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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 F10F8C43143 for ; Tue, 2 Oct 2018 13:27:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B5D422089A for ; Tue, 2 Oct 2018 13:27:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B5D422089A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728485AbeJBUKl (ORCPT ); Tue, 2 Oct 2018 16:10:41 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60242 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728384AbeJBUKk (ORCPT ); Tue, 2 Oct 2018 16:10:40 -0400 Received: from localhost (24-104-73-23-ip-static.hfc.comcastbusiness.net [24.104.73.23]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id DD9DDB2F; Tue, 2 Oct 2018 13:27:18 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexey Kardashevskiy , Michael Ellerman , Sasha Levin Subject: [PATCH 4.18 053/228] powerpc/powernv/ioda2: Reduce upper limit for DMA window size Date: Tue, 2 Oct 2018 06:22:30 -0700 Message-Id: <20181002132502.776650588@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181002132459.032960735@linuxfoundation.org> References: <20181002132459.032960735@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexey Kardashevskiy [ Upstream commit d3d4ffaae439981e1e441ebb125aa3588627c5d8 ] We use PHB in mode1 which uses bit 59 to select a correct DMA window. However there is mode2 which uses bits 59:55 and allows up to 32 DMA windows per a PE. Even though documentation does not clearly specify that, it seems that the actual hardware does not support bits 59:55 even in mode1, in other words we can create a window as big as 1<<58 but DMA simply won't work. This reduces the upper limit from 59 to 55 bits to let the userspace know about the hardware limits. Fixes: 7aafac11e3 "powerpc/powernv/ioda2: Gracefully fail if too many TCE levels requested" Signed-off-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/platforms/powernv/pci-ioda.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -2841,7 +2841,7 @@ static long pnv_pci_ioda2_table_alloc_pa level_shift = entries_shift + 3; level_shift = max_t(unsigned, level_shift, PAGE_SHIFT); - if ((level_shift - 3) * levels + page_shift >= 60) + if ((level_shift - 3) * levels + page_shift >= 55) return -EINVAL; /* Allocate TCE table */