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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F7A0C433EF for ; Mon, 15 Nov 2021 16:55:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7035661B5F for ; Mon, 15 Nov 2021 16:55:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231328AbhKOQ6H (ORCPT ); Mon, 15 Nov 2021 11:58:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33130 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230254AbhKOQ5p (ORCPT ); Mon, 15 Nov 2021 11:57:45 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B8624C061714 for ; Mon, 15 Nov 2021 08:54:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=eDF+PT/lT22ezS73apcdD8wnw6ClAL+truZnktg303A=; b=dUIsrp6v9c0JNNeGch4qU6C542 CuYNGENmu1zvcyd+FeePCLxITLrEiH+F06PVdCT4T/n+aIfmuNhPbfd2e+l3/NXZZeVLp+/I8LGtn YzzJMkX6fDFh3N/wuShAbBJ3YFe0CLyIsDpTrXDxzo+3a5ziTM6xG8QW7sJjQ0TEgoXXe1XIpwttx 6P2mkOiqC5jjyZ53jwW0bmmWERlAy3tsCdaPUoq9Kf9OWVjFbPl5wxmlNXbPPyQZkCpXar1WNRggT OuLhig5RNKvZ4xAkB1Qf733KI77BgKBYjHQzu58K4qRV8IyJW76VtRUyKeqeLI5VmX/Op8kvjW4Yj pcNBq9ag==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mmfFd-00GAjb-NS; Mon, 15 Nov 2021 16:54:38 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 2BD92300129; Mon, 15 Nov 2021 17:54:37 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 0EA7F20BE2263; Mon, 15 Nov 2021 17:54:37 +0100 (CET) Date: Mon, 15 Nov 2021 17:54:37 +0100 From: Peter Zijlstra To: x86@kernel.orgg Cc: linux-kernel@vger.kernel.org, jpoimboe@redhat.com, mark.rutland@arm.com, dvyukov@google.com, seanjc@google.com, pbonzini@redhat.com, mbenes@suse.cz Subject: [PATCH v2.1 02/23] x86/mmx_32: Remove X86_USE_3DNOW Message-ID: References: <20211110100102.250793167@infradead.org> <20211110101325.009464367@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211110101325.009464367@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The alternative (har har) for this patch is the below, which seems favoured by Boris. --- Subject: x86/mmx_32: Remove X86_USE_3DNOW From: Peter Zijlstra Date: Mon Nov 15 17:46:39 CET 2021 This code puts an exception table entry on the PREFETCH instruction to overwrite it with a JMP.d8 when it triggers an exception. Except of course, our code is no longer writable, also SMP. Instead of fixing this broken mess, simply take it out. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/Kconfig | 2 arch/x86/Kconfig.cpu | 4 arch/x86/include/asm/mmx.h | 15 arch/x86/include/asm/page_32.h | 14 arch/x86/include/asm/required-features.h | 4 arch/x86/include/asm/string_32.h | 33 -- arch/x86/lib/Makefile | 1 arch/x86/lib/memcpy_32.c | 4 arch/x86/lib/mmx_32.c | 388 ------------------------- arch/x86/lib/usercopy_32.c | 1 tools/arch/x86/include/asm/required-features.h | 4 11 files changed, 1 insertion(+), 469 deletions(-) --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1945,7 +1945,7 @@ config EFI config EFI_STUB bool "EFI stub support" - depends on EFI && !X86_USE_3DNOW + depends on EFI depends on $(cc-option,-mabi=ms) || X86_32 select RELOCATABLE help --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -342,10 +342,6 @@ config X86_USE_PPRO_CHECKSUM def_bool y depends on