[patch V3 05/28] x86/perf/intel_uncore: Cleanup hardware on exit

From: Thomas Gleixner
Date: Mon Feb 22 2016 - 17:27:53 EST


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@xxxxxxxxxxxxx>
---
V2: Removed the code which affects IVB and newer as Liang pointed out that
it's incorrect
---
arch/x86/kernel/cpu/perf_event_intel_uncore.c | 6 +++++-
arch/x86/kernel/cpu/perf_event_intel_uncore.h | 9 +++++++++
arch/x86/kernel/cpu/perf_event_intel_uncore_nhmex.c | 6 ++++++
arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c | 13 +++++++++++++
4 files changed, 33 insertions(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
@@ -937,6 +937,7 @@ static int uncore_pci_probe(struct pci_d
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
}

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);
+ }
}
}
}
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.h
+++ b/arch/x86/kernel/cpu/perf_event_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(struc
}
}

+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);
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore_nhmex.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore_nhmex.c
@@ -201,6 +201,11 @@ static void nhmex_uncore_msr_init_box(st
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_even

#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, \
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore_snb.c
@@ -95,6 +95,12 @@ static void snb_uncore_msr_init_box(stru
}
}

+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

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(stru
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,