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
20 static struct apic apic_physflat;
21 static struct apic apic_flat;
22
23 struct apic *apic __ro_after_init = &apic_flat;
24 EXPORT_SYMBOL_GPL(apic);
25
26 static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
27 {
28 return 1;
29 }
30
31 static 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
40 static 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
47 static void
48 flat_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
59 static u32 flat_get_apic_id(u32 x)
60 {
61 return (x >> 24) & 0xFF;
62 }
63
64 static int flat_probe(void)
65 {
66 return 1;
67 }
68
69 static struct apic apic_flat __ro_after_init = {
70 .name = "flat",
71 .probe = flat_probe,
72 .acpi_madt_oem_check = flat_acpi_madt_oem_check,
73
74 .dest_mode_logical = true,
75
76 .disable_esr = 0,
77
78 .init_apic_ldr = default_init_apic_ldr,
79 .cpu_present_to_apicid = default_cpu_present_to_apicid,
80
81 .max_apic_id = 0xFE,
82 .get_apic_id = flat_get_apic_id,
83
84 .calc_dest_apicid = apic_flat_calc_apicid,
85
86 .send_IPI = default_send_IPI_single,
87 .send_IPI_mask = flat_send_IPI_mask,
88 .send_IPI_mask_allbutself = flat_send_IPI_mask_allbutself,
89 .send_IPI_allbutself = default_send_IPI_allbutself,
90 .send_IPI_all = default_send_IPI_all,
91 .send_IPI_self = default_send_IPI_self,
92 .nmi_to_offline_cpu = true,
93
94 .read = native_apic_mem_read,
95 .write = native_apic_mem_write,
96 .eoi = native_apic_mem_eoi,
97 .icr_read = native_apic_icr_read,
98 .icr_write = native_apic_icr_write,
99 .wait_icr_idle = apic_mem_wait_icr_idle,
100 .safe_wait_icr_idle = apic_mem_wait_icr_idle_timeout,
101 };
102
103 /*
104 * Physflat mode is used when there are more than 8 CPUs on a system.
105 * We cannot use logical delivery in this case because the mask
106 * overflows, so use physical mode.
107 */
108 static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
109 {
110 #ifdef CONFIG_ACPI
111 /*
112 * Quirk: some x86_64 machines can only use physical APIC mode
113 * regardless of how many processors are present (x86_64 ES7000
114 * is an example).
115 */
116 if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
117 (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
118 printk(KERN_DEBUG "system APIC only can use physical flat");
119 return 1;
120 }
121
122 if (!strncmp(oem_id, "IBM", 3) && !strncmp(oem_table_id, "EXA", 3)) {
123 printk(KERN_DEBUG "IBM Summit detected, will use apic physical");
124 return 1;
125 }
126 #endif
127
128 return 0;
129 }
130
131 static int physflat_probe(void)
132 {
133 return apic == &apic_physflat || num_possible_cpus() > 8 || jailhouse_paravirt();
134 }
135
136 static struct apic apic_physflat __ro_after_init = {
137
138 .name = "physical flat",
139 .probe = physflat_probe,
140 .acpi_madt_oem_check = physflat_acpi_madt_oem_check,
141
142 .dest_mode_logical = false,
143
144 .disable_esr = 0,
145
146 .cpu_present_to_apicid = default_cpu_present_to_apicid,
147
148 .max_apic_id = 0xFE,
149 .get_apic_id = flat_get_apic_id,
150
151 .calc_dest_apicid = apic_default_calc_apicid,
152
153 .send_IPI = default_send_IPI_single_phys,
154 .send_IPI_mask = default_send_IPI_mask_sequence_phys,
155 .send_IPI_mask_allbutself = default_send_IPI_mask_allbutself_phys,
156 .send_IPI_allbutself = default_send_IPI_allbutself,
157 .send_IPI_all = default_send_IPI_all,
158 .send_IPI_self = default_send_IPI_self,
159 .nmi_to_offline_cpu = true,
160
161 .read = native_apic_mem_read,
162 .write = native_apic_mem_write,
163 .eoi = native_apic_mem_eoi,
164 .icr_read = native_apic_icr_read,
165 .icr_write = native_apic_icr_write,
166 .wait_icr_idle = apic_mem_wait_icr_idle,
167 .safe_wait_icr_idle = apic_mem_wait_icr_idle_timeout,
168 };
169
170 /*
171 * We need to check for physflat first, so this order is important.
172 */
173 apic_drivers(apic_physflat, apic_flat);
174
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.