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1// SPDX-License-Identifier: GPL-2.0
2#include <linux/smp.h>
3#include <linux/cpu.h>
4#include <linux/slab.h>
5#include <linux/cpumask.h>
6#include <linux/percpu.h>
7
8#include <xen/events.h>
9
10#include <xen/hvc-console.h>
11#include "xen-ops.h"
12#include "smp.h"
13
14static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
15static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
16static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
17static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 };
18
19static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
20static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
21
22/*
23 * Reschedule call back.
24 */
25static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
26{
27 inc_irq_stat(irq_resched_count);
28 scheduler_ipi();
29
30 return IRQ_HANDLED;
31}
32
33void xen_smp_intr_free(unsigned int cpu)
34{
35 kfree(per_cpu(xen_resched_irq, cpu).name);
36 per_cpu(xen_resched_irq, cpu).name = NULL;
37 if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
38 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
39 per_cpu(xen_resched_irq, cpu).irq = -1;
40 }
41 kfree(per_cpu(xen_callfunc_irq, cpu).name);
42 per_cpu(xen_callfunc_irq, cpu).name = NULL;
43 if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
44 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
45 per_cpu(xen_callfunc_irq, cpu).irq = -1;
46 }
47 kfree(per_cpu(xen_debug_irq, cpu).name);
48 per_cpu(xen_debug_irq, cpu).name = NULL;
49 if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
50 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
51 per_cpu(xen_debug_irq, cpu).irq = -1;
52 }
53 kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
54 per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
55 if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
56 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
57 NULL);
58 per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
59 }
60}
61
62int xen_smp_intr_init(unsigned int cpu)
63{
64 int rc;
65 char *resched_name, *callfunc_name, *debug_name;
66
67 resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
68 if (!resched_name)
69 goto fail_mem;
70 per_cpu(xen_resched_irq, cpu).name = resched_name;
71 rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
72 cpu,
73 xen_reschedule_interrupt,
74 IRQF_PERCPU|IRQF_NOBALANCING,
75 resched_name,
76 NULL);
77 if (rc < 0)
78 goto fail;
79 per_cpu(xen_resched_irq, cpu).irq = rc;
80
81 callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
82 if (!callfunc_name)
83 goto fail_mem;
84 per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
85 rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
86 cpu,
87 xen_call_function_interrupt,
88 IRQF_PERCPU|IRQF_NOBALANCING,
89 callfunc_name,
90 NULL);
91 if (rc < 0)
92 goto fail;
93 per_cpu(xen_callfunc_irq, cpu).irq = rc;
94
95 if (!xen_fifo_events) {
96 debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
97 if (!debug_name)
98 goto fail_mem;
99
100 per_cpu(xen_debug_irq, cpu).name = debug_name;
101 rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu,
102 xen_debug_interrupt,
103 IRQF_PERCPU | IRQF_NOBALANCING,
104 debug_name, NULL);
105 if (rc < 0)
106 goto fail;
107 per_cpu(xen_debug_irq, cpu).irq = rc;
108 }
109
110 callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
111 if (!callfunc_name)
112 goto fail_mem;
113
114 per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
115 rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
116 cpu,
117 xen_call_function_single_interrupt,
118 IRQF_PERCPU|IRQF_NOBALANCING,
119 callfunc_name,
120 NULL);
121 if (rc < 0)
122 goto fail;
123 per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
124
125 return 0;
126
127 fail_mem:
128 rc = -ENOMEM;
129 fail:
130 xen_smp_intr_free(cpu);
131 return rc;
132}
133
134void __init xen_smp_cpus_done(unsigned int max_cpus)
135{
136 if (xen_hvm_domain())
137 native_smp_cpus_done(max_cpus);
138 else
139 calculate_max_logical_packages();
140}
141
