From 510ed7dff71505920e0319c2522f624b411a3791 Mon Sep 17 00:00:00 2001 From: Taylor R Campbell Date: Thu, 31 Mar 2022 02:13:23 +0000 Subject: [PATCH 26/49] linux/kref: Fix memory barriers and use membar_release/acquire. --- sys/external/bsd/drm2/include/linux/kref.h | 23 +++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/sys/external/bsd/drm2/include/linux/kref.h b/sys/external/bsd/drm2/include/linux/kref.h index 00619bfad828..93fc01c950e4 100644 --- a/sys/external/bsd/drm2/include/linux/kref.h +++ b/sys/external/bsd/drm2/include/linux/kref.h @@ -58,10 +58,6 @@ kref_get(struct kref *kref) atomic_inc_uint_nv(&kref->kr_count); KASSERTMSG((count > 1), "getting released kref"); - -#ifndef __HAVE_ATOMIC_AS_MEMBAR - membar_enter(); -#endif } static inline bool @@ -76,10 +72,6 @@ kref_get_unless_zero(struct kref *kref) } while (atomic_cas_uint(&kref->kr_count, count, (count + 1)) != count); -#ifndef __HAVE_ATOMIC_AS_MEMBAR - membar_enter(); -#endif - return true; } @@ -89,7 +81,7 @@ kref_sub(struct kref *kref, unsigned int count, void (*release)(struct kref *)) unsigned int old, new; #ifndef __HAVE_ATOMIC_AS_MEMBAR - membar_exit(); + membar_release(); #endif do { @@ -100,6 +92,9 @@ kref_sub(struct kref *kref, unsigned int count, void (*release)(struct kref *)) } while (atomic_cas_uint(&kref->kr_count, old, new) != old); if (new == 0) { +#ifndef __HAVE_ATOMIC_AS_MEMBAR + membar_acquire(); +#endif (*release)(kref); return 1; } @@ -114,7 +109,7 @@ kref_put_lock(struct kref *kref, void (*release)(struct kref *), unsigned int old, new; #ifndef __HAVE_ATOMIC_AS_MEMBAR - membar_exit(); + membar_release(); #endif do { @@ -123,6 +118,9 @@ kref_put_lock(struct kref *kref, void (*release)(struct kref *), if (old == 1) { spin_lock(interlock); if (atomic_add_int_nv(&kref->kr_count, -1) == 0) { +#ifndef __HAVE_ATOMIC_AS_MEMBAR + membar_acquire(); +#endif (*release)(kref); return 1; } @@ -149,7 +147,7 @@ kref_put_mutex(struct kref *kref, void (*release)(struct kref *), unsigned int old, new; #ifndef __HAVE_ATOMIC_AS_MEMBAR - membar_exit(); + membar_release(); #endif do { @@ -158,6 +156,9 @@ kref_put_mutex(struct kref *kref, void (*release)(struct kref *), if (old == 1) { mutex_lock(interlock); if (atomic_add_int_nv(&kref->kr_count, -1) == 0) { +#ifndef __HAVE_ATOMIC_AS_MEMBAR + membar_acquire(); +#endif (*release)(kref); return 1; }