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 | ||
b78936e1 | 36 | cpumask_var_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 | { | |
1b437c8c | 53 | inc_irq_stat(irq_resched_count); |
38bb5ab4 | 54 | |
f87e4cac JF |
55 | return IRQ_HANDLED; |
56 | } | |
57 | ||
d68d82af | 58 | static __cpuinit void cpu_bringup(void) |
f87e4cac JF |
59 | { |
60 | int cpu = smp_processor_id(); | |
61 | ||
62 | cpu_init(); | |
d68d82af | 63 | touch_softlockup_watchdog(); |
c7b75947 JF |
64 | preempt_disable(); |
65 | ||
e2a81baf | 66 | xen_enable_sysenter(); |
6fcac6d3 | 67 | xen_enable_syscall(); |
f87e4cac | 68 | |
c7b75947 JF |
69 | cpu = smp_processor_id(); |
70 | smp_store_cpu_info(cpu); | |
71 | cpu_data(cpu).x86_max_cores = 1; | |
72 | set_cpu_sibling_map(cpu); | |
f87e4cac JF |
73 | |
74 | xen_setup_cpu_clockevents(); | |
75 | ||
c7b75947 | 76 | cpu_set(cpu, cpu_online_map); |
6dbde353 | 77 | percpu_write(cpu_state, CPU_ONLINE); |
c7b75947 JF |
78 | wmb(); |
79 | ||
f87e4cac JF |
80 | /* We can take interrupts now: we're officially "up". */ |
81 | local_irq_enable(); | |
82 | ||
83 | wmb(); /* make sure everything is out */ | |
d68d82af AN |
84 | } |
85 | ||
86 | static __cpuinit void cpu_bringup_and_idle(void) | |
87 | { | |
88 | cpu_bringup(); | |
f87e4cac JF |
89 | cpu_idle(); |
90 | } | |
91 | ||
92 | static int xen_smp_intr_init(unsigned int cpu) | |
93 | { | |
94 | int rc; | |
ee523ca1 | 95 | const char *resched_name, *callfunc_name, *debug_name; |
f87e4cac JF |
96 | |
97 | resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu); | |
98 | rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR, | |
99 | cpu, | |
100 | xen_reschedule_interrupt, | |
101 | IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, | |
102 | resched_name, | |
103 | NULL); | |
104 | if (rc < 0) | |
105 | goto fail; | |
106 | per_cpu(resched_irq, cpu) = rc; | |
107 | ||
108 | callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu); | |
109 | rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR, | |
110 | cpu, | |
111 | xen_call_function_interrupt, | |
112 | IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, | |
113 | callfunc_name, | |
114 | NULL); | |
115 | if (rc < 0) | |
116 | goto fail; | |
117 | per_cpu(callfunc_irq, cpu) = rc; | |
118 | ||
ee523ca1 JF |
119 | debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu); |
120 | rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt, | |
121 | IRQF_DISABLED | IRQF_PERCPU | IRQF_NOBALANCING, | |
122 | debug_name, NULL); | |
123 | if (rc < 0) | |
124 | goto fail; | |
125 | per_cpu(debug_irq, cpu) = rc; | |
126 | ||
3b16cf87 JA |
127 | callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu); |
128 | rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR, | |
129 | cpu, | |
130 | xen_call_function_single_interrupt, | |
131 | IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, | |
132 | callfunc_name, | |
133 | NULL); | |
134 | if (rc < 0) | |
135 | goto fail; | |
136 | per_cpu(callfuncsingle_irq, cpu) = rc; | |
137 | ||
f87e4cac JF |
138 | return 0; |
139 | ||
140 | fail: | |
141 | if (per_cpu(resched_irq, cpu) >= 0) | |
142 | unbind_from_irqhandler(per_cpu(resched_irq, cpu), NULL); | |
143 | if (per_cpu(callfunc_irq, cpu) >= 0) | |
144 | unbind_from_irqhandler(per_cpu(callfunc_irq, cpu), NULL); | |
ee523ca1 JF |
145 | if (per_cpu(debug_irq, cpu) >= 0) |
146 | unbind_from_irqhandler(per_cpu(debug_irq, cpu), NULL); | |
3b16cf87 JA |
147 | if (per_cpu(callfuncsingle_irq, cpu) >= 0) |
148 | unbind_from_irqhandler(per_cpu(callfuncsingle_irq, cpu), NULL); | |
149 | ||
f87e4cac JF |
150 | return rc; |
151 | } | |
152 | ||
c7b75947 | 153 | static void __init xen_fill_possible_map(void) |