142void xen_smp_send_reschedule(int cpu)
143{
144 xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
145}
146
147static void __xen_send_IPI_mask(const struct cpumask *mask,
148 int vector)
149{
150 unsigned cpu;
151
152 for_each_cpu_and(cpu, mask, cpu_online_mask)
153 xen_send_IPI_one(cpu, vector);
154}
155
156void xen_smp_send_call_function_ipi(const struct cpumask *mask)
157{
158 int cpu;
159
160 __xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
161
162 /* Make sure other vcpus get a chance to run if they need to. */
163 for_each_cpu(cpu, mask) {
164 if (xen_vcpu_stolen(cpu)) {
165 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
166 break;
167 }
168 }
169}
170
171void xen_smp_send_call_function_single_ipi(int cpu)
172{
173 __xen_send_IPI_mask(cpumask_of(cpu),
174 XEN_CALL_FUNCTION_SINGLE_VECTOR);
175}
176
177static inline int xen_map_vector(int vector)
178{
179 int xen_vector;
180
181 switch (vector) {
182 case RESCHEDULE_VECTOR:
183 xen_vector = XEN_RESCHEDULE_VECTOR;
184 break;
185 case CALL_FUNCTION_VECTOR:
186 xen_vector = XEN_CALL_FUNCTION_VECTOR;
187 break;
188 case CALL_FUNCTION_SINGLE_VECTOR:
189 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
190 break;
191 case IRQ_WORK_VECTOR:
192 xen_vector = XEN_IRQ_WORK_VECTOR;
193 break;
194#ifdef CONFIG_X86_64
195 case NMI_VECTOR:
196 case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
197 xen_vector = XEN_NMI_VECTOR;
198 break;
199#endif
200 default:
201 xen_vector = -1;
202 printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
203 vector);
204 }
205
206 return xen_vector;
207}
208
209void xen_send_IPI_mask(const struct cpumask *mask,
210 int vector)
211{
212 int xen_vector = xen_map_vector(vector);
213
214 if (xen_vector >= 0)
215 __xen_send_IPI_mask(mask, xen_vector);
216}
217
218void xen_send_IPI_all(int vector)
219{
220 int xen_vector = xen_map_vector(vector);
221
222 if (xen_vector >= 0)
223 __xen_send_IPI_mask(cpu_online_mask, xen_vector);
224}
225
226void xen_send_IPI_self(int vector)
227{
228 int xen_vector = xen_map_vector(vector);
229
230 if (xen_vector >= 0)
231 xen_send_IPI_one(smp_processor_id(), xen_vector);
232}
233
234void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
235 int vector)
236{
237 unsigned cpu;
238 unsigned int this_cpu = smp_processor_id();
239 int xen_vector = xen_map_vector(vector);
240
241 if (!(num_online_cpus() > 1) || (xen_vector < 0))
242 return;
243
244 for_each_cpu_and(cpu, mask, cpu_online_mask) {
245 if (this_cpu == cpu)
246 continue;
247
248 xen_send_IPI_one(cpu, xen_vector);
249 }
250}
251
252void xen_send_IPI_allbutself(int vector)
253{
254 xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
255}
256
257static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
258{
259 generic_smp_call_function_interrupt();
260 inc_irq_stat(irq_call_count);
261
262 return IRQ_HANDLED;
263}
264
265static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
266{
267 generic_smp_call_function_single_interrupt();
268 inc_irq_stat(irq_call_count);
269
270 return IRQ_HANDLED;
271}
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.
14 */
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
21#include <asm/paravirt.h>
22#include <asm/desc.h>
23#include <asm/pgtable.h>
24#include <asm/cpu.h>
25
26#include <xen/interface/xen.h>
27#include <xen/interface/vcpu.h>
28
29#include <asm/xen/interface.h>
30#include <asm/xen/hypercall.h>
31
32#include <xen/xen.h>
33#include <xen/page.h>
34#include <xen/events.h>
35
36#include <xen/hvc-console.h>
37#include "xen-ops.h"
38#include "mmu.h"
39
40cpumask_var_t xen_cpu_initialized_map;
41
42static DEFINE_PER_CPU(int, xen_resched_irq);
43static DEFINE_PER_CPU(int, xen_callfunc_irq);
44static DEFINE_PER_CPU(int, xen_callfuncsingle_irq);
45static DEFINE_PER_CPU(int, xen_irq_work);
46static DEFINE_PER_CPU(int, xen_debug_irq) = -1;
47
48static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
49static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
50static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id);
51
52/*
53 * Reschedule call back.
