drivers/hwmon/coretemp.c: get TjMax value from MSR

The MSR IA32_TEMPERATURE_TARGET contains the TjMax value in the newer
Intel processors.

Signed-off-by: Huaxu Wan <huaxu.wan@linux.intel.com>
Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Yong Wang <yong.y.wang@linux.intel.com>
Cc: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index f9324851eba03971ec46e1a5a437bb041ba0088a..b49d8ca228f6ffe743e19d0423c676e62b1d29df 100644 (file)
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -236,6 +236,8 @@
 
 #define MSR_IA32_MISC_ENABLE           0x000001a0
 
+#define MSR_IA32_TEMPERATURE_TARGET    0x000001a2
+
 /* MISC_ENABLE bits: architectural */
 #define MSR_IA32_MISC_ENABLE_FAST_STRING       (1ULL << 0)
 #define MSR_IA32_MISC_ENABLE_TCC               (1ULL << 1)

diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 9fae7cbc5d768ac11863a17022ab335755080f46..2988da150ed6f7a223e64e892eed6d1ca2a18895 100644 (file)
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -241,6 +241,55 @@ static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *
        return tjmax;
 }
 
+static int __devinit get_tjmax(struct cpuinfo_x86 *c, u32 id,
+                              struct device *dev)
+{
+       /* The 100C is default for both mobile and non mobile CPUs */
+       int err;
+       u32 eax, edx;
+       u32 val;
+
+       /* 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);
+       if (err) {
+               dev_warn(dev, "Unable to read TjMax from CPU.\n");
+       } else {
+               val = (eax >> 16) & 0xff;
+               /*
+                * If the TjMax is not plausible, an assumption
+                * will be used
+                */
+               if ((val > 80) && (val < 120)) {
+                       dev_info(dev, "TjMax is %d C.\n", val);
+                       return val * 1000;
+               }
+       }
+
+       /*
+        * An assumption is made for early CPUs and unreadable MSR.
+        * NOTE: the given value may not be correct.
+        */
+
+       switch (c->x86_model) {
+       case 0xe:
+       case 0xf:
+       case 0x16:
+       case 0x1a:
+               dev_warn(dev, "TjMax is assumed as 100 C!\n");
+               return 100000;
+               break;
+       case 0x17:
+       case 0x1c:              /* Atom CPUs */
+               return adjust_tjmax(c, id, dev);
+               break;
+       default:
+               dev_warn(dev, "CPU (model=0x%x) is not supported yet,"
+                       " using default TjMax of 100C.\n", c->x86_model);
+               return 100000;
+       }
+}
+
 static int __devinit coretemp_probe(struct platform_device *pdev)
 {
        struct coretemp_data *data;
@@ -283,14 +332,18 @@ static int __devinit coretemp_probe(struct platform_device *pdev)
                }
        }
 
-       data->tjmax = adjust_tjmax(c, data->id, &pdev->dev);
+       data->tjmax = get_tjmax(c, data->id, &pdev->dev);
        platform_set_drvdata(pdev, data);
 
-       /* read the still undocumented IA32_TEMPERATURE_TARGET it exists
-          on older CPUs but not in this register, Atoms don't have it either */
+       /*
+        * read the still undocumented IA32_TEMPERATURE_TARGET. It exists
+        * on older CPUs but not in this register,
+        * Atoms don't have it either.
+        */
 
        if ((c->x86_model > 0xe) && (c->x86_model != 0x1c)) {
-               err = rdmsr_safe_on_cpu(data->id, 0x1a2, &eax, &edx);
+               err = rdmsr_safe_on_cpu(data->id, MSR_IA32_TEMPERATURE_TARGET,
+                   &eax, &edx);
                if (err) {
                        dev_warn(&pdev->dev, "Unable to read"
                                        " IA32_TEMPERATURE_TARGET MSR\n");