GNU Linux-libre 4.14.266-gnu1
[releases.git] / arch / x86 / xen / smp.c
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
14 static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
15 static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
16 static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
17 static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 };
18
19 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
20 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
21
22 /*
23  * Reschedule call back.
24  */
25 static 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
33 void xen_smp_intr_free(unsigned int cpu)
34 {
35         if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
36                 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
37                 per_cpu(xen_resched_irq, cpu).irq = -1;
38                 kfree(per_cpu(xen_resched_irq, cpu).name);
39                 per_cpu(xen_resched_irq, cpu).name = NULL;
40         }
41         if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
42                 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
43                 per_cpu(xen_callfunc_irq, cpu).irq = -1;
44                 kfree(per_cpu(xen_callfunc_irq, cpu).name);
45                 per_cpu(xen_callfunc_irq, cpu).name = NULL;
46         }
47         if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
48                 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
49                 per_cpu(xen_debug_irq, cpu).irq = -1;
50                 kfree(per_cpu(xen_debug_irq, cpu).name);
51                 per_cpu(xen_debug_irq, cpu).name = NULL;
52         }
53         if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
54                 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
55                                        NULL);
56                 per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
57                 kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
58                 per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
59         }
60 }
61
62 int 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         rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
69                                     cpu,
70                                     xen_reschedule_interrupt,
71                                     IRQF_PERCPU|IRQF_NOBALANCING,
72                                     resched_name,
73                                     NULL);
74         if (rc < 0)
75                 goto fail;
76         per_cpu(xen_resched_irq, cpu).irq = rc;
77         per_cpu(xen_resched_irq, cpu).name = resched_name;
78
79         callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
80         rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
81                                     cpu,
82                                     xen_call_function_interrupt,
83                                     IRQF_PERCPU|IRQF_NOBALANCING,
84                                     callfunc_name,
85                                     NULL);
86         if (rc < 0)
87                 goto fail;
88         per_cpu(xen_callfunc_irq, cpu).irq = rc;
89         per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
90
91         debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
92         rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
93                                      IRQF_PERCPU | IRQF_NOBALANCING,
94                                      debug_name, NULL);
95         if (rc < 0)
96                 goto fail;
97         per_cpu(xen_debug_irq, cpu).irq = rc;
98         per_cpu(xen_debug_irq, cpu).name = debug_name;
99
100         callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
101         rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
102                                     cpu,
103                                     xen_call_function_single_interrupt,
104                                     IRQF_PERCPU|IRQF_NOBALANCING,
105                                     callfunc_name,
106                                     NULL);
107         if (rc < 0)
108                 goto fail;
109         per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
110         per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
111
112         return 0;
113
114  fail:
115         xen_smp_intr_free(cpu);
116         return rc;
117 }
118
119 void __init xen_smp_cpus_done(unsigned int max_cpus)
120 {
121         int cpu, rc, count = 0;
122
123         if (xen_hvm_domain())
124                 native_smp_cpus_done(max_cpus);
125
126         if (xen_have_vcpu_info_placement)
127                 return;
128
129         for_each_online_cpu(cpu) {
130                 if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
131                         continue;
132
133                 rc = cpu_down(cpu);
134
135                 if (rc == 0) {
136                         /*
137                          * Reset vcpu_info so this cpu cannot be onlined again.
138                          */
139                         xen_vcpu_info_reset(cpu);
140                         count++;
141                 } else {
142                         pr_warn("%s: failed to bring CPU %d down, error %d\n",
143                                 __func__, cpu, rc);
144                 }
145         }
146         WARN(count, "%s: brought %d CPUs offline\n", __func__, count);
147 }
148
149 void xen_smp_send_reschedule(int cpu)
150 {
151         xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
152 }
153
154 static void __xen_send_IPI_mask(const struct cpumask *mask,
155                               int vector)
156 {
157         unsigned cpu;
158
159         for_each_cpu_and(cpu, mask, cpu_online_mask)
160                 xen_send_IPI_one(cpu, vector);
161 }
162
163 void xen_smp_send_call_function_ipi(const struct cpumask *mask)
164 {
165         int cpu;
166
167         __xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
168
169         /* Make sure other vcpus get a chance to run if they need to. */
170         for_each_cpu(cpu, mask) {
171                 if (xen_vcpu_stolen(cpu)) {
172                         HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
173                         break;
174                 }
175         }
176 }
177
178 void xen_smp_send_call_function_single_ipi(int cpu)
179 {
180         __xen_send_IPI_mask(cpumask_of(cpu),
181                           XEN_CALL_FUNCTION_SINGLE_VECTOR);
182 }
183
184 static inline int xen_map_vector(int vector)
185 {
186         int xen_vector;
187
188         switch (vector) {
189         case RESCHEDULE_VECTOR:
190                 xen_vector = XEN_RESCHEDULE_VECTOR;
191                 break;
192         case CALL_FUNCTION_VECTOR:
193                 xen_vector = XEN_CALL_FUNCTION_VECTOR;
194                 break;
195         case CALL_FUNCTION_SINGLE_VECTOR:
196                 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
197                 break;
198         case IRQ_WORK_VECTOR:
199                 xen_vector = XEN_IRQ_WORK_VECTOR;
200                 break;
201 #ifdef CONFIG_X86_64
202         case NMI_VECTOR:
203         case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
204                 xen_vector = XEN_NMI_VECTOR;
205                 break;
206 #endif
207         default:
208                 xen_vector = -1;
209                 printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
210                         vector);
211         }
212
213         return xen_vector;
214 }
215
216 void xen_send_IPI_mask(const struct cpumask *mask,
217                               int vector)
218 {
219         int xen_vector = xen_map_vector(vector);
220
221         if (xen_vector >= 0)
222                 __xen_send_IPI_mask(mask, xen_vector);
223 }
224
225 void xen_send_IPI_all(int vector)
226 {
227         int xen_vector = xen_map_vector(vector);
228
229         if (xen_vector >= 0)
230                 __xen_send_IPI_mask(cpu_online_mask, xen_vector);
231 }
232
233 void xen_send_IPI_self(int vector)
234 {
235         int xen_vector = xen_map_vector(vector);
236
237         if (xen_vector >= 0)
238                 xen_send_IPI_one(smp_processor_id(), xen_vector);
239 }
240
241 void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
242                                 int vector)
243 {
244         unsigned cpu;
245         unsigned int this_cpu = smp_processor_id();
246         int xen_vector = xen_map_vector(vector);
247
248         if (!(num_online_cpus() > 1) || (xen_vector < 0))
249                 return;
250
251         for_each_cpu_and(cpu, mask, cpu_online_mask) {
252                 if (this_cpu == cpu)
253                         continue;
254
255                 xen_send_IPI_one(cpu, xen_vector);
256         }
257 }
258
259 void xen_send_IPI_allbutself(int vector)
260 {
261         xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
262 }
263
264 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
265 {
266         irq_enter();
267         generic_smp_call_function_interrupt();
268         inc_irq_stat(irq_call_count);
269         irq_exit();
270
271         return IRQ_HANDLED;
272 }
273
274 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
275 {
276         irq_enter();
277         generic_smp_call_function_single_interrupt();
278         inc_irq_stat(irq_call_count);
279         irq_exit();
280
281         return IRQ_HANDLED;
282 }