IB/srp: Let srp_abort() return FAST_IO_FAIL if TL offline
[linux/fpc-iii.git] / arch / x86 / xen / smp.c
blobd99cae8147d1243b84faa111bcd74b447e5ff7ec
1 /*
2 * Xen SMP support
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.
8 * IPIs are handled through the Xen event mechanism.
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.
15 #include <linux/sched.h>
16 #include <linux/err.h>
17 #include <linux/slab.h>
18 #include <linux/smp.h>
19 #include <linux/irq_work.h>
20 #include <linux/tick.h>
22 #include <asm/paravirt.h>
23 #include <asm/desc.h>
24 #include <asm/pgtable.h>
25 #include <asm/cpu.h>
27 #include <xen/interface/xen.h>
28 #include <xen/interface/vcpu.h>
30 #include <asm/xen/interface.h>
31 #include <asm/xen/hypercall.h>
33 #include <xen/xen.h>
34 #include <xen/page.h>
35 #include <xen/events.h>
37 #include <xen/hvc-console.h>
38 #include "xen-ops.h"
39 #include "mmu.h"
41 cpumask_var_t xen_cpu_initialized_map;
43 static DEFINE_PER_CPU(int, xen_resched_irq);
44 static DEFINE_PER_CPU(int, xen_callfunc_irq);
45 static DEFINE_PER_CPU(int, xen_callfuncsingle_irq);
46 static DEFINE_PER_CPU(int, xen_irq_work);
47 static DEFINE_PER_CPU(int, xen_debug_irq) = -1;
49 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
50 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
51 static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id);
54 * Reschedule call back.
56 static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
58 inc_irq_stat(irq_resched_count);
59 scheduler_ipi();
61 return IRQ_HANDLED;
64 static void __cpuinit cpu_bringup(void)
66 int cpu;
68 cpu_init();
69 touch_softlockup_watchdog();
70 preempt_disable();
72 xen_enable_sysenter();
73 xen_enable_syscall();
75 cpu = smp_processor_id();
76 smp_store_cpu_info(cpu);
77 cpu_data(cpu).x86_max_cores = 1;
78 set_cpu_sibling_map(cpu);
80 xen_setup_cpu_clockevents();
82 notify_cpu_starting(cpu);
84 set_cpu_online(cpu, true);
86 this_cpu_write(cpu_state, CPU_ONLINE);
88 wmb();
90 /* We can take interrupts now: we're officially "up". */
91 local_irq_enable();
93 wmb(); /* make sure everything is out */
96 static void __cpuinit cpu_bringup_and_idle(void)
98 cpu_bringup();
99 cpu_startup_entry(CPUHP_ONLINE);
102 static int xen_smp_intr_init(unsigned int cpu)
104 int rc;
105 const char *resched_name, *callfunc_name, *debug_name;
107 resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
108 rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
109 cpu,
110 xen_reschedule_interrupt,
111 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
112 resched_name,
113 NULL);
114 if (rc < 0)
115 goto fail;
116 per_cpu(xen_resched_irq, cpu) = rc;
118 callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
119 rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
120 cpu,
121 xen_call_function_interrupt,
122 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
123 callfunc_name,
124 NULL);
125 if (rc < 0)
126 goto fail;
127 per_cpu(xen_callfunc_irq, cpu) = rc;
129 debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
130 rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
131 IRQF_DISABLED | IRQF_PERCPU | IRQF_NOBALANCING,
132 debug_name, NULL);
133 if (rc < 0)
134 goto fail;
135 per_cpu(xen_debug_irq, cpu) = rc;
137 callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
138 rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
139 cpu,
140 xen_call_function_single_interrupt,
141 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
142 callfunc_name,
143 NULL);
144 if (rc < 0)
145 goto fail;
146 per_cpu(xen_callfuncsingle_irq, cpu) = rc;
149 * The IRQ worker on PVHVM goes through the native path and uses the
150 * IPI mechanism.
