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| author |   Rohan McLure <rmclure@linux.ibm.com> | 2023-05-10 13:31:15 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2023-06-21 15:13:57 +1000 |
| commit | 331e2cad6d168ac5ccb25ae34bdc305b8b731bc0 (patch) | |
| tree | b0599c92a1ac5d9958abed5d407de616a9c7f53d | |
| parent | powerpc: Mark writes registering ipi to host cpu through kvm and polling (diff) | |
| download | wireguard-linux-331e2cad6d168ac5ccb25ae34bdc305b8b731bc0.tar.xz wireguard-linux-331e2cad6d168ac5ccb25ae34bdc305b8b731bc0.zip | |
powerpc: powernv: Annotate data races in opal events
The kopald thread handles opal events as they appear, but by polling a
static bit-vector in last_outstanding_events. Annotate these data races
accordingly. We are not at risk of missing events, but use of READ_ONCE,
WRITE_ONCE will assist readers in seeing that kopald only consumes the
events it is aware of when it is scheduled. Also removes extraneous
KCSAN warnings.
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230510033117.1395895-10-rmclure@linux.ibm.com
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal-irqchip.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-irqchip.c b/arch/powerpc/platforms/powernv/opal-irqchip.c index d55652b5f6fa..f9a7001dacb7 100644 --- a/arch/powerpc/platforms/powernv/opal-irqchip.c +++ b/arch/powerpc/platforms/powernv/opal-irqchip.c @@ -59,7 +59,7 @@ again: cond_resched(); } - last_outstanding_events = 0; + WRITE_ONCE(last_outstanding_events, 0); if (opal_poll_events(&events) != OPAL_SUCCESS) return; e = be64_to_cpu(events) & opal_event_irqchip.mask; @@ -69,7 +69,7 @@ again: bool opal_have_pending_events(void) { - if (last_outstanding_events & opal_event_irqchip.mask) + if (READ_ONCE(last_outstanding_events) & opal_event_irqchip.mask) return true; return false; } @@ -124,7 +124,7 @@ static irqreturn_t opal_interrupt(int irq, void *data) __be64 events; opal_handle_interrupt(virq_to_hw(irq), &events); - last_outstanding_events = be64_to_cpu(events); + WRITE_ONCE(last_outstanding_events, be64_to_cpu(events)); if (opal_have_pending_events()) opal_wake_poller(); |