From 947134d9b00f342415af7eddd42a5fce7262a1b9 Mon Sep 17 00:00:00 2001 From: Prarit Bhargava Date: Mon, 4 Dec 2017 11:45:21 -0500 Subject: x86/smpboot: Do not use smp_num_siblings in __max_logical_packages calculation Documentation/x86/topology.txt defines smp_num_siblings as "The number of threads in a core". Since commit bbb65d2d365e ("x86: use cpuid vector 0xb when available for detecting cpu topology") smp_num_siblings is the maximum number of threads in a core. If Simultaneous MultiThreading (SMT) is disabled on a system, smp_num_siblings is 2 and not 1 as expected. Use topology_max_smt_threads(), which contains the active numer of threads, in the __max_logical_packages calculation. On a single socket, single core, single thread system __max_smt_threads has not been updated when the __max_logical_packages calculation happens, so its zero which makes the package estimate fail. Initialize it to one, which is the minimum number of threads on a core. [ tglx: Folded the __max_smt_threads fix in ] Fixes: b4c0a7326f5d ("x86/smpboot: Fix __max_logical_packages estimate") Reported-by: Jakub Kicinski Signed-off-by: Prarit Bhargava Tested-by: Jakub Kicinski Cc: netdev@vger.kernel.org Cc: "netdev@vger.kernel.org" Cc: Clark Williams Link: https://lkml.kernel.org/r/20171204164521.17870-1-prarit@redhat.com --- arch/x86/kernel/smpboot.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/kernel/smpboot.c') diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 05a97d5fe298..35cb20994e32 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -106,7 +106,7 @@ EXPORT_SYMBOL(__max_logical_packages); static unsigned int logical_packages __read_mostly; /* Maximum number of SMT threads on any online core */ -int __max_smt_threads __read_mostly; +int __read_mostly __max_smt_threads = 1; /* Flag to indicate if a complete sched domain rebuild is required */ bool x86_topology_update; @@ -1304,7 +1304,7 @@ void __init native_smp_cpus_done(unsigned int max_cpus) * Today neither Intel nor AMD support heterogenous systems so * extrapolate the boot cpu's data to all packages. */ - ncpus = cpu_data(0).booted_cores * smp_num_siblings; + ncpus = cpu_data(0).booted_cores * topology_max_smt_threads(); __max_logical_packages = DIV_ROUND_UP(nr_cpu_ids, ncpus); pr_info("Max logical packages: %u\n", __max_logical_packages); -- cgit From 613e396bc0d4c7604fba23256644e78454c68cf6 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 17 Dec 2017 10:56:29 +0100 Subject: init: Invoke init_espfix_bsp() from mm_init() init_espfix_bsp() needs to be invoked before the page table isolation initialization. Move it into mm_init() which is the place where pti_init() will be added. While at it get rid of the #ifdeffery and provide proper stub functions. Signed-off-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Signed-off-by: Ingo Molnar --- arch/x86/kernel/smpboot.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'arch/x86/kernel/smpboot.c') diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index d56c1d209283..33d6000265aa 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -990,12 +990,8 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle, initial_code = (unsigned long)start_secondary; initial_stack = idle->thread.sp; - /* - * Enable the espfix hack for this CPU - */ -#ifdef CONFIG_X86_ESPFIX64 + /* Enable the espfix hack for this CPU */ init_espfix_ap(cpu); -#endif /* So we see what's up */ announce_cpu(cpu, apicid); -- cgit From 322f8b8b340c824aef891342b0f5795d15e11562 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 30 Dec 2017 22:13:53 +0100 Subject: x86/smpboot: Remove stale TLB flush invocations smpboot_setup_warm_reset_vector() and smpboot_restore_warm_reset_vector() invoke local_flush_tlb() for no obvious reason. Digging in history revealed that the original code in the 2.1 era added those because the code manipulated a swapper_pg_dir pagetable entry. The pagetable manipulation was removed long ago in the 2.3 timeframe, but the TLB flush invocations stayed around forever. Remove them along with the pointless pr_debug()s which come from the same 2.1 change. Reported-by: Dominik Brodowski Signed-off-by: Thomas Gleixner Cc: Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Linus Torvalds Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20171230211829.586548655@linutronix.de Signed-off-by: Ingo Molnar --- arch/x86/kernel/smpboot.c | 9 --------- 1 file changed, 9 deletions(-) (limited to 'arch/x86/kernel/smpboot.c') diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 33d6000265aa..c3402fc30865 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -128,25 +128,16 @@ static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip) spin_lock_irqsave(&rtc_lock, flags); CMOS_WRITE(0xa, 0xf); spin_unlock_irqrestore(&rtc_lock, flags); - local_flush_tlb(); - pr_debug("1.\n"); *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_HIGH)) = start_eip >> 4; - pr_debug("2.\n"); *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = start_eip & 0xf; - pr_debug("3.\n"); } static inline void smpboot_restore_warm_reset_vector(void) { unsigned long flags; - /* - * Install writable page 0 entry to set BIOS data area. - */ - local_flush_tlb(); - /* * Paranoid: Set warm reset code and vector here back * to default values. -- cgit