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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cpu_ops.c (2641B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * CPU kernel entry/exit control
      4 *
      5 * Copyright (C) 2013 ARM Ltd.
      6 */
      7
      8#include <linux/acpi.h>
      9#include <linux/cache.h>
     10#include <linux/errno.h>
     11#include <linux/of.h>
     12#include <linux/string.h>
     13#include <asm/acpi.h>
     14#include <asm/cpu_ops.h>
     15#include <asm/smp_plat.h>
     16
     17extern const struct cpu_operations smp_spin_table_ops;
     18#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
     19extern const struct cpu_operations acpi_parking_protocol_ops;
     20#endif
     21extern const struct cpu_operations cpu_psci_ops;
     22
     23static const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
     24
     25static const struct cpu_operations *const dt_supported_cpu_ops[] __initconst = {
     26	&smp_spin_table_ops,
     27	&cpu_psci_ops,
     28	NULL,
     29};
     30
     31static const struct cpu_operations *const acpi_supported_cpu_ops[] __initconst = {
     32#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
     33	&acpi_parking_protocol_ops,
     34#endif
     35	&cpu_psci_ops,
     36	NULL,
     37};
     38
     39static const struct cpu_operations * __init cpu_get_ops(const char *name)
     40{
     41	const struct cpu_operations *const *ops;
     42
     43	ops = acpi_disabled ? dt_supported_cpu_ops : acpi_supported_cpu_ops;
     44
     45	while (*ops) {
     46		if (!strcmp(name, (*ops)->name))
     47			return *ops;
     48
     49		ops++;
     50	}
     51
     52	return NULL;
     53}
     54
     55static const char *__init cpu_read_enable_method(int cpu)
     56{
     57	const char *enable_method;
     58
     59	if (acpi_disabled) {
     60		struct device_node *dn = of_get_cpu_node(cpu, NULL);
     61
     62		if (!dn) {
     63			if (!cpu)
     64				pr_err("Failed to find device node for boot cpu\n");
     65			return NULL;
     66		}
     67
     68		enable_method = of_get_property(dn, "enable-method", NULL);
     69		if (!enable_method) {
     70			/*
     71			 * The boot CPU may not have an enable method (e.g.
     72			 * when spin-table is used for secondaries).
     73			 * Don't warn spuriously.
     74			 */
     75			if (cpu != 0)
     76				pr_err("%pOF: missing enable-method property\n",
     77					dn);
     78		}
     79		of_node_put(dn);
     80	} else {
     81		enable_method = acpi_get_enable_method(cpu);
     82		if (!enable_method) {
     83			/*
     84			 * In ACPI systems the boot CPU does not require
     85			 * checking the enable method since for some
     86			 * boot protocol (ie parking protocol) it need not
     87			 * be initialized. Don't warn spuriously.
     88			 */
     89			if (cpu != 0)
     90				pr_err("Unsupported ACPI enable-method\n");
     91		}
     92	}
     93
     94	return enable_method;
     95}
     96/*
     97 * Read a cpu's enable method and record it in cpu_ops.
     98 */
     99int __init init_cpu_ops(int cpu)
    100{
    101	const char *enable_method = cpu_read_enable_method(cpu);
    102
    103	if (!enable_method)
    104		return -ENODEV;
    105
    106	cpu_ops[cpu] = cpu_get_ops(enable_method);
    107	if (!cpu_ops[cpu]) {
    108		pr_warn("Unsupported enable-method: %s\n", enable_method);
    109		return -EOPNOTSUPP;
    110	}
    111
    112	return 0;
    113}
    114
    115const struct cpu_operations *get_cpu_ops(int cpu)
    116{
    117	return cpu_ops[cpu];
    118}