swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
Tip revision: 6da6c0db5316275015e8cc2959f12a17584aeb64 authored by Linus Torvalds on 29 April 2018, 21:17:42 UTC
Linux v4.17-rc3
Linux v4.17-rc3
Tip revision: 6da6c0d
smp.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/slab.h>
#include <linux/cpumask.h>
#include <linux/percpu.h>
#include <xen/events.h>
#include <xen/hvc-console.h>
#include "xen-ops.h"
#include "smp.h"
static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 };
static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
/*
* Reschedule call back.
*/
static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
{
inc_irq_stat(irq_resched_count);
scheduler_ipi();
return IRQ_HANDLED;
}
void xen_smp_intr_free(unsigned int cpu)
{
if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
per_cpu(xen_resched_irq, cpu).irq = -1;
kfree(per_cpu(xen_resched_irq, cpu).name);
per_cpu(xen_resched_irq, cpu).name = NULL;
}
if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
per_cpu(xen_callfunc_irq, cpu).irq = -1;
kfree(per_cpu(xen_callfunc_irq, cpu).name);
per_cpu(xen_callfunc_irq, cpu).name = NULL;
}
if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
per_cpu(xen_debug_irq, cpu).irq = -1;
kfree(per_cpu(xen_debug_irq, cpu).name);
per_cpu(xen_debug_irq, cpu).name = NULL;
}
if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
NULL);
per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
}
}
int xen_smp_intr_init(unsigned int cpu)
{
int rc;
char *resched_name, *callfunc_name, *debug_name;
resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
cpu,
xen_reschedule_interrupt,
IRQF_PERCPU|IRQF_NOBALANCING,
resched_name,
NULL);
if (rc < 0)
goto fail;
per_cpu(xen_resched_irq, cpu).irq = rc;
per_cpu(xen_resched_irq, cpu).name = resched_name;
callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
cpu,
xen_call_function_interrupt,
IRQF_PERCPU|IRQF_NOBALANCING,
callfunc_name,
NULL);
if (rc < 0)
goto fail;
per_cpu(xen_callfunc_irq, cpu).irq = rc;
per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
IRQF_PERCPU | IRQF_NOBALANCING,
debug_name, NULL);
if (rc < 0)
goto fail;
per_cpu(xen_debug_irq, cpu).irq = rc;
per_cpu(xen_debug_irq, cpu).name = debug_name;
callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
cpu,
xen_call_function_single_interrupt,
IRQF_PERCPU|IRQF_NOBALANCING,
callfunc_name,
NULL);
if (rc < 0)
goto fail;
per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
return 0;
fail:
xen_smp_intr_free(cpu);
return rc;
}
void __init xen_smp_cpus_done(unsigned int max_cpus)
{
int cpu, rc, count = 0;
if (xen_hvm_domain())
native_smp_cpus_done(max_cpus);
else
calculate_max_logical_packages();
if (xen_have_vcpu_info_placement)
return;
for_each_online_cpu(cpu) {
if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
continue;
rc = cpu_down(cpu);
if (rc == 0) {
/*
* Reset vcpu_info so this cpu cannot be onlined again.
*/
xen_vcpu_info_reset(cpu);
count++;
} else {
pr_warn("%s: failed to bring CPU %d down, error %d\n",
__func__, cpu, rc);
}
}
WARN(count, "%s: brought %d CPUs offline\n", __func__, count);
}
void xen_smp_send_reschedule(int cpu)
{
xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
}
static void __xen_send_IPI_mask(const struct cpumask *mask,
int vector)
{
unsigned cpu;
for_each_cpu_and(cpu, mask, cpu_online_mask)
xen_send_IPI_one(cpu, vector);
}
void xen_smp_send_call_function_ipi(const struct cpumask *mask)
{
int cpu;
__xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
/* Make sure other vcpus get a chance to run if they need to. */
for_each_cpu(cpu, mask) {
if (xen_vcpu_stolen(cpu)) {
HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
break;
}
}
}
void xen_smp_send_call_function_single_ipi(int cpu)
{
__xen_send_IPI_mask(cpumask_of(cpu),
XEN_CALL_FUNCTION_SINGLE_VECTOR);
}
static inline int xen_map_vector(int vector)
{
int xen_vector;
switch (vector) {
case RESCHEDULE_VECTOR:
xen_vector = XEN_RESCHEDULE_VECTOR;
break;
case CALL_FUNCTION_VECTOR:
xen_vector = XEN_CALL_FUNCTION_VECTOR;
break;
case CALL_FUNCTION_SINGLE_VECTOR:
xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
break;
case IRQ_WORK_VECTOR:
xen_vector = XEN_IRQ_WORK_VECTOR;
break;
#ifdef CONFIG_X86_64
case NMI_VECTOR:
case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
xen_vector = XEN_NMI_VECTOR;
break;
#endif
default:
xen_vector = -1;
printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
vector);
}
return xen_vector;
}
void xen_send_IPI_mask(const struct cpumask *mask,
int vector)
{
int xen_vector = xen_map_vector(vector);
if (xen_vector >= 0)
__xen_send_IPI_mask(mask, xen_vector);
}
void xen_send_IPI_all(int vector)
{
int xen_vector = xen_map_vector(vector);
if (xen_vector >= 0)
__xen_send_IPI_mask(cpu_online_mask, xen_vector);
}
void xen_send_IPI_self(int vector)
{
int xen_vector = xen_map_vector(vector);
if (xen_vector >= 0)
xen_send_IPI_one(smp_processor_id(), xen_vector);
}
void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
int vector)
{
unsigned cpu;
unsigned int this_cpu = smp_processor_id();
int xen_vector = xen_map_vector(vector);
if (!(num_online_cpus() > 1) || (xen_vector < 0))
return;
for_each_cpu_and(cpu, mask, cpu_online_mask) {
if (this_cpu == cpu)
continue;
xen_send_IPI_one(cpu, xen_vector);
}
}
void xen_send_IPI_allbutself(int vector)
{
xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
}
static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
{
irq_enter();
generic_smp_call_function_interrupt();
inc_irq_stat(irq_call_count);
irq_exit();
return IRQ_HANDLED;
}
static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
{
irq_enter();
generic_smp_call_function_single_interrupt();
inc_irq_stat(irq_call_count);
irq_exit();
return IRQ_HANDLED;
}