xref: /linux/arch/x86/xen/smp.c (revision 50a0844bf8c4d38be540e423672ef9408d029252)
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 	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 
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 	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 
134 void __init xen_smp_cpus_done(unsigned int max_cpus)
135 {
136 	if (xen_hvm_domain())
137 		native_smp_cpus_done(max_cpus);
138 }
139 
140 void xen_smp_send_reschedule(int cpu)
141 {
142 	xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
143 }
144 
145 static 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 
154 void xen_smp_send_call_function_ipi(const struct cpumask *mask)
155 {
156 	int cpu;
157 
158 	__xen_send_IPI_mask(mask, 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(cpu)) {
163 			HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
164 			break;
165 		}
166 	}
167 }
168 
169 void xen_smp_send_call_function_single_ipi(int cpu)
170 {
171 	__xen_send_IPI_mask(cpumask_of(cpu),
172 			  XEN_CALL_FUNCTION_SINGLE_VECTOR);
173 }
174 
175 static 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 
207 void 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, xen_vector);
214 }
215 
216 void 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, xen_vector);
222 }
223 
224 void 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(), xen_vector);
230 }
231 
232 void 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, xen_vector);
247 	}
248 }
249 
250 void xen_send_IPI_allbutself(int vector)
251 {
252 	xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
253 }
254 
255 static 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 
263 static 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