Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934485Ab1ETAjP (ORCPT ); Thu, 19 May 2011 20:39:15 -0400 Received: from gate.crashing.org ([63.228.1.57]:60783 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933220Ab1ETAjO (ORCPT ); Thu, 19 May 2011 20:39:14 -0400 Subject: Re: [PATCH 6/7] [RFC] enable early TLBs for BG/P From: Benjamin Herrenschmidt To: Eric Van Hensbergen Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, bg-linux@lists.anl-external.org In-Reply-To: <1305753895-24845-6-git-send-email-ericvh@gmail.com> References: <1305753895-24845-1-git-send-email-ericvh@gmail.com> <1305753895-24845-6-git-send-email-ericvh@gmail.com> Content-Type: text/plain; charset="UTF-8" Date: Fri, 20 May 2011 10:39:01 +1000 Message-ID: <1305851941.7481.92.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1443 Lines: 41 On Wed, 2011-05-18 at 16:24 -0500, Eric Van Hensbergen wrote: > BG/P maps firmware with an early TLB That's a bit gross. How often do you call that firmware in practice ? Aren't you better off instead inserting a TLB entry for it when you call it instead ? A simple tlbsx. + tlbwe sequence would do. That would free up a TLB entry for normal use. Cheers, Ben. > Signed-off-by: Eric Van Hensbergen > --- > arch/powerpc/include/asm/mmu-44x.h | 6 +++++- > 1 files changed, 5 insertions(+), 1 deletions(-) > > diff --git a/arch/powerpc/include/asm/mmu-44x.h b/arch/powerpc/include/asm/mmu-44x.h > index ca1b90c..2807d6e 100644 > --- a/arch/powerpc/include/asm/mmu-44x.h > +++ b/arch/powerpc/include/asm/mmu-44x.h > @@ -115,8 +115,12 @@ typedef struct { > #endif /* !__ASSEMBLY__ */ > > #ifndef CONFIG_PPC_EARLY_DEBUG_44x > +#ifndef CONFIG_BGP > #define PPC44x_EARLY_TLBS 1 > -#else > +#else /* CONFIG_BGP */ > +#define PPC44x_EARLY_TLBS 2 > +#endif /* CONFIG_BGP */ > +#else /* CONFIG_PPC_EARLY_DEBUG_44x */ > #define PPC44x_EARLY_TLBS 2 > #define PPC44x_EARLY_DEBUG_VIRTADDR (ASM_CONST(0xf0000000) \ > | (ASM_CONST(CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW) & 0xffff)) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/