54 */
55static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
56{
57 inc_irq_stat(irq_resched_count);
58 scheduler_ipi();
59
60 return IRQ_HANDLED;
61}
62
63static void __cpuinit cpu_bringup(void)
64{
65 int cpu;
66
67 cpu_init();
68 touch_softlockup_watchdog();
69 preempt_disable();
70
71 xen_enable_sysenter();
72 xen_enable_syscall();
73
74 cpu = smp_processor_id();
75 smp_store_cpu_info(cpu);
76 cpu_data(cpu).x86_max_cores = 1;
77 set_cpu_sibling_map(cpu);
78
79 xen_setup_cpu_clockevents();
80
81 notify_cpu_starting(cpu);
82
83 ipi_call_lock();
84 set_cpu_online(cpu, true);
85 ipi_call_unlock();
86
87 this_cpu_write(cpu_state, CPU_ONLINE);
88
89 wmb();
90
91 /* We can take interrupts now: we're officially "up". */
92 local_irq_enable();
93
94 wmb(); /* make sure everything is out */
95}
96
97static void __cpuinit cpu_bringup_and_idle(void)
98{
99 cpu_bringup();
100 cpu_idle();
101}
102
103static int xen_smp_intr_init(unsigned int cpu)
104{
105 int rc;
106 const char *resched_name, *callfunc_name, *debug_name;
107
108 resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
109 rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
110 cpu,
111 xen_reschedule_interrupt,
112 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
113 resched_name,
114 NULL);
115 if (rc < 0)
116 goto fail;
117 per_cpu(xen_resched_irq, cpu) = rc;
118
119 callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
120 rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
121 cpu,
122 xen_call_function_interrupt,
123 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
124 callfunc_name,
125 NULL);
126 if (rc < 0)
127 goto fail;
128 per_cpu(xen_callfunc_irq, cpu) = rc;
129
130 debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
131 rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
132 IRQF_DISABLED | IRQF_PERCPU | IRQF_NOBALANCING,
133 debug_name, NULL);
134 if (rc < 0)
135 goto fail;
136 per_cpu(xen_debug_irq, cpu) = rc;
137
138 callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
139 rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
140 cpu,
141 xen_call_function_single_interrupt,
142 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
143 callfunc_name,
144 NULL);
145 if (rc < 0)
146 goto fail;
147 per_cpu(xen_callfuncsingle_irq, cpu) = rc;
148
149 callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu);
150 rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR,
151 cpu,
152 xen_irq_work_interrupt,
153 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
154 callfunc_name,
155 NULL);
156 if (rc < 0)
157 goto fail;
158 per_cpu(xen_irq_work, cpu) = rc;
159
160 return 0;
161
162 fail:
163 if (per_cpu(xen_resched_irq, cpu) >= 0)
164 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
165 if (per_cpu(xen_callfunc_irq, cpu) >= 0)
166 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
167 if (per_cpu(xen_debug_irq, cpu) >= 0)
168 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
169 if (per_cpu(xen_callfuncsingle_irq, cpu) >= 0)
170 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu),
171 NULL);
172 if (per_cpu(xen_irq_work, cpu) >= 0)
173 unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL);
174
175 return rc;
176}
177
178static void __init xen_fill_possible_map(void)
179{
180 int i, rc;
181
182 if (xen_initial_domain())
183 return;
184
185 for (i = 0; i < nr_cpu_ids; i++) {
186 rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
187 if (rc >= 0) {
188 num_processors++;
189 set_cpu_possible(i, true);
190 }
191 }
192}
193
194static void __init xen_filter_cpu_maps(void)
195{
196 int i, rc;
197 unsigned int subtract = 0;
198
199 if (!xen_initial_domain())
200 return;
201
202 num_processors = 0;
203 disabled_cpus = 0;
204 for (i = 0; i < nr_cpu_ids; i++) {
205 rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
206 if (rc >= 0) {
207 num_processors++;
208 set_cpu_possible(i, true);
209 } else {
210 set_cpu_possible(i, false);
211 set_cpu_present(i, false);
212 subtract++;
213 }
214 }
215#ifdef CONFIG_HOTPLUG_CPU
216 /* This is akin to using 'nr_cpus' on the Linux command line.
