From owner-cvs-src-old@FreeBSD.ORG Sat May 14 21:03:58 2011 Return-Path: Delivered-To: cvs-src-old@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 078901065670 for ; Sat, 14 May 2011 21:03:58 +0000 (UTC) (envelope-from marius@FreeBSD.org) Received: from repoman.freebsd.org (repoman.freebsd.org [IPv6:2001:4f8:fff6::29]) by mx1.freebsd.org (Postfix) with ESMTP id CDC068FC08 for ; Sat, 14 May 2011 21:03:57 +0000 (UTC) Received: from repoman.freebsd.org (localhost [127.0.0.1]) by repoman.freebsd.org (8.14.4/8.14.4) with ESMTP id p4EL3vvb017179 for ; Sat, 14 May 2011 21:03:57 GMT (envelope-from marius@repoman.freebsd.org) Received: (from svn2cvs@localhost) by repoman.freebsd.org (8.14.4/8.14.4/Submit) id p4EL3vnR017178 for cvs-src-old@freebsd.org; Sat, 14 May 2011 21:03:57 GMT (envelope-from marius@repoman.freebsd.org) Message-Id: <201105142103.p4EL3vnR017178@repoman.freebsd.org> X-Authentication-Warning: repoman.freebsd.org: svn2cvs set sender to marius@repoman.freebsd.org using -f From: Marius Strobl Date: Sat, 14 May 2011 21:03:44 +0000 (UTC) To: cvs-src-old@freebsd.org X-FreeBSD-CVS-Branch: RELENG_8 Subject: cvs commit: src/sys/sparc64/include pmap.h tsb.h src/sys/sparc64/sparc64 exception.S genassym.c mp_machdep.c pmap.c tsb.c X-BeenThere: cvs-src-old@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: **OBSOLETE** CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 14 May 2011 21:03:58 -0000 marius 2011-05-14 21:03:44 UTC FreeBSD src repository Modified files: (Branch: RELENG_8) sys/sparc64/include pmap.h tsb.h sys/sparc64/sparc64 exception.S genassym.c mp_machdep.c pmap.c tsb.c Log: SVN rev 221918 on 2011-05-14 21:03:44Z by marius MFC: r216803, r217058, r217514, r218457 On UltraSPARC-III+ and greater take advantage of ASI_ATOMIC_QUAD_LDD_PHYS, which takes an physical address instead of an virtual one, for loading TTEs of the kernel TSB so we no longer need to lock the kernel TSB into the dTLB, which only has a very limited number of lockable dTLB slots. The net result is that we now basically can handle a kernel TSB of any size and no longer need to limit the kernel address space based on the number of dTLB slots available for locked entries. Consequently, other parts of the trap handlers now also only access the the kernel TSB via its physical address in order to avoid nested traps, as does the PMAP bootstrap code as we haven't taken over the trap table at that point, yet. Apart from that the kernel TSB now is accessed via a direct mapping when we are otherwise taking advantage of ASI_ATOMIC_QUAD_LDD_PHYS so no further code changes are needed. Most of this is implemented by extending the patching of the TSB addresses and mask as well as the ASIs used to load it into the trap table so the runtime overhead of this change is rather low. Theoretically it should be possible to use the same approach also for the user TSB, which already is not locked into the dTLB, avoiding nested traps. However, for reasons I don't understand yet OpenSolaris only does that with SPARC64 CPUs. On the other hand I think that also addressing the user TSB physically and thus avoiding nested traps would get us closer to sharing this code with sun4v, which only supports trap level 0 and 1, so eventually we could have a single kernel which runs on both sun4u and sun4v (as does Linux and OpenBSD). Revision Changes Path 1.49.2.4 +5 -4 src/sys/sparc64/include/pmap.h 1.19.10.2 +1 -0 src/sys/sparc64/include/tsb.h 1.80.2.4 +119 -38 src/sys/sparc64/sparc64/exception.S 1.76.2.6 +1 -0 src/sys/sparc64/sparc64/genassym.c 1.52.2.11 +7 -2 src/sys/sparc64/sparc64/mp_machdep.c 1.182.2.13 +200 -72 src/sys/sparc64/sparc64/pmap.c 1.40.2.3 +5 -2 src/sys/sparc64/sparc64/tsb.c