[PATCH 0/6 v4] arm64/perf: Add ACPI support

[PATCH 0/6 v4] arm64/perf: Add ACPI support

[Jeremy Linton]

v3->v4:
Correct build issues with ARM (!ARM64) kernels.
Add ThunderX to list of PMU types.

v3:
Enable ARM performance monitoring units on ACPI/arm64 machines.

This patch expands and reworks the patches published by Mark Salter
in order to clean up a few of the previous review comments, as well as
add support for newer CPUs and big/little configurations.

I've been testing this patch in concert with an assortment of ACPI
patches to enable things like PCIe. Its been tested on juno, seattle
and some xgene systems.

Thanks,

*** BLURB HERE ***

Jeremy Linton (3):
  arm: arm64: Add routine to determine cpuid of other cpus
  arm64: pmu: Add ACPI support for A72 and ThunderX
  arm64: pmu: Detect multiple PMU types in an ACPI system

Mark Salter (3):
  arm: pmu: Fix non-devicetree probing
  arm64: pmu: add fallback probe table
  arm64: pmu: Add support for probing with ACPI

 arch/arm/include/asm/cputype.h   |   4 +
 arch/arm64/include/asm/cputype.h |   4 +
 arch/arm64/kernel/perf_event.c   |  12 ++-
 arch/arm64/kernel/smp.c          |   5 +
 drivers/perf/Kconfig             |   4 +
 drivers/perf/Makefile            |   1 +
 drivers/perf/arm_pmu.c           |  51 ++++++++--
 drivers/perf/arm_pmu_acpi.c      | 213 +++++++++++++++++++++++++++++++++++++++
 include/linux/perf/arm_pmu.h     |  10 ++
 9 files changed, 293 insertions(+), 11 deletions(-)
 create mode 100644 drivers/perf/arm_pmu_acpi.c

-- 
2.4.3

[PATCH 1/6] arm: pmu: Fix non-devicetree probing

[Jeremy Linton]

From: Mark Salter <msalter@redhat.com>

There is a problem in the non-devicetree PMU probing where some
probe functions may get the number of supported events through
smp_call_function_any() using the arm_pmu supported_cpus mask.
But at the time the probe function is called, the supported_cpus
mask is empty so the call fails. This patch makes sure the mask
is set before calling the init function rather than after.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
 drivers/perf/arm_pmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 32346b5..49fa845 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -997,8 +997,8 @@ int arm_pmu_device_probe(struct platform_device *pdev,
 		if (!ret)
 			ret = init_fn(pmu);
 	} else {
-		ret = probe_current_pmu(pmu, probe_table);
 		cpumask_setall(&pmu->supported_cpus);
+		ret = probe_current_pmu(pmu, probe_table);
 	}
 
 	if (ret) {
-- 
2.4.3

[PATCH 2/6] arm64: pmu: add fallback probe table

[Jeremy Linton]

From: Mark Salter <msalter@redhat.com>

In preparation for ACPI support, add a pmu_probe_info table to
the arm_pmu_device_probe() call. This table gets used when
probing in the absence of a devicetree node for PMU.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
 arch/arm64/kernel/perf_event.c | 10 +++++++++-
 include/linux/perf/arm_pmu.h   |  3 +++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index f419a7c..8f12eac 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -867,9 +867,17 @@ static const struct of_device_id armv8_pmu_of_device_ids[] = {
 	{},
 };
 
