---
name: "arch_phys_wc_add"
section: "9"
platform: "linux"
package: "linux-manual-4.9"
version: "4.9.228-1"
release: "Debian 9 (Stretch)"
platforms: ["linux"]
url: "https://new.carta.tech/arch_phys_wc_add"
---

# arch\_phys\_wc\_add(9)

add a WC MTRR and handle errors if PAT is unavailable

## 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.

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.

## COPYRIGHT