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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Default generic APIC driver. This handles up to 8 CPUs.
4 *
5 * Copyright 2003 Andi Kleen, SuSE Labs.
6 *
7 * Generic x86 APIC driver probe layer.
8 */
9#include <linux/export.h>
10#include <linux/errno.h>
11#include <linux/smp.h>
12
13#include <asm/apic.h>
14#include <asm/acpi.h>
15
16#include "local.h"
17
18static int default_x86_32_early_logical_apicid(int cpu)
19{
20 return 1 << cpu;
21}
22
23static void setup_apic_flat_routing(void)
24{
25#ifdef CONFIG_X86_IO_APIC
26 printk(KERN_INFO
27 "Enabling APIC mode: Flat. Using %d I/O APICs\n",
28 nr_ioapics);
29#endif
30}
31
32static int default_apic_id_registered(void)
33{
34 return physid_isset(read_apic_id(), phys_cpu_present_map);
35}
36
37/*
38 * Set up the logical destination ID. Intel recommends to set DFR, LDR and
39 * TPR before enabling an APIC. See e.g. "AP-388 82489DX User's Manual"
40 * (Intel document number 292116).
41 */
42static void default_init_apic_ldr(void)
43{
44 unsigned long val;
45
46 apic_write(APIC_DFR, APIC_DFR_VALUE);
47 val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
48 val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
49 apic_write(APIC_LDR, val);
50}
51
52static int default_phys_pkg_id(int cpuid_apic, int index_msb)
53{
54 return cpuid_apic >> index_msb;
55}
56
57/* should be called last. */
58static int probe_default(void)
59{
60 return 1;
61}
62
63static struct apic apic_default __ro_after_init = {
64
65 .name = "default",
66 .probe = probe_default,
67 .acpi_madt_oem_check = NULL,
68 .apic_id_valid = default_apic_id_valid,
69 .apic_id_registered = default_apic_id_registered,
70
71 .irq_delivery_mode = dest_Fixed,
72 /* logical delivery broadcast to all CPUs: */
73 .irq_dest_mode = 1,
74
75 .disable_esr = 0,
76 .dest_logical = APIC_DEST_LOGICAL,
77 .check_apicid_used = default_check_apicid_used,
78
79 .init_apic_ldr = default_init_apic_ldr,
80
81 .ioapic_phys_id_map = default_ioapic_phys_id_map,
82 .setup_apic_routing = setup_apic_flat_routing,
83 .cpu_present_to_apicid = default_cpu_present_to_apicid,
84 .apicid_to_cpu_present = physid_set_mask_of_physid,
85 .check_phys_apicid_present = default_check_phys_apicid_present,
86 .phys_pkg_id = default_phys_pkg_id,
87
88 .get_apic_id = default_get_apic_id,
89 .set_apic_id = NULL,
90
91 .calc_dest_apicid = apic_flat_calc_apicid,
92
93 .send_IPI = default_send_IPI_single,
94 .send_IPI_mask = default_send_IPI_mask_logical,
95 .send_IPI_mask_allbutself = default_send_IPI_mask_allbutself_logical,
96 .send_IPI_allbutself = default_send_IPI_allbutself,
97 .send_IPI_all = default_send_IPI_all,
98 .send_IPI_self = default_send_IPI_self,
99
100 .inquire_remote_apic = default_inquire_remote_apic,
101
102 .read = native_apic_mem_read,
103 .write = native_apic_mem_write,
104 .eoi_write = native_apic_mem_write,
105 .icr_read = native_apic_icr_read,
106 .icr_write = native_apic_icr_write,
107 .wait_icr_idle = native_apic_wait_icr_idle,
108 .safe_wait_icr_idle = native_safe_apic_wait_icr_idle,
109
110 .x86_32_early_logical_apicid = default_x86_32_early_logical_apicid,
111};
112
113apic_driver(apic_default);
114
115struct apic *apic __ro_after_init = &apic_default;
116EXPORT_SYMBOL_GPL(apic);
117
118static int cmdline_apic __initdata;
119static int __init parse_apic(char *arg)
120{
121 struct apic **drv;
122
123 if (!arg)
124 return -EINVAL;
125
126 for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
127 if (!strcmp((*drv)->name, arg)) {
128 apic = *drv;
129 cmdline_apic = 1;
130 return 0;
131 }
132 }
133
134 /* Parsed again by __setup for debug/verbose */
135 return 0;
136}
137early_param("apic", parse_apic);
138
139void __init default_setup_apic_routing(void)
140{
141 int version = boot_cpu_apic_version;
142
143 if (num_possible_cpus() > 8) {
144 switch (boot_cpu_data.x86_vendor) {
145 case X86_VENDOR_INTEL:
146 if (!APIC_XAPIC(version)) {
147 def_to_bigsmp = 0;
148 break;
149 }
150 /* P4 and above */
151 /* fall through */
152 case X86_VENDOR_HYGON:
153 case X86_VENDOR_AMD:
154 def_to_bigsmp = 1;
155 }
156 }
157
158#ifdef CONFIG_X86_BIGSMP
159 /*
160 * This is used to switch to bigsmp mode when
161 * - There is no apic= option specified by the user
162 * - generic_apic_probe() has chosen apic_default as the sub_arch
163 * - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support
164 */
165
166 if (!cmdline_apic && apic == &apic_default)
167 generic_bigsmp_probe();
168#endif
169
170 if (apic->setup_apic_routing)
171 apic->setup_apic_routing();
172
173 if (x86_platform.apic_post_init)
174 x86_platform.apic_post_init();
175}
176
177void __init generic_apic_probe(void)
178{
179 if (!cmdline_apic) {
180 struct apic **drv;
181
182 for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
183 if ((*drv)->probe()) {
184 apic = *drv;
185 break;
186 }
187 }
188 /* Not visible without early console */
189 if (drv == __apicdrivers_end)
190 panic("Didn't find an APIC driver");
191 }
192 printk(KERN_INFO "Using APIC driver %s\n", apic->name);
193}
194
195/* This function can switch the APIC even after the initial ->probe() */
196int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
197{
198 struct apic **drv;
199
200 for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
201 if (!(*drv)->acpi_madt_oem_check)
202 continue;
203 if (!(*drv)->acpi_madt_oem_check(oem_id, oem_table_id))
204 continue;
205
206 if (!cmdline_apic) {
207 apic = *drv;
208 printk(KERN_INFO "Switched to APIC driver `%s'.\n",
209 apic->name);
210 }
211 return 1;
212 }
213 return 0;
214}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Default generic APIC driver. This handles up to 8 CPUs.
