linux-kernel - [PATCH 7/9] platform/x86: asus-wmi: add enable/disable CPU cores

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Date: Tue, 28 May 2024 13:36:24 +1200
From: "Luke D. Jones" <luke@...nes.dev>
To: hdegoede@...hat.com
Cc: ilpo.jarvinen@...ux.intel.com,
	corentin.chary@...il.com,
	platform-driver-x86@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	"Luke D. Jones" <luke@...nes.dev>
Subject: [PATCH 7/9] platform/x86: asus-wmi: add enable/disable CPU cores

Exposes the WMI functions for enable/disable of performance and
efficiency cores on some laptop models (largely Intel only).

Signed-off-by: Luke D. Jones <luke@...nes.dev>
---
 .../ABI/testing/sysfs-platform-asus-wmi       | 19 ++++++++
 drivers/platform/x86/asus-wmi.c               | 45 +++++++++++++++++++
 include/linux/platform_data/x86/asus-wmi.h    |  5 +++
 3 files changed, 69 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-platform-asus-wmi b/Documentation/ABI/testing/sysfs-platform-asus-wmi
index 3b4eeea75b7b..ac881e72e374 100644
--- a/Documentation/ABI/testing/sysfs-platform-asus-wmi
+++ b/Documentation/ABI/testing/sysfs-platform-asus-wmi
@@ -226,3 +226,22 @@ Description:
 		Set panel to UHD or FHD mode
 			* 0 - UHD,
 			* 1 - FHD
+
+What:		/sys/devices/platform/<platform>/cores_enabled
+Date:		Jun 2024
+KernelVersion:	6.11
+Contact:	"Luke Jones" <luke@...nes.dev>
+Description:
+		Enable/disable efficiency and performance cores. The format is
+		0x[E][P] where [E] is the efficiency core count, and [P] is
+		the perfromance core count. If the core count is a single digit
+		it is preceded by a 0 such as 0x0406; E=4, P=6, 0x1006; E=10, P=6
+
+What:		/sys/devices/platform/<platform>/cores_max
+Date:		Jun 2024
+KernelVersion:	6.11
+Contact:	"Luke Jones" <luke@...nes.dev>
+Description:
+		Show the maximum performance and efficiency core countin format
+		0x[E][P] where [E] is the efficiency core count, and [P] is
+		the perfromance core count.
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 4b045f1828f1..f62a36dfcd4b 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -815,6 +815,46 @@ static ssize_t panel_fhd_store(struct device *dev,
 WMI_SIMPLE_SHOW(panel_fhd, "%d\n", ASUS_WMI_DEVID_PANEL_FHD);
 static DEVICE_ATTR_RW(panel_fhd);
 
+/* Efficiency and Performance core control **********************************/
+static ssize_t cores_enabled_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct asus_wmi *asus = dev_get_drvdata(dev);
+	int result, err;
+	u32 cores, max;
+
+	result = kstrtou32(buf, 16, &cores);
+	if (result)
+		return result;
+
+	err = asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_CORES_MAX, &max);
+	if (err < 0)
+		return err;
+
+	if (cores > max) {
+		pr_warn("Core count 0x%x exceeds max: 0x%x\n", cores, max);
+		return -EIO;
+	}
+
+	err = asus_wmi_set_devstate(ASUS_WMI_DEVID_CORES_SET, cores, &result);
+	if (err) {
+		pr_warn("Failed to set cores_enabled: %d\n", err);
+		return err;
+	}
+
+	pr_info("Enabled core count changed, reboot required\n");
+	sysfs_notify(&asus->platform_device->dev.kobj, NULL, "cores_enabled");
+
+	return count;
+}
+
+WMI_SIMPLE_SHOW(cores_enabled, "0x%x\n", ASUS_WMI_DEVID_CORES_SET);
+static DEVICE_ATTR_RW(cores_enabled);
+
+WMI_SIMPLE_SHOW(cores_max, "0x%x\n", ASUS_WMI_DEVID_CORES_MAX);
+static DEVICE_ATTR_RO(cores_max);
+
 /* Tablet mode ****************************************************************/
 
 static void asus_wmi_tablet_mode_get_state(struct asus_wmi *asus)
@@ -4058,6 +4098,8 @@ static struct attribute *platform_attributes[] = {
 	&dev_attr_boot_sound.attr,
 	&dev_attr_panel_od.attr,
 	&dev_attr_panel_fhd.attr,
+	&dev_attr_cores_enabled.attr,
+	&dev_attr_cores_max.attr,
 	&dev_attr_mini_led_mode.attr,
 	&dev_attr_available_mini_led_mode.attr,
 	NULL
@@ -4131,6 +4173,9 @@ static umode_t asus_sysfs_is_visible(struct kobject *kobj,
 		devid = ASUS_WMI_DEVID_PANEL_OD;
 	else if (attr == &dev_attr_panel_fhd.attr)
 		devid = ASUS_WMI_DEVID_PANEL_FHD;
+	else if (attr == &dev_attr_cores_enabled.attr
+		|| attr == &dev_attr_cores_max.attr)
+		ok = asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_CORES_SET);
 	else if (attr == &dev_attr_mini_led_mode.attr)
 		ok = asus->mini_led_dev_id != 0;
 	else if (attr == &dev_attr_available_mini_led_mode.attr)
diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
index 6c51d41ffc20..5a56e7e97785 100644
--- a/include/linux/platform_data/x86/asus-wmi.h
+++ b/include/linux/platform_data/x86/asus-wmi.h
@@ -116,6 +116,11 @@
 /* Charging mode - 1=Barrel, 2=USB */
 #define ASUS_WMI_DEVID_CHARGE_MODE	0x0012006C
 
+/* Intel E-core and P-core configuration in a format 0x0[E]0[P] */
+#define ASUS_WMI_DEVID_CORES_SET	0x001200D2
+ /* Maximum Intel E-core and P-core availability */
+#define ASUS_WMI_DEVID_CORES_MAX	0x001200D3
+
 /* MCU powersave mode */
 #define ASUS_WMI_DEVID_MCU_POWERSAVE   0x001200E2
 
-- 
2.45.1