xref: /linux/arch/x86/xen/smp.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
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 
13 static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
14 static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
15 static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
16 static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 };
17 
18 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
19 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
20 
21 /*
22  * Reschedule call back.
23  */
24 static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
25 {
26 	inc_irq_stat(irq_resched_count);
27 	scheduler_ipi();
28 
29 	return IRQ_HANDLED;
30 }
31 
32 void xen_smp_intr_free(unsigned int cpu)
33 {
34 	kfree(per_cpu(xen_resched_irq, cpu).name);
35 	per_cpu(xen_resched_irq, cpu).name = NULL;
36 	if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
37 		unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
38 		per_cpu(xen_resched_irq, cpu).irq = -1;
39 	}
40 	kfree(per_cpu(xen_callfunc_irq, cpu).name);
41 	per_cpu(xen_callfunc_irq, cpu).name = NULL;
42 	if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
43 		unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
44 		per_cpu(xen_callfunc_irq, cpu).irq = -1;
45 	}
46 	kfree(per_cpu(xen_debug_irq, cpu).name);
47 	per_cpu(xen_debug_irq, cpu).name = NULL;
48 	if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
49 		unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
50 		per_cpu(xen_debug_irq, cpu).irq = -1;
51 	}
52 	kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
53 	per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
54 	if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
55 		unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
56 				       NULL);
57 		per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
58 	}
59 }
60 
61 int xen_smp_intr_init(unsigned int cpu)
62 {
63 	int rc;
64 	char *resched_name, *callfunc_name, *debug_name;
65 
66 	resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
67 	if (!resched_name)
68 		goto fail_mem;
69 	per_cpu(xen_resched_irq, cpu).name = resched_name;
70 	rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
71 				    cpu,
72 				    xen_reschedule_interrupt,
73 				    IRQF_PERCPU|IRQF_NOBALANCING,
74 				    resched_name,
75 				    NULL);
76 	if (rc < 0)
77 		goto fail;
78 	per_cpu(xen_resched_irq, cpu).irq = rc;
79 
80 	callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
81 	if (!callfunc_name)
82 		goto fail_mem;
83 	per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
84 	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
85 				    cpu,
86 				    xen_call_function_interrupt,
87 				    IRQF_PERCPU|IRQF_NOBALANCING,
88 				    callfunc_name,
89 				    NULL);
90 	if (rc < 0)
91 		goto fail;
92 	per_cpu(xen_callfunc_irq, cpu).irq = rc;
93 
94 	if (!xen_fifo_events) {
95 		debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
96 		if (!debug_name)
97 			goto fail_mem;
98 
99 		per_cpu(xen_debug_irq, cpu).name = debug_name;
100 		rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu,
101 					     xen_debug_interrupt,
102 					     IRQF_PERCPU | IRQF_NOBALANCING,
103 					     debug_name, NULL);
104 		if (rc < 0)
105 			goto fail;
106 		per_cpu(xen_debug_irq, cpu).irq = rc;
107 	}
108 
109 	callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
110 	if (!callfunc_name)
111 		goto fail_mem;
112 
113 	per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
114 	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
115 				    cpu,
116 				    xen_call_function_single_interrupt,
117 				    IRQF_PERCPU|IRQF_NOBALANCING,
118 				    callfunc_name,
119 				    NULL);
120 	if (rc < 0)
121 		goto fail;
122 	per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
123 
124 	return 0;
125 
126  fail_mem:
127 	rc = -ENOMEM;
128  fail:
129 	xen_smp_intr_free(cpu);
130 	return rc;
131 }
132 
133 void __init xen_smp_cpus_done(unsigned int max_cpus)
134 {
135 	if (xen_hvm_domain())
136 		native_smp_cpus_done(max_cpus);
137 }
138 
139 void xen_smp_send_reschedule(int cpu)
140 {
141 	xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
142 }
143 
144 static void __xen_send_IPI_mask(const struct cpumask *mask,
145 			      int vector)
146 {
147 	unsigned cpu;
148 
149 	for_each_cpu_and(cpu, mask, cpu_online_mask)
150 		xen_send_IPI_one(cpu, vector);
151 }
152 
153 void xen_smp_send_call_function_ipi(const struct cpumask *mask)
154 {
155 	int cpu;
156 
157 	__xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
158 
159 	/* Make sure other vcpus get a chance to run if they need to. */
160 	for_each_cpu(cpu, mask) {
161 		if (xen_vcpu_stolen(cpu)) {
162 			HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
163 			break;
164 		}
165 	}
166 }
167 
168 void xen_smp_send_call_function_single_ipi(int cpu)
169 {
170 	__xen_send_IPI_mask(cpumask_of(cpu),
171 			  XEN_CALL_FUNCTION_SINGLE_VECTOR);
172 }
173 
174 static inline int xen_map_vector(int vector)
175 {
176 	int xen_vector;
177 
178 	switch (vector) {
179 	case RESCHEDULE_VECTOR:
180 		xen_vector = XEN_RESCHEDULE_VECTOR;
181 		break;
182 	case CALL_FUNCTION_VECTOR:
183 		xen_vector = XEN_CALL_FUNCTION_VECTOR;
184 		break;
185 	case CALL_FUNCTION_SINGLE_VECTOR:
186 		xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
187 		break;
188 	case IRQ_WORK_VECTOR:
189 		xen_vector = XEN_IRQ_WORK_VECTOR;
190 		break;
191 #ifdef CONFIG_X86_64
192 	case NMI_VECTOR:
193 	case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
194 		xen_vector = XEN_NMI_VECTOR;
195 		break;
196 #endif
197 	default:
198 		xen_vector = -1;
199 		printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
200 			vector);
201 	}
202 
203 	return xen_vector;
204 }
205 
206 void xen_send_IPI_mask(const struct cpumask *mask,
207 			      int vector)
208 {
209 	int xen_vector = xen_map_vector(vector);
210 
211 	if (xen_vector >= 0)
212 		__xen_send_IPI_mask(mask, xen_vector);
213 }
214 
215 void xen_send_IPI_all(int vector)
216 {
217 	int xen_vector = xen_map_vector(vector);
218 
219 	if (xen_vector >= 0)
220 		__xen_send_IPI_mask(cpu_online_mask, xen_vector);
221 }
222 
223 void xen_send_IPI_self(int vector)
224 {
225 	int xen_vector = xen_map_vector(vector);
226 
227 	if (xen_vector >= 0)
228 		xen_send_IPI_one(smp_processor_id(), xen_vector);
229 }
230 
231 void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
232 				int vector)
233 {
234 	unsigned cpu;
235 	unsigned int this_cpu = smp_processor_id();
236 	int xen_vector = xen_map_vector(vector);
237 
238 	if (!(num_online_cpus() > 1) || (xen_vector < 0))
239 		return;
240 
241 	for_each_cpu_and(cpu, mask, cpu_online_mask) {
242 		if (this_cpu == cpu)
243 			continue;
244 
245 		xen_send_IPI_one(cpu, xen_vector);
246 	}
247 }
248 
249 void xen_send_IPI_allbutself(int vector)
250 {
251 	xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
252 }
253 
254 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
255 {
256 	generic_smp_call_function_interrupt();
257 	inc_irq_stat(irq_call_count);
258 
259 	return IRQ_HANDLED;
260 }
261 
262 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
263 {
264 	generic_smp_call_function_single_interrupt();
265 	inc_irq_stat(irq_call_count);
266 
267 	return IRQ_HANDLED;
268 }
269