Message-ID: <2a478609-f59d-4b8a-8e74-db0b30b94dfd@amd.com>
Date: Tue, 18 Nov 2025 14:52:40 -0600
From: Mario Limonciello <mario.limonciello@....com>
To: Denis Benato <benato.denis96@...il.com>,
 Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Cc: Denis Benato <denis.benato@...ux.dev>, LKML
 <linux-kernel@...r.kernel.org>, platform-driver-x86@...r.kernel.org,
 Hans de Goede <hansg@...nel.org>, "Luke D . Jones" <luke@...nes.dev>,
 Alok Tiwari <alok.a.tiwari@...cle.com>,
 Derek John Clark <derekjohn.clark@...il.com>,
 Mateusz Schyboll <dragonn@...pl>, porfet828@...il.com
Subject: Re: [PATCH] platform/x86: asus-armoury: make CPU cores interface
 readonly



On 11/18/2025 12:51 PM, Denis Benato wrote:
> 
> On 11/18/25 10:16, Ilpo Järvinen wrote:
>> On Tue, 18 Nov 2025, Denis Benato wrote:
>>
>>> On 11/18/25 01:57, Denis Benato wrote:
>>>> The CPU cores interface is inconsistent between AMD and Intel systems,
>>>> leading to probe failure: solve the problem taking following steps:
>>>> - make the interface read-only (avoid the possibility of bricks)
>>>> - do not fail if the interface returns unexpected data
>>>> - show interface errors at either info or debug level
>>> I felt like compile-time disabling the write endpoint after reading the comment
>>> from Mario while still keeping the core of everything that was said in an attempt
>>> to make everyone happy and preparing for the future.
>>>
>>> I can also evaluate the option to introduce a table for allowed models
>>> where the min number of cores is hardcoded for model as it is for TDP
>>> tunings: that way allowed values will be tested by someone...
>>> Material for another day.
>>>
>>> On a side note checkpatch says:
>>> ```
>>> WARNING: Argument '_fsname' is not used in function-like macro
>>> #293: FILE: drivers/platform/x86/asus-armoury.h:210:
>>> +#define ASUS_ATTR_GROUP_CORES(_attrname, _fsname, _dispname)           \
>>>          __ATTR_SHOW_FMT(scalar_increment, _attrname, "%d\n", 1);        \
>>>          __ATTR_SHOW_FMT(display_name, _attrname, "%s\n", _dispname);    \
>>>          static struct kobj_attribute attr_##_attrname##_current_value = \
>>> +               __ASUS_ATTR_CPU_CORES(_attrname, current_value);        \
>>>          static struct kobj_attribute attr_##_attrname##_default_value = \
>>>                  __ASUS_ATTR_RO(_attrname, default_value);               \
>>>          static struct kobj_attribute attr_##_attrname##_min_value =     \
>>> ```
>>>
>>> but _fsname name is used just below in the same macro:
>>> checkpatch.pl bug?
>>>> Links:
>>>> https://lore.kernel.org/all/20251114185337.578959-1-denis.benato@linux.dev/
>>>> https://lore.kernel.org/all/20251115145158.1172210-1-denis.benato@linux.dev/
>>>>
>>>> Suggested-by: Luke D. Jones <luke@...nes.dev>
>>>> Signed-off-by: Denis Benato <denis.benato@...ux.dev>
>>>> ---
>>>>   drivers/platform/x86/asus-armoury.c | 104 ++++++++++++++++++++++++----
>>>>   drivers/platform/x86/asus-armoury.h |  12 +++-
>>>>   2 files changed, 99 insertions(+), 17 deletions(-)
>>>>
>>>> diff --git a/drivers/platform/x86/asus-armoury.c b/drivers/platform/x86/asus-armoury.c
>>>> index 9f67218ecd14..abbbcd62d0eb 100644
>>>> --- a/drivers/platform/x86/asus-armoury.c
>>>> +++ b/drivers/platform/x86/asus-armoury.c
>>>> @@ -118,11 +118,14 @@ struct asus_armoury_priv {
>>>>   	 */
>>>>   	struct mutex egpu_mutex;
>>>>   
>>>> +#if IS_REACHABLE(CONFIG_ASUS_ARMOURY_CPU_CORES_RW)
>>>>   	/*
>>>>   	 * Mutex to prevent big/little core count changes writing to same
>>>>   	 * endpoint at the same time. Must lock during attr store.
