hwmon: (coretemp) Add core/pkg threshold support to Coretemp

This patch adds the core and pkg support to coretemp.
These thresholds can be configured via the sysfs interfaces tempX_max
and tempX_max_hyst. An interrupt is generated when CPU temperature reaches
or crosses above tempX_max OR drops below tempX_max_hyst.

This patch is based on the documentation in IA Manual vol 3A, that can be
downloaded from here:
http://download.intel.com/design/processor/manuals/253668.pdf

Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

2 files changed, 139 insertions, 45 deletions

diff --git a/Documentation/hwmon/coretemp b/Documentation/hwmon/coretemp
index f85e913a3401..fa8776ab9b18 100644
--- a/Documentation/hwmon/coretemp
+++ b/Documentation/hwmon/coretemp
@@ -35,6 +35,13 @@ the Out-Of-Spec bit. Following table summarizes the exported sysfs files:
 All Sysfs entries are named with their core_id (represented here by 'X').
 tempX_input      - Core temperature (in millidegrees Celsius).
 tempX_max        - All cooling devices should be turned on (on Core2).
+                   Initialized with IA32_THERM_INTERRUPT. When the CPU
+                   temperature reaches this temperature, an interrupt is
+                   generated and tempX_max_alarm is set.
+tempX_max_hyst   - If the CPU temperature falls below than temperature,
+                   an interrupt is generated and tempX_max_alarm is reset.
+tempX_max_alarm  - Set if the temperature reaches or exceeds tempX_max.
+                   Reset if the temperature drops to or below tempX_max_hyst.
 tempX_crit       - Maximum junction temperature (in millidegrees Celsius).
 tempX_crit_alarm - Set when Out-of-spec bit is set, never clears.
                    Correct CPU operation is no longer guaranteed.
diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 0070d5476dd0..59d83e83da7f 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -44,7 +44,9 @@
 #define BASE_SYSFS_ATTR_NO      2       /* Sysfs Base attr no for coretemp */
 #define NUM_REAL_CORES          16      /* Number of Real cores per cpu */
 #define CORETEMP_NAME_LENGTH    17      /* String Length of attrs */
-#define MAX_ATTRS               5       /* Maximum no of per-core attrs */
+#define MAX_CORE_ATTRS          4       /* Maximum no of basic attrs */
+#define MAX_THRESH_ATTRS        3       /* Maximum no of Threshold attrs */
+#define TOTAL_ATTRS             (MAX_CORE_ATTRS + MAX_THRESH_ATTRS)
 #define MAX_CORE_DATA           (NUM_REAL_CORES + BASE_SYSFS_ATTR_NO)
 
 #ifdef CONFIG_SMP
@@ -67,6 +69,9 @@
  *              This value is passed as "id" field to rdmsr/wrmsr functions.
  * @status_reg: One of IA32_THERM_STATUS or IA32_PACKAGE_THERM_STATUS,
  *              from where the temperature values should be read.
+ * @intrpt_reg: One of IA32_THERM_INTERRUPT or IA32_PACKAGE_THERM_INTERRUPT,
+ *              from where the thresholds are read.
+ * @attr_size:  Total number of pre-core attrs displayed in the sysfs.
  * @is_pkg_data: If this is 1, the temp_data holds pkgtemp data.
  *              Otherwise, temp_data holds coretemp data.
  * @valid: If this is 1, the current temperature is valid.
@@ -74,15 +79,18 @@
 struct temp_data {
         int temp;
         int ttarget;
+        int tmin;
         int tjmax;
         unsigned long last_updated;
         unsigned int cpu;
         u32 cpu_core_id;
         u32 status_reg;
+        u32 intrpt_reg;
+        int attr_size;
         bool is_pkg_data;
         bool valid;
-        struct sensor_device_attribute sd_attrs[MAX_ATTRS];
-        char attr_name[MAX_ATTRS][CORETEMP_NAME_LENGTH];
+        struct sensor_device_attribute sd_attrs[TOTAL_ATTRS];
+        char attr_name[TOTAL_ATTRS][CORETEMP_NAME_LENGTH];
         struct mutex update_lock;
 };
 
@@ -135,6 +143,19 @@ static ssize_t show_crit_alarm(struct device *dev,
         return sprintf(buf, "%d\n", (eax >> 5) & 1);
 }
 
