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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 2F8BCC8303D for ; Sat, 5 Jul 2025 11:44:09 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4bZ7vC4237z2y06; Sat, 5 Jul 2025 21:44:07 +1000 (AEST) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=63.228.1.57 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1751715847; cv=none; b=Uzi8BkJP5gsDLnlKpn3iZtBvZ/Hfi4KD9rY0i12dU7rEyDSPyJ1kxvxhX9cbofPxTJzN53vFf2lQpqKzWG6XV+q/g4mwB3BxXOYJK+WrC73dEAnKkVGOirhBxM0RI/cCzvW3XfPWxZlA6sf/9Jow3yl+3tDHX7pL2OnkjsIOjshG8xe4EEMEIbf+xkRcwksvxF5Ilk7fFzMqsmihJxiz9XSpbKJ2YpLNm9tPBrdqG8rrwr51jzTCd3o6NkAKk4c1Mk6b8LqSUnPvG+R1Pp023ngtpKhtAN4WAgqkrP407LQFiy4UamqyMPReJTCtDZIpVMVPesy2dX4F9TY4GvYLqA== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1751715847; c=relaxed/relaxed; bh=IvOQa11YbBFj7yBOidHoEYVqbRCUb5Oj+6ppKy7JZX8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OeTGeU5VRaBTQ2E0xFA9P2r5ffqkLMLVWEeztBeI5uRwj2kHoIur8CBcQcDT/VTWh0dfeU8AMjF295L+IdtobqbKcaJiuF8UIz5VtB0g5OKzn/vmfw3c3THFl2nXGLMIKCo1r1PfbyZYSTBPN2JhmzTkOAql1NEShs56MolsOOxoSlv/6yRMvuKjE2Ct++ZqGx7ZWQQvJCWC/kaSEWZyuDNnr5BSDSEsR51tcTLrWJLMku4wO3fuVkQ44xE0TeIQCL0Bs/raN0LAZIs5L0WOTgRCf+FZkz/kVPFLKXAsWiDH9rVkzG0z4sMNNl9yH+SuMEcfFt4u2l12YlMnfYqbfQ== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org; spf=pass (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.crashing.org Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=lists.ozlabs.org) Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by lists.ozlabs.org (Postfix) with ESMTP id 4bZ7vB0X13z2xlL for ; Sat, 5 Jul 2025 21:44:04 +1000 (AEST) Received: from gate.crashing.org (localhost [127.0.0.1]) by gate.crashing.org (8.18.1/8.18.1/Debian-2) with ESMTP id 565BgrOk149573; Sat, 5 Jul 2025 06:42:53 -0500 Received: (from segher@localhost) by gate.crashing.org (8.18.1/8.18.1/Submit) id 565BgnHF149569; Sat, 5 Jul 2025 06:42:49 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Sat, 5 Jul 2025 06:42:49 -0500 From: Segher Boessenkool To: Christophe Leroy Cc: David Laight , Michael Ellerman , Nicholas Piggin , Naveen N Rao , Madhavan Srinivasan , Alexander Viro , Christian Brauner , Jan Kara , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Darren Hart , Davidlohr Bueso , Andre Almeida , Andrew Morton , Dave Hansen , Linus Torvalds , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 0/5] powerpc: Implement masked user access Message-ID: References: <20250622172043.3fb0e54c@pumpkin> <20250624131714.GG17294@gate.crashing.org> <20250624175001.148a768f@pumpkin> <20250624182505.GH17294@gate.crashing.org> <20250624220816.078f960d@pumpkin> <83fb5685-a206-477c-bff3-03e0ebf4c40c@csgroup.eu> <20250626220148.GR17294@gate.crashing.org> <3e9bff9f-1aaf-4e91-a6c0-328a343d18f1@csgroup.eu> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3e9bff9f-1aaf-4e91-a6c0-328a343d18f1@csgroup.eu> Hi! On Sat, Jul 05, 2025 at 12:55:06PM +0200, Christophe Leroy wrote: > > > For book3s64, GCC only use isel with -mcpu=power9 or -mcpu=power10 > > > > I have no idea what "book3s64" means. > > Well that's the name given in Linux kernel to the 64 bits power CPU > processors. A fantasy name. Great. > > What is "powerpc/32"? It does not help if you use different names from > > what everyone else does. > > Again, that's the way it is called in Linux kernel, refer below commits > subjects: And another. > It means everything built with CONFIG_PPC32 Similar names for very dissimilar concepts, even! Woohoo! > > > For powerpc/64 we have less constraint than on powerpc32: > > > - Kernel memory starts at 0xc000000000000000 > > > - User memory stops at 0x0010000000000000 > > > > That isn't true, not even if you mean some existing name. Usually > > userspace code is mapped at 256MB (0x10000000). On powerpc64-linux > > anyway, different default on different ABIs of course :-) > > 0x10000000 is below 0x0010000000000000, isn't it ? So why isn't it true ? I understood "starts at". I read cross-eyed maybe, hehe. Segher