+static const struct pmu_probe_info armv8_pmu_probe_table[] = {
+	ARMV8_PMU_PART_PROBE(ARM_CPU_PART_CORTEX_A53, armv8_a53_pmu_init),
+	ARMV8_PMU_PART_PROBE(ARM_CPU_PART_CORTEX_A57, armv8_a57_pmu_init),
+	PMU_PROBE(0, 0, armv8_pmuv3_init), /* if all else fails... */
+	{ /* sentinel value */ }
+};
+
 static int armv8_pmu_device_probe(struct platform_device *pdev)
 {
-	return arm_pmu_device_probe(pdev, armv8_pmu_of_device_ids, NULL);
+	return arm_pmu_device_probe(pdev, armv8_pmu_of_device_ids,
+				    armv8_pmu_probe_table);
 }
 
 static struct platform_driver armv8_pmu_driver = {
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 4196c90..495332f 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -145,6 +145,9 @@ struct pmu_probe_info {
 #define XSCALE_PMU_PROBE(_version, _fn) \
 	PMU_PROBE(ARM_CPU_IMP_INTEL << 24 | _version, ARM_PMU_XSCALE_MASK, _fn)
 
+#define ARMV8_PMU_PART_PROBE(_part, _fn) \
+	PMU_PROBE((_part) << MIDR_PARTNUM_SHIFT, MIDR_PARTNUM_MASK, _fn)
+
 int arm_pmu_device_probe(struct platform_device *pdev,
 			 const struct of_device_id *of_table,
 			 const struct pmu_probe_info *probe_table);
-- 
2.4.3

[PATCH 3/6] arm64: pmu: Add support for probing with ACPI

[Jeremy Linton]

From: Mark Salter <msalter@redhat.com>

In the case of ACPI, the PMU IRQ information is contained in the
MADT table. Also, since the PMU does not exist as a device in the
ACPI DSDT table, it is necessary to create a platform device so
that the appropriate driver probing is triggered.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
 arch/arm64/kernel/smp.c      |   5 ++
 drivers/perf/Kconfig         |   4 ++
 drivers/perf/Makefile        |   1 +
 drivers/perf/arm_pmu_acpi.c  | 125 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/perf/arm_pmu.h |   7 +++
 5 files changed, 142 insertions(+)
 create mode 100644 drivers/perf/arm_pmu_acpi.c

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index b2d5f4e..c6f2c53 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -37,6 +37,7 @@
 #include <linux/completion.h>
 #include <linux/of.h>
 #include <linux/irq_work.h>
+#include <linux/perf/arm_pmu.h>
 
 #include <asm/alternative.h>
 #include <asm/atomic.h>
@@ -502,6 +503,7 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
 			return;
 		}
 		bootcpu_valid = true;
+		arm_pmu_parse_acpi(0, processor);
 		return;
 	}
 
@@ -522,6 +524,9 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
 	 */
 	acpi_set_mailbox_entry(cpu_count, processor);
 
+	/* get PMU irq info */
+	arm_pmu_parse_acpi(cpu_count, processor);
+
 	cpu_count++;
 }
 
diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index 04e2653..818fa3b 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -12,4 +12,8 @@ config ARM_PMU
 	  Say y if you want to use CPU performance monitors on ARM-based
 	  systems.
 
