From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9A48C00449 for ; Mon, 8 Oct 2018 09:58:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 750F52087C for ; Mon, 8 Oct 2018 09:58:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 750F52087C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727463AbeJHRJs (ORCPT ); Mon, 8 Oct 2018 13:09:48 -0400 Received: from terminus.zytor.com ([198.137.202.136]:45441 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726193AbeJHRJs (ORCPT ); Mon, 8 Oct 2018 13:09:48 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w989wDAI560212 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 8 Oct 2018 02:58:14 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w989wD7d560209; Mon, 8 Oct 2018 02:58:13 -0700 Date: Mon, 8 Oct 2018 02:58:13 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: "tip-bot for Chang S. Bae" Message-ID: Cc: torvalds@linux-foundation.org, chang.seok.bae@intel.com, hpa@zytor.com, dave.hansen@linux.intel.com, peterz@infradead.org, ravi.v.shankar@intel.com, dvlasenk@redhat.com, markus.t.metzger@intel.com, linux-kernel@vger.kernel.org, brgerst@gmail.com, mingo@kernel.org, luto@kernel.org, riel@surriel.com, luto@amacapital.net, tglx@linutronix.de, bp@alien8.de Reply-To: mingo@kernel.org, riel@surriel.com, luto@kernel.org, tglx@linutronix.de, bp@alien8.de, luto@amacapital.net, hpa@zytor.com, torvalds@linux-foundation.org, chang.seok.bae@intel.com, dave.hansen@linux.intel.com, peterz@infradead.org, markus.t.metzger@intel.com, ravi.v.shankar@intel.com, dvlasenk@redhat.com, brgerst@gmail.com, linux-kernel@vger.kernel.org In-Reply-To: <1537312139-5580-8-git-send-email-chang.seok.bae@intel.com> References: <1537312139-5580-8-git-send-email-chang.seok.bae@intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/asm] x86/vdso: Introduce helper functions for CPU and node number Git-Commit-ID: ffebbaedc8616cffe648202e364dce6a045d65a2 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: ffebbaedc8616cffe648202e364dce6a045d65a2 Gitweb: https://git.kernel.org/tip/ffebbaedc8616cffe648202e364dce6a045d65a2 Author: Chang S. Bae AuthorDate: Tue, 18 Sep 2018 16:08:58 -0700 Committer: Ingo Molnar CommitDate: Mon, 8 Oct 2018 10:41:10 +0200 x86/vdso: Introduce helper functions for CPU and node number Clean up the CPU/node number related code a bit, to make it more apparent how we are encoding/extracting the CPU and node fields from the segment limit. No change in functionality intended. [ mingo: Wrote new changelog. ] Suggested-by: Andy Lutomirski Suggested-by: Thomas Gleixner Signed-off-by: Chang S. Bae Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Markus T Metzger Cc: Peter Zijlstra Cc: Ravi Shankar Cc: Rik van Riel Link: http://lkml.kernel.org/r/1537312139-5580-8-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar --- arch/x86/entry/vdso/vgetcpu.c | 9 +-------- arch/x86/entry/vdso/vma.c | 19 +++++++------------ arch/x86/include/asm/segment.h | 41 +++++++++++++++++++++++++++++++++++++++++ arch/x86/include/asm/vgtod.h | 26 -------------------------- 4 files changed, 49 insertions(+), 46 deletions(-) diff --git a/arch/x86/entry/vdso/vgetcpu.c b/arch/x86/entry/vdso/vgetcpu.c index 8ec3d1f4ce9a..de78fc9cd963 100644 --- a/arch/x86/entry/vdso/vgetcpu.c +++ b/arch/x86/entry/vdso/vgetcpu.c @@ -13,14 +13,7 @@ notrace long __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused) { - unsigned