[v7,2/4] perf/smmuv3: Add arm64 smmuv3 pmu driver

Message ID 20190326151753.19384-3-shameerali.kolothum.thodi@huawei.com
State New
Headers show
Series
  • arm64 SMMUv3 PMU driver with IORT support
Related show

Commit Message

Shameerali Kolothum Thodi March 26, 2019, 3:17 p.m.
From: Neil Leeder <nleeder@codeaurora.org>


Adds a new driver to support the SMMUv3 PMU and add it into the
perf events framework.

Each SMMU node may have multiple PMUs associated with it, each of
which may support different events.

SMMUv3 PMCG devices are named as smmuv3_pmcg_<phys_addr_page> where
<phys_addr_page> is the physical page address of the SMMU PMCG
wrapped to 4K boundary. For example, the PMCG at 0xff88840000 is
named smmuv3_pmcg_ff88840

Filtering by stream id is done by specifying filtering parameters
with the event. options are:
   filter_enable    - 0 = no filtering, 1 = filtering enabled
   filter_span      - 0 = exact match, 1 = pattern match
   filter_stream_id - pattern to filter against

Example: perf stat -e smmuv3_pmcg_ff88840/transaction,filter_enable=1,
                       filter_span=1,filter_stream_id=0x42/ -a netperf

Applies filter pattern 0x42 to transaction events, which means events
matching stream ids 0x42 & 0x43 are counted as only upper StreamID
bits are required to match the given filter. Further filtering
information is available in the SMMU documentation.

SMMU events are not attributable to a CPU, so task mode and sampling
are not supported.

Signed-off-by: Neil Leeder <nleeder@codeaurora.org>

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

Reviewed-by: Robin Murphy <robin.murphy@arm.com>

---
 drivers/perf/Kconfig          |   9 +
 drivers/perf/Makefile         |   1 +
 drivers/perf/arm_smmuv3_pmu.c | 776 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 786 insertions(+)
 create mode 100644 drivers/perf/arm_smmuv3_pmu.c

-- 
2.7.4

Comments

Robin Murphy March 26, 2019, 4:57 p.m. | #1
Hi Shameer,

On 26/03/2019 15:17, Shameer Kolothum wrote:
[...]
> +static int smmu_pmu_apply_event_filter(struct smmu_pmu *smmu_pmu,

> +				       struct perf_event *event, int idx)

> +{

> +	u32 span, sid;

> +	unsigned int num_ctrs = smmu_pmu->num_counters;

> +	bool filter_en = !!get_filter_enable(event);

> +

> +	span = filter_en ? get_filter_span(event) :

> +			   SMMU_PMCG_DEFAULT_FILTER_SPAN;

> +	sid = filter_en ? get_filter_stream_id(event) :

> +			   SMMU_PMCG_DEFAULT_FILTER_SID;

> +

> +	/* Support individual filter settings */

> +	if (!smmu_pmu->global_filter) {

> +		smmu_pmu_set_event_filter(event, idx, span, sid);

> +		return 0;

> +	}

> +

> +	/* Requested settings same as current global settings*/

> +	if (span == smmu_pmu->global_filter_span &&

> +	    sid == smmu_pmu->global_filter_sid)

> +		return 0;

> +

> +	if (!bitmap_empty(smmu_pmu->used_counters, num_ctrs))

> +		return -EAGAIN;

> +

> +	if (idx == 0) {

> +		smmu_pmu_set_event_filter(event, idx, span, sid);

> +		smmu_pmu->global_filter_span = span;

> +		smmu_pmu->global_filter_sid = sid;

> +		return 0;

> +	}


When I suggested dropping the check of idx, I did mean removing it 
entirely, not just moving it further down ;)

Nothing to worry about though, I'll just leave this here for Will to 
consider applying on top or squashing.

Thanks,
Robin.

----->8-----
From: Robin Murphy <robin.murphy@arm.com>

Subject: [PATCH] perf/smmuv3: Relax global filter constraint a little

Although the current behaviour of smmu_pmu_get_event_idx() effectively
ensures that the first-allocated counter will be counter 0, there's no
need to strictly enforce that in smmu_pmu_apply_event_filter(). All that
matters is that we only ever touch the global filter settings in
SMMU_PMCG_SMR0 and SMMU_PMCG_EVTYPER0 while no counters are active.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>

---
  drivers/perf/arm_smmuv3_pmu.c | 11 ++++-------
  1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
index 6b3c0ed7ad71..23045ead6de1 100644
--- a/drivers/perf/arm_smmuv3_pmu.c
+++ b/drivers/perf/arm_smmuv3_pmu.c
@@ -286,14 +286,11 @@ static int smmu_pmu_apply_event_filter(struct 
smmu_pmu *smmu_pmu,
  	if (!bitmap_empty(smmu_pmu->used_counters, num_ctrs))
  		return -EAGAIN;

-	if (idx == 0) {
-		smmu_pmu_set_event_filter(event, idx, span, sid);
-		smmu_pmu->global_filter_span = span;
-		smmu_pmu->global_filter_sid = sid;
-		return 0;
-	}
+	smmu_pmu_set_event_filter(event, 0, span, sid);
+	smmu_pmu->global_filter_span = span;
+	smmu_pmu->global_filter_sid = sid;

