From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 46B22606B5AC for ; Thu, 12 Nov 2026 11:26:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=rvez/PO1; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=h/r3xrdE 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: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=GZ4lZp1oW2s0U2uL8ErHvlu8up2Pjx215zhjtPcKJ2Q=; b=rvez/PO1gjF393 Lpru1tw7ZPbSCywgo4HHJYJIqRvzkaF9pZx/U4tQvWwpJGv3+soX/WTYfUHlCtoCoFEvdoAaDx6n6 nzhaR27RHdDpObmWzXveJQ3S1Gl+rXlQBHazZhw5f3g9xH+QO8pKJ0R/CNeRlaT0/Kpgb74AmF/7N YdRQ0Ef50GMNS+yBE92lxhgh1pRO78Xzz6jWZccsCguf9Qsf8eX+Poi9bu3z9N1x5B2rcAQHuFLtI LyaqE2Zz2NYDxOetR0MpRuhynhIwTkWGj5HySQWufEGpR1FWtb69+oVCmZdYZLGPsy+2tgtI1aQSW 3RGDD3SMAJ8ZeO3HrPTA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xRSwl-00000009gvt-0ffj; Thu, 12 Nov 2026 11:26:27 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xRSwX-00000009gnD-0DnQ for linux-arm-kernel@lists.infradead.org; Thu, 12 Nov 2026 11:26:13 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 39F5941325; Thu, 12 Nov 2026 11:26:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7EC0C1F00A05; Thu, 12 Nov 2026 11:26:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794482772; bh=GZ4lZp1oW2s0U2uL8ErHvlu8up2Pjx215zhjtPcKJ2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=h/r3xrdEhQleZV4yGgXPVqBfanfjsSKJ/g60PP/OJoc5XviAAJAUlX2KuMamvkihO 6S5H6k5b1RNd4xXJLVJ91kcuCCQCZTXO1k+1hQn6/O+7RvV8jNjkBRJXIlQ1V9idnR 9XiRe0gigvMNyWa7iIbigaFbf2JOHB8+iOYN0Ye9RreZ/JWwevZQj5VfLzPUXudYPN 9zN8Zh9SPvZmpMfi3VkkfJS4yMkZoVwR2dg8Pxff5QMrY76ACoV9Zd44FOHqSG8vPH /mQ1HwpQ/1l+8doGR2M/t4fFEC8tmhl4Zq43fF36z8VjNjv8+aaMf4c4pJisKk9Stz Dl7K858NfhsuA== From: Arnd Bergmann To: linux-mm@kvack.org Cc: Arnd Bergmann , Andrew Morton , Andreas Larsson , "Christophe Leroy (CS GROUP)" , Dave Hansen , "David Hildenbrand (Arm)" , Jason Gunthorpe , Linus Walleij , "Lorenzo Stoakes (ARM)" , Matthew Wilcox , Malin Jonsson , Richard Weinberger , Russell King , linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org Subject: [PATCH v2 6/6] ARM: add CONFIG_VMSPLIT_2G_OPT option Date: Thu, 12 Nov 2026 12:25:28 +0100 Message-ID: <20261112112528.1116405-7-arnd@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261112112528.1116405-1-arnd@kernel.org> References: <20261112112528.1116405-1-arnd@kernel.org> X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 From: Arnd Bergmann Unlike x86 and powerpc, there is currently no option to use exactly 2GiB of lowmem on Arm. Since 2GiB is still a relatively common configuration on embedded systems, it makes sense to allow this to be used in non-highmem builds. Add the Kconfig option and make this the default for non-LPAE builds with highmem enabled instead of CONFIG_VMSPLIT_2G. LPAE still requires the vmsplit to be on a gigabyte boundary, so this is only available for classic pagetables at the moment, same as CONFIG_VMSPLIT_3G_OPT. Tested in qemu -M virt, both with and without HIGHMEM enabled. Signed-off-by: Arnd Bergmann --- arch/arm/Kconfig | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 797705a94b28..8992fedfdf37 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1025,7 +1025,8 @@ config BL_SWITCHER_DUMMY_IF choice prompt "Memory split" depends on MMU - default VMSPLIT_2G if HIGHMEM || ARM_LPAE + default VMSPLIT_2G if ARM_LPAE + default VMSPLIT_2G_OPT if HIGHMEM default VMSPLIT_3G_OPT help Select the desired split between kernel and user memory. @@ -1042,6 +1043,9 @@ choice bool "3G/1G user/kernel split (for full 1G low memory)" config VMSPLIT_2G bool "2G/2G user/kernel split" + config VMSPLIT_2G_OPT + depends on !ARM_LPAE + bool "2G/2G user/kernel split (for full 2G low memory)" config VMSPLIT_1G bool "1G/3G user/kernel split" endchoice @@ -1050,6 +1054,7 @@ config PAGE_OFFSET hex default PHYS_OFFSET if !MMU default 0x40000000 if VMSPLIT_1G + default 0x70000000 if VMSPLIT_2G_OPT default 0x80000000 if VMSPLIT_2G default 0xB0000000 if VMSPLIT_3G_OPT default 0xC0000000 @@ -1058,6 +1063,7 @@ config KASAN_SHADOW_OFFSET hex depends on KASAN default 0x1f000000 if PAGE_OFFSET=0x40000000 + default 0x4f000000 if PAGE_OFFSET=0x70000000 default 0x5f000000 if PAGE_OFFSET=0x80000000 default 0x9f000000 if PAGE_OFFSET=0xC0000000 default 0x8f000000 if PAGE_OFFSET=0xB0000000 -- 2.53.0