From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f172.google.com (mail-qk1-f172.google.com [209.85.222.172]) (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 90AA13AB466 for ; Mon, 13 Jul 2026 12:00:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783944058; cv=none; b=Rp3g/7ejSNC3FGGZ1bNXJldhhdAQ/3Zcs4Jdn+gxYD8DR7N7FQcUxvdDlsbMmmp3ntMvmOzlD2VT2cQZKv0B138Z3q3UUYbxd5KNxY69IcbYhwU0kBfK7cM14WxmSeHhsXvZfVX6vz6MbfAvWkfsS58xbyAHtLUc6SJ5Af8GA3c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783944058; c=relaxed/simple; bh=cw4aY6+xvzrYm0iCO2mGlo5F7FyS7T8m2XSxQSLnD5Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=R44eIi+qOfcXO0b1ZWJ7tHIZXAZU8jAU/veA18wh4JhdlRn44FO2qUZbpEMwFStdzUcqY1x7wgF5vJ6nvPKs0337N/bo2zsNvtK+1+D0k1FHBEkD3R1cgek8WnG3Onp9FukXNBMwDeby6KkHJBGdeLaJVOctGLf5kjGAtAviOmA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca; spf=pass smtp.mailfrom=ziepe.ca; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b=QnUNYp59; arc=none smtp.client-ip=209.85.222.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="QnUNYp59" Received: by mail-qk1-f172.google.com with SMTP id af79cd13be357-92e855da580so242450885a.1 for ; Mon, 13 Jul 2026 05:00:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1783944055; x=1784548855; darn=lists.linux.dev; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=5HCZAcclosWUynw+gIE6OLmOTVWR8tes+S5wt04CaM8=; b=QnUNYp59iEqsjLqp9g34zLI/dm2mokl92MXzQOudKq60YSqM/KifVJzsUk/OL/gTIS 8MA9f4YC5qHGuxL+XRtJ1qA8rsELZmSlsZ95bgrIJqybhHtGBAe87ktRgfu4aO9yAopt YSSozUi+mfoMeLnmiCJmrjH2cxMrKVC8FacHuamQlkE6Rb4txWJyVA8khDPGHm2xFmMO H0oPj3UazXfkcoNd3ZndkDM2Lw9cdjQAe8DtaVByf2JLqIh1WdgKEkzEz1/edw07hwjM TkqfDp6L4odq7a8B8oeAA0hVwuIqs6v0Pl3lbmRtElpdDgw8gvuMr93a/kTpHuTvtCjq NOsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783944055; x=1784548855; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=5HCZAcclosWUynw+gIE6OLmOTVWR8tes+S5wt04CaM8=; b=kPXLe8fBiae//iBLEu+WWkdVbRhHHx+/K5ceKK1E8PCa+UExShaV7P8fqE3TQos1o2 0wxJRrHzl/98lgqXTzm/j43sNfJ68l+VoSmyKVx4hdL5qX8WW3soeDjLsCfkzuOIjOYJ 8UbWGgCWG7Ha7XRFtGPcdGkiDAoCWoP+rdEUw3PBEutX1wIRt+9otBxP4xv07AIL0VgV E/vkGomDhxZcgnANnzCIRXRO2ZVpFVzdysT8eTSE904Q+11GN13BA3Yc0W1X2FU7Z1YS BfrIl5WCz9voIorqS6Jl63jL1Z1u2zjTmOH54fESzHAL3zOzLlM0RBTASsL2crJTwzlZ RuNw== X-Forwarded-Encrypted: i=1; AHgh+RpJpV8ELarGyjliIxb3VUzPGQEz2pp5BzwYIF57+TfELG6d3LJghVCDZzmTacYC8FOaYMyLug==@lists.linux.dev X-Gm-Message-State: AOJu0YzXsAKJ5oAFFb5GqsEvsZoMjlhz+m3T8pDGaiKM6iSgdY4MwXXp ktXU4EPMujDscpFKaIw9bnCfVeWzdtVWjnuCVogHEC2YR36chdD5pAls81Fih+Ga6E4= X-Gm-Gg: AfdE7ckgOVzVMvk2OLlbJdqIscsNvHUcr2rqC1O3wMAOgSvP5P0yE2uMLszmuNry36l wsAEViJNsuzRazowVWi7GhVOD8sR5GfhIYglNGSigd/sHi6s1wvhMaRbCPj8cPkpwh1fdUbmItd jn1Ahmhnl0/gDRECKdiYQ1i2mcTW9yX/9IXA0ItsaqQygBOgXhgSmN/2sw4I1ty+hMJStq+OXIn wLwWheGhd6JRo9hJfxwCos4dGyiFfdudoSBAkrpB0Lgzsf8i140iUBFJtrHlcjB9MB0zgSefxqC gI6YrG0ya2fKyczCUk8XCfmlY53sIWXquhW57hkYCXAduSps88Vzzy/Ue1xxs3eRLt2nwjzcTQq 1UeuU3m2TOe+vaCAV9ZOn13sX8HVzjrmvLBLuHXShUqZPaITbA2VIQRnsQdjXVseO01+iPGA= X-Received: by 2002:a05:620a:1712:b0:92e:5612:ba39 with SMTP id af79cd13be357-92ef2cb1651mr868484785a.44.1783944055161; Mon, 13 Jul 2026 05:00:55 -0700 (PDT) Received: from ziepe.ca ([159.2.72.92]) by smtp.gmail.com with ESMTPSA id af79cd13be357-92ee5cf9b7dsm1066306685a.23.2026.07.13.05.00.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jul 2026 05:00:54 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1wjFLB-0000000Cu4e-38Ps; Mon, 13 Jul 2026 09:00:53 -0300 Date: Mon, 13 Jul 2026 09:00:53 -0300 From: Jason Gunthorpe To: Nick Hollinghurst Cc: Daniel Drake , "Joerg Roedel (AMD)" , Will Deacon , Robin Murphy , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Florian Fainelli , Broadcom internal kernel review list , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 4/6] iommu/generic_pt: Add Broadcom BCM2712 page table format Message-ID: <20260713120053.GE1835788@ziepe.ca> References: <20260712-bcm2712-iommu-submit-v1-0-80e10cdde2ea@reactivated.net> <20260712-bcm2712-iommu-submit-v1-4-80e10cdde2ea@reactivated.net> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Jul 13, 2026 at 11:02:15AM +0100, Nick Hollinghurst wrote: > Hi Daniel, > > On Sun, 12 Jul 2026 at 22:19, Daniel Drake wrote: > > > > The BCM2712 IOMMU implements a 2-level page table format. It is relatively > > simple, with one unusual aspect: leaf entries can only be installed at > > Level 0. > > I should admit that a single-level huge page mapping is possible, but > I was too lazy to implement it (and haven't much tested it). > > It can be done by setting bits 31, 30 and 28 of the top-level entry > (all other combinations of bits 31, 30 will point to a next-level > table). The page number is in 4K units but must be 4MB aligned. Let's do that instead of the weird full level contiguation page thing please Jason