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Subject[PATCH 2/2] Get TjMax value from MSR
The MSR IA32_TEMPERATURE_TARGET contains the TjMax value in the newer
Intel processors.

CC: Andrew Morton <akpm@linux-foundation.org>
CC: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Huaxu Wan <huaxu.wan@linux.intel.com>
Signed-off-by: Carsten Emde <C.Emde@osadl.org>

---
arch/x86/include/asm/msr-index.h | 2 +
drivers/hwmon/coretemp.c | 61 ++++++++++++++++++++++++++++++++++++---
2 files changed, 59 insertions(+), 4 deletions(-)

Index: head/arch/x86/include/asm/msr-index.h
===================================================================
--- head.orig/arch/x86/include/asm/msr-index.h
+++ head/arch/x86/include/asm/msr-index.h
@@ -235,6 +235,8 @@

#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)
Index: head/drivers/hwmon/coretemp.c
===================================================================
--- head.orig/drivers/hwmon/coretemp.c
+++ head/drivers/hwmon/coretemp.c
@@ -241,6 +241,55 @@ static int __devinit adjust_tjmax(struct
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(stru
}
}

- 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");


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