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Commit 18a2b647 authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds
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[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: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 75152114

arch/x86_64/kernel/mpparse.c

+14 −6
Original line number Diff line number Diff line
@@ -107,6 +107,7 @@ static int __init mpf_checksum(unsigned char *mp, int len) 
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 @@ static void __init MP_processor_info (struct mpc_config_processor *m) 
			" 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 @@ static void __init MP_processor_info (struct mpc_config_processor *m) 
		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)

arch/x86_64/kernel/smpboot.c

+0 −2
Original line number Diff line number Diff line
@@ -645,7 +645,6 @@ static int __cpuinit do_boot_cpu(int cpu, int apicid) 
		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 @@ void __cpuinit smp_prepare_cpus(unsigned int max_cpus) 
		      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