1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <linux/cpumask.h> 4 #include <linux/smp.h> 5 6 #include "local.h" 7 8 static inline int __prepare_ICR2(unsigned int mask) 9 { 10 return SET_APIC_DEST_FIELD(mask); 11 } 12 13 static inline void __xapic_wait_icr_idle(void) 14 { 15 while (native_apic_mem_read(APIC_ICR) & APIC_ICR_BUSY) 16 cpu_relax(); 17 } 18 19 void __default_send_IPI_shortcut(unsigned int shortcut, int vector) 20 { 21 /* 22 * Subtle. In the case of the 'never do double writes' workaround 23 * we have to lock out interrupts to be safe. As we don't care 24 * of the value read we use an atomic rmw access to avoid costly 25 * cli/sti. Otherwise we use an even cheaper single atomic write 26 * to the APIC. 27 */ 28 unsigned int cfg; 29 30 /* 31 * Wait for idle. 32 */ 33 if (unlikely(vector == NMI_VECTOR)) 34 safe_apic_wait_icr_idle(); 35 else 36 __xapic_wait_icr_idle(); 37 38 /* 39 * No need to touch the target chip field. Also the destination 40 * mode is ignored when a shorthand is used. 41 */ 42 cfg = __prepare_ICR(shortcut, vector, 0); 43 44 /* 45 * Send the IPI. The write to APIC_ICR fires this off. 46 */ 47 native_apic_mem_write(APIC_ICR, cfg); 48 } 49 50 /* 51 * This is used to send an IPI with no shorthand notation (the destination is 52 * specified in bits 56 to 63 of the ICR). 53 */ 54 void __default_send_IPI_dest_field(unsigned int mask, int vector, unsigned int dest) 55 { 56 unsigned long cfg; 57 58 /* 59 * Wait for idle. 60 */ 61 if (unlikely(vector == NMI_VECTOR)) 62 safe_apic_wait_icr_idle(); 63 else 64 __xapic_wait_icr_idle(); 65 66 /* 67 * prepare target chip field 68 */ 69 cfg = __prepare_ICR2(mask); 70 native_apic_mem_write(APIC_ICR2, cfg); 71 72 /* 73 * program the ICR 74 */ 75 cfg = __prepare_ICR(0, vector, dest); 76 77 /* 78 * Send the IPI. The write to APIC_ICR fires this off. 79 */ 80 native_apic_mem_write(APIC_ICR, cfg); 81 } 82 83 void default_send_IPI_single_phys(int cpu, int vector) 84 { 85 unsigned long flags; 86 87 local_irq_save(flags); 88 __default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, cpu), 89 vector, APIC_DEST_PHYSICAL); 90 local_irq_restore(flags); 91 } 92 93 void default_send_IPI_mask_sequence_phys(const struct cpumask *mask, int vector) 94 { 95 unsigned long query_cpu; 96 unsigned long flags; 97 98 /* 99 * Hack. The clustered APIC addressing mode doesn't allow us to send 100 * to an arbitrary mask, so I do a unicast to each CPU instead. 101 * - mbligh 102 */ 103 local_irq_save(flags); 104 for_each_cpu(query_cpu, mask) { 105 __default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, 106 query_cpu), vector, APIC_DEST_PHYSICAL); 107 } 108 local_irq_restore(flags); 109 } 110 111 void default_send_IPI_mask_allbutself_phys(const struct cpumask *mask, 112 int vector) 113 { 114 unsigned int this_cpu = smp_processor_id(); 115 unsigned int query_cpu; 116 unsigned long flags; 117 118 /* See Hack comment above */ 119 120 local_irq_save(flags); 121 for_each_cpu(query_cpu, mask) { 122 if (query_cpu == this_cpu) 123 continue; 124 __default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, 125 query_cpu), vector, APIC_DEST_PHYSICAL); 126 } 127 local_irq_restore(flags); 128 } 