xref: /freebsd/sys/dev/xen/xenpci/xenpci.c (revision a5d8944a83ff8a3aad14197b7aa0800ff9bda95e)
1 /*
2  * Copyright (c) 2008 Citrix Systems, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
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 /*
54  * This is used to find our platform device instance.
55  */
56 static devclass_t xenpci_devclass;
57 
58 static int
59 xenpci_intr_filter(void *trap_frame)
60 {
61 	xen_intr_handle_upcall(trap_frame);
62 	return (FILTER_HANDLED);
63 }
64 
65 static int
66 xenpci_irq_init(device_t device, struct xenpci_softc *scp)
67 {
68 	int error;
69 
70 	error = BUS_SETUP_INTR(device_get_parent(device), device,
71 			       scp->res_irq, INTR_MPSAFE|INTR_TYPE_MISC,
72 			       xenpci_intr_filter, NULL, /*trap_frame*/NULL,
73 			       &scp->intr_cookie);
74 	if (error)
75 		return error;
76 
77 #ifdef SMP
78 	/*
79 	 * When using the PCI event delivery callback we cannot assign
80 	 * events to specific vCPUs, so all events are delivered to vCPU#0 by
81 	 * Xen. Since the PCI interrupt can fire on any CPU by default, we
82 	 * need to bind it to vCPU#0 in order to ensure that
83 	 * xen_intr_handle_upcall always gets called on vCPU#0.
84 	 */
85 	error = BUS_BIND_INTR(device_get_parent(device), device,
86 	                      scp->res_irq, 0);
87 	if (error)
88 		return error;
89 #endif
90 
91 	xen_hvm_set_callback(device);
92 	return (0);
93 }
94 
95 /*
96  * Deallocate anything allocated by xenpci_allocate_resources.
97  */
98 static int
99 xenpci_deallocate_resources(device_t dev)
100 {
101 	struct xenpci_softc *scp = device_get_softc(dev);
102 
103 	if (scp->res_irq != 0) {
104 		bus_deactivate_resource(dev, SYS_RES_IRQ,
105 			scp->rid_irq, scp->res_irq);
106 		bus_release_resource(dev, SYS_RES_IRQ,
107 			scp->rid_irq, scp->res_irq);
108 		scp->res_irq = 0;
109 	}
110 
111 	return (0);
112 }
113 
114 /*
115  * Allocate irq and memory resources.
116  */
117 static int
118 xenpci_allocate_resources(device_t dev)
119 {
120 	struct xenpci_softc *scp = device_get_softc(dev);
121 
122 	scp->res_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ,
123 			&scp->rid_irq, RF_SHAREABLE|RF_ACTIVE);
124 	if (scp->res_irq == NULL) {
125 		printf("xenpci Could not allocate irq.\n");
126 		goto errexit;
127 	}
128 
129 	return (0);
130 
131 errexit:
132 	/* Cleanup anything we may have assigned. */
133 	xenpci_deallocate_resources(dev);
134 	return (ENXIO); /* For want of a better idea. */
135 }
136 
137 /*
138  * Probe - just check device ID.
139  */
140 static int
141 xenpci_probe(device_t dev)
142 {
143 
144 	if (pci_get_devid(dev) != 0x00015853)
145 		return (ENXIO);
146 
147 	device_set_desc(dev, "Xen Platform Device");
148 	return (BUS_PROBE_DEFAULT);
149 }
150 
151 /*
152  * Attach - find resources and talk to Xen.
153  */
154 static int
155 xenpci_attach(device_t dev)
156 {
157 	struct xenpci_softc *scp = device_get_softc(dev);
158 	int error;
159 
160 	error = xenpci_allocate_resources(dev);
161 	if (error) {
162 		device_printf(dev, "xenpci_allocate_resources failed(%d).\n",
163 		    error);
164 		goto errexit;
165 	}
166 
167 	/*
168 	 * Hook the irq up to evtchn
169 	 */
170 	error = xenpci_irq_init(dev, scp);
171 	if (error) {
172 		device_printf(dev, "xenpci_irq_init failed(%d).\n",
173 			error);
174 		goto errexit;
175 	}
176 
177 	return (0);
178 
179 errexit:
180 	/*
181 	 * Undo anything we may have done.
182 	 */
183 	xenpci_deallocate_resources(dev);
184 	return (error);
185 }
186 
187 /*
188  * Detach - reverse anything done by attach.
189  */
190 static int
191 xenpci_detach(device_t dev)
192 {
193 	struct xenpci_softc *scp = device_get_softc(dev);
194 	device_t parent = device_get_parent(dev);
195 
196 	/*
197 	 * Take our interrupt handler out of the list of handlers
198 	 * that can handle this irq.
199 	 */
200 	if (scp->intr_cookie != NULL) {
201 		if (BUS_TEARDOWN_INTR(parent, dev,
202 		    scp->res_irq, scp->intr_cookie) != 0)
203 			device_printf(dev,
204 			    "intr teardown failed.. continuing\n");
205 		scp->intr_cookie = NULL;
206 	}
207 
208 	/*
209 	 * Deallocate any system resources we may have
210 	 * allocated on behalf of this driver.
211 	 */
212 	return (xenpci_deallocate_resources(dev));
213 }
214 
215 static int
216 xenpci_resume(device_t dev)
217 {
218 	xen_hvm_set_callback(dev);
219 	return (0);
220 }
221 
222 static device_method_t xenpci_methods[] = {
223 	/* Device interface */
224 	DEVMETHOD(device_probe,		xenpci_probe),
225 	DEVMETHOD(device_attach,	xenpci_attach),
226 	DEVMETHOD(device_detach,	xenpci_detach),
227 	DEVMETHOD(device_resume,	xenpci_resume),
228 
229 	{ 0, 0 }
230 };
231 
232 static driver_t xenpci_driver = {
233 	"xenpci",
234 	xenpci_methods,
235 	sizeof(struct xenpci_softc),
236 };
237 
238 DRIVER_MODULE(xenpci, pci, xenpci_driver, xenpci_devclass, 0, 0);
239