From mboxrd@z Thu Jan 1 00:00:00 1970 From: William Lee Irwin III Date: Wed, 12 Jan 2005 05:38:49 +0000 Subject: Re: Current BK kernel error Message-Id: <20050112053849.GE14443@holomorphy.com> List-Id: References: <20050111143605.GC4514@artsapartment.org> In-Reply-To: <20050111143605.GC4514@artsapartment.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: sparclinux@vger.kernel.org William Lee Irwin III wrote: >> According to Bob Breuer, returning 1 always seems to work for ordinary >> userspace (as opposed to "unusual" programs). I've got documentation, >> so I'll brew up something more accurate for it over the weekend. On Tue, Jan 11, 2005 at 10:02:58PM -0600, Bob Breuer wrote: > Yes, the easy way out is to return 1 from pte_read. To do it right we will > need a combined solution for sun4c and sun4m. I think that sun4 can use > the sun4c version and sun4d will share with sun4m. > For sun4c, we can use the software managed read bit: > return pte_val(pte) & _SUN4C_PAGE_READ; > I can't test this myself, but it mirrors the pte_write functionality. > For sun4m, there is no software bit for read, so we peek at the hardware > ACC field from the pte: > return !(pte_val(pte) & 0x10); > We need a #define to go with the new usage of this bit, maybe SRMMU_NOREAD? > I have tested the sun4m solution on my SS20 and it works for me. > Now, how can these be combined using the btfixup magic? Ship me what you've got and I'll test it on sun4c and BTFIXUP-ize it. -- wli