152 if (xen_hvm_domain())
153 return 0;
155 callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu);
156 rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR,
157 cpu,
158 xen_irq_work_interrupt,
159 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
160 callfunc_name,
161 NULL);
162 if (rc < 0)
163 goto fail;
164 per_cpu(xen_irq_work, cpu) = rc;
166 return 0;
168 fail:
169 if (per_cpu(xen_resched_irq, cpu) >= 0)
170 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
171 if (per_cpu(xen_callfunc_irq, cpu) >= 0)
172 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
173 if (per_cpu(xen_debug_irq, cpu) >= 0)
174 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
175 if (per_cpu(xen_callfuncsingle_irq, cpu) >= 0)
176 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu),
177 NULL);
178 if (xen_hvm_domain())
179 return rc;
181 if (per_cpu(xen_irq_work, cpu) >= 0)
182 unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL);
184 return rc;
187 static void __init xen_fill_possible_map(void)
189 int i, rc;
191 if (xen_initial_domain())
192 return;
194 for (i = 0; i < nr_cpu_ids; i++) {
195 rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
196 if (rc >= 0) {
197 num_processors++;
198 set_cpu_possible(i, true);
203 static void __init xen_filter_cpu_maps(void)
205 int i, rc;
206 unsigned int subtract = 0;
208 if (!xen_initial_domain())
209 return;
211 num_processors = 0;
212 disabled_cpus = 0;
213 for (i = 0; i < nr_cpu_ids; i++) {
214 rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
215 if (rc >= 0) {
216 num_processors++;
217 set_cpu_possible(i, true);
218 } else {
219 set_cpu_possible(i, false);
220 set_cpu_present(i, false);
221 subtract++;
224 #ifdef CONFIG_HOTPLUG_CPU
225 /* This is akin to using 'nr_cpus' on the Linux command line.
226 * Which is OK as when we use 'dom0_max_vcpus=X' we can only
227 * have up to X, while nr_cpu_ids is greater than X. This
228 * normally is not a problem, except when CPU hotplugging
229 * is involved and then there might be more than X CPUs
230 * in the guest - which will not work as there is no
231 * hypercall to expand the max number of VCPUs an already
232 * running guest has. So cap it up to X. */
233 if (subtract)
234 nr_cpu_ids = nr_cpu_ids - subtract;
235 #endif
239 static void __init xen_smp_prepare_boot_cpu(void)
241 BUG_ON(smp_processor_id() != 0);
242 native_smp_prepare_boot_cpu();
244 /* We've switched to the "real" per-cpu gdt, so make sure the
245 old memory can be recycled */
246 make_lowmem_page_readwrite(xen_initial_gdt);
248 xen_filter_cpu_maps();
249 xen_setup_vcpu_info_placement();
252 static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
254 unsigned cpu;
255 unsigned int i;
257 if (skip_ioapic_setup) {
258 char *m = (max_cpus == 0) ?
259 "The nosmp parameter is incompatible with Xen; " \
260 "use Xen dom0_max_vcpus=1 parameter" :
261 "The noapic parameter is incompatible with Xen";
263 xen_raw_printk(m);
264 panic(m);
266 xen_init_lock_cpu(0);
268 smp_store_boot_cpu_info();
269 cpu_data(0).x86_max_cores = 1;
271 for_each_possible_cpu(i) {
272 zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
273 zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
274 zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
276 set_cpu_sibling_map(0);
278 if (xen_smp_intr_init(0))
279 BUG();
281 if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL))
282 panic("could not allocate xen_cpu_initialized_map\n");
284 cpumask_copy(xen_cpu_initialized_map, cpumask_of(0));
286 /* Restrict the possible_map according to max_cpus. */
287 while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
288 for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--)
289 continue;
290 set_cpu_possible(cpu, false);
293 for_each_possible_cpu(cpu)
294 set_cpu_present(cpu, true);
297 static int __cpuinit
298 cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
300 struct vcpu_guest_context *ctxt;
301 struct desc_struct *gdt;
302 unsigned long gdt_mfn;
304 if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
305 return 0;
307 ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
308 if (ctxt == NULL)
309 return -ENOMEM;
311 gdt = get_cpu_gdt_table(cpu);
313 ctxt->flags = VGCF_IN_KERNEL;
314 ctxt->user_regs.ss = __KERNEL_DS;
315 #ifdef CONFIG_X86_32
316 ctxt->user_regs.fs = __KERNEL_PERCPU;
317 ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
