From 24b08bca030970592bc5241517b0462f603b05b1 Mon Sep 17 00:00:00 2001
From: jkim <jkim@FreeBSD.org>
Date: Wed, 22 Dec 2010 00:18:42 +0000
Subject: Improve PCB flags handling and make it more robust.  Add two new
 functions for manipulating pcb_flags.  These inline functions are very
 similar to atomic_set_char(9) and atomic_clear_char(9) but without
 unnecessary LOCK prefix for SMP.  Add comments about the rationale[1].  Use
 these functions wherever possible.  Although there are some places where it
 is not strictly necessary (e.g., a PCB is copied to create a new PCB), it is
 done across the board for sake of consistency.  Turn pcb_full_iret into a PCB
 flag as it is safe now.  Move rarely used fields before pcb_flags and reduce
 size of pcb_flags to one byte.  Fix some style(9) nits in pcb.h while I am in
 the neighborhood.

Reviewed by:	kib
Submitted by:	kib[1]
MFC after:	2 months
---
 sys/amd64/amd64/exception.S | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

(limited to 'sys/amd64/amd64/exception.S')

diff --git a/sys/amd64/amd64/exception.S b/sys/amd64/amd64/exception.S
index 7ffa7a9..2d6f97a 100644
--- a/sys/amd64/amd64/exception.S
+++ b/sys/amd64/amd64/exception.S
@@ -170,7 +170,7 @@ alltraps:
 	jz	alltraps_testi		/* already running with kernel GS.base */
 	swapgs
 	movq	PCPU(CURPCB),%rdi
-	movb	$0,PCB_FULL_IRET(%rdi)
+	andb	$~PCB_FULL_IRET,PCB_FLAGS(%rdi)
 	movw	%fs,TF_FS(%rsp)
 	movw	%gs,TF_GS(%rsp)
 	movw	%es,TF_ES(%rsp)
@@ -243,7 +243,7 @@ alltraps_noen:
 	jz	1f	/* already running with kernel GS.base */
 	swapgs
 	movq	PCPU(CURPCB),%rdi
-	movb	$0,PCB_FULL_IRET(%rdi)
+	andb	$~PCB_FULL_IRET,PCB_FLAGS(%rdi)
 1:	movw	%fs,TF_FS(%rsp)
 	movw	%gs,TF_GS(%rsp)
 	movw	%es,TF_ES(%rsp)
@@ -294,7 +294,7 @@ IDTVEC(page)
 	jz	1f			/* already running with kernel GS.base */
 	swapgs
 	movq	PCPU(CURPCB),%rdi
-	movb	$0,PCB_FULL_IRET(%rdi)
+	andb	$~PCB_FULL_IRET,PCB_FLAGS(%rdi)
 1:	movq	%cr2,%rdi		/* preserve %cr2 before ..  */
 	movq	%rdi,TF_ADDR(%rsp)	/* enabling interrupts. */
 	movw	%fs,TF_FS(%rsp)
@@ -324,7 +324,7 @@ IDTVEC(prot)
 	jz	2f			/* already running with kernel GS.base */
 1:	swapgs
 2:	movq	PCPU(CURPCB),%rdi
-	movb	$1,PCB_FULL_IRET(%rdi)	/* always full iret from GPF */
+	orb	$PCB_FULL_IRET,PCB_FLAGS(%rdi)	/* always full iret from GPF */
 	movw	%fs,TF_FS(%rsp)
 	movw	%gs,TF_GS(%rsp)
 	movw	%es,TF_ES(%rsp)
@@ -356,7 +356,7 @@ IDTVEC(fast_syscall)
 	movw	%es,TF_ES(%rsp)
 	movw	%ds,TF_DS(%rsp)
 	movq	PCPU(CURPCB),%r11
-	movb	$0,PCB_FULL_IRET(%r11)
+	andb	$~PCB_FULL_IRET,PCB_FLAGS(%r11)
 	sti
 	movq	$KUDSEL,TF_SS(%rsp)
 	movq	$KUCSEL,TF_CS(%rsp)
@@ -661,8 +661,8 @@ doreti_exit:
 	 */
 	testb	$SEL_RPL_MASK,TF_CS(%rsp)
 	jz	ld_regs
-	cmpb	$0,PCB_FULL_IRET(%r8)
-	je	ld_regs
+	testb	$PCB_FULL_IRET,PCB_FLAGS(%r8)
+	jz	ld_regs
 	testl	$TF_HASSEGS,TF_FLAGS(%rsp)
 	je	set_segs
 
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