[PATCH V2 08/11] hwmon: (coretemp) Abstract core_temp helpers

From: Zhang Rui
Date: Fri Feb 02 2024 - 04:24:44 EST


coretemp driver has an obscure and fragile logic for handling package
and core temperature data.

Place the logic in newly introduced helpers for further optimizations.

No functional change.

Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
---
drivers/hwmon/coretemp.c | 118 +++++++++++++++++++++------------------
1 file changed, 64 insertions(+), 54 deletions(-)

diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 29ee8e0c0fe9..a19799a302a2 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -81,6 +81,7 @@ struct temp_data {
int tjmax;
unsigned long last_updated;
unsigned int cpu;
+ unsigned int index;
u32 cpu_core_id;
u32 status_reg;
int attr_size;
@@ -474,14 +475,36 @@ static struct platform_device *coretemp_get_pdev(unsigned int cpu)
return NULL;
}

-static struct temp_data *init_temp_data(unsigned int cpu, int pkg_flag)
+static struct temp_data *
+init_temp_data(struct platform_data *pdata, unsigned int cpu, int pkg_flag)
{
struct temp_data *tdata;
+ int index;

tdata = kzalloc(sizeof(struct temp_data), GFP_KERNEL);
if (!tdata)
return NULL;

+ /*
+ * Get the index of tdata in pdata->core_data[]
+ * tdata for package: pdata->core_data[1]
+ * tdata for core: pdata->core_data[2] .. pdata->core_data[NUM_REAL_CORES + 1]
+ */
+ if (pkg_flag) {
+ index = PKG_SYSFS_ATTR_NO;
+ } else {
+ index = ida_alloc_max(&pdata->ida, NUM_REAL_CORES - 1, GFP_KERNEL);
+ if (index < 0) {
+ kfree(tdata);
+ return NULL;
+ }
+ index += BASE_SYSFS_ATTR_NO;
+ }
+ /* Index in pdata->core_data[] */
+ tdata->index = index;
+
+ pdata->core_data[index] = tdata;
+
tdata->status_reg = pkg_flag ? MSR_IA32_PACKAGE_THERM_STATUS :
MSR_IA32_THERM_STATUS;
tdata->is_pkg_data = pkg_flag;
@@ -492,6 +515,30 @@ static struct temp_data *init_temp_data(unsigned int cpu, int pkg_flag)
return tdata;
}

+static void destroy_temp_data(struct platform_data *pdata, struct temp_data *tdata)
+{
+ pdata->core_data[tdata->index] = NULL;
+ if (!tdata->is_pkg_data)
+ ida_free(&pdata->ida, tdata->index - BASE_SYSFS_ATTR_NO);
+ kfree(tdata);
+}
+
+static struct temp_data *get_temp_data(struct platform_data *pdata, int cpu)
+{
+ int i;
+
+ /* cpu < 0 means get pkg temp_data */
+ if (cpu < 0)
+ return pdata->core_data[PKG_SYSFS_ATTR_NO];
+
+ for (i = BASE_SYSFS_ATTR_NO; i < MAX_CORE_DATA; i++) {
+ if (pdata->core_data[i] &&
+ pdata->core_data[i]->cpu_core_id == topology_core_id(cpu))
+ return pdata->core_data[i];
+ }
+ return NULL;
+}
+
static int create_core_data(struct platform_device *pdev, unsigned int cpu,
int pkg_flag)
{
@@ -499,36 +546,19 @@ static int create_core_data(struct platform_device *pdev, unsigned int cpu,
struct platform_data *pdata = platform_get_drvdata(pdev);
struct cpuinfo_x86 *c = &cpu_data(cpu);
u32 eax, edx;
- int err, index;
+ int err;

if (!housekeeping_cpu(cpu, HK_TYPE_MISC))
return 0;

- /*
- * Get the index of tdata in pdata->core_data[]
- * tdata for package: pdata->core_data[1]
- * tdata for core: pdata->core_data[2] .. pdata->core_data[NUM_REAL_CORES + 1]
- */
- if (pkg_flag) {
- index = PKG_SYSFS_ATTR_NO;
- } else {
- index = ida_alloc_max(&pdata->ida, NUM_REAL_CORES - 1, GFP_KERNEL);
- if (index < 0)
- return index;
-
- index += BASE_SYSFS_ATTR_NO;
- }
-
- tdata = init_temp_data(cpu, pkg_flag);
- if (!tdata) {
- err = -ENOMEM;
- goto ida_free;
- }
+ tdata = init_temp_data(pdata, cpu, pkg_flag);
+ if (!tdata)
+ return -ENOMEM;

