Commit | Line | Data |
---|---|---|
f87e4cac JF |
1 | /* |
2 | * Xen SMP support | |
3 | * | |
4 | * This file implements the Xen versions of smp_ops. SMP under Xen is | |
5 | * very straightforward. Bringing a CPU up is simply a matter of | |
6 | * loading its initial context and setting it running. | |
7 | * | |
8 | * IPIs are handled through the Xen event mechanism. | |
9 | * | |
10 | * Because virtual CPUs can be scheduled onto any real CPU, there's no | |
11 | * useful topology information for the kernel to make use of. As a | |
12 | * result, all CPUs are treated as if they're single-core and | |
13 | * single-threaded. | |
f87e4cac JF |
14 | */ |
15 | #include <linux/sched.h> | |
16 | #include <linux/err.h> | |
17 | #include <linux/smp.h> | |
18 | ||
19 | #include <asm/paravirt.h> | |
20 | #include <asm/desc.h> | |
21 | #include <asm/pgtable.h> | |
22 | #include <asm/cpu.h> | |
23 | ||
24 | #include <xen/interface/xen.h> | |
25 | #include <xen/interface/vcpu.h> | |
26 | ||
27 | #include <asm/xen/interface.h> | |
28 | #include <asm/xen/hypercall.h> | |
29 | ||
30 | #include <xen/page.h> | |
31 | #include <xen/events.h> | |
32 | ||
33 | #include "xen-ops.h" | |
34 | #include "mmu.h" | |
35 | ||
0e91398f | 36 | cpumask_t xen_cpu_initialized_map; |
f87e4cac | 37 | |
3b16cf87 JA |
38 | static DEFINE_PER_CPU(int, resched_irq); |
39 | static DEFINE_PER_CPU(int, callfunc_irq); | |
40 | static DEFINE_PER_CPU(int, callfuncsingle_irq); | |
41 | static DEFINE_PER_CPU(int, debug_irq) = -1; | |
f87e4cac JF |
42 | |
43 | static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id); | |
3b16cf87 | 44 | static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id); |
f87e4cac JF |
45 | |
46 | /* | |
47 | * Reschedule call back. Nothing to do, | |
48 | * all the work is done automatically when | |
49 | * we return from the interrupt. | |
50 | */ | |
51 | static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id) | |
52 | { | |
38bb5ab4 JF |
53 | #ifdef CONFIG_X86_32 |
54 | __get_cpu_var(irq_stat).irq_resched_count++; | |
55 | #else | |
56 | add_pda(irq_resched_count, 1); | |
57 | #endif | |
58 | ||
f87e4cac JF |
59 | return IRQ_HANDLED; |
60 | } | |
61 | ||
d68d82af | 62 | static __cpuinit void cpu_bringup(void) |
f87e4cac JF |
63 | { |
64 | int cpu = smp_processor_id(); | |
65 | ||
66 | cpu_init(); | |
d68d82af | 67 | touch_softlockup_watchdog(); |
c7b75947 JF |
68 | preempt_disable(); |
69 | ||
e2a81baf | 70 | xen_enable_sysenter(); |
6fcac6d3 | 71 | xen_enable_syscall(); |
f87e4cac | 72 | |
c7b75947 JF |
73 | cpu = smp_processor_id(); |
74 | smp_store_cpu_info(cpu); | |
75 | cpu_data(cpu).x86_max_cores = 1; | |
76 | set_cpu_sibling_map(cpu); | |
f87e4cac JF |
77 | |
78 | xen_setup_cpu_clockevents(); | |
79 | ||
c7b75947 JF |
80 | cpu_set(cpu, cpu_online_map); |
81 | x86_write_percpu(cpu_state, CPU_ONLINE); | |
82 | wmb(); | |
83 | ||
f87e4cac JF |
84 | /* We can take interrupts now: we're officially "up". */ |
85 | local_irq_enable(); | |
86 | ||
87 | wmb(); /* make sure everything is out */ | |
d68d82af AN |
88 | } |
89 | ||
90 | static __cpuinit void cpu_bringup_and_idle(void) | |
91 | { | |
92 | cpu_bringup(); | |
f87e4cac JF |
93 | cpu_idle(); |
94 | } | |
95 | ||
96 | static int xen_smp_intr_init(unsigned int cpu) | |
97 | { | |
98 | int rc; | |
ee523ca1 | 99 | const char *resched_name, *callfunc_name, *debug_name; |
f87e4cac JF |
100 | |
