kern/58340: 64-bit atomic ops unusable for armv7: __HAVE_ATOMIC64_{OPS,LOADSTORE} confusion

[rokuyama.rk%gmail.com@localhost]

>Number:         58340
>Category:       kern
>Synopsis:       64-bit atomic ops unusable for armv7: __HAVE_ATOMIC64_{OPS,LOADSTORE} confusion
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jun 13 02:15:00 +0000 2024
>Originator:     Rin Okuyama
>Release:        10.99.10 and 10.0
>Organization:
Internet Initiative Japan Inc.
>Environment:
NetBSD console 10.99.10 NetBSD 10.99.10 (SUNXI_NET_MPSAFE) #1: Thu Feb  8 23:00:33 JST 2024  rin@sakaizumii.local:/home/rin/src/sys/arch/evbarm/compile/SUNXI_NET_MPSAFE evbarm earmv7hfeb
>Description:
64-bit atomic ops provided by <sys/atomic.h> cannot be used for
armv7, even though __HAVE_ATOMIC64_OPS is defined for its
<machine/types.h>.

This is because for <sys/atomic.h>,
(1) __HAVE_ATOMIC64_LOADSTORE is defined ifdef _LP64, and
(2) 64-bit atomic ops are provided ifdef __HAVE_ATOMIC64_LOADSTORE.
>How-To-Repeat:
Try to use atomic_{load,store}_*(9) for armv7 kernel.
>Fix:
Check __HAVE_ATOMIC64_OPS, instead _LP64 for <sys/atomic.h>?
But, do we still need __HAVE_ATOMIC64_LOADSTORE?

diff --git a/sys/sys/atomic.h b/sys/sys/atomic.h
index 6c8af6d531e..fa92a7c3934 100644
--- a/sys/sys/atomic.h
+++ b/sys/sys/atomic.h
@@ -399,7 +399,9 @@ __END_DECLS
 
 #include <lib/libkern/libkern.h>
 
-#ifdef _LP64
+#include <machine/types.h>
+
+#ifdef __HAVE_ATOMIC64_OPS
 #define	__HAVE_ATOMIC64_LOADSTORE	1
 #define	__ATOMIC_SIZE_MAX		8
 #else