[PATCH V3 2/8] perf/x86/intel/uncore: Fix refcnt and other cleanups

[Zide Chen <zide.chen@intel.com>]

Fix typo UNCORE_BOX_FLAG_INITIATED to UNCORE_BOX_FLAG_INITIALIZED.

Rename the 'id' parameter in uncore_box_{ref,unref}() to 'die' to
reflect its actual meaning and be consistent with other functions.

box->refcnt is incremented in the PCI PMU register path but has never
been checked or decremented. Although for PCI PMUs box->refcnt
effectively tracks only a single user, add atomic_dec_return() in the
PCI PMU unregister path to make the reference counting complete and
consistent.

Signed-off-by: Zide Chen <zide.chen@intel.com>
---
v3:
- Instead of removing atomic_inc(&box->refcnt) in PMU register, add
  the corresponding atomic_dec_return(&box->refcnt) in PMU unregister.
  (Dapeng)
v2:
- Don't rename pmu->activeboxes and keep its semantics because in
  uncore_pci_remove() path, uncore_pci_pmu_unregister() won't be
  called for non-active boxes.
- Since pmu->activeboxes keeps its name, don't need to rename
  box->refcnt to box->cpu_refcnt.
---
 arch/x86/events/intel/uncore.c | 16 +++++++++-------
 arch/x86/events/intel/uncore.h |  6 +++---
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index b69b6a21d46b..21c8ed1628cb 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -1255,8 +1255,10 @@ static void uncore_pci_pmu_unregister(struct intel_uncore_pmu *pmu, int die)
 	pmu->boxes[die] = NULL;
 	if (atomic_dec_return(&pmu->activeboxes) == 0)
 		uncore_pmu_unregister(pmu);
-	uncore_box_exit(box);
-	kfree(box);
+	if (atomic_dec_return(&box->refcnt) == 0) {
+		uncore_box_exit(box);
+		kfree(box);
+	}
 }
 
 static void uncore_pci_remove(struct pci_dev *pdev)
@@ -1518,7 +1520,7 @@ static void uncore_change_context(struct intel_uncore_type **uncores,
 		uncore_change_type_ctx(*uncores, old_cpu, new_cpu);
 }
 
-static void uncore_box_unref(struct intel_uncore_type **types, int id)
+static void uncore_box_unref(struct intel_uncore_type **types, int die)
 {
 	struct intel_uncore_type *type;
 	struct intel_uncore_pmu *pmu;
@@ -1529,7 +1531,7 @@ static void uncore_box_unref(struct intel_uncore_type **types, int id)
 		type = *types;
 		pmu = type->pmus;
 		for (i = 0; i < type->num_boxes; i++, pmu++) {
-			box = pmu->boxes[id];
+			box = pmu->boxes[die];
 			if (box && box->cpu >= 0 && atomic_dec_return(&box->refcnt) == 0)
 				uncore_box_exit(box);
 		}
@@ -1604,14 +1606,14 @@ static int allocate_boxes(struct intel_uncore_type **types,
 }
 
 static int uncore_box_ref(struct intel_uncore_type **types,
-			  int id, unsigned int cpu)
+			  int die, unsigned int cpu)
 {
 	struct intel_uncore_type *type;
 	struct intel_uncore_pmu *pmu;
 	struct intel_uncore_box *box;
 	int i, ret;
 
-	ret = allocate_boxes(types, id, cpu);
+	ret = allocate_boxes(types, die, cpu);
 	if (ret)
 		return ret;
 
@@ -1619,7 +1621,7 @@ static int uncore_box_ref(struct intel_uncore_type **types,
 		type = *types;
 		pmu = type->pmus;
 		for (i = 0; i < type->num_boxes; i++, pmu++) {
-			box = pmu->boxes[id];
+			box = pmu->boxes[die];
 			if (box && box->cpu >= 0 && atomic_inc_return(&box->refcnt) == 1)
 				uncore_box_init(box);
 		}
diff --git a/arch/x86/events/intel/uncore.h b/arch/x86/events/intel/uncore.h
index c2e5ccb1d72c..bad5d8dec8e0 100644
--- a/arch/x86/events/intel/uncore.h
+++ b/arch/x86/events/intel/uncore.h
@@ -185,7 +185,7 @@ struct intel_uncore_box {
 #define CFL_UNC_CBO_7_PERFEVTSEL0		0xf70
 #define CFL_UNC_CBO_7_PER_CTR0			0xf76
 
-#define UNCORE_BOX_FLAG_INITIATED		0
+#define UNCORE_BOX_FLAG_INITIALIZED		0
 /* event config registers are 8-byte apart */
 #define UNCORE_BOX_FLAG_CTL_OFFS8		1
 /* CFL 8th CBOX has different MSR space */
@@ -559,7 +559,7 @@ static inline u64 uncore_read_counter(struct intel_uncore_box *box,
 
 static inline void uncore_box_init(struct intel_uncore_box *box)
 {
-	if (!test_and_set_bit(UNCORE_BOX_FLAG_INITIATED, &box->flags)) {
+	if (!test_and_set_bit(UNCORE_BOX_FLAG_INITIALIZED, &box->flags)) {
 		if (box->pmu->type->ops->init_box)
 			box->pmu->type->ops->init_box(box);
 	}
@@ -567,7 +567,7 @@ static inline void uncore_box_init(struct intel_uncore_box *box)
 
 static inline void uncore_box_exit(struct intel_uncore_box *box)
 {
-	if (test_and_clear_bit(UNCORE_BOX_FLAG_INITIATED, &box->flags)) {
+	if (test_and_clear_bit(UNCORE_BOX_FLAG_INITIALIZED, &box->flags)) {
 		if (box->pmu->type->ops->exit_box)
 			box->pmu->type->ops->exit_box(box);
 	}
-- 
2.54.0