>>>>   	 */
>>>>   	struct mutex cpu_core_mutex;
>>>> +#endif /* CONFIG_ASUS_ARMOURY_CPU_CORES_RW */
>>>> +
>>>>   	struct cpu_cores *cpu_cores;
>>>>   	bool cpu_cores_changeable;
>>>>   
>>>> @@ -136,7 +139,9 @@ struct asus_armoury_priv {
>>>>   static struct asus_armoury_priv asus_armoury = {
>>>>   	.egpu_mutex = __MUTEX_INITIALIZER(asus_armoury.egpu_mutex),
>>>>   
>>>> +#if IS_REACHABLE(CONFIG_ASUS_ARMOURY_CPU_CORES_RW)
>>>>   	.cpu_core_mutex = __MUTEX_INITIALIZER(asus_armoury.cpu_core_mutex),
>>>> +#endif /* CONFIG_ASUS_ARMOURY_CPU_CORES_RW */
>>>>   };
>>>>   
>>>>   struct fw_attrs_group {
>>>> @@ -285,6 +290,12 @@ static int armoury_set_devstate(struct kobj_attribute *attr,
>>>>   			return -EINVAL;
>>>>   		}
>>>>   		break;
>>>> +	case ASUS_WMI_DEVID_CORES_MAX:
>>>> +		/*
>>>> +		 * CPU cores max is a read-only property on supported devices.
>>>> +		 */
>>>> +		pr_err("Refusing to write to readonly devstate of CPU cores interface\n");
>>>> +		return -EINVAL;
>>>>   	default:
>>>>   		/* No known problems are known for this dev_id */
>>>>   		break;
>>>> @@ -803,6 +814,7 @@ static struct cpu_cores *init_cpu_cores_ctrl(void)
>>>>   		return ERR_PTR(-ENODEV);
>>>>   	}
>>>>   
>>>> +	pr_debug("CPU cores control interface max cores read 0%x.\n", cores);
>>>>   	cores_p->max_power_cores = FIELD_GET(ASUS_POWER_CORE_MASK, cores);
>>>>   	cores_p->max_perf_cores = FIELD_GET(ASUS_PERF_CORE_MASK, cores);
>>>>   
>>>> @@ -812,16 +824,30 @@ static struct cpu_cores *init_cpu_cores_ctrl(void)
>>>>   		return ERR_PTR(-EIO);
>>>>   	}
>>>>   
>>>> +	pr_debug("CPU cores control interface active cores read 0%x.\n", cores);
>>>>   	cores_p->cur_power_cores = FIELD_GET(ASUS_POWER_CORE_MASK, cores);
>>>>   	cores_p->cur_perf_cores = FIELD_GET(ASUS_PERF_CORE_MASK, cores);
>>>>   
>>>>   	cores_p->min_power_cores = CPU_POWR_CORE_COUNT_MIN;
>>>>   	cores_p->min_perf_cores = CPU_PERF_CORE_COUNT_MIN;
>>>>   
>>>> +	if (cores_p->min_perf_cores > cores_p->max_perf_cores) {
>>>> +		pr_info("Invalid CPU performance cores count detected: min: %u, max: %u, current: %u\n",
>>>> +		       cores_p->min_perf_cores,
>>>> +		       cores_p->max_perf_cores,
>>>> +		       cores_p->cur_perf_cores
>>>> +		);
>>>> +		return ERR_PTR(-EINVAL);
>>>> +	}
>>>> +
>>>>   	if ((cores_p->min_perf_cores > cores_p->max_perf_cores) ||
>>>>   	    (cores_p->min_power_cores > cores_p->max_power_cores)
>>>>   	) {
>>>> -		pr_err("Invalid CPU cores count detected: interface is not safe to be used.\n");
>>>> +		pr_info("Invalid CPU efficiency cores count detected: min: %u, max: %u, current: %u\n",
>>>> +		       cores_p->min_power_cores,
>>>> +		       cores_p->max_power_cores,
>>>> +		       cores_p->cur_power_cores
>>>> +		);
>>>>   		return ERR_PTR(-EINVAL);
>>>>   	}
>>>>   
>>>> @@ -836,6 +862,24 @@ static struct cpu_cores *init_cpu_cores_ctrl(void)
>>>>   	return no_free_ptr(cores_p);
>>>>   }
>>>>   
>>>> +/**
>>>> + * cores_value_show() - Get the core count for the specified core type.