f87e4cac JF |
154 | { |
155 | int i, rc; | |
156 | ||
e7986739 | 157 | for (i = 0; i < nr_cpu_ids; i++) { |
f87e4cac | 158 | rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL); |
4560a294 JF |
159 | if (rc >= 0) { |
160 | num_processors++; | |
f87e4cac | 161 | cpu_set(i, cpu_possible_map); |
4560a294 | 162 | } |
f87e4cac JF |
163 | } |
164 | } | |
165 | ||
a9e7062d | 166 | static void __init xen_smp_prepare_boot_cpu(void) |
f87e4cac | 167 | { |
f87e4cac JF |
168 | BUG_ON(smp_processor_id() != 0); |
169 | native_smp_prepare_boot_cpu(); | |
170 | ||
f87e4cac JF |
171 | /* We've switched to the "real" per-cpu gdt, so make sure the |
172 | old memory can be recycled */ | |
38341432 | 173 | make_lowmem_page_readwrite(xen_initial_gdt); |
60223a32 JF |
174 | |
175 | xen_setup_vcpu_info_placement(); | |
f87e4cac JF |
176 | } |
177 | ||
a9e7062d | 178 | static void __init xen_smp_prepare_cpus(unsigned int max_cpus) |
f87e4cac JF |
179 | { |
180 | unsigned cpu; | |
181 | ||
2d9e1e2f JF |
182 | xen_init_lock_cpu(0); |
183 | ||
f87e4cac | 184 | smp_store_cpu_info(0); |
c7b75947 | 185 | cpu_data(0).x86_max_cores = 1; |
f87e4cac JF |
186 | set_cpu_sibling_map(0); |
187 | ||
188 | if (xen_smp_intr_init(0)) | |
189 | BUG(); | |
190 | ||
b78936e1 MT |
191 | if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL)) |
192 | panic("could not allocate xen_cpu_initialized_map\n"); | |
193 | ||
194 | cpumask_copy(xen_cpu_initialized_map, cpumask_of(0)); | |
f87e4cac JF |
195 | |
196 | /* Restrict the possible_map according to max_cpus. */ | |
197 | while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) { | |
e7986739 | 198 | for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--) |
f87e4cac JF |
199 | continue; |
200 | cpu_clear(cpu, cpu_possible_map); | |
201 | } | |
202 | ||
203 | for_each_possible_cpu (cpu) { | |
204 | struct task_struct *idle; | |
205 | ||
206 | if (cpu == 0) | |
207 | continue; | |
208 | ||
209 | idle = fork_idle(cpu); | |
210 | if (IS_ERR(idle)) | |
211 | panic("failed fork for CPU %d", cpu); | |
212 | ||
213 | cpu_set(cpu, cpu_present_map); | |
214 | } | |
f87e4cac JF |
215 | } |
216 | ||
217 | static __cpuinit int | |
218 | cpu_initialize_context(unsigned int cpu, struct task_struct *idle) | |
219 | { | |
220 | struct vcpu_guest_context *ctxt; | |
c7b75947 | 221 | struct desc_struct *gdt; |
9976b39b | 222 | unsigned long gdt_mfn; |
f87e4cac | 223 | |
b78936e1 | 224 | if (cpumask_test_and_set_cpu(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; | |
795f99b6 JF |
239 | #else |
240 | ctxt->gs_base_kernel = per_cpu_offset(cpu); | |
c7b75947 | 241 | #endif |
f87e4cac JF |
242 | ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle; |
243 | ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */ | |
244 | ||
245 | memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt)); | |
246 | ||
247 | xen_copy_trap_info(ctxt->trap_ctxt); | |
248 | ||
249 | ctxt->ldt_ents = 0; | |
250 | ||
c7b75947 | 251 | BUG_ON((unsigned long)gdt & ~PAGE_MASK); |
9976b39b JF |
252 | |
253 | gdt_mfn = arbitrary_virt_to_mfn(gdt); | |
c7b75947 | 254 | make_lowmem_page_readonly(gdt); |
9976b39b | 255 | make_lowmem_page_readonly(mfn_to_virt(gdt_mfn)); |
f87e4cac | 256 | |
9976b39b | 257 | ctxt->gdt_frames[0] = gdt_mfn; |
c7b75947 | 258 | ctxt->gdt_ents = GDT_ENTRIES; |
f87e4cac JF |
259 | |
260 | ctxt->user_regs.cs = __KERNEL_CS; | |
faca6227 | 261 | ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs); |
f87e4cac JF |
262 | |
263 | ctxt->kernel_ss = __KERNEL_DS; | |
faca6227 | 264 | ctxt->kernel_sp = idle->thread.sp0; |
f87e4cac | 265 | |
c7b75947 | 266 | #ifdef CONFIG_X86_32 |
