Commit-ID: 411cf9ee2946492c0ac7eca48422fcf94a723ce5 Gitweb: http://git.kernel.org/tip/411cf9ee2946492c0ac7eca48422fcf94a723ce5 Author: Oren Twaig <o...@scalemp.com> AuthorDate: Sun, 29 Jun 2014 13:01:08 +0300 Committer: H. Peter Anvin <h...@zytor.com> CommitDate: Sun, 13 Jul 2014 17:48:03 -0700
x86, vsmp: Remove is_vsmp_box() from apic_is_clustered_box() When a vSMP Foundation box is detected, the function apic_cluster_num() counts the number of APIC clusters found. If more than one found, a multi board configuration is assumed, and TSC marked as unstable. This behavior is incorrect as vSMP Foundation may use processors from single node only, attached to memory of other nodes - and such node may have more than one APIC cluster (typically any recent intel box has more than single APIC_CLUSTERID(x)). To fix this, we simply remove the code which detects a vSMP Foundation box and affects apic_is_clusted_box() return value. This can be done because later the kernel checks by itself if the TSC is stable using the check_tsc_sync_[source|target]() functions and marks TSC as unstable if needed. Acked-by: Shai Fultheim <s...@scalemp.com> Signed-off-by: Oren Twaig <o...@scalemp.com> Link: http://lkml.kernel.org/r/1404036068-11674-1-git-send-email-o...@scalemp.com Signed-off-by: H. Peter Anvin <h...@zytor.com> --- arch/x86/include/asm/apic.h | 8 ------ arch/x86/kernel/apic/apic.c | 60 +-------------------------------------------- 2 files changed, 1 insertion(+), 67 deletions(-) diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 69ed79a..b40ea7e 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -85,14 +85,6 @@ static inline bool apic_from_smp_config(void) #include <asm/paravirt.h> #endif -#ifdef CONFIG_X86_64 -extern int is_vsmp_box(void); -#else -static inline int is_vsmp_box(void) -{ - return 0; -} -#endif extern int setup_profiling_timer(unsigned int); static inline void native_apic_mem_write(u32 reg, u32 v) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index ca1bd75..6b35d30 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -2451,51 +2451,6 @@ static void apic_pm_activate(void) { } #ifdef CONFIG_X86_64 -static int apic_cluster_num(void) -{ - int i, clusters, zeros; - unsigned id; - u16 *bios_cpu_apicid; - DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS); - - bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid); - bitmap_zero(clustermap, NUM_APIC_CLUSTERS); - - for (i = 0; i < nr_cpu_ids; i++) { - /* are we being called early in kernel startup? */ - if (bios_cpu_apicid) { - id = bios_cpu_apicid[i]; - } else if (i < nr_cpu_ids) { - if (cpu_present(i)) - id = per_cpu(x86_bios_cpu_apicid, i); - else - continue; - } else - break; - - if (id != BAD_APICID) - __set_bit(APIC_CLUSTERID(id), clustermap); - } - - /* Problem: Partially populated chassis may not have CPUs in some of - * the APIC clusters they have been allocated. Only present CPUs have - * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap. - * Since clusters are allocated sequentially, count zeros only if - * they are bounded by ones. - */ - clusters = 0; - zeros = 0; - for (i = 0; i < NUM_APIC_CLUSTERS; i++) { - if (test_bit(i, clustermap)) { - clusters += 1 + zeros; - zeros = 0; - } else - ++zeros; - } - - return clusters; -} - static int multi_checked; static int multi; @@ -2540,20 +2495,7 @@ static void dmi_check_multi(void) int apic_is_clustered_box(void) { dmi_check_multi(); - if (multi) - return 1; - - if (!is_vsmp_box()) - return 0; - - /* - * ScaleMP vSMPowered boxes have one cluster per board and TSCs are - * not guaranteed to be synced between boards - */ - if (apic_cluster_num() > 1) - return 1; - - return 0; + return multi; } #endif -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
