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
default_phys_pkg_id(u32 cpuid_apic,int index_msb)21 static u32 default_phys_pkg_id(u32 cpuid_apic, int index_msb)
22 {
23 return cpuid_apic >> index_msb;
24 }
25
default_get_apic_id(u32 x)26 static 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. */
probe_default(void)37 static int probe_default(void)
38 {
39 return 1;
40 }
41
42 static 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
79 apic_driver(apic_default);
80
81 struct apic *apic __ro_after_init = &apic_default;
82 EXPORT_SYMBOL_GPL(apic);
83
84 static int cmdline_apic __initdata;
parse_apic(char * arg)85 static 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 }
103 early_param("apic", parse_apic);
104
x86_32_probe_bigsmp_early(void)105 void __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
x86_32_install_bigsmp(void)128 void __init x86_32_install_bigsmp(void)
129 {
130 if (nr_cpu_ids > 8 && !xen_pv_domain())
131 apic_bigsmp_force();
132 }
133
x86_32_probe_apic(void)134 void __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 }
150