aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/include/asm/ipi.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/include/asm/ipi.h')
-rw-r--r--arch/x86/include/asm/ipi.h138
1 files changed, 138 insertions, 0 deletions
diff --git a/arch/x86/include/asm/ipi.h b/arch/x86/include/asm/ipi.h
new file mode 100644
index 000000000000..f89dffb28aa9
--- /dev/null
+++ b/arch/x86/include/asm/ipi.h
@@ -0,0 +1,138 @@
1#ifndef _ASM_X86_IPI_H
2#define _ASM_X86_IPI_H
3
4/*
5 * Copyright 2004 James Cleverdon, IBM.
6 * Subject to the GNU Public License, v.2
7 *
8 * Generic APIC InterProcessor Interrupt code.
9 *
10 * Moved to include file by James Cleverdon from
11 * arch/x86-64/kernel/smp.c
12 *
13 * Copyrights from kernel/smp.c:
14 *
15 * (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
16 * (c) 1998-99, 2000 Ingo Molnar <mingo@redhat.com>
17 * (c) 2002,2003 Andi Kleen, SuSE Labs.
18 * Subject to the GNU Public License, v.2
19 */
20
21#include <asm/hw_irq.h>
22#include <asm/apic.h>
23#include <asm/smp.h>
24
25/*
26 * the following functions deal with sending IPIs between CPUs.
27 *
28 * We use 'broadcast', CPU->CPU IPIs and self-IPIs too.
29 */
30
31static inline unsigned int __prepare_ICR(unsigned int shortcut, int vector,
32 unsigned int dest)
33{
34 unsigned int icr = shortcut | dest;
35
36 switch (vector) {
37 default:
38 icr |= APIC_DM_FIXED | vector;
39 break;
40 case NMI_VECTOR:
41 icr |= APIC_DM_NMI;
42 break;
43 }
44 return icr;
45}
46
47static inline int __prepare_ICR2(unsigned int mask)
48{
49 return SET_APIC_DEST_FIELD(mask);
50}
51
52static inline void __xapic_wait_icr_idle(void)
53{
54 while (native_apic_mem_read(APIC_ICR) & APIC_ICR_BUSY)
55 cpu_relax();
56}
57
58static inline void __send_IPI_shortcut(unsigned int shortcut, int vector,
59 unsigned int dest)
60{
61 /*
62 * Subtle. In the case of the 'never do double writes' workaround
63 * we have to lock out interrupts to be safe. As we don't care
64 * of the value read we use an atomic rmw access to avoid costly
65 * cli/sti. Otherwise we use an even cheaper single atomic write
66 * to the APIC.
67 */
68 unsigned int cfg;
69
70 /*
71 * Wait for idle.
72 */
73 __xapic_wait_icr_idle();
74
75 /*
76 * No need to touch the target chip field
77 */
78 cfg = __prepare_ICR(shortcut, vector, dest);
79
80 /*
81 * Send the IPI. The write to APIC_ICR fires this off.
82 */
83 native_apic_mem_write(APIC_ICR, cfg);
84}
85
86/*
87 * This is used to send an IPI with no shorthand notation (the destination is
88 * specified in bits 56 to 63 of the ICR).
89 */
90static inline void __send_IPI_dest_field(unsigned int mask, int vector,
91 unsigned int dest)
92{
93 unsigned long cfg;
94
95 /*
96 * Wait for idle.
97 */
98 if (unlikely(vector == NMI_VECTOR))
99 safe_apic_wait_icr_idle();
100 else
101 __xapic_wait_icr_idle();
102
103 /*
104 * prepare target chip field
105 */
106 cfg = __prepare_ICR2(mask);
107 native_apic_mem_write(APIC_ICR2, cfg);
108
109 /*
110 * program the ICR
111 */
112 cfg = __prepare_ICR(0, vector, dest);
113
114 /*
115 * Send the IPI. The write to APIC_ICR fires this off.
116 */
117 native_apic_mem_write(APIC_ICR, cfg);
118}
119
120static inline void send_IPI_mask_sequence(cpumask_t mask, int vector)
121{
122 unsigned long flags;
123 unsigned long query_cpu;
124
125 /*
126 * Hack. The clustered APIC addressing mode doesn't allow us to send
127 * to an arbitrary mask, so I do a unicast to each CPU instead.
128 * - mbligh
129 */
130 local_irq_save(flags);
131 for_each_cpu_mask_nr(query_cpu, mask) {
132 __send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, query_cpu),
133 vector, APIC_DEST_PHYSICAL);
134 }
135 local_irq_restore(flags);
136}
137
138#endif /* _ASM_X86_IPI_H */