[PATCH 5.11 124/152] powerpc/pseries/mobility: use struct for shared state

Greg Kroah-Hartman
2021-04-05T09:21:53Z

From: Nathan Lynch <nathanl@linux.ibm.com>

[ Upstream commit e834df6cfc71d8e5ce2c27a0184145ea125c3f0f ]

The atomic_t counter is the only shared state for the join/suspend
sequence so far, but that will change. Contain it in a
struct (pseries_suspend_info), and document its intended use. No
functional change.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210315080045.460331-2-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/platforms/pseries/mobility.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index ea4d6a660e0d..a6739ce9feac 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -452,9 +452,21 @@ static int do_suspend(void)
return ret;
}

+/**
+ * struct pseries_suspend_info - State shared between CPUs for join/suspend.
+ * @counter: Threads are to increment this upon resuming from suspend
+ * or if an error is received from H_JOIN. The thread which performs
+ * the first increment (i.e. sets it to 1) is responsible for
+ * waking the other threads.
+ */
+struct pseries_suspend_info {
+ atomic_t counter;
+};
+
static int do_join(void *arg)
{
- atomic_t *counter = arg;
+ struct pseries_suspend_info *info = arg;
+ atomic_t *counter = &info->counter;
long hvrc;
int ret;

@@ -535,11 +547,15 @@ static int pseries_suspend(u64 handle)
int ret;

while (true) {
- atomic_t counter = ATOMIC_INIT(0);
+ struct pseries_suspend_info info;
unsigned long vasi_state;
int vasi_err;

- ret = stop_machine(do_join, &counter, cpu_online_mask);
+ info = (struct pseries_suspend_info) {
+ .counter = ATOMIC_INIT(0),
+ };
+
+ ret = stop_machine(do_join, &info, cpu_online_mask);
if (ret == 0)
break;
/*
--
2.30.2