xref: /openbmc/linux/arch/arm/xen/enlighten.c (revision 78700c0a)
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/paravirt.h>
16 #include <asm/xen/hypervisor.h>
17 #include <asm/xen/hypercall.h>
18 #include <asm/system_misc.h>
19 #include <linux/interrupt.h>
20 #include <linux/irqreturn.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/of_irq.h>
24 #include <linux/of_address.h>
25 #include <linux/cpuidle.h>
26 #include <linux/cpufreq.h>
27 #include <linux/cpu.h>
28 #include <linux/console.h>
29 #include <linux/pvclock_gtod.h>
30 #include <linux/time64.h>
31 #include <linux/timekeeping.h>
32 #include <linux/timekeeper_internal.h>
33 
34 #include <linux/mm.h>
35 
36 struct start_info _xen_start_info;
37 struct start_info *xen_start_info = &_xen_start_info;
38 EXPORT_SYMBOL(xen_start_info);
39 
40 enum xen_domain_type xen_domain_type = XEN_NATIVE;
41 EXPORT_SYMBOL(xen_domain_type);
42 
43 struct shared_info xen_dummy_shared_info;
44 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
45 
46 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
47 static struct vcpu_info __percpu *xen_vcpu_info;
48 
49 /* These are unused until we support booting "pre-ballooned" */
50 unsigned long xen_released_pages;
51 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
52 
53 static __read_mostly unsigned int xen_events_irq;
54 
55 static __initdata struct device_node *xen_node;
56 
57 int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
58 			       unsigned long addr,
59 			       xen_pfn_t *gfn, int nr,
60 			       int *err_ptr, pgprot_t prot,
61 			       unsigned domid,
62 			       struct page **pages)
63 {
64 	return xen_xlate_remap_gfn_array(vma, addr, gfn, nr, err_ptr,
65 					 prot, domid, pages);
66 }
67 EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_array);
68 
69 /* Not used by XENFEAT_auto_translated guests. */
70 int xen_remap_domain_gfn_range(struct vm_area_struct *vma,
71                               unsigned long addr,
72                               xen_pfn_t gfn, int nr,
73                               pgprot_t prot, unsigned domid,
74                               struct page **pages)
75 {
76 	return -ENOSYS;
77 }
78 EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_range);
79 
80 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
81 			       int nr, struct page **pages)
82 {
83 	return xen_xlate_unmap_gfn_range(vma, nr, pages);
84 }
85 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
86 
87 static unsigned long long xen_stolen_accounting(int cpu)
88 {
89 	struct vcpu_runstate_info state;
90 
91 	BUG_ON(cpu != smp_processor_id());
92 
93 	xen_get_runstate_snapshot(&state);
94 
95 	WARN_ON(state.state != RUNSTATE_running);
96 
97 	return state.time[RUNSTATE_runnable] + state.time[RUNSTATE_offline];
98 }
99 
100 static void xen_read_wallclock(struct timespec64 *ts)
101 {
102 	u32 version;
103 	struct timespec64 now, ts_monotonic;
104 	struct shared_info *s = HYPERVISOR_shared_info;
105 	struct pvclock_wall_clock *wall_clock = &(s->wc);
106 
107 	/* get wallclock at system boot */
108 	do {
109 		version = wall_clock->version;
110 		rmb();		/* fetch version before time */
111 		now.tv_sec  = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
112 		now.tv_nsec = wall_clock->nsec;
113 		rmb();		/* fetch time before checking version */
114 	} while ((wall_clock->version & 1) || (version != wall_clock->version));
115 
116 	/* time since system boot */
117 	ktime_get_ts64(&ts_monotonic);
118 	*ts = timespec64_add(now, ts_monotonic);
119 }
120 
121 static int xen_pvclock_gtod_notify(struct notifier_block *nb,
122 				   unsigned long was_set, void *priv)
123 {
124 	/* Protected by the calling core code serialization */
125 	static struct timespec64 next_sync;
126 
127 	struct xen_platform_op op;
128 	struct timespec64 now, system_time;
129 	struct timekeeper *tk = priv;
130 
131 	now.tv_sec = tk->xtime_sec;
132 	now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
133 	system_time = timespec64_add(now, tk->wall_to_monotonic);
134 
135 	/*
136 	 * We only take the expensive HV call when the clock was set
137 	 * or when the 11 minutes RTC synchronization time elapsed.