+config ARM_PMU_ACPI
+	def_bool y
+	depends on ARM_PMU && ACPI
+
 endmenu
diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
index acd2397..fd8090d 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_ARM_PMU) += arm_pmu.o
+obj-$(CONFIG_ARM_PMU_ACPI) += arm_pmu_acpi.o
diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
new file mode 100644
index 0000000..722f4ca
--- /dev/null
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -0,0 +1,125 @@
+/*
+ * PMU support
+ *
+ * Copyright (C) 2015 Red Hat Inc.
+ * Author: Mark Salter <msalter@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include <linux/perf/arm_pmu.h>
+#include <linux/platform_device.h>
+#include <linux/acpi.h>
+#include <linux/irq.h>
+#include <linux/irqdesc.h>
+
+#define PMU_PDEV_NAME "armv8-pmu"
+
+struct pmu_irq {
+	int gsi;
+	int trigger;
+};
+
+static struct pmu_irq pmu_irqs[NR_CPUS] __initdata;
+
+void __init arm_pmu_parse_acpi(int cpu, struct acpi_madt_generic_interrupt *gic)
+{
+	pmu_irqs[cpu].gsi = gic->performance_interrupt;
+	if (gic->flags & ACPI_MADT_PERFORMANCE_IRQ_MODE)
+		pmu_irqs[cpu].trigger = ACPI_EDGE_SENSITIVE;
+	else
+		pmu_irqs[cpu].trigger = ACPI_LEVEL_SENSITIVE;
+}
+
+#ifndef CONFIG_SMP
+/*
+ * In !SMP case, we parse for boot CPU IRQ here.
+ */
+static int __init acpi_parse_pmu_irqs(struct acpi_subtable_header *header,
+				      const unsigned long end)
+{
+	struct acpi_madt_generic_interrupt *gic;
+
+	gic = (struct acpi_madt_generic_interrupt *)header;
+
+	if (cpu_logical_map(0) == (gic->arm_mpidr & MPIDR_HWID_BITMASK))
+		arm_pmu_parse_acpi(0, gic);
+
+	return 0;
+}
+
+static void __init acpi_parse_boot_cpu(void)
+{
+	count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
+				      acpi_parse_pmu_irqs, 0);
+}
+#else
+#define acpi_parse_boot_cpu() do {} while (0)
+#endif
+
+static int __init pmu_acpi_init(void)
+{
+	struct platform_device *pdev;
+	struct pmu_irq *pirq = pmu_irqs;
+	struct resource	*res, *r;
+	int err = -ENOMEM;
+	int i, count, irq;
+
+	if (acpi_disabled)
+		return 0;
+
+	acpi_parse_boot_cpu();
+
+	/* Must have irq for boot boot cpu, at least */
+	if (pirq->gsi == 0)
+		return -EINVAL;
+
+	irq = acpi_register_gsi(NULL, pirq->gsi, pirq->trigger,
+				ACPI_ACTIVE_HIGH);
+
+	if (irq_is_percpu(irq))
+		count = 1;
+	else
+		for (i = 1, count = 1; i < NR_CPUS; i++)
+			if (pmu_irqs[i].gsi)
+				++count;
+
+	pdev = platform_device_alloc(PMU_PDEV_NAME, -1);
+	if (!pdev)
+		goto err_free_gsi;
+
+	res = kcalloc(count, sizeof(*res), GFP_KERNEL);
+	if (!res)
+		goto err_free_device;
+
+	for (i = 0, r = res; i < count; i++, pirq++, r++) {
+		if (i)
+			irq = acpi_register_gsi(NULL, pirq->gsi, pirq->trigger,
+						ACPI_ACTIVE_HIGH);
+		r->start = r->end = irq;
+		r->flags = IORESOURCE_IRQ;
+		if (pirq->trigger == ACPI_EDGE_SENSITIVE)
+			r->flags |= IORESOURCE_IRQ_HIGHEDGE;
+		else
+			r->flags |= IORESOURCE_IRQ_HIGHLEVEL;
+	}
+
+	err = platform_device_add_resources(pdev, res, count);
+	if (!err)
+		err = platform_device_add(pdev);
+	kfree(res);
+	if (!err)
+		return 0;
+
+err_free_device:
+	platform_device_put(pdev);
+
+err_free_gsi:
+	for (i = 0; i < count; i++)
+		acpi_unregister_gsi(pmu_irqs[i].gsi);
+
+	return err;
+}
+arch_initcall(pmu_acpi_init);
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 495332f..d002269 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -154,4 +154,11 @@ int arm_pmu_device_probe(struct platform_device *pdev,
 
 #endif /* CONFIG_ARM_PMU */
 
+#ifdef CONFIG_ARM_PMU_ACPI
+struct acpi_madt_generic_interrupt;
+void arm_pmu_parse_acpi(int cpu, struct acpi_madt_generic_interrupt *gic);
+#else
+#define arm_pmu_parse_acpi(a, b) do { } while (0)
+#endif /* CONFIG_ARM_PMU_ACPI */
+
 #endif /* __ARM_PMU_H__ */
-- 
2.4.3

