[PATCH 3/6] hwmon: amd_energy: Improve the accumulation logic

Naveen Krishna Chatradhi
2020-09-05T14:33:01Z

Factor out the common code in the accumulation functions for core and
socket accumulation.

While at it, handle the return value of the amd_create_sensor() function.

Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com>
---
drivers/hwmon/amd_energy.c | 126 +++++++++++++------------------------
1 file changed, 45 insertions(+), 81 deletions(-)

diff --git a/drivers/hwmon/amd_energy.c b/drivers/hwmon/amd_energy.c
index f0a13d6cc419..96c61784d05c 100644
--- a/drivers/hwmon/amd_energy.c
+++ b/drivers/hwmon/amd_energy.c
@@ -74,108 +74,67 @@ static void get_energy_units(struct amd_energy_data *data)
data->energy_units = (rapl_units & AMD_ENERGY_UNIT_MASK) >> 8;
}

-static void accumulate_socket_delta(struct amd_energy_data *data,
- int sock, int cpu)
+static void accumulate_delta(struct amd_energy_data *data,
+ int channel, int cpu, u32 reg)
{
- struct sensor_accumulator *s_accum;
+ struct sensor_accumulator *accum;
u64 input;

mutex_lock(&data->lock);
- rdmsrl_safe_on_cpu(cpu, ENERGY_PKG_MSR, &input);
+ rdmsrl_safe_on_cpu(cpu, reg, &input);
input &= AMD_ENERGY_MASK;

- s_accum = &data->accums[data->nr_cpus + sock];
- if (input >= s_accum->prev_value)
- s_accum->energy_ctr +=
- input - s_accum->prev_value;
+ accum = &data->accums[channel];
+ if (input >= accum->prev_value)
+ accum->energy_ctr +=
+ input - accum->prev_value;
else
- s_accum->energy_ctr += UINT_MAX -
- s_accum->prev_value + input;
+ accum->energy_ctr += UINT_MAX -
+ accum->prev_value + input;

- s_accum->prev_value = input;
+ accum->prev_value = input;
mutex_unlock(&data->lock);
}

-static void accumulate_core_delta(struct amd_energy_data *data)
+static void read_accumulate(struct amd_energy_data *data)
{
- struct sensor_accumulator *c_accum;
- u64 input;
- int cpu;
+ int sock, scpu, cpu;
+
+ for (sock = 0; sock < data->nr_socks; sock++) {
+ scpu = cpumask_first_and(cpu_online_mask,
+ cpumask_of_node(sock));
+
+ accumulate_delta(data, data->nr_cpus + sock,
+ scpu, ENERGY_PKG_MSR);
+ }

- mutex_lock(&data->lock);
if (data->core_id >= data->nr_cpus)
data->core_id = 0;

cpu = data->core_id;
+ if (cpu_online(cpu))
+ accumulate_delta(data, cpu, cpu, ENERGY_CORE_MSR);

- if (!cpu_online(cpu))
- goto out;
-
- rdmsrl_safe_on_cpu(cpu, ENERGY_CORE_MSR, &input);
- input &= AMD_ENERGY_MASK;
-
- c_accum = &data->accums[cpu];
-
- if (input >= c_accum->prev_value)
- c_accum->energy_ctr +=
- input - c_accum->prev_value;
- else
- c_accum->energy_ctr += UINT_MAX -
- c_accum->prev_value + input;
-
- c_accum->prev_value = input;
-
-out:
data->core_id++;
- mutex_unlock(&data->lock);
-}
-
-static void read_accumulate(struct amd_energy_data *data)
-{
- int sock;
-
- for (sock = 0; sock < data->nr_socks; sock++) {
- int cpu;
-
- cpu = cpumask_first_and(cpu_online_mask,
- cpumask_of_node(sock));
-
- accumulate_socket_delta(data, sock, cpu);
- }
-
- accumulate_core_delta(data);
}

