From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3B5D914A62B; Sat, 5 Jul 2025 11:44:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=63.228.1.57 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751715861; cv=none; b=BtbrJrgvG6jznbcvypNGGBRmdXRJZUxkH2HHhWGI/4Hjbb5WdDvE3ITQ7EkhzNYChMIMUd723aCH1YQgKospBBaAP/vlKVZ52iKOHYEzuKFU5yGt9FnkI0aPOSJZNTxy5FUKr/gOl79gXnZMi2PiRztrW8feAxpWYah5ZSvWKL8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751715861; c=relaxed/simple; bh=t0dBI9KZ0iDXjtqjyaZZJtNRaNtXo7Pxi19Gsk1Xxuk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=o6KLC8XTYjb4sgcI+8E2KD9xKN2FtR0B0oNCXB4FhnlBrLP4ErB6QPdN2hFDSTpivauANoLB0G3fjlQb02dila2isqF7Bo4A1xSuyICD6wMe/O6BVuJJULasTqaW8hOXbHw3kUvB3Ka44gYzq66ZdcwUIy3fX6uzQ+wBUTRjiqQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org; spf=pass smtp.mailfrom=kernel.crashing.org; arc=none smtp.client-ip=63.228.1.57 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.crashing.org 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> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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