[PATCH 4/6] arm: arm64: Add routine to determine cpuid of other cpus

[Jeremy Linton]

It is helpful if we can read the cpuid/midr of other CPUs
in the system independent of arm/arm64.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
 arch/arm/include/asm/cputype.h   | 4 ++++
 arch/arm64/include/asm/cputype.h | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index b23c6c8..274baf4 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -208,6 +208,10 @@ static inline unsigned int __attribute_const__ read_cpuid_mpidr(void)
 	return read_cpuid(CPUID_MPIDR);
 }
 
+#define read_specific_cpuid(cpu_num) per_cpu_ptr(&cpu_data, cpu_num)->cpuid
+
+
+
 /*
  * Intel's XScale3 core supports some v6 features (supersections, L2)
  * but advertises itself as v5 as it does not support the v6 ISA.  For
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 87e1985..76423a7 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -126,6 +126,9 @@ static inline u32 __attribute_const__ read_cpuid_cachetype(void)
 {
 	return read_cpuid(CTR_EL0);
 }
+
+#define read_specific_cpuid(cpu_num) per_cpu_ptr(&cpu_data, cpu_num)->reg_midr
+
 #endif /* __ASSEMBLY__ */
 
 #endif
-- 
2.4.3

[PATCH 5/6] arm64: pmu: Add ACPI support for A72 and ThunderX

[Jeremy Linton]

Update the armv8_pmu_probe_table so that ACPI systems can
identify the A72 and ThunderX PMUs.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
 arch/arm64/include/asm/cputype.h | 1 +
 arch/arm64/kernel/perf_event.c   | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 76423a7..2688755 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -74,6 +74,7 @@
 
 #define ARM_CPU_PART_AEM_V8		0xD0F
 #define ARM_CPU_PART_FOUNDATION		0xD00
+#define ARM_CPU_PART_CORTEX_A72		0xD08
 #define ARM_CPU_PART_CORTEX_A57		0xD07
 #define ARM_CPU_PART_CORTEX_A53		0xD03
 
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 8f12eac..e14ac54 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -870,6 +870,8 @@ static const struct of_device_id armv8_pmu_of_device_ids[] = {
 static const struct pmu_probe_info armv8_pmu_probe_table[] = {
 	ARMV8_PMU_PART_PROBE(ARM_CPU_PART_CORTEX_A53, armv8_a53_pmu_init),
 	ARMV8_PMU_PART_PROBE(ARM_CPU_PART_CORTEX_A57, armv8_a57_pmu_init),
+	ARMV8_PMU_PART_PROBE(ARM_CPU_PART_CORTEX_A72, armv8_a72_pmu_init),
+	ARMV8_PMU_PART_PROBE(CAVIUM_CPU_PART_THUNDERX, armv8_thunder_pmu_init),
 	PMU_PROBE(0, 0, armv8_pmuv3_init), /* if all else fails... */
 	{ /* sentinel value */ }
 };
-- 
2.4.3

[PATCH 6/6] arm64: pmu: Detect multiple PMU types in an ACPI system

[Jeremy Linton]

Its possible that an ACPI system has multiple CPU types in it
with differing PMU counters. Detect that case and attempt
to instantiate more than one set of counters.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
 drivers/perf/arm_pmu.c      |  51 ++++++++--
 drivers/perf/arm_pmu_acpi.c | 230 ++++++++++++++++++++++++++++++--------------
 2 files changed, 200 insertions(+), 81 deletions(-)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 49fa845..524c8ae 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -11,6 +11,7 @@
  */
 #define pr_fmt(fmt) "hw perfevents: " fmt
 
