xref: /openbmc/linux/arch/arm/xen/enlighten.c (revision faa16bc4)
1 #include <xen/xen.h>
2 #include <xen/events.h>
3 #include <xen/grant_table.h>
4 #include <xen/hvm.h>
5 #include <xen/interface/vcpu.h>
6 #include <xen/interface/xen.h>
7 #include <xen/interface/memory.h>
8 #include <xen/interface/hvm/params.h>
9 #include <xen/features.h>
10 #include <xen/platform_pci.h>
11 #include <xen/xenbus.h>
12 #include <xen/page.h>
13 #include <xen/interface/sched.h>
14 #include <xen/xen-ops.h>
15 #include <asm/xen/hypervisor.h>
16 #include <asm/xen/hypercall.h>
17 #include <asm/xen/xen-ops.h>
18 #include <asm/system_misc.h>
19 #include <asm/efi.h>
20 #include <linux/interrupt.h>
21 #include <linux/irqreturn.h>
22 #include <linux/module.h>
23 #include <linux/of.h>
24 #include <linux/of_fdt.h>
25 #include <linux/of_irq.h>
26 #include <linux/of_address.h>
27 #include <linux/cpuidle.h>
28 #include <linux/cpufreq.h>
29 #include <linux/cpu.h>
30 #include <linux/console.h>
31 #include <linux/pvclock_gtod.h>
32 #include <linux/time64.h>
33 #include <linux/timekeeping.h>
34 #include <linux/timekeeper_internal.h>
35 #include <linux/acpi.h>
36 
37 #include <linux/mm.h>
38 
39 struct start_info _xen_start_info;
40 struct start_info *xen_start_info = &_xen_start_info;
41 EXPORT_SYMBOL(xen_start_info);
42 
43 enum xen_domain_type xen_domain_type = XEN_NATIVE;
44 EXPORT_SYMBOL(xen_domain_type);
45 
46 struct shared_info xen_dummy_shared_info;
47 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
48 
49 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
50 static struct vcpu_info __percpu *xen_vcpu_info;
51 
52 /* Linux <-> Xen vCPU id mapping */
53 DEFINE_PER_CPU(uint32_t, xen_vcpu_id);
54 EXPORT_PER_CPU_SYMBOL(xen_vcpu_id);
55 
56 /* These are unused until we support booting "pre-ballooned" */
57 unsigned long xen_released_pages;
58 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
59 
60 static __read_mostly unsigned int xen_events_irq;
61 
62 int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
63 			       unsigned long addr,
64 			       xen_pfn_t *gfn, int nr,
65 			       int *err_ptr, pgprot_t prot,
66 			       unsigned domid,
67 			       struct page **pages)
68 {
69 	return xen_xlate_remap_gfn_array(vma, addr, gfn, nr, err_ptr,
70 					 prot, domid, pages);
71 }
72 EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_array);
73 
74 /* Not used by XENFEAT_auto_translated guests. */
75 int xen_remap_domain_gfn_range(struct vm_area_struct *vma,
76                               unsigned long addr,
77                               xen_pfn_t gfn, int nr,
78                               pgprot_t prot, unsigned domid,
79                               struct page **pages)
80 {
81 	return -ENOSYS;
82 }
83 EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_range);
84 
85 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
86 			       int nr, struct page **pages)
87 {