-	return -EAGAIN;
+	return 0;
  }

  static int smmu_pmu_get_event_idx(struct smmu_pmu *smmu_pmu,
-- 
2.20.1.dirty
Shameerali Kolothum Thodi March 26, 2019, 5:02 p.m. | #2
Hi Robin,

> -----Original Message-----

> From: Robin Murphy [mailto:robin.murphy@arm.com]

> Sent: 26 March 2019 16:58

> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>;

> lorenzo.pieralisi@arm.com

> Cc: andrew.murray@arm.com; jean-philippe.brucker@arm.com;

> will.deacon@arm.com; mark.rutland@arm.com; Guohanjun (Hanjun Guo)

> <guohanjun@huawei.com>; John Garry <john.garry@huawei.com>;

> pabba@codeaurora.org; vkilari@codeaurora.org; rruigrok@codeaurora.org;

> linux-acpi@vger.kernel.org; linux-kernel@vger.kernel.org;

> linux-arm-kernel@lists.infradead.org; Linuxarm <linuxarm@huawei.com>;

> neil.m.leeder@gmail.com

> Subject: Re: [PATCH v7 2/4] perf/smmuv3: Add arm64 smmuv3 pmu driver

> 

> Hi Shameer,

> 

> On 26/03/2019 15:17, Shameer Kolothum wrote:

> [...]

> > +static int smmu_pmu_apply_event_filter(struct smmu_pmu *smmu_pmu,

> > +				       struct perf_event *event, int idx)

> > +{

> > +	u32 span, sid;

> > +	unsigned int num_ctrs = smmu_pmu->num_counters;

> > +	bool filter_en = !!get_filter_enable(event);

> > +

> > +	span = filter_en ? get_filter_span(event) :

> > +			   SMMU_PMCG_DEFAULT_FILTER_SPAN;

> > +	sid = filter_en ? get_filter_stream_id(event) :

> > +			   SMMU_PMCG_DEFAULT_FILTER_SID;

> > +

> > +	/* Support individual filter settings */

> > +	if (!smmu_pmu->global_filter) {

> > +		smmu_pmu_set_event_filter(event, idx, span, sid);

> > +		return 0;

> > +	}

> > +

> > +	/* Requested settings same as current global settings*/

> > +	if (span == smmu_pmu->global_filter_span &&

> > +	    sid == smmu_pmu->global_filter_sid)

> > +		return 0;

> > +

> > +	if (!bitmap_empty(smmu_pmu->used_counters, num_ctrs))

> > +		return -EAGAIN;

> > +

> > +	if (idx == 0) {

> > +		smmu_pmu_set_event_filter(event, idx, span, sid);

> > +		smmu_pmu->global_filter_span = span;

> > +		smmu_pmu->global_filter_sid = sid;

> > +		return 0;

> > +	}

> 

> When I suggested dropping the check of idx, I did mean removing it

> entirely, not just moving it further down ;)


Ah..I must confess that I was slightly confused by that suggestion and 
thought that you are making a case for code being more clear to read :)
 
> Nothing to worry about though, I'll just leave this here for Will to

> consider applying on top or squashing.


Thanks for that.

Cheers,
Shameer

> Thanks,

> Robin.

> 

> ----->8-----

> From: Robin Murphy <robin.murphy@arm.com>

> Subject: [PATCH] perf/smmuv3: Relax global filter constraint a little

> 

> Although the current behaviour of smmu_pmu_get_event_idx() effectively

> ensures that the first-allocated counter will be counter 0, there's no

> need to strictly enforce that in smmu_pmu_apply_event_filter(). All that

> matters is that we only ever touch the global filter settings in

> SMMU_PMCG_SMR0 and SMMU_PMCG_EVTYPER0 while no counters are

> active.

> 

> Signed-off-by: Robin Murphy <robin.murphy@arm.com>

> ---

>   drivers/perf/arm_smmuv3_pmu.c | 11 ++++-------

>   1 file changed, 4 insertions(+), 7 deletions(-)

> 

> diff --git a/drivers/perf/arm_smmuv3_pmu.c

> b/drivers/perf/arm_smmuv3_pmu.c

> index 6b3c0ed7ad71..23045ead6de1 100644

> --- a/drivers/perf/arm_smmuv3_pmu.c

> +++ b/drivers/perf/arm_smmuv3_pmu.c

> @@ -286,14 +286,11 @@ static int smmu_pmu_apply_event_filter(struct

> smmu_pmu *smmu_pmu,

>   	if (!bitmap_empty(smmu_pmu->used_counters, num_ctrs))

>   		return -EAGAIN;

> 

> -	if (idx == 0) {

> -		smmu_pmu_set_event_filter(event, idx, span, sid);

> -		smmu_pmu->global_filter_span = span;

> -		smmu_pmu->global_filter_sid = sid;

> -		return 0;

> -	}

> +	smmu_pmu_set_event_filter(event, 0, span, sid);

> +	smmu_pmu->global_filter_span = span;

> +	smmu_pmu->global_filter_sid = sid;

> 

> -	return -EAGAIN;

> +	return 0;

>   }

> 

>   static int smmu_pmu_get_event_idx(struct smmu_pmu *smmu_pmu,

> --

> 2.20.1.dirty
Will Deacon April 4, 2019, 3:30 p.m. | #3
On Tue, Mar 26, 2019 at 03:17:51PM +0000, Shameer Kolothum wrote:
> From: Neil Leeder <nleeder@codeaurora.org>

> 

> Adds a new driver to support the SMMUv3 PMU and add it into the

> perf events framework.

