svn commit: r346619 - head/sys/powerpc/aim

[Justin Hibbits]

Author: jhibbits
Date: Wed Apr 24 02:51:58 2019
New Revision: 346619
URL: https://svnweb.freebsd.org/changeset/base/346619

Log:
  powerpc: Add a couple missing isyncs
  
  mtmsr and mtsr require context synchronizing instructions to follow.  Without
  a CSI, there's a chance for a machine check exception.  This reportedly does
  occur on a MPC750 (PowerMac G3).
  
  Reported by:	Mark Millard

Modified:
  head/sys/powerpc/aim/trap_subr32.S

Modified: head/sys/powerpc/aim/trap_subr32.S
==============================================================================
--- head/sys/powerpc/aim/trap_subr32.S	Wed Apr 24 01:11:50 2019	(r346618)
+++ head/sys/powerpc/aim/trap_subr32.S	Wed Apr 24 02:51:58 2019	(r346619)
@@ -68,7 +68,7 @@
 	lwzu	sr,PM_SR(pmap); \
 	RESTORE_SRS(pmap,sr) \
 	/* Restore SR 12 */ \
-	lwz	sr,12*4(pmap);	mtsr	12,sr
+	lwz	sr,12*4(pmap);	mtsr	12,sr; isync
 
 /*
  * Kernel SRs are loaded directly from kernel_pmap_
@@ -799,6 +799,7 @@ CNAME(trapexit):
 	mfmsr	%r3
 	andi.	%r3,%r3,~PSL_EE at l
 	mtmsr	%r3
+	isync
 /* Test AST pending: */
 	lwz	%r5,FRAME_SRR1+8(%r1)
 	mtcr	%r5