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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 DCA82C43331 for ; Tue, 24 Mar 2020 14:42:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD8712074D for ; Tue, 24 Mar 2020 14:42:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AzQIOrFx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727453AbgCXOmQ (ORCPT ); Tue, 24 Mar 2020 10:42:16 -0400 Received: from mail-oi1-f195.google.com ([209.85.167.195]:40701 "EHLO mail-oi1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727498AbgCXOmQ (ORCPT ); Tue, 24 Mar 2020 10:42:16 -0400 Received: by mail-oi1-f195.google.com with SMTP id y71so18633313oia.7 for ; Tue, 24 Mar 2020 07:42:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=fuBgcWTbVSrv8HEBde2Et7610CB72XSqrA2KMltlUXE=; b=AzQIOrFx2YY97DhTgAO5C2cEaMv9IRIpmOTUQVoWnxMAVYu1NHlLa1XhHqIuNvYLvB mv22040q/kVxaRHmxturFPptIpWs7AukVaPpuU2vkxCbXJZrOLIVRVKYFJUiDIVVdKnN OfVxSrd/TeB6kznKq57TB73qoEvKi7Zqqs1hsfUsbEZbETJ3Zc2rt7w5aDQjQ0eokliE T70X244sXZ17AgcV2kw5fbOsE3TkjhR9w4rADn+QW17lZobG5DidcgA00QxmG/Tr0f0y wXzbz9b2wXApae7zTXtZyyH6K0Cwt64zrgMOsn4TylYw1IKqa9+DT5EKCXg4ehOjybuy hMLQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=fuBgcWTbVSrv8HEBde2Et7610CB72XSqrA2KMltlUXE=; b=U76XArxltfLaGctPyuOjwaPi0oVWvXT+8n2achBQGQ2jgcCQ/M1/Th1PBlpWTeSVeG CbX2OJuJFkgvbLHdYjjUCHSp1nfqWXcJ7QoAjuhiYyA8E+AYEnCZejCBCUo7z+TL+8Nh 1vaFaazHFnUG9waVZw0T+26mAA3cCq/NAiyd/UZ/BCsyRPCKoRGo1571NmL7MCixkVhP zcV5d0ZLc+tzrx3YkstZEjtYFm9APc9NxE+t2XklcH2QGMvWPGiJkUuYc7fls/dj2MY+ jHQhuLpAp39TGPskhnMOeS2+53lo3fuhaNHwOFKYi01tvWaYRmjcNvaTr7LHxvUkv7OF Vc5w== X-Gm-Message-State: ANhLgQ1Tua6Yk74g/ifUJhC0pz+ZqeaPmJO1Ieldm+ndfdF1dsStvgCv 2IAO+AZhG2J+vCkzj+lskSs5jH+iEGwfxrvlFmg2j7FT/N0xeg== X-Google-Smtp-Source: ADFU+vvNZPT5mP5u3ejTzVkxHis6rfcBsJa+hQHBqsn7a0Yb/TT2DcUIcduMz9JRkHv5uFBpWQh0Xfp+sleN6Z3NxhU= X-Received: by 2002:aca:5444:: with SMTP id i65mr3466505oib.101.1585060934996; Tue, 24 Mar 2020 07:42:14 -0700 (PDT) MIME-Version: 1.0 References: <83024641-7bd3-b47f-cd2c-0d831279086d@ti.com> In-Reply-To: <83024641-7bd3-b47f-cd2c-0d831279086d@ti.com> From: "Lad, Prabhakar" Date: Tue, 24 Mar 2020 14:41:48 +0000 Message-ID: Subject: Re: PCIe EPF To: Kishon Vijay Abraham I Cc: Lorenzo Pieralisi , linux-pci Content-Type: text/plain; charset="UTF-8" Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Kishon, On Tue, Mar 24, 2020 at 1:58 AM Kishon Vijay Abraham I wrote: > > Hi Prabhakar, > > On 3/22/2020 4:19 AM, Lad, Prabhakar wrote: > > Hi Kishon, > > > > On Fri, Mar 20, 2020 at 5:28 AM Kishon Vijay Abraham I wrote: > >> > >> Hi Prabhakar, > >> > >> On 3/18/2020 5:07 PM, Lad, Prabhakar wrote: > >>> Hi Kishon, > >>> > >>> I rebased my rcar-endpoint patches on endpoint branch, which has > >>> support for streaming DMA API support, with this read/write/copy > >>> tests failed, to make sure nothing hasn't changed on my driver I > >>> reverted the streaming DMA API patch > >>> 74b9b4da84c71418ceeaaeb78dc790376df92fea "misc: pci_endpoint_test: Use > >>> streaming DMA APIs for buffer allocation" and tests began to pass > >>> again. > >>> > >>> If add a GFP_DMA flag for kzalloc (with streaming DMA), the test cases > >>> for read/write/copy pass as expected. > >>> > >>> Could you please through some light why this could be happening. > >> > >> Do you see any differences in the address returned by dma_map_single() like is > >> it 32-bit address or 64-bit