+#include <linux/acpi.h>
 #include <linux/bitmap.h>
 #include <linux/cpumask.h>
 #include <linux/cpu_pm.h>
@@ -24,6 +25,7 @@
 #include <linux/irq.h>
 #include <linux/irqdesc.h>
 
+#include <asm/cpu.h>
 #include <asm/cputype.h>
 #include <asm/irq_regs.h>
 
@@ -853,25 +855,50 @@ static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
 }
 
 /*
- * CPU PMU identification and probing.
+ * CPU PMU identification and probing. Its possible to have
+ * multiple CPU types in an ARM machine. Assure that we are
+ * picking the right PMU types based on the CPU in question
  */
-static int probe_current_pmu(struct arm_pmu *pmu,
-			     const struct pmu_probe_info *info)
+static int probe_plat_pmu(struct arm_pmu *pmu,
+			     const struct pmu_probe_info *info,
+			     unsigned int pmuid)
 {
-	int cpu = get_cpu();
-	unsigned int cpuid = read_cpuid_id();
 	int ret = -ENODEV;
+	int cpu;
+	int aff_ctr = 0;
+	struct platform_device *pdev = pmu->plat_device;
+	int irq = platform_get_irq(pdev, 0);
 
-	pr_info("probing PMU on CPU %d\n", cpu);
+	if (irq >= 0 && !irq_is_percpu(irq)) {
+		pmu->irq_affinity = kcalloc(pdev->num_resources, sizeof(int),
+					    GFP_KERNEL);
+		if (!pmu->irq_affinity)
+			return -ENOMEM;
+	}
 
+	for_each_possible_cpu(cpu) {
+		unsigned int cpuid = read_specific_cpuid(cpu);
+
+		if (cpuid == pmuid) {
+			cpumask_set_cpu(cpu, &pmu->supported_cpus);
+			pr_devel("enable pmu on cpu %d\n", cpu);
+			if (pmu->irq_affinity) {
+				pmu->irq_affinity[aff_ctr] = cpu;
+				aff_ctr++;
+			}
+		}
+	}
+
+	pr_debug("probing PMU %X\n", pmuid);
+	/* find the type of PMU given the CPU */
 	for (; info->init != NULL; info++) {
-		if ((cpuid & info->mask) != info->cpuid)
+		if ((pmuid & info->mask) != info->cpuid)
 			continue;
+		pr_devel("Found PMU\n");
 		ret = info->init(pmu);
 		break;
 	}
 
-	put_cpu();
 	return ret;
 }
 
@@ -997,8 +1024,12 @@ int arm_pmu_device_probe(struct platform_device *pdev,
 		if (!ret)
 			ret = init_fn(pmu);
 	} else {
-		cpumask_setall(&pmu->supported_cpus);
-		ret = probe_current_pmu(pmu, probe_table);
+		if (acpi_disabled) {
+			/* use the boot cpu. */
+			ret = probe_plat_pmu(pmu, probe_table,
+					     read_specific_cpuid(0));
+		} else
+			ret = probe_plat_pmu(pmu, probe_table, pdev->id);
 	}
 
 	if (ret) {
diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index 722f4ca..4cc1599 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -2,6 +2,7 @@
  * PMU support
  *
  * Copyright (C) 2015 Red Hat Inc.
+ * Copyright (C) 2016 ARM Ltd.
  * Author: Mark Salter <msalter@redhat.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2.  See
@@ -9,21 +10,35 @@
  *
  */
 
+#define pr_fmt(fmt) "ACPI-PMU: " fmt
 #include <linux/perf/arm_pmu.h>
 #include <linux/platform_device.h>
 #include <linux/acpi.h>
 #include <linux/irq.h>
 #include <linux/irqdesc.h>
 
+#include <asm/cpu.h>
+
 #define PMU_PDEV_NAME "armv8-pmu"
 
 struct pmu_irq {
-	int gsi;
-	int trigger;
+	int  gsi;
+	int  trigger;
+	bool registered;
+};
+
+struct pmu_types {
+	int cpu_type;
+	int cpu_count;
 };
 
 static struct pmu_irq pmu_irqs[NR_CPUS] __initdata;
 