> 

> Each SMMU node may have multiple PMUs associated with it, each of

> which may support different events.

> 

> SMMUv3 PMCG devices are named as smmuv3_pmcg_<phys_addr_page> where

> <phys_addr_page> is the physical page address of the SMMU PMCG

> wrapped to 4K boundary. For example, the PMCG at 0xff88840000 is

> named smmuv3_pmcg_ff88840

> 

> Filtering by stream id is done by specifying filtering parameters

> with the event. options are:

>    filter_enable    - 0 = no filtering, 1 = filtering enabled

>    filter_span      - 0 = exact match, 1 = pattern match

>    filter_stream_id - pattern to filter against

> 

> Example: perf stat -e smmuv3_pmcg_ff88840/transaction,filter_enable=1,

>                        filter_span=1,filter_stream_id=0x42/ -a netperf

> 

> Applies filter pattern 0x42 to transaction events, which means events

> matching stream ids 0x42 & 0x43 are counted as only upper StreamID

> bits are required to match the given filter. Further filtering

> information is available in the SMMU documentation.

> 

> SMMU events are not attributable to a CPU, so task mode and sampling

> are not supported.

> 

> Signed-off-by: Neil Leeder <nleeder@codeaurora.org>

> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

> Reviewed-by: Robin Murphy <robin.murphy@arm.com>

> ---

>  drivers/perf/Kconfig          |   9 +

>  drivers/perf/Makefile         |   1 +

>  drivers/perf/arm_smmuv3_pmu.c | 776 ++++++++++++++++++++++++++++++++++++++++++

>  3 files changed, 786 insertions(+)

>  create mode 100644 drivers/perf/arm_smmuv3_pmu.c


[...]

> +static int smmu_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)

> +{

> +	struct smmu_pmu *smmu_pmu;

> +	unsigned int target;

> +

> +	smmu_pmu = hlist_entry_safe(node, struct smmu_pmu, node);

> +	if (cpu != smmu_pmu->on_cpu)

> +		return 0;

> +

> +	target = cpumask_any_but(cpu_online_mask, cpu);

> +	if (target >= nr_cpu_ids)

> +		return 0;

> +

> +	perf_pmu_migrate_context(&smmu_pmu->pmu, cpu, target);

> +	smmu_pmu->on_cpu = target;

> +	WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(target)));


I'm going to make this (and the other invocation) use
irq_set_affinity_hint() instead, so that we can build this driver as a
module with the appropriate Kconfig tweak.

Will

Patch

diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index af9bc17..6a472fc 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -52,6 +52,15 @@  config ARM_PMU_ACPI
 	depends on ARM_PMU && ACPI
 	def_bool y
 
