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=-8.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,T_DKIM_INVALID,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 E7B52ECE560 for ; Mon, 17 Sep 2018 15:38:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A28F920883 for ; Mon, 17 Sep 2018 15:38:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="B0lO/Jol" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A28F920883 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de 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 S1729451AbeIQVGq (ORCPT ); Mon, 17 Sep 2018 17:06:46 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:59948 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727858AbeIQVGp (ORCPT ); Mon, 17 Sep 2018 17:06:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=qix1iJUyrJdPI4v1IFPLfBzhDQt7WpL1CLDLBWJoNxI=; b=B0lO/JolgUFCIEBvIXtM8q1YC fnXTT0LtCCWwijPzxfi0leAbhpShRI/AnsgWqriKZi8hLnzTKFj9ejP/6lQT6PcjAGwAbC5KxWN8y BWICaSVg4c7ytfPjOlvvgf2JukkUU2fSIGXH11QuwXECrRk8cF621Mb3UBp3Um0oTKRBz4YvxJSZC MVkhGRo9doIEjjiPAukp8A7AS7BtwOLT85uwFyND/4mDWtqqjW9kpCVfJKFXHWoHsGj3FLui5B06t 0H4+6Sb7uEhMC7w8J2EzIR1fdaRkNCJdfX4zFtg5ylLXAHtKiQh20v25//RHZ5LfMvGmSHuA5HHyT T/OTa9lvg==; Received: from 089144198037.atnat0007.highway.a1.net ([89.144.198.37] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1g1vbi-0006AZ-Cb; Mon, 17 Sep 2018 15:38:38 +0000 From: Christoph Hellwig To: Will Deacon , Catalin Marinas , Robin Murphy , Konrad Rzeszutek Wilk Cc: linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/9] swiotlb: do not panic on mapping failures Date: Mon, 17 Sep 2018 17:38:20 +0200 Message-Id: <20180917153826.28052-4-hch@lst.de> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180917153826.28052-1-hch@lst.de> References: <20180917153826.28052-1-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org All properly written drivers now have error handling in the dma_map_single / dma_map_page callers. As swiotlb_tbl_map_single already prints a useful warning when running out of swiotlb pool swace we can also remove swiotlb_full entirely as it serves no purpose now. Signed-off-by: Christoph Hellwig --- kernel/dma/swiotlb.c | 33 +-------------------------------- 1 file changed, 1 insertion(+), 32 deletions(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 26d3af52956f..69bf305ee5f8 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -761,34 +761,6 @@ static bool swiotlb_free_buffer(struct device *dev, size_t size, return true; } -static void -swiotlb_full(struct device *dev, size_t size, enum dma_data_direction dir, - int do_panic) -{ - if (swiotlb_force == SWIOTLB_NO_FORCE) - return; - - /* - * Ran out of IOMMU space for this operation. This is very bad. - * Unfortunately the drivers cannot handle this operation properly. - * unless they check for dma_mapping_error (most don't) - * When the mapping is small enough return a static buffer to limit - * the damage, or panic when the transfer is too big. - */ - dev_err_ratelimited(dev, "DMA: Out of SW-IOMMU space for %zu bytes\n", - size); - - if (size <= io_tlb_overflow || !do_panic) - return; - - if (dir == DMA_BIDIRECTIONAL) - panic("DMA: Random memory could be DMA accessed\n"); - if (dir == DMA_FROM_DEVICE) - panic("DMA: Random memory could be DMA written\n"); - if (dir == DMA_TO_DEVICE) - panic("DMA: Random memory could be DMA read\n"); -} - /* * Map a single buffer of the indicated size for DMA in streaming mode. The * physical address to use is returned. @@ -817,10 +789,8 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, /* Oh well, have to allocate and map a bounce buffer. */ map = map_single(dev, phys, size, dir, attrs); - if (map == SWIOTLB_MAP_ERROR) { - swiotlb_full(dev, size, dir, 1); + if (map == SWIOTLB_MAP_ERROR) return __phys_to_dma(dev, io_tlb_overflow_buffer); - } dev_addr = __phys_to_dma(dev, map); @@ -948,7 +918,6 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems, if (map == SWIOTLB_MAP_ERROR) { /* Don't panic here, we expect map_sg users to do proper error handling. */ - swiotlb_full(hwdev, sg->length, dir, 0); attrs |= DMA_ATTR_SKIP_CPU_SYNC; swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir, attrs); -- 2.18.0