cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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smp.h (3955B)

      1/* SPDX-License-Identifier: GPL-2.0-only */
      2/*
      3 * Copyright (C) 2012 ARM Ltd.
      4 */
      5#ifndef __ASM_SMP_H
      6#define __ASM_SMP_H
      7
      8#include <linux/const.h>
      9
     10/* Values for secondary_data.status */
     11#define CPU_STUCK_REASON_SHIFT		(8)
     12#define CPU_BOOT_STATUS_MASK		((UL(1) << CPU_STUCK_REASON_SHIFT) - 1)
     13
     14#define CPU_MMU_OFF			(-1)
     15#define CPU_BOOT_SUCCESS		(0)
     16/* The cpu invoked ops->cpu_die, synchronise it with cpu_kill */
     17#define CPU_KILL_ME			(1)
     18/* The cpu couldn't die gracefully and is looping in the kernel */
     19#define CPU_STUCK_IN_KERNEL		(2)
     20/* Fatal system error detected by secondary CPU, crash the system */
     21#define CPU_PANIC_KERNEL		(3)
     22
     23#define CPU_STUCK_REASON_52_BIT_VA	(UL(1) << CPU_STUCK_REASON_SHIFT)
     24#define CPU_STUCK_REASON_NO_GRAN	(UL(2) << CPU_STUCK_REASON_SHIFT)
     25
     26#ifndef __ASSEMBLY__
     27
     28#include <asm/percpu.h>
     29
     30#include <linux/threads.h>
     31#include <linux/cpumask.h>
     32#include <linux/thread_info.h>
     33
     34DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);
     35
     36/*
     37 * We don't use this_cpu_read(cpu_number) as that has implicit writes to
     38 * preempt_count, and associated (compiler) barriers, that we'd like to avoid
     39 * the expense of. If we're preemptible, the value can be stale at use anyway.
     40 * And we can't use this_cpu_ptr() either, as that winds up recursing back
     41 * here under CONFIG_DEBUG_PREEMPT=y.
     42 */
     43#define raw_smp_processor_id() (*raw_cpu_ptr(&cpu_number))
     44
     45/*
     46 * Logical CPU mapping.
     47 */
     48extern u64 __cpu_logical_map[NR_CPUS];
     49extern u64 cpu_logical_map(unsigned int cpu);
     50
     51static inline void set_cpu_logical_map(unsigned int cpu, u64 hwid)
     52{
     53	__cpu_logical_map[cpu] = hwid;
     54}
     55
     56struct seq_file;
     57
     58/*
     59 * Discover the set of possible CPUs and determine their
     60 * SMP operations.
     61 */
     62extern void smp_init_cpus(void);
     63
     64/*
     65 * Register IPI interrupts with the arch SMP code
     66 */
     67extern void set_smp_ipi_range(int ipi_base, int nr_ipi);
     68
     69/*
     70 * Called from the secondary holding pen, this is the secondary CPU entry point.
     71 */
     72asmlinkage void secondary_start_kernel(void);
     73
     74/*
     75 * Initial data for bringing up a secondary CPU.
     76 * @status - Result passed back from the secondary CPU to
     77 *           indicate failure.
     78 */
     79struct secondary_data {
     80	struct task_struct *task;
     81	long status;
     82};
     83
     84extern struct secondary_data secondary_data;
     85extern long __early_cpu_boot_status;
     86extern void secondary_entry(void);
     87
     88extern void arch_send_call_function_single_ipi(int cpu);
     89extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
     90
     91#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
     92extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask);
     93#else
     94static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
     95{
     96	BUILD_BUG();
     97}
     98#endif
     99
    100extern int __cpu_disable(void);
    101
    102extern void __cpu_die(unsigned int cpu);
    103extern void cpu_die(void);
    104extern void cpu_die_early(void);
    105
    106static inline void cpu_park_loop(void)
    107{
    108	for (;;) {
    109		wfe();
    110		wfi();
    111	}
    112}
    113
    114static inline void update_cpu_boot_status(int val)
    115{
    116	WRITE_ONCE(secondary_data.status, val);
    117	/* Ensure the visibility of the status update */
    118	dsb(ishst);
    119}
    120
    121/*
    122 * The calling secondary CPU has detected serious configuration mismatch,
    123 * which calls for a kernel panic. Update the boot status and park the calling
    124 * CPU.
    125 */
    126static inline void cpu_panic_kernel(void)
    127{
    128	update_cpu_boot_status(CPU_PANIC_KERNEL);
    129	cpu_park_loop();
    130}
    131
    132/*
    133 * If a secondary CPU enters the kernel but fails to come online,
    134 * (e.g. due to mismatched features), and cannot exit the kernel,
    135 * we increment cpus_stuck_in_kernel and leave the CPU in a
    136 * quiesecent loop within the kernel text. The memory containing
    137 * this loop must not be re-used for anything else as the 'stuck'
    138 * core is executing it.
    139 *
    140 * This function is used to inhibit features like kexec and hibernate.
    141 */
    142bool cpus_are_stuck_in_kernel(void);
    143
    144extern void crash_smp_send_stop(void);
    145extern bool smp_crash_stop_failed(void);
    146extern void panic_smp_self_stop(void);
    147
    148#endif /* ifndef __ASSEMBLY__ */
    149
    150#endif /* ifndef __ASM_SMP_H */