From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: To: Thomas Bogendoerfer Cc: parisc-linux@lists.parisc-linux.org Subject: Re: [parisc-linux] FB on c3k In-Reply-To: Message from Thomas Bogendoerfer of "Thu, 07 Mar 2002 11:03:39 +0100." <20020307110339.A1590@solo.franken.de> References: <20020306080101.B6A874859@dsl2.external.hp.com> <20020307002239.A9224@solo.franken.de> <20020307073117.4C572482F@dsl2.external.hp.com> <20020307110339.A1590@solo.franken.de> Date: Sat, 09 Mar 2002 23:56:41 -0700 From: Grant Grundler Message-Id: <20020310065641.D8D3A48EB@dsl2.external.hp.com> Sender: parisc-linux-admin@lists.parisc-linux.org Errors-To: parisc-linux-admin@lists.parisc-linux.org List-Help: List-Post: List-Subscribe: , List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: Thomas Bogendoerfer wrote: > after sleeping over the problem, I believe we were short just one bit. > We extracted 32 bits from the PTE. The lower 5 bits are zeroed and will > be the 4 size bits and the one 0 bit in the TLB. That leaves 27 bits for > the physical page number. Adding the 12 offset bits for 4k pages gives us > just 39 bits, but we need 40. So instead of the change 32 -> 52 a > change from 32 -> 33 should do the same. On the other side using all > bits shouldn't matter and we are prepared for 44 bit and more. ok. that all make sense now. It made more sense when I read about extru and idtlbt in the PA 2.0 Arch book. > BTW. > isn't our current PDC space expansion wrong for "odd" sized address > spaces ? It should work for 48 and 56, but not for anything else. > Or do I miss something ? I have no clue. jsm or willy know? > I will have a J6700 at Cebit to play with, but I don't think I'll > get spare time in the next couple of days. Done! See ftp://ftp.p-l.o/patches/entry.S-diff The 32-bit kernel with FB is working with 4 instances of the following change to entry.S (all immediately preceed an idtlbt instruction): - extrd,u pte,56,25,pte + extrd,s pte,56,25,pte /* bit 31:8 >> 8 */ + depdi 0,3,4,pte /* page_size = 4k (in case signed) */ CAVEAT: This is better than the brokeness we had before. But it doesn't properly handle 0xf0xxxxxx addresses. Those need to be "f-extended" with 0xf0f0f0... instead of all 1's. > yes, with your last ioctl32 changes. I need to recheck my first entry.S > hack for the narrow mode pa2.0 tlb handler. I think my assembler code > just sucks and setting up the tlbs the same way as for wide mode, > should get us X with 32-bit kernels, too. Done. patch on ftp.p-l.o/patches/entry.S-diff. Can someone with VM cluefulness review this for me? It seems to be working on my c3k with Vis-EG/PCI now though...wohoo! :^) thanks, grant