88 	return xen_xlate_unmap_gfn_range(vma, nr, pages);
89 }
90 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
91 
92 /* Not used by XENFEAT_auto_translated guests. */
93 int xen_remap_domain_mfn_array(struct vm_area_struct *vma,
94 			       unsigned long addr,
95 			       xen_pfn_t *mfn, int nr,
96 			       int *err_ptr, pgprot_t prot,
97 			       unsigned int domid, struct page **pages)
98 {
99 	return -ENOSYS;
100 }
101 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_array);
102 
103 static void xen_read_wallclock(struct timespec64 *ts)
104 {
105 	u32 version;
106 	struct timespec64 now, ts_monotonic;
107 	struct shared_info *s = HYPERVISOR_shared_info;
108 	struct pvclock_wall_clock *wall_clock = &(s->wc);
109 
110 	/* get wallclock at system boot */
111 	do {
112 		version = wall_clock->version;
113 		rmb();		/* fetch version before time */
114 		now.tv_sec  = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
115 		now.tv_nsec = wall_clock->nsec;
116 		rmb();		/* fetch time before checking version */
117 	} while ((wall_clock->version & 1) || (version != wall_clock->version));
118 
119 	/* time since system boot */
120 	ktime_get_ts64(&ts_monotonic);
121 	*ts = timespec64_add(now, ts_monotonic);
122 }
123 
124 static int xen_pvclock_gtod_notify(struct notifier_block *nb,
125 				   unsigned long was_set, void *priv)
126 {
127 	/* Protected by the calling core code serialization */
128 	static struct timespec64 next_sync;
129 
130 	struct xen_platform_op op;
131 	struct timespec64 now, system_time;
132 	struct timekeeper *tk = priv;
133 
134 	now.tv_sec = tk->xtime_sec;
135 	now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
136 	system_time = timespec64_add(now, tk->wall_to_monotonic);
137 
138 	/*
139 	 * We only take the expensive HV call when the clock was set
140 	 * or when the 11 minutes RTC synchronization time elapsed.
141 	 */
142 	if (!was_set && timespec64_compare(&now, &next_sync) < 0)
143 		return NOTIFY_OK;
144 
145 	op.cmd = XENPF_settime64;
146 	op.u.settime64.mbz = 0;
147 	op.u.settime64.secs = now.tv_sec;
148 	op.u.settime64.nsecs = now.tv_nsec;
149 	op.u.settime64.system_time = timespec64_to_ns(&system_time);
150 	(void)HYPERVISOR_platform_op(&op);
151 
152 	/*
153 	 * Move the next drift compensation time 11 minutes
154 	 * ahead. That's emulating the sync_cmos_clock() update for
155 	 * the hardware RTC.
156 	 */
157 	next_sync = now;
158 	next_sync.tv_sec += 11 * 60;
159 
160 	return NOTIFY_OK;
161 }
162 
163 static struct notifier_block xen_pvclock_gtod_notifier = {
164 	.notifier_call = xen_pvclock_gtod_notify,
165 };
166 
167 static int xen_starting_cpu(unsigned int cpu)
168 {
169 	struct vcpu_register_vcpu_info info;
170 	struct vcpu_info *vcpup;
171 	int err;
172 
173 	/*
174 	 * VCPUOP_register_vcpu_info cannot be called twice for the same
175 	 * vcpu, so if vcpu_info is already registered, just get out. This
176 	 * can happen with cpu-hotplug.
