From 89a3fd35ba0318a7208e2c8d8ca6189f567d4a93 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 13 Sep 2010 10:05:51 +0000 Subject: x86/hwmon: fix module init for hotplug-but-no-device-found case In commit 0dca94baeab4a1a514841b0a4c8e3a51dfb4d5ae the call to platform_driver_unregister() was made conditional upon !HOTPLUG_CPU, but the return value from coretemp_init() was left to indicate an error. This isn't correct, as the negative return value indicates to the module loader that initialization failed, which isn't intended here and results in dangling pointers. Signed-off-by: Jan Beulich Cc: Chen Gong Signed-off-by: Guenter Roeck --- drivers/hwmon/coretemp.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/hwmon/coretemp.c') diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c index de8111114f4..6b3ef553bd1 100644 --- a/drivers/hwmon/coretemp.c +++ b/drivers/hwmon/coretemp.c @@ -541,16 +541,19 @@ static int __init coretemp_init(void) " has no thermal sensor.\n", c->x86_model); } } + +#ifndef CONFIG_HOTPLUG_CPU if (list_empty(&pdev_list)) { err = -ENODEV; goto exit_driver_unreg; } +#endif register_hotcpu_notifier(&coretemp_cpu_notifier); return 0; -exit_driver_unreg: #ifndef CONFIG_HOTPLUG_CPU +exit_driver_unreg: platform_driver_unregister(&coretemp_driver); #endif exit: -- cgit v1.2.3-70-g09d2 From a46590533ad7b0f3f640732081d7e1658145c0ba Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 23 Sep 2010 22:21:34 -0700 Subject: x86/hwmon: fix initialization of coretemp Using cpuid_eax() to determine feature availability on other than the current CPU is invalid. And feature availability should also be checked in the hotplug code path. Signed-off-by: Jan Beulich Cc: Rudolf Marek Cc: Fenghua Yu Signed-off-by: Guenter Roeck --- arch/x86/include/asm/cpufeature.h | 1 + arch/x86/kernel/cpu/scattered.c | 1 + drivers/hwmon/coretemp.c | 29 +++++++++++++---------------- 3 files changed, 15 insertions(+), 16 deletions(-) (limited to 'drivers/hwmon/coretemp.c') diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index c6fbb7b430d..3f76523589a 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -168,6 +168,7 @@ #define X86_FEATURE_XSAVEOPT (7*32+ 4) /* Optimized Xsave */ #define X86_FEATURE_PLN (7*32+ 5) /* Intel Power Limit Notification */ #define X86_FEATURE_PTS (7*32+ 6) /* Intel Package Thermal Status */ +#define X86_FEATURE_DTS (7*32+ 7) /* Digital Thermal Sensor */ /* Virtualization flags: Linux defined, word 8 */ #define X86_FEATURE_TPR_SHADOW (8*32+ 0) /* Intel TPR Shadow */ diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index 34b4dad6f0b..d4907951512 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -31,6 +31,7 @@ void __cpuinit init_scattered_cpuid_features(struct cpuinfo_x86 *c) const struct cpuid_bit *cb; static const struct cpuid_bit __cpuinitconst cpuid_bits[] = { + { X86_FEATURE_DTS, CR_EAX, 0, 0x00000006, 0 }, { X86_FEATURE_IDA, CR_EAX, 1, 0x00000006, 0 }, { X86_FEATURE_ARAT, CR_EAX, 2, 0x00000006, 0 }, { X86_FEATURE_PLN, CR_EAX, 4, 0x00000006, 0 }, diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c index 6b3ef553bd1..5850da64ae2 100644 --- a/drivers/hwmon/coretemp.c +++ b/drivers/hwmon/coretemp.c @@ -423,9 +423,18 @@ static int __cpuinit coretemp_device_add(unsigned int cpu) int err; struct platform_device *pdev; struct pdev_entry *pdev_entry; -#ifdef CONFIG_SMP struct cpuinfo_x86 *c = &cpu_data(cpu); -#endif + + /* + * CPUID.06H.EAX[0] indicates whether the CPU has thermal + * sensors. We check this bit only, all the early CPUs + * without thermal sensors will be filtered out. + */ + if (!cpu_has(c, X86_FEATURE_DTS)) { + printk(KERN_INFO DRVNAME ": CPU (model=0x%x)" + " has no thermal sensor.\n", c->x86_model); + return 0; + } mutex_lock(&pdev_list_mutex); @@ -527,20 +536,8 @@ static int __init coretemp_init(void) if (err) goto exit; - for_each_online_cpu(i) { - struct cpuinfo_x86 *c = &cpu_data(i); - /* - * CPUID.06H.EAX[0] indicates whether the CPU has thermal - * sensors. We check this bit only, all the early CPUs - * without thermal sensors will be filtered out. - */ - if (c->cpuid_level >= 6 && (cpuid_eax(0x06) & 0x01)) - coretemp_device_add(i); - else { - printk(KERN_INFO DRVNAME ": CPU (model=0x%x)" - " has no thermal sensor.\n", c->x86_model); - } - } + for_each_online_cpu(i) + coretemp_device_add(i); #ifndef CONFIG_HOTPLUG_CPU if (list_empty(&pdev_list)) { -- cgit v1.2.3-70-g09d2 From e40cc4bdfd4b89813f072f72bd9c7055814d3f0f Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 13 Sep 2010 10:23:05 +0000 Subject: x86/hwmon: register alternate sibling upon CPU removal Just like pkgtemp registers another core of the same package when one gets removed, coretemp should register another hyperthread (if available) in that situation. As pointed out in the patch fixing the respective code in pkgtemp, the list protectng mutex must be dropped before calling coretemp_device_add(), and due to the restructured loop (including an explicit return) the "safe" variant of the list iterator isn't needed anymore. Signed-off-by: Jan Beulich Cc: Rudolf Marek Signed-off-by: Guenter Roeck --- drivers/hwmon/coretemp.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) (limited to 'drivers/hwmon/coretemp.c') diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c index 5850da64ae2..baa842a80b4 100644 --- a/drivers/hwmon/coretemp.c +++ b/drivers/hwmon/coretemp.c @@ -491,14 +491,22 @@ exit: static void coretemp_device_remove(unsigned int cpu) { - struct pdev_entry *p, *n; + struct pdev_entry *p; + unsigned int i; + mutex_lock(&pdev_list_mutex); - list_for_each_entry_safe(p, n, &pdev_list, list) { - if (p->cpu == cpu) { - platform_device_unregister(p->pdev); - list_del(&p->list); - kfree(p); - } + list_for_each_entry(p, &pdev_list, list) { + if (p->cpu != cpu) + continue; + + platform_device_unregister(p->pdev); + list_del(&p->list); + mutex_unlock(&pdev_list_mutex); + kfree(p); + for_each_cpu(i, cpu_sibling_mask(cpu)) + if (i != cpu && !coretemp_device_add(i)) + break; + return; } mutex_unlock(&pdev_list_mutex); } -- cgit v1.2.3-70-g09d2