1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/cpumask.h> 3 #include <linux/interrupt.h> 4 5 #include <linux/mm.h> 6 #include <linux/delay.h> 7 #include <linux/spinlock.h> 8 #include <linux/kernel_stat.h> 9 #include <linux/mc146818rtc.h> 10 #include <linux/cache.h> 11 #include <linux/cpu.h> 12 13 #include <asm/smp.h> 14 #include <asm/mtrr.h> 15 #include <asm/tlbflush.h> 16 #include <asm/mmu_context.h> 17 #include <asm/apic.h> 18 #include <asm/proto.h> 19 #include <asm/ipi.h> 20 21 void __default_send_IPI_shortcut(unsigned int shortcut, int vector, unsigned int dest) 22 { 23 /* 24 * Subtle. In the case of the 'never do double writes' workaround 25 * we have to lock out interrupts to be safe. As we don't care 26 * of the value read we use an atomic rmw access to avoid costly 27 * cli/sti. Otherwise we use an even cheaper single atomic write 28 * to the APIC. 29 */ 30 unsigned int cfg; 31 32 /* 33 * Wait for idle. 34 */ 35 __xapic_wait_icr_idle(); 36 37 /* 38 * No need to touch the target chip field 39 */ 40 cfg = __prepare_ICR(shortcut, vector, dest); 41 42 /* 43 * Send the IPI. The write to APIC_ICR fires this off. 44 */ 45 native_apic_mem_write(APIC_ICR, cfg); 46 } 47 48 /* 49 * This is used to send an IPI with no shorthand notation (the destination is 50 * specified in bits 56 to 63 of the ICR). 51 */ 52 void __default_send_IPI_dest_field(unsigned int mask, int vector, unsigned int dest) 53 { 54 unsigned long cfg; 55 56 /* 57 * Wait for idle. 58 */ 59 if (unlikely(vector == NMI_VECTOR)) 60 safe_apic_wait_icr_idle(); 61 else 62 __xapic_wait_icr_idle(); 63 64 /* 65 * prepare target chip field 66 */ 67 cfg = __prepare_ICR2(mask); 68 native_apic_mem_write(APIC_ICR2, cfg); 69 70 /* 71 * program the ICR 72 */ 73 cfg = __prepare_ICR(0, vector, dest); 74 75 /* 76 * Send the IPI. The write to APIC_ICR fires this off. 77 */ 78 native_apic_mem_write(APIC_ICR, cfg); 79 } 80 81 void default_send_IPI_single_phys(int cpu, int vector) 82 { 83 unsigned long flags; 84 85 local_irq_save(flags); 86 __default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, cpu), 87 vector, APIC_DEST_PHYSICAL); 88 local_irq_restore(flags); 89 } 90 91 void default_send_IPI_mask_sequence_phys(const struct cpumask *mask, int vector) 92 { 93 unsigned long query_cpu; 94 unsigned long flags; 95 96 /* 97 * Hack. The clustered APIC addressing mode doesn't allow us to send 98 * to an arbitrary mask, so I do a unicast to each CPU instead. 99 * - mbligh 100 */ 101 local_irq_save(flags); 102 for_each_cpu(query_cpu, mask) { 103 __default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, 104 query_cpu), vector, APIC_DEST_PHYSICAL); 105 } 106 local_irq_restore(flags); 107 } 108 109 void default_send_IPI_mask_allbutself_phys(const struct cpumask *mask, 110 int vector) 111 { 112 unsigned int this_cpu = smp_processor_id(); 113 unsigned int query_cpu; 114 unsigned long flags; 115 116 /* See Hack comment above */ 117 118 local_irq_save(flags); 119 for_each_cpu(query_cpu, mask) { 120 if (query_cpu == this_cpu) 121 continue; 122 __default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, 123 query_cpu), vector, APIC_DEST_PHYSICAL); 124 } 125 local_irq_restore(flags); 126 } 127 128 /* 129 * Helper function for APICs which insist on cpumasks 130 */ 131 void default_send_IPI_single(int cpu, int vector) 132 { 133 apic->send_IPI_mask(cpumask_of(cpu), vector); 134 } 135 136 #ifdef CONFIG_X86_32 137 138 void default_send_IPI_mask_sequence_logical(const struct cpumask *mask, 139 int vector) 140 { 141 unsigned long flags; 142 unsigned int query_cpu; 143 144 /* 145 * Hack. The clustered APIC addressing mode doesn't allow us to send 146 * to an arbitrary mask, so I do a unicasts to each CPU instead. This 147 * should be modified to do 1 message per cluster ID - mbligh 148 */ 149 150 local_irq_save(flags); 151 for_each_cpu(query_cpu, mask) 152 __default_send_IPI_dest_field( 153 early_per_cpu(x86_cpu_to_logical_apicid, query_cpu), 154 vector, apic->dest_logical); 155 local_irq_restore(flags); 156 } 157 158 void default_send_IPI_mask_allbutself_logical(const struct cpumask *mask, 159 int vector) 160 { 161 unsigned long flags; 162 unsigned int query_cpu; 163 unsigned int this_cpu = smp_processor_id(); 164 165 /* See Hack comment above */ 166 167 local_irq_save(flags); 168 for_each_cpu(query_cpu, mask) { 169 if (query_cpu == this_cpu) 170 continue; 171 __default_send_IPI_dest_field( 172 early_per_cpu(x86_cpu_to_logical_apicid, query_cpu), 173 vector, apic->dest_logical); 174 } 175 local_irq_restore(flags); 176 } 177 178 /* 179 * This is only used on smaller machines. 180 */ 181 void default_send_IPI_mask_logical(const struct cpumask *cpumask, int vector) 182 { 183 unsigned long mask = cpumask_bits(cpumask)[0]; 184 unsigned long flags; 185 186 if (!mask) 187 return; 188 189 local_irq_save(flags); 190 WARN_ON(mask & ~cpumask_bits(cpu_online_mask)[0]); 191 __default_send_IPI_dest_field(mask, vector, apic->dest_logical); 192 local_irq_restore(flags); 193 } 194 195 void default_send_IPI_allbutself(int vector) 196 { 197 /* 198 * if there are no other CPUs in the system then we get an APIC send 199 * error if we try to broadcast, thus avoid sending IPIs in this case. 200 */ 201 if (!(num_online_cpus() > 1)) 202 return; 203 204 __default_local_send_IPI_allbutself(vector); 205 } 206 207 void default_send_IPI_all(int vector) 208 { 209 __default_local_send_IPI_all(vector); 210 } 211 212 void default_send_IPI_self(int vector) 213 { 214 __default_send_IPI_shortcut(APIC_DEST_SELF, vector, apic->dest_logical); 215 } 216 217 /* must come after the send_IPI functions above for inlining */ 218 static int convert_apicid_to_cpu(int apic_id) 219 { 220 int i; 221 222 for_each_possible_cpu(i) { 223 if (per_cpu(x86_cpu_to_apicid, i) == apic_id) 224 return i; 225 } 226 return -1; 227 } 228 229 int safe_smp_processor_id(void) 230 { 231 int apicid, cpuid; 232 233 if (!boot_cpu_has(X86_FEATURE_APIC)) 234 return 0; 235 236 apicid = hard_smp_processor_id(); 237 if (apicid == BAD_APICID) 238 return 0; 239 240 cpuid = convert_apicid_to_cpu(apicid); 241 242 return cpuid >= 0 ? cpuid : 0; 243 } 244 #endif 245