>>>> + * @kobj: The kobject associated to caller.
>>>> + * @attr: The kobj_attribute associated to caller.
>>>> + * @buf: The buffer that will be used to sysfs_emit.
>>>> + * @core_type: The core type (performance or efficiency).
>>>> + * @core_value: min, max or current count for the specified cores type.
>>>> + *
>>>> + * Intended usage is from sysfs attribute reading a CPU core count.
>>>> + *
>>>> + * This function assumes asus_armoury.cpu_cores is already initialized,
>>>> + * therefore the compatibility of the interface has already been checked.
>>>> + *
>>>> + * Returns:
>>>> + * * %-EINVAL	- invalid core value type.
>>>> + * * %0		- successful and buf is filled by sysfs_emit.
>>>> + * * %other	- error from sysfs_emit.
>>>> + */
>>>>   static ssize_t cores_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf,
>>>>   				enum cpu_core_type core_type, enum cpu_core_value core_value)
>>>>   {
>>>> @@ -865,6 +909,7 @@ static ssize_t cores_value_show(struct kobject *kobj, struct kobj_attribute *att
>>>>   	return sysfs_emit(buf, "%u\n", cpu_core_value);
>>>>   }
>>>>   
>>>> +#if IS_REACHABLE(CONFIG_ASUS_ARMOURY_CPU_CORES_RW)
>>>>   static ssize_t cores_current_value_store(struct kobject *kobj, struct kobj_attribute *attr,
>>>>   					 const char *buf, enum cpu_core_type core_type)
>>>>   {
>>>> @@ -919,6 +964,7 @@ static ssize_t cores_current_value_store(struct kobject *kobj, struct kobj_attri
>>>>   
>>>>   	return 0;
>>>>   }
>>>> +#endif /* CONFIG_ASUS_ARMOURY_CPU_CORES_RW */
>>>>   
>>>>   static ssize_t cores_performance_min_value_show(struct kobject *kobj,
>>>>   						struct kobj_attribute *attr, char *buf)
>>>> @@ -944,6 +990,7 @@ static ssize_t cores_performance_current_value_show(struct kobject *kobj,
>>>>   	return cores_value_show(kobj, attr, buf, CPU_CORE_PERF, CPU_CORE_CURRENT);
>>>>   }
>>>>   
>>>> +#if IS_REACHABLE(CONFIG_ASUS_ARMOURY_CPU_CORES_RW)
>>>>   static ssize_t cores_performance_current_value_store(struct kobject *kobj,
>>>>   						     struct kobj_attribute *attr,
>>>>   						     const char *buf, size_t count)
>>>> @@ -956,8 +1003,9 @@ static ssize_t cores_performance_current_value_store(struct kobject *kobj,
>>>>   
>>>>   	return count;
>>>>   }
>>>> -ASUS_ATTR_GROUP_CORES_RW(cores_performance, "cores_performance",
>>>> -			 "Set the max available performance cores");
>>>> +#endif /* CONFIG_ASUS_ARMOURY_CPU_CORES_RW */
>>>> +ASUS_ATTR_GROUP_CORES(cores_performance, "cores_performance",
>>>> +			 "Get available performance cores");
>>>>   
>>>>   /* Define helper to access the current power mode tunable values */
>>>>   static inline struct rog_tunables *get_current_tunables(void)
>>>> @@ -992,6 +1040,7 @@ static ssize_t cores_efficiency_current_value_show(struct kobject *kobj,
>>>>   	return cores_value_show(kobj, attr, buf, CPU_CORE_POWER, CPU_CORE_CURRENT);
>>>>   }
