Patch "powerpc/perf: Convert fsl_emb notifier to state machine callbacks" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    powerpc/perf: Convert fsl_emb notifier to state machine callbacks

to the 5.10-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-perf-convert-fsl_emb-notifier-to-state-machi.patch
and it can be found in the queue-5.10 subdirectory.

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



commit 2d6c7076001e7bc8bfdd8c08e49a04e017979ee1
Author: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Date:   Fri Aug 18 10:59:44 2023 +0200

    powerpc/perf: Convert fsl_emb notifier to state machine callbacks
    
    [ Upstream commit 34daf445f82bd3a4df852bb5f1dffd792ac830a0 ]
    
      CC      arch/powerpc/perf/core-fsl-emb.o
    arch/powerpc/perf/core-fsl-emb.c:675:6: error: no previous prototype for 'hw_perf_event_setup' [-Werror=missing-prototypes]
      675 | void hw_perf_event_setup(int cpu)
          |      ^~~~~~~~~~~~~~~~~~~
    
    Looks like fsl_emb was completely missed by commit 3f6da3905398 ("perf:
    Rework and fix the arch CPU-hotplug hooks")
    
    So, apply same changes as commit 3f6da3905398 ("perf: Rework and fix
    the arch CPU-hotplug hooks") then commit 57ecde42cc74 ("powerpc/perf:
    Convert book3s notifier to state machine callbacks")
    
    While at it, also fix following error:
    
    arch/powerpc/perf/core-fsl-emb.c: In function 'perf_event_interrupt':
    arch/powerpc/perf/core-fsl-emb.c:648:13: error: variable 'found' set but not used [-Werror=unused-but-set-variable]
      648 |         int found = 0;
          |             ^~~~~
    
    Fixes: 3f6da3905398 ("perf: Rework and fix the arch CPU-hotplug hooks")
    Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
    Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
    Link: https://msgid.link/603e1facb32608f88f40b7d7b9094adc50e7b2dc.1692349125.git.christophe.leroy@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/powerpc/perf/core-fsl-emb.c b/arch/powerpc/perf/core-fsl-emb.c
index ee721f420a7ba..1a53ab08447cb 100644
--- a/arch/powerpc/perf/core-fsl-emb.c
+++ b/arch/powerpc/perf/core-fsl-emb.c
@@ -645,7 +645,6 @@ static void perf_event_interrupt(struct pt_regs *regs)
 	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event;
 	unsigned long val;
-	int found = 0;
 
 	for (i = 0; i < ppmu->n_counter; ++i) {
 		event = cpuhw->event[i];
@@ -654,7 +653,6 @@ static void perf_event_interrupt(struct pt_regs *regs)
 		if ((int)val < 0) {
 			if (event) {
 				/* event has overflowed */
-				found = 1;
 				record_and_restart(event, val, regs);
 			} else {
 				/*
@@ -672,11 +670,13 @@ static void perf_event_interrupt(struct pt_regs *regs)
 	isync();
 }
 
-void hw_perf_event_setup(int cpu)
+static int fsl_emb_pmu_prepare_cpu(unsigned int cpu)
 {
 	struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu);
 
 	memset(cpuhw, 0, sizeof(*cpuhw));
+
+	return 0;
 }
 
 int register_fsl_emb_pmu(struct fsl_emb_pmu *pmu)
@@ -689,6 +689,8 @@ int register_fsl_emb_pmu(struct fsl_emb_pmu *pmu)
 		pmu->name);
 
 	perf_pmu_register(&fsl_emb_pmu, "cpu", PERF_TYPE_RAW);
+	cpuhp_setup_state(CPUHP_PERF_POWER, "perf/powerpc:prepare",
+			  fsl_emb_pmu_prepare_cpu, NULL);
 
 	return 0;
 }