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