138 	 */
139 	if (!was_set && timespec64_compare(&now, &next_sync) < 0)
140 		return NOTIFY_OK;
141 
142 	op.cmd = XENPF_settime64;
143 	op.u.settime64.mbz = 0;
144 	op.u.settime64.secs = now.tv_sec;
145 	op.u.settime64.nsecs = now.tv_nsec;
146 	op.u.settime64.system_time = timespec64_to_ns(&system_time);
147 	(void)HYPERVISOR_platform_op(&op);
148 
149 	/*
150 	 * Move the next drift compensation time 11 minutes
151 	 * ahead. That's emulating the sync_cmos_clock() update for
152 	 * the hardware RTC.
153 	 */
154 	next_sync = now;
155 	next_sync.tv_sec += 11 * 60;
156 
157 	return NOTIFY_OK;
158 }
159 
160 static struct notifier_block xen_pvclock_gtod_notifier = {
161 	.notifier_call = xen_pvclock_gtod_notify,
162 };
163 
164 static void xen_percpu_init(void)
165 {
166 	struct vcpu_register_vcpu_info info;
167 	struct vcpu_info *vcpup;
168 	int err;
169 	int cpu = get_cpu();
170 
171 	/*
172 	 * VCPUOP_register_vcpu_info cannot be called twice for the same
173 	 * vcpu, so if vcpu_info is already registered, just get out. This
174 	 * can happen with cpu-hotplug.
175 	 */
176 	if (per_cpu(xen_vcpu, cpu) != NULL)
177 		goto after_register_vcpu_info;
178 
179 	pr_info("Xen: initializing cpu%d\n", cpu);
180 	vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
181 
182 	info.mfn = virt_to_gfn(vcpup);
183 	info.offset = xen_offset_in_page(vcpup);
184 
185 	err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
186 	BUG_ON(err);
187 	per_cpu(xen_vcpu, cpu) = vcpup;
188 
189 	xen_setup_runstate_info(cpu);
190 
191 after_register_vcpu_info:
192 	enable_percpu_irq(xen_events_irq, 0);
193 	put_cpu();
194 }
195 
196 static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
197 {
198 	struct sched_shutdown r = { .reason = SHUTDOWN_reboot };
199 	int rc;
200 	rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
201 	BUG_ON(rc);
202 }
203 
204 static void xen_power_off(void)
205 {
206 	struct sched_shutdown r = { .reason = SHUTDOWN_poweroff };
207 	int rc;
208 	rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
209 	BUG_ON(rc);
210 }
211 
212 static int xen_cpu_notification(struct notifier_block *self,
213 				unsigned long action,
214 				void *hcpu)
215 {
216 	switch (action) {
217 	case CPU_STARTING:
218 		xen_percpu_init();
219 		break;
220 	case CPU_DYING:
221 		disable_percpu_irq(xen_events_irq);
222 		break;
223 	default:
224 		break;
225 	}
226 
227 	return NOTIFY_OK;
228 }
229 
230 static struct notifier_block xen_cpu_notifier = {
231 	.notifier_call = xen_cpu_notification,
232 };
233 
234 static irqreturn_t xen_arm_callback(int irq, void *arg)
235 {
236 	xen_hvm_evtchn_do_upcall();
237 	return IRQ_HANDLED;
238 }
239 
240 /*
241  * see Documentation/devicetree/bindings/arm/xen.txt for the
242  * documentation of the Xen Device Tree format.