101 | resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu); | |
102 | rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR, | |
103 | cpu, | |
104 | xen_reschedule_interrupt, | |
105 | IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, | |
106 | resched_name, | |
107 | NULL); | |
108 | if (rc < 0) | |
109 | goto fail; | |
110 | per_cpu(resched_irq, cpu) = rc; | |
111 | ||
112 | callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu); | |
113 | rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR, | |
114 | cpu, | |
115 | xen_call_function_interrupt, | |
116 | IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, | |
117 | callfunc_name, | |
118 | NULL); | |
119 | if (rc < 0) | |
120 | goto fail; | |
121 | per_cpu(callfunc_irq, cpu) = rc; | |
122 | ||
ee523ca1 JF |
123 | debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu); |
124 | rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt, | |
125 | IRQF_DISABLED | IRQF_PERCPU | IRQF_NOBALANCING, | |
126 | debug_name, NULL); | |
127 | if (rc < 0) | |
128 | goto fail; | |
129 | per_cpu(debug_irq, cpu) = rc; | |
130 | ||
3b16cf87 JA |
131 | callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu); |
132 | rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR, | |
133 | cpu, | |
134 | xen_call_function_single_interrupt, | |
135 | IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, | |
136 | callfunc_name, | |
137 | NULL); | |
138 | if (rc < 0) | |
139 | goto fail; | |
140 | per_cpu(callfuncsingle_irq, cpu) = rc; | |
141 | ||
f87e4cac JF |
142 | return 0; |
143 | ||
144 | fail: | |
145 | if (per_cpu(resched_irq, cpu) >= 0) | |
146 | unbind_from_irqhandler(per_cpu(resched_irq, cpu), NULL); | |
147 | if (per_cpu(callfunc_irq, cpu) >= 0) | |
148 | unbind_from_irqhandler(per_cpu(callfunc_irq, cpu), NULL); | |
ee523ca1 JF |
149 | if (per_cpu(debug_irq, cpu) >= 0) |
150 | unbind_from_irqhandler(per_cpu(debug_irq, cpu), NULL); | |
3b16cf87 JA |
151 | if (per_cpu(callfuncsingle_irq, cpu) >= 0) |
152 | unbind_from_irqhandler(per_cpu(callfuncsingle_irq, cpu), NULL); | |
153 | ||
f87e4cac JF |
154 | return rc; |
155 | } | |
156 | ||
c7b75947 | 157 | static void __init xen_fill_possible_map(void) |
f87e4cac JF |
158 | { |
159 | int i, rc; | |
160 | ||
161 | for (i = 0; i < NR_CPUS; i++) { | |
162 | rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL); | |
4560a294 JF |
163 | if (rc >= 0) { |
164 | num_processors++; | |
f87e4cac | 165 | cpu_set(i, cpu_possible_map); |
4560a294 | 166 | } |
f87e4cac JF |
167 | } |
168 | } | |
169 | ||
a9e7062d | 170 | static void __init xen_smp_prepare_boot_cpu(void) |
f87e4cac | 171 | { |
f87e4cac JF |
172 | BUG_ON(smp_processor_id() != 0); |
173 | native_smp_prepare_boot_cpu(); | |
174 | ||
f87e4cac JF |
175 | /* We've switched to the "real" per-cpu gdt, so make sure the |
176 | old memory can be recycled */ | |
c7b75947 | 177 | make_lowmem_page_readwrite(&per_cpu_var(gdt_page)); |
60223a32 JF |
178 | |
179 | xen_setup_vcpu_info_placement(); | |
f87e4cac JF |
180 | } |
181 | ||
a9e7062d | 182 | static void __init xen_smp_prepare_cpus(unsigned int max_cpus) |
f87e4cac JF |
183 | { |
184 | unsigned cpu; | |
185 | ||
2d9e1e2f JF |
186 | xen_init_lock_cpu(0); |
187 | ||
f87e4cac | 188 | smp_store_cpu_info(0); |
c7b75947 | 189 | cpu_data(0).x86_max_cores = 1; |
f87e4cac JF |
190 | set_cpu_sibling_map(0); |
191 | ||
192 | if (xen_smp_intr_init(0)) | |
