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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 86802C04E87 for ; Mon, 20 May 2019 01:29:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5EEE420815 for ; Mon, 20 May 2019 01:29:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729901AbfETB31 (ORCPT ); Sun, 19 May 2019 21:29:27 -0400 Received: from 59-120-53-16.HINET-IP.hinet.net ([59.120.53.16]:22374 "EHLO ATCSQR.andestech.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726741AbfETB31 (ORCPT ); Sun, 19 May 2019 21:29:27 -0400 X-Greylist: delayed 471 seconds by postgrey-1.27 at vger.kernel.org; Sun, 19 May 2019 21:29:26 EDT Received: from ATCSQR.andestech.com (localhost [127.0.0.2] (may be forged)) by ATCSQR.andestech.com with ESMTP id x4K1GmAg045473; Mon, 20 May 2019 09:16:48 +0800 (GMT-8) (envelope-from vincentc@andestech.com) Received: from mail.andestech.com (atcpcs16.andestech.com [10.0.1.222]) by ATCSQR.andestech.com with ESMTP id x4K1GZ9r045438; Mon, 20 May 2019 09:16:35 +0800 (GMT-8) (envelope-from vincentc@andestech.com) Received: from atcsqa06.andestech.com (10.0.15.65) by ATCPCS16.andestech.com (10.0.1.222) with Microsoft SMTP Server id 14.3.123.3; Mon, 20 May 2019 09:21:18 +0800 From: Vincent Chen To: , , , , , CC: Subject: [PATCH 0/2] nds32: Prevent FPU emulator from incorrectly modifying IEX status Date: Mon, 20 May 2019 09:21:11 +0800 Message-ID: <1558315273-2795-1-git-send-email-vincentc@andestech.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.0.15.65] X-DNSRBL: X-MAIL: ATCSQR.andestech.com x4K1GZ9r045438 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order for kernel to capture each denormalized output, the UDF trapping enable bit is always raised in $fpcsr. Because underflow case will issue not an underflow exception but also an inexact exception, it causes that the IEX, IEX cumulative exception, flag in $fpcsr to be raised in each denormalized output handling. To make the emulation transparent to the user, the emulator needs to clear the IEX flag in $fpcsr if the result is a denormalized number. However, if the IEX flag has been raised before this floating point emulation, this cleanup may be incorrect. To avoid the IEX flags in $fpcsr be raised in each denormalized output handling, the 1st patch always enable IEX trap to fix this issue. The existing floating point emulations is only available for floating instruction that possibly issue denormalized input and underflow exceptions. These existing FPU emulations are not sufficient when IEx Trap is enabled because some floating point instructions only issue inexact exception. The 2nd patch adds the emulations of such floating point instructions. Vincent Chen (2): nds32: enable IEX trap too when kernel supports denormalized output nds32: add new emulations for floating point instruction arch/nds32/include/asm/bitfield.h | 2 +- arch/nds32/include/asm/fpu.h | 2 +- arch/nds32/include/asm/fpuemu.h | 12 +++++ arch/nds32/include/asm/syscalls.h | 2 +- arch/nds32/include/uapi/asm/fp_udfiex_crtl.h | 16 +++++++ arch/nds32/include/uapi/asm/sigcontext.h | 24 ++++++++--- arch/nds32/include/uapi/asm/udftrap.h | 13 ------ arch/nds32/include/uapi/asm/unistd.h | 4 +- arch/nds32/kernel/fpu.c | 15 +++---- arch/nds32/kernel/sys_nds32.c | 26 ++++++----- arch/nds32/math-emu/Makefile | 5 ++- arch/nds32/math-emu/fd2si.c | 30 +++++++++++++ arch/nds32/math-emu/fd2siz.c | 30 +++++++++++++ arch/nds32/math-emu/fd2ui.c | 30 +++++++++++++ arch/nds32/math-emu/fd2uiz.c | 30 +++++++++++++ arch/nds32/math-emu/fpuemu.c | 57 ++++++++++++++++++++++++-- arch/nds32/math-emu/fs2si.c | 29 +++++++++++++ arch/nds32/math-emu/fs2siz.c | 29 +++++++++++++ arch/nds32/math-emu/fs2ui.c | 29 +++++++++++++ arch/nds32/math-emu/fs2uiz.c | 30 +++++++++++++ arch/nds32/math-emu/fsi2d.c | 22 ++++++++++ arch/nds32/math-emu/fsi2s.c | 22 ++++++++++ arch/nds32/math-emu/fui2d.c | 22 ++++++++++ arch/nds32/math-emu/fui2s.c | 22 ++++++++++ 24 files changed, 452 insertions(+), 51 deletions(-) create mode 100644 arch/nds32/include/uapi/asm/fp_udfiex_crtl.h delete mode 100644 arch/nds32/include/uapi/asm/udftrap.h create mode 100644 arch/nds32/math-emu/fd2si.c create mode 100644 arch/nds32/math-emu/fd2siz.c create mode 100644 arch/nds32/math-emu/fd2ui.c create mode 100644 arch/nds32/math-emu/fd2uiz.c create mode 100644 arch/nds32/math-emu/fs2si.c create mode 100644 arch/nds32/math-emu/fs2siz.c create mode 100644 arch/nds32/math-emu/fs2ui.c create mode 100644 arch/nds32/math-emu/fs2uiz.c create mode 100644 arch/nds32/math-emu/fsi2d.c create mode 100644 arch/nds32/math-emu/fsi2s.c create mode 100644 arch/nds32/math-emu/fui2d.c create mode 100644 arch/nds32/math-emu/fui2s.c