LXR linux/arch/riscv/kernel/cpu

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2020 Western Digital Corporation or its affiliates.
   4 */
   5
   6#include <linux/errno.h>
   7#include <linux/mm.h>
   8#include <linux/of.h>
   9#include <linux/string.h>
  10#include <linux/sched.h>
  11#include <linux/sched/task_stack.h>
  12#include <asm/cpu_ops.h>
  13#include <asm/sbi.h>
  14#include <asm/smp.h>
  15
  16const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
  17
  18void *__cpu_up_stack_pointer[NR_CPUS] __section(".data");
  19void *__cpu_up_task_pointer[NR_CPUS] __section(".data");
  20
  21extern const struct cpu_operations cpu_ops_sbi;
  22extern const struct cpu_operations cpu_ops_spinwait;
  23
  24void cpu_update_secondary_bootdata(unsigned int cpuid,
  25                                   struct task_struct *tidle)
  26{
  27        int hartid = cpuid_to_hartid_map(cpuid);
  28
  29        /* Make sure tidle is updated */
  30        smp_mb();
  31        WRITE_ONCE(__cpu_up_stack_pointer[hartid],
  32                   task_stack_page(tidle) + THREAD_SIZE);
  33        WRITE_ONCE(__cpu_up_task_pointer[hartid], tidle);
  34}
  35
  36void __init cpu_set_ops(int cpuid)
  37{
  38#if IS_ENABLED(CONFIG_RISCV_SBI)
  39        if (sbi_probe_extension(SBI_EXT_HSM) > 0) {
  40                if (!cpuid)
  41                        pr_info("SBI v0.2 HSM extension detected\n");
  42                cpu_ops[cpuid] = &cpu_ops_sbi;
  43        } else
  44#endif
  45                cpu_ops[cpuid] = &cpu_ops_spinwait;
  46}
  47