From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A95A1267B04 for ; Thu, 13 Mar 2025 14:12:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741875134; cv=none; b=qMpog+JtX3nsM7nkTalET23Yx9gL8EnzhGYOzN1xUJY3ohA+EkXrfleFHYfWx3y0ZKQb9k9tqWiz0Osx/E/YFnDelymELEA1Q6rwGs3k3FanqvVB9SMEXSYudAV07CcMDx2EkizJ5PkplKXgWN7gYxZ7ZYtUXFoC/pdPV3KVWzQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741875134; c=relaxed/simple; bh=5xjCj3Uau/X756VnrbDbtV6ePBK/IMHky7tHSrV01Rc=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=cMMoL+MQ4lnElpSWTEYbaE9KosexpVtncyeDXeMjhupVKBh03nxlcqvnE/SREEPJECslWG/dj+A0+FZjKuw5nMYuySnJUvenQBa5YgoOuBVzLhNJRRHHhwZWJrNGUX6PEWmTbIlOnhD9cSyXDqgx+eNKh17cjQf3iJCMGVbJN3c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 745B3150C; Thu, 13 Mar 2025 07:12:22 -0700 (PDT) Received: from [10.57.40.246] (unknown [10.57.40.246]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0A7F23F694; Thu, 13 Mar 2025 07:12:07 -0700 (PDT) Message-ID: Date: Thu, 13 Mar 2025 14:12:06 +0000 Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 4/4] iommu: Get DT/ACPI parsing into the proper probe path From: Robin Murphy To: Marek Szyprowski , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , "Rafael J. Wysocki" , Len Brown , Russell King , Greg Kroah-Hartman , Danilo Krummrich , Stuart Yoder , Laurentiu Tudor , Nipun Gupta , Nikhil Agarwal , Joerg Roedel , Will Deacon , Rob Herring , Saravana Kannan , Bjorn Helgaas Cc: linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, linux-pci@vger.kernel.org, Charan Teja Kalla References: <9b358d68-332e-404e-9a75-740297f7b28d@samsung.com> <417d6f59-0d78-4e81-ad0b-e06846f786b0@arm.com> <016bb7ca-f0d3-464e-ac74-46e6f78e90d7@arm.com> Content-Language: en-GB In-Reply-To: <016bb7ca-f0d3-464e-ac74-46e6f78e90d7@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2025-03-13 1:06 pm, Robin Murphy wrote: > On 2025-03-13 12:23 pm, Marek Szyprowski wrote: >> On 13.03.2025 12:01, Robin Murphy wrote: >>> On 2025-03-13 9:56 am, Marek Szyprowski wrote: >>> [...] >>>> This patch landed in yesterday's linux-next as commit bcb81ac6ae3c >>>> ("iommu: Get DT/ACPI parsing into the proper probe path"). In my >>>> tests I >>>> found it breaks booting of ARM64 RK3568-based Odroid-M1 board >>>> (arch/arm64/boot/dts/rockchip/rk3568-odroid-m1.dts). Here is the >>>> relevant kernel log: >>> >>> ...and the bug-flushing-out begins! >>> >>>> Unable to handle kernel NULL pointer dereference at virtual address >>>> 00000000000003e8 >>>> Mem abort info: >>>>      ESR = 0x0000000096000004 >>>>      EC = 0x25: DABT (current EL), IL = 32 bits >>>>      SET = 0, FnV = 0 >>>>      EA = 0, S1PTW = 0 >>>>      FSC = 0x04: level 0 translation fault >>>> Data abort info: >>>>      ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 >>>>      CM = 0, WnR = 0, TnD = 0, TagAccess = 0 >>>>      GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 >>>> [00000000000003e8] user address but active_mm is swapper >>>> Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP >>>> Modules linked in: >>>> CPU: 3 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.14.0-rc3+ #15533 >>>> Hardware name: Hardkernel ODROID-M1 (DT) >>>> pstate: 00400009 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) >>>> pc : devm_kmalloc+0x2c/0x114 >>>> lr : rk_iommu_of_xlate+0x30/0x90 >>>> ... >>>> Call trace: >>>>     devm_kmalloc+0x2c/0x114 (P) >>>>     rk_iommu_of_xlate+0x30/0x90 >>> >>> Yeah, looks like this is doing something a bit questionable which can't >>> work properly. TBH the whole dma_dev thing could probably be cleaned up >>> now that we have proper instances, but for now does this work? >> >> Yes, this patch fixes the problem I've observed. >> >> Reported-by: Marek Szyprowski >> Tested-by: Marek Szyprowski >> >> BTW, this dma_dev idea has been borrowed from my exynos_iommu driver and >> I doubt it can be cleaned up. > > On the contrary I suspect they both can - it all dates back to when we > had the single global platform bus iommu_ops and the SoC drivers were > forced to bodge their own notion of multiple instances, but with the > modern core code, ops are always called via a valid IOMMU instance or > domain, so in principle it should always be possible to get at an > appropriate IOMMU device now. IIRC it was mostly about allocating and > DMA-mapping the pagetables in domain_alloc, where the private notion of > instances didn't have enough information, but domain_alloc_paging solves > that. Bah, in fact I think I am going to have to do that now, since although it doesn't crash, rk_domain_alloc_paging() will also be failing for the same reason. Time to find a PSU for the RK3399 board, I guess... (Or maybe just move the dma_dev assignment earlier to match Exynos?) Thanks, Robin.