/* Test if we can access the status register */
err = rdmsr_safe_on_cpu(cpu, tdata->status_reg, &eax, &edx);
if (err)
- goto exit_free;
+ goto err;

/* Make sure tdata->tjmax is a valid indicator for dynamic/static tjmax */
get_tjmax(tdata, &pdev->dev);
@@ -542,20 +572,15 @@ static int create_core_data(struct platform_device *pdev, unsigned int cpu,
if (get_ttarget(tdata, &pdev->dev) >= 0)
tdata->attr_size++;

- pdata->core_data[index] = tdata;
-
/* Create sysfs interfaces */
err = create_core_attrs(tdata, pdata->hwmon_dev);
if (err)
- goto exit_free;
+ goto err;

return 0;
-exit_free:
- pdata->core_data[index] = NULL;
- kfree(tdata);
-ida_free:
- if (!pkg_flag)
- ida_free(&pdata->ida, index - BASE_SYSFS_ATTR_NO);
+
+err:
+ destroy_temp_data(pdata, tdata);
return err;
}

@@ -566,10 +591,8 @@ coretemp_add_core(struct platform_device *pdev, unsigned int cpu, int pkg_flag)
dev_err(&pdev->dev, "Adding Core %u failed\n", cpu);
}

-static void coretemp_remove_core(struct platform_data *pdata, int indx)
+static void coretemp_remove_core(struct platform_data *pdata, struct temp_data *tdata)
{
- struct temp_data *tdata = pdata->core_data[indx];
-
/* if we errored on add then this is already gone */
if (!tdata)
return;
@@ -577,11 +600,7 @@ static void coretemp_remove_core(struct platform_data *pdata, int indx)
/* Remove the sysfs attributes */
sysfs_remove_group(&pdata->hwmon_dev->kobj, &tdata->attr_group);

- kfree(pdata->core_data[indx]);
- pdata->core_data[indx] = NULL;
-
- if (indx >= BASE_SYSFS_ATTR_NO)
- ida_free(&pdata->ida, indx - BASE_SYSFS_ATTR_NO);
+ destroy_temp_data(pdata, tdata);
}

static int coretemp_device_add(int zoneid)
@@ -694,7 +713,7 @@ static int coretemp_cpu_offline(unsigned int cpu)
struct platform_device *pdev = coretemp_get_pdev(cpu);
struct platform_data *pd;
struct temp_data *tdata;
- int i, target;
+ int target;

/* No need to tear down any interfaces for suspend */
if (cpuhp_tasks_frozen)
@@ -705,16 +724,7 @@ static int coretemp_cpu_offline(unsigned int cpu)
if (!pd->hwmon_dev)
return 0;

- for (i = BASE_SYSFS_ATTR_NO; i < MAX_CORE_DATA; i++) {
- if (pd->core_data[i] && pd->core_data[i]->cpu_core_id == topology_core_id(cpu))
- break;
- }
-
- /* Too many cores and this core is not populated, just return */
- if (i == MAX_CORE_DATA)
- return 0;
-
- tdata = pd->core_data[i];
+ tdata = get_temp_data(pd, cpu);

cpumask_clear_cpu(cpu, &pd->cpumask);

@@ -725,7 +735,7 @@ static int coretemp_cpu_offline(unsigned int cpu)
*/
target = cpumask_any_and(&pd->cpumask, topology_sibling_cpumask(cpu));
if (target >= nr_cpu_ids) {
- coretemp_remove_core(pd, i);
+ coretemp_remove_core(pd, tdata);
} else if (tdata && tdata->cpu == cpu) {
mutex_lock(&tdata->update_lock);
tdata->cpu = target;
@@ -735,10 +745,10 @@ static int coretemp_cpu_offline(unsigned int cpu)
/*
* If all cores in this pkg are offline, remove the interface.
*/
- tdata = pd->core_data[PKG_SYSFS_ATTR_NO];
+ tdata = get_temp_data(pd, -1);
if (cpumask_empty(&pd->cpumask)) {
if (tdata)
- coretemp_remove_core(pd, PKG_SYSFS_ATTR_NO);
+ coretemp_remove_core(pd, tdata);
hwmon_device_unregister(pd->hwmon_dev);
pd->hwmon_dev = NULL;
return 0;
--
2.34.1