Since, the IMC counters' data are periodically fed to a memory location,
the functions to read/update, start/stop, add/del can be generic and can
be used by all IMC PMU units.

This patch adds a set of generic imc pmu related event functions to be
used  by each imc pmu unit. Add code to setup format attribute and to
register imc pmus. Add a event_init function for nest_imc events.

Cc: Madhavan Srinivasan <ma...@linux.vnet.ibm.com>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Anton Blanchard <an...@samba.org>
Cc: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com>
Cc: Michael Neuling <mi...@neuling.org>
Cc: Stewart Smith <stew...@linux.vnet.ibm.com>
Cc: Daniel Axtens <d...@axtens.net>
Cc: Stephane Eranian <eran...@google.com>
Signed-off-by: Hemant Kumar <hem...@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/imc-pmu.h        |   1 +
 arch/powerpc/perf/imc-pmu.c               | 122 ++++++++++++++++++++++++++++++
 arch/powerpc/platforms/powernv/opal-imc.c |  29 ++++++-
 3 files changed, 148 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/imc-pmu.h 
b/arch/powerpc/include/asm/imc-pmu.h
index 911d837..ceb6b1f 100644
--- a/arch/powerpc/include/asm/imc-pmu.h
+++ b/arch/powerpc/include/asm/imc-pmu.h
@@ -70,4 +70,5 @@ struct imc_pmu {
 
 #define UNKNOWN_DOMAIN         -1
 
+int imc_get_domain(struct device_node *pmu_dev);
 #endif /* PPC_POWERNV_IMC_PMU_DEF_H */
diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
index 7b6ce50..f12ece8 100644
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -17,6 +17,117 @@
 struct perchip_nest_info nest_perchip_info[IMC_MAX_CHIPS];
 struct imc_pmu *per_nest_pmu_arr[IMC_MAX_PMUS];
 
+/* Needed for sanity check */
+extern u64 nest_max_offset;
+
+PMU_FORMAT_ATTR(event, "config:0-20");
+static struct attribute *imc_format_attrs[] = {
+       &format_attr_event.attr,
+       NULL,
+};
+
+static struct attribute_group imc_format_group = {
+       .name = "format",
+       .attrs = imc_format_attrs,
+};
+
+static int nest_imc_event_init(struct perf_event *event)
+{
+       int chip_id;
+       u32 config = event->attr.config;
+       struct perchip_nest_info *pcni;
+
+       if (event->attr.type != event->pmu->type)
+               return -ENOENT;
+
+       /* Sampling not supported */
+       if (event->hw.sample_period)
+               return -EINVAL;
+
+       /* unsupported modes and filters */
+       if (event->attr.exclude_user   ||
+           event->attr.exclude_kernel ||
+           event->attr.exclude_hv     ||
+           event->attr.exclude_idle   ||
+           event->attr.exclude_host   ||
+           event->attr.exclude_guest)
+               return -EINVAL;
+
+       if (event->cpu < 0)
+               return -EINVAL;
+
+       /* Sanity check for config (event offset) */
+       if (config > nest_max_offset)
+               return -EINVAL;
+
+       chip_id = topology_physical_package_id(event->cpu);
+       pcni = &nest_perchip_info[chip_id];
+       event->hw.event_base = pcni->vbase[config/PAGE_SIZE] +
+                                                       (config & ~PAGE_MASK);
+
+       return 0;
+}
+
+static void imc_read_counter(struct perf_event *event)
+{
+       u64 *addr, data;
+
+       addr = (u64 *)event->hw.event_base;
+       data = __be64_to_cpu(*addr);
+       local64_set(&event->hw.prev_count, data);
+}
+
+static void imc_perf_event_update(struct perf_event *event)
+{
+       u64 counter_prev, counter_new, final_count, *addr;
+
+       addr = (u64 *)event->hw.event_base;
+       counter_prev = local64_read(&event->hw.prev_count);
+       counter_new = __be64_to_cpu(*addr);
+       final_count = counter_new - counter_prev;
+
+       local64_set(&event->hw.prev_count, counter_new);
+       local64_add(final_count, &event->count);
+}
+
+static void imc_event_start(struct perf_event *event, int flags)
+{
+       imc_read_counter(event);
+}
+
+static void imc_event_stop(struct perf_event *event, int flags)
+{
+       if (flags & PERF_EF_UPDATE)
+               imc_perf_event_update(event);
+}
+
+static int imc_event_add(struct perf_event *event, int flags)
+{
+       if (flags & PERF_EF_START)
+               imc_event_start(event, flags);
+
+       return 0;
+}
+
+/* update_pmu_ops : Populate the appropriate operations for "pmu" */
+static int update_pmu_ops(struct imc_pmu *pmu)
+{
+       if (!pmu)
+               return -EINVAL;
+
+       pmu->pmu.task_ctx_nr = perf_invalid_context;
+       pmu->pmu.event_init = nest_imc_event_init;
+       pmu->pmu.add = imc_event_add;
+       pmu->pmu.del = imc_event_stop;
+       pmu->pmu.start = imc_event_start;
+       pmu->pmu.stop = imc_event_stop;
+       pmu->pmu.read = imc_perf_event_update;
+       pmu->attr_groups[1] = &imc_format_group;
+       pmu->pmu.attr_groups = pmu->attr_groups;
+
+       return 0;
+}
+
 /* dev_str_attr : Populate event "name" and string "str" in attribute */
 static struct attribute *dev_str_attr(const char *name, const char *str)
 {
@@ -83,6 +194,17 @@ int init_imc_pmu(struct imc_events *events, int idx,
        if (ret)
                goto err_free;
 