243  */
244 #define GRANT_TABLE_PHYSADDR 0
245 void __init xen_early_init(void)
246 {
247 	int len;
248 	const char *s = NULL;
249 	const char *version = NULL;
250 	const char *xen_prefix = "xen,xen-";
251 
252 	xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
253 	if (!xen_node) {
254 		pr_debug("No Xen support\n");
255 		return;
256 	}
257 	s = of_get_property(xen_node, "compatible", &len);
258 	if (strlen(xen_prefix) + 3  < len &&
259 			!strncmp(xen_prefix, s, strlen(xen_prefix)))
260 		version = s + strlen(xen_prefix);
261 	if (version == NULL) {
262 		pr_debug("Xen version not found\n");
263 		return;
264 	}
265 
266 	pr_info("Xen %s support found\n", version);
267 
268 	xen_domain_type = XEN_HVM_DOMAIN;
269 
270 	xen_setup_features();
271 
272 	if (xen_feature(XENFEAT_dom0))
273 		xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
274 	else
275 		xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
276 
277 	if (!console_set_on_cmdline && !xen_initial_domain())
278 		add_preferred_console("hvc", 0, NULL);
279 }
280 
281 static int __init xen_guest_init(void)
282 {
283 	struct xen_add_to_physmap xatp;
284 	struct shared_info *shared_info_page = NULL;
285 	struct resource res;
286 	phys_addr_t grant_frames;
287 
288 	if (!xen_domain())
289 		return 0;
290 
291 	if (of_address_to_resource(xen_node, GRANT_TABLE_PHYSADDR, &res)) {
292 		pr_err("Xen grant table base address not found\n");
293 		return -ENODEV;
294 	}
295 	grant_frames = res.start;
296 
297 	xen_events_irq = irq_of_parse_and_map(xen_node, 0);
298 	if (!xen_events_irq) {
299 		pr_err("Xen event channel interrupt not found\n");
300 		return -ENODEV;
301 	}
302 
303 	shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
304 
305 	if (!shared_info_page) {
306 		pr_err("not enough memory\n");
307 		return -ENOMEM;
308 	}
309 	xatp.domid = DOMID_SELF;
310 	xatp.idx = 0;
311 	xatp.space = XENMAPSPACE_shared_info;
312 	xatp.gpfn = virt_to_gfn(shared_info_page);
313 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
314 		BUG();
315 
316 	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
317 
318 	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
319 	 * page, we use it in the event channel upcall and in some pvclock
320 	 * related functions.
321 	 * The shared info contains exactly 1 CPU (the boot CPU). The guest
322 	 * is required to use VCPUOP_register_vcpu_info to place vcpu info
323 	 * for secondary CPUs as they are brought up.
324 	 * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
325 	 */
326 	xen_vcpu_info = __alloc_percpu(sizeof(struct vcpu_info),
327 			                       sizeof(struct vcpu_info));
328 	if (xen_vcpu_info == NULL)
329 		return -ENOMEM;
330 
331 	if (gnttab_setup_auto_xlat_frames(grant_frames)) {
332 		free_percpu(xen_vcpu_info);
333 		return -ENOMEM;
334 	}
335 	gnttab_init();
336 	if (!xen_initial_domain())
337 		xenbus_probe(NULL);
338 
339 	/*
340 	 * Making sure board specific code will not set up ops for
341 	 * cpu idle and cpu freq.
342 	 */
343 	disable_cpuidle();
344 	disable_cpufreq();
345 
346 	xen_init_IRQ();
347 
348 	if (request_percpu_irq(xen_events_irq, xen_arm_callback,
349 			       "events", &xen_vcpu)) {
350 		pr_err("Error request IRQ %d\n", xen_events_irq);
351 		return -EINVAL;
352 	}
353 
354 	xen_percpu_init();
355 
356 	register_cpu_notifier(&xen_cpu_notifier);
357 
358 	pv_time_ops.steal_clock = xen_stolen_accounting;
359 	static_key_slow_inc(&paravirt_steal_enabled);
360 	if (xen_initial_domain())
361 		pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
362 
363 	return 0;
364 }
365 early_initcall(xen_guest_init);
366 
367 static int __init xen_pm_init(void)
368 {
369 	if (!xen_domain())
370 		return -ENODEV;
371 
372 	pm_power_off = xen_power_off;
373 	arm_pm_restart = xen_restart;
374 	if (!xen_initial_domain()) {
375 		struct timespec64 ts;
376 		xen_read_wallclock(&ts);
377 		do_settimeofday64(&ts);
378 	}
379 
380 	return 0;
381 }
382 late_initcall(xen_pm_init);
383 
384 
385 /* empty stubs */
386 void xen_arch_pre_suspend(void) { }
387 void xen_arch_post_suspend(int suspend_cancelled) { }
388 void xen_timer_resume(void) { }
389 void xen_arch_resume(void) { }
390 void xen_arch_suspend(void) { }
391 
392 
393 /* In the hypercall.S file. */
394 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
395 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
396 EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
397 EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
398 EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
399 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
400 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
401 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
402 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
403 EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
404 EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op);
405 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
406 EXPORT_SYMBOL_GPL(privcmd_call);
407