From patchwork Sat Aug 1 17:22:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 11696171 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 90B2914DD for ; Sat, 1 Aug 2020 17:38:57 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 778E52065E for ; Sat, 1 Aug 2020 17:38:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 778E52065E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 42055119BC048; Sat, 1 Aug 2020 10:38:57 -0700 (PDT) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=134.134.136.31; helo=mga06.intel.com; envelope-from=dan.j.williams@intel.com; receiver= Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id C06A71188C065 for ; Sat, 1 Aug 2020 10:38:55 -0700 (PDT) IronPort-SDR: qBOW5S2vt82R9Fy+jS/LEwgZPT3h6Ve9wjaRrLK8+g3SbjKQisbKGHyj9qYLy247glM6f3+NM7 w+iLRYLrMplg== X-IronPort-AV: E=McAfee;i="6000,8403,9699"; a="213481442" X-IronPort-AV: E=Sophos;i="5.75,423,1589266800"; d="scan'208";a="213481442" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Aug 2020 10:38:55 -0700 IronPort-SDR: KRjjdqdzFj6+0PzdZWkJsUEcbjVt3ZTshu8heTogL8MViDiBwCfEOXZz4d+BLX+oJd/bX90qKU M+b1xREghqEg== X-IronPort-AV: E=Sophos;i="5.75,423,1589266800"; d="scan'208";a="395632580" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Aug 2020 10:38:54 -0700 Subject: [PATCH v8 0/2] Renovate memcpy_mcsafe with copy_mc_to_{user, kernel} From: Dan Williams To: tglx@linutronix.de, mingo@redhat.com, vishal.l.verma@intel.com Date: Sat, 01 Aug 2020 10:22:36 -0700 Message-ID: <159630255616.3143511.18110575960499749012.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Message-ID-Hash: DYU35DF66FV4RB3HIAZJBFLGHMGMJ5Q3 X-Message-ID-Hash: DYU35DF66FV4RB3HIAZJBFLGHMGMJ5Q3 X-MailFrom: dan.j.williams@intel.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header CC: Tony Luck , Peter Zijlstra , Linus Torvalds , Alexander Viro , Borislav Petkov , stable@vger.kernel.org, x86@kernel.org, "H. Peter Anvin" , Andy Lutomirski , Paul Mackerras , Benjamin Herrenschmidt , Erwin Tsaur , Michael Ellerman , Mikulas Patocka , Arnaldo Carvalho de Melo , linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Changes since v7 [1]: - Rebased on v5.8-rc5 to resolve a conflict with commit eb25de276505 ("tools arch: Update arch/x86/lib/memcpy_64.S copy used in 'perf bench mem memcpy'") [1]: http://lore.kernel.org/r/159408043801.2272533.17485467640602344900.stgit@dwillia2-desk3.amr.corp.intel.com --- Vishal, since this patch set has experienced unprecedented silence from x86 folks I expect you will need to send it to Linus directly during the merge window. It merges cleanly with recent -next. Thomas, Ingo, Boris, please chime in to save Vishal from that awkwardness. I am only going to be sporadically online for the next few weeks. --- The primary motivation to go touch memcpy_mcsafe() is that the existing benefit of doing slow and careful copies is obviated on newer CPUs. That fact solves the problem of needing to detect machine-check recovery capability. Now the old "mcsafe_key" opt-in to careful copying can be made an opt-out from the default fast copy implementation. The discussion with Linus further made clear that this facility had already lost its x86-machine-check specificity starting with commit 2c89130a56a ("x86/asm/memcpy_mcsafe: Add write-protection-fault handling"). The new changes to not require a "careful copy" further de-emphasizes the role that x86-MCA plays in the implementation to just one more source of recoverable trap during the operation. With the above realizations the name "mcsafe" is no longer accurate and copy_safe() is proposed as its replacement. x86 grows a copy_safe_fast() implementation as a default implementation that is independent of detecting the presence of x86-MCA. --- Dan Williams (2): x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user,kernel}() x86/copy_mc: Introduce copy_mc_generic() arch/powerpc/Kconfig | 2 arch/powerpc/include/asm/string.h | 2 arch/powerpc/include/asm/uaccess.h | 40 +++-- arch/powerpc/lib/Makefile | 2 arch/powerpc/lib/copy_mc_64.S | 4 arch/x86/Kconfig | 2 arch/x86/Kconfig.debug | 2 arch/x86/include/asm/copy_mc_test.h | 75 +++++++++ arch/x86/include/asm/mcsafe_test.h | 75 --------- arch/x86/include/asm/string_64.h | 32 ---- arch/x86/include/asm/uaccess.h | 21 +++ arch/x86/include/asm/uaccess_64.h | 20 -- arch/x86/kernel/cpu/mce/core.c | 8 - arch/x86/kernel/quirks.c | 9 - arch/x86/lib/Makefile | 1 arch/x86/lib/copy_mc.c | 64 ++++++++ arch/x86/lib/copy_mc_64.S | 165 ++++++++++++++++++++ arch/x86/lib/memcpy_64.S | 115 -------------- arch/x86/lib/usercopy_64.c | 21 --- drivers/md/dm-writecache.c | 15 +- drivers/nvdimm/claim.c | 2 drivers/nvdimm/pmem.c | 6 - include/linux/string.h | 9 - include/linux/uaccess.h | 9 + include/linux/uio.h | 10 + lib/Kconfig | 7 + lib/iov_iter.c | 43 +++-- tools/arch/x86/include/asm/mcsafe_test.h | 13 -- tools/arch/x86/lib/memcpy_64.S | 115 -------------- tools/objtool/check.c | 5 - tools/perf/bench/Build | 1 tools/perf/bench/mem-memcpy-x86-64-lib.c | 24 --- tools/testing/nvdimm/test/nfit.c | 48 +++--- .../testing/selftests/powerpc/copyloops/.gitignore | 2 tools/testing/selftests/powerpc/copyloops/Makefile | 6 - .../selftests/powerpc/copyloops/copy_mc_64.S | 1 .../selftests/powerpc/copyloops/memcpy_mcsafe_64.S | 1 37 files changed, 451 insertions(+), 526 deletions(-) rename arch/powerpc/lib/{memcpy_mcsafe_64.S => copy_mc_64.S} (98%) create mode 100644 arch/x86/include/asm/copy_mc_test.h delete mode 100644 arch/x86/include/asm/mcsafe_test.h create mode 100644 arch/x86/lib/copy_mc.c create mode 100644 arch/x86/lib/copy_mc_64.S delete mode 100644 tools/arch/x86/include/asm/mcsafe_test.h delete mode 100644 tools/perf/bench/mem-memcpy-x86-64-lib.c create mode 120000 tools/testing/selftests/powerpc/copyloops/copy_mc_64.S delete mode 120000 tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S base-commit: 11ba468877bb23f28956a35e896356252d63c983