+config ARM_SMMU_V3_PMU
+	 bool "ARM SMMUv3 Performance Monitors Extension"
+	 depends on ARM64 && ACPI && ARM_SMMU_V3
+	   help
+	   Provides support for the SMMU version 3 performance monitor unit (PMU)
+	   on ARM-based systems.
+	   Adds the SMMU PMU into the perf events subsystem for
+	   monitoring SMMU performance events.
+
 config ARM_DSU_PMU
 	tristate "ARM DynamIQ Shared Unit (DSU) PMU"
 	depends on ARM64
diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
index 909f27f..3048994 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -4,6 +4,7 @@  obj-$(CONFIG_ARM_CCN) += arm-ccn.o
 obj-$(CONFIG_ARM_DSU_PMU) += arm_dsu_pmu.o
 obj-$(CONFIG_ARM_PMU) += arm_pmu.o arm_pmu_platform.o
 obj-$(CONFIG_ARM_PMU_ACPI) += arm_pmu_acpi.o
+obj-$(CONFIG_ARM_SMMU_V3_PMU) += arm_smmuv3_pmu.o
 obj-$(CONFIG_HISI_PMU) += hisilicon/
 obj-$(CONFIG_QCOM_L2_PMU)	+= qcom_l2_pmu.o
 obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o
diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
new file mode 100644
index 0000000..c0924e5
--- /dev/null
+++ b/drivers/perf/arm_smmuv3_pmu.c
@@ -0,0 +1,776 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * This driver adds support for perf events to use the Performance
+ * Monitor Counter Groups (PMCG) associated with an SMMUv3 node
+ * to monitor that node.
+ *
+ * SMMUv3 PMCG devices are named as smmuv3_pmcg_<phys_addr_page> where
+ * <phys_addr_page> is the physical page address of the SMMU PMCG wrapped
+ * to 4K boundary. For example, the PMCG at 0xff88840000 is named
+ * smmuv3_pmcg_ff88840
+ *
+ * Filtering by stream id is done by specifying filtering parameters
+ * with the event. options are:
+ *   filter_enable    - 0 = no filtering, 1 = filtering enabled
+ *   filter_span      - 0 = exact match, 1 = pattern match
+ *   filter_stream_id - pattern to filter against
+ *
+ * To match a partial StreamID where the X most-significant bits must match
+ * but the Y least-significant bits might differ, STREAMID is programmed
+ * with a value that contains:
+ *  STREAMID[Y - 1] == 0.
+ *  STREAMID[Y - 2:0] == 1 (where Y > 1).
+ * The remainder of implemented bits of STREAMID (X bits, from bit Y upwards)
+ * contain a value to match from the corresponding bits of event StreamID.
+ *
+ * Example: perf stat -e smmuv3_pmcg_ff88840/transaction,filter_enable=1,
+ *                    filter_span=1,filter_stream_id=0x42/ -a netperf
+ * Applies filter pattern 0x42 to transaction events, which means events
+ * matching stream ids 0x42 and 0x43 are counted. Further filtering
+ * information is available in the SMMU documentation.
+ *
+ * SMMU events are not attributable to a CPU, so task mode and sampling
+ * are not supported.
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/cpuhotplug.h>
+#include <linux/cpumask.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/msi.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/smp.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#define SMMU_PMCG_EVCNTR0               0x0
+#define SMMU_PMCG_EVCNTR(n, stride)     (SMMU_PMCG_EVCNTR0 + (n) * (stride))
+#define SMMU_PMCG_EVTYPER0              0x400
+#define SMMU_PMCG_EVTYPER(n)            (SMMU_PMCG_EVTYPER0 + (n) * 4)
+#define SMMU_PMCG_SID_SPAN_SHIFT        29
+#define SMMU_PMCG_SMR0                  0xA00
+#define SMMU_PMCG_SMR(n)                (SMMU_PMCG_SMR0 + (n) * 4)
+#define SMMU_PMCG_CNTENSET0             0xC00
+#define SMMU_PMCG_CNTENCLR0             0xC20
+#define SMMU_PMCG_INTENSET0             0xC40
+#define SMMU_PMCG_INTENCLR0             0xC60
+#define SMMU_PMCG_OVSCLR0               0xC80
+#define SMMU_PMCG_OVSSET0               0xCC0
+#define SMMU_PMCG_CFGR                  0xE00
+#define SMMU_PMCG_CFGR_SID_FILTER_TYPE  BIT(23)
+#define SMMU_PMCG_CFGR_RELOC_CTRS       BIT(20)
+#define SMMU_PMCG_CFGR_SIZE             GENMASK(13, 8)
+#define SMMU_PMCG_CFGR_NCTR             GENMASK(5, 0)
+#define SMMU_PMCG_CR                    0xE04
+#define SMMU_PMCG_CR_ENABLE             BIT(0)
+#define SMMU_PMCG_CEID0                 0xE20
+#define SMMU_PMCG_CEID1                 0xE28
+#define SMMU_PMCG_IRQ_CTRL              0xE50
+#define SMMU_PMCG_IRQ_CTRL_IRQEN        BIT(0)
+#define SMMU_PMCG_IRQ_CFG0              0xE58
+
+#define SMMU_PMCG_DEFAULT_FILTER_SPAN   1
+#define SMMU_PMCG_DEFAULT_FILTER_SID    GENMASK(31, 0)
+
+#define SMMU_PMCG_MAX_COUNTERS          64
+#define SMMU_PMCG_ARCH_MAX_EVENTS       128
+
+#define SMMU_PMCG_PA_SHIFT              12
+
+static int cpuhp_state_num;
+
+struct smmu_pmu {
+	struct hlist_node node;
+	struct perf_event *events[SMMU_PMCG_MAX_COUNTERS];
+	DECLARE_BITMAP(used_counters, SMMU_PMCG_MAX_COUNTERS);
