/*- * Copyright (c) 2024 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Nick Hudson * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include <machine/asm.h> #include "assym.h" #define UCAS_FRAME_SIZE (FB_LEN + 4 * SZREG) #define UCAS_FRAME_A0 (UCAS_FRAME_SIZE - 4 * SZREG) #define UCAS_FRAME_A1 (UCAS_FRAME_SIZE - 3 * SZREG) #define UCAS_FRAME_S0 (UCAS_FRAME_SIZE - 2 * SZREG) #define UCAS_FRAME_RA (UCAS_FRAME_SIZE - 1 * SZREG) .macro enter_ucas addi sp, sp, -UCAS_FRAME_SIZE REG_S a0, UCAS_FRAME_A0(sp) REG_S a1, UCAS_FRAME_A1(sp) REG_S s0, UCAS_FRAME_S0(sp) REG_S ra, UCAS_FRAME_RA(sp) addi s0, sp, UCAS_FRAME_SIZE .endm .macro exit_ucas REG_L s0, UCAS_FRAME_S0(sp) REG_L ra, UCAS_FRAME_RA(sp) addi sp, sp, UCAS_FRAME_SIZE .endm .macro enter_cpu_onfault // error = cpu_set_onfault(&fb, EFAULT); mv a0, sp li a1, EFAULT call cpu_set_onfault // if (error) goto fail; bnez a0, 9f .endm .macro exit_cpu_onfault // curlwp->l_md.md_onfault = NULL; REG_S zero, L_MD_ONFAULT(tp) .endm .macro set_sum // csr_sstatus_set(SR_SUM); li t1, SR_SUM csrs sstatus, t1 .endm .macro clear_sum // csr_sstatus_clear(SR_SUM); li t1, SR_SUM csrc sstatus, t1 .endm /* * int _ucas_32(volatile uint32_t *ptr, uint32_t old, * uint32_t new, uint32_t *ret) * * Implies release/acquire barriers until someone tells me * otherwise about _ucas_32/64. */ ENTRY(_ucas_32) li t0, (VM_MAXUSER_ADDRESS - 4) bltu t0, a0, 3f enter_ucas enter_cpu_onfault REG_L t0, UCAS_FRAME_A0(sp) REG_L a1, UCAS_FRAME_A1(sp) set_sum 1: lr.w a0, 0(t0) /* load old value */ bne a0, a1, 2f /* return if different */ sc.w t1, a2, 0(t0) /* store new value */ bnez t1, 1b /* succeed? nope, try again. */ 2: clear_sum sw a0, 0(a3) exit_cpu_onfault li a0, 0 // success 9: exit_ucas ret 3: li a0, EFAULT ret END(_ucas_32) #ifdef _LP64 /* * int _ucas_64(volatile uint64_t *ptr, uint64_t old, * uint64_t new, uint64_t *ret) * * Implies release/acquire barriers until someone tells me * otherwise about _ucas_32/64. */ ENTRY(_ucas_64) li t0, (VM_MAXUSER_ADDRESS - 8) bltu t0, a0, 3f enter_ucas enter_cpu_onfault REG_L t0, (FB_LEN + 0 * SZREG)(sp) REG_L a1, (FB_LEN + 1 * SZREG)(sp) set_sum 1: lr.d a0, 0(t0) /* load old value */ bne a1, a0, 2f /* return if different */ sc.d t1, a2, 0(t0) /* store new value */ bnez t1, 1b /* succeed? nope, try again. */ 2: clear_sum sd a0, 0(a3) exit_cpu_onfault li a0, 0 // success 9: exit_ucas ret 3: li a0, EFAULT ret END(_ucas_64) #endif
