-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello,
On Aug 13, 2009, at 2:28 AM, Matt Turner wrote: > On Thu, Aug 13, 2009 at 1:51 AM, David Miller<[email protected]> > wrote: >> From: Matt Turner <[email protected]> >> Date: Thu, 13 Aug 2009 01:45:39 -0400 >> >>> Cc: David S. Miller <[email protected]> >>> Cc: Alan Coopersmith <[email protected]> >>> Signed-off-by: Matt Turner <[email protected]> >> >> This breaks 32-bit sparc. >> >> It will cause the binaries built to be tagged as needing v8plus or v9 >> instructions. They therefore won't execute or load on a 32-bit sparc >> system. >> >> That's why I encoded the membars using explicit instruction >> constants, >> rather than using the usual mnemonics. > > Surely gcc defines a macro we can check for? Something like __sparcv9 > or __arch64__? What is preferred? __arch64__ doesn't cut it - a 64bit SPARC isn't guaranteed to run in 64bit mode. I think gcc defines __sparcv9__ when the target allows v9 instructions ( and v8plus is more or less v9 running with 32bit pointers but otherwise full access to v9 instructions IIRC ) > I wanted to do something like this, but I wasn't sure if (1) we needed > to worry about 32-bit sparc or NetBSD/sparc 5.0 ships with Xorg 1.4.2, I have 1.6.something working on -current. I'm sure OpenBSD and Linux do the same. > On another note, are load barriers not needed for in{b,w,l} and > xf86ReadMmio* functions? Usually SBus, PCI and UPA accesses on sparc are uncached and strongly ordered. I'm not quite sure if that's 100% guaranteed though, and there are graphics devices on sparc which are neither - they can put barriers in their drivers when needed though. As far as I can tell no SBus or UPA driver in Xorg uses any barrier macros. Only xf86-video- sunffb uses membar #sync but there's no way you can get any of those in a 32bit sparc. have fun Michael -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (Darwin) iQEVAwUBSoO4YMpnzkX8Yg2nAQJr+gf/SewXKKySBhGTcRmGCes+dhHJS1SjjAzr MEa6p4I35BrX0ZV4aQiSm7aPLoSXKGOV319jsDC/9hbeHpRqpjyezGgKLxPowKyt bem+EuqWDEkFq0Iy3WEwC4UU1KeYELzorlYO9Tuww0SCusvW2845vqrLEV+nSEHz F+egUmEGHVscuXV1BCmlsqLmNi6JQtqaEARtXLoO5NXdds6PhB6au4+5WngV2Xj5 VewRa/hVRe6II++tiJBxNB47WkLLbhuFMNMQBiMdhyJvRFC2vR6AwFIwIiDDPilu /hh5G5H0zx36Uup9pyvS3FeTuTrlsFkescTAZfaVS6yX6EIR6DrMiA== =UHH4 -----END PGP SIGNATURE----- _______________________________________________ xorg-devel mailing list [email protected] http://lists.x.org/mailman/listinfo/xorg-devel
