Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 184 insertions, 0 deletions

diff --git a/arch/x86/kernel/nmi_selftest.c b/arch/x86/kernel/nmi_selftest.c
new file mode 100644
index 000000000..a1a96df3d
--- /dev/null
+++ b/arch/x86/kernel/nmi_selftest.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/x86/kernel/nmi-selftest.c
+ *
+ * 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 expected_testcase_failures;
+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)
+			printk(KERN_CONT "FAILED |");
+		else if (nmi_fail == TIMEOUT)
+			printk(KERN_CONT "TIMEOUT|");
+		else
+			printk(KERN_CONT "ERROR  |");
+		dump_stack();
+	} else {
+		testcase_successes++;
+		printk(KERN_CONT "  ok  |");
+	}
+	testcase_total++;
+
+	reset_nmi();
+}
+
+static inline void __init print_testname(const char *testname)
+{
+	printk("%12s:", testname);
+}
+
+void __init nmi_selftest(void)
+{
+	init_nmi_testsuite();
+
+        /*
+	 * Run the testsuite:
+	 */
+	printk("----------------\n");
+	printk("| NMI testsuite:\n");
+	printk("--------------------\n");
+
+	print_testname("remote IPI");
+	dotest(remote_ipi, SUCCESS);
+	printk(KERN_CONT "\n");
+	print_testname("local IPI");
+	dotest(local_ipi, SUCCESS);
+	printk(KERN_CONT "\n");
+
+	cleanup_nmi_testsuite();
+
+	if (unexpected_testcase_failures) {
+		printk("--------------------\n");
+		printk("BUG: %3d unexpected failures (out of %3d) - debugging disabled! |\n",
+			unexpected_testcase_failures, testcase_total);
+		printk("-----------------------------------------------------------------\n");
+	} else if (expected_testcase_failures && testcase_successes) {
+		printk("--------------------\n");
+		printk("%3d out of %3d testcases failed, as expected. |\n",
+			expected_testcase_failures, testcase_total);
+		printk("----------------------------------------------------\n");
+	} else if (expected_testcase_failures && !testcase_successes) {
+		printk("--------------------\n");
+		printk("All %3d testcases failed, as expected. |\n",
+			expected_testcase_failures);
+		printk("----------------------------------------\n");
+	} else {
+		printk("--------------------\n");
+		printk("Good, all %3d testcases passed! |\n",
+			testcase_successes);
+		printk("---------------------------------\n");
+	}
+}