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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 73CF1C43381 for ; Mon, 1 Apr 2019 17:44:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 421F620896 for ; Mon, 1 Apr 2019 17:44:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ah9q799H" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388032AbfDARog (ORCPT ); Mon, 1 Apr 2019 13:44:36 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:53813 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731020AbfDARof (ORCPT ); Mon, 1 Apr 2019 13:44:35 -0400 Received: by mail-wm1-f67.google.com with SMTP id q16so305566wmj.3 for ; Mon, 01 Apr 2019 10:44:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=C5Z+ZbojR8u61jx7QLYGdsSJ+zSY1pyusZunuxUJras=; b=ah9q799HTT/VJZJ8zvV566ZT6PUgJYQMQwE8h68d4sTIAUnefzPba0JUl87JIiqIak oBX1jooenbUF1gcB9Qq2ahtNaahlRHjVvLqr8Zr3VZKPpdRBQ2aG7v+qfLrWoIEsKLcZ ZzH8LZlP2Ii4Dawmm+YlE/fG4vHN9yYtAxy9k0CzWaUsxbF7kyH6zXC7KvobdrYC4Oxz zYYz0F/0WCkNK5FuFstFdtdZXHvH0/lKXC6N25q6vcDguxl1H06RniqtQ4q3aQjZea2S 9YGeIfBy7saDfYhuruGoO+ZejEdVOsiXU66g1VNEHhShbqWKSW6DaXukmcg9W+9uwJc0 oqlA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=C5Z+ZbojR8u61jx7QLYGdsSJ+zSY1pyusZunuxUJras=; b=tqwDH56LLbfBQzeidRWwYu6Cs6HdaDiJYRv3GIFAcHTrBE0y7/yO/LItjFivUhbCDu oXSZTQaNC/7jFbWJtAMsB1oFJ8Sh23bhZTAAeX0cDOTdyvYfjMG9LYTHAHkm6O9s91h+ wpAEVay7SWG36pPdNzazr1tLOeebq7m+hb9VKApnbXqD6j00GtMvO8HMZrqYNfip1qq4 y0Srcr/JglFCpktLqkJG1Cnvtsa9jeqAqUvbSoXYs7+oBwc1utY7HPmlrhSk+VBNyQWL LlatyszUTE+cPpwTfcI5aYRIDqwFVBOIkCsos3zB6hyTM1RnNigO+hhR6eCoYThAnfLp wQ8g== X-Gm-Message-State: APjAAAUqck/JAMkOV4w9GzNQFzJBfbKfweQ/0rHyb1RVRoBZJXryxQho AwPjljcRoE9swMMoUcRDfIS4oIgm X-Google-Smtp-Source: APXvYqyl1xk+uTWD92DIZ/fp2+5o3L455tD6kTSkPIyfzSVFDrmFQAm2daMUL7Te6sV14vdtNHTVTA== X-Received: by 2002:a1c:f312:: with SMTP id q18mr500833wmq.96.1554140672843; Mon, 01 Apr 2019 10:44:32 -0700 (PDT) Received: from ogabbay-VM.habana-labs.com ([31.154.190.6]) by smtp.gmail.com with ESMTPSA id i18sm11892955wrm.7.2019.04.01.10.44.31 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 01 Apr 2019 10:44:32 -0700 (PDT) From: Oded Gabbay To: linux-kernel@vger.kernel.org Cc: gregkh@linuxfoundation.org Subject: [PATCH] habanalabs: prevent CPU soft lockup on Palladium Date: Mon, 1 Apr 2019 20:44:30 +0300 Message-Id: <20190401174430.15553-1-oded.gabbay@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Unmapping ptes in the device MMU on Palladium can take a long time, which can cause a kernel BUG of CPU soft lockup. This patch minimize the chances for this bug by sleeping a little between unmapping ptes. Signed-off-by: Oded Gabbay --- drivers/misc/habanalabs/memory.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/misc/habanalabs/memory.c b/drivers/misc/habanalabs/memory.c index 39788b1cf8d0..e9e163545584 100644 --- a/drivers/misc/habanalabs/memory.c +++ b/drivers/misc/habanalabs/memory.c @@ -1046,10 +1046,17 @@ static int unmap_device_va(struct hl_ctx *ctx, u64 vaddr) mutex_lock(&ctx->mmu_lock); - for (i = 0 ; i < phys_pg_pack->npages ; i++, next_vaddr += page_size) + for (i = 0 ; i < phys_pg_pack->npages ; i++, next_vaddr += page_size) { if (hl_mmu_unmap(ctx, next_vaddr, page_size)) dev_warn_ratelimited(hdev->dev, - "unmap failed for vaddr: 0x%llx\n", next_vaddr); + "unmap failed for vaddr: 0x%llx\n", next_vaddr); + + /* unmapping on Palladium can be really long, so avoid a CPU + * soft lockup bug by sleeping a little between unmapping pages + */ + if (hdev->pldm) + usleep_range(500, 1000); + } hdev->asic_funcs->mmu_invalidate_cache(hdev, true); -- 2.17.1