xref: /freebsd/sys/dev/xen/xenpci/xenpci.c (revision ad30f8e79bd1007cc2476e491bd21b4f5e389e0a)
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 #include <sys/proc.h>
36 #include <sys/systm.h>
37 #include <sys/time.h>
38 
39 #include <machine/bus.h>
40 #include <machine/resource.h>
41 #include <sys/rman.h>
42 
43 #include <machine/stdarg.h>
44 #include <machine/xen/xen-os.h>
45 #include <xen/features.h>
46 #include <xen/hypervisor.h>
47 #include <xen/gnttab.h>
48 #include <xen/xen_intr.h>
49 #include <xen/interface/memory.h>
50 #include <xen/interface/hvm/params.h>
51 
52 #include <dev/pci/pcireg.h>
53 #include <dev/pci/pcivar.h>
54 
55 #include <vm/vm.h>
56 #include <vm/vm_extern.h>
57 #include <vm/vm_kern.h>
58 #include <vm/pmap.h>
59 
60 #include <dev/xen/xenpci/xenpcivar.h>
61 
62 /*
63  * These variables are used by the rest of the kernel to access the
64  * hypervisor.
65  */
66 char *hypercall_stubs;
67 shared_info_t *HYPERVISOR_shared_info;
68 static vm_paddr_t shared_info_pa;
69 static device_t nexus;
70 
71 /*
72  * This is used to find our platform device instance.
73  */
74 static devclass_t xenpci_devclass;
75 
76 /*
77  * Return the CPUID base address for Xen functions.
78  */
79 static uint32_t
80 xenpci_cpuid_base(void)
81 {
82 	uint32_t base, regs[4];
83 
84 	for (base = 0x40000000; base < 0x40010000; base += 0x100) {
85 		do_cpuid(base, regs);
86 		if (!memcmp("XenVMMXenVMM", &regs[1], 12)
87 		    && (regs[0] - base) >= 2)
88 			return (base);
89 	}
90 	return (0);
91 }
92 
93 /*
94  * Allocate and fill in the hypcall page.
95  */
96 static int
97 xenpci_init_hypercall_stubs(device_t dev, struct xenpci_softc * scp)
98 {
99 	uint32_t base, regs[4];
100 	int i;
101 
102 	base = xenpci_cpuid_base();
103 	if (!base) {
104 		device_printf(dev, "Xen platform device but not Xen VMM\n");
105 		return (EINVAL);
106 	}
107 
108 	if (bootverbose) {
109 		do_cpuid(base + 1, regs);
110 		device_printf(dev, "Xen version %d.%d.\n",
111 		    regs[0] >> 16, regs[0] & 0xffff);
112 	}
113 
114 	/*
115 	 * Find the hypercall pages.
116 	 */
117 	do_cpuid(base + 2, regs);
118 
119 	hypercall_stubs = malloc(regs[0] * PAGE_SIZE, M_TEMP, M_WAITOK);
120 
121 	for (i = 0; i < regs[0]; i++) {
122 		wrmsr(regs[1], vtophys(hypercall_stubs + i * PAGE_SIZE) + i);
123 	}
124 
125 	return (0);
126 }
127 
128 /*
129  * After a resume, re-initialise the hypercall page.
130  */
131 static void
132 xenpci_resume_hypercall_stubs(device_t dev, struct xenpci_softc * scp)
133 {
134 	uint32_t base, regs[4];
135 	int i;
136 
137 	base = xenpci_cpuid_base();
138 
139 	do_cpuid(base + 2, regs);
140 	for (i = 0; i < regs[0]; i++) {
141 		wrmsr(regs[1], vtophys(hypercall_stubs + i * PAGE_SIZE) + i);
142 	}
143 }
144 
145 /*
146  * Tell the hypervisor how to contact us for event channel callbacks.
147  */
148 static void
149 xenpci_set_callback(device_t dev)
150 {
151 	int irq;
152 	uint64_t callback;
153 	struct xen_hvm_param xhp;
154 
155 	irq = pci_get_irq(dev);
156 	if (irq < 16) {
157 		callback = irq;
158 	} else {
159 		callback = (pci_get_intpin(dev) - 1) & 3;
160 		callback |= pci_get_slot(dev) << 11;
161 		callback |= 1ull << 56;
162 	}
163 
164 	xhp.domid = DOMID_SELF;
165 	xhp.index = HVM_PARAM_CALLBACK_IRQ;
166 	xhp.value = callback;
167 	if (HYPERVISOR_hvm_op(HVMOP_set_param, &xhp))
168 		panic("Can't set evtchn callback");
169 }
170 
171 
172 /*
173  * Deallocate anything allocated by xenpci_allocate_resources.