+       ret = update_pmu_ops(pmu_ptr);
+       if (ret)
+               goto err_free;
+
+       ret = perf_pmu_register(&pmu_ptr->pmu, pmu_ptr->pmu.name, -1);
+       if (ret)
+               goto err_free;
+
+       pr_info("%s performance monitor hardware support registered\n",
+               pmu_ptr->pmu.name);
+
        return 0;
 
 err_free:
diff --git a/arch/powerpc/platforms/powernv/opal-imc.c 
b/arch/powerpc/platforms/powernv/opal-imc.c
index 7870401..a2ca8e4 100644
--- a/arch/powerpc/platforms/powernv/opal-imc.c
+++ b/arch/powerpc/platforms/powernv/opal-imc.c
@@ -36,6 +36,7 @@ extern struct imc_pmu *per_nest_pmu_arr[IMC_MAX_PMUS];
 
 extern int init_imc_pmu(struct imc_events *events,
                        int idx, struct imc_pmu *pmu_ptr);
+u64 nest_max_offset;
 
 static int imc_event_info(char *name, struct imc_events *events)
 {
@@ -68,8 +69,25 @@ static int imc_event_info_str(struct property *pp, char 
*name,
        return 0;
 }
 
+/*
+ * Updates the maximum offset for an event in the pmu with domain
+ * "pmu_domain". Right now, only nest domain is supported.
+ */
+static void update_max_value(u32 value, int pmu_domain)
+{
+       switch (pmu_domain) {
+       case IMC_DOMAIN_NEST:
+               if (nest_max_offset < value)
+                       nest_max_offset = value;
+               break;
+       default:
+               /* Unknown domain, return */
+               return;
+       }
+}
+
 static int imc_event_info_val(char *name, u32 val,
-                             struct imc_events *events)
+                             struct imc_events *events, int pmu_domain)
 {
        int ret;
 
@@ -77,6 +95,7 @@ static int imc_event_info_val(char *name, u32 val,
        if (ret)
                return ret;
        sprintf(events->ev_value, "event=0x%x", val);
+       update_max_value(val, pmu_domain);
 
        return 0;
 }
@@ -111,7 +130,8 @@ static int set_event_property(struct property *pp, char 
*event_prop,
 static int imc_events_node_parser(struct device_node *dev,
                                  struct imc_events *events,
                                  struct property *event_scale,
-                                 struct property *event_unit)
+                                 struct property *event_unit,
+                                 int pmu_domain)
 {
        struct property *name, *pp;
        char *ev_name;
@@ -153,7 +173,8 @@ static int imc_events_node_parser(struct device_node *dev,
                 */
                if (strncmp(pp->name, "reg", 3) == 0) {
                        of_property_read_u32(dev, pp->name, &val);
-                       ret = imc_event_info_val(ev_name, val, &events[idx]);
+                       ret = imc_event_info_val(ev_name, val, &events[idx],
+                               pmu_domain);
                        if (ret) {
                                kfree(events[idx].ev_name);
                                kfree(events[idx].ev_value);
@@ -322,7 +343,7 @@ static int imc_pmu_create(struct device_node *parent, int 
pmu_index)
        /* Loop through event nodes */
        for_each_child_of_node(parent, ev_node) {
                ret = imc_events_node_parser(ev_node, &events[idx], scale_pp,
-                                            unit_pp);
+                                            unit_pp, pmu_ptr->domain);
                if (ret < 0) {
                        /* Unable to parse this event */
                        if (ret == -ENOMEM)
-- 
2.7.4

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