MWINCHIP3D || MWINCHIPC6 || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MK8 || MVIAC3_2 || MVIAC7 || MEFFICEON || MGEODE_LX || MCORE2 || MATOM -config X86_USE_3DNOW - def_bool y - depends on (MCYRIXIII || MK7 || MGEODE_LX) && !UML - # # P6_NOPs are a relatively minor optimization that require a family >= # 6 processor, except that it is broken on certain VIA chips. --- a/arch/x86/include/asm/mmx.h +++ b/arch/x86/include/asm/mmx.h @@ -1,15 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _ASM_X86_MMX_H -#define _ASM_X86_MMX_H - -/* - * MMX 3Dnow! helper operations - */ - -#include - -extern void *_mmx_memcpy(void *to, const void *from, size_t size); -extern void mmx_clear_page(void *page); -extern void mmx_copy_page(void *to, void *from); - -#endif /* _ASM_X86_MMX_H */ --- a/arch/x86/include/asm/page_32.h +++ b/arch/x86/include/asm/page_32.h @@ -19,19 +19,6 @@ extern unsigned long __phys_addr(unsigne #define pfn_valid(pfn) ((pfn) < max_mapnr) #endif /* CONFIG_FLATMEM */ -#ifdef CONFIG_X86_USE_3DNOW -#include - -static inline void clear_page(void *page) -{ - mmx_clear_page(page); -} - -static inline void copy_page(void *to, void *from) -{ - mmx_copy_page(to, from); -} -#else /* !CONFIG_X86_USE_3DNOW */ #include static inline void clear_page(void *page) @@ -43,7 +30,6 @@ static inline void copy_page(void *to, v { memcpy(to, from, PAGE_SIZE); } -#endif /* CONFIG_X86_USE_3DNOW */ #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_PAGE_32_H */ --- a/arch/x86/include/asm/required-features.h +++ b/arch/x86/include/asm/required-features.h @@ -35,11 +35,7 @@ # define NEED_CMOV 0 #endif -#ifdef CONFIG_X86_USE_3DNOW -# define NEED_3DNOW (1<<(X86_FEATURE_3DNOW & 31)) -#else # define NEED_3DNOW 0 -#endif #if defined(CONFIG_X86_P6_NOP) || defined(CONFIG_X86_64) # define NEED_NOPL (1<<(X86_FEATURE_NOPL & 31)) --- a/arch/x86/include/asm/string_32.h +++ b/arch/x86/include/asm/string_32.h @@ -146,42 +146,9 @@ static __always_inline void *__constant_ extern void *memcpy(void *, const void *, size_t); #ifndef CONFIG_FORTIFY_SOURCE -#ifdef CONFIG_X86_USE_3DNOW - -#include - -/* - * This CPU favours 3DNow strongly (eg AMD Athlon) - */ - -static inline void *__constant_memcpy3d(void *to, const void *from, size_t len) -{ - if (len < 512) - return __constant_memcpy(to, from, len); - return _mmx_memcpy(to, from, len); -} - -static inline void *__memcpy3d(void *to, const void *from, size_t len) -{ - if (len < 512) - return __memcpy(to, from, len); - return _mmx_memcpy(to, from, len); -} - -#define memcpy(t, f, n) \ - (__builtin_constant_p((n)) \ - ? __constant_memcpy3d((t), (f), (n)) \ - : __memcpy3d((t), (f), (n))) - -#else - -/* - * No 3D Now! - */ #define memcpy(t, f, n) __builtin_memcpy(t, f, n) -#endif #endif /* !CONFIG_FORTIFY_SOURCE */ #define __HAVE_ARCH_MEMMOVE --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -63,7 +63,6 @@ ifeq ($(CONFIG_X86_32),y) ifneq ($(CONFIG_X86_CMPXCHG64),y) lib-y += cmpxchg8b_emu.o atomic64_386_32.o endif - lib-$(CONFIG_X86_USE_3DNOW) += mmx_32.o else obj-y += iomap_copy_64.o lib-y += csum-partial_64.o csum-copy_64.o csum-wrappers_64.o --- a/arch/x86/lib/memcpy_32.c +++ b/arch/x86/lib/memcpy_32.c @@ -7,11 +7,7 @@ __visible void *memcpy(void *to, const void *from, size_t n) { -#if defined(CONFIG_X86_USE_3DNOW) && !defined(CONFIG_FORTIFY_SOURCE) - return __memcpy3d(to, from, n); -#else return __memcpy(to, from, n); -#endif } EXPORT_SYMBOL(memcpy); --- a/arch/x86/lib/mmx_32.c +++ b/arch/x86/lib/mmx_32.c @@ -1,388 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * MMX 3DNow! library helper functions - * - * To do: - * We can use MMX just for prefetch in IRQ's. This may be a win. - * (reported so on K6-III) - * We should use a better code neutral filler for the short jump - * leal ebx. [ebx] is apparently best for K6-2, but Cyrix ?? - * We also want to clobber the filler register so we don't get any - * register forwarding stalls on the filler. - * - * Add *user handling. Checksums are not a win with MMX on any CPU - * tested so far for any MMX solution figured. - * - * 22/09/2000 - Arjan van de Ven - * Improved for non-engineering-sample Athlons - * - */ -#include -#include -#include -#include -#include - -#include -#include - -/* - * Use KFPU_387. MMX instructions are not affected by MXCSR, - * but both AMD and Intel documentation states that even integer MMX - * operations will result in #MF if an exception is pending in FCW. - * - * EMMS is not needed afterwards because, after calling kernel_fpu_end(), - * any subsequent user of the 387 stack will reinitialize it using - * KFPU_387. - */ - -void *_mmx_memcpy(void *to, const void *from, size_t len) -{ - void *p; - int i; - - if (unlikely(in_interrupt())) - return __memcpy(to, from, len); - - p = to; - i = len >> 6; /* len/64 */ - - kernel_fpu_begin_mask(KFPU_387); - - __asm__ __volatile__ ( - "1: prefetch (%0)\n" /* This set is 28 bytes */ - " prefetch 64(%0)\n" - " prefetch 128(%0)\n" - " prefetch 192(%0)\n" - " prefetch 256(%0)\n" - "2: \n" - ".section .fixup, \"ax\"\n" - "3: movw $0x1AEB, 1b\n" /* jmp on 26 bytes */ - " jmp 2b\n" - ".previous\n" - _ASM_EXTABLE(1b, 3b) - : : "r" (from)); - - for ( ; i > 5; i--) { - __asm__ __volatile__ ( - "1: prefetch 320(%0)\n" - "2: movq (%0), %%mm0\n" - " movq 8(%0), %%mm1\n" - " movq 16(%0), %%mm2\n" - " movq 24(%0), %%mm3\n" - " movq %%mm0, (%1)\n" - " movq %%mm1, 8(%1)\n" - " movq %%mm2, 16(%1)\n" - " movq %%mm3, 24(%1)\n" - " movq 32(%0), %%mm0\n" - " movq 40(%0), %%mm1\n" - " movq 48(%0), %%mm2\n" - " movq 56(%0), %%mm3\n" - " movq %%mm0, 32(%1)\n" - " movq %%mm1, 40(%1)\n" - " movq %%mm2, 48(%1)\n" - " movq %%mm3, 56(%1)\n" - ".section .fixup, \"ax\"\n" - "3: movw $0x05EB, 1b\n" /* jmp on 5 bytes */ - " jmp 2b\n" - ".previous\n" - _ASM_EXTABLE(1b, 3b) - : : "r" (from), "r" (to) : "memory"); - - from += 64; - to += 64; - } - - for ( ; i > 0; i--) { - __asm__ __volatile__ ( - " movq (%0), %%mm0\n" - " movq 8(%0), %%mm1\n" - " movq 16(%0), %%mm2\n" - " movq 24(%0), %%mm3\n" - " movq %%mm0, (%1)\n" - " movq %%mm1, 8(%1)\n" - " movq %%mm2, 16(%1)\n" - " movq %%mm3, 24(%1)\n" - " movq 32(%0), %%mm0\n" - " movq 40(%0), %%mm1\n" - " movq 48(%0), %%mm2\n" - " movq 56(%0), %%mm3\n" - " movq %%mm0, 32(%1)\n" - " movq %%mm1, 40(%1)\n" - " movq %%mm2, 