+/*
+ * called from acpi_map_gic_cpu_interface()'s MADT parsing callback during boot
+ * this routine saves off the GSI's and their trigger state for use when we are
+ * ready to build the PMU platform device.
+*/
 void __init arm_pmu_parse_acpi(int cpu, struct acpi_madt_generic_interrupt *gic)
 {
 	pmu_irqs[cpu].gsi = gic->performance_interrupt;
@@ -31,95 +46,168 @@ void __init arm_pmu_parse_acpi(int cpu, struct acpi_madt_generic_interrupt *gic)
 		pmu_irqs[cpu].trigger = ACPI_EDGE_SENSITIVE;
 	else
 		pmu_irqs[cpu].trigger = ACPI_LEVEL_SENSITIVE;
+	pr_info("Assign CPU %d girq %d level %d\n", cpu, pmu_irqs[cpu].gsi,
+						   pmu_irqs[cpu].trigger);
 }
 
-#ifndef CONFIG_SMP
-/*
- * In !SMP case, we parse for boot CPU IRQ here.
- */
-static int __init acpi_parse_pmu_irqs(struct acpi_subtable_header *header,
-				      const unsigned long end)
-{
-	struct acpi_madt_generic_interrupt *gic;
-
-	gic = (struct acpi_madt_generic_interrupt *)header;
-
-	if (cpu_logical_map(0) == (gic->arm_mpidr & MPIDR_HWID_BITMASK))
-		arm_pmu_parse_acpi(0, gic);
-
-	return 0;
-}
-
-static void __init acpi_parse_boot_cpu(void)
+/* count number and type of CPU's in system */
+static void __init arm_pmu_acpi_determine_cpu_types(struct pmu_types *pmus)
 {
-	count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
-				      acpi_parse_pmu_irqs, 0);
+	int i, j;
+
+	for_each_possible_cpu(i) {
+		struct cpuinfo_arm64 *cinfo = per_cpu_ptr(&cpu_data, i);
+
+		pr_devel("Present CPU %d is a %X\n", i,
+					       MIDR_PARTNUM(cinfo->reg_midr));
+		for (j = 0; j < num_possible_cpus(); j++) {
+			if (pmus[j].cpu_type == MIDR_PARTNUM(cinfo->reg_midr)) {
+				pmus[j].cpu_count++;
+				break;
+			}
+			if (pmus[j].cpu_count == 0) {
+				pmus[j].cpu_type = MIDR_PARTNUM(cinfo->reg_midr);
+				pmus[j].cpu_count++;
+				break;
+			}
+		}
+	}
 }
-#else
-#define acpi_parse_boot_cpu() do {} while (0)
-#endif
 
-static int __init pmu_acpi_init(void)
+static int __init arm_pmu_acpi_register_pmu(int count, struct resource *res,
+					    int last_cpu_id)
 {
-	struct platform_device *pdev;
-	struct pmu_irq *pirq = pmu_irqs;
-	struct resource	*res, *r;
+	int i;
 	int err = -ENOMEM;
-	int i, count, irq;
+	bool free_gsi = false;
+	struct platform_device *pdev;
 
-	if (acpi_disabled)
-		return 0;
+	if (count) {
+		pdev = platform_device_alloc(PMU_PDEV_NAME, last_cpu_id);
+
+		if (pdev) {
+			err = platform_device_add_resources(pdev,
+							    res, count);
+			if (!err) {
+				err = platform_device_add(pdev);
+				if (err) {
+					pr_warn("Unable to register PMU device\n");
+					free_gsi = true;
+				}
+			} else {
+				pr_warn("Unable to add resources to device\n");
+				free_gsi = true;
+				platform_device_put(pdev);
+			}
+		} else {
+			pr_warn("Unable to allocate platform device\n");
+			free_gsi = true;
+		}
+	}
 