177 	 */
178 	if (per_cpu(xen_vcpu, cpu) != NULL)
179 		goto after_register_vcpu_info;
180 
181 	pr_info("Xen: initializing cpu%d\n", cpu);
182 	vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
183 
184 	info.mfn = virt_to_gfn(vcpup);
185 	info.offset = xen_offset_in_page(vcpup);
186 
187 	err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
188 				 &info);
189 	BUG_ON(err);
190 	per_cpu(xen_vcpu, cpu) = vcpup;
191 
192 	xen_setup_runstate_info(cpu);
193 
194 after_register_vcpu_info:
195 	enable_percpu_irq(xen_events_irq, 0);
196 	return 0;
197 }
198 
199 static int xen_dying_cpu(unsigned int cpu)
200 {
201 	disable_percpu_irq(xen_events_irq);
202 	return 0;
203 }
204 
205 void xen_reboot(int reason)
206 {
207 	struct sched_shutdown r = { .reason = reason };
208 	int rc;
209 
210 	rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
211 	BUG_ON(rc);
212 }
213 
214 static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
215 {
216 	xen_reboot(SHUTDOWN_reboot);
217 }
218 
219 
220 static void xen_power_off(void)
221 {
222 	xen_reboot(SHUTDOWN_poweroff);
223 }
224 
225 static irqreturn_t xen_arm_callback(int irq, void *arg)
226 {
227 	xen_hvm_evtchn_do_upcall();
228 	return IRQ_HANDLED;
229 }
230 
231 static __initdata struct {
232 	const char *compat;
233 	const char *prefix;
234 	const char *version;
235 	bool found;
236 } hyper_node = {"xen,xen", "xen,xen-", NULL, false};
237 
238 static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
239 				      int depth, void *data)
240 {
241 	const void *s = NULL;
242 	int len;
243 
244 	if (depth != 1 || strcmp(uname, "hypervisor") != 0)
245 		return 0;
246 
247 	if (of_flat_dt_is_compatible(node, hyper_node.compat))
248 		hyper_node.found = true;
249 
250 	s = of_get_flat_dt_prop(node, "compatible", &len);
251 	if (strlen(hyper_node.prefix) + 3  < len &&
252 	    !strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
253 		hyper_node.version = s + strlen(hyper_node.prefix);
254 
255 	/*
256 	 * Check if Xen supports EFI by checking whether there is the
257 	 * "/hypervisor/uefi" node in DT. If so, runtime services are available
258 	 * through proxy functions (e.g. in case of Xen dom0 EFI implementation
259 	 * they call special hypercall which executes relevant EFI functions)
260 	 * and that is why they are always enabled.
261 	 */
262 	if (IS_ENABLED(CONFIG_XEN_EFI)) {
263 		if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
264 		    !efi_runtime_disabled())
265 			set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
266 	}
267 
268 	return 0;
269 }
270 
271 /*
272  * see Documentation/devicetree/bindings/arm/xen.txt for the
273  * documentation of the Xen Device Tree format.
274  */
275 #define GRANT_TABLE_PHYSADDR 0
276 void __init xen_early_init(void)
277 {
278 	of_scan_flat_dt(fdt_find_hyper_node, NULL);
279 	if (!hyper_node.found) {
280 		pr_debug("No Xen support\n");
281 		return;
282 	}
283 
284 	if (hyper_node.version == NULL) {
285 		pr_debug("Xen version not found\n");
286 		return;
287 	}
288 
289 	pr_info("Xen %s support found\n", hyper_node.version);
290 
291 	xen_domain_type = XEN_HVM_DOMAIN;
292 
293 	xen_setup_features();
294 
295 	if (xen_feature(XENFEAT_dom0))
296 		xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
297 	else
298 		xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
299 
300 	if (!console_set_on_cmdline && !xen_initial_domain())
301 		add_preferred_console("hvc", 0, NULL);
302 }
303 
304 static void __init xen_acpi_guest_init(void)
305 {
306 #ifdef CONFIG_ACPI
307 	struct xen_hvm_param a;
308 	int interrupt, trigger, polarity;
309 
310 	a.domid = DOMID_SELF;
311 	a.index = HVM_PARAM_CALLBACK_IRQ;
312 
313 	if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
314 	    || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
315 		xen_events_irq = 0;
316 		return;
317 	}
318 
319 	interrupt = a.value & 0xff;
320 	trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
321 					 : ACPI_LEVEL_SENSITIVE;
322 	polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
323 					  : ACPI_ACTIVE_HIGH;
324 	xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
325 #endif
326 }
327 
328 static void __init xen_dt_guest_init(void)
329 {
330 	struct device_node *xen_node;
331 
332 	xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
333 	if (!xen_node) {
334 		pr_err("Xen support was detected before, but it has disappeared\n");
335 		return;
336 	}
337 
338 	xen_events_irq = irq_of_parse_and_map(xen_node, 0);
339 }
340 
341 static int __init xen_guest_init(void)
342 {
343 	struct xen_add_to_physmap xatp;
344 	struct shared_info *shared_info_page = NULL;
345 	int cpu;
346 
347 	if (!xen_domain())
348 		return 0;
349 
350 	if (!acpi_disabled)
351 		xen_acpi_guest_init();
352 	else
353 		xen_dt_guest_init();
354 
355 	if (!xen_events_irq) {
356 		pr_err("Xen event channel interrupt not found\n");
357 		return -ENODEV;
358 	}
359 
360 	/*
361 	 * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
362 	 * parameters are found. Force enable runtime services.
