/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Processor Activity Instrumentation support for cryptography counters
 *
 *  Copyright IBM Corp. 2022
 *  Author(s): Thomas Richter <[email protected]>
 */
#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