+	DECLARE_BITMAP(supported_events, SMMU_PMCG_ARCH_MAX_EVENTS);
+	unsigned int irq;
+	unsigned int on_cpu;
+	struct pmu pmu;
+	unsigned int num_counters;
+	struct device *dev;
+	void __iomem *reg_base;
+	void __iomem *reloc_base;
+	u64 counter_mask;
+	bool global_filter;
+	u32 global_filter_span;
+	u32 global_filter_sid;
+};
+
+#define to_smmu_pmu(p) (container_of(p, struct smmu_pmu, pmu))
+
+#define SMMU_PMU_EVENT_ATTR_EXTRACTOR(_name, _config, _start, _end)        \
+	static inline u32 get_##_name(struct perf_event *event)            \
+	{                                                                  \
+		return FIELD_GET(GENMASK_ULL(_end, _start),                \
+				 event->attr._config);                     \
+	}                                                                  \
+
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(event, config, 0, 15);
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_stream_id, config1, 0, 31);
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_span, config1, 32, 32);
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_enable, config1, 33, 33);
+
+static inline void smmu_pmu_enable(struct pmu *pmu)
+{
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(pmu);
+
+	writel(SMMU_PMCG_IRQ_CTRL_IRQEN,
+	       smmu_pmu->reg_base + SMMU_PMCG_IRQ_CTRL);
+	writel(SMMU_PMCG_CR_ENABLE, smmu_pmu->reg_base + SMMU_PMCG_CR);
+}
+
+static inline void smmu_pmu_disable(struct pmu *pmu)
+{
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(pmu);
+
+	writel(0, smmu_pmu->reg_base + SMMU_PMCG_CR);
+	writel(0, smmu_pmu->reg_base + SMMU_PMCG_IRQ_CTRL);
+}
+
+static inline void smmu_pmu_counter_set_value(struct smmu_pmu *smmu_pmu,
+					      u32 idx, u64 value)
+{
+	if (smmu_pmu->counter_mask & BIT(32))
+		writeq(value, smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 8));
+	else
+		writel(value, smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 4));
+}
+
+static inline u64 smmu_pmu_counter_get_value(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+	u64 value;
+
+	if (smmu_pmu->counter_mask & BIT(32))
+		value = readq(smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 8));
+	else
+		value = readl(smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 4));
+
+	return value;
+}
+
+static inline void smmu_pmu_counter_enable(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+	writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_CNTENSET0);
+}
+
+static inline void smmu_pmu_counter_disable(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+	writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_CNTENCLR0);
+}
+
+static inline void smmu_pmu_interrupt_enable(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+	writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_INTENSET0);
+}
+
+static inline void smmu_pmu_interrupt_disable(struct smmu_pmu *smmu_pmu,
+					      u32 idx)
+{
+	writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_INTENCLR0);
+}
+
+static inline void smmu_pmu_set_evtyper(struct smmu_pmu *smmu_pmu, u32 idx,
+					u32 val)
+{
+	writel(val, smmu_pmu->reg_base + SMMU_PMCG_EVTYPER(idx));
+}
+
+static inline void smmu_pmu_set_smr(struct smmu_pmu *smmu_pmu, u32 idx, u32 val)
+{
+	writel(val, smmu_pmu->reg_base + SMMU_PMCG_SMR(idx));
+}
+
+static void smmu_pmu_event_update(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+	u64 delta, prev, now;
+	u32 idx = hwc->idx;
+
+	do {
+		prev = local64_read(&hwc->prev_count);
+		now = smmu_pmu_counter_get_value(smmu_pmu, idx);
+	} while (local64_cmpxchg(&hwc->prev_count, prev, now) != prev);
+
+	/* handle overflow. */
+	delta = now - prev;
+	delta &= smmu_pmu->counter_mask;
+
+	local64_add(delta, &event->count);
+}
+
+static void smmu_pmu_set_period(struct smmu_pmu *smmu_pmu,
+				struct hw_perf_event *hwc)
+{
+	u32 idx = hwc->idx;
+	u64 new;
+
+	/*
+	 * We limit the max period to half the max counter value of the counter
+	 * size, so that even in the case of extreme interrupt latency the
+	 * counter will (hopefully) not wrap past its initial value.
+	 */
+	new = smmu_pmu->counter_mask >> 1;
+
+	local64_set(&hwc->prev_count, new);
+	smmu_pmu_counter_set_value(smmu_pmu, idx, new);
+}
+
+static void smmu_pmu_set_event_filter(struct perf_event *event,
+				      int idx, u32 span, u32 sid)
+{
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+	u32 evtyper;
+
+	evtyper = get_event(event) | span << SMMU_PMCG_SID_SPAN_SHIFT;
+	smmu_pmu_set_evtyper(smmu_pmu, idx, evtyper);
+	smmu_pmu_set_smr(smmu_pmu, idx, sid);
+}
+
+static int smmu_pmu_apply_event_filter(struct smmu_pmu *smmu_pmu,
+				       struct perf_event *event, int idx)
+{
+	u32 span, sid;