174  */
175 static int
176 xenpci_deallocate_resources(device_t dev)
177 {
178 	struct xenpci_softc *scp = device_get_softc(dev);
179 
180 	if (scp->res_irq != 0) {
181 		bus_deactivate_resource(dev, SYS_RES_IRQ,
182 			scp->rid_irq, scp->res_irq);
183 		bus_release_resource(dev, SYS_RES_IRQ,
184 			scp->rid_irq, scp->res_irq);
185 		scp->res_irq = 0;
186 	}
187 	if (scp->res_memory != 0) {
188 		bus_deactivate_resource(dev, SYS_RES_MEMORY,
189 			scp->rid_memory, scp->res_memory);
190 		bus_release_resource(dev, SYS_RES_MEMORY,
191 			scp->rid_memory, scp->res_memory);
192 		scp->res_memory = 0;
193 	}
194 
195 	return (0);
196 }
197 
198 /*
199  * Allocate irq and memory resources.
200  */
201 static int
202 xenpci_allocate_resources(device_t dev)
203 {
204 	struct xenpci_softc *scp = device_get_softc(dev);
205 
206 	scp->res_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ,
207 			&scp->rid_irq, RF_SHAREABLE|RF_ACTIVE);
208 	if (scp->res_irq == NULL) {
209 		printf("xenpci Could not allocate irq.\n");
210 		goto errexit;
211 	}
212 
213 	scp->rid_memory = PCIR_BAR(1);
214 	scp->res_memory = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
215 			&scp->rid_memory, RF_ACTIVE);
216 	if (scp->res_memory == NULL) {
217 		printf("xenpci Could not allocate memory bar.\n");
218 		goto errexit;
219 	}
220 
221 	scp->phys_next = rman_get_start(scp->res_memory);
222 
223 	return (0);
224 
225 errexit:
226 	/* Cleanup anything we may have assigned. */
227 	xenpci_deallocate_resources(dev);
228 	return (ENXIO); /* For want of a better idea. */
229 }
230 
231 /*
232  * Allocate a physical address range from our mmio region.
233  */
234 static int
235 xenpci_alloc_space_int(struct xenpci_softc *scp, size_t sz,
236     vm_paddr_t *pa)
237 {
238 
239 	if (scp->phys_next + sz > rman_get_end(scp->res_memory)) {
240 		return (ENOMEM);
241 	}
242 
243 	*pa = scp->phys_next;
244 	scp->phys_next += sz;
245 
246 	return (0);
247 }
248 
249 /*
250  * Allocate a physical address range from our mmio region.
251  */
252 int
253 xenpci_alloc_space(size_t sz, vm_paddr_t *pa)
254 {
255 	device_t dev = devclass_get_device(xenpci_devclass, 0);
256 
257 	if (dev) {
258 		return (xenpci_alloc_space_int(device_get_softc(dev),
259 			sz, pa));
260 	} else {
261 		return (ENOMEM);
262 	}
263 }
264 
265 static struct resource *
266 xenpci_alloc_resource(device_t dev, device_t child, int type, int *rid,
267     u_long start, u_long end, u_long count, u_int flags)
268 {
269 	return (BUS_ALLOC_RESOURCE(nexus, child, type, rid, start,
270 	    end, count, flags));
271 }
272 
273 
274 static int
275 xenpci_release_resource(device_t dev, device_t child, int type, int rid,
276     struct resource *r)
277 {
278 	return (BUS_RELEASE_RESOURCE(nexus, child, type, rid, r));
279 }
280 
281 static int
282 xenpci_activate_resource(device_t dev, device_t child, int type, int rid,
283     struct resource *r)
284 {
285 	return (BUS_ACTIVATE_RESOURCE(nexus, child, type, rid, r));
286 }
287 
288 static int
289 xenpci_deactivate_resource(device_t dev, device_t child, int type,
290     int rid, struct resource *r)
291 {
292 	return (BUS_DEACTIVATE_RESOURCE(nexus, child, type, rid, r));
293 }
294 
295 /*
296  * Called very early in the resume sequence - reinitialise the various
297  * bits of Xen machinery including the hypercall page and the shared
298  * info page.
299  */
300 void
301 xenpci_resume()
302 {
303 	device_t dev = devclass_get_device(xenpci_devclass, 0);
304 	struct xenpci_softc *scp = device_get_softc(dev);
305 	struct xen_add_to_physmap xatp;
306 
307 	xenpci_resume_hypercall_stubs(dev, scp);
308 
309 	xatp.domid = DOMID_SELF;
310 	xatp.idx = 0;
311 	xatp.space = XENMAPSPACE_shared_info;
312 	xatp.gpfn = shared_info_pa >> PAGE_SHIFT;
313 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
314 		panic("HYPERVISOR_memory_op failed");
315 
316 	pmap_kenter((vm_offset_t) HYPERVISOR_shared_info, shared_info_pa);
317 
318 	xenpci_set_callback(dev);
319 
320 	gnttab_resume();
321 	irq_resume();
322 }
323 
324 /*
325  * Probe - just check device ID.
