centos man page for arch_phys_wc_add

ARCH_PHYS_WC_ADD(9)						Hardware Interfaces					       ARCH_PHYS_WC_ADD(9)

NAME
       arch_phys_wc_add - add a WC MTRR and handle errors if PAT is unavailable

SYNOPSIS
       int arch_phys_wc_add(unsigned long base, unsigned long size);

ARGUMENTS
       base
	   Physical base address

       size
	   Size of region

DESCRIPTION
       If PAT is available, this does nothing. If PAT is unavailable, it attempts to add a WC MTRR covering size bytes starting at base and logs
       an error if this fails.

       Drivers must store the return value to pass to mtrr_del_wc_if_needed, but drivers should not try to interpret that return value.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						       ARCH_PHYS_WC_ADD(9)