xref: /freebsd/sys/dev/xen/xenpci/xenpci.c (revision 1b833d535b9ce1789dca84d8bd15d22e1ed58d46)
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 
47 #include <dev/pci/pcireg.h>
48 #include <dev/pci/pcivar.h>
49 
50 #include <dev/xen/xenpci/xenpcivar.h>
51 
52 extern void xen_intr_handle_upcall(struct trapframe *trap_frame);
53 
54 /*
55  * This is used to find our platform device instance.
56  */
57 static devclass_t xenpci_devclass;
58 
59 static int
60 xenpci_intr_filter(void *trap_frame)
61 {
62 	xen_intr_handle_upcall(trap_frame);
63 	return (FILTER_HANDLED);
64 }
65 
66 static int
67 xenpci_irq_init(device_t device, struct xenpci_softc *scp)
68 {
69 	int error;
70 
71 	error = BUS_SETUP_INTR(device_get_parent(device), device,
72 			       scp->res_irq, INTR_MPSAFE|INTR_TYPE_MISC,
73 			       xenpci_intr_filter, NULL, /*trap_frame*/NULL,
74 			       &scp->intr_cookie);
75 	if (error)
76 		return error;
77 
78 #ifdef SMP
79 	/*
80 	 * When using the PCI event delivery callback we cannot assign
81 	 * events to specific vCPUs, so all events are delivered to vCPU#0 by
82 	 * Xen. Since the PCI interrupt can fire on any CPU by default, we
83 	 * need to bind it to vCPU#0 in order to ensure that
84 	 * xen_intr_handle_upcall always gets called on vCPU#0.
85 	 */
86 	error = BUS_BIND_INTR(device_get_parent(device), device,
87 	                      scp->res_irq, 0);
88 	if (error)
89 		return error;
90 #endif
91 
92 	xen_hvm_set_callback(device);
93 	return (0);
94 }
95 
96 /*
97  * Deallocate anything allocated by xenpci_allocate_resources.
98  */
99 static int
100 xenpci_deallocate_resources(device_t dev)
101 {
102 	struct xenpci_softc *scp = device_get_softc(dev);
103 
104 	if (scp->res_irq != 0) {
105 		bus_deactivate_resource(dev, SYS_RES_IRQ,
106 			scp->rid_irq, scp->res_irq);
107 		bus_release_resource(dev, SYS_RES_IRQ,
108 			scp->rid_irq, scp->res_irq);
109 		scp->res_irq = 0;
110 	}
111 
112 	return (0);
113 }
114 
115 /*
116  * Allocate irq and memory resources.
117  */
118 static int
119 xenpci_allocate_resources(device_t dev)
120 {
121 	struct xenpci_softc *scp = device_get_softc(dev);
122 
123 	scp->res_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ,
124 			&scp->rid_irq, RF_SHAREABLE|RF_ACTIVE);
125 	if (scp->res_irq == NULL) {
126 		printf("xenpci Could not allocate irq.\n");
127 		goto errexit;
128 	}
129 
130 	return (0);
131 
132 errexit:
133 	/* Cleanup anything we may have assigned. */
134 	xenpci_deallocate_resources(dev);
135 	return (ENXIO); /* For want of a better idea. */
136 }
137 
138 /*
139  * Probe - just check device ID.
140  */
141 static int
142 xenpci_probe(device_t dev)
143 {
144 
145 	if (pci_get_devid(dev) != 0x00015853)
146 		return (ENXIO);
147 
148 	device_set_desc(dev, "Xen Platform Device");
149 	return (BUS_PROBE_DEFAULT);
150 }
151 
152 /*
153  * Attach - find resources and talk to Xen.
154  */
155 static int
156 xenpci_attach(device_t dev)
157 {
158 	struct xenpci_softc *scp = device_get_softc(dev);
159 	int error;
160 
161 	error = xenpci_allocate_resources(dev);
162 	if (error) {
163 		device_printf(dev, "xenpci_allocate_resources failed(%d).\n",
164 		    error);
165 		goto errexit;
166 	}
167 
168 	/*
169 	 * Hook the irq up to evtchn
170 	 */
171 	error = xenpci_irq_init(dev, scp);
172 	if (error) {
173 		device_printf(dev, "xenpci_irq_init failed(%d).\n",
174 			error);
175 		goto errexit;
176 	}
177 
178 	return (0);
179 
180 errexit:
181 	/*
182 	 * Undo anything we may have done.
183 	 */
184 	xenpci_deallocate_resources(dev);
185 	return (error);
186 }
187 
188 /*
189  * Detach - reverse anything done by attach.
190  */
191 static int
192 xenpci_detach(device_t dev)
193 {
194 	struct xenpci_softc *scp = device_get_softc(dev);
195 	device_t parent = device_get_parent(dev);
196 
197 	/*
198 	 * Take our interrupt handler out of the list of handlers
199 	 * that can handle this irq.
200 	 */
201 	if (scp->intr_cookie != NULL) {
202 		if (BUS_TEARDOWN_INTR(parent, dev,
203 		    scp->res_irq, scp->intr_cookie) != 0)
204 			device_printf(dev,
205 			    "intr teardown failed.. continuing\n");
206 		scp->intr_cookie = NULL;
207 	}
208 
209 	/*
210 	 * Deallocate any system resources we may have
211 	 * allocated on behalf of this driver.
212 	 */
213 	return (xenpci_deallocate_resources(dev));
214 }
215 
216 static int
217 xenpci_resume(device_t dev)
218 {
219 	xen_hvm_set_callback(dev);
220 	return (0);
221 }
222 
223 static device_method_t xenpci_methods[] = {
224 	/* Device interface */
225 	DEVMETHOD(device_probe,		xenpci_probe),
226 	DEVMETHOD(device_attach,	xenpci_attach),
227 	DEVMETHOD(device_detach,	xenpci_detach),
228 	DEVMETHOD(device_resume,	xenpci_resume),
229 
230 	{ 0, 0 }
231 };
232 
233 static driver_t xenpci_driver = {
234 	"xenpci",
235 	xenpci_methods,
236 	sizeof(struct xenpci_softc),
237 };
238 
239 DRIVER_MODULE(xenpci, pci, xenpci_driver, xenpci_devclass, 0, 0);
240