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Commit 7c96975c authored by Zhang Rui's avatar Zhang Rui Committed by Greg Kroah-Hartman
Browse files

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: default avatarZhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20240202092144.71180-3-rui.zhang@intel.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 1eb74c00

drivers/hwmon/coretemp.c

+19 −13
Original line number Diff line number Diff line
@@ -380,7 +380,7 @@ static int get_tjmax(struct cpuinfo_x86 *c, u32 id, 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,
@@ -392,13 +392,20 @@ 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;
@@ -456,23 +463,22 @@ 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;



	/*

	 * 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);
@@ -504,20 +510,20 @@ static int create_core_data(struct platform_device *pdev, unsigned int cpu, 
		}

	}



	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;

}