static void amd_add_delta(struct amd_energy_data *data, int ch,
- int cpu, long *val, bool is_core)
+ int cpu, long *val, u32 reg)
{
- struct sensor_accumulator *s_accum, *c_accum;
+ struct sensor_accumulator *accum;
u64 input;

mutex_lock(&data->lock);
- if (!is_core) {
- rdmsrl_safe_on_cpu(cpu, ENERGY_PKG_MSR, &input);
- input &= AMD_ENERGY_MASK;
-
- s_accum = &data->accums[ch];
- if (input >= s_accum->prev_value)
- input += s_accum->energy_ctr -
- s_accum->prev_value;
- else
- input += UINT_MAX - s_accum->prev_value +
- s_accum->energy_ctr;
- } else {
- rdmsrl_safe_on_cpu(cpu, ENERGY_CORE_MSR, &input);
- input &= AMD_ENERGY_MASK;
+ rdmsrl_safe_on_cpu(cpu, reg, &input);
+ input &= AMD_ENERGY_MASK;

- c_accum = &data->accums[ch];
- if (input >= c_accum->prev_value)
- input += c_accum->energy_ctr -
- c_accum->prev_value;
- else
- input += UINT_MAX - c_accum->prev_value +
- c_accum->energy_ctr;
- }
+ accum = &data->accums[ch];
+ if (input >= accum->prev_value)
+ input += accum->energy_ctr -
+ accum->prev_value;
+ else
+ input += UINT_MAX - accum->prev_value +
+ accum->energy_ctr;

/* Energy consumed = (1/(2^ESU) * RAW * 1000000UL) μJoules */
*val = div64_ul(input * 1000000UL, BIT(data->energy_units));
@@ -188,20 +147,22 @@ static int amd_energy_read(struct device *dev,
u32 attr, int channel, long *val)
{
struct amd_energy_data *data = dev_get_drvdata(dev);
+ u32 reg;
int cpu;

if (channel >= data->nr_cpus) {
cpu = cpumask_first_and(cpu_online_mask,
cpumask_of_node
(channel - data->nr_cpus));
- amd_add_delta(data, channel, cpu, val, false);
+ reg = ENERGY_PKG_MSR;
} else {
cpu = channel;
if (!cpu_online(cpu))
return -ENODEV;

- amd_add_delta(data, channel, cpu, val, true);
+ reg = ENERGY_CORE_MSR;
}
+ amd_add_delta(data, channel, cpu, val, reg);

return 0;
}
@@ -249,7 +210,7 @@ static const struct hwmon_ops amd_energy_ops = {

static int amd_create_sensor(struct device *dev,
struct amd_energy_data *data,
- u8 type, u32 config)
+ enum hwmon_sensor_types type, u32 config)
{
struct hwmon_channel_info *info = &data->energy_info;
struct sensor_accumulator *accums;
@@ -308,6 +269,7 @@ static int amd_energy_probe(struct platform_device *pdev)
struct device *hwmon_dev;
struct amd_energy_data *data;
struct device *dev = &pdev->dev;
+ int ret;

data = devm_kzalloc(dev,
sizeof(struct amd_energy_data), GFP_KERNEL);
@@ -320,8 +282,10 @@ static int amd_energy_probe(struct platform_device *pdev)
dev_set_drvdata(dev, data);
/* Populate per-core energy reporting */
data->info[0] = &data->energy_info;
- amd_create_sensor(dev, data, hwmon_energy,
- HWMON_E_INPUT | HWMON_E_LABEL);
+ ret = amd_create_sensor(dev, data, hwmon_energy,
+ HWMON_E_INPUT | HWMON_E_LABEL);
+ if (ret)
+ return ret;

mutex_init(&data->lock);
get_energy_units(data);
@@ -346,7 +310,7 @@ static int amd_energy_probe(struct platform_device *pdev)
if (IS_ERR(data->wrap_accumulate))
return PTR_ERR(data->wrap_accumulate);

- return PTR_ERR_OR_ZERO(data->wrap_accumulate);
+ return 0;
}

static int amd_energy_remove(struct platform_device *pdev)
--
2.26.2