From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f178.google.com (mail-pf1-f178.google.com [209.85.210.178]) (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 E96FD27732 for ; Sun, 10 May 2026 17:14:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778433262; cv=none; b=FpJBEXgXJzSZPLMtFn9nhlA7DTZgipUbuFBTh6qqff4Bt/4ImeDB36CMxf18NVGM0Rktu7y2aqfBzwvh7r4y79AD1kknnt2Dari/hUh17T8onWiqT1Q4v1BiT1poHdJvp282Guii7wS82DAD29ClA61SGeEC3LEmMBONtTN11Q4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778433262; c=relaxed/simple; bh=gxsMxa+7bOiJ/lDPJMvUarawGmDnhc42KlrWc5UapPw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u29mJ1EkMyMMMsF10/3vi3uWlbW9IEZpyeJEUqt9UCkbnFq5h0DOuGI4c57Hzp+2yuFeC2X4gq710l0eVplphy4chHXZoyy09Xj8qDUzqj7p3GGe3+RtoeOUfi/fHkgykBFq7reCAA9eAyDSDUUeIVIFGcBh3hvvseki66Qms+U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=QZafmxip; arc=none smtp.client-ip=209.85.210.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QZafmxip" Received: by mail-pf1-f178.google.com with SMTP id d2e1a72fcca58-83538fbd0b2so1411360b3a.0 for ; Sun, 10 May 2026 10:14:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1778433260; x=1779038060; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=AdiKoqOYaOQxpnoifZq+HXTmHH4BYLymY6DfpNxMI/U=; b=QZafmxipHfuRM4jhS/Y6CImomNKb9y2sQE4Mg0vLkQhjeuIUAUEpD9SJmmKpsRvTKs +h/IaUn18hZ0g0UkVmzWMbVZk/8AOPF5RwZbcF0kKbRYqhRC71rwUm4j6Iv0XDA+UPtY TQwqQvUppGL016lRsz9sRVJ6iTRjE3H02COziGiyYSGyiDKqpAgdKW7H25Dk094CvqhG aY7uUR2zQW85maStLAgqlVoc+XpX1zx1PPDVPWliln4BJ3U1cQFjeUeFSzm4IUCEvxWd q9vVce3E7snvpebVagt/h3yE0LbQJTb+XUUrsjXpz7YsunnK8YnWJwRs3bbRP1rmhVll Rsrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778433260; x=1779038060; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=AdiKoqOYaOQxpnoifZq+HXTmHH4BYLymY6DfpNxMI/U=; b=BxKHJtRjNP9qetD+RDLFdzGHqeST8Je2DyD5eATLAVQqas46otnknDSDvgLNxTQ2lM fcdmCv55ABTK5nROd756kaVA0t66z/7S1wqNjHsq1IpzV81qD9dMQCzk27dQi3Ygz/mo iiEQo1oLMsGyzyDU9ho9WKwgbYAzMj6wQcz3IF5433Ix0dWAjxKOoGA9WpxPN1BfZb5t 9es2lBOJWO+wem4vUWOxF9XWiG8saTiNhdtlQ5cdvuGirTnxfa9dKMdjneNnIWDd93Jg FmaZktIPQndri1SXy0ftswD3tKUbB1/7WENzLPuibRlTC+I0AxPJC+fWw/42BpyO7cUa k/9A== X-Forwarded-Encrypted: i=1; AFNElJ+MmWNgyB4ZIbqREZZe7GWPiFbukG9rXRW8sBG5umn/+2WU0mug3ETCjSQlowBhWjjV7rE7lDiFd1gy@vger.kernel.org X-Gm-Message-State: AOJu0YzkNovXwiq0N0pRmgtFFwbfWEdlvt53LFQz3SQfhsmSvGdbVD4J pii3X+v2mMV2EkPRg9MrEFgVV5JlB93nb670knBFjbzoofoCWASKxDm+ X-Gm-Gg: Acq92OHCCgIAhl5slrxtwaFMU0yBRec7NmSnK1ymKNg6V/lMWN6WwaNxm1eXVMd4zY9 vw/sQ6UETjjqy1nO5fjkTr4U0nZcSir153M8pjTYWBd3X+aZEC/eJ5kkvRYxf04BNDXQNKM9DMH 0CezHOTLgBJsFGofYodLM+uUV1y+NXAkopHpv7wQPFSIhvW20vVnJaiaGpmygbvFZoMdxW2fcIw WXTFjF8ic6CtdPj/JIDLRObeZ0RBvfAAILvVTsOZdrEvIeoxI0Em0a5Mcka+6n9q2/fbgLoLbud Fuk2D1iz+rkzjE708Z7IFVvkkc+rhanUiX1XUcq1WGDJqNnuh/T3ugVY3d7udyA7NLo2oTB3fwG kZnYR+CPr4GW8BE2HQrK+dqPqEAAQj+Y1VHimdmTDs2ElGB5Puq61Hd+4z/7ITfOMZ4TvWry6Bl kOTZNncUUleSWkleaMfw== X-Received: by 2002:a05:6a00:4389:b0:82f:9985:d4a1 with SMTP id d2e1a72fcca58-83e3b2da632mr6556120b3a.24.1778433260105; Sun, 10 May 2026 10:14:20 -0700 (PDT) Received: from ubuntu.. ([110.9.142.4]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-8396563f381sm21799778b3a.6.2026.05.10.10.14.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 10 May 2026 10:14:19 -0700 (PDT) From: Sang-Heon Jeon To: maddy@linux.ibm.com, mpe@ellerman.id.au, npiggin@gmail.com, chleroy@kernel.org, robh@kernel.org, saravanak@kernel.org Cc: linuxppc-dev@lists.ozlabs.org, devicetree@vger.kernel.org, Sang-Heon Jeon Subject: [PATCH 1/2] powerpc/prom: fix /chosen properties read from wrong node Date: Mon, 11 May 2026 02:13:52 +0900 Message-ID: <20260510171353.1406018-2-ekffu200098@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260510171353.1406018-1-ekffu200098@gmail.com> References: <20260510171353.1406018-1-ekffu200098@gmail.