From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f47.google.com (mail-pj1-f47.google.com [209.85.216.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 44D9F7F for ; Fri, 21 Jul 2023 03:49:58 +0000 (UTC) Received: by mail-pj1-f47.google.com with SMTP id 98e67ed59e1d1-262e839647eso843604a91.2 for ; Thu, 20 Jul 2023 20:49:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1689911398; x=1690516198; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=PP+KsyysvUIQdJ6ewTv+F8ZGuWEA39fo13NEoHyitfw=; b=lfA3gYcio7s8oXJqeQSsLROwIgTtmn9LOUax/z/TlERlxHvwKQzbg+zITQWLHrNzOZ i/L6H22njmRWQXVDw7Grf+rfqBo7TsV6x+t0+NtQcXl8lGzjuWq5y+xOk2twOEkV2kSg hTb7rlHlVuJtZn1KBuI2WrO3+czJl4IKL+LK/AAfWFFdoSSL20ZV9I39ZDaQw6nHI+Z/ mcAfy7Q80bUPPoC2zVQNGaWWGFgC7LqKvVArO4LG/X1zh5wn0c3GypldFJz9qgxQ9Ckw 75pDvcoKVJJv+feLng3AmMxnYUsAVhWv8QuErq/4LdyOVLkF9rrGKdE3sLuRKXnHJiib 50sg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689911398; x=1690516198; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=PP+KsyysvUIQdJ6ewTv+F8ZGuWEA39fo13NEoHyitfw=; b=hE5D9Wz+bClsRBGTxlbUj4okEgbgxwsU+fOIxPZLqs51j3tT8c8q2i5HUXX8gQiWeY c5tEUpgvn1zbmSI1ArINyQpJMToRl1ZlyThqkSpJJGDivLHzFUyAQM7ZY6swnhFdyWgW jKyA6QZhqONh1fj8tdn21swPsiO94oz9L6zbYtNnckRm5ZPNDAcTGsU6njNxJkqXLcVD xtNPOeQSyvSORWuioUjvBwAeSX7MjkEsO+dnWKPc16msmF9PpdKKqvVU9qUmchTc/mQi cXV34JLjJ3eohEKKc/j0fNPVhdMkOcZcSqzH827SR1agL2f/eVjRlNBmYu5RtEf2rO12 sFyQ== X-Gm-Message-State: ABy/qLbDi/fzlKI4XpKnwY0hVbUPYAlGLBpc8g1JDS4J5JYnYkuQ/H9t Lqex9TARmeYB9nTycRZt+6x+HGA1bg+lI6r5PFGd/A== X-Google-Smtp-Source: APBJJlEr/VjirMVZtMc4cX0uJPsKqRsU32tlCDQs3tsf6K7eUQ4sFLhW24crr5+dorszKseHB0iIVKQGE8YGQVOmfI8= X-Received: by 2002:a17:90a:5a4c:b0:263:514:5ee3 with SMTP id m12-20020a17090a5a4c00b0026305145ee3mr605988pji.32.1689911398194; Thu, 20 Jul 2023 20:49:58 -0700 (PDT) Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <610abe685f90870be52bc7c2ca45ab5235bd8eb4.1689792825.git.tjeznach@rivosinc.com> <69800c58-2df8-25e5-09e0-c9929bae2193@kernel.org> <20230720-bully-famine-dfc9a5e688ef@spud> In-Reply-To: <20230720-bully-famine-dfc9a5e688ef@spud> From: Tomasz Jeznach Date: Thu, 20 Jul 2023 20:49:47 -0700 Message-ID: Subject: Re: [PATCH 05/11] RISC-V: drivers/iommu/riscv: Add sysfs interface To: Conor Dooley Cc: Krzysztof Kozlowski , Joerg Roedel , Will Deacon , Robin Murphy , Paul Walmsley , Palmer Dabbelt , Albert Ou , Anup Patel , Sunil V L , Nick Kossifidis , Sebastien Boeuf , iommu@lists.linux.dev, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux@rivosinc.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, Jul 20, 2023 at 3:08=E2=80=AFPM Conor Dooley wro= te: > > On Thu, Jul 20, 2023 at 11:37:50PM +0200, Krzysztof Kozlowski wrote: > > On 20/07/2023 20:30, Tomasz Jeznach wrote: > > > >>> +#define sysfs_dev_to_iommu(dev) \ > > >>> + container_of(dev_get_drvdata(dev), struct riscv_iommu_device,= iommu) > > >>> + > > >>> +static ssize_t address_show(struct device *dev, > > >>> + struct device_attribute *attr, char *buf) > > >> > > >> > > >> Where is the sysfs ABI documented? > > >> > > > > > > Sysfs for now is used only to expose selected IOMMU memory mapped > > > registers, with complete documentation in the RISC-V IOMMU Arch Spec > > > [1], and some comments in iommu-bits.h file. > > > LMK If it would be better to put a dedicated file documenting those > > > with the patch itself. > > > > I meant, you created new sysfs interface. Maybe I missed something in > > the patchset, but each new sysfs interface required documenting in > > Documentation/ABI/. > > | expose selected IOMMU memory mapped registers > > | Enable sysfs debug / visibility interface providing restricted > | access to hardware registers. > > Documentation requirements of sysfs stuff aside, I'm not sure that we > even want a sysfs interface for this in the first place? Seems like, if > at all, this should be debugfs instead? Seems like the only use case for > it is debugging/development... Thanks Conor, will switch to debugfs. This will be a more suitable interfac= e. regards, - Tomasz