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 18 static int default_x86_32_early_logical_apicid(int cpu) 19 { 20 return 1 << cpu; 21 } 22 23 static 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 32 static 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 */ 42 static 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 52 static 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. */ 58 static int probe_default(void) 59 { 60 return 1; 61 } 62 63 static 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 }; 112 113 apic_driver(apic_default); 114 115 struct apic *apic __ro_after_init = &apic_default; 116 EXPORT_SYMBOL_GPL(apic); 117 118 static int cmdline_apic __initdata; 119 static 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 } 137 early_param("apic", parse_apic); 138 139 void __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 } 176 177 void __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() */ 196 int __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 } 215