From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x242.google.com (mail-pg0-x242.google.com [IPv6:2607:f8b0:400e:c05::242]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40CNRd3kGnzF1wn for ; Sat, 31 Mar 2018 00:55:24 +1100 (AEDT) Received: by mail-pg0-x242.google.com with SMTP id y63so5094147pgy.12 for ; Fri, 30 Mar 2018 06:55:24 -0700 (PDT) From: Balbir Singh To: linuxppc-dev@lists.ozlabs.org Cc: npiggin@gmail.com, mpe@ellerman.id.au, mahesh@linux.vnet.ibm.com, oohall@gmail.com, Balbir Singh Subject: [RFC 0/3] Add support for memcpy_mcsafe Date: Sat, 31 Mar 2018 00:55:09 +1100 Message-Id: <20180330135512.23760-1-bsingharora@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , memcpy_mcsafe() is an API currently used by the pmem subsystem to convert errors while doing a memcpy (machine check exception errors) to a return value. This patchset consists of three patches 1. The first patch is a bug fix to handle machine check errors correctly while walking the page tables in kernel mode, due to huge pmd/pud sizes 2. The second patch adds memcpy_mcsafe() support, this is largely derived from existing code 3. The third patch registers for callbacks on machine check exceptions and in them uses specialized knowledge of the type of page to decide whether to handle the MCE as is or to return to a fixup address present in memcpy_mcsafe(). If a fixup address is used, then we return an error value of -EFAULT to the caller. Testing A large part of the testing was done under a simulator by selectively inserting machine check exceptions in a test driver doing memcpy_mcsafe via ioctls. Balbir Singh (3): powerpc/mce: Bug fixes for MCE handling in kernel space powerpc/memcpy: Add memcpy_mcsafe for pmem powerpc/mce: Handle memcpy_mcsafe arch/powerpc/include/asm/mce.h | 3 +- arch/powerpc/include/asm/string.h | 2 + arch/powerpc/kernel/mce.c | 76 +++++++++++- arch/powerpc/kernel/mce_power.c | 17 +-- arch/powerpc/lib/Makefile | 2 +- arch/powerpc/lib/memcpy_mcsafe_64.S | 225 ++++++++++++++++++++++++++++++++++++ 6 files changed, 314 insertions(+), 11 deletions(-) create mode 100644 arch/powerpc/lib/memcpy_mcsafe_64.S -- 2.13.6