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


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


unsigned long base

Physical base address

unsigned long size

Size of region


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.

The called should provide a power of two size on an equivalent power of two boundary.

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