- Add support to atomically set/clear individual bits of a MSR register

  via cpuctl(4) driver.  Two new CPUCTL_MSRSBIT and CPUCTL_MSRCBIT ioctl(2)
  calls treat the data field of the argument struct passed as a mask
  and set/clear bits of the MSR register according to the mask value.
- Allow user to perform atomic bitwise AND and OR operaions on MSR registers
  via cpucontrol(8) utility.  Two new operations ("&=" and "|=") have been
  added.  The first one applies bitwise AND operaion between the current
  contents of the MSR register and the mask, and the second performs bitwise
  OR.  The argument can be optionally prefixed with "~" inversion operator.
  This allows one to mimic the "clear bit" behavior by using the command
  like this:
      cpucontrol -m 0x10&=~0x02		# clear the second bit of TSC MSR

  Inversion operator support in all modes (assignment, OR, AND).

Approved by:	re (kib)
MFC after:	1 month

1 files changed, 6 insertions, 1 deletions

diff --git a/share/man/man4/cpuctl.4 b/share/man/man4/cpuctl.4
index 9dd149a..09b2d4e 100644
--- a/share/man/man4/cpuctl.4
+++ b/share/man/man4/cpuctl.4
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 31, 2008
+.Dd June 30, 2009
 .Dt CPUCTL 4
 .Os
 .Sh NAME
@@ -81,6 +81,11 @@ typedef struct {
 	uint64_t	data;
 } cpuctl_msr_args_t;
 .Ed
+.It Dv CPUCTL_MSRSBIT Fa cpuctl_msr_args_t *args
+.It Dv CPUCTL_MSRCBIT Fa cpuctl_msr_args_t *args
+Set/clear MSR bits according to the mask given in the
+.Va data
+field.
 .It Dv CPUCTL_CPUID Fa cpuctl_cpuid_args_t *args
 Retrieve CPUID information.
 Arguments are supplied in