318 #else
319 ctxt->gs_base_kernel = per_cpu_offset(cpu);
320 #endif
321 ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
323 memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
326 ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
327 ctxt->user_regs.ds = __USER_DS;
328 ctxt->user_regs.es = __USER_DS;
330 xen_copy_trap_info(ctxt->trap_ctxt);
332 ctxt->ldt_ents = 0;
334 BUG_ON((unsigned long)gdt & ~PAGE_MASK);
336 gdt_mfn = arbitrary_virt_to_mfn(gdt);
337 make_lowmem_page_readonly(gdt);
338 make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
340 ctxt->gdt_frames[0] = gdt_mfn;
341 ctxt->gdt_ents = GDT_ENTRIES;
343 ctxt->kernel_ss = __KERNEL_DS;
344 ctxt->kernel_sp = idle->thread.sp0;
346 #ifdef CONFIG_X86_32
347 ctxt->event_callback_cs = __KERNEL_CS;
348 ctxt->failsafe_callback_cs = __KERNEL_CS;
349 #endif
350 ctxt->event_callback_eip =
351 (unsigned long)xen_hypervisor_callback;
352 ctxt->failsafe_callback_eip =
353 (unsigned long)xen_failsafe_callback;
355 ctxt->user_regs.cs = __KERNEL_CS;
356 ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
358 per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
359 ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
361 if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
362 BUG();
364 kfree(ctxt);
365 return 0;
368 static int __cpuinit xen_cpu_up(unsigned int cpu, struct task_struct *idle)
370 int rc;
372 per_cpu(current_task, cpu) = idle;
373 #ifdef CONFIG_X86_32
374 irq_ctx_init(cpu);
375 #else
376 clear_tsk_thread_flag(idle, TIF_FORK);
377 per_cpu(kernel_stack, cpu) =
378 (unsigned long)task_stack_page(idle) -
379 KERNEL_STACK_OFFSET + THREAD_SIZE;
380 #endif
381 xen_setup_runstate_info(cpu);
382 xen_setup_timer(cpu);
383 xen_init_lock_cpu(cpu);
385 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
387 /* make sure interrupts start blocked */
388 per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
390 rc = cpu_initialize_context(cpu, idle);
391 if (rc)
392 return rc;
394 if (num_online_cpus() == 1)
395 /* Just in case we booted with a single CPU. */
396 alternatives_enable_smp();
398 rc = xen_smp_intr_init(cpu);
399 if (rc)
400 return rc;
402 rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
403 BUG_ON(rc);
405 while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
406 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
407 barrier();
410 return 0;
413 static void xen_smp_cpus_done(unsigned int max_cpus)
417 #ifdef CONFIG_HOTPLUG_CPU
418 static int xen_cpu_disable(void)
420 unsigned int cpu = smp_processor_id();
421 if (cpu == 0)
422 return -EBUSY;
424 cpu_disable_common();
426 load_cr3(swapper_pg_dir);
427 return 0;
430 static void xen_cpu_die(unsigned int cpu)
432 while (xen_pv_domain() && HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
433 current->state = TASK_UNINTERRUPTIBLE;
434 schedule_timeout(HZ/10);
436 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
437 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
438 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
439 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), NULL);
440 if (!xen_hvm_domain())
441 unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL);
442 xen_uninit_lock_cpu(cpu);
443 xen_teardown_timer(cpu);
446 static void __cpuinit xen_play_dead(void) /* used only with HOTPLUG_CPU */
448 play_dead_common();
449 HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
450 cpu_bringup();
452 * commit 4b0c0f294 (tick: Cleanup NOHZ per cpu data on cpu down)
453 * clears certain data that the cpu_idle loop (which called us
454 * and that we return from) expects. The only way to get that
455 * data back is to call:
457 tick_nohz_idle_enter();
460 #else /* !CONFIG_HOTPLUG_CPU */
461 static int xen_cpu_disable(void)
463 return -ENOSYS;
466 static void xen_cpu_die(unsigned int cpu)
468 BUG();
471 static void xen_play_dead(void)
473 BUG();
476 #endif
477 static void stop_self(void *v)
479 int cpu = smp_processor_id();
481 /* make sure we're not pinning something down */
482 load_cr3(swapper_pg_dir);
483 /* should set up a minimal gdt */
485 set_cpu_online(cpu, false);
487 HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
488 BUG();
491 static void xen_stop_other_cpus(int wait)
493 smp_call_function(stop_self, NULL, wait);
496 static void xen_smp_send_reschedule(int cpu)