4 *
5 * Copyright 2003 Andi Kleen, SuSE Labs.
6 *
7 * Generic x86 APIC driver probe layer.
8 */
9#include <linux/export.h>
10#include <linux/errno.h>
11#include <linux/smp.h>
12
13#include <xen/xen.h>
14
15#include <asm/io_apic.h>
16#include <asm/apic.h>
17#include <asm/acpi.h>
18
19#include "local.h"
20
21static u32 default_phys_pkg_id(u32 cpuid_apic, int index_msb)
22{
23 return cpuid_apic >> index_msb;
24}
25
26static u32 default_get_apic_id(u32 x)
27{
28 unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
29
30 if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID))
31 return (x >> 24) & 0xFF;
32 else
33 return (x >> 24) & 0x0F;
34}
35
36/* should be called last. */
37static int probe_default(void)
38{
39 return 1;
40}
41
42static struct apic apic_default __ro_after_init = {
43
44 .name = "default",
45 .probe = probe_default,
46 .apic_id_registered = default_apic_id_registered,
47
48 .dest_mode_logical = true,
49
50 .disable_esr = 0,
51
52 .check_apicid_used = default_check_apicid_used,
53 .init_apic_ldr = default_init_apic_ldr,
54 .ioapic_phys_id_map = default_ioapic_phys_id_map,
55 .cpu_present_to_apicid = default_cpu_present_to_apicid,
56 .phys_pkg_id = default_phys_pkg_id,
57
58 .max_apic_id = 0xFE,
59 .get_apic_id = default_get_apic_id,
60
61 .calc_dest_apicid = apic_flat_calc_apicid,
62
63 .send_IPI = default_send_IPI_single,
64 .send_IPI_mask = default_send_IPI_mask_logical,
65 .send_IPI_mask_allbutself = default_send_IPI_mask_allbutself_logical,
66 .send_IPI_allbutself = default_send_IPI_allbutself,
67 .send_IPI_all = default_send_IPI_all,
68 .send_IPI_self = default_send_IPI_self,
69
70 .read = native_apic_mem_read,
71 .write = native_apic_mem_write,
72 .eoi = native_apic_mem_eoi,
73 .icr_read = native_apic_icr_read,
74 .icr_write = native_apic_icr_write,
75 .wait_icr_idle = apic_mem_wait_icr_idle,
76 .safe_wait_icr_idle = apic_mem_wait_icr_idle_timeout,
77};
78
79apic_driver(apic_default);
80
81struct apic *apic __ro_after_init = &apic_default;
82EXPORT_SYMBOL_GPL(apic);
83
84static int cmdline_apic __initdata;
85static int __init parse_apic(char *arg)
86{
87 struct apic **drv;
88
89 if (!arg)
90 return -EINVAL;
91
92 for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
93 if (!strcmp((*drv)->name, arg)) {
94 apic_install_driver(*drv);
95 cmdline_apic = 1;
96 return 0;
97 }
98 }
99
100 /* Parsed again by __setup for debug/verbose */
101 return 0;
102}
103early_param("apic", parse_apic);
104
105void __init x86_32_probe_bigsmp_early(void)
106{
107 if (nr_cpu_ids <= 8 || xen_pv_domain())
108 return;
109
110 if (IS_ENABLED(CONFIG_X86_BIGSMP)) {
111 switch (boot_cpu_data.x86_vendor) {
112 case X86_VENDOR_INTEL:
113 if (!APIC_XAPIC(boot_cpu_apic_version))
114 break;
115 /* P4 and above */
116 fallthrough;
117 case X86_VENDOR_HYGON:
118 case X86_VENDOR_AMD:
119 if (apic_bigsmp_possible(cmdline_apic))
120 return;
121 break;
122 }
123 }
124 pr_info("Limiting to 8 possible CPUs\n");
125 set_nr_cpu_ids(8);
126}
127
128void __init x86_32_install_bigsmp(void)
129{
130 if (nr_cpu_ids > 8 && !xen_pv_domain())
131 apic_bigsmp_force();
132}
133
134void __init x86_32_probe_apic(void)
135{
136 if (!cmdline_apic) {
137 struct apic **drv;
138
139 for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
140 if ((*drv)->probe()) {
141 apic_install_driver(*drv);
142 break;
143 }
144 }
145 /* Not visible without early console */
146 if (drv == __apicdrivers_end)
147 panic("Didn't find an APIC driver");
148 }
149}