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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 B781AC432C3 for ; Sat, 16 Nov 2019 16:23:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E72021479 for ; Sat, 16 Nov 2019 16:23:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573921405; bh=sgtYBds0vlLgYVSZg75gyqmnkTu5AZWC7qxCtXuwRSU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NVuujXjU2UG+3WxZo3BU9zr65+6LhHiyh8ylTis/7pyo87tBAeRN460cg0EE0MMr4 +l+CFhrV5934gBrkLyKHxx81jNL5w175D40O7mUPlxTcqp2bWRVdhD6JS1HrrsoVnF czYZRLMH9A+gKzotd8sD3O+m8q8JWLiX3x9S84hE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728526AbfKPPm5 (ORCPT ); Sat, 16 Nov 2019 10:42:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:46648 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728485AbfKPPmv (ORCPT ); Sat, 16 Nov 2019 10:42:51 -0500 Received: from sasha-vm.mshome.net (unknown [50.234.116.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C39B420733; Sat, 16 Nov 2019 15:42:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573918971; bh=sgtYBds0vlLgYVSZg75gyqmnkTu5AZWC7qxCtXuwRSU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ehl8uc5HXzzkhqib2b5a6Ok3+AHhCerbVuEIeaPkqtm1iCDAfLrYoi4A4k1CIBvPz XSI9UphBFB2TkD0zb7hgVXqc2H6kEdKj7kuv+cdaAZ1srl/O7oiIuR/2Bs7cLIbQvv AbW685RxwhSDYnQe/kd9UswjfU6HVkfxBDU5PmGU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Christoph Hellwig , Robin Murphy , Sasha Levin , iommu@lists.linux-foundation.org Subject: [PATCH AUTOSEL 4.19 086/237] swiotlb: do not panic on mapping failures Date: Sat, 16 Nov 2019 10:38:41 -0500 Message-Id: <20191116154113.7417-86-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191116154113.7417-1-sashal@kernel.org> References: <20191116154113.7417-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Christoph Hellwig [ Upstream commit 8088546832aa2c0d8f99dd56edf6384f8a9b63b3 ] 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 space we can also remove swiotlb_full entirely as it serves no purpose now. Signed-off-by: Christoph Hellwig Reviewed-by: Robin Murphy Signed-off-by: Sasha Levin --- 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 4f8a6dbf0b609..2a8c41f12d450 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); @@ -954,7 +924,6 @@ 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); -- 2.20.1