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_phys_pkg_id(u32 cpuid_apic, int index_msb) { return 0; }
33static u32 noop_get_apic_id(u32 apicid) { return 0; }
34static void noop_apic_eoi(void) { }
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
35
36static u32 noop_apic_read(u32 reg)
37{
38	WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !apic_is_disabled);
39	return 0;
40}
41
42static void noop_apic_write(u32 reg, u32 val)
43{
44	WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !apic_is_disabled);
45}
46
47struct apic apic_noop __ro_after_init = {
48	.name				= "noop",
 
 
49
50	.dest_mode_logical		= true,
 
51
52	.disable_esr			= 0,
 
 
53
 
 
 
54	.check_apicid_used		= default_check_apicid_used,
 
 
 
 
55	.ioapic_phys_id_map		= default_ioapic_phys_id_map,
 
 
56	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
 
 
 
57
58	.phys_pkg_id			= noop_phys_pkg_id,
59
60	.max_apic_id			= 0xFE,
61	.get_apic_id			= noop_get_apic_id,
 
62
63	.calc_dest_apicid		= apic_flat_calc_apicid,
64
65	.send_IPI			= noop_send_IPI,
66	.send_IPI_mask			= noop_send_IPI_mask,
67	.send_IPI_mask_allbutself	= noop_send_IPI_mask_allbutself,
68	.send_IPI_allbutself		= noop_send_IPI_allbutself,
69	.send_IPI_all			= noop_send_IPI_all,
70	.send_IPI_self			= noop_send_IPI_self,
71
72	.wakeup_secondary_cpu		= noop_wakeup_secondary_cpu,
73
 
 
74	.read				= noop_apic_read,
75	.write				= noop_apic_write,
76	.eoi				= noop_apic_eoi,
77	.icr_read			= noop_apic_icr_read,
78	.icr_write			= noop_apic_icr_write,
 
 
 
 
 
 
79};

 
  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};