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, "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
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, 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, 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
169void 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
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, 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, 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(), 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, 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