[PATCH] x86_64: Don't assume BSP has ID 0 in new smp bootup
This patch removes the assumption that LAPIC entries contain the BSP as its
first entry. This is a slight improvement to the temporary fix submitted by
Suresh Siddha.
- Removes assumption that LAPIC entries contain BSP first.
- Builds x86_acpiid_to_apicid[] and bios_cpu_apicid[] properly with BSP as
first entry.
- Made maxcpus=1 boot on these systems. Since the parsing earlier in
arch/x86_64/kernel/mpparse.c stopped after maxcpus entries, other entries
were not processed, this causes kernel not to boot on these systems.
TBD: x86_acpiid_to_apicid and bios_cpu_apicid[] seem to be exactly the
same. This could be removed, but might need more work to cleanup.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/mpparse.c b/arch/x86_64/kernel/mpparse.c
index f221231..f86d9db 100644
--- a/arch/x86_64/kernel/mpparse.c
+++ b/arch/x86_64/kernel/mpparse.c
@@ -107,6 +107,7 @@
static void __init MP_processor_info (struct mpc_config_processor *m)
{
int ver;
+ static int found_bsp=0;
if (!(m->mpc_cpuflag & CPU_ENABLED))
return;
@@ -126,11 +127,6 @@
" Processor ignored.\n", NR_CPUS);
return;
}
- if (num_processors >= maxcpus) {
- printk(KERN_WARNING "WARNING: maxcpus limit of %i reached."
- " Processor ignored.\n", maxcpus);
- return;
- }
num_processors++;
@@ -150,7 +146,19 @@
ver = 0x10;
}
apic_version[m->mpc_apicid] = ver;
- bios_cpu_apicid[num_processors - 1] = m->mpc_apicid;
+ if (m->mpc_cpuflag & CPU_BOOTPROCESSOR) {
+ /*
+ * bios_cpu_apicid is required to have processors listed
+ * in same order as logical cpu numbers. Hence the first
+ * entry is BSP, and so on.
+ */
+ bios_cpu_apicid[0] = m->mpc_apicid;
+ x86_cpu_to_apicid[0] = m->mpc_apicid;
+ found_bsp = 1;
+ } else {
+ bios_cpu_apicid[num_processors - found_bsp] = m->mpc_apicid;
+ x86_cpu_to_apicid[num_processors - found_bsp] = m->mpc_apicid;
+ }
}
static void __init MP_bus_info (struct mpc_config_bus *m)
diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index d00e494..5abdee1 100644
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -645,7 +645,6 @@
printk("failed fork for CPU %d\n", cpu);
return PTR_ERR(idle);
}
- x86_cpu_to_apicid[cpu] = apicid;
cpu_pda[cpu].pcurrent = idle;
@@ -954,7 +953,6 @@
GET_APIC_ID(apic_read(APIC_ID)), boot_cpu_id);
/* Or can we switch back to PIC here? */
}
- x86_cpu_to_apicid[0] = boot_cpu_id;
/*
* Now start the IO-APICs