From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mundt Date: Tue, 15 Sep 2009 11:57:18 +0000 Subject: Re: User mode address error problems on 7763 Message-Id: <20090915115717.GA22736@linux-sh.org> List-Id: References: <6e6aa1a80909111106l6dbcfccag4e9e7a3abb922688@mail.gmail.com> In-Reply-To: <6e6aa1a80909111106l6dbcfccag4e9e7a3abb922688@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sh@vger.kernel.org On Tue, Sep 15, 2009 at 06:54:35AM -0500, Dale Larson wrote: > On Tue, Sep 15, 2009 at 3:39 AM, Matt Fleming wrote: > > OK, these are unexpected fixups and similar to the issues I've been > > seeing. The current train of thought is that these unaligned accesses > > are a symptom of having aliases in the D-cache. I've been trawling > > through the cache/tlb code for SH4 and so far haven't found the bug. > > > > As a little experiment, could you try bumping the page size from 4K to > > 8K and see if the unaligned accesses go away? If they are caused by > > D-cache aliasing, in theory, they should disappear with 8K pages. > > The 7763 only supports 1K, 4K, 64K and 1M pages. Would a 64K page > yield any useful info? > You can get 8kB pages by enabling extended mode TLB. But yes, 64k pages are fine too, if using the compat mode TLB.