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// SPDX-License-Identifier: GPL-2.0
/*
* Testsuite for NMI: IPIs
*
* Started by Don Zickus:
* (using lib/locking-selftest.c as a guide)
*
* Copyright (C) 2011 Red Hat, Inc., Don Zickus <dzickus@redhat.com>
*/
#include <linux/smp.h>
#include <linux/cpumask.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/percpu.h>
#include <asm/apic.h>
#include <asm/nmi.h>
#define SUCCESS 0
#define FAILURE 1
#define TIMEOUT 2
static int __initdata nmi_fail;
/* check to see if NMI IPIs work on this machine */
static DECLARE_BITMAP(nmi_ipi_mask, NR_CPUS) __initdata;
static int __initdata testcase_total;
static int __initdata testcase_successes;
static int __initdata unexpected_testcase_failures;
static int __initdata unexpected_testcase_unknowns;
static int __init nmi_unk_cb(unsigned int val, struct pt_regs *regs)
{
unexpected_testcase_unknowns++;
return NMI_HANDLED;
}
static void __init init_nmi_testsuite(void)
{
/* trap all the unknown NMIs we may generate */
register_nmi_handler(NMI_UNKNOWN, nmi_unk_cb, 0, "nmi_selftest_unk",
__initdata);
}
static void __init cleanup_nmi_testsuite(void)
{
unregister_nmi_handler(NMI_UNKNOWN, "nmi_selftest_unk");
}
static int __init test_nmi_ipi_callback(unsigned int val, struct pt_regs *regs)
{
int cpu = raw_smp_processor_id();
if (cpumask_test_and_clear_cpu(cpu, to_cpumask(nmi_ipi_mask)))
return NMI_HANDLED;
return NMI_DONE;
}
static void __init test_nmi_ipi(struct cpumask *mask)
{
unsigned long timeout;
if (register_nmi_handler(NMI_LOCAL, test_nmi_ipi_callback,
NMI_FLAG_FIRST, "nmi_selftest", __initdata)) {
nmi_fail = FAILURE;
return;
}
/* sync above data before sending NMI */
wmb();
__apic_send_IPI_mask(mask, NMI_VECTOR);
/* Don't wait longer than a second */
timeout = USEC_PER_SEC;
while (!cpumask_empty(mask) && --timeout)
udelay(1);
/* What happens if we timeout, do we still unregister?? */
unregister_nmi_handler(NMI_LOCAL, "nmi_selftest");
if (!timeout)
nmi_fail = TIMEOUT;
return;
}
static void __init remote_ipi(void)
{
cpumask_copy(to_cpumask(nmi_ipi_mask), cpu_online_mask);
cpumask_clear_cpu(smp_processor_id(), to_cpumask(nmi_ipi_mask));
if (!cpumask_empty(to_cpumask(nmi_ipi_mask)))
test_nmi_ipi(to_cpumask(nmi_ipi_mask));
}
static void __init local_ipi(void)
{
cpumask_clear(to_cpumask(nmi_ipi_mask));
cpumask_set_cpu(smp_processor_id(), to_cpumask(nmi_ipi_mask));
test_nmi_ipi(to_cpumask(nmi_ipi_mask));
}
static void __init reset_nmi(void)
{
nmi_fail = 0;
}
static void __init dotest(void (*testcase_fn)(void), int expected)
{
testcase_fn();
/*
* Filter out expected failures:
*/
if (nmi_fail != expected) {
unexpected_testcase_failures++;
if (nmi_fail == FAILURE)
pr_cont("FAILED |");
else if (nmi_fail == TIMEOUT)
pr_cont("TIMEOUT|");
else
pr_cont("ERROR |");
dump_stack();
} else {
testcase_successes++;
pr_cont(" ok |");
}
pr_cont("\n");
testcase_total++;
reset_nmi();
}
void __init nmi_selftest(void)
{
init_nmi_testsuite();
/*
* Run the testsuite:
*/
pr_info("----------------\n");
pr_info("| NMI testsuite:\n");
pr_info("--------------------\n");
pr_info("%12s:", "remote IPI");
dotest(remote_ipi, SUCCESS);
pr_info("%12s:", "local IPI");
dotest(local_ipi, SUCCESS);
cleanup_nmi_testsuite();
pr_info("--------------------\n");
if (unexpected_testcase_failures) {
pr_info("BUG: %3d unexpected failures (out of %3d) - debugging disabled! |\n",
unexpected_testcase_failures, testcase_total);
} else {
pr_info("Good, all %3d testcases passed! |\n",
testcase_successes);
}
pr_info("-----------------------------------------------------------------\n");
}
|