217 * Which is OK as when we use 'dom0_max_vcpus=X' we can only
218 * have up to X, while nr_cpu_ids is greater than X. This
219 * normally is not a problem, except when CPU hotplugging
220 * is involved and then there might be more than X CPUs
221 * in the guest - which will not work as there is no
222 * hypercall to expand the max number of VCPUs an already
223 * running guest has. So cap it up to X. */
224 if (subtract)
225 nr_cpu_ids = nr_cpu_ids - subtract;
226#endif
227
228}
229
230static void __init xen_smp_prepare_boot_cpu(void)
231{
232 BUG_ON(smp_processor_id() != 0);
233 native_smp_prepare_boot_cpu();
234
235 /* We've switched to the "real" per-cpu gdt, so make sure the
236 old memory can be recycled */
237 make_lowmem_page_readwrite(xen_initial_gdt);
238
239 xen_filter_cpu_maps();
240 xen_setup_vcpu_info_placement();
241}
242
243static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
244{
245 unsigned cpu;
246 unsigned int i;
247
248 if (skip_ioapic_setup) {
249 char *m = (max_cpus == 0) ?
250 "The nosmp parameter is incompatible with Xen; " \
251 "use Xen dom0_max_vcpus=1 parameter" :
252 "The noapic parameter is incompatible with Xen";
253
254 xen_raw_printk(m);
255 panic(m);
256 }
257 xen_init_lock_cpu(0);
258
259 smp_store_cpu_info(0);
260 cpu_data(0).x86_max_cores = 1;
261
262 for_each_possible_cpu(i) {
263 zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
264 zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
265 zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
266 }
267 set_cpu_sibling_map(0);
268
269 if (xen_smp_intr_init(0))
270 BUG();
271
272 if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL))
273 panic("could not allocate xen_cpu_initialized_map\n");
274
275 cpumask_copy(xen_cpu_initialized_map, cpumask_of(0));
276
277 /* Restrict the possible_map according to max_cpus. */
278 while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
279 for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--)
280 continue;
281 set_cpu_possible(cpu, false);
282 }
283
284 for_each_possible_cpu(cpu)
285 set_cpu_present(cpu, true);
286}
287
288static int __cpuinit
289cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
290{
291 struct vcpu_guest_context *ctxt;
292 struct desc_struct *gdt;
293 unsigned long gdt_mfn;
294
295 if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
296 return 0;
297
298 ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
299 if (ctxt == NULL)
300 return -ENOMEM;
301
302 gdt = get_cpu_gdt_table(cpu);
303
304 ctxt->flags = VGCF_IN_KERNEL;
305 ctxt->user_regs.ds = __USER_DS;
306 ctxt->user_regs.es = __USER_DS;
307 ctxt->user_regs.ss = __KERNEL_DS;
308#ifdef CONFIG_X86_32
309 ctxt->user_regs.fs = __KERNEL_PERCPU;
310 ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
311#else
312 ctxt->gs_base_kernel = per_cpu_offset(cpu);
313#endif
314 ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
315 ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
316
317 memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
318
319 xen_copy_trap_info(ctxt->trap_ctxt);
320
321 ctxt->ldt_ents = 0;
322
323 BUG_ON((unsigned long)gdt & ~PAGE_MASK);
324
325 gdt_mfn = arbitrary_virt_to_mfn(gdt);
326 make_lowmem_page_readonly(gdt);
327 make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
328
329 ctxt->gdt_frames[0] = gdt_mfn;
330 ctxt->gdt_ents = GDT_ENTRIES;
331
332 ctxt->user_regs.cs = __KERNEL_CS;
333 ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
334
335 ctxt->kernel_ss = __KERNEL_DS;
336 ctxt->kernel_sp = idle->thread.sp0;
337
338#ifdef CONFIG_X86_32
339 ctxt->event_callback_cs = __KERNEL_CS;
340 ctxt->failsafe_callback_cs = __KERNEL_CS;
341#endif
342 ctxt->event_callback_eip = (unsigned long)xen_hypervisor_callback;
343 ctxt->failsafe_callback_eip = (unsigned long)xen_failsafe_callback;
344
345 per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
346 ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
347
348 if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
349 BUG();
350
351 kfree(ctxt);
352 return 0;
353}
354
355static int __cpuinit xen_cpu_up(unsigned int cpu, struct task_struct *idle)
