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, fmt: "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(ipi: XEN_RESCHEDULE_VECTOR,
72 cpu,
73 handler: xen_reschedule_interrupt,
74 IRQF_PERCPU|IRQF_NOBALANCING,
75 devname: 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, fmt: "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(ipi: XEN_CALL_FUNCTION_VECTOR,
86 cpu,
87 handler: xen_call_function_interrupt,
88 IRQF_PERCPU|IRQF_NOBALANCING,
89 devname: 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, fmt: "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 handler: xen_debug_interrupt,
103 IRQF_PERCPU | IRQF_NOBALANCING,
104 devname: 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, fmt: "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(ipi: XEN_CALL_FUNCTION_SINGLE_VECTOR,
116 cpu,
117 handler: xen_call_function_single_interrupt,
118 IRQF_PERCPU|IRQF_NOBALANCING,
119 devname: 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}
139
140void xen_smp_send_reschedule(int cpu)
141{
142 xen_send_IPI_one(cpu, vector: XEN_RESCHEDULE_VECTOR);
143}
144
145static void __xen_send_IPI_mask(const struct cpumask *mask,
146 int vector)
147{
148 unsigned cpu;
149
150 for_each_cpu_and(cpu, mask, cpu_online_mask)
151 xen_send_IPI_one(cpu, vector);
152}
153
154void xen_smp_send_call_function_ipi(const struct cpumask *mask)
155{
156 int cpu;
157
158 __xen_send_IPI_mask(mask, vector: XEN_CALL_FUNCTION_VECTOR);
159
160 /* Make sure other vcpus get a chance to run if they need to. */
161 for_each_cpu(cpu, mask) {
162 if (xen_vcpu_stolen(vcpu: cpu)) {
163 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
164 break;
165 }
166 }
167}
168
169void xen_smp_send_call_function_single_ipi(int cpu)
170{
171 __xen_send_IPI_mask(cpumask_of(cpu),
172 vector: XEN_CALL_FUNCTION_SINGLE_VECTOR);
173}
174
175static inline int xen_map_vector(int vector)
176{
177 int xen_vector;
178
179 switch (vector) {
180 case RESCHEDULE_VECTOR:
181 xen_vector = XEN_RESCHEDULE_VECTOR;
182 break;
183 case CALL_FUNCTION_VECTOR:
184 xen_vector = XEN_CALL_FUNCTION_VECTOR;
185 break;
186 case CALL_FUNCTION_SINGLE_VECTOR:
187 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
188 break;
189 case IRQ_WORK_VECTOR:
190 xen_vector = XEN_IRQ_WORK_VECTOR;
191 break;
192#ifdef CONFIG_X86_64
193 case NMI_VECTOR:
194 case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
195 xen_vector = XEN_NMI_VECTOR;
196 break;
197#endif
198 default:
199 xen_vector = -1;
200 printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
201 vector);
202 }
203
204 return xen_vector;
205}
206
207void xen_send_IPI_mask(const struct cpumask *mask,
208 int vector)
209{
210 int xen_vector = xen_map_vector(vector);
211
212 if (xen_vector >= 0)
213 __xen_send_IPI_mask(mask, vector: xen_vector);
214}
215
216void xen_send_IPI_all(int vector)
217{
218 int xen_vector = xen_map_vector(vector);
219
220 if (xen_vector >= 0)
221 __xen_send_IPI_mask(cpu_online_mask, vector: xen_vector);
222}
223
224void xen_send_IPI_self(int vector)
225{
226 int xen_vector = xen_map_vector(vector);
227
228 if (xen_vector >= 0)
229 xen_send_IPI_one(smp_processor_id(), vector: xen_vector);
230}
231
232void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
233 int vector)
234{
235 unsigned cpu;
236 unsigned int this_cpu = smp_processor_id();
237 int xen_vector = xen_map_vector(vector);
238
239 if (!(num_online_cpus() > 1) || (xen_vector < 0))
240 return;
241
242 for_each_cpu_and(cpu, mask, cpu_online_mask) {
243 if (this_cpu == cpu)
244 continue;
245
246 xen_send_IPI_one(cpu, vector: xen_vector);
247 }
248}
249
250void xen_send_IPI_allbutself(int vector)
251{
252 xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
253}
254
255static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
256{
257 generic_smp_call_function_interrupt();
258 inc_irq_stat(irq_call_count);
259
260 return IRQ_HANDLED;
261}
262
263static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
264{
265 generic_smp_call_function_single_interrupt();
266 inc_irq_stat(irq_call_count);
267
268 return IRQ_HANDLED;
269}
270

source code of linux/arch/x86/xen/smp.c