From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id D372AB7088 for ; Mon, 20 Jul 2009 22:46:12 +1000 (EST) Received: from mx2.redhat.com (mx2.redhat.com [66.187.237.31]) by ozlabs.org (Postfix) with ESMTP id 58EF0DDD01 for ; Mon, 20 Jul 2009 22:46:11 +1000 (EST) From: David Howells In-Reply-To: <20090715074952.A36C7DDDB2@ozlabs.org> References: <20090715074952.A36C7DDDB2@ozlabs.org> To: Benjamin Herrenschmidt Subject: Re: [RFC/PATCH] mm: Pass virtual address to [__]p{te, ud, md}_free_tlb() Date: Mon, 20 Jul 2009 13:46:03 +0100 Message-ID: <13548.1248093963@redhat.com> Sender: dhowells@redhat.com Cc: Linux-Arch , Nick Piggin , linuxppc-dev@ozlabs.org, Hugh Dickins , linux-kernel@vger.kernel.org, Linux Memory Management List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Benjamin Herrenschmidt wrote: > Upcoming paches to support the new 64-bit "BookE" powerpc architecture > will need to have the virtual address corresponding to PTE page when > freeing it, due to the way the HW table walker works. > > Basically, the TLB can be loaded with "large" pages that cover the whole > virtual space (well, sort-of, half of it actually) represented by a PTE > page, and which contain an "indirect" bit indicating that this TLB entry > RPN points to an array of PTEs from which the TLB can then create direct > entries. Thus, in order to invalidate those when PTE pages are deleted, > we need the virtual address to pass to tlbilx or tlbivax instructions. > > The old trick of sticking it somewhere in the PTE page struct page sucks > too much, the address is almost readily available in all call sites and > almost everybody implemets these as macros, so we may as well add the > argument everywhere. I added it to the pmd and pud variants for consistency. > > Signed-off-by: Benjamin Herrenschmidt Acked-by: David Howells [MN10300 & FRV]