-	acpi_parse_boot_cpu();
+	/* unmark (and possibly unregister) registered GSIs */
+	for_each_possible_cpu(i) {
+		if (pmu_irqs[i].registered) {
+			if (free_gsi)
+				acpi_unregister_gsi(pmu_irqs[i].gsi);
+			pmu_irqs[i].registered = false;
+		}
+	}
 
-	/* Must have irq for boot boot cpu, at least */
-	if (pirq->gsi == 0)
-		return -EINVAL;
+	return err;
+}
 
-	irq = acpi_register_gsi(NULL, pirq->gsi, pirq->trigger,
-				ACPI_ACTIVE_HIGH);
+/*
+ * For the given cpu/pmu type, walk all known GSIs, register them, and add
+ * them to the resource structure. Return the number of GSI's contained
+ * in the res structure, and the id of the last CPU/PMU we added.
+ */
+static int __init arm_pmu_acpi_gsi_res(struct pmu_types *pmus,
+				       struct resource *res, int *last_cpu_id)
+{
+	int i, count;
+	int irq;
+
+	pr_info("Setting up %d PMUs for CPU type %X\n", pmus->cpu_count,
+							pmus->cpu_type);
+	/* lets group all the PMU's from similar CPU's together */
+	count = 0;
+	for_each_possible_cpu(i) {
+		struct cpuinfo_arm64 *cinfo = per_cpu_ptr(&cpu_data, i);
+
+		if (pmus->cpu_type == MIDR_PARTNUM(cinfo->reg_midr)) {
+			pr_devel("Setting up CPU %d\n", i);
+			if (pmu_irqs[i].gsi == 0)
+				continue;
+
+			irq = acpi_register_gsi(NULL, pmu_irqs[i].gsi,
+						pmu_irqs[i].trigger,
+						ACPI_ACTIVE_HIGH);
 
-	if (irq_is_percpu(irq))
-		count = 1;
-	else
-		for (i = 1, count = 1; i < NR_CPUS; i++)
-			if (pmu_irqs[i].gsi)
-				++count;
+			res[count].start = res[count].end = irq;
+			res[count].flags = IORESOURCE_IRQ;
 
-	pdev = platform_device_alloc(PMU_PDEV_NAME, -1);
-	if (!pdev)
-		goto err_free_gsi;
+			if (pmu_irqs[i].trigger == ACPI_EDGE_SENSITIVE)
+				res[count].flags |= IORESOURCE_IRQ_HIGHEDGE;
+			else
+				res[count].flags |= IORESOURCE_IRQ_HIGHLEVEL;
 
-	res = kcalloc(count, sizeof(*res), GFP_KERNEL);
-	if (!res)
-		goto err_free_device;
+			pmu_irqs[i].registered = true;
+			count++;
+			(*last_cpu_id) = cinfo->reg_midr;
 
-	for (i = 0, r = res; i < count; i++, pirq++, r++) {
-		if (i)
-			irq = acpi_register_gsi(NULL, pirq->gsi, pirq->trigger,
-						ACPI_ACTIVE_HIGH);
-		r->start = r->end = irq;
-		r->flags = IORESOURCE_IRQ;
-		if (pirq->trigger == ACPI_EDGE_SENSITIVE)
-			r->flags |= IORESOURCE_IRQ_HIGHEDGE;
-		else
-			r->flags |= IORESOURCE_IRQ_HIGHLEVEL;
+			if (irq_is_percpu(irq))
+				pr_debug("PPI detected\n");
+		}
 	}
+	return count;
+}
 
-	err = platform_device_add_resources(pdev, res, count);
-	if (!err)
-		err = platform_device_add(pdev);
-	kfree(res);
-	if (!err)
-		return 0;
+static int __init pmu_acpi_init(void)
+{
+	struct resource	*res;
+	int err = -ENOMEM;
+	int count;
+	int j, last_cpu_id;
+	struct pmu_types *pmus;
 
