powerpc/powernv: Detect and create IMC device

Code to create platform device for the In-Memory Collection (IMC)
counters. Platform devices are created based on the IMC compatibility.
New header file created to contain the data structures and macros
needed for In-Memory Collection (IMC) counter pmu devices.

The device tree for IMC counters starts at the node "imc-counters".
This node contains all the IMC PMU nodes and event nodes for these IMC
PMUs. Device probe() parses the device to locate three possible IMC
device types (Nest/Core/Thread). Function then branch to parse each
unit nodes to populate vital information such as device memory sizes,
event nodes information, base address for reserve memory access (if
any) and so on. Simple bare-minimum shutdown function added which only
"stops" the engines.

Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Signed-off-by: Hemant Kumar <hemant@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
[mpe: Fix build with CONFIG_PERF_EVENTS=n]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 128 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/imc-pmu.h b/arch/powerpc/include/asm/imc-pmu.h
new file mode 100644
index 000000000000..7f74c282710f
--- /dev/null
+++ b/arch/powerpc/include/asm/imc-pmu.h
@@ -0,0 +1,128 @@
+#ifndef __ASM_POWERPC_IMC_PMU_H
+#define __ASM_POWERPC_IMC_PMU_H
+
+/*
+ * IMC Nest Performance Monitor counter support.
+ *
+ * Copyright (C) 2017 Madhavan Srinivasan, IBM Corporation.
+ *           (C) 2017 Anju T Sudhakar, IBM Corporation.
+ *           (C) 2017 Hemant K Shaw, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or later version.
+ */
+
+#include <linux/perf_event.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/io.h>
+#include <asm/opal.h>
+
+/*
+ * For static allocation of some of the structures.
+ */
+#define IMC_MAX_PMUS			32
+
+/*
+ * Compatibility macros for IMC devices
+ */
+#define IMC_DTB_COMPAT			"ibm,opal-in-memory-counters"
+#define IMC_DTB_UNIT_COMPAT		"ibm,imc-counters"
+
+
+/*
+ * LDBAR: Counter address and Enable/Disable macro.
+ * perf/imc-pmu.c has the LDBAR layout information.
+ */
+#define THREAD_IMC_LDBAR_MASK           0x0003ffffffffe000ULL
+#define THREAD_IMC_ENABLE               0x8000000000000000ULL
+
+/*
+ * Structure to hold memory address information for imc units.
+ */
+struct imc_mem_info {
+	u64 *vbase;
+	u32 id;
+};
+
+/*
+ * Place holder for nest pmu events and values.
+ */
+struct imc_events {
+	u32 value;
+	char *name;
+	char *unit;
+	char *scale;
+};
+
+/* Event attribute array index */
+#define IMC_FORMAT_ATTR		0
+#define IMC_EVENT_ATTR		1
+#define IMC_CPUMASK_ATTR	2
+#define IMC_NULL_ATTR		3
+
+/* PMU Format attribute macros */
+#define IMC_EVENT_OFFSET_MASK	0xffffffffULL
+
+/*
+ * Device tree parser code detects IMC pmu support and
+ * registers new IMC pmus. This structure will hold the
+ * pmu functions, events, counter memory information
+ * and attrs for each imc pmu and will be referenced at
+ * the time of pmu registration.
+ */
+struct imc_pmu {
+	struct pmu pmu;
+	struct imc_mem_info *mem_info;
+	struct imc_events **events;
+	/*
+	 * Attribute groups for the PMU. Slot 0 used for
+	 * format attribute, slot 1 used for cpusmask attribute,
+	 * slot 2 used for event attribute. Slot 3 keep as
+	 * NULL.
+	 */
+	const struct attribute_group *attr_groups[4];
+	u32 counter_mem_size;
+	int domain;
+	/*
+	 * flag to notify whether the memory is mmaped
+	 * or allocated by kernel.
+	 */
+	bool imc_counter_mmaped;
+};
+
+/*
+ * Structure to hold id, lock and reference count for the imc events which
+ * are inited.
+ */
+struct imc_pmu_ref {
+	struct mutex lock;
+	unsigned int id;
+	int refc;
+};
+
+/*
+ * In-Memory Collection Counters type.
+ * Data comes from Device tree.
+ * Three device type are supported.
+ */
+
+enum {
+	IMC_TYPE_THREAD		= 0x1,
+	IMC_TYPE_CORE		= 0x4,
+	IMC_TYPE_CHIP           = 0x10,
+};
+
+/*
+ * Domains for IMC PMUs
+ */
+#define IMC_DOMAIN_NEST		1
+#define IMC_DOMAIN_CORE		2
+#define IMC_DOMAIN_THREAD	3
+
+extern int init_imc_pmu(struct device_node *parent,
+				struct imc_pmu *pmu_ptr, int pmu_id);
+extern void thread_imc_disable(void);
+#endif /* __ASM_POWERPC_IMC_PMU_H */