[PATCH 5/6] hwmon: amd_energy: dump energy counters via debugfs

[Naveen Krishna Chatradhi <nchatrad@amd.com>]

Use seq_printf to capture the core and socket energies under debugfs
path in '/sys/kernel/debug/amd_energy/'
file cenergy_dump: To print out the core energy counters
file senergy_dump: To print out the socket energy counters

Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com>
---
 drivers/hwmon/amd_energy.c | 110 +++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

diff --git a/drivers/hwmon/amd_energy.c b/drivers/hwmon/amd_energy.c
index c294bea56c02..2184bd4510ed 100644
--- a/drivers/hwmon/amd_energy.c
+++ b/drivers/hwmon/amd_energy.c
@@ -8,6 +8,7 @@
 #include <linux/bits.h>
 #include <linux/cpu.h>
 #include <linux/cpumask.h>
+#include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/hwmon.h>
@@ -20,6 +21,7 @@
 #include <linux/platform_device.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/smp.h>
 #include <linux/topology.h>
 #include <linux/types.h>
 
@@ -57,6 +59,8 @@ struct amd_energy_data {
 	int nr_socks;
 	int core_id;
 	char (*label)[10];
+	u64 *cdump;
+	u64 *sdump;
 };
 
 static int amd_energy_read_labels(struct device *dev,
@@ -329,6 +333,108 @@ static int create_accumulate_status_file(struct amd_energy_data *data)
 				 &accumulate_attr.attr);
 }
 
+#ifdef CONFIG_DEBUG_FS
+static void dump_on_each_cpu(void *info)
+{
+	struct amd_energy_data *data = info;
+	int cpu = smp_processor_id();
+
+	amd_add_delta(data, cpu, cpu, (long *)&data->cdump[cpu],
+		      ENERGY_CORE_MSR);
+}
+
+static int cenergy_dump_show(struct seq_file *s, void *unused)
+{
+	struct amd_energy_data *data = s->private;
+	struct cpumask *cpus_mask;
+	int i;
+
+	cpus_mask = kmalloc(sizeof(*cpus_mask), GFP_KERNEL);
+	memset(data->cdump, 0, (data->nr_cpus) * sizeof(u64));
+	cpumask_clear(cpus_mask);
+	for (i = 0; i < data->nr_cpus; i++) {
+		if (cpu_online(i))
+			cpumask_set_cpu(i, cpus_mask);
+	}
+
+	on_each_cpu_mask(cpus_mask, dump_on_each_cpu, data, true);
+
+	for (i = 0; i < data->nr_cpus; i++) {
+		if (!(i & 3))
+			seq_printf(s, "Core %3d: ", i);
+
+		seq_printf(s, "%16llu ", data->cdump[i]);
+		if ((i & 3) == 3)
+			seq_puts(s, "\n");
+	}
+	seq_puts(s, "\n");
+
+	kfree(cpus_mask);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(cenergy_dump);
+
+static int senergy_dump_show(struct seq_file *s, void *unused)
+{
+	struct amd_energy_data *data = s->private;
+	int i, cpu;
+
+	for (i = 0; i < data->nr_socks; i++) {
+		cpu = cpumask_first_and(cpu_online_mask,
+					cpumask_of_node(i));
+		amd_add_delta(data, data->nr_cpus + i, cpu,
+			      (long *)&data->sdump[i], ENERGY_PKG_MSR);
+		seq_printf(s, "Socket %1d: %16llu\n",
+			   i, data->sdump[i]);
+	}
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(senergy_dump);
+
+static void dump_debugfs_cleanup(void *ddir)
+{
+	debugfs_remove_recursive(ddir);
+}
+
+static int create_dump_file(struct device *dev,
+			    struct amd_energy_data *data)
+{
+	struct dentry *debugfs;
+	char name[] = "amd_energy";
+
+	data->cdump = devm_kcalloc(dev, data->nr_cpus,
+				   sizeof(u64), GFP_KERNEL);
+	if (!data->cdump)
+		return -ENOMEM;
+
+	data->sdump = devm_kcalloc(dev, data->nr_socks,
+				   sizeof(u64), GFP_KERNEL);
+	if (!data->sdump)
+		return -ENOMEM;
+
+	debugfs = debugfs_create_dir(name, NULL);
+	if (debugfs) {
+		debugfs_create_file("cenergy_dump", 0440,
+				    debugfs, data, &cenergy_dump_fops);
+		debugfs_create_file("senergy_dump", 0440,
+				    debugfs, data, &senergy_dump_fops);
+		devm_add_action_or_reset(data->hwmon_dev,
+					 dump_debugfs_cleanup, debugfs);
+	}
+
+	return 0;
+}
+#else
+
+static int create_dump_file(struct device *dev,
+			    struct amd_energy_data *data)
+{
+	return 0;
+}
+
+#endif //CONFIG_DEBUG_FS
+
 static int amd_energy_probe(struct platform_device *pdev)
 {
 	struct amd_energy_data *data;
@@ -376,6 +482,10 @@ static int amd_energy_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = create_dump_file(dev, data);
+	if (ret)
+		return ret;
+
 	return 0;
 }
 
-- 
2.26.2