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| author | Konstantin Belousov <kib@FreeBSD.org> | 2018-06-08 18:32:26 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2018-06-08 18:32:26 +0000 |
| commit | 8d59ab652b1b27f6b043a764c731134b7a2d0ebd (patch) | |
| tree | 4de2346c17be7a4b0e7c9cace7384e60783bf6cf /sys/arm64 | |
| parent | 6272d7e647e0493a40092ea2bd5c19526ffa3e1f (diff) | |
| download | src-8d59ab652b1b27f6b043a764c731134b7a2d0ebd.tar.gz src-8d59ab652b1b27f6b043a764c731134b7a2d0ebd.zip | |
Restore release semantic for the old thread unlock on arm64.
With the introduction of pmap_switch(), the DSB instruction on the
address map switch is not necessary executed, which is fixed by
changing the unlock store to release. Also remove comment which
documented pre-pmap_switch() code.
Reviewed by: andrew
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Notes
Notes:
svn path=/head/; revision=334851
Diffstat (limited to 'sys/arm64')
| -rw-r--r-- | sys/arm64/arm64/swtch.S | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/sys/arm64/arm64/swtch.S b/sys/arm64/arm64/swtch.S index c9843303b1d3..4c2c3aca5833 100644 --- a/sys/arm64/arm64/swtch.S +++ b/sys/arm64/arm64/swtch.S @@ -165,10 +165,9 @@ ENTRY(cpu_switch) mov x0, x19 /* - * Release the old thread. This doesn't need to be a store-release - * as the above dsb instruction will provide release semantics. + * Release the old thread. */ - str x2, [x0, #TD_LOCK] + stlr x2, [x0, #TD_LOCK] #if defined(SCHED_ULE) && defined(SMP) /* Spin if TD_LOCK points to a blocked_lock */ ldr x2, =_C_LABEL(blocked_lock) |