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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#include <linux/cpumask.h>
13
14#include <asm/apic.h>
15
16static void noop_init_apic_ldr(void) { }
17static void noop_send_IPI(int cpu, int vector) { }
18static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { }
19static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { }
20static void noop_send_IPI_allbutself(int vector) { }
21static void noop_send_IPI_all(int vector) { }
22static void noop_send_IPI_self(int vector) { }
23static void noop_apic_wait_icr_idle(void) { }
24static void noop_apic_icr_write(u32 low, u32 id) { }
25
26static int noop_wakeup_secondary_cpu(int apicid, unsigned long start_eip)
27{
28 return -1;
29}
30
31static u32 noop_safe_apic_wait_icr_idle(void)
32{
33 return 0;
34}
35
36static u64 noop_apic_icr_read(void)
37{
38 return 0;
39}
40
41static int noop_phys_pkg_id(int cpuid_apic, int index_msb)
42{
43 return 0;
44}
45
46static unsigned int noop_get_apic_id(unsigned long x)
47{
48 return 0;
49}
50
51static int noop_probe(void)
52{
53 /*
54 * NOOP apic should not ever be
55 * enabled via probe routine
56 */
57 return 0;
58}
59
60static int noop_apic_id_registered(void)
61{
62 /*
63 * if we would be really "pedantic"
64 * we should pass read_apic_id() here
65 * but since NOOP suppose APIC ID = 0
66 * lets save a few cycles
67 */
68 return physid_isset(0, phys_cpu_present_map);
69}
70
71static u32 noop_apic_read(u32 reg)
72{
73 WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !disable_apic);
74 return 0;
75}
76
77static void noop_apic_write(u32 reg, u32 v)
78{
79 WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !disable_apic);
80}
81
82#ifdef CONFIG_X86_32
83static int noop_x86_32_early_logical_apicid(int cpu)
84{
85 return BAD_APICID;
86}
87#endif
88
89struct apic apic_noop __ro_after_init = {
90 .name = "noop",
91 .probe = noop_probe,
92 .acpi_madt_oem_check = NULL,
93
94 .apic_id_valid = default_apic_id_valid,
95 .apic_id_registered = noop_apic_id_registered,
96
97 .irq_delivery_mode = dest_Fixed,
98 /* logical delivery broadcast to all CPUs: */
99 .irq_dest_mode = 1,
100
101 .disable_esr = 0,
102 .dest_logical = APIC_DEST_LOGICAL,
103 .check_apicid_used = default_check_apicid_used,
104
105 .init_apic_ldr = noop_init_apic_ldr,
106
107 .ioapic_phys_id_map = default_ioapic_phys_id_map,
108 .setup_apic_routing = NULL,
109
110 .cpu_present_to_apicid = default_cpu_present_to_apicid,
111 .apicid_to_cpu_present = physid_set_mask_of_physid,
112
113 .check_phys_apicid_present = default_check_phys_apicid_present,
114
115 .phys_pkg_id = noop_phys_pkg_id,
116
117 .get_apic_id = noop_get_apic_id,
118 .set_apic_id = NULL,
119
120 .calc_dest_apicid = apic_flat_calc_apicid,
121
122 .send_IPI = noop_send_IPI,
123 .send_IPI_mask = noop_send_IPI_mask,
124 .send_IPI_mask_allbutself = noop_send_IPI_mask_allbutself,
125 .send_IPI_allbutself = noop_send_IPI_allbutself,
126 .send_IPI_all = noop_send_IPI_all,
127 .send_IPI_self = noop_send_IPI_self,
128
129 .wakeup_secondary_cpu = noop_wakeup_secondary_cpu,
130
131 .inquire_remote_apic = NULL,
132
133 .read = noop_apic_read,
134 .write = noop_apic_write,
135 .eoi_write = noop_apic_write,
136 .icr_read = noop_apic_icr_read,
137 .icr_write = noop_apic_icr_write,
138 .wait_icr_idle = noop_apic_wait_icr_idle,
139 .safe_wait_icr_idle = noop_safe_apic_wait_icr_idle,
140
141#ifdef CONFIG_X86_32
142 .x86_32_early_logical_apicid = noop_x86_32_early_logical_apicid,
143#endif
144};
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};