326  */
327 static int
328 xenpci_probe(device_t dev)
329 {
330 
331 	if (pci_get_devid(dev) != 0x00015853)
332 		return (ENXIO);
333 
334 	device_set_desc(dev, "Xen Platform Device");
335 	return (bus_generic_probe(dev));
336 }
337 
338 /*
339  * Attach - find resources and talk to Xen.
340  */
341 static int
342 xenpci_attach(device_t dev)
343 {
344 	int error;
345 	struct xenpci_softc *scp = device_get_softc(dev);
346 	struct xen_add_to_physmap xatp;
347 	vm_offset_t shared_va;
348 	devclass_t dc;
349 
350 	/*
351 	 * Find and record nexus0.  Since we are not really on the
352 	 * PCI bus, all resource operations are directed to nexus
353 	 * instead of through our parent.
354 	 */
355 	if ((dc = devclass_find("nexus"))  == 0
356 	 || (nexus = devclass_get_device(dc, 0)) == 0) {
357 		device_printf(dev, "unable to find nexus.");
358 		return (ENOENT);
359 	}
360 
361 	error = xenpci_allocate_resources(dev);
362 	if (error) {
363 		device_printf(dev, "xenpci_allocate_resources failed(%d).\n",
364 		    error);
365 		goto errexit;
366 	}
367 
368 	error = xenpci_init_hypercall_stubs(dev, scp);
369 	if (error) {
370 		device_printf(dev, "xenpci_init_hypercall_stubs failed(%d).\n",
371 		    error);
372 		goto errexit;
373 	}
374 
375 	setup_xen_features();
376 
377 	xenpci_alloc_space_int(scp, PAGE_SIZE, &shared_info_pa);
378 
379 	xatp.domid = DOMID_SELF;
380 	xatp.idx = 0;
381 	xatp.space = XENMAPSPACE_shared_info;
382 	xatp.gpfn = shared_info_pa >> PAGE_SHIFT;
383 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
384 		panic("HYPERVISOR_memory_op failed");
385 
386 	shared_va = kmem_alloc_nofault(kernel_map, PAGE_SIZE);
387 	pmap_kenter(shared_va, shared_info_pa);
388 	HYPERVISOR_shared_info = (void *) shared_va;
389 
390 	/*
391 	 * Hook the irq up to evtchn
392 	 */
393 	xenpci_irq_init(dev, scp);
394 	xenpci_set_callback(dev);
395 
396 	return (bus_generic_attach(dev));
397 
398 errexit:
399 	/*
400 	 * Undo anything we may have done.
401 	 */
402 	xenpci_deallocate_resources(dev);
403 	return (error);
404 }
405 
406 /*
407  * Detach - reverse anything done by attach.
408  */
409 static int
410 xenpci_detach(device_t dev)
411 {
412 	struct xenpci_softc *scp = device_get_softc(dev);
413 	device_t parent = device_get_parent(dev);
414 
415 	/*
416 	 * Take our interrupt handler out of the list of handlers
417 	 * that can handle this irq.
418 	 */
419 	if (scp->intr_cookie != NULL) {
420 		if (BUS_TEARDOWN_INTR(parent, dev,
421 		    scp->res_irq, scp->intr_cookie) != 0)
422 			device_printf(dev,
423 			    "intr teardown failed.. continuing\n");
424 		scp->intr_cookie = NULL;
425 	}
426 
427 	/*
428 	 * Deallocate any system resources we may have
429 	 * allocated on behalf of this driver.
430 	 */
431 	return (xenpci_deallocate_resources(dev));
432 }
433 
434 static device_method_t xenpci_methods[] = {
435 	/* Device interface */
436 	DEVMETHOD(device_probe,		xenpci_probe),
437 	DEVMETHOD(device_attach,	xenpci_attach),
438 	DEVMETHOD(device_detach,	xenpci_detach),
439 	DEVMETHOD(device_suspend,	bus_generic_suspend),
440 	DEVMETHOD(device_resume,	bus_generic_resume),
441 
442 	/* Bus interface */
443 	DEVMETHOD(bus_add_child,	bus_generic_add_child),
444 	DEVMETHOD(bus_alloc_resource,   xenpci_alloc_resource),
445 	DEVMETHOD(bus_release_resource, xenpci_release_resource),
446 	DEVMETHOD(bus_activate_resource, xenpci_activate_resource),
447 	DEVMETHOD(bus_deactivate_resource, xenpci_deactivate_resource),
448 
449 	{ 0, 0 }
450 };
451 
452 static driver_t xenpci_driver = {
453 	"xenpci",
454 	xenpci_methods,
455 	sizeof(struct xenpci_softc),
456 };
457 
458 DRIVER_MODULE(xenpci, pci, xenpci_driver, xenpci_devclass, 0, 0);
459