d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
2a4fd6b17a
freebsd-dev/sys/i386
History
Konstantin Belousov af95bbf5bf Intel SDM before revision 56 described the CLFLUSH instruction as only 
ordered with the MFENCE instruction.  Similar weak guarantees are also
specified by the AMD APM vol. 3 rev. 3.22.  x86 pmap methods
pmap_invalidate_cache_range() and pmap_invalidate_cache_pages() braced
CLFLUSH loop with MFENCE both before and after the loop.

In the revision 56 of SDM, Intel stated that all existing
implementations of CLFLUSH are strict, CLFLUSH instructions execution
is ordered WRT other CLFLUSH and writes.  Also, the strict behaviour
is made architectural.

A new instruction CLFLUSHOPT (which was documented for some time in
the Instruction Set Extensions Programming Reference) provides the
weak behaviour which was previously attributed to CLFLUSH.

Use CLFLUSHOPT when available.  When CLFLUSH is used on Intel CPUs, do
not execute MFENCE before and after the flushing loop.

Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
2015-10-24 21:37:47 +00:00
..
acpica If x86 CPU implementation of the MWAIT instruction reasonably 2015-05-09 12:28:48 +00:00
bios Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
conf Remove compatibility shims for legacy ATA device names. 2015-10-11 13:01:51 +00:00
i386 Intel SDM before revision 56 described the CLFLUSH instruction as only 2015-10-24 21:37:47 +00:00
ibcs2 Replace struct filedesc argument in getvnode with struct thread 2015-06-16 13:09:18 +00:00
include Add CLFLUSHOPT instruction wrappers. 2015-10-23 11:45:38 +00:00
isa Convert between abridged (from FXSAVE) and unabridged (from FSAVE) 2015-07-10 09:20:13 +00:00
linux Fix missing semi-colon from r289055. 2015-10-08 23:27:45 +00:00
pci Remove support for Xen PV domU kernels. Support for HVM domU kernels 2015-04-30 15:48:48 +00:00
svr4 MFamd64: Move extern declaration of _ucodesel and _udatasel to 2014-11-02 21:40:32 +00:00
xbox After r261980, the local ptr variable in xbox_init() is no longer used, 2014-02-16 22:48:36 +00:00
Makefile Delete duplicate tags entry I introduced in -r223901. 2011-07-15 17:27:26 +00:00