// SPDX-License-Identifier: GPL-2.0
#include <linux/perf_event.h>
#include <linux/perf_regs.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/bug.h>
#include <asm/ptrace.h>
#include <asm/fpu.h>

u64 perf_reg_value(struct pt_regs *regs, int idx)
{
        freg_t fp;

        if (idx >= PERF_REG_S390_R0 && idx <= PERF_REG_S390_R15)
                return regs->gprs[idx];

        if (idx >= PERF_REG_S390_FP0 && idx <= PERF_REG_S390_FP15) {
                if (!user_mode(regs))
                        return 0;

                idx -= PERF_REG_S390_FP0;
                fp = *(freg_t *)(current->thread.ufpu.vxrs + idx);
                return fp.ui;
        }

        if (idx == PERF_REG_S390_MASK)
                return regs->psw.mask;
        if (idx == PERF_REG_S390_PC)
                return regs->psw.addr;

        WARN_ON_ONCE((u32)idx >= PERF_REG_S390_MAX);
        return 0;
}

#define REG_RESERVED (~((1UL << PERF_REG_S390_MAX) - 1))

int perf_reg_validate(u64 mask)
{
        if (!mask || mask & REG_RESERVED)
                return -EINVAL;

        return 0;
}

u64 perf_reg_abi(struct task_struct *task)
{
        return PERF_SAMPLE_REGS_ABI_64;
}

void perf_get_regs_user(struct perf_regs *regs_user,
                        struct pt_regs *regs)
{
        /*
         * Use the regs from the first interruption and let
         * perf_sample_regs_intr() handle interrupts (regs == get_irq_regs()).
         *
         * Also save FPU registers for user-space tasks only.
         */
        regs_user->regs = task_pt_regs(current);
        if (user_mode(regs_user->regs))
                save_user_fpu_regs();
        regs_user->abi = perf_reg_abi(current);
}