm.h>
61 #include <drm/drm_device.h>
62 #include <drm/drm_drv.h>
63 #include <drm/drm_legacy.h>
64 #include <drm/drm_print.h>
65 #include <drm/drm_vblank.h>
66 
67 #include "drm_internal.h"
68 
drm_legacy_irq_install(struct drm_device * dev,int irq)69 static int drm_legacy_irq_install(struct drm_device *dev, int irq)
70 {
71 	int ret;
72 	unsigned long sh_flags = 0;
73 
74 	if (irq == 0)
75 		return -EINVAL;
76 
77 	if (dev->irq_enabled)
78 		return -EBUSY;
79 	dev->irq_enabled = true;
80 
81 	DRM_DEBUG("irq=%d\n", irq);
82 
83 	/* Before installing handler */
84 	if (dev->driver->irq_preinstall)
85 		dev->driver->irq_preinstall(dev);
86 
87 	/* PCI devices require shared interrupts. */
88 	if (dev_is_pci(dev->dev))
89 		sh_flags = IRQF_SHARED;
90 
91 	ret = request_irq(irq, dev->driver->irq_handler,
92 			  sh_flags, dev->driver->name, dev);
93 
94 	if (ret < 0) {
95 		dev->irq_enabled = false;
96 		return ret;
97 	}
98 
99 	/* After installing handler */
100 	if (dev->driver->irq_postinstall)
101 		ret = dev->driver->irq_postinstall(dev);
102 
103 	if (ret < 0) {
104 		dev->irq_enabled = false;
105 		if (drm_core_check_feature(dev, DRIVER_LEGACY))
106 			vga_client_unregister(to_pci_dev(dev->dev));
107 		free_irq(irq, dev);
108 	} else {
109 		dev->irq = irq;
110 	}
111 
112 	return ret;
113 }
114 
drm_legacy_irq_uninstall(struct drm_device * dev)115 int drm_legacy_irq_uninstall(struct drm_device *dev)
116 {
117 	unsigned long irqflags;
118 	bool irq_enabled;
119 	int i;
120 
121 	irq_enabled = dev->irq_enabled;
122 	dev->irq_enabled = false;
123 
124 	/*
125 	 * Wake up any waiters so they don't hang. This is just to paper over
126 	 * issues for UMS drivers which aren't in full control of their
127 	 * vblank/irq handling. KMS drivers must ensure that vblanks are all
128 	 * disabled when uninstalling the irq handler.
129 	 */
130 	if (drm_dev_has_vblank(dev)) {
131 		spin_lock_irqsave(&dev->vbl_lock, irqflags);
132 		for (i = 0; i < dev->num_crtcs; i++) {
133 			struct drm_vblank_crtc *vblank = &dev->vblank[i];
134 
135 			if (!vblank->enabled)
136 				continue;
137 
138 			WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
139 
140 			drm_vblank_disable_and_save(dev, i);
141 			wake_up(&vblank->queue);
142 		}
143 		spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
144 	}
145 
146 	if (!irq_enabled)
147 		return -EINVAL;
148 
149 	DRM_DEBUG("irq=%d\n", dev->irq);
150 
151 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
152 		vga_client_unregister(to_pci_dev(dev->dev));
153 
154 	if (dev->driver->irq_uninstall)
155 		dev->driver->irq_uninstall(dev);
156 
157 	free_irq(dev->irq, dev);
158 
159 	return 0;
160 }
161 EXPORT_SYMBOL(drm_legacy_irq_uninstall);
162 
drm_legacy_irq_control(struct drm_device * dev,void * data,struct drm_file * file_priv)163 int drm_legacy_irq_control(struct drm_device *dev, void *data,
164 			   struct drm_file *file_priv)
165 {
166 	struct drm_control *ctl = data;
167 	int ret = 0, irq;
168 	struct pci_dev *pdev;
169 
170 	/* if we haven't irq we fallback for compatibility reasons -
171 	 * this used to be a separate function in drm_dma.h
172 	 */
173 
174 	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
175 		return 0;
176 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
177 		return 0;
178 	/* UMS was only ever supported on pci devices. */
179 	if (WARN_ON(!dev_is_pci(dev->dev)))
180 		return -EINVAL;
181 
182 	switch (ctl->func) {
183 	case DRM_INST_HANDLER:
184 		pdev = to_pci_dev(dev->dev);
185 		irq = pdev->irq;
186 
187 		if (dev->if_version < DRM_IF_VERSION(1, 2) &&
188 		    ctl->irq != irq)
189 			return -EINVAL;
190 		mutex_lock(&dev->struct_mutex);
191 		ret = drm_legacy_irq_install(dev, irq);
192 		mutex_unlock(&dev->struct_mutex);
193 
194 		return ret;
195 	case DRM_UNINST_HANDLER:
196 		mutex_lock(&dev->struct_mutex);
197 		ret = drm_legacy_irq_uninstall(dev);
198 		mutex_unlock(&dev->struct_mutex);
199 
200 		return ret;
201 	default:
202 		return -EINVAL;
203 	}
204 }
205