1// SPDX-License-Identifier: GPL-2.0-only
  2#define pr_fmt(fmt) "APIC: " fmt
  3
  4#include <asm/apic.h>
  5
  6#include "local.h"
  7
  8/*
  9 * Use DEFINE_STATIC_CALL_NULL() to avoid having to provide stub functions
 10 * for each callback. The callbacks are setup during boot and all except
 11 * wait_icr_idle() must be initialized before usage. The IPI wrappers
 12 * use static_call() and not static_call_cond() to catch any fails.
 13 */
 14#define DEFINE_APIC_CALL(__cb)						\
 15	DEFINE_STATIC_CALL_NULL(apic_call_##__cb, *apic->__cb)
 16
 17DEFINE_APIC_CALL(eoi);
 18DEFINE_APIC_CALL(native_eoi);
 19DEFINE_APIC_CALL(icr_read);
 20DEFINE_APIC_CALL(icr_write);
 21DEFINE_APIC_CALL(read);
 22DEFINE_APIC_CALL(send_IPI);
 23DEFINE_APIC_CALL(send_IPI_mask);
 24DEFINE_APIC_CALL(send_IPI_mask_allbutself);
 25DEFINE_APIC_CALL(send_IPI_allbutself);
 26DEFINE_APIC_CALL(send_IPI_all);
 27DEFINE_APIC_CALL(send_IPI_self);
 28DEFINE_APIC_CALL(wait_icr_idle);
 29DEFINE_APIC_CALL(wakeup_secondary_cpu);
 30DEFINE_APIC_CALL(wakeup_secondary_cpu_64);
 31DEFINE_APIC_CALL(write);
 32
 33EXPORT_STATIC_CALL_TRAMP_GPL(apic_call_send_IPI_mask);
 34EXPORT_STATIC_CALL_TRAMP_GPL(apic_call_send_IPI_self);
 35
 36/* The container for function call overrides */
 37struct apic_override __x86_apic_override __initdata;
 38
 39#define apply_override(__cb)					\
 40	if (__x86_apic_override.__cb)				\
 41		apic->__cb = __x86_apic_override.__cb
 42
 43static __init void restore_override_callbacks(void)
 44{
 45	apply_override(eoi);
 46	apply_override(native_eoi);
 47	apply_override(write);
 48	apply_override(read);
 49	apply_override(send_IPI);
 50	apply_override(send_IPI_mask);
 51	apply_override(send_IPI_mask_allbutself);
 52	apply_override(send_IPI_allbutself);
 53	apply_override(send_IPI_all);
 54	apply_override(send_IPI_self);
 55	apply_override(icr_read);
 56	apply_override(icr_write);
 57	apply_override(wakeup_secondary_cpu);
 58	apply_override(wakeup_secondary_cpu_64);
 59}
 60
 61#define update_call(__cb)					\
 62	static_call_update(apic_call_##__cb, *apic->__cb)
 63
 64static __init void update_static_calls(void)
 65{
 66	update_call(eoi);
 67	update_call(native_eoi);
 68	update_call(write);
 69	update_call(read);
 70	update_call(send_IPI);
 71	update_call(send_IPI_mask);
 72	update_call(send_IPI_mask_allbutself);
 73	update_call(send_IPI_allbutself);
 74	update_call(send_IPI_all);
 75	update_call(send_IPI_self);
 76	update_call(icr_read);
 77	update_call(icr_write);
 78	update_call(wait_icr_idle);
 79	update_call(wakeup_secondary_cpu);
 80	update_call(wakeup_secondary_cpu_64);
 81}
 82
 83void __init apic_setup_apic_calls(void)
 84{
 85	/* Ensure that the default APIC has native_eoi populated */
 86	apic->native_eoi = apic->eoi;
 87	update_static_calls();
 88	pr_info("Static calls initialized\n");
 89}
 90
 91void __init apic_install_driver(struct apic *driver)
 92{
 93	if (apic == driver)
 94		return;
 95
 96	apic = driver;
 97
 98	if (IS_ENABLED(CONFIG_X86_X2APIC) && apic->x2apic_set_max_apicid)
 99		apic->max_apic_id = x2apic_max_apicid;
100
101	/* Copy the original eoi() callback as KVM/HyperV might overwrite it */
102	if (!apic->native_eoi)
103		apic->native_eoi = apic->eoi;
104
105	/* Apply any already installed callback overrides */
106	restore_override_callbacks();
107	update_static_calls();
108
109	pr_info("Switched APIC routing to: %s\n", driver->name);
110}