From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rdsX62DD2zDqmL for ; Tue, 28 Jun 2016 14:00:06 +1000 (AEST) Message-ID: <1467086399.32607.5.camel@ellerman.id.au> Subject: Re: [PATCH v20 14/14] Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec From: Michael Ellerman To: Thiago Jung Bauermann , Geoff Levand , James Morse , kexec@lists.infradead.org, linuxppc-dev@lists.ozlabs.org Date: Tue, 28 Jun 2016 13:59:59 +1000 In-Reply-To: <9127562.8x2DzY0I6N@hactar> References: <9127562.8x2DzY0I6N@hactar> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2016-06-27 at 15:22 -0300, Thiago Jung Bauermann wrote: > Am Donnerstag, 23 Juni 2016, 17:54:49 schrieb Geoff Levand: > > +linux,usable-memory > > +------------------- > > + > > +This property is set on PowerPC and arm64 by kexec-tools during kdump > > +to tell the crash kernel the base address of its reserved area of memory, > > and +the size. e.g. > > + > > +/ { > > + chosen { > > + linux,usable-memory = <0x9 0xf0000000 0x0 0x10000000>; > > + }; > > +}; > > On powerpc, linux,usable-memory isn't in /chosen. It is put by kexec-tools > in each /memory node and has the same format as the reg property. During > early boot, the kernel goes through the /memory nodes to find usable memory > and for each node, if there's a linux,usable-memory property it will use it > instead of the reg property to find the ranges of memory it can use (see > early_init_dt_scan_memory in drivers/of/fdt.c). Yep that sounds right to me. Added in: ba7594852f4e ("[PATCH] powerpc: Add support for "linux,usable-memory" on memory nodes") cheers