193 | BUG(); | |
194 | ||
ecaa6c9d | 195 | xen_cpu_initialized_map = cpumask_of_cpu(0); |
f87e4cac JF |
196 | |
197 | /* Restrict the possible_map according to max_cpus. */ | |
198 | while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) { | |
7c04e64a | 199 | for (cpu = NR_CPUS - 1; !cpu_possible(cpu); cpu--) |
f87e4cac JF |
200 | continue; |
201 | cpu_clear(cpu, cpu_possible_map); | |
202 | } | |
203 | ||
204 | for_each_possible_cpu (cpu) { | |
205 | struct task_struct *idle; | |
206 | ||
207 | if (cpu == 0) | |
208 | continue; | |
209 | ||
210 | idle = fork_idle(cpu); | |
211 | if (IS_ERR(idle)) | |
212 | panic("failed fork for CPU %d", cpu); | |
213 | ||
214 | cpu_set(cpu, cpu_present_map); | |
215 | } | |
f87e4cac JF |
216 | } |
217 | ||
218 | static __cpuinit int | |
219 | cpu_initialize_context(unsigned int cpu, struct task_struct *idle) | |
220 | { | |
221 | struct vcpu_guest_context *ctxt; | |
c7b75947 | 222 | struct desc_struct *gdt; |
f87e4cac | 223 | |
ecaa6c9d | 224 | if (cpu_test_and_set(cpu, xen_cpu_initialized_map)) |
f87e4cac JF |
225 | return 0; |
226 | ||
227 | ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL); | |
228 | if (ctxt == NULL) | |
229 | return -ENOMEM; | |
230 | ||
c7b75947 JF |
231 | gdt = get_cpu_gdt_table(cpu); |
232 | ||
f87e4cac JF |
233 | ctxt->flags = VGCF_IN_KERNEL; |
234 | ctxt->user_regs.ds = __USER_DS; | |
235 | ctxt->user_regs.es = __USER_DS; | |
f87e4cac | 236 | ctxt->user_regs.ss = __KERNEL_DS; |
c7b75947 JF |
237 | #ifdef CONFIG_X86_32 |
238 | ctxt->user_regs.fs = __KERNEL_PERCPU; | |
239 | #endif | |
f87e4cac JF |
240 | ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle; |
241 | ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */ | |
242 | ||
243 | memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt)); | |
244 | ||
245 | xen_copy_trap_info(ctxt->trap_ctxt); | |
246 | ||
247 | ctxt->ldt_ents = 0; | |
248 | ||
c7b75947 JF |
249 | BUG_ON((unsigned long)gdt & ~PAGE_MASK); |
250 | make_lowmem_page_readonly(gdt); | |
f87e4cac | 251 | |
c7b75947 JF |
252 | ctxt->gdt_frames[0] = virt_to_mfn(gdt); |
253 | ctxt->gdt_ents = GDT_ENTRIES; | |
f87e4cac JF |
254 | |
255 | ctxt->user_regs.cs = __KERNEL_CS; | |
faca6227 | 256 | ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs); |
f87e4cac JF |
257 | |
258 | ctxt->kernel_ss = __KERNEL_DS; | |
faca6227 | 259 | ctxt->kernel_sp = idle->thread.sp0; |
f87e4cac | 260 | |
c7b75947 | 261 | #ifdef CONFIG_X86_32 |
f87e4cac | 262 | ctxt->event_callback_cs = __KERNEL_CS; |
f87e4cac | 263 | ctxt->failsafe_callback_cs = __KERNEL_CS; |
c7b75947 JF |
264 | #endif |
265 | ctxt->event_callback_eip = (unsigned long)xen_hypervisor_callback; | |
f87e4cac JF |
266 | ctxt->failsafe_callback_eip = (unsigned long)xen_failsafe_callback; |
267 | ||
268 | per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir); | |
269 | ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir)); | |
270 | ||
271 | if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt)) | |
272 | BUG(); | |
273 | ||
274 | kfree(ctxt); | |
275 | return 0; | |
276 | } | |
277 | ||
a9e7062d | 278 | static int __cpuinit xen_cpu_up(unsigned int cpu) |
f87e4cac JF |
279 | { |
280 | struct task_struct *idle = idle_task(cpu); | |
281 | int rc; | |
282 | ||
c7b75947 JF |
283 | #ifdef CONFIG_X86_64 |
284 | /* Allocate node local memory for AP pdas */ | |
285 | WARN_ON(cpu == 0); | |
286 | if (cpu > 0) { | |
