Re: [PATCH 2/3] hwmon: (coretemp) Remove unnecessary dependency of array index
From: Guenter Roeck
Date: Thu Nov 30 2023 - 22:26:39 EST
On 11/30/23 17:27, Ashok Raj wrote:
On Mon, Nov 27, 2023 at 09:16:50PM +0800, Zhang Rui wrote:
When sensor_device_attribute pointer is available, use container_of() to
get the temp_data address.
This removes the unnecessary dependency of cached index in
pdata->core_data[].
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
---
drivers/hwmon/coretemp.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 6053ed3761c2..cef43fedbd58 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -342,7 +342,7 @@ static ssize_t show_label(struct device *dev,
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct platform_data *pdata = dev_get_drvdata(dev);
- struct temp_data *tdata = pdata->core_data[attr->index];
+ struct temp_data *tdata = container_of(attr, struct temp_data, sd_attrs[ATTR_LABEL]);
if (tdata->is_pkg_data)
return sprintf(buf, "Package id %u\n", pdata->pkg_id);
@@ -355,8 +355,7 @@ static ssize_t show_crit_alarm(struct device *dev,
{
u32 eax, edx;
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
- struct platform_data *pdata = dev_get_drvdata(dev);
- struct temp_data *tdata = pdata->core_data[attr->index];
+ struct temp_data *tdata = container_of(attr, struct temp_data, sd_attrs[ATTR_CRIT_ALARM]);
mutex_lock(&tdata->update_lock);
rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
@@ -369,8 +368,7 @@ static ssize_t show_tjmax(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
- struct platform_data *pdata = dev_get_drvdata(dev);
- struct temp_data *tdata = pdata->core_data[attr->index];
+ struct temp_data *tdata = container_of(attr, struct temp_data, sd_attrs[ATTR_TJMAX]);
int tjmax;
mutex_lock(&tdata->update_lock);
@@ -384,8 +382,7 @@ static ssize_t show_ttarget(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
- struct platform_data *pdata = dev_get_drvdata(dev);
- struct temp_data *tdata = pdata->core_data[attr->index];
+ struct temp_data *tdata = container_of(attr, struct temp_data, sd_attrs[ATTR_TTARGET]);
int ttarget;
mutex_lock(&tdata->update_lock);
@@ -402,8 +399,7 @@ static ssize_t show_temp(struct device *dev,
{
u32 eax, edx;
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
- struct platform_data *pdata = dev_get_drvdata(dev);
- struct temp_data *tdata = pdata->core_data[attr->index];
+ struct temp_data *tdata = container_of(attr, struct temp_data, sd_attrs[ATTR_TEMP]);
int tjmax;
mutex_lock(&tdata->update_lock);
@@ -445,7 +441,6 @@ static int create_core_attrs(struct temp_data *tdata, struct device *dev,
tdata->sd_attrs[i].dev_attr.attr.name = tdata->attr_name[i];
tdata->sd_attrs[i].dev_attr.attr.mode = 0444;
tdata->sd_attrs[i].dev_attr.show = rd_ptr[i];
- tdata->sd_attrs[i].index = attr_no;
I was naively thinking if we could nuke that "index". I can see that used
in couple macros, but seems like we can lose it?
Completely untested.. and uncertain :-)
If you had suggested to replace
struct sensor_device_attribute sd_attrs[TOTAL_ATTRS];
with
struct device_attribute sd_attrs[TOTAL_ATTRS];
what you suggested may actually be possible and make sense. However,
suggesting to dump the index parameter of SENSOR_ATTR() completely
because _this_ driver may no longer need it seems to be a little excessive.
diff --git a/include/linux/hwmon-sysfs.h b/include/linux/hwmon-sysfs.h
index d896713359cd..4855893f9401 100644
--- a/include/linux/hwmon-sysfs.h
+++ b/include/linux/hwmon-sysfs.h
@@ -12,36 +12,35 @@
struct sensor_device_attribute{
struct device_attribute dev_attr;
- int index;
};
#define to_sensor_dev_attr(_dev_attr) \
container_of(_dev_attr, struct sensor_device_attribute, dev_attr)
-#define SENSOR_ATTR(_name, _mode, _show, _store, _index) \
+#define SENSOR_ATTR(_name, _mode, _show, _store) \
{ .dev_attr = __ATTR(_name, _mode, _show, _store), \
- .index = _index }
+ }
-#define SENSOR_ATTR_RO(_name, _func, _index) \
+#define SENSOR_ATTR_RO(_name, _func) \
SENSOR_ATTR(_name, 0444, _func##_show, NULL, _index)
-#define SENSOR_ATTR_RW(_name, _func, _index) \
- SENSOR_ATTR(_name, 0644, _func##_show, _func##_store, _index)
+#define SENSOR_ATTR_RW(_name, _func) \
+ SENSOR_ATTR(_name, 0644, _func##_show, _func##_store)
-#define SENSOR_ATTR_WO(_name, _func, _index) \
- SENSOR_ATTR(_name, 0200, NULL, _func##_store, _index)
+#define SENSOR_ATTR_WO(_name, _func) \
+ SENSOR_ATTR(_name, 0200, NULL, _func##_store)
-#define SENSOR_DEVICE_ATTR(_name, _mode, _show, _store, _index) \
+#define SENSOR_DEVICE_ATTR(_name, _mode, _show, _store) \
struct sensor_device_attribute sensor_dev_attr_##_name \
- = SENSOR_ATTR(_name, _mode, _show, _store, _index)
+ = SENSOR_ATTR(_name, _mode, _show, _store)
-#define SENSOR_DEVICE_ATTR_RO(_name, _func, _index) \
- SENSOR_DEVICE_ATTR(_name, 0444, _func##_show, NULL, _index)
+#define SENSOR_DEVICE_ATTR_RO(_name, _func) \
+ SENSOR_DEVICE_ATTR(_name, 0444, _func##_show, NULL)
#define SENSOR_DEVICE_ATTR_RW(_name, _func, _index) \
- SENSOR_DEVICE_ATTR(_name, 0644, _func##_show, _func##_store, _index)
+ SENSOR_DEVICE_ATTR(_name, 0644, _func##_show, _func##_store)
-#define SENSOR_DEVICE_ATTR_WO(_name, _func, _index) \
- SENSOR_DEVICE_ATTR(_name, 0200, NULL, _func##_store, _index)
+#define SENSOR_DEVICE_ATTR_WO(_name, _func) \
+ SENSOR_DEVICE_ATTR(_name, 0200, NULL, _func##_store)
struct sensor_device_attribute_2 {
struct device_attribute dev_attr;
diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
index 975da8e7f2a9..c3bbf2f7d6eb 100644
--- a/drivers/gpu/drm/i915/i915_hwmon.c
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -239,7 +239,7 @@ hwm_power1_max_interval_store(struct device *dev,
static SENSOR_DEVICE_ATTR(power1_max_interval, 0664,
hwm_power1_max_interval_show,
- hwm_power1_max_interval_store, 0);
+ hwm_power1_max_interval_store);
That driver could and should have used DEVICE_ATTR() instead of
SENSOR_DEVICE_ATTR(), and there are various other drivers where
that would have made sense. Actually, it should have used
DEVICE_ATTR_RW() but that is just a detail.
However, there are more than 2,000 uses of SENSOR_DEVICE_ATTR() and derived
macros in the kernel. The large majority of those do set index to values != 0,
and the affected drivers would not be happy if that argument disappeared.
Frankly, I am not entirely sure if you were serious with your suggestion.
I tried to give a serious reply, but I am not entirely sure if I succeeded.
My apologies if some sarcasm was bleeding through.
Guenter