Commit c0c67f87 authored by Zhang Rui's avatar Zhang Rui Committed by Guenter Roeck
Browse files

hwmon: (coretemp) Add support for dynamic tjmax 



Tjmax value retrieved from MSR_IA32_TEMPERATURE_TARGET can be changed at
runtime when the Intel SST-PP (Intel Speed Select Technology -
Performance Profile) level is changed.

Improve the code to always use updated tjmax when it can be retrieved
from MSR_IA32_TEMPERATURE_TARGET.

When tjmax can not be retrieved from MSR_IA32_TEMPERATURE_TARGET, still
follow the previous logic and always use a static tjmax value.

Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20221113153145.32696-3-rui.zhang@intel.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 2bc0e6d0

drivers/hwmon/coretemp.c

+31 −15
Original line number Diff line number Diff line
@@ -55,6 +55,8 @@ MODULE_PARM_DESC(tjmax, "TjMax value in degrees Celsius"); 


/*

 * Per-Core Temperature Data

 * @tjmax: The static tjmax value when tjmax cannot be retrieved from

 *		IA32_TEMPERATURE_TARGET MSR.

 * @last_updated: The time when the current temperature value was updated

 *		earlier (in jiffies).

 * @cpu_core_id: The CPU Core from which temperature values should be read
@@ -259,20 +261,25 @@ static bool cpu_has_tjmax(struct cpuinfo_x86 *c) 
	       model != 0x36;

}



static int get_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)

static int get_tjmax(struct temp_data *tdata, struct device *dev)

{

	struct cpuinfo_x86 *c = &cpu_data(tdata->cpu);

	int err;

	u32 eax, edx;

	u32 val;



	/* use static tjmax once it is set */

	if (tdata->tjmax)

		return tdata->tjmax;



	/*

	 * A new feature of current Intel(R) processors, the

	 * IA32_TEMPERATURE_TARGET contains the TjMax value

	 */

	err = rdmsr_safe_on_cpu(id, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);

	err = rdmsr_safe_on_cpu(tdata->cpu, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);

	if (err) {

		if (cpu_has_tjmax(c))

			dev_warn(dev, "Unable to read TjMax from CPU %u\n", id);

			dev_warn(dev, "Unable to read TjMax from CPU %u\n", tdata->cpu);

	} else {

		val = (eax >> 16) & 0xff;

		/*
@@ -288,14 +295,15 @@ static int get_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev) 
	if (force_tjmax) {

		dev_notice(dev, "TjMax forced to %d degrees C by user\n",

			   force_tjmax);

		return force_tjmax * 1000;

	}



		tdata->tjmax = force_tjmax * 1000;

	} else {

		/*

		 * An assumption is made for early CPUs and unreadable MSR.

		 * NOTE: the calculated value may not be correct.

		 */

	return adjust_tjmax(c, id, dev);

		tdata->tjmax = adjust_tjmax(c, tdata->cpu, dev);

	}

	return tdata->tjmax;

}



/* Keep track of how many zone pointers we allocated in init() */
@@ -336,8 +344,14 @@ static ssize_t show_tjmax(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];

	int tjmax;



	return sprintf(buf, "%d\n", pdata->core_data[attr->index]->tjmax);

	mutex_lock(&tdata->update_lock);

	tjmax = get_tjmax(tdata, dev);

	mutex_unlock(&tdata->update_lock);



	return sprintf(buf, "%d\n", tjmax);

}



static ssize_t show_ttarget(struct device *dev,
@@ -356,9 +370,11 @@ static ssize_t show_temp(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];

	int tjmax;



	mutex_lock(&tdata->update_lock);



	tjmax = get_tjmax(tdata, dev);

	/* Check whether the time interval has elapsed */

	if (time_after(jiffies, tdata->last_updated + HZ)) {

		rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
@@ -368,7 +384,7 @@ static ssize_t show_temp(struct device *dev, 
		 * Return it instead of reporting an error which doesn't

		 * really help at all.

		 */

		tdata->temp = tdata->tjmax - ((eax >> 16) & 0x7f) * 1000;

		tdata->temp = tjmax - ((eax >> 16) & 0x7f) * 1000;

		tdata->last_updated = jiffies;

	}
@@ -453,7 +469,7 @@ 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, index, attr_no;

	int err, index, attr_no, tjmax;



	/*

	 * Find attr number for sysfs:
@@ -488,7 +504,7 @@ static int create_core_data(struct platform_device *pdev, unsigned int cpu, 
		goto exit_free;



	/* We can access status register. Get Critical Temperature */

	tdata->tjmax = get_tjmax(c, cpu, &pdev->dev);

	tjmax = get_tjmax(tdata, &pdev->dev);



	/*

	 * Read the still undocumented bits 8:15 of IA32_TEMPERATURE_TARGET.
@@ -500,7 +516,7 @@ static int create_core_data(struct platform_device *pdev, unsigned int cpu, 
					&eax, &edx);

		if (!err) {

			tdata->ttarget

			  = tdata->tjmax - ((eax >> 8) & 0xff) * 1000;

			  = tjmax - ((eax >> 8) & 0xff) * 1000;

			tdata->attr_size++;

		}

	}