git: aa4736459ee2 - main - powerpc/atomic: Fix atomic_testand_*_long on powerpc64

From: Justin Hibbits <jhibbits_at_FreeBSD.org>
Date: Thu, 03 Feb 2022 23:25:49 UTC
The branch main has been updated by jhibbits:

URL: https://cgit.FreeBSD.org/src/commit/?id=aa4736459ee2d314dc90ae9cbb4ad9c1cf48d796

commit aa4736459ee2d314dc90ae9cbb4ad9c1cf48d796
Author:     Justin Hibbits <jhibbits@FreeBSD.org>
AuthorDate: 2022-02-03 23:20:36 +0000
Commit:     Justin Hibbits <jhibbits@FreeBSD.org>
CommitDate: 2022-02-03 23:25:39 +0000

    powerpc/atomic: Fix atomic_testand_*_long on powerpc64
    
    After b5d227b0 FreeBSD was panicking on boot with "Duplicate free" in
    UMA.  Analyzing the asm, the '1' mask was treated as an integer, rather
    than a long, causing 'slw' (shift left word) to be used for the shifting
    instruction, not 'sld' (shift left double).  This means the upper bits
    of the bitfield were not getting used, resulting in corruption of the
    bitfield.
    
    While fixing this, the 'and' check of the mask does not need to be
    recorded, so don't record (drop the '.').
---
 sys/powerpc/include/atomic.h | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/sys/powerpc/include/atomic.h b/sys/powerpc/include/atomic.h
index deb53173418f..43bb239719ae 100644
--- a/sys/powerpc/include/atomic.h
+++ b/sys/powerpc/include/atomic.h
@@ -997,13 +997,13 @@ atomic_swap_64(volatile u_long *p, u_long v)
 static __inline int
 atomic_testandset_int(volatile u_int *p, u_int v)
 {
-	u_int m = (1 << (v & 0x1f));
+	u_int m = (1u << (v & 0x1f));
 	u_int res;
 	u_int tmp;
 
 	__asm __volatile(
 	"1:	lwarx	%0,0,%3\n"
-	"	and.	%1,%0,%4\n"
+	"	and	%1,%0,%4\n"
 	"	or	%0,%0,%4\n"
 	"	stwcx.	%0,0,%3\n"
 	"	bne-	1b\n"
@@ -1017,13 +1017,13 @@ atomic_testandset_int(volatile u_int *p, u_int v)
 static __inline int
 atomic_testandclear_int(volatile u_int *p, u_int v)
 {
-	u_int m = (1 << (v & 0x1f));
+	u_int m = (1u << (v & 0x1f));
 	u_int res;
 	u_int tmp;
 
 	__asm __volatile(
 	"1:	lwarx	%0,0,%3\n"
-	"	and.	%1,%0,%4\n"
+	"	and	%1,%0,%4\n"
 	"	andc	%0,%0,%4\n"
 	"	stwcx.	%0,0,%3\n"
 	"	bne-	1b\n"
@@ -1038,13 +1038,13 @@ atomic_testandclear_int(volatile u_int *p, u_int v)
 static __inline int
 atomic_testandset_long(volatile u_long *p, u_int v)
 {
-	u_long m = (1 << (v & 0x3f));
+	u_long m = (1ul << (v & 0x3f));
 	u_long res;
 	u_long tmp;
 
 	__asm __volatile(
 	"1:	ldarx	%0,0,%3\n"
-	"	and.	%1,%0,%4\n"
+	"	and	%1,%0,%4\n"
 	"	or	%0,%0,%4\n"
 	"	stdcx.	%0,0,%3\n"
 	"	bne-	1b\n"
@@ -1058,13 +1058,13 @@ atomic_testandset_long(volatile u_long *p, u_int v)
 static __inline int
 atomic_testandclear_long(volatile u_long *p, u_int v)
 {
-	u_long m = (1 << (v & 0x3f));
+	u_long m = (1ul << (v & 0x3f));
 	u_long res;
 	u_long tmp;
 
 	__asm __volatile(
 	"1:	ldarx	%0,0,%3\n"
-	"	and.	%1,%0,%4\n"
+	"	and	%1,%0,%4\n"
 	"	andc	%0,%0,%4\n"
 	"	stdcx.	%0,0,%3\n"
 	"	bne-	1b\n"