xref: /linux/arch/x86/kernel/apic/apic_common.c (revision 4a5f72a4)
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 
apic_default_calc_apicid(unsigned int cpu)11 u32 apic_default_calc_apicid(unsigned int cpu)
12 {
13 	return per_cpu(x86_cpu_to_apicid, cpu);
14 }
15 
apic_flat_calc_apicid(unsigned int cpu)16 u32 apic_flat_calc_apicid(unsigned int cpu)
17 {
18 	return 1U << cpu;
19 }
20 
default_cpu_present_to_apicid(int mps_cpu)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  */
default_init_apic_ldr(void)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 }
43