Re: [PATCH v3 3/5] platform/x86: asus-armoury: add apu-mem control support

[Mario Limonciello <mario.limonciello@amd.com>]

On 9/18/2024 04:42, Luke D. Jones wrote:
> Implement the APU memory size control under the asus-armoury module using
> the fw_attributes class.
> 
> This allows the APU allocated memory size to be adjusted depending on
> the users priority. A reboot is required after change.
> 
> Signed-off-by: Luke D. Jones <luke@ljones.dev>
> ---
>   drivers/platform/x86/asus-armoury.c        | 114 +++++++++++++++++++++
>   include/linux/platform_data/x86/asus-wmi.h |   1 +
>   2 files changed, 115 insertions(+)
> 
> diff --git a/drivers/platform/x86/asus-armoury.c b/drivers/platform/x86/asus-armoury.c
> index 176ab5f105dd..b276c42f98d8 100644
> --- a/drivers/platform/x86/asus-armoury.c
> +++ b/drivers/platform/x86/asus-armoury.c
> @@ -456,6 +456,119 @@ static ssize_t egpu_enable_current_value_store(struct kobject *kobj, struct kobj
>   WMI_SHOW_INT(egpu_enable_current_value, "%d\n", ASUS_WMI_DEVID_EGPU);
>   ATTR_GROUP_BOOL_CUSTOM(egpu_enable, "egpu_enable", "Enable the eGPU (also disables dGPU)");
>   
> +/* Device memory available to APU */
> +
> +static ssize_t apu_mem_current_value_show(struct kobject *kobj, struct kobj_attribute *attr,
> +					  char *buf)
> +{
> +	int err;
> +	u32 mem;
> +
> +	err = asus_wmi_get_devstate_dsts(ASUS_WMI_DEVID_APU_MEM, &mem);
> +	if (err)
> +		return err;
> +
> +	switch (mem) {
> +	case 256:
> +		mem = 0;
> +		break;
> +	case 258:
> +		mem = 1;
> +		break;
> +	case 259:
> +		mem = 2;
> +		break;
> +	case 260:
> +		mem = 3;
> +		break;
> +	case 261:
> +		mem = 4;
> +		break;
> +	case 262:
> +		/* This is out of order and looks wrong but is correct */
> +		mem = 8;
> +		break;
> +	case 263:
> +		mem = 5;
> +		break;
> +	case 264:
> +		mem = 6;
> +		break;
> +	case 265:
> +		mem = 7;
> +		break;
> +	default:
> +		mem = 4;
> +		break;
> +	}
> +
> +	return sysfs_emit(buf, "%u\n", mem);
> +}
> +
> +static ssize_t apu_mem_current_value_store(struct kobject *kobj, struct kobj_attribute *attr,
> +					   const char *buf, size_t count)
> +{
> +	int result, err;
> +	u32 requested, mem;
> +
> +	result = kstrtou32(buf, 10, &requested);
> +	if (result)
> +		return result;
> +
> +	switch (requested) {
> +	case 0:
> +		mem = 0;
> +		break;
> +	case 1:
> +		mem = 258;
> +		break;
> +	case 2:
> +		mem = 259;
> +		break;
> +	case 3:
> +		mem = 260;
> +		break;
> +	case 4:
> +		mem = 261;
> +		break;
> +	case 5:
> +		mem = 263;
> +		break;
> +	case 6:
> +		mem = 264;
> +		break;
> +	case 7:
> +		mem = 265;
> +		break;
> +	case 8:
> +		/* This is out of order and looks wrong but is correct */
> +		mem = 262;
> +		break;
> +	default:
> +		return -EIO;
> +	}
> +
> +	err = asus_wmi_set_devstate(ASUS_WMI_DEVID_APU_MEM, mem, &result);
> +	if (err) {
> +		pr_warn("Failed to set apu_mem: %d\n", err);
> +		return err;
> +	}
> +
> +	pr_info("APU memory changed to %uGB, reboot required\n", requested);

This doesn't seem right.  If you requested "0", you just set APU memory 
to 0GB?

> +	sysfs_notify(kobj, NULL, attr->attr.name);
> +
> +	asus_set_reboot_and_signal_event();
> +
> +	return count;
> +}
> +
> +static ssize_t apu_mem_possible_values_show(struct kobject *kobj, struct kobj_attribute *attr,
> +					    char *buf)
> +{
> +	return sysfs_emit(buf, "0;1;2;3;4;5;6;7;8\n");

What exactly is the unit for 0-8?  It's obviously not a a multiple of 
base memory, is it a multiple of an adder?

Is this changing the VRAM allocation?  Like does 0 mean 256MB, 1 is 512 etc?

> +}
> +ATTR_GROUP_ENUM_CUSTOM(apu_mem, "apu_mem", "Set the available system memory for the APU to use");
> +
>   /* Simple attribute creation */
>   ATTR_GROUP_ROG_TUNABLE(ppt_pl1_spl, "ppt_pl1_spl", ASUS_WMI_DEVID_PPT_PL1_SPL, cpu_default,
>   		       cpu_min, cpu_max, 1, "Set the CPU slow package limit");
> @@ -511,6 +624,7 @@ static const struct asus_attr_group armoury_attr_groups[] = {
>   	{ &nv_temp_target_attr_group, ASUS_WMI_DEVID_NV_THERM_TARGET },
>   	{ &dgpu_base_tgp_attr_group, ASUS_WMI_DEVID_DGPU_BASE_TGP },
>   	{ &dgpu_tgp_attr_group, ASUS_WMI_DEVID_DGPU_SET_TGP },
> +	{ &apu_mem_attr_group, ASUS_WMI_DEVID_APU_MEM },
>   
>   	{ &charge_mode_attr_group, ASUS_WMI_DEVID_CHARGE_MODE },
>   	{ &boot_sound_attr_group, ASUS_WMI_DEVID_BOOT_SOUND },
> diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
> index 86629e621c61..e1aeafdf05d5 100644
> --- a/include/linux/platform_data/x86/asus-wmi.h
> +++ b/include/linux/platform_data/x86/asus-wmi.h
> @@ -136,6 +136,7 @@
>   
>   #define ASUS_WMI_DEVID_DGPU_BASE_TGP	0x00120099
>   #define ASUS_WMI_DEVID_DGPU_SET_TGP	0x00120098
> +#define ASUS_WMI_DEVID_APU_MEM		0x000600C1
>   
>   /* gpu mux switch, 0 = dGPU, 1 = Optimus */
>   #define ASUS_WMI_DEVID_GPU_MUX		0x00090016