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1/*
2 * Copyright 2004 James Cleverdon, IBM.
3 * Subject to the GNU Public License, v.2
4 *
5 * Clustered APIC subarch code. Up to 255 CPUs, physical delivery.
6 * (A more realistic maximum is around 230 CPUs.)
7 *
8 * Hacked for x86-64 by James Cleverdon from i386 architecture code by
9 * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
10 * James Cleverdon.
11 */
12#include <linux/config.h>
13#include <linux/threads.h>
14#include <linux/cpumask.h>
15#include <linux/string.h>
16#include <linux/kernel.h>
17#include <linux/ctype.h>
18#include <linux/init.h>
19#include <asm/smp.h>
20#include <asm/ipi.h>
21
22
23/*
24 * Set up the logical destination ID.
25 *
26 * Intel recommends to set DFR, LDR and TPR before enabling
27 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
28 * document number 292116). So here it goes...
29 */
30static void cluster_init_apic_ldr(void)
31{
32 unsigned long val, id;
33 long i, count;
34 u8 lid;
35 u8 my_id = hard_smp_processor_id();
36 u8 my_cluster = APIC_CLUSTER(my_id);
37
38 /* Create logical APIC IDs by counting CPUs already in cluster. */
39 for (count = 0, i = NR_CPUS; --i >= 0; ) {
40 lid = x86_cpu_to_log_apicid[i];
41 if (lid != BAD_APICID && APIC_CLUSTER(lid) == my_cluster)
42 ++count;
43 }
44 /*
45 * We only have a 4 wide bitmap in cluster mode. There's no way
46 * to get above 60 CPUs and still give each one it's own bit.
47 * But, we're using physical IRQ delivery, so we don't care.
48 * Use bit 3 for the 4th through Nth CPU in each cluster.
49 */
50 if (count >= XAPIC_DEST_CPUS_SHIFT)
51 count = 3;
52 id = my_cluster | (1UL << count);
53 x86_cpu_to_log_apicid[smp_processor_id()] = id;
54 apic_write_around(APIC_DFR, APIC_DFR_CLUSTER);
55 val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
56 val |= SET_APIC_LOGICAL_ID(id);
57 apic_write_around(APIC_LDR, val);
58}
59
60/* Start with all IRQs pointing to boot CPU. IRQ balancing will shift them. */
61
62static cpumask_t cluster_target_cpus(void)
63{
64 return cpumask_of_cpu(0);
65}
66
67static void cluster_send_IPI_mask(cpumask_t mask, int vector)
68{
69 send_IPI_mask_sequence(mask, vector);
70}
71
72static void cluster_send_IPI_allbutself(int vector)
73{
74 cpumask_t mask = cpu_online_map;
75 cpu_clear(smp_processor_id(), mask);
76
77 if (!cpus_empty(mask))
78 cluster_send_IPI_mask(mask, vector);
79}
80
81static void cluster_send_IPI_all(int vector)
82{
83 cluster_send_IPI_mask(cpu_online_map, vector);
84}
85
86static int cluster_apic_id_registered(void)
87{
88 return 1;
89}
90
91static unsigned int cluster_cpu_mask_to_apicid(cpumask_t cpumask)
92{
93 int cpu;
94
95 /*
96 * We're using fixed IRQ delivery, can only return one phys APIC ID.
97 * May as well be the first.
98 */
99 cpu = first_cpu(cpumask);
100 if ((unsigned)cpu < NR_CPUS)
101 return x86_cpu_to_apicid[cpu];
102 else
103 return BAD_APICID;
104}
105
106/* cpuid returns the value latched in the HW at reset, not the APIC ID
107 * register's value. For any box whose BIOS changes APIC IDs, like
108 * clustered APIC systems, we must use hard_smp_processor_id.
109 *
110 * See Intel's IA-32 SW Dev's Manual Vol2 under CPUID.
111 */
112static unsigned int phys_pkg_id(int index_msb)
113{
114 return hard_smp_processor_id() >> index_msb;
115}
116
117struct genapic apic_cluster = {
118 .name = "clustered",
119 .int_delivery_mode = dest_Fixed,
120 .int_dest_mode = (APIC_DEST_PHYSICAL != 0),
121 .int_delivery_dest = APIC_DEST_PHYSICAL | APIC_DM_FIXED,
122 .target_cpus = cluster_target_cpus,
123 .apic_id_registered = cluster_apic_id_registered,
124 .init_apic_ldr = cluster_init_apic_ldr,
125 .send_IPI_all = cluster_send_IPI_all,
126 .send_IPI_allbutself = cluster_send_IPI_allbutself,
127 .send_IPI_mask = cluster_send_IPI_mask,
128 .cpu_mask_to_apicid = cluster_cpu_mask_to_apicid,
129 .phys_pkg_id = phys_pkg_id,
130};