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 93A49CCD1BF for ; Tue, 28 Oct 2025 06:24:16 +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-Type:In-Reply-To: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=zuGj1hW8mWz3shIq2GZWCMOifU7nzT6tSAo/1NZESWI=; b=OTjTMKj19l2LXo+C54nwvhM8jK Cny8gIb6EA6SM3XNh/fCFtez6oE/8k+R86wSfSTIeBMM1q0LtsezZZsAaBfCkfbXo1hX/++ojMhbu P/h0Z93yfEM1Ip79y2fRhbsQApt0Ty7RtD78VTMpAQdhgofMBQEQPDroD96eqvdO2JQsf7YBwj291 G4z2SVLIzmEy8MB7vRxLTaUnLpqjGmGW/K+MqH5Ma+ISCp2oySu0jfChWENlv51o6hr+1gJuRzpdB s9d2E+6AepeIA5qiRztsTozk8iG15+3yQ1lZf8DDihwWik+EBGv0CGZddigrKfbyIxzoz1/M1FXXt iCYqQACA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vDd7t-0000000FKU7-19oI; Tue, 28 Oct 2025 06:24:13 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vDd7q-0000000FKTH-0Yeu for kexec@lists.infradead.org; Tue, 28 Oct 2025 06:24:12 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1761632647; 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: in-reply-to:in-reply-to:references:references; bh=zuGj1hW8mWz3shIq2GZWCMOifU7nzT6tSAo/1NZESWI=; b=OEkby+cC18FNzCPYjanW751CFC2bNEujudiWZRHA0pKGQP43LiEUXsRoSEzjy36u0l/pSw YbQNVKj2mR70SKtbUKeYDPlJ7CRtsJudKPsD/BQXZHylViRDu+P0V7Y2a8ca6D3SB+b83o hXoVXb7B1VVPKToyzK0OWnnNqnZEF+8= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-265-92njuEYVOgKUgJEjxNPoCA-1; Tue, 28 Oct 2025 02:24:03 -0400 X-MC-Unique: 92njuEYVOgKUgJEjxNPoCA-1 X-Mimecast-MFC-AGG-ID: 92njuEYVOgKUgJEjxNPoCA_1761632641 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9EEE81956080; Tue, 28 Oct 2025 06:24:00 +0000 (UTC) Received: from localhost (unknown [10.72.112.212]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6C6FA1800353; Tue, 28 Oct 2025 06:23:58 +0000 (UTC) Date: Tue, 28 Oct 2025 14:23:53 +0800 From: Baoquan he To: Sourabh Jain , kexec@lists.infradead.org Cc: linuxppc-dev@lists.ozlabs.org, Hari Bathini , Madhavan Srinivasan , Mahesh Salgaonkar , Michael Ellerman , "Ritesh Harjani (IBM)" , Shivang Upadhyay Subject: Re: [PATCH 0/4] powerpc/kdump: Support high crashkernel reservation Message-ID: References: <20251027151338.819957-1-sourabhjain@linux.ibm.com> MIME-Version: 1.0 In-Reply-To: <20251027151338.819957-1-sourabhjain@linux.ibm.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: tVIDdPR_BpRQ4zPZuo_dBJjRS7TSB0ryXFIUEWZskrI_1761632641 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251027_232410_253589_B24FFF0B X-CRM114-Status: GOOD ( 17.85 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org Cc kexec mailing list. On 10/27/25 at 08:43pm, Sourabh Jain wrote: > Add support for reserving crashkernel memory in higher address ranges > using the crashkernel=xxM,high command-line option. > > With this feature, most of the crashkernel memory for kdump will be > reserved in high memory regions, while only a small portion (64 MB) will > be reserved in low memory for the kdump kernel. This helps free up low > memory for other components that require allocations in that region. > > For example, if crashkernel=2G,high is specified, the kernel will reserve > 2 GB of crashkernel memory near the end of system RAM and an additional > 64 MB of low memory (below 1 GB) for RTAS to function properly. > > Currently, this feature is supported only on PPC64 systems with 64-bit > RTAS instantiation and Radix MMU enabled. > > Two critical changes were made to support this feature: > > - CPU feature discovery is now performed before crashkernel > reservation. This ensures the MMU type is determined before reserving > crashkernel memory. (Patch 01/04) > > - RTAS instantiation has been moved to 64-bit mode. (Patch 02/04) > > Apply the following patch first, and then apply this patch series: > https://lore.kernel.org/all/20251024170118.297472-1-sourabhjain@linux.ibm.com/ > > Cc: Baoquan he > Cc: Hari Bathini > Cc: Madhavan Srinivasan > Cc: Mahesh Salgaonkar > Cc: Michael Ellerman > Cc: Ritesh Harjani (IBM) > Cc: Shivang Upadhyay > > Sourabh Jain (4): > powerpc/mmu: do MMU type discovery before crashkernel reservation > powerpc: move to 64-bit RTAS > powerpc/kdump: consider high crashkernel memory if enabled > powerpc/kdump: add support for high crashkernel reservation > > arch/powerpc/include/asm/book3s/64/mmu.h | 1 + > arch/powerpc/include/asm/crash_reserve.h | 8 +++++ > arch/powerpc/include/asm/kexec.h | 1 + > arch/powerpc/include/asm/mmu.h | 1 + > arch/powerpc/include/asm/rtas.h | 11 ++++++ > arch/powerpc/kernel/prom.c | 28 ++++++++------- > arch/powerpc/kernel/prom_init.c | 26 +++++++++++--- > arch/powerpc/kernel/rtas.c | 5 +++ > arch/powerpc/kernel/rtas_entry.S | 17 ++++++++- > arch/powerpc/kexec/core.c | 45 +++++++++++++++++------- > arch/powerpc/kexec/elf_64.c | 10 ++++-- > arch/powerpc/kexec/file_load_64.c | 5 +-- > arch/powerpc/kexec/ranges.c | 24 +++++++++++-- > arch/powerpc/mm/init_64.c | 27 ++++++++------ > 14 files changed, 161 insertions(+), 48 deletions(-) > > -- > 2.51.0 >