hwmon: (coretemp) Fix bogus core_id to attr name mapping

[ Upstream commit fdaf0c8629d4524a168cb9e4ad4231875749b28c ]

Before commit 7108b80a542b ("hwmon/coretemp: Handle large core ID
value"), there is a fixed mapping between
1. cpu_core_id
2. the index in pdata->core_data[] array
3. the sysfs attr name, aka "tempX_"
The later two always equal cpu_core_id + 2.

After the commit, pdata->core_data[] index is got from ida so that it
can handle sparse core ids and support more cores within a package.

However, the commit erroneously maps the sysfs attr name to
pdata->core_data[] index instead of cpu_core_id + 2.

As a result, the code is not aligned with the comments, and brings user
visible changes in hwmon sysfs on systems with sparse core id.

For example, before commit 7108b80a542b ("hwmon/coretemp: Handle large
core ID value"),
/sys/class/hwmon/hwmon2/temp2_label:Core 0
/sys/class/hwmon/hwmon2/temp3_label:Core 1
/sys/class/hwmon/hwmon2/temp4_label:Core 2
/sys/class/hwmon/hwmon2/temp5_label:Core 3
/sys/class/hwmon/hwmon2/temp6_label:Core 4
/sys/class/hwmon/hwmon3/temp10_label:Core 8
/sys/class/hwmon/hwmon3/temp11_label:Core 9
after commit,
/sys/class/hwmon/hwmon2/temp2_label:Core 0
/sys/class/hwmon/hwmon2/temp3_label:Core 1
/sys/class/hwmon/hwmon2/temp4_label:Core 2
/sys/class/hwmon/hwmon2/temp5_label:Core 3
/sys/class/hwmon/hwmon2/temp6_label:Core 4
/sys/class/hwmon/hwmon2/temp7_label:Core 8
/sys/class/hwmon/hwmon2/temp8_label:Core 9

Restore the previous behavior and rework the code, comments and variable
names to avoid future confusions.

Fixes: 7108b80a542b ("hwmon/coretemp: Handle large core ID value")
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20240202092144.71180-3-rui.zhang@intel.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index e78c769..95f4c0b 100644 (file)
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -419,7 +419,7 @@ static ssize_t show_temp(struct device *dev,
 }
 
 static int create_core_attrs(struct temp_data *tdata, struct device *dev,
-                            int attr_no)
+                            int index)
 {
        int i;
        static ssize_t (*const rd_ptr[TOTAL_ATTRS]) (struct device *dev,
@@ -431,13 +431,20 @@ static int create_core_attrs(struct temp_data *tdata, struct device *dev,
        };
 
        for (i = 0; i < tdata->attr_size; i++) {
+               /*
+                * We map the attr number to core id of the CPU
+                * The attr number is always core id + 2
+                * The Pkgtemp will always show up as temp1_*, if available
+                */
+               int attr_no = tdata->is_pkg_data ? 1 : tdata->cpu_core_id + 2;
+
                snprintf(tdata->attr_name[i], CORETEMP_NAME_LENGTH,
                         "temp%d_%s", attr_no, suffixes[i]);
                sysfs_attr_init(&tdata->sd_attrs[i].dev_attr.attr);
                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;
+               tdata->sd_attrs[i].index = index;
                tdata->attrs[i] = &tdata->sd_attrs[i].dev_attr.attr;
        }
        tdata->attr_group.attrs = tdata->attrs;
@@ -495,26 +502,25 @@ 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, attr_no;
+       int err, index;
 
        if (!housekeeping_cpu(cpu, HK_TYPE_MISC))
                return 0;
 
        /*
-        * Find attr number for sysfs:
-        * We map the attr number to core id of the CPU
-        * The attr number is always core id + 2
-        * The Pkgtemp will always show up as temp1_*, if available
+        * 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) {
-               attr_no = PKG_SYSFS_ATTR_NO;
+               index = PKG_SYSFS_ATTR_NO;
        } else {
                index = ida_alloc_max(&pdata->ida, NUM_REAL_CORES - 1, GFP_KERNEL);
                if (index < 0)
                        return index;
 
                pdata->cpu_map[index] = topology_core_id(cpu);
-               attr_no = index + BASE_SYSFS_ATTR_NO;
+               index += BASE_SYSFS_ATTR_NO;
        }
 
        tdata = init_temp_data(cpu, pkg_flag);
@@ -540,20 +546,20 @@ 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[attr_no] = tdata;
+       pdata->core_data[index] = tdata;
 
        /* Create sysfs interfaces */
-       err = create_core_attrs(tdata, pdata->hwmon_dev, attr_no);
+       err = create_core_attrs(tdata, pdata->hwmon_dev, index);
        if (err)
                goto exit_free;
 
        return 0;
 exit_free:
-       pdata->core_data[attr_no] = NULL;
+       pdata->core_data[index] = NULL;
        kfree(tdata);
 ida_free:
        if (!pkg_flag)
-               ida_free(&pdata->ida, index);
+               ida_free(&pdata->ida, index - BASE_SYSFS_ATTR_NO);
        return err;
 }