1 /*	$NetBSD: vbox_irq.c,v 1.2 2021/12/18 23:45:44 riastradh Exp $	*/
2 
3 // SPDX-License-Identifier: MIT
4 /*
5  * Copyright (C) 2016-2017 Oracle Corporation
6  * This file is based on qxl_irq.c
7  * Copyright 2013 Red Hat Inc.
8  * Authors: Dave Airlie
9  *          Alon Levy
10  *          Michael Thayer <michael.thayer@oracle.com,
11  *          Hans de Goede <hdegoede@redhat.com>
12  */
13 
14 #include <sys/cdefs.h>
15 __KERNEL_RCSID(0, "$NetBSD: vbox_irq.c,v 1.2 2021/12/18 23:45:44 riastradh Exp $");
16 
17 #include <linux/pci.h>
18 #include <drm/drm_irq.h>
19 #include <drm/drm_probe_helper.h>
20 
21 #include "vbox_drv.h"
22 #include "vboxvideo.h"
23 
vbox_clear_irq(void)24 static void vbox_clear_irq(void)
25 {
26 	outl((u32)~0, VGA_PORT_HGSMI_HOST);
27 }
28 
vbox_get_flags(struct vbox_private * vbox)29 static u32 vbox_get_flags(struct vbox_private *vbox)
30 {
31 	return readl(vbox->guest_heap + HOST_FLAGS_OFFSET);
32 }
33 
vbox_report_hotplug(struct vbox_private * vbox)34 void vbox_report_hotplug(struct vbox_private *vbox)
35 {
36 	schedule_work(&vbox->hotplug_work);
37 }
38 
vbox_irq_handler(int irq,void * arg)39 irqreturn_t vbox_irq_handler(int irq, void *arg)
40 {
41 	struct drm_device *dev = (struct drm_device *)arg;
42 	struct vbox_private *vbox = (struct vbox_private *)dev->dev_private;
43 	u32 host_flags = vbox_get_flags(vbox);
44 
45 	if (!(host_flags & HGSMIHOSTFLAGS_IRQ))
46 		return IRQ_NONE;
47 
48 	/*
49 	 * Due to a bug in the initial host implementation of hot-plug irqs,
50 	 * the hot-plug and cursor capability flags were never cleared.
51 	 * Fortunately we can tell when they would have been set by checking
52 	 * that the VSYNC flag is not set.
53 	 */
54 	if (host_flags &
55 	    (HGSMIHOSTFLAGS_HOTPLUG | HGSMIHOSTFLAGS_CURSOR_CAPABILITIES) &&
56 	    !(host_flags & HGSMIHOSTFLAGS_VSYNC))
57 		vbox_report_hotplug(vbox);
58 
59 	vbox_clear_irq();
60 
61 	return IRQ_HANDLED;
62 }
63 
64 /*
65  * Check that the position hints provided by the host are suitable for GNOME
66  * shell (i.e. all screens disjoint and hints for all enabled screens) and if
67  * not replace them with default ones.  Providing valid hints improves the
68  * chances that we will get a known screen layout for pointer mapping.
