1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2004 James Cleverdon, IBM.
4 *
5 * Flat APIC subarch code.
6 *
7 * Hacked for x86-64 by James Cleverdon from i386 architecture code by
8 * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
9 * James Cleverdon.
10 */
11#include <linux/cpumask.h>
12#include <linux/export.h>
13#include <linux/acpi.h>
14
15#include <asm/jailhouse_para.h>
16#include <asm/apic.h>
17
18#include "local.h"
19
20static struct apic apic_physflat;
21static struct apic apic_flat;
22
23struct apic *apic __ro_after_init = &apic_flat;
24EXPORT_SYMBOL_GPL(apic);
25
26static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
27{
28 return 1;
29}
30
31static void _flat_send_IPI_mask(unsigned long mask, int vector)
32{
33 unsigned long flags;
34
35 local_irq_save(flags);
36 __default_send_IPI_dest_field(mask, vector, APIC_DEST_LOGICAL);
37 local_irq_restore(flags);
38}
39
40static void flat_send_IPI_mask(const struct cpumask *cpumask, int vector)
41{
42 unsigned long mask = cpumask_bits(cpumask)[0];
43
44 _flat_send_IPI_mask(mask, vector);
45}
46
47static void
48flat_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector)
49{
50 unsigned long mask = cpumask_bits(cpumask)[0];
51 int cpu = smp_processor_id();
52
53 if (cpu < BITS_PER_LONG)
54 __clear_bit(cpu, &mask);
55
56 _flat_send_IPI_mask(mask, vector);
57}
58
59static u32 flat_get_apic_id(u32 x)
60{
61 return (x >> 24) & 0xFF;
62}
63
64static u32 set_apic_id(u32 id)
65{
66 return (id & 0xFF) << 24;
67}
68
69static u32 flat_phys_pkg_id(u32 initial_apic_id, int index_msb)
70{
71 return initial_apic_id >> index_msb;
72}
73
74static int flat_probe(void)
75{
76 return 1;
77}
78
79static struct apic apic_flat __ro_after_init = {
80 .name = "flat",
81 .probe = flat_probe,
82 .acpi_madt_oem_check = flat_acpi_madt_oem_check,
83 .apic_id_registered = default_apic_id_registered,
84
85 .delivery_mode = APIC_DELIVERY_MODE_FIXED,
86 .dest_mode_logical = true,
87
88 .disable_esr = 0,
89
90 .init_apic_ldr = default_init_apic_ldr,
91 .cpu_present_to_apicid = default_cpu_present_to_apicid,
92 .phys_pkg_id = flat_phys_pkg_id,
93
94 .max_apic_id = 0xFE,
95 .get_apic_id = flat_get_apic_id,
96 .set_apic_id = set_apic_id,
97
98 .calc_dest_apicid = apic_flat_calc_apicid,
99
100 .send_IPI = default_send_IPI_single,
101 .send_IPI_mask = flat_send_IPI_mask,
102 .send_IPI_mask_allbutself = flat_send_IPI_mask_allbutself,
103 .send_IPI_allbutself = default_send_IPI_allbutself,
104 .send_IPI_all = default_send_IPI_all,
105 .send_IPI_self = default_send_IPI_self,
106 .nmi_to_offline_cpu = true,
107
108 .read = native_apic_mem_read,
109 .write = native_apic_mem_write,
110 .eoi = native_apic_mem_eoi,
111 .icr_read = native_apic_icr_read,
112 .icr_write = native_apic_icr_write,
113 .wait_icr_idle = apic_mem_wait_icr_idle,
114 .safe_wait_icr_idle = apic_mem_wait_icr_idle_timeout,
115};
116
117/*
118 * Physflat mode is used when there are more than 8 CPUs on a system.
119 * We cannot use logical delivery in this case because the mask
120 * overflows, so use physical mode.
121 */
122static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
123{
124#ifdef CONFIG_ACPI
125 /*
126 * Quirk: some x86_64 machines can only use physical APIC mode
127 * regardless of how many processors are present (x86_64 ES7000
128 * is an example).
129 */
130 if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
131 (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
132 printk(KERN_DEBUG "system APIC only can use physical flat");
133 return 1;
134 }
135
136 if (!strncmp(oem_id, "IBM", 3) && !strncmp(oem_table_id, "EXA", 3)) {
137 printk(KERN_DEBUG "IBM Summit detected, will use apic physical");
138 return 1;
139 }
140#endif
141
142 return 0;
143}
144
145static int physflat_probe(void)
146{
147 return apic == &apic_physflat || num_possible_cpus() > 8 || jailhouse_paravirt();
148}
149
150static struct apic apic_physflat __ro_after_init = {
151
152 .name = "physical flat",
153 .probe = physflat_probe,
154 .acpi_madt_oem_check = physflat_acpi_madt_oem_check,
155 .apic_id_registered = default_apic_id_registered,
156
157 .delivery_mode = APIC_DELIVERY_MODE_FIXED,
158 .dest_mode_logical = false,
159
160 .disable_esr = 0,
161
162 .cpu_present_to_apicid = default_cpu_present_to_apicid,
163 .phys_pkg_id = flat_phys_pkg_id,
164
165 .max_apic_id = 0xFE,
166 .get_apic_id = flat_get_apic_id,
167 .set_apic_id = set_apic_id,
168
169 .calc_dest_apicid = apic_default_calc_apicid,
170
171 .send_IPI = default_send_IPI_single_phys,
172 .send_IPI_mask = default_send_IPI_mask_sequence_phys,
173 .send_IPI_mask_allbutself = default_send_IPI_mask_allbutself_phys,
174 .send_IPI_allbutself = default_send_IPI_allbutself,
175 .send_IPI_all = default_send_IPI_all,
176 .send_IPI_self = default_send_IPI_self,
177 .nmi_to_offline_cpu = true,
178
179 .read = native_apic_mem_read,
180 .write = native_apic_mem_write,
181 .eoi = native_apic_mem_eoi,
182 .icr_read = native_apic_icr_read,
183 .icr_write = native_apic_icr_write,
184 .wait_icr_idle = apic_mem_wait_icr_idle,
185 .safe_wait_icr_idle = apic_mem_wait_icr_idle_timeout,
186};
187
188/*
189 * We need to check for physflat first, so this order is important.
190 */
191apic_drivers(apic_physflat, apic_flat);
192

source code of linux/arch/x86/kernel/apic/apic_flat_64.c