/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * test helper assembly functions
 *
 * Copyright (C) 2016 Simon Guo, IBM Corporation.
 * Copyright 2022 Michael Ellerman, IBM Corporation.
 */
#include "basic_asm.h"

#define GPR_SIZE        __SIZEOF_LONG__
#define FIRST_GPR       14
#define NUM_GPRS        (32 - FIRST_GPR)
#define STACK_SIZE      (NUM_GPRS * GPR_SIZE)

// gpr_child_loop(int *read_flag, int *write_flag,
//                unsigned long *gpr_buf, double *fpr_buf);
FUNC_START(gpr_child_loop)
        // r3 = read_flag
        // r4 = write_flag
        // r5 = gpr_buf
        // r6 = fpr_buf
        PUSH_BASIC_STACK(STACK_SIZE)

        // Save non-volatile GPRs
        OP_REGS PPC_STL, GPR_SIZE, FIRST_GPR, 31, %r1, STACK_FRAME_LOCAL(0, 0), FIRST_GPR

        // Load GPRs with expected values
        OP_REGS PPC_LL, GPR_SIZE, FIRST_GPR, 31, r5, 0, FIRST_GPR

        // Load FPRs with expected values
        OP_REGS lfd, 8, 0, 31, r6

        // Signal to parent that we're ready
        li      r0, 1
        stw     r0, 0(r4)

        // Wait for parent to finish
1:      lwz     r0, 0(r3)
        cmpwi   r0, 0
        beq     1b      // Loop while flag is zero

        // Save GPRs back to caller buffer
        OP_REGS PPC_STL, GPR_SIZE, FIRST_GPR, 31, r5, 0, FIRST_GPR

        // Save FPRs
        OP_REGS stfd, 8, 0, 31, r6

        // Reload non-volatile GPRs
        OP_REGS PPC_LL, GPR_SIZE, FIRST_GPR, 31, %r1, STACK_FRAME_LOCAL(0, 0), FIRST_GPR

        POP_BASIC_STACK(STACK_SIZE)
        blr