[PATCH 3/7] hwmon/coretemp: Handle large core id value

Zhang Rui
2022-08-12T16:38:18Z

The coretemp driver supports up to a hard-coded limit of 128 cores.

Today, the driver can not support a core with an id above that limit.
Yet, the encoding of core_id's is arbitrary (BIOS APIC-id) and so they
may be sparse and they may be large.

Update the driver to map arbitrary core_id numbers into appropriate
array indexes so that 128 cores can be supported, no matter the encoding
of core_ids's.

Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
---
drivers/hwmon/coretemp.c | 55 +++++++++++++++++++++++++++++-----------
1 file changed, 40 insertions(+), 15 deletions(-)

diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index ccf0af5b988a..3f0f7d7612ae 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -46,9 +46,6 @@ MODULE_PARM_DESC(tjmax, "TjMax value in degrees Celsius");
#define TOTAL_ATTRS (MAX_CORE_ATTRS + 1)
#define MAX_CORE_DATA (NUM_REAL_CORES + BASE_SYSFS_ATTR_NO)

-#define TO_CORE_ID(cpu) (cpu_data(cpu).cpu_core_id)
-#define TO_ATTR_NO(cpu) (TO_CORE_ID(cpu) + BASE_SYSFS_ATTR_NO)
-
#ifdef CONFIG_SMP
#define for_each_sibling(i, cpu) \
for_each_cpu(i, topology_sibling_cpumask(cpu))
@@ -91,6 +88,8 @@ struct temp_data {
struct platform_data {
struct device *hwmon_dev;
u16 pkg_id;
+ u16 cpu_map[NUM_REAL_CORES];
+ struct ida ida;
struct cpumask cpumask;
struct temp_data *core_data[MAX_CORE_DATA];
struct device_attribute name_attr;
@@ -441,7 +440,7 @@ static struct temp_data *init_temp_data(unsigned int cpu, int pkg_flag)
MSR_IA32_THERM_STATUS;
tdata->is_pkg_data = pkg_flag;
tdata->cpu = cpu;
- tdata->cpu_core_id = TO_CORE_ID(cpu);
+ tdata->cpu_core_id = topology_core_id(cpu);
tdata->attr_size = MAX_CORE_ATTRS;
mutex_init(&tdata->update_lock);
return tdata;
@@ -454,7 +453,7 @@ 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, attr_no;
+ int err, index, attr_no;

/*
* Find attr number for sysfs:
@@ -462,14 +461,26 @@ static int create_core_data(struct platform_device *pdev, unsigned int cpu,
* The attr number is always core id + 2
* The Pkgtemp will always show up as temp1_*, if available
*/
- attr_no = pkg_flag ? PKG_SYSFS_ATTR_NO : TO_ATTR_NO(cpu);
+ if (pkg_flag)
+ attr_no = PKG_SYSFS_ATTR_NO;
+ else {
+ index = ida_alloc(&pdata->ida, GFP_KERNEL);
+ if (index < 0)
+ return index;
+ pdata->cpu_map[index] = topology_core_id(cpu);
+ attr_no = index + BASE_SYSFS_ATTR_NO;
+ }

- if (attr_no > MAX_CORE_DATA - 1)
- return -ERANGE;
+ if (attr_no > MAX_CORE_DATA - 1) {
+ err = -ERANGE;
+ goto ida_free;
+ }

tdata = init_temp_data(cpu, pkg_flag);
- if (!tdata)
- return -ENOMEM;
+ if (!tdata) {
+ err = -ENOMEM;
+ goto ida_free;
+ }

/* Test if we can access the status register */
err = rdmsr_safe_on_cpu(cpu, tdata->status_reg, &eax, &edx);
@@ -505,6 +516,9 @@ static int create_core_data(struct platform_device *pdev, unsigned int cpu,
exit_free:
pdata->core_data[attr_no] = NULL;
kfree(tdata);
+ida_free:
+ if (!pkg_flag)
+ ida_free(&pdata->ida, index);
return err;
}

@@ -524,6 +538,8 @@ static void coretemp_remove_core(struct platform_data *pdata, int indx)

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

static int coretemp_probe(struct platform_device *pdev)
@@ -537,6 +553,7 @@ static int coretemp_probe(struct platform_device *pdev)
return -ENOMEM;

pdata->pkg_id = pdev->id;
+ ida_init(&pdata->ida);
platform_set_drvdata(pdev, pdata);

pdata->hwmon_dev = devm_hwmon_device_register_with_groups(dev, DRVNAME,
@@ -553,6 +570,7 @@ static int coretemp_remove(struct platform_device *pdev)
if (pdata->core_data[i])
coretemp_remove_core(pdata, i);

+ ida_destroy(&pdata->ida);
return 0;
}

@@ -647,7 +665,7 @@ 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 indx, target;
+ int i, indx = -1, target;

/*
* Don't execute this on suspend as the device remove locks
@@ -660,12 +678,19 @@ static int coretemp_cpu_offline(unsigned int cpu)
if (!pdev)
return 0;

- /* The core id is too big, just return */
- indx = TO_ATTR_NO(cpu);
- if (indx > MAX_CORE_DATA - 1)
+ pd = platform_get_drvdata(pdev);
+
+ for (i = 0; i < NUM_REAL_CORES; i++) {
+ if (pd->cpu_map[i] == topology_core_id(cpu)) {
+ indx = i + BASE_SYSFS_ATTR_NO;
+ break;
+ }
+ }
+
+ /* Too many cores and this core is not pupolated, just return */
+ if (indx < 0)
return 0;

- pd = platform_get_drvdata(pdev);
tdata = pd->core_data[indx];

cpumask_clear_cpu(cpu, &pd->cpumask);
--
2.34.1