From 681ee44d40d7c93b42118320e4620d07d8704fd6 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Tue, 9 Feb 2010 18:01:44 -0800 Subject: x86, apic: Don't use logical-flat mode when CPU hotplug may exceed 8 CPUs We need to fall back from logical-flat APIC mode to physical-flat mode when we have more than 8 CPUs. However, in the presence of CPU hotplug(with bios listing not enabled but possible cpus as disabled cpus in MADT), we have to consider the number of possible CPUs rather than the number of current CPUs; otherwise we may cross the 8-CPU boundary when CPUs are added later. 32bit apic code can use more cleanups (like the removal of vendor checks in 32bit default_setup_apic_routing()) and more unifications with 64bit code. Yinghai has some patches in works already. This patch addresses the boot issue that is reported in the virtualization guest context. [ hpa: incorporated function annotation feedback from Yinghai Lu ] Signed-off-by: Suresh Siddha LKML-Reference: <1265767304.2833.19.camel@sbs-t61.sc.intel.com> Acked-by: Shaohui Zheng Reviewed-by: Yinghai Lu Cc: Signed-off-by: H. Peter Anvin --- arch/x86/kernel/apic/probe_32.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) (limited to 'arch/x86/kernel/apic/probe_32.c') diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c index 1a6559f6768c..99d2fe016084 100644 --- a/arch/x86/kernel/apic/probe_32.c +++ b/arch/x86/kernel/apic/probe_32.c @@ -52,7 +52,32 @@ static int __init print_ipi_mode(void) } late_initcall(print_ipi_mode); -void default_setup_apic_routing(void) +void __init default_setup_apic_routing(void) +{ + int version = apic_version[boot_cpu_physical_apicid]; + + if (num_possible_cpus() > 8) { + switch (boot_cpu_data.x86_vendor) { + case X86_VENDOR_INTEL: + if (!APIC_XAPIC(version)) { + def_to_bigsmp = 0; + break; + } + /* If P4 and above fall through */ + case X86_VENDOR_AMD: + def_to_bigsmp = 1; + } + } + +#ifdef CONFIG_X86_BIGSMP + generic_bigsmp_probe(); +#endif + + if (apic->setup_apic_routing) + apic->setup_apic_routing(); +} + +static void setup_apic_flat_routing(void) { #ifdef CONFIG_X86_IO_APIC printk(KERN_INFO @@ -103,7 +128,7 @@ struct apic apic_default = { .init_apic_ldr = default_init_apic_ldr, .ioapic_phys_id_map = default_ioapic_phys_id_map, - .setup_apic_routing = default_setup_apic_routing, + .setup_apic_routing = setup_apic_flat_routing, .multi_timer_check = NULL, .apicid_to_node = default_apicid_to_node, .cpu_to_logical_apicid = default_cpu_to_logical_apicid, -- cgit v1.2.1