|
 |
ed5979 |
From 67bbeb056f75adc6c964468d876531ab68366fe0 Mon Sep 17 00:00:00 2001
|
|
|
ed5979 |
From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
|
|
|
ed5979 |
Date: Thu, 9 Mar 2023 08:24:36 -0500
|
|
|
ed5979 |
Subject: [PATCH 07/12] edu: add smp_mb__after_rmw()
|
|
|
ed5979 |
|
|
|
ed5979 |
RH-Author: Emanuele Giuseppe Esposito <eesposit@redhat.com>
|
|
|
ed5979 |
RH-MergeRequest: 158: qatomic: add smp_mb__before/after_rmw()
|
|
|
ed5979 |
RH-Bugzilla: 2175660
|
|
|
ed5979 |
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
|
ed5979 |
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
|
|
|
ed5979 |
RH-Acked-by: David Hildenbrand <david@redhat.com>
|
|
|
ed5979 |
RH-Acked-by: Eric Auger <eric.auger@redhat.com>
|
|
|
ed5979 |
RH-Commit: [4/9] 2ad6fd6cb33fde39d2d017d94c0dde2152ad70c4 (eesposit/qemu-kvm)
|
|
|
ed5979 |
|
|
|
ed5979 |
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2175660
|
|
|
ed5979 |
|
|
|
ed5979 |
commit 2482aeea4195ad84cf3d4e5b15b28ec5b420ed5a
|
|
|
ed5979 |
Author: Paolo Bonzini <pbonzini@redhat.com>
|
|
|
ed5979 |
Date: Thu Mar 2 11:16:13 2023 +0100
|
|
|
ed5979 |
|
|
|
ed5979 |
edu: add smp_mb__after_rmw()
|
|
|
ed5979 |
|
|
|
ed5979 |
Ensure ordering between clearing the COMPUTING flag and checking
|
|
|
ed5979 |
IRQFACT, and between setting the IRQFACT flag and checking
|
|
|
ed5979 |
COMPUTING. This ensures that no wakeups are lost.
|
|
|
ed5979 |
|
|
|
ed5979 |
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
|
|
|
ed5979 |
Reviewed-by: David Hildenbrand <david@redhat.com>
|
|
|
ed5979 |
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
|
ed5979 |
|
|
|
ed5979 |
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
|
|
|
ed5979 |
---
|
|
|
ed5979 |
hw/misc/edu.c | 5 +++++
|
|
|
ed5979 |
1 file changed, 5 insertions(+)
|
|
|
ed5979 |
|
|
|
ed5979 |
diff --git a/hw/misc/edu.c b/hw/misc/edu.c
|
|
|
ed5979 |
index e935c418d4..a1f8bc77e7 100644
|
|
|
ed5979 |
--- a/hw/misc/edu.c
|
|
|
ed5979 |
+++ b/hw/misc/edu.c
|
|
|
ed5979 |
@@ -267,6 +267,8 @@ static void edu_mmio_write(void *opaque, hwaddr addr, uint64_t val,
|
|
|
ed5979 |
case 0x20:
|
|
|
ed5979 |
if (val & EDU_STATUS_IRQFACT) {
|
|
|
ed5979 |
qatomic_or(&edu->status, EDU_STATUS_IRQFACT);
|
|
|
ed5979 |
+ /* Order check of the COMPUTING flag after setting IRQFACT. */
|
|
|
ed5979 |
+ smp_mb__after_rmw();
|
|
|
ed5979 |
} else {
|
|
|
ed5979 |
qatomic_and(&edu->status, ~EDU_STATUS_IRQFACT);
|
|
|
ed5979 |
}
|
|
|
ed5979 |
@@ -349,6 +351,9 @@ static void *edu_fact_thread(void *opaque)
|
|
|
ed5979 |
qemu_mutex_unlock(&edu->thr_mutex);
|
|
|
ed5979 |
qatomic_and(&edu->status, ~EDU_STATUS_COMPUTING);
|
|
|
ed5979 |
|
|
|
ed5979 |
+ /* Clear COMPUTING flag before checking IRQFACT. */
|
|
|
ed5979 |
+ smp_mb__after_rmw();
|
|
|
ed5979 |
+
|
|
|
ed5979 |
if (qatomic_read(&edu->status) & EDU_STATUS_IRQFACT) {
|
|
|
ed5979 |
qemu_mutex_lock_iothread();
|
|
|
ed5979 |
edu_raise_irq(edu, FACT_IRQ);
|
|
|
ed5979 |
--
|
|
|
ed5979 |
2.39.1
|
|
|
ed5979 |
|