address? > >> > > Both return 32 bit address, debugging further I see that with > > GFP_KERNEL flag for small buffer > > sizes the read/write/copy tests pass(upto 4k), so I am suspecting its > > related to caching probably. > > Also adding wmb()/rmb() just with GFP_KERNEL flag didn't help. Note I > > am using PIO transfers. > > Any thoughts on how we tackle it ? > > > > # With GFP_KERNEL flag > > root@hihope-rzg2m:~# pcitest -r > > [ 46.210649] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > > kzalloc:ffff0004b4ae0000 dma:7e99d000 align:ffff0004b4ae0000 > > READ ( 102400 bytes): NOT OKAY > > root@hihope-rzg2m:~# pcitest -r > > [ 51.880063] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > > kzalloc:ffff0004b4ae0000 dma:7e9c0000 align:ffff0004b4ae0000 > > READ ( 102400 bytes): OKAY > > Here one of the read test is passing and the other is failing. > For the 1st case dma:7e99d000, address is aligned to 4K > For the 2nd case dma:7e9c0000, address is aligned to 256K > > I'm suspecting this could be an alignment issue. Does the outbound ATU of your > EP has any restrictions? (like the address should be aligned to the size?). > There isn't any restriction for outbound ATU on ep, Although I tried alignment from SZ_1 - SZ_256K and each failed at several points. With GFP_KERNEL | GFP_DMA, as in my previous dump here the address too is not aligned to 256 but still read passes. root@hihope-rzg2m:~# pcitest -r -s 16384 [ 186.629347] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read kzalloc:ffff00003b848000 dma:7b848000 align:ffff00003b848000 READ ( 16384 bytes): OKAY And I have verified with GFP_KERNEL | GFP_DMA on my platform everything works as expected, So how about a patch for pci_endpoint_test.c, where flags are passed as part of driver_data and it defaults to just GFP_KERNEL ? Cheers, --Prabhakar > Thanks > Kishon > > > root@hihope-rzg2m:~# pcitest -r > > [ 53.354830] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > > kzalloc:ffff0004b4ae0000 dma:7e9e2000 align:ffff0004b4ae0000 > > READ ( 102400 bytes): NOT OKAY > > root@hihope-rzg2m:~# pcitest -r > > [ 55.307236] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > > kzalloc:ffff0004b4ae0000 dma:7ea04000 align:ffff0004b4ae0000 > > READ ( 102400 bytes): NOT OKAY > > root@hihope-rzg2m:~# pcitest -r > > [ 57.098626] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > > kzalloc:ffff0004b4ae0000 dma:7ea23000 align:ffff0004b4ae0000 > > READ ( 102400 bytes): NOT OKAY > > > > # GFP_KERNEL | GFP_DMA > > > > root@hihope-rzg2m:~# pcitest -r -s 1024001 > > [ 174.562071] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > > kzalloc:ffff00003b900000 dma:7b900000 align:ffff00003b900000 > > READ (1024001 bytes): OKAY > > root@hihope-rzg2m:~# pcitest -r -s 16384 > > [ 186.629347] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > > kzalloc:ffff00003b848000 dma:7b848000 align:ffff00003b848000 > > READ ( 16384 bytes): OKAY > > root@hihope-rzg2m:~# pcitest -r -s 8192 > > [ 190.578335] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > > kzalloc:ffff00003b840000 dma:7b840000 align:ffff00003b840000 > > READ ( 8192 bytes): OKAY > > root@hihope-rzg2m:~# pcitest -r -s 128 > > [ 199.428021] pci-endpoint-test 0000:01:00.0: pci_endpoint_test_read > > kzalloc:ffff00003b800000 dma:7b800000 align:ffff00003b800000 > > READ ( 128 bytes): OKAY > > root@hihope-rzg2m:~# > > > > Cheers, > > --Prabhakar > > > >> Thanks > >> Kishon