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/module.h>
 15#include <linux/string.h>
 16#include <linux/kernel.h>
 17#include <linux/ctype.h>
 18#include <linux/errno.h>
 19#include <asm/fixmap.h>
 20#include <asm/mpspec.h>
 21#include <asm/apicdef.h>
 22#include <asm/apic.h>
 23#include <asm/setup.h>
 24
 25#include <linux/smp.h>
 26#include <asm/ipi.h>
 27
 28#include <linux/interrupt.h>
 29#include <asm/acpi.h>
 30#include <asm/e820.h>
 31
 32static void noop_init_apic_ldr(void) { }
 33static void noop_send_IPI(int cpu, int vector) { }
 34static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { }
 35static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { }
 36static void noop_send_IPI_allbutself(int vector) { }
 37static void noop_send_IPI_all(int vector) { }
 38static void noop_send_IPI_self(int vector) { }
 39static void noop_apic_wait_icr_idle(void) { }
 40static void noop_apic_icr_write(u32 low, u32 id) { }
 41
 42static int noop_wakeup_secondary_cpu(int apicid, unsigned long start_eip)
 43{
 44	return -1;
 45}
 46
 47static u32 noop_safe_apic_wait_icr_idle(void)
 48{
 49	return 0;
 50}
 51
 52static u64 noop_apic_icr_read(void)
 53{
 54	return 0;
 55}
 56
 57static int noop_phys_pkg_id(int cpuid_apic, int index_msb)
 58{
 59	return 0;
 60}
 61
 62static unsigned int noop_get_apic_id(unsigned long x)
 63{
 64	return 0;
 65}
 66
 67static int noop_probe(void)
 68{
 69	/*
 70	 * NOOP apic should not ever be
 71	 * enabled via probe routine
 72	 */
 73	return 0;
 74}
 75
 76static int noop_apic_id_registered(void)
 77{
 78	/*
 79	 * if we would be really "pedantic"
 80	 * we should pass read_apic_id() here
 81	 * but since NOOP suppose APIC ID = 0
 82	 * lets save a few cycles
 83	 */
 84	return physid_isset(0, phys_cpu_present_map);
 85}
 86
 87static const struct cpumask *noop_target_cpus(void)
 88{
 89	/* only BSP here */
 90	return cpumask_of(0);
 91}
 92
 93static void noop_vector_allocation_domain(int cpu, struct cpumask *retmask,
 94					  const struct cpumask *mask)
 95{
 96	if (cpu != 0)
 97		pr_warning("APIC: Vector allocated for non-BSP cpu\n");
 98	cpumask_copy(retmask, cpumask_of(cpu));
 99}
100
101static u32 noop_apic_read(u32 reg)
 
102{
103	WARN_ON_ONCE((cpu_has_apic && !disable_apic));
104	return 0;
105}
 
106
107static void noop_apic_write(u32 reg, u32 v)
108{
109	WARN_ON_ONCE(cpu_has_apic && !disable_apic);
110}
111
112struct apic apic_noop = {
113	.name				= "noop",
114	.probe				= noop_probe,
115	.acpi_madt_oem_check		= NULL,
116
117	.apic_id_valid			= default_apic_id_valid,
118	.apic_id_registered		= noop_apic_id_registered,
119
120	.irq_delivery_mode		= dest_LowestPrio,
121	/* logical delivery broadcast to all CPUs: */
122	.irq_dest_mode			= 1,
123
124	.target_cpus			= noop_target_cpus,
125	.disable_esr			= 0,
126	.dest_logical			= APIC_DEST_LOGICAL,
127	.check_apicid_used		= default_check_apicid_used,
128
129	.vector_allocation_domain	= noop_vector_allocation_domain,
130	.init_apic_ldr			= noop_init_apic_ldr,
131
132	.ioapic_phys_id_map		= default_ioapic_phys_id_map,
133	.setup_apic_routing		= NULL,
134
135	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
136	.apicid_to_cpu_present		= physid_set_mask_of_physid,
137
138	.check_phys_apicid_present	= default_check_phys_apicid_present,
139
140	.phys_pkg_id			= noop_phys_pkg_id,
141
142	.get_apic_id			= noop_get_apic_id,
143	.set_apic_id			= NULL,
144	.apic_id_mask			= 0x0F << 24,
145
146	.cpu_mask_to_apicid_and		= flat_cpu_mask_to_apicid_and,
147
148	.send_IPI			= noop_send_IPI,
149	.send_IPI_mask			= noop_send_IPI_mask,
150	.send_IPI_mask_allbutself	= noop_send_IPI_mask_allbutself,
151	.send_IPI_allbutself		= noop_send_IPI_allbutself,
152	.send_IPI_all			= noop_send_IPI_all,
153	.send_IPI_self			= noop_send_IPI_self,
154
155	.wakeup_secondary_cpu		= noop_wakeup_secondary_cpu,
156
157	.inquire_remote_apic		= NULL,
158
159	.read				= noop_apic_read,
160	.write				= noop_apic_write,
161	.eoi_write			= noop_apic_write,
162	.icr_read			= noop_apic_icr_read,
163	.icr_write			= noop_apic_icr_write,
164	.wait_icr_idle			= noop_apic_wait_icr_idle,
165	.safe_wait_icr_idle		= noop_safe_apic_wait_icr_idle,
166
167#ifdef CONFIG_X86_32
168	.x86_32_early_logical_apicid	= noop_x86_32_early_logical_apicid,
169#endif
170};