pc, xen: make PAT support optional (for xen)

2020-05-31 14:32:19 +02:00 · 2020-05-31 14:32:19 +02:00 · 30bf1c45ca
parent 5cd7f7b0ec
commit 30bf1c45ca
1 changed files with 2 additions and 0 deletions
--- a/sys/src/9/pc/devarch.c
+++ b/sys/src/9/pc/devarch.c
@ -882,12 +882,14 @@ cpuidentify(void)
 			rdmsr(0x01, &mct);
 	}

+#ifdef PATWC
 	/* IA32_PAT write combining */
 	if((m->cpuiddx & Pat) != 0 && rdmsr(0x277, &pat) != -1){
 		pat &= ~(255LL<<(PATWC*8));
 		pat |= 1LL<<(PATWC*8);	/* WC */
 		wrmsr(0x277, pat);
 	}
+#endif

 	if(m->cpuiddx & Mtrr)
 		mtrrsync();