From patchwork Sun Sep 1 15:40:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fredrik Noring X-Patchwork-Id: 11125331 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 ED82F16B1 for ; Sun, 1 Sep 2019 15:46:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D517821897 for ; Sun, 1 Sep 2019 15:46:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729146AbfIAPq5 (ORCPT ); Sun, 1 Sep 2019 11:46:57 -0400 Received: from pio-pvt-msa1.bahnhof.se ([79.136.2.40]:56632 "EHLO pio-pvt-msa1.bahnhof.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728980AbfIAPq5 (ORCPT ); Sun, 1 Sep 2019 11:46:57 -0400 Received: from localhost (localhost [127.0.0.1]) by pio-pvt-msa1.bahnhof.se (Postfix) with ESMTP id 6405C3F73E for ; Sun, 1 Sep 2019 17:40:13 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at bahnhof.se X-Spam-Flag: NO X-Spam-Score: -1.899 X-Spam-Level: X-Spam-Status: No, score=-1.899 tagged_above=-999 required=6.31 tests=[BAYES_00=-1.9, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no Received: from pio-pvt-msa1.bahnhof.se ([127.0.0.1]) by localhost (pio-pvt-msa1.bahnhof.se [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id cMHQ580nK6w4 for ; Sun, 1 Sep 2019 17:40:12 +0200 (CEST) Received: from localhost (h-41-252.A163.priv.bahnhof.se [46.59.41.252]) (Authenticated sender: mb547485) by pio-pvt-msa1.bahnhof.se (Postfix) with ESMTPA id 6A5503F708 for ; Sun, 1 Sep 2019 17:40:12 +0200 (CEST) Date: Sun, 1 Sep 2019 17:40:12 +0200 From: Fredrik Noring To: linux-mips@vger.kernel.org Subject: [PATCH 011/120] MIPS: R5900: Avoid pipeline hazard with the TLBP instruction Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On the R5900, the TLBP instruction must be immediately followed by an ERET or a SYNC.P instruction[1]. References: [1] "TX System RISC TX79 Core Architecture" manual, revision 2.0, Toshiba Corporation, p. C-37, https://wiki.qemu.org/File:C790.pdf Signed-off-by: Fredrik Noring --- arch/mips/mm/tlbex.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index 82136c346885..0519e2eafbb8 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -489,6 +489,19 @@ static void __maybe_unused build_tlb_probe_entry(u32 **p) uasm_i_tlbp(p); break; + case CPU_R5900: + /* + * On the R5900, the TLBWP instruction must be immediately + * followed by an ERET or a SYNC.P instruction. + */ + uasm_i_tlbp(p); + uasm_i_syncp(p); + uasm_i_nop(p); + uasm_i_nop(p); + uasm_i_nop(p); + uasm_i_nop(p); + break; + default: uasm_i_tlbp(p); break;