/*
* 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,
};
