From owner-soc-status@freebsd.org Mon Jun 11 11:48:49 2018 Return-Path: Delivered-To: soc-status@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7538C1018260 for ; Mon, 11 Jun 2018 11:48:49 +0000 (UTC) (envelope-from pratiy0100@gmail.com) Received: from mail-wm0-f65.google.com (mail-wm0-f65.google.com [74.125.82.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id F0FD480090; Mon, 11 Jun 2018 11:48:48 +0000 (UTC) (envelope-from pratiy0100@gmail.com) Received: by mail-wm0-f65.google.com with SMTP id r125-v6so15882519wmg.2; Mon, 11 Jun 2018 04:48:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=ARtUE1vTgJ4O8VlrYcdIWdXHhLUI+oU/LnT0bp5k8+4=; b=Q8KTsp6Za0wGzABR89MCUeZUkNrDnK8lD3UfKEi+8lcX6xG1xlmf4E/PLUWc70QVVV m1aPUJDog/w/rC54XbTcuQDMyvdaWsGNvNyvhZcJphZ8Rus5RMotPQglHPKMcf7A8GwN G/sLZzYTi+k4emaHIumjHNmfs41wrW4TA52sAEjmz/obKHiVlRWfiqyBgREkmKxQiVBp Ah2DWUjqjbnUBXCDEVAUhccbw/0PacgwrOC07rhWfzDpWG0kKYxRKUHUUMYhKcv1jc4j TH8k+7T1y8nVAWQuweCIJdZLoip/linf5LNXW2GCDpaLN7azZk9y7RRZdLufEKGGOGbm +CVg== X-Gm-Message-State: APt69E3H+QHEtd8AlGE7HDRkFz6oWPHcVI+BMi8efnFT4fl7PGUtQjXV YIGQ6AtjG6tlb4iauWeZgeKgUXay X-Google-Smtp-Source: ADUXVKIhNUYxj2z+E9F/+O4YP7Qj7+t/grCkgYX8g8jiGkfCDtx1Im74sXq6GDfRDFOPNqxoJcfCuQ== X-Received: by 2002:a50:b376:: with SMTP id r51-v6mr18199222edd.145.1528717722490; Mon, 11 Jun 2018 04:48:42 -0700 (PDT) Received: from mail-wm0-f45.google.com (mail-wm0-f45.google.com. [74.125.82.45]) by smtp.gmail.com with ESMTPSA id x11-v6sm10571528edb.39.2018.06.11.04.48.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Jun 2018 04:48:42 -0700 (PDT) Received: by mail-wm0-f45.google.com with SMTP id j15-v6so15966031wme.0; Mon, 11 Jun 2018 04:48:42 -0700 (PDT) X-Received: by 2002:a50:b122:: with SMTP id k31-v6mr18508184edd.217.1528717722159; Mon, 11 Jun 2018 04:48:42 -0700 (PDT) MIME-Version: 1.0 From: Pratyush Yadav Date: Mon, 11 Jun 2018 17:18:05 +0530 X-Gmail-Original-Message-ID: Message-ID: Subject: [Week 4] Import the Xen grant-table bus_dma(9) handlers from OpenBSD To: soc-status@freebsd.org Cc: Edward Napierala , Akshay Jaggi Content-Type: text/plain; charset="UTF-8" X-BeenThere: soc-status@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: Summer of Code Status Reports and Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 11 Jun 2018 11:48:49 -0000 Hi, This week I finished up my implementation of the xen-specific bus_dma(9) handlers. I asked Roger Pau Monne for review. After his review, I realized I had been doing things a little wrong. I was building the Xen-specific handlers on top of the bus_dma(9) interface. Instead, I should have created an alternate busdma implementation, kind of like sys/x86/iommu/busdma_dmar.c So I had to study the inner details of the bus_dma(9) interface to learn how an alternate implementation can be written. This was a little confusing at the beginning.because there is no clear guide on the subsystem for beginners like me. But eventually, I got the hang of it, mostly by reading code already written. After that came the task of rewriting my implementation. I wrote it, and then spent a couple of days refining it. Today, I submitted it to Roger again for review. We are discussing it as of now. No major concerns have been raised so I should be done with the xen-specific busdma hooks in a few days. You can check out the code at [0]. I maintain a blog on Blogger where I publish my progress every few days. Check it out if you want more details on what I'm doing [1]. [0] https://github.com/prati0100/freebsd [1] http://pratyushgsoc.blogspot.in/2018/05/import-xen-grant-table-busdma9-handlers.html -- Regards, Pratyush Yadav