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 .irq_delivery_mode = dest_Fixed, 73 /* logical delivery broadcast to all CPUs: */ 74 .irq_dest_mode = 1, 75 76 .disable_esr = 0, 77 .dest_logical = APIC_DEST_LOGICAL, 78 .check_apicid_used = default_check_apicid_used, 79 80 .init_apic_ldr = default_init_apic_ldr, 81 82 .ioapic_phys_id_map = default_ioapic_phys_id_map, 83 .setup_apic_routing = setup_apic_flat_routing, 84 .cpu_present_to_apicid = default_cpu_present_to_apicid, 85 .apicid_to_cpu_present = physid_set_mask_of_physid, 86 .check_phys_apicid_present = default_check_phys_apicid_present, 87 .phys_pkg_id = default_phys_pkg_id, 88 89 .get_apic_id = default_get_apic_id, 90 .set_apic_id = NULL, 91 92 .calc_dest_apicid = apic_flat_calc_apicid, 93 94 .send_IPI = default_send_IPI_single, 95 .send_IPI_mask = default_send_IPI_mask_logical, 96 .send_IPI_mask_allbutself = default_send_IPI_mask_allbutself_logical, 97 .send_IPI_allbutself = default_send_IPI_allbutself, 98 .send_IPI_all = default_send_IPI_all, 99 .send_IPI_self = default_send_IPI_self, 100 101 .inquire_remote_apic = default_inquire_remote_apic, 102 103 .read = native_apic_mem_read, 104 .write = native_apic_mem_write, 105 .eoi_write = native_apic_mem_write, 106 .icr_read = native_apic_icr_read, 107 .icr_write = native_apic_icr_write, 108 .wait_icr_idle = native_apic_wait_icr_idle, 109 .safe_wait_icr_idle = native_safe_apic_wait_icr_idle, 110 111 .x86_32_early_logical_apicid = default_x86_32_early_logical_apicid, 112 }; 113 114 apic_driver(apic_default); 115 116 struct apic *apic __ro_after_init = &apic_default; 117 EXPORT_SYMBOL_GPL(apic); 118 119 static int cmdline_apic __initdata; 120 static int __init parse_apic(char *arg) 121 { 122 struct apic **drv; 123 124 if (!arg) 125 return -EINVAL; 126 127 for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) { 128 if (!strcmp((*drv)->name, arg)) { 129 apic = *drv; 130 cmdline_apic = 1; 131 return 0; 132 } 133 } 134 135 /* Parsed again by __setup for debug/verbose */ 136 return 0; 137 } 138 early_param("apic", parse_apic); 139 140 void __init default_setup_apic_routing(void) 141 { 142 int version = boot_cpu_apic_version; 143 144 if (num_possible_cpus() > 8) { 145 switch (boot_cpu_data.x86_vendor) { 146 case X86_VENDOR_INTEL: 147 if (!APIC_XAPIC(version)) { 148 def_to_bigsmp = 0; 149 break; 150 } 151 /* P4 and above */ 152 fallthrough; 153 case X86_VENDOR_HYGON: 154 case X86_VENDOR_AMD: 155 def_to_bigsmp = 1; 156 } 157 } 158 159 #ifdef CONFIG_X86_BIGSMP 160 /* 161 * This is used to switch to bigsmp mode when 162 * - There is no apic= option specified by the user 163 * - generic_apic_probe() has chosen apic_default as the sub_arch 164 * - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support 165 */ 166 167 if (!cmdline_apic && apic == &apic_default) 168 generic_bigsmp_probe(); 169 #endif 170 171 if (apic->setup_apic_routing) 172 apic->setup_apic_routing(); 173 } 174 175 void __init generic_apic_probe(void) 176 { 177 if (!cmdline_apic) { 178 struct apic **drv; 179 180 for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) { 181 if ((*drv)->probe()) { 182 apic = *drv; 183 break; 184 } 185 } 186 /* Not visible without early console */ 187 if (drv == __apicdrivers_end) 188 panic("Didn't find an APIC driver"); 189 } 190 printk(KERN_INFO "Using APIC driver %s\n", apic->name); 191 } 192 193 /* This function can switch the APIC even after the initial ->probe() */ 194 int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id) 195 { 196 struct apic **drv; 197 198 for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) { 199 if (!(*drv)->acpi_madt_oem_check) 200 continue; 201 if (!(*drv)->acpi_madt_oem_check(oem_id, oem_table_id)) 202 continue; 203 204 if (!cmdline_apic) { 205 apic = *drv; 206 printk(KERN_INFO "Switched to APIC driver `%s'.\n", 207 apic->name); 208 } 209 return 1; 210 } 211 return 0; 212 } 213