129 130 /* 131 * Helper function for APICs which insist on cpumasks 132 */ 133 void default_send_IPI_single(int cpu, int vector) 134 { 135 apic->send_IPI_mask(cpumask_of(cpu), vector); 136 } 137 138 #ifdef CONFIG_X86_32 139 140 void default_send_IPI_mask_sequence_logical(const struct cpumask *mask, 141 int vector) 142 { 143 unsigned long flags; 144 unsigned int query_cpu; 145 146 /* 147 * Hack. The clustered APIC addressing mode doesn't allow us to send 148 * to an arbitrary mask, so I do a unicasts to each CPU instead. This 149 * should be modified to do 1 message per cluster ID - mbligh 150 */ 151 152 local_irq_save(flags); 153 for_each_cpu(query_cpu, mask) 154 __default_send_IPI_dest_field( 155 early_per_cpu(x86_cpu_to_logical_apicid, query_cpu), 156 vector, apic->dest_logical); 157 local_irq_restore(flags); 158 } 159 160 void default_send_IPI_mask_allbutself_logical(const struct cpumask *mask, 161 int vector) 162 { 163 unsigned long flags; 164 unsigned int query_cpu; 165 unsigned int this_cpu = smp_processor_id(); 166 167 /* See Hack comment above */ 168 169 local_irq_save(flags); 170 for_each_cpu(query_cpu, mask) { 171 if (query_cpu == this_cpu) 172 continue; 173 __default_send_IPI_dest_field( 174 early_per_cpu(x86_cpu_to_logical_apicid, query_cpu), 175 vector, apic->dest_logical); 176 } 177 local_irq_restore(flags); 178 } 179 180 /* 181 * This is only used on smaller machines. 182 */ 183 void default_send_IPI_mask_logical(const struct cpumask *cpumask, int vector) 184 { 185 unsigned long mask = cpumask_bits(cpumask)[0]; 186 unsigned long flags; 187 188 if (!mask) 189 return; 190 191 local_irq_save(flags); 192 WARN_ON(mask & ~cpumask_bits(cpu_online_mask)[0]); 193 __default_send_IPI_dest_field(mask, vector, apic->dest_logical); 194 local_irq_restore(flags); 195 } 196 197 void default_send_IPI_allbutself(int vector) 198 { 199 /* 200 * if there are no other CPUs in the system then we get an APIC send 201 * error if we try to broadcast, thus avoid sending IPIs in this case. 202 */ 203 if (num_online_cpus() < 2) 204 return; 205 206 if (no_broadcast || vector == NMI_VECTOR) { 207 apic->send_IPI_mask_allbutself(cpu_online_mask, vector); 208 } else { 209 __default_send_IPI_shortcut(APIC_DEST_ALLBUT, vector); 210 } 211 } 212 213 void default_send_IPI_all(int vector) 214 { 215 if (no_broadcast || vector == NMI_VECTOR) { 216 apic->send_IPI_mask(cpu_online_mask, vector); 217 } else { 218 __default_send_IPI_shortcut(APIC_DEST_ALLINC, vector); 219 } 220 } 221 222 void default_send_IPI_self(int vector) 223 { 224 __default_send_IPI_shortcut(APIC_DEST_SELF, vector); 225 } 226 227 /* must come after the send_IPI functions above for inlining */ 228 static int convert_apicid_to_cpu(int apic_id) 229 { 230 int i; 231 232 for_each_possible_cpu(i) { 233 if (per_cpu(x86_cpu_to_apicid, i) == apic_id) 234 return i; 235 } 236 return -1; 237 } 238 239 int safe_smp_processor_id(void) 240 { 241 int apicid, cpuid; 242 243 if (!boot_cpu_has(X86_FEATURE_APIC)) 244 return 0; 245 246 apicid = hard_smp_processor_id(); 247 if (apicid == BAD_APICID) 248 return 0; 249 250 cpuid = convert_apicid_to_cpu(apicid); 251 252 return cpuid >= 0 ? cpuid : 0; 253 } 254 #endif 255