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};

 
  1/*
  2 * NOOP APIC driver.
  3 *
  4 * Does almost nothing and should be substituted by a real apic driver via
  5 * probe routine.
  6 *
  7 * Though in case if apic is disabled (for some reason) we try
  8 * to not uglify the caller's code and allow to call (some) apic routines
  9 * like self-ipi, etc...
 10 */
 
 
 11
 12#include <linux/threads.h>
 13#include <linux/cpumask.h>
 14#include <linux/string.h>
 15#include <linux/kernel.h>
 16#include <linux/ctype.h>
 17#include <linux/errno.h>
 18#include <asm/fixmap.h>
 19#include <asm/mpspec.h>
 20#include <asm/apicdef.h>
 21#include <asm/apic.h>
 22#include <asm/setup.h>
 23
 24#include <linux/smp.h>
 25#include <asm/ipi.h>
 26
 27#include <linux/interrupt.h>
 28#include <asm/acpi.h>
 29#include <asm/e820.h>
 30
 31static void noop_init_apic_ldr(void) { }
 32static void noop_send_IPI(int cpu, int vector) { }
 33static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { }
 34static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { }
 35static void noop_send_IPI_allbutself(int vector) { }
 36static void noop_send_IPI_all(int vector) { }
 37static void noop_send_IPI_self(int vector) { }
 38static void noop_apic_wait_icr_idle(void) { }
 39static void noop_apic_icr_write(u32 low, u32 id) { }
 40
 41static int noop_wakeup_secondary_cpu(int apicid, unsigned long start_eip)
 42{
 43	return -1;
 44}
 45
 46static u32 noop_safe_apic_wait_icr_idle(void)
 47{
 48	return 0;
 49}
 50
 51static u64 noop_apic_icr_read(void)
 52{
 53	return 0;
 54}
 55
 56static int noop_phys_pkg_id(int cpuid_apic, int index_msb)
 57{
 58	return 0;
 59}
 60
 61static unsigned int noop_get_apic_id(unsigned long x)
 62{
 63	return 0;
 64}
 65
 66static int noop_probe(void)
 67{
 68	/*
 69	 * NOOP apic should not ever be
 70	 * enabled via probe routine
 71	 */
 72	return 0;
 73}
 74
 75static int noop_apic_id_registered(void)
 76{
 77	/*
 78	 * if we would be really "pedantic"
 79	 * we should pass read_apic_id() here
 80	 * but since NOOP suppose APIC ID = 0
 81	 * lets save a few cycles
 82	 */
 83	return physid_isset(0, phys_cpu_present_map);
 84}
 85
 86static const struct cpumask *noop_target_cpus(void)
 87{
 88	/* only BSP here */
 89	return cpumask_of(0);
 90}
 91
 92static void noop_vector_allocation_domain(int cpu, struct cpumask *retmask,
 93					  const struct cpumask *mask)
 94{
 95	if (cpu != 0)
 96		pr_warning("APIC: Vector allocated for non-BSP cpu\n");
 97	cpumask_copy(retmask, cpumask_of(cpu));
 98}
 99
100static u32 noop_apic_read(u32 reg)
101{
102	WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !disable_apic);
103	return 0;
104}
105
106static void noop_apic_write(u32 reg, u32 v)
107{
108	WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !disable_apic);
109}
110
 
 
 
 
 
 
 
111struct apic apic_noop __ro_after_init = {
112	.name				= "noop",
113	.probe				= noop_probe,
114	.acpi_madt_oem_check		= NULL,
115
116	.apic_id_valid			= default_apic_id_valid,
117	.apic_id_registered		= noop_apic_id_registered,
118
119	.irq_delivery_mode		= dest_LowestPrio,
120	/* logical delivery broadcast to all CPUs: */
121	.irq_dest_mode			= 1,
122
123	.target_cpus			= noop_target_cpus,
124	.disable_esr			= 0,
125	.dest_logical			= APIC_DEST_LOGICAL,
126	.check_apicid_used		= default_check_apicid_used,
127
128	.vector_allocation_domain	= noop_vector_allocation_domain,
129	.init_apic_ldr			= noop_init_apic_ldr,
130
131	.ioapic_phys_id_map		= default_ioapic_phys_id_map,
132	.setup_apic_routing		= NULL,
133
134	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
135	.apicid_to_cpu_present		= physid_set_mask_of_physid,
136
137	.check_phys_apicid_present	= default_check_phys_apicid_present,
138
139	.phys_pkg_id			= noop_phys_pkg_id,
140
141	.get_apic_id			= noop_get_apic_id,
142	.set_apic_id			= NULL,
143
144	.cpu_mask_to_apicid_and		= flat_cpu_mask_to_apicid_and,
145
146	.send_IPI			= noop_send_IPI,
147	.send_IPI_mask			= noop_send_IPI_mask,
148	.send_IPI_mask_allbutself	= noop_send_IPI_mask_allbutself,
149	.send_IPI_allbutself		= noop_send_IPI_allbutself,
150	.send_IPI_all			= noop_send_IPI_all,
151	.send_IPI_self			= noop_send_IPI_self,
152
153	.wakeup_secondary_cpu		= noop_wakeup_secondary_cpu,
154
155	.inquire_remote_apic		= NULL,
156
157	.read				= noop_apic_read,
158	.write				= noop_apic_write,
159	.eoi_write			= noop_apic_write,
160	.icr_read			= noop_apic_icr_read,
161	.icr_write			= noop_apic_icr_write,
162	.wait_icr_idle			= noop_apic_wait_icr_idle,
163	.safe_wait_icr_idle		= noop_safe_apic_wait_icr_idle,
164
165#ifdef CONFIG_X86_32
166	.x86_32_early_logical_apicid	= noop_x86_32_early_logical_apicid,
167#endif
168};