From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757205Ab2DFMkT (ORCPT ); Fri, 6 Apr 2012 08:40:19 -0400 Received: from mail-we0-f174.google.com ([74.125.82.174]:59227 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754945Ab2DFMkR (ORCPT ); Fri, 6 Apr 2012 08:40:17 -0400 From: Ido Yariv To: linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" Cc: Shai Fultheim , Ido Yariv Subject: [PATCH 1/2] vsmp: Fix number of CPUs when vsmp is disabled Date: Fri, 6 Apr 2012 15:39:46 +0300 Message-Id: <1333715987-26059-1-git-send-email-ido@wizery.com> X-Mailer: git-send-email 1.7.7.6 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Shai Fultheim In case CONFIG_X86_VSMP is not set, limit the number of CPUs to the number of CPUs of the first board. Signed-off-by: Shai Fultheim [ido@wizery.com: rebased, fixed minor coding-style issues] Signed-off-by: Ido Yariv --- arch/x86/kernel/vsmp_64.c | 48 +++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 48 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/vsmp_64.c b/arch/x86/kernel/vsmp_64.c index a1d804b..61571fd 100644 --- a/arch/x86/kernel/vsmp_64.c +++ b/arch/x86/kernel/vsmp_64.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -22,6 +23,8 @@ #include #include +#define TOPOLOGY_REGISTER_OFFSET 0x10 + #if defined CONFIG_PCI && defined CONFIG_PARAVIRT /* * Interrupt control on vSMPowered systems: @@ -149,12 +152,57 @@ int is_vsmp_box(void) return 0; } #endif + +#ifdef CONFIG_X86_VSMP + +static void __init vsmp_cap_cpus(void) +{ + /* VSMP is enabled, no need to cap cpus */ +} + +#else + +static void __init vsmp_cap_cpus(void) +{ + /* + * CONFIG_X86_VSMP is not configured, so limit the number CPUs to the + * ones present in the first board, unless explicitly overridden by + * setup_max_cpus + */ + if (setup_max_cpus == NR_CPUS) { + void __iomem *address; + unsigned int cfg, topology, node_shift, maxcpus; + + /* Read the vSMP Foundation topology register */ + cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0); + address = early_ioremap(cfg + TOPOLOGY_REGISTER_OFFSET, 4); + if (WARN_ON(!address)) + return; + + topology = readl(address); + node_shift = (topology >> 16) & 0x7; + if (!node_shift) + /* The value 0 should be decoded as 8 */ + node_shift = 8; + maxcpus = (topology & ((1 << node_shift) - 1)) + 1; + + printk(KERN_INFO "vSMP CTL: Capping CPUs to %d " + "(CONFIG_X86_VSMP is unset)\n", maxcpus); + setup_max_cpus = maxcpus; + early_iounmap(address, 4); + } +} + +#endif + void __init vsmp_init(void) { detect_vsmp_box(); if (!is_vsmp_box()) return; + vsmp_cap_cpus(); + set_vsmp_pv_ops(); return; } -- 1.7.7.6