smp.c

  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
 13static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
 14static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
 15static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
 16static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 };
 17
 18static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
 19static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
 20
 21/*
 22 * Reschedule call back.
 23 */
 24static 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
 32void 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
 61int 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
133void __init xen_smp_cpus_done(unsigned int max_cpus)
134{
135	if (xen_hvm_domain())
136		native_smp_cpus_done(max_cpus);
137}
138
139void xen_smp_send_reschedule(int cpu)
140{
141	xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
142}
143
144static 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
153void 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
168void 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
174static 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
206void 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
215void 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
223void 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
231void 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
249void xen_send_IPI_allbutself(int vector)
250{
251	xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
252}
253
254static 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
262static 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}