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 */
xen_reschedule_interrupt(int irq,void * dev_id)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
xen_smp_intr_free(unsigned int cpu)33 void 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
xen_smp_intr_init(unsigned int cpu)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 per_cpu(xen_resched_irq, cpu).name = resched_name;
69 rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
70 cpu,
71 xen_reschedule_interrupt,
72 IRQF_PERCPU|IRQF_NOBALANCING,
73 resched_name,
74 NULL);
75 if (rc < 0)
76 goto fail;
77 per_cpu(xen_resched_irq, cpu).irq = rc;
78
79 callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
80 per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
81 rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
82 cpu,
83 xen_call_function_interrupt,
84 IRQF_PERCPU|IRQF_NOBALANCING,
85 callfunc_name,
86 NULL);
87 if (rc < 0)
88 goto fail;
89 per_cpu(xen_callfunc_irq, cpu).irq = rc;
90
91 if (!xen_fifo_events) {
92 debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
93 per_cpu(xen_debug_irq, cpu).name = debug_name;
94 rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu,
95 xen_debug_interrupt,
96 IRQF_PERCPU | IRQF_NOBALANCING,
97 debug_name, NULL);
98 if (rc < 0)
99 goto fail;
100 per_cpu(xen_debug_irq, cpu).irq = rc;
101 }
102
103 callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
104 per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
105 rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
106 cpu,
107 xen_call_function_single_interrupt,
108 IRQF_PERCPU|IRQF_NOBALANCING,
109 callfunc_name,
110 NULL);
111 if (rc < 0)
112 goto fail;
113 per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
114
115 return 0;
116
117 fail:
118 xen_smp_intr_free(cpu);
119 return rc;
120 }
121
xen_smp_cpus_done(unsigned int max_cpus)122 void __init xen_smp_cpus_done(unsigned int max_cpus)
123 {
124 int cpu, rc, count = 0;
125
126 if (xen_hvm_domain())
127 native_smp_cpus_done(max_cpus);
128 else
129 calculate_max_logical_packages();
130
131 if (xen_have_vcpu_info_placement)
132 return;
133
134 for_each_online_cpu(cpu) {
135 if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
136 continue;
137
138 rc = remove_cpu(cpu);
139
140 if (rc == 0) {
141 /*
142 * Reset vcpu_info so this cpu cannot be onlined again.
143 */
144 xen_vcpu_info_reset(cpu);
145 count++;
146 } else {
147 pr_warn("%s: failed to bring CPU %d down, error %d\n",
148 __func__, cpu, rc);
149 }
150 }
151 WARN(count, "%s: brought %d CPUs offline\n", __func__, count);
152 }
153
xen_smp_send_reschedule(int cpu)154 void xen_smp_send_reschedule(int cpu)
155 {
156 xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
157 }
158
__xen_send_IPI_mask(const struct cpumask * mask,int vector)159 static void __xen_send_IPI_mask(const struct cpumask *mask,
160 int vector)
161 {
162 unsigned cpu;
163
164 for_each_cpu_and(cpu, mask, cpu_online_mask)
165 xen_send_IPI_one(cpu, vector);
166 }
167
xen_smp_send_call_function_ipi(const struct cpumask * mask)168 void xen_smp_send_call_function_ipi(const struct cpumask *mask)
169 {
170 int cpu;
171
172 __xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
173
174 /* Make sure other vcpus get a chance to run if they need to. */
175 for_each_cpu(cpu, mask) {
176 if (xen_vcpu_stolen(cpu)) {
177 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
178 break;
179 }
180 }
181 }
182
xen_smp_send_call_function_single_ipi(int cpu)183 void xen_smp_send_call_function_single_ipi(int cpu)
184 {
185 __xen_send_IPI_mask(cpumask_of(cpu),
186 XEN_CALL_FUNCTION_SINGLE_VECTOR);
187 }
188
xen_map_vector(int vector)189 static inline int xen_map_vector(int vector)
190 {
191 int xen_vector;
192
193 switch (vector) {
194 case RESCHEDULE_VECTOR:
195 xen_vector = XEN_RESCHEDULE_VECTOR;
196 break;
197 case CALL_FUNCTION_VECTOR:
198 xen_vector = XEN_CALL_FUNCTION_VECTOR;
199 break;
200 case CALL_FUNCTION_SINGLE_VECTOR:
201 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
202 break;
203 case IRQ_WORK_VECTOR:
204 xen_vector = XEN_IRQ_WORK_VECTOR;
205 break;
206 #ifdef CONFIG_X86_64
207 case NMI_VECTOR:
208 case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
209 xen_vector = XEN_NMI_VECTOR;
210 break;
211 #endif
212 default:
213 xen_vector = -1;
214 printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
215 vector);
216 }
217
218 return xen_vector;
219 }
220
xen_send_IPI_mask(const struct cpumask * mask,int vector)221 void xen_send_IPI_mask(const struct cpumask *mask,
222 int vector)
223 {
224 int xen_vector = xen_map_vector(vector);
225
226 if (xen_vector >= 0)
227 __xen_send_IPI_mask(mask, xen_vector);
228 }
229
xen_send_IPI_all(int vector)230 void xen_send_IPI_all(int vector)
231 {
232 int xen_vector = xen_map_vector(vector);
233
234 if (xen_vector >= 0)
235 __xen_send_IPI_mask(cpu_online_mask, xen_vector);
236 }
237
xen_send_IPI_self(int vector)238 void xen_send_IPI_self(int vector)
239 {
240 int xen_vector = xen_map_vector(vector);
241
242 if (xen_vector >= 0)
243 xen_send_IPI_one(smp_processor_id(), xen_vector);
244 }
245
xen_send_IPI_mask_allbutself(const struct cpumask * mask,int vector)246 void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
247 int vector)
248 {
249 unsigned cpu;
250 unsigned int this_cpu = smp_processor_id();
251 int xen_vector = xen_map_vector(vector);
252
253 if (!(num_online_cpus() > 1) || (xen_vector < 0))
254 return;
255
256 for_each_cpu_and(cpu, mask, cpu_online_mask) {
257 if (this_cpu == cpu)
258 continue;
259
260 xen_send_IPI_one(cpu, xen_vector);
261 }
262 }
263
xen_send_IPI_allbutself(int vector)264 void xen_send_IPI_allbutself(int vector)
265 {
266 xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
267 }
268
xen_call_function_interrupt(int irq,void * dev_id)269 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
270 {
271 irq_enter();
272 generic_smp_call_function_interrupt();
273 inc_irq_stat(irq_call_count);
274 irq_exit();
275
276 return IRQ_HANDLED;
277 }
278
xen_call_function_single_interrupt(int irq,void * dev_id)279 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
280 {
281 irq_enter();
282 generic_smp_call_function_single_interrupt();
283 inc_irq_stat(irq_call_count);
284 irq_exit();
285
286 return IRQ_HANDLED;
287 }
288