48(%1)\n" - " movq %%mm3, 56(%1)\n" - : : "r" (from), "r" (to) : "memory"); - - from += 64; - to += 64; - } - /* - * Now do the tail of the block: - */ - __memcpy(to, from, len & 63); - kernel_fpu_end(); - - return p; -} -EXPORT_SYMBOL(_mmx_memcpy); - -#ifdef CONFIG_MK7 - -/* - * The K7 has streaming cache bypass load/store. The Cyrix III, K6 and - * other MMX using processors do not. - */ - -static void fast_clear_page(void *page) -{ - int i; - - kernel_fpu_begin_mask(KFPU_387); - - __asm__ __volatile__ ( - " pxor %%mm0, %%mm0\n" : : - ); - - for (i = 0; i < 4096/64; i++) { - __asm__ __volatile__ ( - " movntq %%mm0, (%0)\n" - " movntq %%mm0, 8(%0)\n" - " movntq %%mm0, 16(%0)\n" - " movntq %%mm0, 24(%0)\n" - " movntq %%mm0, 32(%0)\n" - " movntq %%mm0, 40(%0)\n" - " movntq %%mm0, 48(%0)\n" - " movntq %%mm0, 56(%0)\n" - : : "r" (page) : "memory"); - page += 64; - } - - /* - * Since movntq is weakly-ordered, a "sfence" is needed to become - * ordered again: - */ - __asm__ __volatile__("sfence\n"::); - - kernel_fpu_end(); -} - -static void fast_copy_page(void *to, void *from) -{ - int i; - - kernel_fpu_begin_mask(KFPU_387); - - /* - * maybe the prefetch stuff can go before the expensive fnsave... - * but that is for later. -AV - */ - __asm__ __volatile__( - "1: prefetch (%0)\n" - " prefetch 64(%0)\n" - " prefetch 128(%0)\n" - " prefetch 192(%0)\n" - " prefetch 256(%0)\n" - "2: \n" - ".section .fixup, \"ax\"\n" - "3: movw $0x1AEB, 1b\n" /* jmp on 26 bytes */ - " jmp 2b\n" - ".previous\n" - _ASM_EXTABLE(1b, 3b) : : "r" (from)); - - for (i = 0; i < (4096-320)/64; i++) { - __asm__ __volatile__ ( - "1: prefetch 320(%0)\n" - "2: movq (%0), %%mm0\n" - " movntq %%mm0, (%1)\n" - " movq 8(%0), %%mm1\n" - " movntq %%mm1, 8(%1)\n" - " movq 16(%0), %%mm2\n" - " movntq %%mm2, 16(%1)\n" - " movq 24(%0), %%mm3\n" - " movntq %%mm3, 24(%1)\n" - " movq 32(%0), %%mm4\n" - " movntq %%mm4, 32(%1)\n" - " movq 40(%0), %%mm5\n" - " movntq %%mm5, 40(%1)\n" - " movq 48(%0), %%mm6\n" - " movntq %%mm6, 48(%1)\n" - " movq 56(%0), %%mm7\n" - " movntq %%mm7, 56(%1)\n" - ".section .fixup, \"ax\"\n" - "3: movw $0x05EB, 1b\n" /* jmp on 5 bytes */ - " jmp 2b\n" - ".previous\n" - _ASM_EXTABLE(1b, 3b) : : "r" (from), "r" (to) : "memory"); - - from += 64; - to += 64; - } - - for (i = (4096-320)/64; i < 4096/64; i++) { - __asm__ __volatile__ ( - "2: movq (%0), %%mm0\n" - " movntq %%mm0, (%1)\n" - " movq 8(%0), %%mm1\n" - " movntq %%mm1, 8(%1)\n" - " movq 16(%0), %%mm2\n" - " movntq %%mm2, 16(%1)\n" - " movq 24(%0), %%mm3\n" - " movntq %%mm3, 24(%1)\n" - " movq 32(%0), %%mm4\n" - " movntq %%mm4, 32(%1)\n" - " movq 40(%0), %%mm5\n" - " movntq %%mm5, 40(%1)\n" - " movq 48(%0), %%mm6\n" - " movntq %%mm6, 48(%1)\n" - " movq 56(%0), %%mm7\n" - " movntq %%mm7, 56(%1)\n" - : : "r" (from), "r" (to) : "memory"); - from += 64; - to += 64; - } - /* - * Since movntq is weakly-ordered, a "sfence" is needed to become - * ordered again: - */ - __asm__ __volatile__("sfence \n"::); - kernel_fpu_end(); -} - -#else /* CONFIG_MK7 */ - -/* - * Generic MMX implementation without K7 specific streaming - */ -static void fast_clear_page(void *page) -{ - int