f87e4cac | 267 | ctxt->event_callback_cs = __KERNEL_CS; |
f87e4cac | 268 | ctxt->failsafe_callback_cs = __KERNEL_CS; |
c7b75947 JF |
269 | #endif |
270 | ctxt->event_callback_eip = (unsigned long)xen_hypervisor_callback; | |
f87e4cac JF |
271 | ctxt->failsafe_callback_eip = (unsigned long)xen_failsafe_callback; |
272 | ||
273 | per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir); | |
274 | ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir)); | |
275 | ||
276 | if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt)) | |
277 | BUG(); | |
278 | ||
279 | kfree(ctxt); | |
280 | return 0; | |
281 | } | |
282 | ||
a9e7062d | 283 | static int __cpuinit xen_cpu_up(unsigned int cpu) |
f87e4cac JF |
284 | { |
285 | struct task_struct *idle = idle_task(cpu); | |
286 | int rc; | |
287 | ||
c6f5e0ac | 288 | per_cpu(current_task, cpu) = idle; |
c7b75947 | 289 | #ifdef CONFIG_X86_32 |
f87e4cac | 290 | irq_ctx_init(cpu); |
c7b75947 | 291 | #else |
c7b75947 | 292 | clear_tsk_thread_flag(idle, TIF_FORK); |
38341432 JF |
293 | per_cpu(kernel_stack, cpu) = |
294 | (unsigned long)task_stack_page(idle) - | |
295 | KERNEL_STACK_OFFSET + THREAD_SIZE; | |
c7b75947 | 296 | #endif |
f87e4cac | 297 | xen_setup_timer(cpu); |
2d9e1e2f | 298 | xen_init_lock_cpu(cpu); |
f87e4cac | 299 | |
c7b75947 JF |
300 | per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; |
301 | ||
f87e4cac JF |
302 | /* make sure interrupts start blocked */ |
303 | per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1; | |
304 | ||
305 | rc = cpu_initialize_context(cpu, idle); | |
306 | if (rc) | |
307 | return rc; | |
308 | ||
309 | if (num_online_cpus() == 1) | |
310 | alternatives_smp_switch(1); | |
311 | ||
312 | rc = xen_smp_intr_init(cpu); | |
313 | if (rc) | |
314 | return rc; | |
315 | ||
f87e4cac JF |
316 | rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL); |
317 | BUG_ON(rc); | |
318 | ||
c7b75947 JF |
319 | while(per_cpu(cpu_state, cpu) != CPU_ONLINE) { |
320 | HYPERVISOR_sched_op(SCHEDOP_yield, 0); | |
321 | barrier(); | |
322 | } | |
323 | ||
f87e4cac JF |
324 | return 0; |
325 | } | |
326 | ||
a9e7062d | 327 | static void xen_smp_cpus_done(unsigned int max_cpus) |
f87e4cac JF |
328 | { |
329 | } | |
330 | ||
2737146b | 331 | #ifdef CONFIG_HOTPLUG_CPU |
26fd1051 | 332 | static int xen_cpu_disable(void) |
d68d82af AN |
333 | { |
334 | unsigned int cpu = smp_processor_id(); | |
335 | if (cpu == 0) | |
336 | return -EBUSY; | |
337 | ||
338 | cpu_disable_common(); | |
339 | ||
340 | load_cr3(swapper_pg_dir); | |
341 | return 0; | |
342 | } | |
343 | ||
26fd1051 | 344 | static void xen_cpu_die(unsigned int cpu) |
d68d82af AN |
345 | { |
346 | while (HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) { | |
347 | current->state = TASK_UNINTERRUPTIBLE; | |
348 | schedule_timeout(HZ/10); | |
349 | } | |
350 | unbind_from_irqhandler(per_cpu(resched_irq, cpu), NULL); | |
351 | unbind_from_irqhandler(per_cpu(callfunc_irq, cpu), NULL); | |
352 | unbind_from_irqhandler(per_cpu(debug_irq, cpu), NULL); | |
353 | unbind_from_irqhandler(per_cpu(callfuncsingle_irq, cpu), NULL); | |
354 | xen_uninit_lock_cpu(cpu); | |
355 | xen_teardown_timer(cpu); | |
356 | ||
357 | if (num_online_cpus() == 1) | |
358 | alternatives_smp_switch(0); | |
359 | } | |
360 | ||
df6b0794 | 361 | static void __cpuinit xen_play_dead(void) /* used only with CPU_HOTPLUG */ |
d68d82af AN |
362 | { |
363 | play_dead_common(); | |
364 | HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL); | |
365 | cpu_bringup(); | |
366 | } | |
367 | ||
2737146b | 368 | #else /* !CONFIG_HOTPLUG_CPU */ |
26fd1051 | 369 | static int xen_cpu_disable(void) |
2737146b AN |
370 | { |
