xref: /linux/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.S (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * test helper assembly functions
4 *
5 * Copyright (C) 2016 Simon Guo, IBM Corporation.
6 * Copyright 2022 Michael Ellerman, IBM Corporation.
7 */
8#include "basic_asm.h"
9
10#define GPR_SIZE	__SIZEOF_LONG__
11#define FIRST_GPR	14
12#define NUM_GPRS	(32 - FIRST_GPR)
13#define STACK_SIZE	(NUM_GPRS * GPR_SIZE)
14
15// gpr_child_loop(int *read_flag, int *write_flag,
16//		  unsigned long *gpr_buf, double *fpr_buf);
17FUNC_START(gpr_child_loop)
18	// r3 = read_flag
19	// r4 = write_flag
20	// r5 = gpr_buf
21	// r6 = fpr_buf
22	PUSH_BASIC_STACK(STACK_SIZE)
23
24	// Save non-volatile GPRs
25	OP_REGS PPC_STL, GPR_SIZE, FIRST_GPR, 31, %r1, STACK_FRAME_LOCAL(0, 0), FIRST_GPR
26
27	// Load GPRs with expected values
28	OP_REGS PPC_LL, GPR_SIZE, FIRST_GPR, 31, r5, 0, FIRST_GPR
29
30	// Load FPRs with expected values
31	OP_REGS lfd, 8, 0, 31, r6
32
33	// Signal to parent that we're ready
34	li	r0, 1
35	stw	r0, 0(r4)
36
37	// Wait for parent to finish
381:	lwz	r0, 0(r3)
39	cmpwi	r0, 0
40	beq	1b	// Loop while flag is zero
41
42	// Save GPRs back to caller buffer
43	OP_REGS PPC_STL, GPR_SIZE, FIRST_GPR, 31, r5, 0, FIRST_GPR
44
45	// Save FPRs
46	OP_REGS stfd, 8, 0, 31, r6
47
48	// Reload non-volatile GPRs
49	OP_REGS PPC_LL, GPR_SIZE, FIRST_GPR, 31, %r1, STACK_FRAME_LOCAL(0, 0), FIRST_GPR
50
51	POP_BASIC_STACK(STACK_SIZE)
52	blr
53