287 | rc = get_local_pda(cpu); | |
288 | if (rc) | |
289 | return rc; | |
290 | } | |
291 | #endif | |
292 | ||
293 | #ifdef CONFIG_X86_32 | |
f87e4cac JF |
294 | init_gdt(cpu); |
295 | per_cpu(current_task, cpu) = idle; | |
f87e4cac | 296 | irq_ctx_init(cpu); |
c7b75947 JF |
297 | #else |
298 | cpu_pda(cpu)->pcurrent = idle; | |
299 | clear_tsk_thread_flag(idle, TIF_FORK); | |
300 | #endif | |
f87e4cac | 301 | xen_setup_timer(cpu); |
2d9e1e2f | 302 | xen_init_lock_cpu(cpu); |
f87e4cac | 303 | |
c7b75947 JF |
304 | per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; |
305 | ||
f87e4cac JF |
306 | /* make sure interrupts start blocked */ |
307 | per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1; | |
308 | ||
309 | rc = cpu_initialize_context(cpu, idle); | |
310 | if (rc) | |
311 | return rc; | |
312 | ||
313 | if (num_online_cpus() == 1) | |
314 | alternatives_smp_switch(1); | |
315 | ||
316 | rc = xen_smp_intr_init(cpu); | |
317 | if (rc) | |
318 | return rc; | |
319 | ||
f87e4cac JF |
320 | rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL); |
321 | BUG_ON(rc); | |
322 | ||
c7b75947 JF |
323 | while(per_cpu(cpu_state, cpu) != CPU_ONLINE) { |
324 | HYPERVISOR_sched_op(SCHEDOP_yield, 0); | |
325 | barrier(); | |
326 | } | |
327 | ||
f87e4cac JF |
328 | return 0; |
329 | } | |
330 | ||
a9e7062d | 331 | static void xen_smp_cpus_done(unsigned int max_cpus) |
f87e4cac JF |
332 | { |
333 | } | |
334 | ||
2737146b | 335 | #ifdef CONFIG_HOTPLUG_CPU |
26fd1051 | 336 | static int xen_cpu_disable(void) |
d68d82af AN |
337 | { |
338 | unsigned int cpu = smp_processor_id(); | |
339 | if (cpu == 0) | |
340 | return -EBUSY; | |
341 | ||
342 | cpu_disable_common(); | |
343 | ||
344 | load_cr3(swapper_pg_dir); | |
345 | return 0; | |
346 | } | |
347 | ||
26fd1051 | 348 | static void xen_cpu_die(unsigned int cpu) |
d68d82af AN |
349 | { |
350 | while (HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) { | |
351 | current->state = TASK_UNINTERRUPTIBLE; | |
352 | schedule_timeout(HZ/10); | |
353 | } | |
354 | unbind_from_irqhandler(per_cpu(resched_irq, cpu), NULL); | |
355 | unbind_from_irqhandler(per_cpu(callfunc_irq, cpu), NULL); | |
356 | unbind_from_irqhandler(per_cpu(debug_irq, cpu), NULL); | |
357 | unbind_from_irqhandler(per_cpu(callfuncsingle_irq, cpu), NULL); | |
358 | xen_uninit_lock_cpu(cpu); | |
359 | xen_teardown_timer(cpu); | |
360 | ||
361 | if (num_online_cpus() == 1) | |
362 | alternatives_smp_switch(0); | |
363 | } | |
364 | ||
df6b0794 | 365 | static void __cpuinit xen_play_dead(void) /* used only with CPU_HOTPLUG */ |
d68d82af AN |
366 | { |
367 | play_dead_common(); | |
368 | HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL); | |
369 | cpu_bringup(); | |
370 | } | |
371 | ||
2737146b | 372 | #else /* !CONFIG_HOTPLUG_CPU */ |
26fd1051 | 373 | static int xen_cpu_disable(void) |
2737146b AN |
374 | { |
375 | return -ENOSYS; | |
376 | } | |
377 | ||
26fd1051 | 378 | static void xen_cpu_die(unsigned int cpu) |
2737146b AN |
379 | { |
380 | BUG(); | |
381 | } | |
382 | ||
26fd1051 | 383 | static void xen_play_dead(void) |
2737146b AN |
384 | { |
385 | BUG(); | |
386 | } | |
387 | ||
388 | #endif | |
f87e4cac JF |
389 | static void stop_self(void *v) |
390 | { | |
391 | int cpu = smp_processor_id(); | |
392 | ||
393 | /* make sure we're not pinning something down */ | |
394 | load_cr3(swapper_pg_dir); | |
