[PATCH 2/2] hwmon: (coretemp) Get TjMax value from MSR
in [Kernel]
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From: Huaxu Wan on 7 May 2010 06:00 The MSR IA32_TEMPERATURE_TARGET contains the TjMax value in the newer processers. Signed-off-by: Huaxu Wan <huaxu.wan(a)linux.intel.com> --- drivers/hwmon/coretemp.c | 45 ++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 44 insertions(+), 1 deletions(-) diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c index 237c68d..7a01032 100644 --- a/drivers/hwmon/coretemp.c +++ b/drivers/hwmon/coretemp.c @@ -241,6 +241,49 @@ 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(0x1a2) contains the TjMax value */ + err = rdmsr_safe_on_cpu(id, 0x1a2, &eax, &edx); + if (err){ + printk_once(KERN_WARNING DRVNAME " : Unable to read TjMax from CPU.\n"); + } else { + val = (eax >> 16 ) & 0xff; + /* If the TjMax is not reasonable, an assumption value + will be used */ + if (( val > 80) && (val < 120)){ + printk_once(KERN_INFO DRVNAME " : The TjMax is %d C. \n", val); + return val * 1000; + } + } + + /* For the early CPUs, an approximation is given. + NOTE: the given value may not be correct. */ + switch(c->x86_model){ + case 0xe : + case 0xf : + case 0x16 : + case 0x1a : + printk_once(KERN_WARNING DRVNAME " : TjMax is assumed as 100 C! \n"); + return 100000; + break; + case 0x17 : + case 0x1c : /* Atom CPUs */ + return adjust_tjmax(c, id, dev); + break; + default : + printk_once(KERN_WARNING DRVNAME " : Your CPU is not support yet," + "using the default TjMax: 100 C.\n"); + return 100000; + } +} + static int __devinit coretemp_probe(struct platform_device *pdev) { struct coretemp_data *data; @@ -283,7 +326,7 @@ 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 -- 1.6.3.3.363.g725cf7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |