tm-signal.S

  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/*
  3 * Copyright 2015, Cyril Bur, IBM Corp.
  4 */
  5
  6#include "basic_asm.h"
  7#include "gpr_asm.h"
  8#include "fpu_asm.h"
  9#include "vmx_asm.h"
 10#include "vsx_asm.h"
 11
 12/*
 13 * Large caveat here being that the caller cannot expect the
 14 * signal to always be sent! The hardware can (AND WILL!) abort
 15 * the transaction between the tbegin and the tsuspend (however
 16 * unlikely it seems or infrequently it actually happens).
 17 * You have been warned.
 18 */
 19/* long tm_signal_self(pid_t pid, long *gprs, double *fps, vector *vms, vector *vss); */
 20FUNC_START(tm_signal_self_context_load)
 21	PUSH_BASIC_STACK(512)
 22	/*
 23	 * Don't strictly need to save and restore as it depends on if
 24	 * we're going to use them, however this reduces messy logic
 25	 */
 26	PUSH_VMX(STACK_FRAME_LOCAL(5,0),r8)
 27	PUSH_FPU(512)
 28	PUSH_NVREGS_BELOW_FPU(512)
 29	std r3, STACK_FRAME_PARAM(0)(sp) /* pid */
 30	std r4, STACK_FRAME_PARAM(1)(sp) /* gps */
 31	std r5, STACK_FRAME_PARAM(2)(sp) /* fps */
 32	std r6, STACK_FRAME_PARAM(3)(sp) /* vms */
 33	std r7, STACK_FRAME_PARAM(4)(sp) /* vss */
 34
 35	ld r3, STACK_FRAME_PARAM(1)(sp)
 36	cmpdi r3, 0
 37	beq skip_gpr_lc
 38	bl load_gpr
 39skip_gpr_lc:
 40	ld r3, STACK_FRAME_PARAM(2)(sp)
 41	cmpdi	r3, 0
 42	beq	skip_fpu_lc
 43	bl load_fpu
 44skip_fpu_lc:
 45	ld r3, STACK_FRAME_PARAM(3)(sp)
 46	cmpdi r3, 0
 47	beq	skip_vmx_lc
 48	bl load_vmx
 49skip_vmx_lc:
 50	ld r3, STACK_FRAME_PARAM(4)(sp)
 51	cmpdi	r3, 0
 52	beq	skip_vsx_lc
 53	bl load_vsx
 54skip_vsx_lc:
 55	/*
 56	 * Set r3 (return value) before tbegin. Use the pid as a known
 57	 * 'all good' return value, zero is used to indicate a non-doomed
 58	 * transaction.
 59	 */
 60	ld	r3, STACK_FRAME_PARAM(0)(sp)
 61	tbegin.
 62	beq	1f
 63	tsuspend. /* Can't enter a syscall transactionally */
 64	ld	r3, STACK_FRAME_PARAM(1)(sp)
 65	cmpdi	r3, 0
 66	beq skip_gpr_lt
 67	/* Get the second half of the array */
 68	addi	r3, r3, 8 * 18
 69	bl load_gpr
 70skip_gpr_lt:
 71	ld r3, STACK_FRAME_PARAM(2)(sp)
 72	cmpdi	r3, 0
 73	beq	skip_fpu_lt
 74	/* Get the second half of the array */
 75	addi	r3, r3, 8 * 18
 76	bl load_fpu
 77skip_fpu_lt:
 78	ld r3, STACK_FRAME_PARAM(3)(sp)
 79	cmpdi r3, 0
 80	beq	skip_vmx_lt
 81	/* Get the second half of the array */
 82	addi	r3, r3, 16 * 12
 83	bl load_vmx
 84skip_vmx_lt:
 85	ld r3, STACK_FRAME_PARAM(4)(sp)
 86	cmpdi	r3, 0
 87	beq	skip_vsx_lt
 88	/* Get the second half of the array */
 89	addi	r3, r3, 16 * 12
 90	bl load_vsx
 91skip_vsx_lt:
 92	li	r0, 37 /* sys_kill */
 93	ld r3, STACK_FRAME_PARAM(0)(sp) /* pid */
 94	li r4, 10 /* SIGUSR1 */
 95	sc /* Taking the signal will doom the transaction */
 96	tabort. 0
 97	tresume. /* Be super sure we abort */
 98	/*
 99	 * This will cause us to resume doomed transaction and cause
100	 * hardware to cleanup, we'll end up at 1: anything between
101	 * tresume. and 1: shouldn't ever run.
102	 */
103	li r3, 0
104	1:
105	POP_VMX(STACK_FRAME_LOCAL(5,0),r4)
106	POP_FPU(512)
107	POP_NVREGS_BELOW_FPU(512)
108	POP_BASIC_STACK(512)
109	blr
110FUNC_END(tm_signal_self_context_load)