From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v2 11/15] xen/arm: vgic-v2: Correctly handle RAZ/WI registers Date: Tue, 03 Feb 2015 13:14:00 +0000 Message-ID: <54D0C998.7020006@linaro.org> References: <1422555950-31821-1-git-send-email-julien.grall@linaro.org> <1422555950-31821-12-git-send-email-julien.grall@linaro.org> <1422892959.5838.23.camel@citrix.com> <54CFA774.3010904@linaro.org> <1422895851.5838.34.camel@citrix.com> <54CFAF0D.7090403@linaro.org> <1422898891.9323.6.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1YIdJG-0005Wo-9X for xen-devel@lists.xenproject.org; Tue, 03 Feb 2015 13:14:30 +0000 Received: by mail-wg0-f47.google.com with SMTP id n12so44553068wgh.6 for ; Tue, 03 Feb 2015 05:14:28 -0800 (PST) In-Reply-To: <1422898891.9323.6.camel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: xen-devel@lists.xenproject.org, Vijaya.Kumar@caviumnetworks.com, tim@xen.org, stefano.stabellini@citrix.com List-Id: xen-devel@lists.xenproject.org On 02/02/15 17:41, Ian Campbell wrote: > On Mon, 2015-02-02 at 17:08 +0000, Julien Grall wrote: >> On 02/02/15 16:50, Ian Campbell wrote: >>> On Mon, 2015-02-02 at 16:36 +0000, Julien Grall wrote: >>>> Hi Ian, >>>> >>>> On 02/02/15 16:02, Ian Campbell wrote: >>>>> On Thu, 2015-01-29 at 18:25 +0000, Julien Grall wrote: >>>>>> Some of the registers are accessible via multiple size (see GICD_IPRIORITYR*). >>>>> >>>>> They are byte accessible, but are they half word accessible? I suspect >>>>> not. >>>> >>>> Only byte accessible. >>> >>> I think we might need a read_as_zero_8_32 then, i.e. explicitly list the >>> sizes which are allowed, and perhaps omit the un-suffixed version for so >>> it's clear exactly what is what, although that might be more churn than >>> you want to have here. >> >> Hmmm, why? I was talking for registers defined in the spec. We don't >> know if reserved/implementation defined registers will allow half-word >> access. >> >> The un-suffixed version is there when we don't need to check the size >> because it has already been done. It seems pointless to check it again. > > I'd forgotten the existing check was there, yes it does make sense to > use it in this case. Shall I clarify the commit message for this bit? Regards, -- Julien Grall