arch/s390/include/asm/pai.h

/* 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 : 9;
		u64 num_nnpa : 7;	/* # of supported NNPA counters */
		u64 : 32;
	};
};

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
#define PAI_NNPA_BASE			0x1800	/* First event number */
#define PAI_NNPA_MAXCTR			128	/* Max # of event counters */

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);
}

enum paievt_mode {
	PAI_MODE_NONE,
	PAI_MODE_SAMPLING,
	PAI_MODE_COUNTING,
};

#endif