>>>>   
>>>> +#if IS_REACHABLE(CONFIG_ASUS_ARMOURY_CPU_CORES_RW)
>>>>   static ssize_t cores_efficiency_current_value_store(struct kobject *kobj,
>>>>   						    struct kobj_attribute *attr, const char *buf,
>>>>   						    size_t count)
>>>> @@ -1004,8 +1053,9 @@ static ssize_t cores_efficiency_current_value_store(struct kobject *kobj,
>>>>   
>>>>   	return count;
>>>>   }
>>>> -ASUS_ATTR_GROUP_CORES_RW(cores_efficiency, "cores_efficiency",
>>>> -		    "Set the max available efficiency cores");
>>>> +#endif /* CONFIG_ASUS_ARMOURY_CPU_CORES_RW */
>>>> +ASUS_ATTR_GROUP_CORES(cores_efficiency, "cores_efficiency",
>>>> +		    "Get available efficiency cores");
>>>>   
>>>>   /* Simple attribute creation */
>>>>   ASUS_ATTR_GROUP_ENUM_INT_RO(charge_mode, "charge_mode", ASUS_WMI_DEVID_CHARGE_MODE, "0;1;2\n",
>>>> @@ -1048,8 +1098,6 @@ static const struct asus_attr_group armoury_attr_groups[] = {
>>>>   	{ &egpu_enable_attr_group, ASUS_WMI_DEVID_EGPU },
>>>>   	{ &dgpu_disable_attr_group, ASUS_WMI_DEVID_DGPU },
>>>>   	{ &apu_mem_attr_group, ASUS_WMI_DEVID_APU_MEM },
>>>> -	{ &cores_efficiency_attr_group, ASUS_WMI_DEVID_CORES_MAX },
>>>> -	{ &cores_performance_attr_group, ASUS_WMI_DEVID_CORES_MAX },
>>>>   
>>>>   	{ &ppt_pl1_spl_attr_group, ASUS_WMI_DEVID_PPT_PL1_SPL },
>>>>   	{ &ppt_pl2_sppt_attr_group, ASUS_WMI_DEVID_PPT_PL2_SPPT },
>>>> @@ -1191,6 +1239,22 @@ static int asus_fw_attr_add(void)
>>>>   		}
>>>>   	}
>>>>   
>>>> +	if (asus_armoury.cpu_cores != NULL) {
>>>> +		err = sysfs_create_group(&asus_armoury.fw_attr_kset->kobj,
>>>> +					&cores_efficiency_attr_group);
>>>> +		if (err) {
>>>> +			pr_err("Failed to create sysfs-group for cpu efficiency cores: %d\n", err);
>>>> +			goto err_remove_cores_efficiency_group;
>>>> +		}
>>>> +
>>>> +		err = sysfs_create_group(&asus_armoury.fw_attr_kset->kobj,
>>>> +					&cores_performance_attr_group);
>>>> +		if (err) {
>>>> +			pr_err("Failed to create sysfs-group for cpu performance cores: %d\n", err);
>>>> +			goto err_remove_cores_performance_group;
>>>> +		}
>>>> +	}
>>>> +
>>>>   	for (i = 0; i < ARRAY_SIZE(armoury_attr_groups); i++) {
>>>>   		if (!armoury_has_devstate(armoury_attr_groups[i].wmi_devid))
>>>>   			continue;
>>>> @@ -1230,6 +1294,12 @@ static int asus_fw_attr_add(void)
>>>>   	}
>>>>   	if (asus_armoury.gpu_mux_dev_id)
>>>>   		sysfs_remove_group(&asus_armoury.fw_attr_kset->kobj, &gpu_mux_mode_attr_group);
>>>> +err_remove_cores_performance_group:
>>>> +	if (asus_armoury.cpu_cores != NULL)
>>>> +		sysfs_remove_group(&asus_armoury.fw_attr_kset->kobj, &cores_performance_attr_group);
>>>> +err_remove_cores_efficiency_group:
>>>> +	if (asus_armoury.cpu_cores != NULL)
>>>> +		sysfs_remove_group(&asus_armoury.fw_attr_kset->kobj, &cores_efficiency_attr_group);
>>>>   err_remove_mini_led_group:
>>>>   	if (asus_armoury.mini_led_dev_id)
