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 * FIXME: Remove this gunk. The above argument which was intentionally left
13 * in place is silly to begin with because none of the callbacks except for
14 * APIC::read/write() have a WARN_ON_ONCE() in them. Sigh...
15 */
16#include <linux/cpumask.h>
17#include <linux/thread_info.h>
18
 
 
 
 
 
 
 
 
 
 
 
19#include <asm/apic.h>
 
 
 
 
20
21#include "local.h"
 
 
22
23static void noop_send_IPI(int cpu, int vector) { }
24static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { }
25static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { }
26static void noop_send_IPI_allbutself(int vector) { }
27static void noop_send_IPI_all(int vector) { }
28static void noop_send_IPI_self(int vector) { }
 
29static void noop_apic_icr_write(u32 low, u32 id) { }
30static int noop_wakeup_secondary_cpu(u32 apicid, unsigned long start_eip) { return -1; }
31static u64 noop_apic_icr_read(void) { return 0; }
32static u32 noop_get_apic_id(u32 apicid) { return 0; }
33static void noop_apic_eoi(void) { }
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
34
35static u32 noop_apic_read(u32 reg)
36{
37	WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !apic_is_disabled);
38	return 0;
39}
40
41static void noop_apic_write(u32 reg, u32 val)
42{
43	WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !apic_is_disabled);
44}
45
46struct apic apic_noop __ro_after_init = {
47	.name				= "noop",
 
 
 
 
48
49	.dest_mode_logical		= true,
 
 
50
 
51	.disable_esr			= 0,
 
 
 
 
 
 
 
 
 
 
52
53	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
 
 
 
 
 
 
 
 
 
54
55	.max_apic_id			= 0xFE,
56	.get_apic_id			= noop_get_apic_id,
 
 
57
58	.calc_dest_apicid		= apic_flat_calc_apicid,
 
59
60	.send_IPI			= noop_send_IPI,
61	.send_IPI_mask			= noop_send_IPI_mask,
62	.send_IPI_mask_allbutself	= noop_send_IPI_mask_allbutself,
63	.send_IPI_allbutself		= noop_send_IPI_allbutself,
64	.send_IPI_all			= noop_send_IPI_all,
65	.send_IPI_self			= noop_send_IPI_self,
66
67	.wakeup_secondary_cpu		= noop_wakeup_secondary_cpu,
68
 
 
 
 
 
 
 
 
 
69	.read				= noop_apic_read,
70	.write				= noop_apic_write,
71	.eoi				= noop_apic_eoi,
72	.icr_read			= noop_apic_icr_read,
73	.icr_write			= noop_apic_icr_write,
 
 
 
 
 
 
74};

 
  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/init.h>
 19#include <linux/errno.h>
 20#include <asm/fixmap.h>
 21#include <asm/mpspec.h>
 22#include <asm/apicdef.h>
 23#include <asm/apic.h>
 24#include <asm/setup.h>
 25
 26#include <linux/smp.h>
 27#include <asm/ipi.h>
 28
 29#include <linux/interrupt.h>
 30#include <asm/acpi.h>
 31#include <asm/e820.h>
 32
 33static void noop_init_apic_ldr(void) { }
 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 unsigned long noop_check_apicid_used(physid_mask_t *map, int apicid)
 94{
 95	return physid_isset(apicid, *map);
 96}
 97
 98static unsigned long noop_check_apicid_present(int bit)
 99{
100	return physid_isset(bit, phys_cpu_present_map);
101}
102
103static void noop_vector_allocation_domain(int cpu, struct cpumask *retmask)
104{
105	if (cpu != 0)
106		pr_warning("APIC: Vector allocated for non-BSP cpu\n");
107	cpumask_clear(retmask);
108	cpumask_set_cpu(cpu, retmask);
109}
110
111static u32 noop_apic_read(u32 reg)
112{
113	WARN_ON_ONCE((cpu_has_apic && !disable_apic));
114	return 0;
115}
116
117static void noop_apic_write(u32 reg, u32 v)
118{
119	WARN_ON_ONCE(cpu_has_apic && !disable_apic);
120}
121
122struct apic apic_noop = {
123	.name				= "noop",
124	.probe				= noop_probe,
125	.acpi_madt_oem_check		= NULL,
126
127	.apic_id_registered		= noop_apic_id_registered,
128
129	.irq_delivery_mode		= dest_LowestPrio,
130	/* logical delivery broadcast to all CPUs: */
131	.irq_dest_mode			= 1,
132
133	.target_cpus			= noop_target_cpus,
134	.disable_esr			= 0,
135	.dest_logical			= APIC_DEST_LOGICAL,
136	.check_apicid_used		= noop_check_apicid_used,
137	.check_apicid_present		= noop_check_apicid_present,
138
139	.vector_allocation_domain	= noop_vector_allocation_domain,
140	.init_apic_ldr			= noop_init_apic_ldr,
141
142	.ioapic_phys_id_map		= default_ioapic_phys_id_map,
143	.setup_apic_routing		= NULL,
144	.multi_timer_check		= NULL,
145
146	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
147	.apicid_to_cpu_present		= physid_set_mask_of_physid,
148
149	.setup_portio_remap		= NULL,
150	.check_phys_apicid_present	= default_check_phys_apicid_present,
151	.enable_apic_mode		= NULL,
152
153	.phys_pkg_id			= noop_phys_pkg_id,
154
155	.mps_oem_check			= NULL,
156
 
157	.get_apic_id			= noop_get_apic_id,
158	.set_apic_id			= NULL,
159	.apic_id_mask			= 0x0F << 24,
160
161	.cpu_mask_to_apicid		= default_cpu_mask_to_apicid,
162	.cpu_mask_to_apicid_and		= default_cpu_mask_to_apicid_and,
163
 
164	.send_IPI_mask			= noop_send_IPI_mask,
165	.send_IPI_mask_allbutself	= noop_send_IPI_mask_allbutself,
166	.send_IPI_allbutself		= noop_send_IPI_allbutself,
167	.send_IPI_all			= noop_send_IPI_all,
168	.send_IPI_self			= noop_send_IPI_self,
169
170	.wakeup_secondary_cpu		= noop_wakeup_secondary_cpu,
171
172	/* should be safe */
173	.trampoline_phys_low		= DEFAULT_TRAMPOLINE_PHYS_LOW,
174	.trampoline_phys_high		= DEFAULT_TRAMPOLINE_PHYS_HIGH,
175
176	.wait_for_init_deassert		= NULL,
177
178	.smp_callin_clear_local_apic	= NULL,
179	.inquire_remote_apic		= NULL,
180
181	.read				= noop_apic_read,
182	.write				= noop_apic_write,
 
183	.icr_read			= noop_apic_icr_read,
184	.icr_write			= noop_apic_icr_write,
185	.wait_icr_idle			= noop_apic_wait_icr_idle,
186	.safe_wait_icr_idle		= noop_safe_apic_wait_icr_idle,
187
188#ifdef CONFIG_X86_32
189	.x86_32_early_logical_apicid	= noop_x86_32_early_logical_apicid,
190#endif
191};