perf/x86/intel/uncore: Clean up hardware on exit

When tearing down the boxes nothing undoes the hardware state which was setup
by box->init_box(). Add a box->exit_box() callback and implement it for the
uncores which have an init_box() callback.

This misses the cleanup in the error exit pathes, but I cannot be bothered to
implement it before cleaning up the rest of the driver, which makes that task
way simpler.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Harish Chegondi <harish.chegondi@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20160222221011.023930023@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/events/intel/uncore.c

@@ -937,6 +937,7 @@ static int uncore_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id
 		raw_spin_lock(&uncore_box_lock);
 		list_del(&box->list);
 		raw_spin_unlock(&uncore_box_lock);
+		uncore_box_exit(box);
 		kfree(box);
 	}
 	return ret;
@@ -982,6 +983,7 @@ static void uncore_pci_remove(struct pci_dev *pdev)
 	}
 
 	WARN_ON_ONCE(atomic_read(&box->refcnt) != 1);
+	uncore_box_exit(box);
 	kfree(box);
 
 	if (last_box)
@@ -1091,8 +1093,10 @@ static void uncore_cpu_dying(int cpu)
 			pmu = &type->pmus[j];
 			box = *per_cpu_ptr(pmu->box, cpu);
 			*per_cpu_ptr(pmu->box, cpu) = NULL;
-			if (box && atomic_dec_and_test(&box->refcnt))
+			if (box && atomic_dec_and_test(&box->refcnt)) {
 				list_add(&box->list, &boxes_to_free);
+				uncore_box_exit(box);
+			}
 		}
 	}
 }

arch/x86/events/intel/uncore.h

@@ -61,6 +61,7 @@ struct intel_uncore_type {
 
 struct intel_uncore_ops {
 	void (*init_box)(struct intel_uncore_box *);
+	void (*exit_box)(struct intel_uncore_box *);
 	void (*disable_box)(struct intel_uncore_box *);
 	void (*enable_box)(struct intel_uncore_box *);
 	void (*disable_event)(struct intel_uncore_box *, struct perf_event *);
@@ -306,6 +307,14 @@ 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 (box->pmu->type->ops->exit_box)
+			box->pmu->type->ops->exit_box(box);
+	}
+}
+
 static inline bool uncore_box_is_fake(struct intel_uncore_box *box)
 {
 	return (box->phys_id < 0);

arch/x86/events/intel/uncore_nhmex.c

@@ -201,6 +201,11 @@ static void nhmex_uncore_msr_init_box(struct intel_uncore_box *box)
 	wrmsrl(NHMEX_U_MSR_PMON_GLOBAL_CTL, NHMEX_U_PMON_GLOBAL_EN_ALL);
 }
 
+static void nhmex_uncore_msr_exit_box(struct intel_uncore_box *box)
+{
+	wrmsrl(NHMEX_U_MSR_PMON_GLOBAL_CTL, 0);
+}
+
 static void nhmex_uncore_msr_disable_box(struct intel_uncore_box *box)
 {
 	unsigned msr = uncore_msr_box_ctl(box);
@@ -250,6 +255,7 @@ static void nhmex_uncore_msr_enable_event(struct intel_uncore_box *box, struct p
 
 #define NHMEX_UNCORE_OPS_COMMON_INIT()				\
 	.init_box	= nhmex_uncore_msr_init_box,		\
+	.exit_box	= nhmex_uncore_msr_exit_box,		\
 	.disable_box	= nhmex_uncore_msr_disable_box,		\
 	.enable_box	= nhmex_uncore_msr_enable_box,		\
 	.disable_event	= nhmex_uncore_msr_disable_event,	\

arch/x86/events/intel/uncore_snb.c

@@ -95,6 +95,12 @@ static void snb_uncore_msr_init_box(struct intel_uncore_box *box)
 	}
 }
 
+static void snb_uncore_msr_exit_box(struct intel_uncore_box *box)
+{
+	if (box->pmu->pmu_idx == 0)
+		wrmsrl(SNB_UNC_PERF_GLOBAL_CTL, 0);
+}
+
 static struct uncore_event_desc snb_uncore_events[] = {
 	INTEL_UNCORE_EVENT_DESC(clockticks, "event=0xff,umask=0x00"),
 	{ /* end: all zeroes */ },
@@ -116,6 +122,7 @@ static struct attribute_group snb_uncore_format_group = {
 
 static struct intel_uncore_ops snb_uncore_msr_ops = {
 	.init_box	= snb_uncore_msr_init_box,
+	.exit_box	= snb_uncore_msr_exit_box,
 	.disable_event	= snb_uncore_msr_disable_event,
 	.enable_event	= snb_uncore_msr_enable_event,
 	.read_counter	= uncore_msr_read_counter,
@@ -231,6 +238,11 @@ static void snb_uncore_imc_init_box(struct intel_uncore_box *box)
 	box->hrtimer_duration = UNCORE_SNB_IMC_HRTIMER_INTERVAL;
 }
 
+static void snb_uncore_imc_exit_box(struct intel_uncore_box *box)
+{
+	iounmap(box->io_addr);
+}
+
 static void snb_uncore_imc_enable_box(struct intel_uncore_box *box)
 {}
 
@@ -458,6 +470,7 @@ static struct pmu snb_uncore_imc_pmu = {
 
 static struct intel_uncore_ops snb_uncore_imc_ops = {
 	.init_box	= snb_uncore_imc_init_box,
+	.exit_box	= snb_uncore_imc_exit_box,
 	.enable_box	= snb_uncore_imc_enable_box,
 	.disable_box	= snb_uncore_imc_disable_box,
 	.disable_event	= snb_uncore_imc_disable_event,