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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9092EC88E53 for ; Tue, 15 Sep 2026 04:43:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:Message-ID:Date:Subject:Cc:To:From:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=iDBR88Kq1bFU8YSncqnOxECCzfjGRrt18SSlVQzNBnc=; b=vl0kvCaEkmVC6PA6lD2EQiFm13 SXE9W1qvPlGN3dssxx3SQcuJzavyHtsW3iwtHSuPrsezyr9757HYWQK/xSwEq5wOFuOIE9QUtJYjq dI062IGwF6Q6zlhToa+SuQ/UQOSVRrDkgWn0BvbXwg9wjtv9CuXOaureoQVnLgx4zb0t2KMAFFx4a VCgJ4GGSqrQHqAyUruqDxuPGjcWHqU36bTksa2muVLyXy61tJc1vMRoTVyjUUvDsnQmquNf18AorP WGZuvcZdsOJCzHUbCUR+dxOvb2MdINV8pn+YAmo66xJQgzlBmQhaGEeGz1oz/BveUnp8qHllQ+KxN SIBsiGdw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6L0n-00000005CWv-3jYX; Tue, 15 Sep 2026 04:43:17 +0000 Received: from mail.mdapi.ch ([31.3.128.54]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6L0k-00000005CUO-3B8N; Tue, 15 Sep 2026 04:43:16 +0000 From: Martino Dell'Ambrogio DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tillo.ch; s=mail202603; t=1789447378; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=iDBR88Kq1bFU8YSncqnOxECCzfjGRrt18SSlVQzNBnc=; b=PPSoj7PgCTlMLla4350sZgDJzIx+8rTgGOjNPZe/8yjpHw/erLp7sBJIKRyL4Q0DGFFEES EOHypxEvIX9IQLMiyt4D1pNU4m5sUDJm9S4W/mviqw44fezn5wsj/atoTua336GyBgO+Sx 3Ke3NU5c08uPO9p0GmAXn1OCT9x+OEVGupg0kPo7RDXGEtsV26T65sB4R5u/n8sJoZM9Dq L4QTolYeMLexySoXGEkLqUzBoI6PZsVqhxG2u7Z3nSwnHU4AApJVk/72Jdj5KPvYm/M7wy Y58qs1XXSkMlQ3h1FetjarEwgC45NJLH870d8KGTSMJtgWLgYL+dWQ0Deh/Kmg== To: Matthias Brugger , AngeloGioacchino Del Regno Cc: linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kees@kernel.org, tony.luck@intel.com, gpiccoli@igalia.com Subject: [PATCH v3] arm64: dts: mediatek: mt7988a-bananapi-bpi-r4: add ramoops region Date: Tue, 15 Sep 2026 06:42:54 +0200 Message-ID: <20260915064254.1594808-1-tillo@tillo.ch> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260914_214315_063565_D7E8ACE3 X-CRM114-Status: GOOD ( 14.81 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org Reserve 1 MiB of RAM just below the ARM Trusted Firmware secmon region (0x42f00000-0x43000000) for persistent kernel log storage via pstore/ramoops, allowing post-panic console output and oops dumps to be recovered after a reboot. Without it, kernel crash logs on this board are lost when the SoC warm-resets and the on-chip console buffer is reinitialised. With record-size=128 KiB, console-size=256 KiB, ftrace-size=64 KiB and pmsg-size=64 KiB, ramoops_probe() carves the post-console remainder (640 KiB) into five 128 KiB kmsg records, with the requested ecc-size=16 reserving a small Reed-Solomon parity block from each zone's own allocation (per persistent_ram_new()). The ECC lets pstore recover dumps even when the panic path truncates writes mid-record. The no-map property is required so the reserved region is kept out of the kernel linear map. ramoops remaps the carve-out write-combine via ioremap_wc(); on arm64, leaving the same physical RAM mapped cacheable in the linear map at the same time is an attribute-mismatch and risks losing panic data to dirty cache evictions from the linear alias. The carve-out sits immediately below the ATF region already declared at 0x43000000 in mt7988a.dtsi, so no other reserved-memory child is moved or resized. BPI-R4 ships with at least 4 GiB of DRAM starting at 0x40000000, so the region is well within installed memory on every variant. For the carve-out to actually preserve content across a reset, the boot loader must also avoid touching this region on warm reset; on standard BPI-R4 boards with the stock OpenWrt U-Boot fork this already holds. Signed-off-by: Martino Dell'Ambrogio --- Changes in v3: - Resend; no functional change. Rebased on v7.3-rc3, where the v2 diff still applies unmodified. - v2 drew no review comments. It was also sent, in error, as a reply to the BPI-R3 patch's thread rather than its own, so it is likely to have been read as a duplicate of that board's patch. This version starts a fresh thread to avoid repeating that. The matching BPI-R3 (mt7986a) patch is being resent as v3 at the same time. v2: https://lore.kernel.org/all/20260528123645.2650085-1-tillo@tillo.ch/ v1: https://lore.kernel.org/all/20260528092807.1936177-1-tillo@tillo.ch/ .../boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dtsi | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dtsi b/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dtsi index 0ff69da..6a8dc89 100644 --- a/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dtsi +++ b/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dtsi @@ -80,6 +80,19 @@ }; }; +&{/reserved-memory} { + ramoops@42f00000 { + compatible = "ramoops"; + reg = <0 0x42f00000 0 0x100000>; + no-map; + record-size = <0x20000>; + console-size = <0x40000>; + ftrace-size = <0x10000>; + pmsg-size = <0x10000>; + ecc-size = <16>; + }; +}; + &cci { proc-supply = <&rt5190_buck3>; }; -- 2.47.3