[PATCH 2/2] powerpc/papr_scm: Fix build failure when CONFIG_PERF_EVENTS is not set

[Kajol Jain]

The following build failure occures when CONFIG_PERF_EVENTS is not set
as generic pmu functions are not visible in that scenario.

arch/powerpc/platforms/pseries/papr_scm.c:372:35: error: ‘struct perf_event’ has no member named ‘attr’
         p->nvdimm_events_map[event->attr.config],
                                   ^~
In file included from ./include/linux/list.h:5,
                 from ./include/linux/kobject.h:19,
                 from ./include/linux/of.h:17,
                 from arch/powerpc/platforms/pseries/papr_scm.c:5:
arch/powerpc/platforms/pseries/papr_scm.c: In function ‘papr_scm_pmu_event_init’:
arch/powerpc/platforms/pseries/papr_scm.c:389:49: error: ‘struct perf_event’ has no member named ‘pmu’
  struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
                                                 ^~
./include/linux/container_of.h:18:26: note: in definition of macro ‘container_of’
  void *__mptr = (void *)(ptr);     \
                          ^~~
arch/powerpc/platforms/pseries/papr_scm.c:389:30: note: in expansion of macro ‘to_nvdimm_pmu’
  struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
                              ^~~~~~~~~~~~~
In file included from ./include/linux/bits.h:22,
                 from ./include/linux/bitops.h:6,
                 from ./include/linux/of.h:15,
                 from arch/powerpc/platforms/pseries/papr_scm.c:5:

Fix the build issue by adding check for CONFIG_PERF_EVENTS config option
and disabling the papr_scm perf interface support incase this config
is not set

Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") (Commit id
based on linux-next tree)
Signed-off-by: Kajol Jain <kjain@xxxxxxxxxxxxx>
---
 arch/powerpc/platforms/pseries/papr_scm.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

---
- This fix patch changes are added and tested on top of linux-next tree
  on the 'next-20220315' branch.
---
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
index 4f65bc0fb861..ffe85aeb4127 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -19,7 +19,10 @@
 #include <asm/papr_pdsm.h>
 #include <asm/mce.h>
 #include <asm/unaligned.h>
+
+#ifdef CONFIG_PERF_EVENTS
 #include <linux/perf_event.h>
+#endif
 
 #define BIND_ANY_ADDR (~0ul)
 
@@ -69,7 +72,9 @@
 #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
 #define PAPR_SCM_PERF_STATS_VERSION 0x1
 
+#ifdef CONFIG_PERF_EVENTS
 #define to_nvdimm_pmu(_pmu)	container_of(_pmu, struct nvdimm_pmu, pmu)
+#endif
 
 /* Struct holding a single performance metric */
 struct papr_scm_perf_stat {
@@ -127,8 +132,10 @@ struct papr_scm_priv {
 	/* The bits which needs to be overridden */
 	u64 health_bitmap_inject_mask;
 
+#ifdef CONFIG_PERF_EVENTS
 	 /* array to have event_code and stat_id mappings */
 	char **nvdimm_events_map;
+#endif
 };
 
 static int papr_scm_pmem_flush(struct nd_region *nd_region,
@@ -349,6 +356,7 @@ static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
 	return 0;
 }
 
+#ifdef CONFIG_PERF_EVENTS
 static int papr_scm_pmu_get_value(struct perf_event *event, struct device *dev, u64 *count)
 {
 	struct papr_scm_perf_stat *stat;
@@ -560,6 +568,7 @@ static void papr_scm_pmu_register(struct papr_scm_priv *p)
 pmu_err_print:
 	dev_info(&p->pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
 }
+#endif
 
 /*
  * Issue hcall to retrieve dimm health info and populate papr_scm_priv with the
@@ -1537,7 +1546,10 @@ static int papr_scm_probe(struct platform_device *pdev)
 		goto err2;
 
 	platform_set_drvdata(pdev, p);
+
+#ifdef CONFIG_PERF_EVENTS
 	papr_scm_pmu_register(p);
+#endif
 
 	return 0;
 
@@ -1557,11 +1569,14 @@ static int papr_scm_remove(struct platform_device *pdev)
 	nvdimm_bus_unregister(p->bus);
 	drc_pmem_unbind(p);
 
+#ifdef CONFIG_PERF_EVENTS
 	if (pdev->archdata.priv)
 		unregister_nvdimm_pmu(pdev->archdata.priv);
 
 	pdev->archdata.priv = NULL;
 	kfree(p->nvdimm_events_map);
+#endif
+
 	kfree(p->bus_desc.provider_name);
 	kfree(p);
 
-- 
2.31.1