395 | /* should set up a minimal gdt */ | |
396 | ||
397 | HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL); | |
398 | BUG(); | |
399 | } | |
400 | ||
a9e7062d | 401 | static void xen_smp_send_stop(void) |
f87e4cac | 402 | { |
8691e5a8 | 403 | smp_call_function(stop_self, NULL, 0); |
f87e4cac JF |
404 | } |
405 | ||
a9e7062d | 406 | static void xen_smp_send_reschedule(int cpu) |
f87e4cac JF |
407 | { |
408 | xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR); | |
409 | } | |
410 | ||
f87e4cac JF |
411 | static void xen_send_IPI_mask(cpumask_t mask, enum ipi_vector vector) |
412 | { | |
413 | unsigned cpu; | |
414 | ||
415 | cpus_and(mask, mask, cpu_online_map); | |
416 | ||
334ef7a7 | 417 | for_each_cpu_mask_nr(cpu, mask) |
f87e4cac JF |
418 | xen_send_IPI_one(cpu, vector); |
419 | } | |
420 | ||
a9e7062d | 421 | static void xen_smp_send_call_function_ipi(cpumask_t mask) |
3b16cf87 JA |
422 | { |
423 | int cpu; | |
424 | ||
425 | xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR); | |
426 | ||
427 | /* Make sure other vcpus get a chance to run if they need to. */ | |
82638844 | 428 | for_each_cpu_mask_nr(cpu, mask) { |
3b16cf87 JA |
429 | if (xen_vcpu_stolen(cpu)) { |
430 | HYPERVISOR_sched_op(SCHEDOP_yield, 0); | |
431 | break; | |
432 | } | |
433 | } | |
434 | } | |
435 | ||
a9e7062d | 436 | static void xen_smp_send_call_function_single_ipi(int cpu) |
3b16cf87 JA |
437 | { |
438 | xen_send_IPI_mask(cpumask_of_cpu(cpu), XEN_CALL_FUNCTION_SINGLE_VECTOR); | |
439 | } | |
440 | ||
f87e4cac JF |
441 | static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id) |
442 | { | |
f87e4cac | 443 | irq_enter(); |
3b16cf87 | 444 | generic_smp_call_function_interrupt(); |
c7b75947 | 445 | #ifdef CONFIG_X86_32 |
38e760a1 | 446 | __get_cpu_var(irq_stat).irq_call_count++; |
c7b75947 JF |
447 | #else |
448 | add_pda(irq_call_count, 1); | |
449 | #endif | |
f87e4cac JF |
450 | irq_exit(); |
451 | ||
f87e4cac JF |
452 | return IRQ_HANDLED; |
453 | } | |
454 | ||
3b16cf87 | 455 | static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id) |
f87e4cac | 456 | { |
3b16cf87 JA |
457 | irq_enter(); |
458 | generic_smp_call_function_single_interrupt(); | |
c7b75947 | 459 | #ifdef CONFIG_X86_32 |
3b16cf87 | 460 | __get_cpu_var(irq_stat).irq_call_count++; |
c7b75947 JF |
461 | #else |
462 | add_pda(irq_call_count, 1); | |
463 | #endif | |
3b16cf87 | 464 | irq_exit(); |
f87e4cac | 465 | |
3b16cf87 | 466 | return IRQ_HANDLED; |
f87e4cac | 467 | } |
a9e7062d JF |
468 | |
469 | static const struct smp_ops xen_smp_ops __initdata = { | |
470 | .smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu, | |
471 | .smp_prepare_cpus = xen_smp_prepare_cpus, | |
a9e7062d JF |
472 | .smp_cpus_done = xen_smp_cpus_done, |
473 | ||
d68d82af AN |
474 | .cpu_up = xen_cpu_up, |
475 | .cpu_die = xen_cpu_die, | |
476 | .cpu_disable = xen_cpu_disable, | |
477 | .play_dead = xen_play_dead, | |
478 | ||
a9e7062d JF |
479 | .smp_send_stop = xen_smp_send_stop, |
480 | .smp_send_reschedule = xen_smp_send_reschedule, | |
481 | ||
482 | .send_call_func_ipi = xen_smp_send_call_function_ipi, | |
483 | .send_call_func_single_ipi = xen_smp_send_call_function_single_ipi, | |
484 | }; | |
485 | ||
486 | void __init xen_smp_init(void) | |
487 | { | |
488 | smp_ops = xen_smp_ops; | |
c7b75947 | 489 | xen_fill_possible_map(); |
2d9e1e2f | 490 | xen_init_spinlocks(); |
a9e7062d | 491 | } |