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 BA6E2C43603 for ; Wed, 11 Dec 2019 15:42:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 911FE2073B for ; Wed, 11 Dec 2019 15:42:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576078948; bh=UNiTk+f8fE9Yz8lhsQdrFBLP5bg3jUY8qkUscn+BsVg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VISAdi72AVsJHP9L0DgxA5WBMV6eh0Xvk0Ttumu8rndNvB0KkGPg/jP5cIRuZPjAQ KeqPrn1w3H7VqXz2+fn6c0J2Woge80PLp8BbVFowl/NOk6BgA3cUND0Xo1jM52+VaK rcRDI8Y8nq8GxWWQc6hqFYxm92n3pI0ABXdEjHXg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387456AbfLKP1n (ORCPT ); Wed, 11 Dec 2019 10:27:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:32992 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733063AbfLKP1X (ORCPT ); Wed, 11 Dec 2019 10:27:23 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 21EB224671; Wed, 11 Dec 2019 15:27:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576078042; bh=UNiTk+f8fE9Yz8lhsQdrFBLP5bg3jUY8qkUscn+BsVg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=byX56x9yKEvGMaPN82OMwHr52hwGn3bwCJqFi4JBE1rPoupLDp4p3clHcZZ6tgRbx BytbWSDZu/+pIkltDbkZ+B7aTdDZsmHwo7jLIQ+o0tgJK8f6WRy5d2sW/PDkq7Tztw ypw0VwrmTrH1pAgtMI65mGXEfUyJuF80MOn6n6vA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kars de Jong , Finn Thain , "Martin K . Petersen" , Sasha Levin , linux-scsi@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 36/79] scsi: zorro_esp: Limit DMA transfers to 65536 bytes (except on Fastlane) Date: Wed, 11 Dec 2019 10:26:00 -0500 Message-Id: <20191211152643.23056-36-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191211152643.23056-1-sashal@kernel.org> References: <20191211152643.23056-1-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: Kars de Jong [ Upstream commit 02f7e9f351a9de95577eafdc3bd413ed1c3b589f ] When using this driver on a Blizzard 1260, there were failures whenever DMA transfers from the SCSI bus to memory of 65535 bytes were followed by a DMA transfer of 1 byte. This caused the byte at offset 65535 to be overwritten with 0xff. The Blizzard hardware can't handle single byte DMA transfers. Besides this issue, limiting the DMA length to something that is not a multiple of the page size is very inefficient on most file systems. It seems this limit was chosen because the DMA transfer counter of the ESP by default is 16 bits wide, thus limiting the length to 65535 bytes. However, the value 0 means 65536 bytes, which is handled by the ESP and the Blizzard just fine. It is also the default maximum used by esp_scsi when drivers don't provide their own dma_length_limit() function. The limit of 65536 bytes can be used by all boards except the Fastlane. The old driver used a limit of 65532 bytes (0xfffc), which is reintroduced in this patch. Fixes: b7ded0e8b0d1 ("scsi: zorro_esp: Limit DMA transfers to 65535 bytes") Link: https://lore.kernel.org/r/20191112175523.23145-1-jongk@linux-m68k.org Signed-off-by: Kars de Jong Reviewed-by: Finn Thain Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/zorro_esp.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/zorro_esp.c b/drivers/scsi/zorro_esp.c index be79127db5946..6a5b547eae590 100644 --- a/drivers/scsi/zorro_esp.c +++ b/drivers/scsi/zorro_esp.c @@ -245,7 +245,14 @@ static int fastlane_esp_irq_pending(struct esp *esp) static u32 zorro_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len) { - return dma_len > 0xFFFF ? 0xFFFF : dma_len; + return dma_len > (1U << 16) ? (1U << 16) : dma_len; +} + +static u32 fastlane_esp_dma_length_limit(struct esp *esp, u32 dma_addr, + u32 dma_len) +{ + /* The old driver used 0xfffc as limit, so do that here too */ + return dma_len > 0xfffc ? 0xfffc : dma_len; } static void zorro_esp_reset_dma(struct esp *esp) @@ -818,7 +825,7 @@ static const struct esp_driver_ops fastlane_esp_ops = { .unmap_single = zorro_esp_unmap_single, .unmap_sg = zorro_esp_unmap_sg, .irq_pending = fastlane_esp_irq_pending, - .dma_length_limit = zorro_esp_dma_length_limit, + .dma_length_limit = fastlane_esp_dma_length_limit, .reset_dma = zorro_esp_reset_dma, .dma_drain = zorro_esp_dma_drain, .dma_invalidate = fastlane_esp_dma_invalidate, -- 2.20.1