int p; - - p = __getcpu(); - - if (cpu) - *cpu = p & VGETCPU_CPU_MASK; - if (node) - *node = p >> 12; + vdso_read_cpu_node(cpu, node); return 0; } diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 0b114aafcedc..39b5584c5808 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -339,20 +339,15 @@ static void vgetcpu_cpu_init(void *arg) { int cpu = smp_processor_id(); struct desc_struct d = { }; - unsigned long node = 0; -#ifdef CONFIG_NUMA - node = cpu_to_node(cpu); -#endif + unsigned long cpudata = vdso_encode_cpu_node(cpu, cpu_to_node(cpu)); + if (static_cpu_has(X86_FEATURE_RDTSCP)) - write_rdtscp_aux((node << 12) | cpu); + write_rdtscp_aux(cpudata); + + /* Store CPU and node number in limit */ + d.limit0 = cpudata; + d.limit1 = cpudata >> 16; - /* - * Store cpu number in limit so that it can be loaded - * quickly in user space in vgetcpu. (12 bits for the CPU - * and 8 bits for the node) - */ - d.limit0 = cpu | ((node & 0xf) << 12); - d.limit1 = node >> 4; d.type = 5; /* RO data, expand down, accessed */ d.dpl = 3; /* Visible to user code */ d.s = 1; /* Not a system segment */ diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index e3e788ea52e5..4d1f6cc62e13 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -224,6 +224,47 @@ #define GDT_ENTRY_TLS_ENTRIES 3 #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES* 8) +#ifdef CONFIG_X86_64 + +/* Bit size and mask of CPU number stored in the per CPU data (and TSC_AUX) */ +#define VDSO_CPU_SIZE 12 +#define VDSO_CPU_MASK 0xfff + +#ifndef __ASSEMBLY__ + +/* Helper functions to store/load CPU and node numbers */ + +static inline unsigned long vdso_encode_cpu_node(int cpu, unsigned long node) +{ + return ((node << VDSO_CPU_SIZE) | cpu); +} + +static inline void vdso_read_cpu_node(unsigned *cpu, unsigned *node) +{ + unsigned int p; + + /* + * Load CPU and node number from GDT. LSL is faster than RDTSCP + * and works on all CPUs. This is volatile so that it orders + * correctly with respect to barrier() and to keep GCC from cleverly + * hoisting it out of the calling function. + * + * If RDPID is available, use it. + */ + alternative_io ("lsl %[seg],%[p]", + ".byte 0xf3,0x0f,0xc7,0xf8", /* RDPID %eax/rax */ + X86_FEATURE_RDPID, + [p] "=a" (p), [seg] "r" (__CPU_NUMBER_SEG)); + + if (cpu) + *cpu = (p & VDSO_CPU_MASK); + if (node) + *node = (p >> VDSO_CPU_SIZE); +} + +#endif /* !__ASSEMBLY__ */ +#endif /* CONFIG_X86_64 */ + #ifdef __KERNEL__ /* diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h index 4e81ea920722..056a61c8c5c7 100644 --- a/arch/x86/include/asm/vgtod.h +++ b/arch/x86/include/asm/vgtod.h @@ -77,30 +77,4 @@ static inline void gtod_write_end(struct vsyscall_gtod_data *s) ++s->seq; } -#ifdef CONFIG_X86_64 - -#define VGETCPU_CPU_MASK 0xfff - -static inline unsigned int __getcpu(void) -{ - unsigned int p; - - /* - * Load CPU (and node) number from GDT. LSL is faster than RDTSCP - * and works on all CPUs. This is volatile so that it orders - * correctly with respect to barrier() and to keep GCC from cleverly - * hoisting it out of the calling function. - * - * If RDPID is available, use it. - */ - alternative_io ("lsl %[seg],%[p]", - ".byte 0xf3,0x0f,0xc7,0xf8", /* RDPID %eax/rax */ - X86_FEATURE_RDPID, - [p] "=a" (p), [seg] "r" (__CPU_NUMBER_SEG)); - - return p; -} - -#endif /* CONFIG_X86_64 */ - #endif /* _ASM_X86_VGTOD_H */