mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
f1e58583b9
This patch enable support for cpu hotplug in RISC-V. It uses SBI HSM extension to online/offline any hart. As a result, the harts are returned to firmware once they are offline. If the harts are brought online afterwards, they re-enter Linux kernel as if a secondary hart booted for the first time. All booting requirements are honored during this process. Tested both on QEMU and HighFive Unleashed board with. Test result follows. --------------------------------------------------- Offline cpu 2 --------------------------------------------------- $ echo 0 > /sys/devices/system/cpu/cpu2/online [ 32.828684] CPU2: off $ cat /proc/cpuinfo processor : 0 hart : 0 isa : rv64imafdcsu mmu : sv48 processor : 1 hart : 1 isa : rv64imafdcsu mmu : sv48 processor : 3 hart : 3 isa : rv64imafdcsu mmu : sv48 processor : 4 hart : 4 isa : rv64imafdcsu mmu : sv48 processor : 5 hart : 5 isa : rv64imafdcsu mmu : sv48 processor : 6 hart : 6 isa : rv64imafdcsu mmu : sv48 processor : 7 hart : 7 isa : rv64imafdcsu mmu : sv48 --------------------------------------------------- online cpu 2 --------------------------------------------------- $ echo 1 > /sys/devices/system/cpu/cpu2/online $ cat /proc/cpuinfo processor : 0 hart : 0 isa : rv64imafdcsu mmu : sv48 processor : 1 hart : 1 isa : rv64imafdcsu mmu : sv48 processor : 2 hart : 2 isa : rv64imafdcsu mmu : sv48 processor : 3 hart : 3 isa : rv64imafdcsu mmu : sv48 processor : 4 hart : 4 isa : rv64imafdcsu mmu : sv48 processor : 5 hart : 5 isa : rv64imafdcsu mmu : sv48 processor : 6 hart : 6 isa : rv64imafdcsu mmu : sv48 processor : 7 hart : 7 isa : rv64imafdcsu mmu : sv48 Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org>
114 lines
2.4 KiB
C
114 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
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* Chen Liqin <liqin.chen@sunplusct.com>
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* Lennox Wu <lennox.wu@sunplusct.com>
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* Copyright (C) 2012 Regents of the University of California
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*/
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/memblock.h>
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#include <linux/sched.h>
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#include <linux/console.h>
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#include <linux/screen_info.h>
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#include <linux/of_fdt.h>
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#include <linux/of_platform.h>
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#include <linux/sched/task.h>
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#include <linux/swiotlb.h>
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#include <linux/smp.h>
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#include <asm/clint.h>
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#include <asm/cpu_ops.h>
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#include <asm/setup.h>
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#include <asm/sections.h>
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#include <asm/pgtable.h>
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#include <asm/sbi.h>
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#include <asm/tlbflush.h>
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#include <asm/thread_info.h>
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#include <asm/kasan.h>
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#include "head.h"
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#ifdef CONFIG_DUMMY_CONSOLE
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struct screen_info screen_info = {
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.orig_video_lines = 30,
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.orig_video_cols = 80,
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.orig_video_mode = 0,
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.orig_video_ega_bx = 0,
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.orig_video_isVGA = 1,
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.orig_video_points = 8
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};
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#endif
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/*
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* The lucky hart to first increment this variable will boot the other cores.
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* This is used before the kernel initializes the BSS so it can't be in the
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* BSS.
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*/
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atomic_t hart_lottery __section(.sdata);
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unsigned long boot_cpu_hartid;
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static DEFINE_PER_CPU(struct cpu, cpu_devices);
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void __init parse_dtb(void)
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{
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if (early_init_dt_scan(dtb_early_va))
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return;
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pr_err("No DTB passed to the kernel\n");
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#ifdef CONFIG_CMDLINE_FORCE
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strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
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pr_info("Forcing kernel command line to: %s\n", boot_command_line);
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#endif
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}
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void __init setup_arch(char **cmdline_p)
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{
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init_mm.start_code = (unsigned long) _stext;
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init_mm.end_code = (unsigned long) _etext;
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init_mm.end_data = (unsigned long) _edata;
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init_mm.brk = (unsigned long) _end;
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*cmdline_p = boot_command_line;
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parse_early_param();
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setup_bootmem();
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paging_init();
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unflatten_device_tree();
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clint_init_boot_cpu();
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#ifdef CONFIG_SWIOTLB
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swiotlb_init(1);
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#endif
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#ifdef CONFIG_KASAN
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kasan_init();
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#endif
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#if IS_ENABLED(CONFIG_RISCV_SBI)
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sbi_init();
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#endif
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#ifdef CONFIG_SMP
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setup_smp();
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#endif
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riscv_fill_hwcap();
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}
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static int __init topology_init(void)
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{
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int i;
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for_each_possible_cpu(i) {
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struct cpu *cpu = &per_cpu(cpu_devices, i);
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cpu->hotpluggable = cpu_has_hotplug(i);
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register_cpu(cpu, i);
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}
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return 0;
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}
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subsys_initcall(topology_init);
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