riscv: add support smp_pause / smp_resume
See https://doc.coreboot.org/arch/riscv/ we know that we need to execute smp_pause at the start of each stage and smp_resume at the end of each stage. Change-Id: I6f8159637bfb15f54f0abeb335de2ba6e9cf82fb Signed-off-by: Xiang Wang <wxjstz@126.com> Reviewed-on: https://review.coreboot.org/29023 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Reviewed-by: Philipp Hug <philipp@hug.cx>
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committed by
Patrick Georgi
parent
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85
src/arch/riscv/smp.c
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85
src/arch/riscv/smp.c
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/*
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* This file is part of the coreboot project.
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*
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* Copyright (C) 2018 HardenedLinux.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <stddef.h>
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#include <arch/encoding.h>
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#include <arch/smp/smp.h>
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#include <arch/smp/spinlock.h>
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#include <mcall.h>
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#include <commonlib/compiler.h>
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#include <console/console.h>
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void smp_pause(int working_hartid)
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{
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#define SYNCA (OTHER_HLS(working_hartid)->entry.sync_a)
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#define SYNCB (OTHER_HLS(working_hartid)->entry.sync_b)
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int hartid = read_csr(mhartid);
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if (hartid != working_hartid) {
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/* waiting for work hart */
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do {
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barrier();
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} while (SYNCA != 0x01234567);
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clear_csr(mstatus, MSTATUS_MIE);
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write_csr(mie, MIP_MSIP);
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/* count how many cores enter the halt */
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__sync_fetch_and_add(&SYNCB, 1);
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do {
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barrier();
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__asm__ volatile ("wfi");
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} while ((read_csr(mip) & MIP_MSIP) == 0);
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set_msip(hartid, 0);
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HLS()->entry.fn(HLS()->entry.arg);
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} else {
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/* Initialize the counter and
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* mark the work hart into smp_pause */
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SYNCB = 0;
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SYNCA = 0x01234567;
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/* waiting for other Hart to enter the halt */
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do {
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barrier();
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} while (SYNCB + 1 < CONFIG_RISCV_HART_NUM);
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/* initialize for the next call */
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SYNCA = 0;
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SYNCB = 0;
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}
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#undef SYNCA
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#undef SYNCB
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}
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void smp_resume(void (*fn)(void *), void *arg)
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{
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int hartid = read_csr(mhartid);
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if (fn == NULL)
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die("must pass a non-null function pointer\n");
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for (int i = 0; i < CONFIG_RISCV_HART_NUM; i++) {
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OTHER_HLS(i)->entry.fn = fn;
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OTHER_HLS(i)->entry.arg = arg;
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}
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for (int i = 0; i < CONFIG_RISCV_HART_NUM; i++)
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if (i != hartid)
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set_msip(i, 1);
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HLS()->entry.fn(HLS()->entry.arg);
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}
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