Patch "powerpc/pseries/mobility: use struct for shared state" has been added to the 5.11-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    powerpc/pseries/mobility: use struct for shared state

to the 5.11-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     powerpc-pseries-mobility-use-struct-for-shared-state.patch
and it can be found in the queue-5.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit a33b58f9a1a3b25fd0e036664ddcb411b59d7c90
Author: Nathan Lynch <nathanl@xxxxxxxxxxxxx>
Date:   Mon Mar 15 03:00:44 2021 -0500

    powerpc/pseries/mobility: use struct for shared state
    
    [ 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@xxxxxxxxxxxxx>
    Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20210315080045.460331-2-nathanl@xxxxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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;
 		/*