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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0432C4332F for ; Thu, 3 Nov 2022 21:16:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230096AbiKCVQA (ORCPT ); Thu, 3 Nov 2022 17:16:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230147AbiKCVPt (ORCPT ); Thu, 3 Nov 2022 17:15:49 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2A4C175B4; Thu, 3 Nov 2022 14:15:48 -0700 (PDT) Date: Thu, 03 Nov 2022 21:15:45 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1667510147; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=IB0W7xPNDOn8m/Tr14513bKXWH9z/teXun0sfGesIEA=; b=lM5I3b+EcjGrF96EAAXO9Irf9g/x+yB1J3jLO3+Na9EmHo4lc5mF2Y/6eHndZRyh1tz5Dl SdY3tHL9g6eLl5iN83vLYsrfTFg5Wycbbk0UxWuXvJ6hNBk2PEVrrqedKk9n4lH/7oKUxB ajV0yG74lvkC5pkbhIu0gVMFwAAguPRPq3T6cxIzt1JT40oWTPF5Hg857oyfwfCTm7d25t kEaWIaZNMckChfwpueUZLhy0iL8+u4ctXBdePY306zgEBDUT9rMrmtmfoFQDt6ZA0rsTbz GSJOZN4UVIh6iAHVNUmLEk3yFdJ2HXBZRdsoV3sHTl3hI5XhByQqsGQunHLgfw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1667510147; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=IB0W7xPNDOn8m/Tr14513bKXWH9z/teXun0sfGesIEA=; b=5sDccz53Uh/IG6LG7txpbt0Ul7961HxLXQfc6Vp7RXJpiRrRBTej5eQP8ZIYoNE4g0Gy3j X0g/KbH5lVnIVyBQ== From: "tip-bot2 for Peter Zijlstra" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/mm] x86/mm/pae: Get rid of set_64bit() Cc: "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org MIME-Version: 1.0 Message-ID: <166751014599.6127.12396632902522246604.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/mm branch of tip: Commit-ID: b6e3ea033d08b368fcac28556fa27bf20e8a1ba5 Gitweb: https://git.kernel.org/tip/b6e3ea033d08b368fcac28556fa27bf20e8a1ba5 Author: Peter Zijlstra AuthorDate: Fri, 21 Oct 2022 13:36:24 +02:00 Committer: Peter Zijlstra CommitterDate: Thu, 03 Nov 2022 22:04:29 +01:00 x86/mm/pae: Get rid of set_64bit() Recognise that set_64bit() is a special case of our previously introduced pxx_xchg64(), so use that and get rid of set_64bit(). Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20221022114425.233481884%40infradead.org --- arch/x86/include/asm/cmpxchg_32.h | 28 +-------------------------- arch/x86/include/asm/pgtable-3level.h | 23 ++++++++++----------- 2 files changed, 12 insertions(+), 39 deletions(-) diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h index 215f5a6..6ba80ce 100644 --- a/arch/x86/include/asm/cmpxchg_32.h +++ b/arch/x86/include/asm/cmpxchg_32.h @@ -7,34 +7,6 @@ * you need to test for the feature in boot_cpu_data. */ -/* - * CMPXCHG8B only writes to the target if we had the previous - * value in registers, otherwise it acts as a read and gives us the - * "new previous" value. That is why there is a loop. Preloading - * EDX:EAX is a performance optimization: in the common case it means - * we need only one locked operation. - * - * A SIMD/3DNOW!/MMX/FPU 64-bit store here would require at the very - * least an FPU save and/or %cr0.ts manipulation. - * - * cmpxchg8b must be used with the lock prefix here to allow the - * instruction to be executed atomically. We need to have the reader - * side to see the coherent 64bit value. - */ -static inline void set_64bit(volatile u64 *ptr, u64 value) -{ - u32 low = value; - u32 high = value >> 32; - u64 prev = *ptr; - - asm volatile("\n1:\t" - LOCK_PREFIX "cmpxchg8b %0\n\t" - "jnz 1b" - : "=m" (*ptr), "+A" (prev) - : "b" (low), "c" (high) - : "memory"); -} - #ifdef CONFIG_X86_CMPXCHG64 #define arch_cmpxchg64(ptr, o, n) \ ((__typeof__(*(ptr)))__cmpxchg64((ptr), (unsigned long long)(o), \ diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h index 93c82c6..967b135 100644 --- a/arch/x86/include/asm/pgtable-3level.h +++ b/arch/x86/include/asm/pgtable-3level.h @@ -19,7 +19,15 @@ pr_err("%s:%d: bad pgd %p(%016Lx)\n", \ __FILE__, __LINE__, &(e), pgd_val(e)) -/* Rules for using set_pte: the pte being assigned *must* be +#define pxx_xchg64(_pxx, _ptr, _val) ({ \ + _pxx##val_t *_p = (_pxx##val_t *)_ptr; \ + _pxx##val_t _o = *_p; \ + do { } while (!try_cmpxchg64(_p, &_o, (_val))); \ + native_make_##_pxx(_o); \ +}) + +/* + * Rules for using set_pte: the pte being assigned *must* be * either not present or in a state where the hardware will * not attempt to update the pte. In places where this is * not possible, use pte_get_and_clear to obtain the old pte @@ -34,12 +42,12 @@ static inline void native_set_pte(pte_t *ptep, pte_t pte) static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte) { - set_64bit((unsigned long long *)(ptep), native_pte_val(pte)); + pxx_xchg64(pte, ptep, native_pte_val(pte)); } static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd) { - set_64bit((unsigned long long *)(pmdp), native_pmd_val(pmd)); + pxx_xchg64(pmd, pmdp, native_pmd_val(pmd)); } static inline void native_set_pud(pud_t *pudp, pud_t pud) @@ -47,7 +55,7 @@ static inline void native_set_pud(pud_t *pudp, pud_t pud) #ifdef CONFIG_PAGE_TABLE_ISOLATION pud.p4d.pgd = pti_set_user_pgtbl(&pudp->p4d.pgd, pud.p4d.pgd); #endif - set_64bit((unsigned long long *)(pudp), native_pud_val(pud)); + pxx_xchg64(pud, pudp, native_pud_val(pud)); } /* @@ -91,13 +99,6 @@ static inline void pud_clear(pud_t *pudp) } -#define pxx_xchg64(_pxx, _ptr, _val) ({ \ - _pxx##val_t *_p = (_pxx##val_t *)_ptr; \ - _pxx##val_t _o = *_p; \ - do { } while (!try_cmpxchg64(_p, &_o, (_val))); \ - native_make_##_pxx(_o); \ -}) - #ifdef CONFIG_SMP static inline pte_t native_ptep_get_and_clear(pte_t *ptep) {