+	unsigned int num_ctrs = smmu_pmu->num_counters;
+	bool filter_en = !!get_filter_enable(event);
+
+	span = filter_en ? get_filter_span(event) :
+			   SMMU_PMCG_DEFAULT_FILTER_SPAN;
+	sid = filter_en ? get_filter_stream_id(event) :
+			   SMMU_PMCG_DEFAULT_FILTER_SID;
+
+	/* Support individual filter settings */
+	if (!smmu_pmu->global_filter) {
+		smmu_pmu_set_event_filter(event, idx, span, sid);
+		return 0;
+	}
+
+	/* Requested settings same as current global settings*/
+	if (span == smmu_pmu->global_filter_span &&
+	    sid == smmu_pmu->global_filter_sid)
+		return 0;
+
+	if (!bitmap_empty(smmu_pmu->used_counters, num_ctrs))
+		return -EAGAIN;
+
+	if (idx == 0) {
+		smmu_pmu_set_event_filter(event, idx, span, sid);
+		smmu_pmu->global_filter_span = span;
+		smmu_pmu->global_filter_sid = sid;
+		return 0;
+	}
+
+	return -EAGAIN;
+}
+
+static int smmu_pmu_get_event_idx(struct smmu_pmu *smmu_pmu,
+				  struct perf_event *event)
+{
+	int idx, err;
+	unsigned int num_ctrs = smmu_pmu->num_counters;
+
+	idx = find_first_zero_bit(smmu_pmu->used_counters, num_ctrs);
+	if (idx == num_ctrs)
+		/* The counters are all in use. */
+		return -EAGAIN;
+
+	err = smmu_pmu_apply_event_filter(smmu_pmu, event, idx);
+	if (err)
+		return err;
+
+	set_bit(idx, smmu_pmu->used_counters);
+
+	return idx;
+}
+
+/*
+ * Implementation of abstract pmu functionality required by
+ * the core perf events code.
+ */
+
+static int smmu_pmu_event_init(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+	struct device *dev = smmu_pmu->dev;
+	struct perf_event *sibling;
+	u16 event_id;
+
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	if (hwc->sample_period) {
+		dev_dbg(dev, "Sampling not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (event->cpu < 0) {
+		dev_dbg(dev, "Per-task mode not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	/* Verify specified event is supported on this PMU */
+	event_id = get_event(event);
+	if (event_id < SMMU_PMCG_ARCH_MAX_EVENTS &&
+	    (!test_bit(event_id, smmu_pmu->supported_events))) {
+		dev_dbg(dev, "Invalid event %d for this PMU\n", event_id);
+		return -EINVAL;
+	}
+
+	/* Don't allow groups with mixed PMUs, except for s/w events */
+	if (event->group_leader->pmu != event->pmu &&
+	    !is_software_event(event->group_leader)) {
+		dev_dbg(dev, "Can't create mixed PMU group\n");
+		return -EINVAL;
+	}
+
+	for_each_sibling_event(sibling, event->group_leader) {
+		if (sibling->pmu != event->pmu &&
+		    !is_software_event(sibling)) {
+			dev_dbg(dev, "Can't create mixed PMU group\n");
+			return -EINVAL;
+		}
+	}
+
+	hwc->idx = -1;
+
+	/*
+	 * Ensure all events are on the same cpu so all events are in the
+	 * same cpu context, to avoid races on pmu_enable etc.
+	 */
+	event->cpu = smmu_pmu->on_cpu;
+
+	return 0;
+}
+
+static void smmu_pmu_event_start(struct perf_event *event, int flags)
+{
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	int idx = hwc->idx;
+
+	hwc->state = 0;
+
+	smmu_pmu_set_period(smmu_pmu, hwc);
+
+	smmu_pmu_counter_enable(smmu_pmu, idx);
+}
+
+static void smmu_pmu_event_stop(struct perf_event *event, int flags)
+{
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	int idx = hwc->idx;
+
+	if (hwc->state & PERF_HES_STOPPED)
+		return;
+
+	smmu_pmu_counter_disable(smmu_pmu, idx);
+	/* As the counter gets updated on _start, ignore PERF_EF_UPDATE */
+	smmu_pmu_event_update(event);
+	hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+}
+
+static int smmu_pmu_event_add(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	int idx;
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+
+	idx = smmu_pmu_get_event_idx(smmu_pmu, event);
+	if (idx < 0)
+		return idx;
+
+	hwc->idx = idx;
+	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+	smmu_pmu->events[idx] = event;
+	local64_set(&hwc->prev_count, 0);
+
+	smmu_pmu_interrupt_enable(smmu_pmu, idx);
+
+	if (flags & PERF_EF_START)
+		smmu_pmu_event_start(event, flags);
+
+	/* Propagate changes to the userspace mapping. */
+	perf_event_update_userpage(event);
+
+	return 0;
+}
+
+static void smmu_pmu_event_del(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+	int idx = hwc->idx;
+
+	smmu_pmu_event_stop(event, flags | PERF_EF_UPDATE);
+	smmu_pmu_interrupt_disable(smmu_pmu, idx);
+	smmu_pmu->events[idx] = NULL;
+	clear_bit(idx, smmu_pmu->used_counters);
+
+	perf_event_update_userpage(event);
+}
+
+static void smmu_pmu_event_read(struct perf_event *event)
+{
+	smmu_pmu_event_update(event);
+}
+
+/* cpumask */
+
+static ssize_t smmu_pmu_cpumask_show(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(dev_get_drvdata(dev));
+
+	return cpumap_print_to_pagebuf(true, buf, cpumask_of(smmu_pmu->on_cpu));
+}
+
