Merge branch 'main' into zstd-linus

1 files changed, 46 insertions, 0 deletions

diff --git a/arch/s390/kernel/cpufeature.c b/arch/s390/kernel/cpufeature.c
new file mode 100644
index 000000000000..1b2ae42a0c15
--- /dev/null
+++ b/arch/s390/kernel/cpufeature.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2022
+ */
+
+#include <linux/cpufeature.h>
+#include <linux/bug.h>
+#include <asm/elf.h>
+
+enum {
+	TYPE_HWCAP,
+	TYPE_FACILITY,
+};
+
+struct s390_cpu_feature {
+	unsigned int type	: 4;
+	unsigned int num	: 28;
+};
+
+static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = {
+	[S390_CPU_FEATURE_MSA]	= {.type = TYPE_HWCAP, .num = HWCAP_NR_MSA},
+	[S390_CPU_FEATURE_VXRS]	= {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS},
+	[S390_CPU_FEATURE_UV]	= {.type = TYPE_FACILITY, .num = 158},
+};
+
+/*
+ * cpu_have_feature - Test CPU features on module initialization
+ */
+int cpu_have_feature(unsigned int num)
+{
+	struct s390_cpu_feature *feature;
+
+	if (WARN_ON_ONCE(num >= MAX_CPU_FEATURES))
+		return 0;
+	feature = &s390_cpu_features[num];
+	switch (feature->type) {
+	case TYPE_HWCAP:
+		return !!(elf_hwcap & BIT(feature->num));
+	case TYPE_FACILITY:
+		return test_facility(feature->num);
+	default:
+		WARN_ON_ONCE(1);
+		return 0;
+	}
+}
+EXPORT_SYMBOL(cpu_have_feature);