From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from tx2outboundpool.messaging.microsoft.com (tx2ehsobe003.messaging.microsoft.com [65.55.88.13]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client CN "mail.global.frontbridge.com", Issuer "MSIT Machine Auth CA 2" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 303BE2C00A6 for ; Sat, 7 Dec 2013 06:10:12 +1100 (EST) Message-ID: <1386356996.7375.120.camel@snotra.buserror.net> Subject: Re: [PATCH] powerpc 8xx: Loading kernels over 8Mbytes without CONFIG_PIN_TLB From: Scott Wood To: Christophe Leroy Date: Fri, 6 Dec 2013 13:09:56 -0600 In-Reply-To: <20131127110406.6DC8E1A504F@localhost.localdomain> References: <20131127110406.6DC8E1A504F@localhost.localdomain> Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Cc: linuxppc-dev@lists.ozlabs.org, Paul Mackerras , linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2013-11-27 at 12:04 +0100, Christophe Leroy wrote: > Today, the only way to load kernels whose size is greater than 8Mbytes is to > activate CONFIG_PIN_TLB. Otherwise, the physical memory initially mapped is > limited to 8Mbytes. This patch sets up 24 Mbytes of initial memory regardless > of whether CONFIG_PIN_TLB is active or not. It allows to load "big" kernels > (for instance when activating CONFIG_LOCKDEP_SUPPORT) without having > to activate CONFIG_PIN_TLB. So, what happens on boards with less than 24M memory present? Even if you avoid explicitly referencing those addresses, what if there is a speculative access -- or does 8xx not do that? -Scott