From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 0B157DE1B4 for ; Wed, 30 Apr 2008 18:01:02 +1000 (EST) Message-Id: From: Kumar Gala To: Paul Mackerras In-Reply-To: <18455.59014.305281.949578@cargo.ozlabs.ibm.com> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Mime-Version: 1.0 (Apple Message framework v919.2) Subject: Re: [PATCH] [POWERPC] convert transfer_to_handler into a macro Date: Wed, 30 Apr 2008 03:00:56 -0500 References: <18455.37613.709102.30668@cargo.ozlabs.ibm.com> <73CD5806-5CE4-40A7-957B-8F164E26FAFB@kernel.crashing.org> <18455.59014.305281.949578@cargo.ozlabs.ibm.com> Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Apr 29, 2008, at 10:24 PM, Paul Mackerras wrote: > Kumar Gala writes: > >>> Wouldn't it be better and safer to have the exception prolog for >>> critical interrupts save SRR0/1 in the stack frame, and have the >>> prolog for machine checks save SRR0/1 and CSRR0/1 likewise? >> >> If we do this I guess we can use SRR0/1 regardless of which level we >> came from. > > That's the idea. I actually thought the booke exception prologs > already did that, but it seems I'm wrong. > > What sort of things do you expect critical and machine-check handlers > to be needing to do? It varies on the parts but remember critical level can be anything from watchdog, critical input (equivalent of external input, but at the critical level), and debug. So there is a pretty wide set of possibility. - k