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Commit 60f20d84dc81 ("of/fdt: Rework early_init_dt_scan_chosen() to call directly") changed early_init_dt_scan_chosen() to be called directly instead of via of_scan_flat_dt(). After this change, early_init_dt_scan_chosen_ppc() does not behave as intended in either case below: - /chosen(or /chosen@0) exists: early_init_dt_scan_chosen() always succeeds, so early_init_dt_scan_chosen_ppc() then reads properties from the root node (first iteration) instead of chosen node. - /chosen does not exist: - Until commit 064e32dc5b03 ("of: fdt: Honor CONFIG_CMDLINE* even without /chosen node, take 2"), early_init_dt_scan_chosen() returns -ENOENT and early_init_dt_scan_chosen_ppc() returns 0. So of_scan_flat_dt() iterates over all remaining nodes. Not a bug but unnecessary. - After above commit, early_init_dt_scan_chosen() returns 0 and early_init_dt_scan_chosen_ppc() returns 1. So it reads properties from the root node (first iteration) instead of chosen node, same as the chosen node exist case above. Instead of using of_scan_flat_dt() for chosen node handling, first call early_init_dt_scan_chosen() directly to handle common chosen node properties. Then call early_init_dt_scan_chosen_ppc(), which is updated to handle powerpc-specific chosen node properties. Both now look up chosen node directly to avoid reading from the wrong node. Fixes: 60f20d84dc81 ("of/fdt: Rework early_init_dt_scan_chosen() to call directly") Signed-off-by: Sang-Heon Jeon --- QEMU-based test results $ fdtput -t bx chosen.dtb /chosen linux,crashkernel-base 00 00 00 10 00 00 00 00 $ fdtput -t bx chosen.dtb /chosen linux,crashkernel-size 00 00 00 02 00 00 00 00 $ qemu-system-ppc64 -M powernv9,dtb=chosen.dtb ... 1) AS-IS (before fix) # cat /sys/kernel/kexec_crash_size 0 2) TO-BE (after fix) # cat /sys/kernel/kexec_crash_size 33554432 --- arch/powerpc/kernel/prom.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index 9ed9dde7d231..34318ddb4a73 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -450,15 +450,17 @@ static int __init early_init_dt_scan_cpus(unsigned long node, return 0; } -static int __init early_init_dt_scan_chosen_ppc(unsigned long node, - const char *uname, - int depth, void *data) +static void __init early_init_dt_scan_chosen_ppc(void) { + const void *fdt = initial_boot_params; const unsigned long *lprop; /* All these set by kernel, so no need to convert endian */ + int node; - /* Use common scan routine to determine if this is the chosen node */ - if (early_init_dt_scan_chosen(data) < 0) - return 0; + node = fdt_path_offset(fdt, "/chosen"); + if (node < 0) + node = fdt_path_offset(fdt, "/chosen@0"); + if (node < 0) + return; #ifdef CONFIG_PPC64 /* check if iommu is forced on or off */ @@ -491,9 +493,6 @@ static int __init early_init_dt_scan_chosen_ppc(unsigned long node, if (lprop) crashk_res.end = crashk_res.start + *lprop - 1; #endif - - /* break now */ - return 1; } /* @@ -818,7 +817,8 @@ void __init early_init_devtree(void *params) * device-tree, including the platform type, initrd location and * size, TCE reserve, and more ... */ - of_scan_flat_dt(early_init_dt_scan_chosen_ppc, boot_command_line); + early_init_dt_scan_chosen(boot_command_line); + early_init_dt_scan_chosen_ppc(); /* Append additional parameters passed for fadump capture kernel */ fadump_append_bootargs(); -- 2.43.0