>>>>   		sysfs_remove_group(&asus_armoury.fw_attr_kset->kobj, &mini_led_mode_attr_group);
>>>> @@ -1375,7 +1445,6 @@ static int __init asus_fw_init(void)
>>>>   {
>>>>   	char *wmi_uid;
>>>>   	struct cpu_cores *cpu_cores_ctrl;
>>>> -	int err;
>>>>   
>>>>   	wmi_uid = wmi_get_acpi_device_uid(ASUS_WMI_MGMT_GUID);
>>>>   	if (!wmi_uid)
>>>> @@ -1389,16 +1458,14 @@ static int __init asus_fw_init(void)
>>>>   		return -ENODEV;
>>>>   
>>>>   	asus_armoury.cpu_cores_changeable = false;
>>>> +	asus_armoury.cpu_cores = NULL;
>>>>   	if (armoury_has_devstate(ASUS_WMI_DEVID_CORES_MAX)) {
>>>>   		cpu_cores_ctrl = init_cpu_cores_ctrl();
>>>> -		if (IS_ERR(cpu_cores_ctrl)) {
>>>> -			err = PTR_ERR(cpu_cores_ctrl);
>>>> -			pr_err("Could not initialise CPU core control: %d\n", err);
>>>> -			return err;
>>>> +		if (!IS_ERR(cpu_cores_ctrl)) {
>>>> +			pr_debug("CPU cores control available.\n");
>>>> +			asus_armoury.cpu_cores = cpu_cores_ctrl;
>>>> +			asus_armoury.cpu_cores_changeable = true;
>>>>   		}
>>>> -
>>>> -		asus_armoury.cpu_cores = cpu_cores_ctrl;
>>>> -		asus_armoury.cpu_cores_changeable = true;
>>>>   	}
>>>>   
>>>>   	init_rog_tunables();
>>>> @@ -1417,6 +1484,13 @@ static void __exit asus_fw_exit(void)
>>>>   					   armoury_attr_groups[i].attr_group);
>>>>   	}
>>>>   
>>>> +	if (asus_armoury.cpu_cores != NULL) {
>>>> +		sysfs_remove_group(&asus_armoury.fw_attr_kset->kobj,
>>>> +				   &cores_performance_attr_group);
>>>> +		sysfs_remove_group(&asus_armoury.fw_attr_kset->kobj,
>>>> +				   &cores_efficiency_attr_group);
>>>> +	}
>>>> +
>>>>   	if (asus_armoury.gpu_mux_dev_id)
>>>>   		sysfs_remove_group(&asus_armoury.fw_attr_kset->kobj, &gpu_mux_mode_attr_group);
>>>>   
>>>> diff --git a/drivers/platform/x86/asus-armoury.h b/drivers/platform/x86/asus-armoury.h
>>>> index 2f05a2e0cab3..6b2bfe763d23 100644
>>>> --- a/drivers/platform/x86/asus-armoury.h
>>>> +++ b/drivers/platform/x86/asus-armoury.h
>>>> @@ -198,12 +198,20 @@ ssize_t armoury_attr_uint_show(struct kobject *kobj, struct kobj_attribute *attr
>>>>   		.name = _fsname, .attrs = _attrname##_attrs			\
>>>>   	}
>>>>   
>>>> +#if IS_REACHABLE(CONFIG_ASUS_ARMOURY_CPU_CORES_RW)
>>>> +	#define __ASUS_ATTR_CPU_CORES(_attrname, __attrval) \
>>>> +		__ASUS_ATTR_RW(_attrname, __attrval)
>>>> +#else
>>>> +	#define __ASUS_ATTR_CPU_CORES(_attrname, __attrval) \
>>>> +		__ASUS_ATTR_RO(_attrname, __attrval)
>>>> +#endif /* CONFIG_ASUS_ARMOURY_CPU_CORES_RW */
>>>> +
>>>>   /* CPU core attributes need a little different in setup */
>>>> -#define ASUS_ATTR_GROUP_CORES_RW(_attrname, _fsname, _dispname)		\
>>>> +#define ASUS_ATTR_GROUP_CORES(_attrname, _fsname, _dispname)		\
>>>>   	__ATTR_SHOW_FMT(scalar_increment, _attrname, "%d\n", 1);	\
>>>>   	__ATTR_SHOW_FMT(display_name, _attrname, "%s\n", _dispname);	\
>>>>   	static struct kobj_attribute attr_##_attrname##_current_value =	\
