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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apic_noop.c (3467B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * NOOP APIC driver.
      4 *
      5 * Does almost nothing and should be substituted by a real apic driver via
      6 * probe routine.
      7 *
      8 * Though in case if apic is disabled (for some reason) we try
      9 * to not uglify the caller's code and allow to call (some) apic routines
     10 * like self-ipi, etc...
     11 */
     12#include <linux/cpumask.h>
     13#include <linux/thread_info.h>
     14
     15#include <asm/apic.h>
     16
     17static void noop_init_apic_ldr(void) { }
     18static void noop_send_IPI(int cpu, int vector) { }
     19static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { }
     20static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { }
     21static void noop_send_IPI_allbutself(int vector) { }
     22static void noop_send_IPI_all(int vector) { }
     23static void noop_send_IPI_self(int vector) { }
     24static void noop_apic_wait_icr_idle(void) { }
     25static void noop_apic_icr_write(u32 low, u32 id) { }
     26
     27static int noop_wakeup_secondary_cpu(int apicid, unsigned long start_eip)
     28{
     29	return -1;
     30}
     31
     32static u32 noop_safe_apic_wait_icr_idle(void)
     33{
     34	return 0;
     35}
     36
     37static u64 noop_apic_icr_read(void)
     38{
     39	return 0;
     40}
     41
     42static int noop_phys_pkg_id(int cpuid_apic, int index_msb)
     43{
     44	return 0;
     45}
     46
     47static unsigned int noop_get_apic_id(unsigned long x)
     48{
     49	return 0;
     50}
     51
     52static int noop_probe(void)
     53{
     54	/*
     55	 * NOOP apic should not ever be
     56	 * enabled via probe routine
     57	 */
     58	return 0;
     59}
     60
     61static int noop_apic_id_registered(void)
     62{
     63	/*
     64	 * if we would be really "pedantic"
     65	 * we should pass read_apic_id() here
     66	 * but since NOOP suppose APIC ID = 0
     67	 * lets save a few cycles
     68	 */
     69	return physid_isset(0, phys_cpu_present_map);
     70}
     71
     72static u32 noop_apic_read(u32 reg)
     73{
     74	WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !disable_apic);
     75	return 0;
     76}
     77
     78static void noop_apic_write(u32 reg, u32 v)
     79{
     80	WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !disable_apic);
     81}
     82
     83#ifdef CONFIG_X86_32
     84static int noop_x86_32_early_logical_apicid(int cpu)
     85{
     86	return BAD_APICID;
     87}
     88#endif
     89
     90struct apic apic_noop __ro_after_init = {
     91	.name				= "noop",
     92	.probe				= noop_probe,
     93	.acpi_madt_oem_check		= NULL,
     94
     95	.apic_id_valid			= default_apic_id_valid,
     96	.apic_id_registered		= noop_apic_id_registered,
     97
     98	.delivery_mode			= APIC_DELIVERY_MODE_FIXED,
     99	.dest_mode_logical		= true,
    100
    101	.disable_esr			= 0,
    102
    103	.check_apicid_used		= default_check_apicid_used,
    104	.init_apic_ldr			= noop_init_apic_ldr,
    105	.ioapic_phys_id_map		= default_ioapic_phys_id_map,
    106	.setup_apic_routing		= NULL,
    107	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
    108	.apicid_to_cpu_present		= physid_set_mask_of_physid,
    109
    110	.check_phys_apicid_present	= default_check_phys_apicid_present,
    111
    112	.phys_pkg_id			= noop_phys_pkg_id,
    113
    114	.get_apic_id			= noop_get_apic_id,
    115	.set_apic_id			= NULL,
    116
    117	.calc_dest_apicid		= apic_flat_calc_apicid,
    118
    119	.send_IPI			= noop_send_IPI,
    120	.send_IPI_mask			= noop_send_IPI_mask,
    121	.send_IPI_mask_allbutself	= noop_send_IPI_mask_allbutself,
    122	.send_IPI_allbutself		= noop_send_IPI_allbutself,
    123	.send_IPI_all			= noop_send_IPI_all,
    124	.send_IPI_self			= noop_send_IPI_self,
    125
    126	.wakeup_secondary_cpu		= noop_wakeup_secondary_cpu,
    127
    128	.inquire_remote_apic		= NULL,
    129
    130	.read				= noop_apic_read,
    131	.write				= noop_apic_write,
    132	.eoi_write			= noop_apic_write,
    133	.icr_read			= noop_apic_icr_read,
    134	.icr_write			= noop_apic_icr_write,
    135	.wait_icr_idle			= noop_apic_wait_icr_idle,
    136	.safe_wait_icr_idle		= noop_safe_apic_wait_icr_idle,
    137
    138#ifdef CONFIG_X86_32
    139	.x86_32_early_logical_apicid	= noop_x86_32_early_logical_apicid,
    140#endif
    141};