498 xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
501 static void __xen_send_IPI_mask(const struct cpumask *mask,
502 int vector)
504 unsigned cpu;
506 for_each_cpu_and(cpu, mask, cpu_online_mask)
507 xen_send_IPI_one(cpu, vector);
510 static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
512 int cpu;
514 __xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
516 /* Make sure other vcpus get a chance to run if they need to. */
517 for_each_cpu(cpu, mask) {
518 if (xen_vcpu_stolen(cpu)) {
519 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
520 break;
525 static void xen_smp_send_call_function_single_ipi(int cpu)
527 __xen_send_IPI_mask(cpumask_of(cpu),
528 XEN_CALL_FUNCTION_SINGLE_VECTOR);
531 static inline int xen_map_vector(int vector)
533 int xen_vector;
535 switch (vector) {
536 case RESCHEDULE_VECTOR:
537 xen_vector = XEN_RESCHEDULE_VECTOR;
538 break;
539 case CALL_FUNCTION_VECTOR:
540 xen_vector = XEN_CALL_FUNCTION_VECTOR;
541 break;
542 case CALL_FUNCTION_SINGLE_VECTOR:
543 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
544 break;
545 case IRQ_WORK_VECTOR:
546 xen_vector = XEN_IRQ_WORK_VECTOR;
547 break;
548 default:
549 xen_vector = -1;
550 printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
551 vector);
554 return xen_vector;
557 void xen_send_IPI_mask(const struct cpumask *mask,
558 int vector)
560 int xen_vector = xen_map_vector(vector);
562 if (xen_vector >= 0)
563 __xen_send_IPI_mask(mask, xen_vector);
566 void xen_send_IPI_all(int vector)
568 int xen_vector = xen_map_vector(vector);
570 if (xen_vector >= 0)
571 __xen_send_IPI_mask(cpu_online_mask, xen_vector);
574 void xen_send_IPI_self(int vector)
576 int xen_vector = xen_map_vector(vector);
578 if (xen_vector >= 0)
579 xen_send_IPI_one(smp_processor_id(), xen_vector);
582 void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
583 int vector)
585 unsigned cpu;
586 unsigned int this_cpu = smp_processor_id();
587 int xen_vector = xen_map_vector(vector);
589 if (!(num_online_cpus() > 1) || (xen_vector < 0))
590 return;
592 for_each_cpu_and(cpu, mask, cpu_online_mask) {
593 if (this_cpu == cpu)
594 continue;
596 xen_send_IPI_one(cpu, xen_vector);
600 void xen_send_IPI_allbutself(int vector)
602 xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
605 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
607 irq_enter();
608 generic_smp_call_function_interrupt();
609 inc_irq_stat(irq_call_count);
610 irq_exit();
612 return IRQ_HANDLED;
615 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
617 irq_enter();
618 generic_smp_call_function_single_interrupt();
619 inc_irq_stat(irq_call_count);
620 irq_exit();
622 return IRQ_HANDLED;
625 static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id)
627 irq_enter();
628 irq_work_run();
629 inc_irq_stat(apic_irq_work_irqs);
630 irq_exit();
632 return IRQ_HANDLED;
635 static const struct smp_ops xen_smp_ops __initconst = {
636 .smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
637 .smp_prepare_cpus = xen_smp_prepare_cpus,
638 .smp_cpus_done = xen_smp_cpus_done,
640 .cpu_up = xen_cpu_up,
641 .cpu_die = xen_cpu_die,
642 .cpu_disable = xen_cpu_disable,
643 .play_dead = xen_play_dead,
645 .stop_other_cpus = xen_stop_other_cpus,
646 .smp_send_reschedule = xen_smp_send_reschedule,
648 .send_call_func_ipi = xen_smp_send_call_function_ipi,
649 .send_call_func_single_ipi = xen_smp_send_call_function_single_ipi,
652 void __init xen_smp_init(void)
654 smp_ops = xen_smp_ops;
655 xen_fill_possible_map();
656 xen_init_spinlocks();
659 static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
661 native_smp_prepare_cpus(max_cpus);
662 WARN_ON(xen_smp_intr_init(0));
664 xen_init_lock_cpu(0);
667 static int __cpuinit xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle)
669 int rc;
670 rc = native_cpu_up(cpu, tidle);
671 WARN_ON (xen_smp_intr_init(cpu));
672 return rc;
675 static void xen_hvm_cpu_die(unsigned int cpu)
677 xen_cpu_die(cpu);
678 native_cpu_die(cpu);
681 void __init xen_hvm_smp_init(void)
683 if (!xen_have_vector_callback)
684 return;
685 smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
686 smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
687 smp_ops.cpu_up = xen_hvm_cpu_up;
688 smp_ops.cpu_die = xen_hvm_cpu_die;
689 smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
690 smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;