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Commit c05199e5 authored by Kan Liang's avatar Kan Liang Committed by Ingo Molnar
Browse files

perf/x86/intel/uncore: Move uncore_box_init() out of driver initialization 



There were some issues about the uncore driver tried to access
non-existing boxes, which caused boot crashes. These issues have
been all fixed. But we should avoid boot failures if that ever
happens again.

This patch intends to prevent this kind of potential issues.
It moves uncore_box_init out of driver initialization. The box
will be initialized when it's first enabled.

Signed-off-by: default avatarKan Liang <kan.liang@intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1421729665-5912-1-git-send-email-kan.liang@intel.com


Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 4adca1cb

arch/x86/kernel/cpu/perf_event_intel_uncore.c

+2 −7
Original line number Diff line number Diff line
@@ -840,7 +840,6 @@ static int uncore_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id 
	box->phys_id = phys_id;

	box->pci_dev = pdev;

	box->pmu = pmu;

	uncore_box_init(box);

	pci_set_drvdata(pdev, box);



	raw_spin_lock(&uncore_box_lock);
@@ -1004,10 +1003,8 @@ static int uncore_cpu_starting(int cpu) 
			pmu = &type->pmus[j];

			box = *per_cpu_ptr(pmu->box, cpu);

			/* called by uncore_cpu_init? */

			if (box && box->phys_id >= 0) {

				uncore_box_init(box);

			if (box && box->phys_id >= 0)

				continue;

			}



			for_each_online_cpu(k) {

				exist = *per_cpu_ptr(pmu->box, k);
@@ -1023,10 +1020,8 @@ static int uncore_cpu_starting(int cpu) 
				}

			}



			if (box) {

			if (box)

				box->phys_id = phys_id;

				uncore_box_init(box);

			}

		}

	}

	return 0;

arch/x86/kernel/cpu/perf_event_intel_uncore.h

+10 −8
Original line number Diff line number Diff line
@@ -257,6 +257,14 @@ static inline int uncore_num_counters(struct intel_uncore_box *box) 
	return box->pmu->type->num_counters;

}



static inline void uncore_box_init(struct intel_uncore_box *box)

{

	if (!test_and_set_bit(UNCORE_BOX_FLAG_INITIATED, &box->flags)) {

		if (box->pmu->type->ops->init_box)

			box->pmu->type->ops->init_box(box);

	}

}



static inline void uncore_disable_box(struct intel_uncore_box *box)

{

	if (box->pmu->type->ops->disable_box)
@@ -265,6 +273,8 @@ static inline void uncore_disable_box(struct intel_uncore_box *box) 


static inline void uncore_enable_box(struct intel_uncore_box *box)

{

	uncore_box_init(box);



	if (box->pmu->type->ops->enable_box)

		box->pmu->type->ops->enable_box(box);

}
@@ -287,14 +297,6 @@ static inline u64 uncore_read_counter(struct intel_uncore_box *box, 
	return box->pmu->type->ops->read_counter(box, event);

}



static inline void uncore_box_init(struct intel_uncore_box *box)

{

	if (!test_and_set_bit(UNCORE_BOX_FLAG_INITIATED, &box->flags)) {

		if (box->pmu->type->ops->init_box)

			box->pmu->type->ops->init_box(box);

	}

}



static inline bool uncore_box_is_fake(struct intel_uncore_box *box)

{

	return (box->phys_id < 0);