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-rw-r--r--arch/s390/kernel/cpufeature.c46
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 000000000..1b2ae42a0
--- /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);