371 | return -ENOSYS; | |
372 | } | |
373 | ||
26fd1051 | 374 | static void xen_cpu_die(unsigned int cpu) |
2737146b AN |
375 | { |
376 | BUG(); | |
377 | } | |
378 | ||
26fd1051 | 379 | static void xen_play_dead(void) |
2737146b AN |
380 | { |
381 | BUG(); | |
382 | } | |
383 | ||
384 | #endif | |
f87e4cac JF |
385 | static void stop_self(void *v) |
386 | { | |
387 | int cpu = smp_processor_id(); | |
388 | ||
389 | /* make sure we're not pinning something down */ | |
390 | load_cr3(swapper_pg_dir); | |
391 | /* should set up a minimal gdt */ | |
392 | ||
393 | HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL); | |
394 | BUG(); | |
395 | } | |
396 | ||
a9e7062d | 397 | static void xen_smp_send_stop(void) |
f87e4cac | 398 | { |
8691e5a8 | 399 | smp_call_function(stop_self, NULL, 0); |
f87e4cac JF |
400 | } |
401 | ||
a9e7062d | 402 | static void xen_smp_send_reschedule(int cpu) |
f87e4cac JF |
403 | { |
404 | xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR); | |
405 | } | |
406 | ||
bcda016e MT |
407 | static void xen_send_IPI_mask(const struct cpumask *mask, |
408 | enum ipi_vector vector) | |
f87e4cac JF |
409 | { |
410 | unsigned cpu; | |
411 | ||
bcda016e | 412 | for_each_cpu_and(cpu, mask, cpu_online_mask) |
f87e4cac JF |
413 | xen_send_IPI_one(cpu, vector); |
414 | } | |
415 | ||
bcda016e | 416 | static void xen_smp_send_call_function_ipi(const struct cpumask *mask) |
3b16cf87 JA |
417 | { |
418 | int cpu; | |
419 | ||
420 | xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR); | |
421 | ||
422 | /* Make sure other vcpus get a chance to run if they need to. */ | |
bcda016e | 423 | for_each_cpu(cpu, mask) { |
3b16cf87 JA |
424 | if (xen_vcpu_stolen(cpu)) { |
425 | HYPERVISOR_sched_op(SCHEDOP_yield, 0); | |
426 | break; | |
427 | } | |
428 | } | |
429 | } | |
430 | ||
a9e7062d | 431 | static void xen_smp_send_call_function_single_ipi(int cpu) |
3b16cf87 | 432 | { |
bcda016e | 433 | xen_send_IPI_mask(cpumask_of(cpu), |
e7986739 | 434 | XEN_CALL_FUNCTION_SINGLE_VECTOR); |
3b16cf87 JA |
435 | } |
436 | ||
f87e4cac JF |
437 | static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id) |
438 | { | |
f87e4cac | 439 | irq_enter(); |
3b16cf87 | 440 | generic_smp_call_function_interrupt(); |
1b437c8c | 441 | inc_irq_stat(irq_call_count); |
f87e4cac JF |
442 | irq_exit(); |
443 | ||
f87e4cac JF |
444 | return IRQ_HANDLED; |
445 | } | |
446 | ||
3b16cf87 | 447 | static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id) |
f87e4cac | 448 | { |
3b16cf87 JA |
449 | irq_enter(); |
450 | generic_smp_call_function_single_interrupt(); | |
1b437c8c | 451 | inc_irq_stat(irq_call_count); |
3b16cf87 | 452 | irq_exit(); |
f87e4cac | 453 | |
3b16cf87 | 454 | return IRQ_HANDLED; |
f87e4cac | 455 | } |
a9e7062d JF |
456 | |
457 | static const struct smp_ops xen_smp_ops __initdata = { | |
458 | .smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu, | |
459 | .smp_prepare_cpus = xen_smp_prepare_cpus, | |
a9e7062d JF |
460 | .smp_cpus_done = xen_smp_cpus_done, |
461 | ||
d68d82af AN |
462 | .cpu_up = xen_cpu_up, |
463 | .cpu_die = xen_cpu_die, | |
464 | .cpu_disable = xen_cpu_disable, | |
465 | .play_dead = xen_play_dead, | |
466 | ||
a9e7062d JF |
467 | .smp_send_stop = xen_smp_send_stop, |
468 | .smp_send_reschedule = xen_smp_send_reschedule, | |
469 | ||
470 | .send_call_func_ipi = xen_smp_send_call_function_ipi, | |
471 | .send_call_func_single_ipi = xen_smp_send_call_function_single_ipi, | |
472 | }; | |
473 | ||
474 | void __init xen_smp_init(void) | |
475 | { | |
476 | smp_ops = xen_smp_ops; | |
c7b75947 | 477 | xen_fill_possible_map(); |
2d9e1e2f | 478 | xen_init_spinlocks(); |
a9e7062d | 479 | } |