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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/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_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 unsigned long noop_check_apicid_used(physid_mask_t *map, int apicid)
93{
94 return physid_isset(apicid, *map);
95}
96
97static unsigned long noop_check_apicid_present(int bit)
98{
99 return physid_isset(bit, phys_cpu_present_map);
100}
101
102static void noop_vector_allocation_domain(int cpu, struct cpumask *retmask,
103 const struct cpumask *mask)
104{
105 if (cpu != 0)
106 pr_warning("APIC: Vector allocated for non-BSP cpu\n");
107 cpumask_copy(retmask, cpumask_of(cpu));
108}
109
110static u32 noop_apic_read(u32 reg)
111{
112 WARN_ON_ONCE((cpu_has_apic && !disable_apic));
113 return 0;
114}
115
116static void noop_apic_write(u32 reg, u32 v)
117{
118 WARN_ON_ONCE(cpu_has_apic && !disable_apic);
119}
120
121struct apic apic_noop = {
122 .name = "noop",
123 .probe = noop_probe,
124 .acpi_madt_oem_check = NULL,
125
126 .apic_id_valid = default_apic_id_valid,
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_and = flat_cpu_mask_to_apicid_and,
162
163 .send_IPI_mask = noop_send_IPI_mask,
164 .send_IPI_mask_allbutself = noop_send_IPI_mask_allbutself,
165 .send_IPI_allbutself = noop_send_IPI_allbutself,
166 .send_IPI_all = noop_send_IPI_all,
167 .send_IPI_self = noop_send_IPI_self,
168
169 .wakeup_secondary_cpu = noop_wakeup_secondary_cpu,
170
171 /* should be safe */
172 .trampoline_phys_low = DEFAULT_TRAMPOLINE_PHYS_LOW,
173 .trampoline_phys_high = DEFAULT_TRAMPOLINE_PHYS_HIGH,
174
175 .wait_for_init_deassert = false,
176 .smp_callin_clear_local_apic = NULL,
177 .inquire_remote_apic = NULL,
178
179 .read = noop_apic_read,
180 .write = noop_apic_write,
181 .eoi_write = noop_apic_write,
182 .icr_read = noop_apic_icr_read,
183 .icr_write = noop_apic_icr_write,
184 .wait_icr_idle = noop_apic_wait_icr_idle,
185 .safe_wait_icr_idle = noop_safe_apic_wait_icr_idle,
186
187#ifdef CONFIG_X86_32
188 .x86_32_early_logical_apicid = noop_x86_32_early_logical_apicid,
189#endif
190};