ref: 3c879559eaa8add9258ecd6383c1cf0c3ebccb63
parent: 9dee44064a338d305241e4599d8c2e085c364317
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Sun May 31 10:32:19 EDT 2020
pc, xen: make PAT support optional (for xen)
--- a/sys/src/9/pc/devarch.c
+++ b/sys/src/9/pc/devarch.c
@@ -882,6 +882,7 @@
rdmsr(0x01, &mct);
}
+#ifdef PATWC
/* IA32_PAT write combining */
if((m->cpuiddx & Pat) != 0 && rdmsr(0x277, &pat) != -1){pat &= ~(255LL<<(PATWC*8));
@@ -888,6 +889,7 @@
pat |= 1LL<<(PATWC*8); /* WC */
wrmsr(0x277, pat);
}
+#endif
if(m->cpuiddx & Mtrr)
mtrrsync();
--
⑨