-err_free_device:
-	platform_device_put(pdev);
+	pr_debug("Prepare registration\n");
+	if (acpi_disabled)
+		return 0;
 
-err_free_gsi:
-	for (i = 0; i < count; i++)
-		acpi_unregister_gsi(pmu_irqs[i].gsi);
+	pmus = kcalloc(num_possible_cpus(), sizeof(struct pmu_types),
+		       GFP_KERNEL);
+
+	if (pmus) {
+		arm_pmu_acpi_determine_cpu_types(pmus);
+
+		for (j = 0; pmus[j].cpu_count; j++) {
+			pr_devel("CPU type %d, count %d\n", pmus[j].cpu_type,
+				 pmus[j].cpu_count);
+			res = kcalloc(pmus[j].cpu_count,
+				      sizeof(struct resource), GFP_KERNEL);
+
+			/* for a given PMU type collect all the GSIs. */
+			if (res) {
+				count = arm_pmu_acpi_gsi_res(&pmus[j], res,
+							     &last_cpu_id);
+				/*
+				 * register this set of interrupts
+				 * with a new PMU device
+				 */
+				err = arm_pmu_acpi_register_pmu(count,
+								res,
+								last_cpu_id);
+				kfree(res);
+			} else
+				pr_warn("PMU unable to allocate interrupt resource space\n");
+		}
+
+		kfree(pmus);
+	} else
+		pr_warn("PMU: Unable to allocate pmu count structures\n");
 
 	return err;
 }
+
 arch_initcall(pmu_acpi_init);
-- 
2.4.3

Re: [PATCH 0/6 v4] arm64/perf: Add ACPI support

[Jan Glauber]

Hi Jeremy,

I've tested the patches on ThunderX and got perf running with ACPI,
so you can add my Tested-by if you like.

Thanks,
Jan

On Tue, Apr 12, 2016 at 03:21:05PM -0500, Jeremy Linton wrote:
> v3->v4:
> Correct build issues with ARM (!ARM64) kernels.
> Add ThunderX to list of PMU types.
> 
> v3:
> Enable ARM performance monitoring units on ACPI/arm64 machines.
> 
> This patch expands and reworks the patches published by Mark Salter
> in order to clean up a few of the previous review comments, as well as
> add support for newer CPUs and big/little configurations.
> 
> I've been testing this patch in concert with an assortment of ACPI
> patches to enable things like PCIe. Its been tested on juno, seattle
> and some xgene systems.
> 
> Thanks,
> 
> *** BLURB HERE ***
> 
> Jeremy Linton (3):
>   arm: arm64: Add routine to determine cpuid of other cpus
>   arm64: pmu: Add ACPI support for A72 and ThunderX
>   arm64: pmu: Detect multiple PMU types in an ACPI system
> 
> Mark Salter (3):
>   arm: pmu: Fix non-devicetree probing
>   arm64: pmu: add fallback probe table
>   arm64: pmu: Add support for probing with ACPI
> 
>  arch/arm/include/asm/cputype.h   |   4 +
>  arch/arm64/include/asm/cputype.h |   4 +
>  arch/arm64/kernel/perf_event.c   |  12 ++-
>  arch/arm64/kernel/smp.c          |   5 +
>  drivers/perf/Kconfig             |   4 +
>  drivers/perf/Makefile            |   1 +
>  drivers/perf/arm_pmu.c           |  51 ++++++++--
>  drivers/perf/arm_pmu_acpi.c      | 213 +++++++++++++++++++++++++++++++++++++++
>  include/linux/perf/arm_pmu.h     |  10 ++
>  9 files changed, 293 insertions(+), 11 deletions(-)
>  create mode 100644 drivers/perf/arm_pmu_acpi.c
> 
> -- 
> 2.4.3