summaryrefslogtreecommitdiff
path: root/arch/x86_64/kernel/genapic_cluster.c
blob: 43fcf62fef0f5aa0931930b1881cc88f7b50605c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
/*
 * Copyright 2004 James Cleverdon, IBM.
 * Subject to the GNU Public License, v.2
 *
 * Clustered APIC subarch code.  Up to 255 CPUs, physical delivery.
 * (A more realistic maximum is around 230 CPUs.)
 *
 * Hacked for x86-64 by James Cleverdon from i386 architecture code by
 * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
 * James Cleverdon.
 */
#include <linux/config.h>
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <asm/smp.h>
#include <asm/ipi.h>


/*
 * Set up the logical destination ID.
 *
 * Intel recommends to set DFR, LDR and TPR before enabling
 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
 * document number 292116).  So here it goes...
 */
static void cluster_init_apic_ldr(void)
{
	unsigned long val, id;
	long i, count;
	u8 lid;
	u8 my_id = hard_smp_processor_id();
	u8 my_cluster = APIC_CLUSTER(my_id);

	/* Create logical APIC IDs by counting CPUs already in cluster. */
	for (count = 0, i = NR_CPUS; --i >= 0; ) {
		lid = x86_cpu_to_log_apicid[i];
		if (lid != BAD_APICID && APIC_CLUSTER(lid) == my_cluster)
			++count;
	}
	/*
	 * We only have a 4 wide bitmap in cluster mode.  There's no way
	 * to get above 60 CPUs and still give each one it's own bit.
	 * But, we're using physical IRQ delivery, so we don't care.
	 * Use bit 3 for the 4th through Nth CPU in each cluster.
	 */
	if (count >= XAPIC_DEST_CPUS_SHIFT)
		count = 3;
	id = my_cluster | (1UL << count);
	x86_cpu_to_log_apicid[smp_processor_id()] = id;
	apic_write(APIC_DFR, APIC_DFR_CLUSTER);
	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
	val |= SET_APIC_LOGICAL_ID(id);
	apic_write(APIC_LDR, val);
}

/* Start with all IRQs pointing to boot CPU.  IRQ balancing will shift them. */

static cpumask_t cluster_target_cpus(void)
{
	return cpumask_of_cpu(0);
}

static void cluster_send_IPI_mask(cpumask_t mask, int vector)
{
	send_IPI_mask_sequence(mask, vector);
}

static void cluster_send_IPI_allbutself(int vector)
{
	cpumask_t mask = cpu_online_map;

	cpu_clear(smp_processor_id(), mask);

	if (!cpus_empty(mask))
		cluster_send_IPI_mask(mask, vector);
}

static void cluster_send_IPI_all(int vector)
{
	cluster_send_IPI_mask(cpu_online_map, vector);
}

static int cluster_apic_id_registered(void)
{
	return 1;
}

static unsigned int cluster_cpu_mask_to_apicid(cpumask_t cpumask)
{
	int cpu;

	/*
	 * We're using fixed IRQ delivery, can only return one phys APIC ID.
	 * May as well be the first.
	 */
	cpu = first_cpu(cpumask);
	if ((unsigned)cpu < NR_CPUS)
		return x86_cpu_to_apicid[cpu];
	else
		return BAD_APICID;
}

/* cpuid returns the value latched in the HW at reset, not the APIC ID
 * register's value.  For any box whose BIOS changes APIC IDs, like
 * clustered APIC systems, we must use hard_smp_processor_id.
 *
 * See Intel's IA-32 SW Dev's Manual Vol2 under CPUID.
 */
static unsigned int phys_pkg_id(int index_msb)
{
	return hard_smp_processor_id() >> index_msb;
}

struct genapic apic_cluster = {
	.name = "clustered",
	.int_delivery_mode = dest_Fixed,
	.int_dest_mode = (APIC_DEST_PHYSICAL != 0),
	.int_delivery_dest = APIC_DEST_PHYSICAL | APIC_DM_FIXED,
	.target_cpus = cluster_target_cpus,
	.apic_id_registered = cluster_apic_id_registered,
	.init_apic_ldr = cluster_init_apic_ldr,
	.send_IPI_all = cluster_send_IPI_all,
	.send_IPI_allbutself = cluster_send_IPI_allbutself,
	.send_IPI_mask = cluster_send_IPI_mask,
	.cpu_mask_to_apicid = cluster_cpu_mask_to_apicid,
	.phys_pkg_id = phys_pkg_id,
};