diff options
| -rw-r--r-- | lib/libarch/amd64/amd64_get_mtrr.2 | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/lib/libarch/amd64/amd64_get_mtrr.2 b/lib/libarch/amd64/amd64_get_mtrr.2 index 05104c99e60..58a75dd9d7b 100644 --- a/lib/libarch/amd64/amd64_get_mtrr.2 +++ b/lib/libarch/amd64/amd64_get_mtrr.2 @@ -57,12 +57,14 @@ on .Xr pci 4 and .Xr agp 4 -busses. For example, enabling write-combining allows bus-write transfers -to be combined into a larger transfer before bursting over the bus. This -can increase performance of write operations 2.5 times or more. +busses. +For example, enabling write-combining allows bus-write transfers +to be combined into a larger transfer before bursting over the bus. +This can increase performance of write operations 2.5 times or more. .Pp .Fa mtrrp -is a pointer to one or more mtrr structures, as described below. The +is a pointer to one or more mtrr structures, as described below. +The .Fa n argument is a pointer to an integer containing the number of structures pointed to by @@ -135,19 +137,20 @@ entry is valid .Pp The .Em owner -member the PID of the user process which claims the mapping. It is -only valid if MTRR_PRIVATE is set in +member is the PID of the user process which claims the mapping. +It is only valid if MTRR_PRIVATE is set in .Em flags . To clear/reset MTRRs, use a .Em flags field without MTRR_VALID set. .Sh RETURN VALUES -Upon successful completion zero is returned, otherwise -1 is returned +Upon successful completion zero is returned, otherwise \-1 is returned on failure, and the global variable .Va errno -is set to indicate the error. The integer value pointed to by +is set to indicate the error. +The integer value pointed to by .Fa n -will be container the number of successfully processed mtrr structures +will contain the number of successfully processed mtrr structures in both cases. .Sh ERRORS .Bl -tag -width [EINVAL] |