i; - - kernel_fpu_begin_mask(KFPU_387); - - __asm__ __volatile__ ( - " pxor %%mm0, %%mm0\n" : : - ); - - for (i = 0; i < 4096/128; i++) { - __asm__ __volatile__ ( - " movq %%mm0, (%0)\n" - " movq %%mm0, 8(%0)\n" - " movq %%mm0, 16(%0)\n" - " movq %%mm0, 24(%0)\n" - " movq %%mm0, 32(%0)\n" - " movq %%mm0, 40(%0)\n" - " movq %%mm0, 48(%0)\n" - " movq %%mm0, 56(%0)\n" - " movq %%mm0, 64(%0)\n" - " movq %%mm0, 72(%0)\n" - " movq %%mm0, 80(%0)\n" - " movq %%mm0, 88(%0)\n" - " movq %%mm0, 96(%0)\n" - " movq %%mm0, 104(%0)\n" - " movq %%mm0, 112(%0)\n" - " movq %%mm0, 120(%0)\n" - : : "r" (page) : "memory"); - page += 128; - } - - kernel_fpu_end(); -} - -static void fast_copy_page(void *to, void *from) -{ - int i; - - kernel_fpu_begin_mask(KFPU_387); - - __asm__ __volatile__ ( - "1: prefetch (%0)\n" - " prefetch 64(%0)\n" - " prefetch 128(%0)\n" - " prefetch 192(%0)\n" - " prefetch 256(%0)\n" - "2: \n" - ".section .fixup, \"ax\"\n" - "3: movw $0x1AEB, 1b\n" /* jmp on 26 bytes */ - " jmp 2b\n" - ".previous\n" - _ASM_EXTABLE(1b, 3b) : : "r" (from)); - - for (i = 0; i < 4096/64; i++) { - __asm__ __volatile__ ( - "1: prefetch 320(%0)\n" - "2: movq (%0), %%mm0\n" - " movq 8(%0), %%mm1\n" - " movq 16(%0), %%mm2\n" - " movq 24(%0), %%mm3\n" - " movq %%mm0, (%1)\n" - " movq %%mm1, 8(%1)\n" - " movq %%mm2, 16(%1)\n" - " movq %%mm3, 24(%1)\n" - " movq 32(%0), %%mm0\n" - " movq 40(%0), %%mm1\n" - " movq 48(%0), %%mm2\n" - " movq 56(%0), %%mm3\n" - " movq %%mm0, 32(%1)\n" - " movq %%mm1, 40(%1)\n" - " movq %%mm2, 48(%1)\n" - " movq %%mm3, 56(%1)\n" - ".section .fixup, \"ax\"\n" - "3: movw $0x05EB, 1b\n" /* jmp on 5 bytes */ - " jmp 2b\n" - ".previous\n" - _ASM_EXTABLE(1b, 3b) - : : "r" (from), "r" (to) : "memory"); - - from += 64; - to += 64; - } - kernel_fpu_end(); -} - -#endif /* !CONFIG_MK7 */ - -/* - * Favour MMX for page clear and copy: - */ -static void slow_zero_page(void *page) -{ - int d0, d1; - - __asm__ __volatile__( - "cld\n\t" - "rep ; stosl" - - : "=&c" (d0), "=&D" (d1) - :"a" (0), "1" (page), "0" (1024) - :"memory"); -} - -void mmx_clear_page(void *page) -{ - if (unlikely(in_interrupt())) - slow_zero_page(page); - else - fast_clear_page(page); -} -EXPORT_SYMBOL(mmx_clear_page); - -static void slow_copy_page(void *to, void *from) -{ - int d0, d1, d2; - - __asm__ __volatile__( - "cld\n\t" - "rep ; movsl" - : "=&c" (d0), "=&D" (d1), "=&S" (d2) - : "0" (1024), "1" ((long) to), "2" ((long) from) - : "memory"); -} - -void mmx_copy_page(void *to, void *from) -{ - if (unlikely(in_interrupt())) - slow_copy_page(to, from); - else - fast_copy_page(to, from); -} -EXPORT_SYMBOL(mmx_copy_page); --- a/arch/x86/lib/usercopy_32.c +++ b/arch/x86/lib/usercopy_32.c @@ -8,7 +8,6 @@ */ #include #include -#include #include #ifdef CONFIG_X86_INTEL_USERCOPY --- a/tools/arch/x86/include/asm/required-features.h +++ b/tools/arch/x86/include/asm/required-features.h @@ -35,11 +35,7 @@ # define NEED_CMOV 0 #endif -#ifdef CONFIG_X86_USE_3DNOW -# define NEED_3DNOW (1<<(X86_FEATURE_3DNOW & 31)) -#else # define NEED_3DNOW 0 -#endif #if defined(CONFIG_X86_P6_NOP) || defined(CONFIG_X86_64) # define NEED_NOPL (1<<(X86_FEATURE_NOPL & 31))