363 	 */
364 	if (efi_enabled(EFI_RUNTIME_SERVICES))
365 		xen_efi_runtime_setup();
366 
367 	shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
368 
369 	if (!shared_info_page) {
370 		pr_err("not enough memory\n");
371 		return -ENOMEM;
372 	}
373 	xatp.domid = DOMID_SELF;
374 	xatp.idx = 0;
375 	xatp.space = XENMAPSPACE_shared_info;
376 	xatp.gpfn = virt_to_gfn(shared_info_page);
377 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
378 		BUG();
379 
380 	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
381 
382 	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
383 	 * page, we use it in the event channel upcall and in some pvclock
384 	 * related functions.
385 	 * The shared info contains exactly 1 CPU (the boot CPU). The guest
386 	 * is required to use VCPUOP_register_vcpu_info to place vcpu info
387 	 * for secondary CPUs as they are brought up.
388 	 * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
389 	 */
390 	xen_vcpu_info = alloc_percpu(struct vcpu_info);
391 	if (xen_vcpu_info == NULL)
392 		return -ENOMEM;
393 
394 	/* Direct vCPU id mapping for ARM guests. */
395 	for_each_possible_cpu(cpu)
396 		per_cpu(xen_vcpu_id, cpu) = cpu;
397 
398 	xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
399 	if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
400 					  &xen_auto_xlat_grant_frames.vaddr,
401 					  xen_auto_xlat_grant_frames.count)) {
402 		free_percpu(xen_vcpu_info);
403 		return -ENOMEM;
404 	}
405 	gnttab_init();
406 	if (!xen_initial_domain())
407 		xenbus_probe(NULL);
408 
409 	/*
410 	 * Making sure board specific code will not set up ops for
411 	 * cpu idle and cpu freq.
412 	 */
413 	disable_cpuidle();
414 	disable_cpufreq();
415 
416 	xen_init_IRQ();
417 
418 	if (request_percpu_irq(xen_events_irq, xen_arm_callback,
419 			       "events", &xen_vcpu)) {
420 		pr_err("Error request IRQ %d\n", xen_events_irq);
421 		return -EINVAL;
422 	}
423 
424 	xen_time_setup_guest();
425 
426 	if (xen_initial_domain())
427 		pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
428 
429 	return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
430 				 "arm/xen:starting", xen_starting_cpu,
431 				 xen_dying_cpu);
432 }
433 early_initcall(xen_guest_init);
434 
435 static int __init xen_pm_init(void)
436 {
437 	if (!xen_domain())
438 		return -ENODEV;
439 
440 	pm_power_off = xen_power_off;
441 	arm_pm_restart = xen_restart;
442 	if (!xen_initial_domain()) {
443 		struct timespec64 ts;
444 		xen_read_wallclock(&ts);
445 		do_settimeofday64(&ts);
446 	}
447 
448 	return 0;
449 }
450 late_initcall(xen_pm_init);
451 
452 
453 /* empty stubs */
454 void xen_arch_pre_suspend(void) { }
455 void xen_arch_post_suspend(int suspend_cancelled) { }
456 void xen_timer_resume(void) { }
457 void xen_arch_resume(void) { }
458 void xen_arch_suspend(void) { }
459 
460 
461 /* In the hypercall.S file. */
462 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
463 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
464 EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
465 EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
466 EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
467 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
468 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
469 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
470 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
471 EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
472 EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op);
473 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
474 EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist);
475 EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op);
476 EXPORT_SYMBOL_GPL(privcmd_call);
477