xref: /freebsd/sys/dev/xen/xenpci/xenpci.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2008 Citrix Systems, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 #include <sys/param.h>
31 #include <sys/bus.h>
32 #include <sys/kernel.h>
33 #include <sys/malloc.h>
34 #include <sys/module.h>
35 
36 #include <machine/bus.h>
37 #include <machine/resource.h>
38 #include <sys/rman.h>
39 
40 #include <machine/stdarg.h>
41 
42 #include <xen/xen-os.h>
43 #include <xen/features.h>
44 #include <xen/hypervisor.h>
45 #include <xen/hvm.h>
46 #include <xen/xen_intr.h>
47 
48 #include <dev/pci/pcireg.h>
49 #include <dev/pci/pcivar.h>
50 
51 #include <dev/xen/xenpci/xenpcivar.h>
52 
53 static int
54 xenpci_irq_init(device_t device, struct xenpci_softc *scp)
55 {
56 	int error;
57 
58 	error = BUS_SETUP_INTR(device_get_parent(device), device,
59 			       scp->res_irq, INTR_MPSAFE|INTR_TYPE_MISC,
60 			       xen_intr_handle_upcall, NULL, NULL,
61 			       &scp->intr_cookie);
62 	if (error)
63 		return error;
64 
65 #ifdef SMP
66 	/*
67 	 * When using the PCI event delivery callback we cannot assign
68 	 * events to specific vCPUs, so all events are delivered to vCPU#0 by
69 	 * Xen. Since the PCI interrupt can fire on any CPU by default, we
70 	 * need to bind it to vCPU#0 in order to ensure that
71 	 * xen_intr_handle_upcall always gets called on vCPU#0.
72 	 */
73 	error = BUS_BIND_INTR(device_get_parent(device), device,
74 	                      scp->res_irq, 0);
75 	if (error)
76 		return error;
77 #endif
78 
79 	xen_hvm_set_callback(device);
80 	return (0);
81 }
82 
83 /*
84  * Deallocate anything allocated by xenpci_allocate_resources.
85  */
86 static int
87 xenpci_deallocate_resources(device_t dev)
88 {
89 	struct xenpci_softc *scp = device_get_softc(dev);
90 
91 	if (scp->res_irq != 0) {
92 		bus_deactivate_resource(dev, SYS_RES_IRQ,
93 			scp->rid_irq, scp->res_irq);
94 		bus_release_resource(dev, SYS_RES_IRQ,
95 			scp->rid_irq, scp->res_irq);
96 		scp->res_irq = 0;
97 	}
98 
99 	return (0);
100 }
101 
102 /*
103  * Allocate irq and memory resources.
104  */
105 static int
106 xenpci_allocate_resources(device_t dev)
107 {
108 	struct xenpci_softc *scp = device_get_softc(dev);
109 
110 	scp->res_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ,
111 			&scp->rid_irq, RF_SHAREABLE|RF_ACTIVE);
112 	if (scp->res_irq == NULL) {
113 		printf("xenpci Could not allocate irq.\n");
114 		goto errexit;
115 	}
116 
117 	return (0);
118 
119 errexit:
120 	/* Cleanup anything we may have assigned. */
121 	xenpci_deallocate_resources(dev);
122 	return (ENXIO); /* For want of a better idea. */
123 }
124 
125 /*
126  * Probe - just check device ID.
127  */
128 static int
129 xenpci_probe(device_t dev)
130 {
131 
132 	if (pci_get_devid(dev) != 0x00015853)
133 		return (ENXIO);
134 
135 	device_set_desc(dev, "Xen Platform Device");
136 	return (BUS_PROBE_DEFAULT);
137 }
138 
139 /*
140  * Attach - find resources and talk to Xen.
141  */
142 static int
143 xenpci_attach(device_t dev)
144 {
145 	struct xenpci_softc *scp = device_get_softc(dev);
146 	int error;
147 
148 	error = xenpci_allocate_resources(dev);
149 	if (error) {
150 		device_printf(dev, "xenpci_allocate_resources failed(%d).\n",
151 		    error);
152 		goto errexit;
153 	}
154 
155 	/*
156 	 * Hook the irq up to evtchn
157 	 */
158 	error = xenpci_irq_init(dev, scp);
159 	if (error) {
160 		device_printf(dev, "xenpci_irq_init failed(%d).\n",
161 			error);
162 		goto errexit;
163 	}
164 
165 	return (0);
166 
167 errexit:
168 	/*
169 	 * Undo anything we may have done.
170 	 */
171 	xenpci_deallocate_resources(dev);
172 	return (error);
173 }
174 
175 /*
176  * Detach - reverse anything done by attach.
177  */
178 static int
179 xenpci_detach(device_t dev)
180 {
181 	struct xenpci_softc *scp = device_get_softc(dev);
182 	device_t parent = device_get_parent(dev);
183 
184 	/*
185 	 * Take our interrupt handler out of the list of handlers
186 	 * that can handle this irq.
187 	 */
188 	if (scp->intr_cookie != NULL) {
189 		if (BUS_TEARDOWN_INTR(parent, dev,
190 		    scp->res_irq, scp->intr_cookie) != 0)
191 			device_printf(dev,
192 			    "intr teardown failed.. continuing\n");
193 		scp->intr_cookie = NULL;
194 	}
195 
196 	/*
197 	 * Deallocate any system resources we may have
198 	 * allocated on behalf of this driver.
199 	 */
200 	return (xenpci_deallocate_resources(dev));
201 }
202 
203 static int
204 xenpci_resume(device_t dev)
205 {
206 	xen_hvm_set_callback(dev);
207 	return (0);
208 }
209 
210 static device_method_t xenpci_methods[] = {
211 	/* Device interface */
212 	DEVMETHOD(device_probe,		xenpci_probe),
213 	DEVMETHOD(device_attach,	xenpci_attach),
214 	DEVMETHOD(device_detach,	xenpci_detach),
215 	DEVMETHOD(device_resume,	xenpci_resume),
216 	{ 0, 0 }
217 };
218 
219 static driver_t xenpci_driver = {
220 	"xenpci",
221 	xenpci_methods,
222 	sizeof(struct xenpci_softc),
223 };
224 
225 DRIVER_MODULE(xenpci, pci, xenpci_driver, 0, 0);
226