>>>> -		__ASUS_ATTR_RW(_attrname, current_value);		\
>>>> +		__ASUS_ATTR_CPU_CORES(_attrname, current_value);	\
>>>>   	static struct kobj_attribute attr_##_attrname##_default_value = \
>>>>   		__ASUS_ATTR_RO(_attrname, default_value);		\
>>>>   	static struct kobj_attribute attr_##_attrname##_min_value =	\
>> Hi Denis,
> Hi!
>> This cores thing has unfortunately turned into too much of a mess, a fixup
>> after fixup, disagreement of even what should be included and what not.
> I'm sorry for the trouble.
>> I'm really sorry for all the extra trouble these people are putting you
>> through as apparently even 17 versions of the main patch series weren't
>> enough to get them to stretch their fingers over the keyboard :-/.
> I was aware of what I was running into when I accepted
> Luke's request to maintain asus-related things :)
> 
> The interface is being evolving since it's what asus keeps
> integrating and changing on new hardware,
> so unexpected things are to be expected... hah!
>> I've now dropped the cores patch from the review-ilpo-next branch but
>> tried to keep the rest. Please check I didn't make any stupid mistakes
>> while resolving the resulting conflicts with the ppt/nv change, at least
>> the diff against the removal patch looked promising. If there's an issue,
>> please just provide a clean v18 of the main series without the cores patch
>> so I can replace.
> Thanks! Looks good to me too, I have asked asus-linux kernel-man
> to distribute this patchset taken from pdx86 repo: if you don't hear for
> me in 2-3 hours the world isn't burning :D
>> If you want to send a clean version of the cores patch (separately), I can
>> consider it after giving enough time for people to comment.
>>
> Going forward I think the best approach is to make the interface
> compatible with new hardware and useful for who needs it:
> - RO by default and disregarded by the driver in case of funny business
> - RW for hardware that was requested and tested, similar to the TDP
>    so that I can also be confident on what minimum cores count are per-model
>    instead of relying on a macro and hoping for the best
> - Integrating your suggestions
> 
> And that should satisfy everybody and make the interface safe.
> 
> Please everybody, let me know if this is an acceptable solution
> that would make everyone involved happy: from developers
> to final users (especially those who use this feature in Windows).
> 
> Thank you all,
> Denis


It's up to you at the end of the day if you want some machines to be opt 
in to RW, but I don't think this fair to treat this the same as TDP.

We only have one way to change TDP on these machines - the BIOS interface.

For parking of cores there is the BIOS method or Linux native support 
for offlining cores.

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