From patchwork Mon Jan 24 18:38:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 535504 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B9D3C4332F for ; Mon, 24 Jan 2022 21:34:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1453485AbiAXVaP (ORCPT ); Mon, 24 Jan 2022 16:30:15 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:41166 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1450097AbiAXVTp (ORCPT ); Mon, 24 Jan 2022 16:19:45 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1E9A160C60; Mon, 24 Jan 2022 21:19:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB62EC340E4; Mon, 24 Jan 2022 21:19:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643059184; bh=xjuXw+oaZke5wdTWzdveNvRQbUT4Qxd8QENQw3Rl7Co=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qUP/ftJS2ZNHPRRFXMo5KdErx7r1dgzrc813Sb0iKj8qvNEJCKrKmIVu4+bm2+PbW sh1qHMCw7N/wnaR+n9ZTqwGzde6oE6bHpV1lj1hB2twfM4BRgWCP/ke50SWeTj+iho wAtHM8r1t6HC46nKiIaRt8lB55+QSS6nVg+W1WK4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mike Rapoport , Douglas Anderson , Nicolas Boichat , Quentin Perret , Jan Kiszka , Stephen Boyd , Rob Herring , Sasha Levin Subject: [PATCH 5.16 0531/1039] of/fdt: Dont worry about non-memory region overlap for no-map Date: Mon, 24 Jan 2022 19:38:40 +0100 Message-Id: <20220124184143.137270584@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184125.121143506@linuxfoundation.org> References: <20220124184125.121143506@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Stephen Boyd [ Upstream commit da17d6905d29ddcdc04b2fdc37ed8cf1e8437cc8 ] In commit 8a5a75e5e9e5 ("of/fdt: Make sure no-map does not remove already reserved regions") we returned -EBUSY when trying to mark regions as no-map when they intersect with reserved memory. The goal was to find bad no-map reserved memory DT nodes that would unmap the kernel text/data sections. The problem is the reserved memory check will still trigger if the DT has a /memreserve/ that completely subsumes the no-map memory carveouts in the reserved memory node _and_ that region is also not part of the memory reg property. For example in sc7180.dtsi we have the following reserved-memory and memory node: memory@80000000 { /* We expect the bootloader to fill in the size */ reg = <0 0x80000000 0 0>; }; smem_mem: memory@80900000 { reg = <0x0 0x80900000 0x0 0x200000>; no-map; }; and the memreserve filled in by the bootloader is /memreserve/ 0x80800000 0x400000; while the /memory node is transformed into memory@80000000 { /* The bootloader fills in the size, and adds another region */ reg = <0 0x80000000 0 0x00800000>, <0 0x80c00000 0 0x7f200000>; }; The smem region is doubly reserved via /memreserve/ and by not being part of the /memory reg property. This leads to the following warning printed at boot. OF: fdt: Reserved memory: failed to reserve memory for node 'memory@80900000': base 0x0000000080900000, size 2 MiB Otherwise nothing really goes wrong because the smem region is not going to be mapped by the kernel's direct linear mapping given that it isn't part of the memory node. Therefore, let's only consider this to be a problem if we're trying to mark a region as no-map and it is actually memory that we're intending to keep out of the kernel's direct mapping but it's already been reserved. Acked-by: Mike Rapoport Cc: Douglas Anderson Cc: Nicolas Boichat Cc: Quentin Perret Cc: Jan Kiszka Fixes: 8a5a75e5e9e5 ("of/fdt: Make sure no-map does not remove already reserved regions") Signed-off-by: Stephen Boyd Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/20220107194233.2793146-1-swboyd@chromium.org Signed-off-by: Sasha Levin --- drivers/of/fdt.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 65af475dfa950..7e868e5995b7e 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -482,9 +482,11 @@ static int __init early_init_dt_reserve_memory_arch(phys_addr_t base, if (nomap) { /* * If the memory is already reserved (by another region), we - * should not allow it to be marked nomap. + * should not allow it to be marked nomap, but don't worry + * if the region isn't memory as it won't be mapped. */ - if (memblock_is_region_reserved(base, size)) + if (memblock_overlaps_region(&memblock.memory, base, size) && + memblock_is_region_reserved(base, size)) return -EBUSY; return memblock_mark_nomap(base, size);