69  */
validate_or_set_position_hints(struct vbox_private * vbox)70 static void validate_or_set_position_hints(struct vbox_private *vbox)
71 {
72 	struct vbva_modehint *hintsi, *hintsj;
73 	bool valid = true;
74 	u16 currentx = 0;
75 	int i, j;
76 
77 	for (i = 0; i < vbox->num_crtcs; ++i) {
78 		for (j = 0; j < i; ++j) {
79 			hintsi = &vbox->last_mode_hints[i];
80 			hintsj = &vbox->last_mode_hints[j];
81 
82 			if (hintsi->enabled && hintsj->enabled) {
83 				if (hintsi->dx >= 0xffff ||
84 				    hintsi->dy >= 0xffff ||
85 				    hintsj->dx >= 0xffff ||
86 				    hintsj->dy >= 0xffff ||
87 				    (hintsi->dx <
88 					hintsj->dx + (hintsj->cx & 0x8fff) &&
89 				     hintsi->dx + (hintsi->cx & 0x8fff) >
90 					hintsj->dx) ||
91 				    (hintsi->dy <
92 					hintsj->dy + (hintsj->cy & 0x8fff) &&
93 				     hintsi->dy + (hintsi->cy & 0x8fff) >
94 					hintsj->dy))
95 					valid = false;
96 			}
97 		}
98 	}
99 	if (!valid)
100 		for (i = 0; i < vbox->num_crtcs; ++i) {
101 			if (vbox->last_mode_hints[i].enabled) {
102 				vbox->last_mode_hints[i].dx = currentx;
103 				vbox->last_mode_hints[i].dy = 0;
104 				currentx +=
105 				    vbox->last_mode_hints[i].cx & 0x8fff;
106 			}
107 		}
108 }
109 
110 /* Query the host for the most recent video mode hints. */
vbox_update_mode_hints(struct vbox_private * vbox)111 static void vbox_update_mode_hints(struct vbox_private *vbox)
112 {
113 	struct drm_connector_list_iter conn_iter;
114 	struct drm_device *dev = &vbox->ddev;
115 	struct drm_connector *connector;
116 	struct vbox_connector *vbox_conn;
117 	struct vbva_modehint *hints;
118 	u16 flags;
119 	bool disconnected;
120 	unsigned int crtc_id;
121 	int ret;
122 
123 	ret = hgsmi_get_mode_hints(vbox->guest_pool, vbox->num_crtcs,
124 				   vbox->last_mode_hints);
125 	if (ret) {
126 		DRM_ERROR("vboxvideo: hgsmi_get_mode_hints failed: %d\n", ret);
127 		return;
128 	}
129 
130 	validate_or_set_position_hints(vbox);
131 
132 	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
133 	drm_connector_list_iter_begin(dev, &conn_iter);
134 	drm_for_each_connector_iter(connector, &conn_iter) {
135 		vbox_conn = to_vbox_connector(connector);
136 
137 		hints = &vbox->last_mode_hints[vbox_conn->vbox_crtc->crtc_id];
138 		if (hints->magic != VBVAMODEHINT_MAGIC)
139 			continue;
140 
141 		disconnected = !(hints->enabled);
142 		crtc_id = vbox_conn->vbox_crtc->crtc_id;
143 		vbox_conn->mode_hint.width = hints->cx;
144 		vbox_conn->mode_hint.height = hints->cy;
145 		vbox_conn->vbox_crtc->x_hint = hints->dx;
146 		vbox_conn->vbox_crtc->y_hint = hints->dy;
147 		vbox_conn->mode_hint.disconnected = disconnected;
148 
149 		if (vbox_conn->vbox_crtc->disconnected == disconnected)
150 			continue;
151 
152 		if (disconnected)
153 			flags = VBVA_SCREEN_F_ACTIVE | VBVA_SCREEN_F_DISABLED;
154 		else
155 			flags = VBVA_SCREEN_F_ACTIVE | VBVA_SCREEN_F_BLANK;
156 
157 		hgsmi_process_display_info(vbox->guest_pool, crtc_id, 0, 0, 0,
158 					   hints->cx * 4, hints->cx,
159 					   hints->cy, 0, flags);
160 
161 		vbox_conn->vbox_crtc->disconnected = disconnected;
162 	}
163 	drm_connector_list_iter_end(&conn_iter);
164 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
165 }
166 
vbox_hotplug_worker(struct work_struct * work)167 static void vbox_hotplug_worker(struct work_struct *work)
168 {
169 	struct vbox_private *vbox = container_of(work, struct vbox_private,
170 						 hotplug_work);
171 
172 	vbox_update_mode_hints(vbox);
173 	drm_kms_helper_hotplug_event(&vbox->ddev);
174 }
175 
vbox_irq_init(struct vbox_private * vbox)176 int vbox_irq_init(struct vbox_private *vbox)
177 {
178 	INIT_WORK(&vbox->hotplug_work, vbox_hotplug_worker);
179 	vbox_update_mode_hints(vbox);
180 
181 	return drm_irq_install(&vbox->ddev, vbox->ddev.pdev->irq);
182 }
183 
vbox_irq_fini(struct vbox_private * vbox)184 void vbox_irq_fini(struct vbox_private *vbox)
185 {
186 	drm_irq_uninstall(&vbox->ddev);
187 	flush_work(&vbox->hotplug_work);
188 }
189