1 files changed, 74 insertions, 0 deletions
diff --git a/arch/s390/include/asm/pai.h b/arch/s390/include/asm/pai.h
new file mode 100644
index 000000000000..5b7e33ac6f0b
--- /dev/null
+++ b/arch/s390/include/asm/pai.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Processor Activity Instrumentation support for cryptography counters
+ *
+ *  Copyright IBM Corp. 2022
+ *  Author(s): Thomas Richter <tmricht@linux.ibm.com>
+ */
+#ifndef _ASM_S390_PAI_H
+#define _ASM_S390_PAI_H
+
+#include <linux/jump_label.h>
+#include <asm/lowcore.h>
+#include <asm/ptrace.h>
+
+struct qpaci_info_block {
+	u64 header;
+	struct {
+		u64 : 8;
+		u64 num_cc : 8;	/* # of supported crypto counters */
+		u64 : 48;
+	};
+};
+
+static inline int qpaci(struct qpaci_info_block *info)
+{
+	/* Size of info (in double words minus one) */
+	size_t size = sizeof(*info) / sizeof(u64) - 1;
+	int cc;
+
+	asm volatile(
+		"	lgr	0,%[size]\n"
+		"	.insn	s,0xb28f0000,%[info]\n"
+		"	lgr	%[size],0\n"
+		"	ipm	%[cc]\n"
+		"	srl	%[cc],28\n"
+		: [cc] "=d" (cc), [info] "=Q" (*info), [size] "+&d" (size)
+		:
+		: "0", "cc", "memory");
+	return cc ? (size + 1) * sizeof(u64) : 0;
+}
+
+#define PAI_CRYPTO_BASE			0x1000	/* First event number */
+#define PAI_CRYPTO_MAXCTR		256	/* Max # of event counters */
+#define PAI_CRYPTO_KERNEL_OFFSET	2048
+
+DECLARE_STATIC_KEY_FALSE(pai_key);
+
+static __always_inline void pai_kernel_enter(struct pt_regs *regs)
+{
+	if (!IS_ENABLED(CONFIG_PERF_EVENTS))
+		return;
+	if (!static_branch_unlikely(&pai_key))
+		return;
+	if (!S390_lowcore.ccd)
+		return;
+	if (!user_mode(regs))
+		return;
+	WRITE_ONCE(S390_lowcore.ccd, S390_lowcore.ccd | PAI_CRYPTO_KERNEL_OFFSET);
+}
+
+static __always_inline void pai_kernel_exit(struct pt_regs *regs)
+{
+	if (!IS_ENABLED(CONFIG_PERF_EVENTS))
+		return;
+	if (!static_branch_unlikely(&pai_key))
+		return;
+	if (!S390_lowcore.ccd)
+		return;
+	if (!user_mode(regs))
+		return;
+	WRITE_ONCE(S390_lowcore.ccd, S390_lowcore.ccd & ~PAI_CRYPTO_KERNEL_OFFSET);
+}
+
+#endif