356{
357 int rc;
358
359 per_cpu(current_task, cpu) = idle;
360#ifdef CONFIG_X86_32
361 irq_ctx_init(cpu);
362#else
363 clear_tsk_thread_flag(idle, TIF_FORK);
364 per_cpu(kernel_stack, cpu) =
365 (unsigned long)task_stack_page(idle) -
366 KERNEL_STACK_OFFSET + THREAD_SIZE;
367#endif
368 xen_setup_runstate_info(cpu);
369 xen_setup_timer(cpu);
370 xen_init_lock_cpu(cpu);
371
372 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
373
374 /* make sure interrupts start blocked */
375 per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
376
377 rc = cpu_initialize_context(cpu, idle);
378 if (rc)
379 return rc;
380
381 if (num_online_cpus() == 1)
382 alternatives_smp_switch(1);
383
384 rc = xen_smp_intr_init(cpu);
385 if (rc)
386 return rc;
387
388 rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
389 BUG_ON(rc);
390
391 while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
392 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
393 barrier();
394 }
395
396 return 0;
397}
398
399static void xen_smp_cpus_done(unsigned int max_cpus)
400{
401}
402
403#ifdef CONFIG_HOTPLUG_CPU
404static int xen_cpu_disable(void)
405{
406 unsigned int cpu = smp_processor_id();
407 if (cpu == 0)
408 return -EBUSY;
409
410 cpu_disable_common();
411
412 load_cr3(swapper_pg_dir);
413 return 0;
414}
415
416static void xen_cpu_die(unsigned int cpu)
417{
418 while (HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
419 current->state = TASK_UNINTERRUPTIBLE;
420 schedule_timeout(HZ/10);
421 }
422 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
423 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
424 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
425 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), NULL);
426 unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL);
427 xen_uninit_lock_cpu(cpu);
428 xen_teardown_timer(cpu);
429
430 if (num_online_cpus() == 1)
431 alternatives_smp_switch(0);
432}
433
434static void __cpuinit xen_play_dead(void) /* used only with HOTPLUG_CPU */
435{
436 play_dead_common();
437 HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
438 cpu_bringup();
439 /*
440 * Balance out the preempt calls - as we are running in cpu_idle
441 * loop which has been called at bootup from cpu_bringup_and_idle.
442 * The cpucpu_bringup_and_idle called cpu_bringup which made a
443 * preempt_disable() So this preempt_enable will balance it out.
444 */
445 preempt_enable();
446}
447
448#else /* !CONFIG_HOTPLUG_CPU */
449static int xen_cpu_disable(void)
450{
451 return -ENOSYS;
452}
453
454static void xen_cpu_die(unsigned int cpu)
455{
456 BUG();
457}
458
459static void xen_play_dead(void)
460{
461 BUG();
462}
463
464#endif
465static void stop_self(void *v)
466{
467 int cpu = smp_processor_id();
468
469 /* make sure we're not pinning something down */
470 load_cr3(swapper_pg_dir);
471 /* should set up a minimal gdt */
472
473 set_cpu_online(cpu, false);
474
475 HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
476 BUG();
477}
478
479static void xen_stop_other_cpus(int wait)
480{
481 smp_call_function(stop_self, NULL, wait);
482}
483
484static void xen_smp_send_reschedule(int cpu)
485{
486 xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
487}
488
489static void __xen_send_IPI_mask(const struct cpumask *mask,
490 int vector)
491{
492 unsigned cpu;
493
494 for_each_cpu_and(cpu, mask, cpu_online_mask)
495 xen_send_IPI_one(cpu, vector);
496}
497
498static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
499{
500 int cpu;
501
502 __xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
503
504 /* Make sure other vcpus get a chance to run if they need to. */
505 for_each_cpu(cpu, mask) {
506 if (xen_vcpu_stolen(cpu)) {
507 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
508 break;
509 }
510 }
511}
512
513static void xen_smp_send_call_function_single_ipi(int cpu)
514{
515 __xen_send_IPI_mask(cpumask_of(cpu),
516 XEN_CALL_FUNCTION_SINGLE_VECTOR);
517}
518
519static inline int xen_map_vector(int vector)
520{
521 int xen_vector;
522
523 switch (vector) {
524 case RESCHEDULE_VECTOR:
