From d3bd058826aa8b79590cca6c8e6d1557bf576ada Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Thu, 16 Dec 2010 19:09:58 -0800 Subject: x86, acpi: Parse all SRAT cpu entries even above the cpu number limitation Recent Intel new system have different order in MADT, aka will list all thread0 at first, then all thread1. But SRAT table still old order, it will list cpus in one socket all together. If the user have compiled limited NR_CPUS or boot with nr_cpus=, could have missed to put some cpus apic id to node mapping into apicid_to_node[]. for example for 4 sockets system with 64 cpus with nr_cpus=32 will get crash... [ 9.106288] Total of 32 processors activated (136190.88 BogoMIPS). [ 9.235021] divide error: 0000 [#1] SMP [ 9.235315] last sysfs file: [ 9.235481] CPU 1 [ 9.235592] Modules linked in: [ 9.245398] [ 9.245478] Pid: 2, comm: kthreadd Not tainted 2.6.37-rc1-tip-yh-01782-ge92ef79-dirty #274 /Sun Fire x4800 [ 9.265415] RIP: 0010:[] [] select_task_rq_fair+0x4f0/0x623 ... [ 9.645938] RIP [] select_task_rq_fair+0x4f0/0x623 [ 9.665356] RSP [ 9.665568] ---[ end trace 2296156d35fdfc87 ]--- So let just parse all cpu entries in SRAT. Also add apicid checking with MAX_LOCAL_APIC, in case We could out of boundaries of apicid_to_node[]. it fixes following bug too. https://bugzilla.kernel.org/show_bug.cgi?id=22662 -v2: expand to 32bit according to hpa need to add MAX_LOCAL_APIC for 32bit Reported-and-Tested-by: Wu Fengguang Reported-by: Bjorn Helgaas Tested-by: Myron Stowe Signed-off-by: Yinghai Lu LKML-Reference: <4D0AD486.9020704@kernel.org> Signed-off-by: H. Peter Anvin --- arch/x86/kernel/acpi/boot.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/x86/kernel/acpi') diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index c05872aa3ce0..f19d6679600f 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -198,6 +198,11 @@ static void __cpuinit acpi_register_lapic(int id, u8 enabled) { unsigned int ver = 0; + if (id >= (MAX_LOCAL_APIC-1)) { + printk(KERN_INFO PREFIX "skipped apicid that is too big\n"); + return; + } + if (!enabled) { ++disabled_cpus; return; -- cgit v1.2.2 From cb2ded37fd2e1039f96c8c892da024a8f033add5 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 4 Jan 2011 16:38:52 -0800 Subject: x86: Fix APIC ID sizing bug on larger systems, clean up MAX_APICS confusion Found one x2apic pre-enabled system, x2apic_mode suddenly get corrupted after register some cpus, when compiled CONFIG_NR_CPUS=255 instead of 512. It turns out that generic_processor_info() ==> phyid_set(apicid, phys_cpu_present_map) causes the problem. phys_cpu_present_map is sized by MAX_APICS bits, and pre-enabled system some cpus have an apic id > 255. The variable after phys_cpu_present_map may get corrupted silently: ffffffff828e8420 B phys_cpu_present_map ffffffff828e8440 B apic_verbosity ffffffff828e8444 B local_apic_timer_c2_ok ffffffff828e8448 B disable_apic ffffffff828e844c B x2apic_mode ffffffff828e8450 B x2apic_disabled ffffffff828e8454 B num_processors ... Actually phys_cpu_present_map is referenced via apic id, instead index. We should use MAX_LOCAL_APIC instead MAX_APICS. For 64-bit it will be 32768 in all cases. BSS will increase by 4k bytes on 64-bit: text data bss dec filename 21696943 4193748 12787712 38678403 vmlinux.before 21696943 4193748 12791808 38682499 vmlinux.after No change on 32bit. Finally we can remove MAX_APCIS that was rather confusing. Signed-off-by: Yinghai Lu Cc: H. Peter Anvin Cc: "Eric W. Biederman" LKML-Reference: <4D23BD9C.3070102@kernel.org> Signed-off-by: Ingo Molnar --- arch/x86/kernel/acpi/boot.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/acpi') diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 7235e5fbdb6d..17c8090fabd4 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -915,13 +915,13 @@ static int __init acpi_parse_madt_lapic_entries(void) acpi_register_lapic_address(acpi_lapic_addr); count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_SAPIC, - acpi_parse_sapic, MAX_APICS); + acpi_parse_sapic, MAX_LOCAL_APIC); if (!count) { x2count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_X2APIC, - acpi_parse_x2apic, MAX_APICS); + acpi_parse_x2apic, MAX_LOCAL_APIC); count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC, - acpi_parse_lapic, MAX_APICS); + acpi_parse_lapic, MAX_LOCAL_APIC); } if (!count && !x2count) { printk(KERN_ERR PREFIX "No LAPIC entries present\n"); -- cgit v1.2.2