+static struct device_attribute smmu_pmu_cpumask_attr =
+		__ATTR(cpumask, 0444, smmu_pmu_cpumask_show, NULL);
+
+static struct attribute *smmu_pmu_cpumask_attrs[] = {
+	&smmu_pmu_cpumask_attr.attr,
+	NULL
+};
+
+static struct attribute_group smmu_pmu_cpumask_group = {
+	.attrs = smmu_pmu_cpumask_attrs,
+};
+
+/* Events */
+
+ssize_t smmu_pmu_event_show(struct device *dev,
+			    struct device_attribute *attr, char *page)
+{
+	struct perf_pmu_events_attr *pmu_attr;
+
+	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
+
+	return sprintf(page, "event=0x%02llx\n", pmu_attr->id);
+}
+
+#define SMMU_EVENT_ATTR(name, config) \
+	PMU_EVENT_ATTR(name, smmu_event_attr_##name, \
+		       config, smmu_pmu_event_show)
+SMMU_EVENT_ATTR(cycles, 0);
+SMMU_EVENT_ATTR(transaction, 1);
+SMMU_EVENT_ATTR(tlb_miss, 2);
+SMMU_EVENT_ATTR(config_cache_miss, 3);
+SMMU_EVENT_ATTR(trans_table_walk_access, 4);
+SMMU_EVENT_ATTR(config_struct_access, 5);
+SMMU_EVENT_ATTR(pcie_ats_trans_rq, 6);
+SMMU_EVENT_ATTR(pcie_ats_trans_passed, 7);
+
+static struct attribute *smmu_pmu_events[] = {
+	&smmu_event_attr_cycles.attr.attr,
+	&smmu_event_attr_transaction.attr.attr,
+	&smmu_event_attr_tlb_miss.attr.attr,
+	&smmu_event_attr_config_cache_miss.attr.attr,
+	&smmu_event_attr_trans_table_walk_access.attr.attr,
+	&smmu_event_attr_config_struct_access.attr.attr,
+	&smmu_event_attr_pcie_ats_trans_rq.attr.attr,
+	&smmu_event_attr_pcie_ats_trans_passed.attr.attr,
+	NULL
+};
+
+static umode_t smmu_pmu_event_is_visible(struct kobject *kobj,
+					 struct attribute *attr, int unused)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(dev_get_drvdata(dev));
+	struct perf_pmu_events_attr *pmu_attr;
+
+	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr.attr);
+
+	if (test_bit(pmu_attr->id, smmu_pmu->supported_events))
+		return attr->mode;
+
+	return 0;
+}
+
+static struct attribute_group smmu_pmu_events_group = {
+	.name = "events",
+	.attrs = smmu_pmu_events,
+	.is_visible = smmu_pmu_event_is_visible,
+};
+
+/* Formats */
+PMU_FORMAT_ATTR(event,		   "config:0-15");
+PMU_FORMAT_ATTR(filter_stream_id,  "config1:0-31");
+PMU_FORMAT_ATTR(filter_span,	   "config1:32");
+PMU_FORMAT_ATTR(filter_enable,	   "config1:33");
+
+static struct attribute *smmu_pmu_formats[] = {
+	&format_attr_event.attr,
+	&format_attr_filter_stream_id.attr,
+	&format_attr_filter_span.attr,
+	&format_attr_filter_enable.attr,
+	NULL
+};
+
+static struct attribute_group smmu_pmu_format_group = {
+	.name = "format",
+	.attrs = smmu_pmu_formats,
+};
+
+static const struct attribute_group *smmu_pmu_attr_grps[] = {
+	&smmu_pmu_cpumask_group,
+	&smmu_pmu_events_group,
+	&smmu_pmu_format_group,
+	NULL
+};
+
+/*
+ * Generic device handlers
+ */
+
+static int smmu_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+	struct smmu_pmu *smmu_pmu;
+	unsigned int target;
+
+	smmu_pmu = hlist_entry_safe(node, struct smmu_pmu, node);
+	if (cpu != smmu_pmu->on_cpu)
+		return 0;
+
+	target = cpumask_any_but(cpu_online_mask, cpu);
+	if (target >= nr_cpu_ids)
+		return 0;
+
+	perf_pmu_migrate_context(&smmu_pmu->pmu, cpu, target);
+	smmu_pmu->on_cpu = target;
+	WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(target)));
+
+	return 0;
+}
+
+static irqreturn_t smmu_pmu_handle_irq(int irq_num, void *data)
+{
+	struct smmu_pmu *smmu_pmu = data;
+	u64 ovsr;
+	unsigned int idx;
+
+	ovsr = readq(smmu_pmu->reloc_base + SMMU_PMCG_OVSSET0);
+	if (!ovsr)
+		return IRQ_NONE;
+
+	writeq(ovsr, smmu_pmu->reloc_base + SMMU_PMCG_OVSCLR0);
+
+	for_each_set_bit(idx, (unsigned long *)&ovsr, smmu_pmu->num_counters) {
+		struct perf_event *event = smmu_pmu->events[idx];
+		struct hw_perf_event *hwc;
+
+		if (WARN_ON_ONCE(!event))
+			continue;
+
+		smmu_pmu_event_update(event);
+		hwc = &event->hw;
+
+		smmu_pmu_set_period(smmu_pmu, hwc);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int smmu_pmu_setup_irq(struct smmu_pmu *pmu)
+{
+	unsigned long flags = IRQF_NOBALANCING | IRQF_SHARED | IRQF_NO_THREAD;
+	int irq, ret = -ENXIO;
+
+	irq = pmu->irq;
+	if (irq)
+		ret = devm_request_irq(pmu->dev, irq, smmu_pmu_handle_irq,
+				       flags, "smmuv3-pmu", pmu);
+	return ret;
+}
+
+static void smmu_pmu_reset(struct smmu_pmu *smmu_pmu)
+{
+	u64 counter_present_mask = GENMASK_ULL(smmu_pmu->num_counters - 1, 0);
+
+	smmu_pmu_disable(&smmu_pmu->pmu);
+
+	/* Disable counter and interrupt */
+	writeq_relaxed(counter_present_mask,
+		       smmu_pmu->reg_base + SMMU_PMCG_CNTENCLR0);
+	writeq_relaxed(counter_present_mask,
+		       smmu_pmu->reg_base + SMMU_PMCG_INTENCLR0);
+	writeq_relaxed(counter_present_mask,
+		       smmu_pmu->reloc_base + SMMU_PMCG_OVSCLR0);
+}
+
+static int smmu_pmu_probe(struct platform_device *pdev)