+static ssize_t show_max_alarm(struct device *dev,
+                                struct device_attribute *devattr, char *buf)
+{
+        u32 eax, edx;
+        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];
+
+        rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
+
+        return sprintf(buf, "%d\n", !!(eax & THERM_STATUS_THRESHOLD1));
+}
+
 static ssize_t show_tjmax(struct device *dev,
                         struct device_attribute *devattr, char *buf)
 {
@@ -153,6 +174,83 @@ static ssize_t show_ttarget(struct device *dev,
         return sprintf(buf, "%d\n", pdata->core_data[attr->index]->ttarget);
 }
 
+static ssize_t store_ttarget(struct device *dev,
+                                struct device_attribute *devattr,
+                                const char *buf, size_t count)
+{
+        struct platform_data *pdata = dev_get_drvdata(dev);
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct temp_data *tdata = pdata->core_data[attr->index];
+        u32 eax, edx;
+        unsigned long val;
+        int diff;
+
+        if (strict_strtoul(buf, 10, &val))
+                return -EINVAL;
+
+        /*
+         * THERM_MASK_THRESHOLD1 is 7 bits wide. Values are entered in terms
+         * of milli degree celsius. Hence don't accept val > (127 * 1000)
+         */
+        if (val > tdata->tjmax || val > 127000)
+                return -EINVAL;
+
+        diff = (tdata->tjmax - val) / 1000;
+
+        mutex_lock(&tdata->update_lock);
+        rdmsr_on_cpu(tdata->cpu, tdata->intrpt_reg, &eax, &edx);
+        eax = (eax & ~THERM_MASK_THRESHOLD1) |
+                                (diff << THERM_SHIFT_THRESHOLD1);
+        wrmsr_on_cpu(tdata->cpu, tdata->intrpt_reg, eax, edx);
+        tdata->ttarget = val;
+        mutex_unlock(&tdata->update_lock);
+
+        return count;
+}
+
+static ssize_t show_tmin(struct device *dev,
+                        struct device_attribute *devattr, char *buf)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct platform_data *pdata = dev_get_drvdata(dev);
+
+        return sprintf(buf, "%d\n", pdata->core_data[attr->index]->tmin);
+}
+
+static ssize_t store_tmin(struct device *dev,
+                                struct device_attribute *devattr,
+                                const char *buf, size_t count)
+{
+        struct platform_data *pdata = dev_get_drvdata(dev);
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct temp_data *tdata = pdata->core_data[attr->index];
+        u32 eax, edx;
+        unsigned long val;
+        int diff;
+
+        if (strict_strtoul(buf, 10, &val))
+                return -EINVAL;
+
+        /*
+         * THERM_MASK_THRESHOLD0 is 7 bits wide. Values are entered in terms
+         * of milli degree celsius. Hence don't accept val > (127 * 1000)
+         */
+        if (val > tdata->tjmax || val > 127000)
+                return -EINVAL;
+
+        diff = (tdata->tjmax - val) / 1000;
+
+        mutex_lock(&tdata->update_lock);
+        rdmsr_on_cpu(tdata->cpu, tdata->intrpt_reg, &eax, &edx);
+        eax = (eax & ~THERM_MASK_THRESHOLD0) |
+                                (diff << THERM_SHIFT_THRESHOLD0);
+        wrmsr_on_cpu(tdata->cpu, tdata->intrpt_reg, eax, edx);
+        tdata->tmin = val;
+        mutex_unlock(&tdata->update_lock);
+
+        return count;
+}
+
 static ssize_t show_temp(struct device *dev,
                         struct device_attribute *devattr, char *buf)
 {
@@ -344,23 +442,31 @@ static int create_core_attrs(struct temp_data *tdata, struct device *dev,
                                 int attr_no)
 {
         int err, i;
-        static ssize_t (*rd_ptr[MAX_ATTRS]) (struct device *dev,
+        static ssize_t (*rd_ptr[TOTAL_ATTRS]) (struct device *dev,
                         struct device_attribute *devattr, char *buf) = {
-                        show_label, show_crit_alarm, show_ttarget,
-                        show_temp, show_tjmax };
-        static const char *names[MAX_ATTRS] = {
+                        show_label, show_crit_alarm, show_temp, show_tjmax,
+                        show_max_alarm, show_ttarget, show_tmin };
+        static ssize_t (*rw_ptr[TOTAL_ATTRS]) (struct device *dev,
+                        struct device_attribute *devattr, const char *buf,
+                        size_t count) = { NULL, NULL, NULL, NULL, NULL,
+                                        store_ttarget, store_tmin };
+        static const char *names[TOTAL_ATTRS] = {
                                         "temp%d_label", "temp%d_crit_alarm",
-                                        "temp%d_max", "temp%d_input",
-                                        "temp%d_crit" };
+                                        "temp%d_input", "temp%d_crit",
+                                        "temp%d_max_alarm", "temp%d_max",
+                                        "temp%d_max_hyst" };
 
