arch/x86/kernel/apic/apic_common.c

   1 /*
   2  * Common functions shared between the various APIC flavours
   3  *
   4  * SPDX-License-Identifier: GPL-2.0
   5  */
   6 #include <linux/irq.h>
   7 #include <asm/apic.h>
   8
   9 #include "local.h"
  10
  11 u32 apic_default_calc_apicid(unsigned int cpu)
  12 {
  13         return per_cpu(x86_cpu_to_apicid, cpu);
  14 }
  15
  16 u32 apic_flat_calc_apicid(unsigned int cpu)
  17 {
  18         return 1U << cpu;
  19 }
  20
  21 u32 default_cpu_present_to_apicid(int mps_cpu)
  22 {
  23         if (mps_cpu < nr_cpu_ids && cpu_present(mps_cpu))
  24                 return (int)per_cpu(x86_cpu_to_apicid, mps_cpu);
  25         else
  26                 return BAD_APICID;
  27 }
  28 EXPORT_SYMBOL_GPL(default_cpu_present_to_apicid);
  29
  30 /*
  31  * Set up the logical destination ID when the APIC operates in logical
  32  * destination mode.
  33  */
  34 void default_init_apic_ldr(void)
  35 {
  36         unsigned long val;
  37
  38         apic_write(APIC_DFR, APIC_DFR_FLAT);
  39         val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
  40         val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
  41         apic_write(APIC_LDR, val);
  42 }