[src/trunk]: src/sys/arch/sparc64/sparc64 sun4v: added some missing comments ...

[palle <palle%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7915be9a79a6
branches:  trunk
changeset: 1000269:7915be9a79a6
user:      palle <palle%NetBSD.org@localhost>
date:      Thu Jul 18 18:21:45 2019 +0000

description:
sun4v: added some missing comments to the code in pcbspill

diffstat:

 sys/arch/sparc64/sparc64/locore.s |  14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

diffs (35 lines):

diff -r 3a1df60d2d20 -r 7915be9a79a6 sys/arch/sparc64/sparc64/locore.s
--- a/sys/arch/sparc64/sparc64/locore.s Thu Jul 18 12:04:16 2019 +0000
+++ b/sys/arch/sparc64/sparc64/locore.s Thu Jul 18 18:21:45 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: locore.s,v 1.420 2019/04/07 19:31:38 mrg Exp $ */
+/*     $NetBSD: locore.s,v 1.421 2019/07/18 18:21:45 palle Exp $       */
 
 /*
  * Copyright (c) 2006-2010 Matthew R. Green
@@ -3463,11 +3463,11 @@
        or      %g7, %g6, %g6                           ! Then combine them to form PA
 
        wr      %g0, ASI_PHYS_CACHED, %asi              ! Use ASI_PHYS_CACHED to prevent possible page faults
-       
-       lduba   [%g6 + PCB_NSAVED] %asi, %g7
-       sllx    %g7, 7, %g5
-       add     %g6, %g5, %g5
-       SPILL   stxa, %g5 + PCB_RW, 8, %asi
+
+       lduba   [%g6 + PCB_NSAVED] %asi, %g7            ! Fetch current nsaved from the pcb
+       sllx    %g7, 7, %g5                             ! 8+8 registers each 8 bytes = 128 bytes (2^7)
+       add     %g6, %g5, %g5                           ! Offset into pcb_rw
+       SPILL   stxa, %g5 + PCB_RW, 8, %asi             ! Store the locals and ins 
        saved
 
        sllx    %g7, 3, %g5
@@ -5089,7 +5089,7 @@
         * to exceede the maximum trap level on sun4v, so a manual fill
         * may be necessary.
        */
-       
+
 #ifdef SUN4V
        sethi   %hi(cputyp), %g5
        ld      [%g5 + %lo(cputyp)], %g5