+{
+	struct smmu_pmu *smmu_pmu;
+	struct resource *res_0, *res_1;
+	u32 cfgr, reg_size;
+	u64 ceid_64[2];
+	int irq, err;
+	char *name;
+	struct device *dev = &pdev->dev;
+
+	smmu_pmu = devm_kzalloc(dev, sizeof(*smmu_pmu), GFP_KERNEL);
+	if (!smmu_pmu)
+		return -ENOMEM;
+
+	smmu_pmu->dev = dev;
+	platform_set_drvdata(pdev, smmu_pmu);
+
+	smmu_pmu->pmu = (struct pmu) {
+		.task_ctx_nr    = perf_invalid_context,
+		.pmu_enable	= smmu_pmu_enable,
+		.pmu_disable	= smmu_pmu_disable,
+		.event_init	= smmu_pmu_event_init,
+		.add		= smmu_pmu_event_add,
+		.del		= smmu_pmu_event_del,
+		.start		= smmu_pmu_event_start,
+		.stop		= smmu_pmu_event_stop,
+		.read		= smmu_pmu_event_read,
+		.attr_groups	= smmu_pmu_attr_grps,
+		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
+	};
+
+	res_0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	smmu_pmu->reg_base = devm_ioremap_resource(dev, res_0);
+	if (IS_ERR(smmu_pmu->reg_base))
+		return PTR_ERR(smmu_pmu->reg_base);
+
+	cfgr = readl_relaxed(smmu_pmu->reg_base + SMMU_PMCG_CFGR);
+
+	/* Determine if page 1 is present */
+	if (cfgr & SMMU_PMCG_CFGR_RELOC_CTRS) {
+		res_1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+		smmu_pmu->reloc_base = devm_ioremap_resource(dev, res_1);
+		if (IS_ERR(smmu_pmu->reloc_base))
+			return PTR_ERR(smmu_pmu->reloc_base);
+	} else {
+		smmu_pmu->reloc_base = smmu_pmu->reg_base;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq > 0)
+		smmu_pmu->irq = irq;
+
+	ceid_64[0] = readq_relaxed(smmu_pmu->reg_base + SMMU_PMCG_CEID0);
+	ceid_64[1] = readq_relaxed(smmu_pmu->reg_base + SMMU_PMCG_CEID1);
+	bitmap_from_arr32(smmu_pmu->supported_events, (u32 *)ceid_64,
+			  SMMU_PMCG_ARCH_MAX_EVENTS);
+
+	smmu_pmu->num_counters = FIELD_GET(SMMU_PMCG_CFGR_NCTR, cfgr) + 1;
+
+	smmu_pmu->global_filter = !!(cfgr & SMMU_PMCG_CFGR_SID_FILTER_TYPE);
+
+	reg_size = FIELD_GET(SMMU_PMCG_CFGR_SIZE, cfgr);
+	smmu_pmu->counter_mask = GENMASK_ULL(reg_size, 0);
+
+	smmu_pmu_reset(smmu_pmu);
+
+	err = smmu_pmu_setup_irq(smmu_pmu);
+	if (err) {
+		dev_err(dev, "Setup irq failed, PMU @%pa\n", &res_0->start);
+		return err;
+	}
+
+	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "smmuv3_pmcg_%llx",
+			      (res_0->start) >> SMMU_PMCG_PA_SHIFT);
+	if (!name) {
+		dev_err(dev, "Create name failed, PMU @%pa\n", &res_0->start);
+		return -EINVAL;
+	}
+
+	/* Pick one CPU to be the preferred one to use */
+	smmu_pmu->on_cpu = raw_smp_processor_id();
+	WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(smmu_pmu->on_cpu)));
+
+	err = cpuhp_state_add_instance_nocalls(cpuhp_state_num,
+					       &smmu_pmu->node);
+	if (err) {
+		dev_err(dev, "Error %d registering hotplug, PMU @%pa\n",
+			err, &res_0->start);
+		goto out_cpuhp_err;
+	}
+
+	err = perf_pmu_register(&smmu_pmu->pmu, name, -1);
+	if (err) {
+		dev_err(dev, "Error %d registering PMU @%pa\n",
+			err, &res_0->start);
+		goto out_unregister;
+	}
+
+	dev_info(dev, "Registered PMU @ %pa using %d counters with %s filter settings\n",
+		 &res_0->start, smmu_pmu->num_counters,
+		 smmu_pmu->global_filter ? "Global(Counter0)" :
+		 "Individual");
+
+	return 0;
+
+out_unregister:
+	cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &smmu_pmu->node);
+out_cpuhp_err:
+	put_cpu();
+	return err;
+}
+
+static int smmu_pmu_remove(struct platform_device *pdev)
+{
+	struct smmu_pmu *smmu_pmu = platform_get_drvdata(pdev);
+
+	perf_pmu_unregister(&smmu_pmu->pmu);
+	cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &smmu_pmu->node);
+
+	return 0;
+}
+
+static void smmu_pmu_shutdown(struct platform_device *pdev)
+{
+	struct smmu_pmu *smmu_pmu = platform_get_drvdata(pdev);
+
+	smmu_pmu_disable(&smmu_pmu->pmu);
+}
+
+static struct platform_driver smmu_pmu_driver = {
+	.driver = {
+		.name = "arm-smmu-v3-pmcg",
+	},
+	.probe = smmu_pmu_probe,
+	.remove = smmu_pmu_remove,
+	.shutdown = smmu_pmu_shutdown,
+};
+
+static int __init arm_smmu_pmu_init(void)
+{
+	cpuhp_state_num = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
+						  "perf/arm/pmcg:online",
+						  NULL,
+						  smmu_pmu_offline_cpu);
+	if (cpuhp_state_num < 0)
+		return cpuhp_state_num;
+
+	return platform_driver_register(&smmu_pmu_driver);
+}
+module_init(arm_smmu_pmu_init);
+
+static void __exit arm_smmu_pmu_exit(void)
+{
+	platform_driver_unregister(&smmu_pmu_driver);
+	cpuhp_remove_multi_state(cpuhp_state_num);
+}
+
+module_exit(arm_smmu_pmu_exit);
+
+MODULE_DESCRIPTION("PMU driver for ARM SMMUv3 Performance Monitors Extension");
+MODULE_AUTHOR("Neil Leeder <nleeder@codeaurora.org>");
+MODULE_AUTHOR("Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>");
+MODULE_LICENSE("GPL v2");