525 xen_vector = XEN_RESCHEDULE_VECTOR;
526 break;
527 case CALL_FUNCTION_VECTOR:
528 xen_vector = XEN_CALL_FUNCTION_VECTOR;
529 break;
530 case CALL_FUNCTION_SINGLE_VECTOR:
531 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
532 break;
533 case IRQ_WORK_VECTOR:
534 xen_vector = XEN_IRQ_WORK_VECTOR;
535 break;
536 default:
537 xen_vector = -1;
538 printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
539 vector);
540 }
541
542 return xen_vector;
543}
544
545void xen_send_IPI_mask(const struct cpumask *mask,
546 int vector)
547{
548 int xen_vector = xen_map_vector(vector);
549
550 if (xen_vector >= 0)
551 __xen_send_IPI_mask(mask, xen_vector);
552}
553
554void xen_send_IPI_all(int vector)
555{
556 int xen_vector = xen_map_vector(vector);
557
558 if (xen_vector >= 0)
559 __xen_send_IPI_mask(cpu_online_mask, xen_vector);
560}
561
562void xen_send_IPI_self(int vector)
563{
564 int xen_vector = xen_map_vector(vector);
565
566 if (xen_vector >= 0)
567 xen_send_IPI_one(smp_processor_id(), xen_vector);
568}
569
570void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
571 int vector)
572{
573 unsigned cpu;
574 unsigned int this_cpu = smp_processor_id();
575
576 if (!(num_online_cpus() > 1))
577 return;
578
579 for_each_cpu_and(cpu, mask, cpu_online_mask) {
580 if (this_cpu == cpu)
581 continue;
582
583 xen_smp_send_call_function_single_ipi(cpu);
584 }
585}
586
587void xen_send_IPI_allbutself(int vector)
588{
589 int xen_vector = xen_map_vector(vector);
590
591 if (xen_vector >= 0)
592 xen_send_IPI_mask_allbutself(cpu_online_mask, xen_vector);
593}
594
595static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
596{
597 irq_enter();
598 generic_smp_call_function_interrupt();
599 inc_irq_stat(irq_call_count);
600 irq_exit();
601
602 return IRQ_HANDLED;
603}
604
605static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
606{
607 irq_enter();
608 generic_smp_call_function_single_interrupt();
609 inc_irq_stat(irq_call_count);
610 irq_exit();
611
612 return IRQ_HANDLED;
613}
614
615static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id)
616{
617 irq_enter();
618 irq_work_run();
619 inc_irq_stat(apic_irq_work_irqs);
620 irq_exit();
621
622 return IRQ_HANDLED;
623}
624
625static const struct smp_ops xen_smp_ops __initconst = {
626 .smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
627 .smp_prepare_cpus = xen_smp_prepare_cpus,
628 .smp_cpus_done = xen_smp_cpus_done,
629
630 .cpu_up = xen_cpu_up,
631 .cpu_die = xen_cpu_die,
632 .cpu_disable = xen_cpu_disable,
633 .play_dead = xen_play_dead,
634
635 .stop_other_cpus = xen_stop_other_cpus,
636 .smp_send_reschedule = xen_smp_send_reschedule,
637
638 .send_call_func_ipi = xen_smp_send_call_function_ipi,
639 .send_call_func_single_ipi = xen_smp_send_call_function_single_ipi,
640};
641
642void __init xen_smp_init(void)
643{
644 smp_ops = xen_smp_ops;
645 xen_fill_possible_map();
646 xen_init_spinlocks();
647}
648
649static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
650{
651 native_smp_prepare_cpus(max_cpus);
652 WARN_ON(xen_smp_intr_init(0));
653
654 xen_init_lock_cpu(0);
655}
656
657static int __cpuinit xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle)
658{
659 int rc;
660 rc = native_cpu_up(cpu, tidle);
661 WARN_ON (xen_smp_intr_init(cpu));
662 return rc;
663}
664
665static void xen_hvm_cpu_die(unsigned int cpu)
666{
667 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
668 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
669 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
670 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), NULL);
671 unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL);
672 native_cpu_die(cpu);
673}
674
675void __init xen_hvm_smp_init(void)
676{
677 if (!xen_have_vector_callback)
678 return;
679 smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
680 smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
681 smp_ops.cpu_up = xen_hvm_cpu_up;
682 smp_ops.cpu_die = xen_hvm_cpu_die;
683 smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
684 smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
685}