1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2004 James Cleverdon, IBM. 4 * 5 * Flat APIC subarch code. 6 * 7 * Hacked for x86-64 by James Cleverdon from i386 architecture code by 8 * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and 9 * James Cleverdon. 10 */ 11 #include <linux/cpumask.h> 12 #include <linux/export.h> 13 #include <linux/acpi.h> 14 15 #include <asm/jailhouse_para.h> 16 #include <asm/apic.h> 17 18 #include "local.h" 19 20 static struct apic apic_physflat; 21 static struct apic apic_flat; 22 23 struct apic *apic __ro_after_init = &apic_flat; 24 EXPORT_SYMBOL_GPL(apic); 25 26 static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id) 27 { 28 return 1; 29 } 30 31 /* 32 * Set up the logical destination ID. 33 * 34 * Intel recommends to set DFR, LDR and TPR before enabling 35 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel 36 * document number 292116). So here it goes... 37 */ 38 void flat_init_apic_ldr(void) 39 { 40 unsigned long val; 41 unsigned long num, id; 42 43 num = smp_processor_id(); 44 id = 1UL << num; 45 apic_write(APIC_DFR, APIC_DFR_FLAT); 46 val = apic_read(APIC_LDR) & ~APIC_LDR_MASK; 47 val |= SET_APIC_LOGICAL_ID(id); 48 apic_write(APIC_LDR, val); 49 } 50 51 static void _flat_send_IPI_mask(unsigned long mask, int vector) 52 { 53 unsigned long flags; 54 55 local_irq_save(flags); 56 __default_send_IPI_dest_field(mask, vector, APIC_DEST_LOGICAL); 57 local_irq_restore(flags); 58 } 59 60 static void flat_send_IPI_mask(const struct cpumask *cpumask, int vector) 61 { 62 unsigned long mask = cpumask_bits(cpumask)[0]; 63 64 _flat_send_IPI_mask(mask, vector); 65 } 66 67 static void 68 flat_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) 69 { 70 unsigned long mask = cpumask_bits(cpumask)[0]; 71 int cpu = smp_processor_id(); 72 73 if (cpu < BITS_PER_LONG) 74 __clear_bit(cpu, &mask); 75 76 _flat_send_IPI_mask(mask, vector); 77 } 78 79 static unsigned int flat_get_apic_id(unsigned long x) 80 { 81 return (x >> 24) & 0xFF; 82 } 83 84 static u32 set_apic_id(unsigned int id) 85 { 86 return (id & 0xFF) << 24; 87 } 88 89 static unsigned int read_xapic_id(void) 90 { 91 return flat_get_apic_id(apic_read(APIC_ID)); 92 } 93 94 static int flat_apic_id_registered(void) 95 { 96 return physid_isset(read_xapic_id(), phys_cpu_present_map); 97 } 98 99 static int flat_phys_pkg_id(int initial_apic_id, int index_msb) 100 { 101 return initial_apic_id >> index_msb; 102 } 103 104 static int flat_probe(void) 105 { 106 return 1; 107 } 108 109 static struct apic apic_flat __ro_after_init = { 110 .name = "flat", 111 .probe = flat_probe, 112 .acpi_madt_oem_check = flat_acpi_madt_oem_check, 113 .apic_id_valid = default_apic_id_valid, 114 .apic_id_registered = flat_apic_id_registered, 115 116 .delivery_mode = APIC_DELIVERY_MODE_FIXED, 117 .dest_mode_logical = true, 118 119 .disable_esr = 0, 120 121 .check_apicid_used = NULL, 122 .init_apic_ldr = flat_init_apic_ldr, 123 .ioapic_phys_id_map = NULL, 124 .setup_apic_routing = NULL, 125 .cpu_present_to_apicid = default_cpu_present_to_apicid, 126 .apicid_to_cpu_present = NULL, 127 .check_phys_apicid_present = default_check_phys_apicid_present, 128 .phys_pkg_id = flat_phys_pkg_id, 129 130 .get_apic_id = flat_get_apic_id, 131 .set_apic_id = set_apic_id, 132 133 .calc_dest_apicid = apic_flat_calc_apicid, 134 135 .send_IPI = default_send_IPI_single, 136 .send_IPI_mask = flat_send_IPI_mask, 137 .send_IPI_mask_allbutself = flat_send_IPI_mask_allbutself, 138 .send_IPI_allbutself = default_send_IPI_allbutself, 139 .send_IPI_all = default_send_IPI_all, 140 .send_IPI_self = default_send_IPI_self, 141 142 .inquire_remote_apic = default_inquire_remote_apic, 143 144 .read = native_apic_mem_read, 145 .write = native_apic_mem_write, 146 .eoi_write = native_apic_mem_write, 147 .icr_read = native_apic_icr_read, 148 .icr_write = native_apic_icr_write, 149 .wait_icr_idle = native_apic_wait_icr_idle, 150 .safe_wait_icr_idle = native_safe_apic_wait_icr_idle, 151 }; 152 153 /* 154 * Physflat mode is used when there are more than 8 CPUs on a system. 155 * We cannot use logical delivery in this case because the mask 156 * overflows, so use physical mode. 157 */ 158 static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id) 159 { 160 #ifdef CONFIG_ACPI 161 /* 162 * Quirk: some x86_64 machines can only use physical APIC mode 163 * regardless of how many processors are present (x86_64 ES7000 164 * is an example). 165 */ 166 if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && 167 (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) { 168 printk(KERN_DEBUG "system APIC only can use physical flat"); 169 return 1; 170 } 171 172 if (!strncmp(oem_id, "IBM", 3) && !strncmp(oem_table_id, "EXA", 3)) { 173 printk(KERN_DEBUG "IBM Summit detected, will use apic physical"); 174 return 1; 175 } 176 #endif 177 178 return 0; 179 } 180 181 static void physflat_init_apic_ldr(void) 182 { 183 /* 184 * LDR and DFR are not involved in physflat mode, rather: 185 * "In physical destination mode, the destination processor is 186 * specified by its local APIC ID [...]." (Intel SDM, 10.6.2.1) 187 */ 188 } 189 190 static int physflat_probe(void) 191 { 192 if (apic == &apic_physflat || num_possible_cpus() > 8 || 193 jailhouse_paravirt()) 194 return 1; 195 196 return 0; 197 } 198 199 static struct apic apic_physflat __ro_after_init = { 200 201 .name = "physical flat", 202 .probe = physflat_probe, 203 .acpi_madt_oem_check = physflat_acpi_madt_oem_check, 204 .apic_id_valid = default_apic_id_valid, 205 .apic_id_registered = flat_apic_id_registered, 206 207 .delivery_mode = APIC_DELIVERY_MODE_FIXED, 208 .dest_mode_logical = false, 209 210 .disable_esr = 0, 211 212 .check_apicid_used = NULL, 213 .init_apic_ldr = physflat_init_apic_ldr, 214 .ioapic_phys_id_map = NULL, 215 .setup_apic_routing = NULL, 216 .cpu_present_to_apicid = default_cpu_present_to_apicid, 217 .apicid_to_cpu_present = NULL, 218 .check_phys_apicid_present = default_check_phys_apicid_present, 219 .phys_pkg_id = flat_phys_pkg_id, 220 221 .get_apic_id = flat_get_apic_id, 222 .set_apic_id = set_apic_id, 223 224 .calc_dest_apicid = apic_default_calc_apicid, 225 226 .send_IPI = default_send_IPI_single_phys, 227 .send_IPI_mask = default_send_IPI_mask_sequence_phys, 228 .send_IPI_mask_allbutself = default_send_IPI_mask_allbutself_phys, 229 .send_IPI_allbutself = default_send_IPI_allbutself, 230 .send_IPI_all = default_send_IPI_all, 231 .send_IPI_self = default_send_IPI_self, 232 233 .inquire_remote_apic = default_inquire_remote_apic, 234 235 .read = native_apic_mem_read, 236 .write = native_apic_mem_write, 237 .eoi_write = native_apic_mem_write, 238 .icr_read = native_apic_icr_read, 239 .icr_write = native_apic_icr_write, 240 .wait_icr_idle = native_apic_wait_icr_idle, 241 .safe_wait_icr_idle = native_safe_apic_wait_icr_idle, 242 }; 243 244 /* 245 * We need to check for physflat first, so this order is important. 246 */ 247 apic_drivers(apic_physflat, apic_flat); 248