-        for (i = 0; i < MAX_ATTRS; i++) {
+        for (i = 0; i < tdata->attr_size; i++) {
                 snprintf(tdata->attr_name[i], CORETEMP_NAME_LENGTH, names[i],
                         attr_no);
                 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 = S_IRUGO;
+                if (rw_ptr[i]) {
+                        tdata->sd_attrs[i].dev_attr.attr.mode |= S_IWUSR;
+                        tdata->sd_attrs[i].dev_attr.store = rw_ptr[i];
+                }
                 tdata->sd_attrs[i].dev_attr.show = rd_ptr[i];
-                tdata->sd_attrs[i].dev_attr.store = NULL;
                 tdata->sd_attrs[i].index = attr_no;
                 err = device_create_file(dev, &tdata->sd_attrs[i].dev_attr);
                 if (err)
@@ -374,38 +480,6 @@ exit_free:
         return err;
 }
 
-static void update_ttarget(__u8 cpu_model, struct temp_data *tdata,
-                                struct device *dev)
-{
-        int err;
-        u32 eax, edx;
-
-        /*
-         * Initialize ttarget value. Eventually this will be
-         * initialized with the value from MSR_IA32_THERM_INTERRUPT
-         * register. If IA32_TEMPERATURE_TARGET is supported, this
-         * value will be over written below.
-         * To Do: Patch to initialize ttarget from MSR_IA32_THERM_INTERRUPT
-         */
-        tdata->ttarget = tdata->tjmax - 20000;
-
-        /*
-         * Read the still undocumented IA32_TEMPERATURE_TARGET. It exists
-         * on older CPUs but not in this register,
-         * Atoms don't have it either.
-         */
-        if (cpu_model > 0xe && cpu_model != 0x1c) {
-                err = rdmsr_safe_on_cpu(tdata->cpu,
-                                MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
-                if (err) {
-                        dev_warn(dev,
-                        "Unable to read IA32_TEMPERATURE_TARGET MSR\n");
-                } else {
-                        tdata->ttarget = tdata->tjmax -
-                                        ((eax >> 8) & 0xff) * 1000;
-                }
-        }
-}
 
 static int __devinit chk_ucode_version(struct platform_device *pdev)
 {
@@ -464,9 +538,12 @@ static struct temp_data *init_temp_data(unsigned int cpu, int pkg_flag)
 
         tdata->status_reg = pkg_flag ? MSR_IA32_PACKAGE_THERM_STATUS :
                                                         MSR_IA32_THERM_STATUS;
+        tdata->intrpt_reg = pkg_flag ? MSR_IA32_PACKAGE_THERM_INTERRUPT :
+                                                MSR_IA32_THERM_INTERRUPT;
         tdata->is_pkg_data = pkg_flag;
         tdata->cpu = cpu;
         tdata->cpu_core_id = TO_CORE_ID(cpu);
+        tdata->attr_size = MAX_CORE_ATTRS;
         mutex_init(&tdata->update_lock);
         return tdata;
 }
@@ -516,7 +593,17 @@ static int create_core_data(struct platform_data *pdata,
         else
                 tdata->tjmax = get_tjmax(c, cpu, &pdev->dev);
 
-        update_ttarget(c->x86_model, tdata, &pdev->dev);
+        /*
+         * Test if we can access the intrpt register. If so, increase the
+         * 'size' enough to have ttarget/tmin/max_alarm interfaces.
+         * Initialize ttarget with bits 16:22 of MSR_IA32_THERM_INTERRUPT
+         */
+        err = rdmsr_safe_on_cpu(cpu, tdata->intrpt_reg, &eax, &edx);
+        if (!err) {
+                tdata->attr_size += MAX_THRESH_ATTRS;
+                tdata->ttarget = tdata->tjmax - ((eax >> 16) & 0x7f) * 1000;
+        }
+
         pdata->core_data[attr_no] = tdata;
 
         /* Create sysfs interfaces */
@@ -553,7 +640,7 @@ static void coretemp_remove_core(struct platform_data *pdata,
         struct temp_data *tdata = pdata->core_data[indx];
 
         /* Remove the sysfs attributes */
-        for (i = 0; i < MAX_ATTRS; i++)
+        for (i = 0; i < tdata->attr_size; i++)
                 device_remove_file(dev, &tdata->sd_attrs[i].dev_attr);
 
         kfree(pdata->core_data[indx]);