platform/x86: asus-armoury: add apu-mem control support

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.

Co-developed-by: Denis Benato <denis.benato@linux.dev>
Signed-off-by: Denis Benato <denis.benato@linux.dev>
Signed-off-by: Luke D. Jones <luke@ljones.dev>
Link: https://patch.msgid.link/20251102215319.3126879-5-denis.benato@linux.dev
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/asus-armoury.c b/drivers/platform/x86/asus-armoury.c
index f0cb973a487e213ef7ac2138cdac84e9c7217793..1b972260c5dd2168dff28448c17f7b19fa92fb09 100644 (file)
--- a/drivers/platform/x86/asus-armoury.c
+++ b/drivers/platform/x86/asus-armoury.c
@@ -174,6 +174,7 @@ static int armoury_get_devstate(struct kobj_attribute *attr, u32 *retval, u32 de
  * and should perform relevant checks.
  *
  * Returns:
+ * * %-EINVAL  - attempt to set a dangerous or unsupported value.
  * * %-EIO     - WMI function returned an error.
  * * %0                - successful and retval is filled.
  * * %other    - error from WMI call.
@@ -184,6 +185,26 @@ static int armoury_set_devstate(struct kobj_attribute *attr,
        u32 result;
        int err;
 
+       /*
+        * Prevent developers from bricking devices or issuing dangerous
+        * commands that can be difficult or impossible to recover from.
+        */
+       switch (dev_id) {
+       case ASUS_WMI_DEVID_APU_MEM:
+               /*
+                * A hard reset might suffice to save the device,
+                * but there is no value in sending these commands.
+                */
+               if (value == 0x100 || value == 0x101) {
+                       pr_err("Refusing to set APU memory to unsafe value: 0x%x\n", value);
+                       return -EINVAL;
+               }
+               break;
+       default:
+               /* No problems are known for this dev_id */
+               break;
+       }
+
        err = asus_wmi_set_devstate(dev_id, value, retval ? retval : &result);
        if (err) {
                if (attr)
@@ -599,6 +620,82 @@ static ssize_t egpu_enable_possible_values_show(struct kobject *kobj, struct kob
 }
 ASUS_ATTR_GROUP_ENUM(egpu_enable, "egpu_enable", "Enable the eGPU (also disables dGPU)");
 
+/* Device memory available to APU */
+
+/*
+ * Values map for APU reserved memory (index + 1 number of GB).
+ * Some looks out of order, but are actually correct.
+ */
+static u32 apu_mem_map[] = {
+       [0] = 0x000, /* called "AUTO" on the BIOS, is the minimum available */
+       [1] = 0x102,
+       [2] = 0x103,
+       [3] = 0x104,
+       [4] = 0x105,
+       [5] = 0x107,
+       [6] = 0x108,
+       [7] = 0x109,
+       [8] = 0x106,
+};
+
+static ssize_t apu_mem_current_value_show(struct kobject *kobj, struct kobj_attribute *attr,
+                                         char *buf)
+{
+       int err;
+       u32 mem;
+
+       err = armoury_get_devstate(attr, &mem, ASUS_WMI_DEVID_APU_MEM);
+       if (err)
+               return err;
+
+       /* After 0x000 is set, a read will return 0x100 */
+       if (mem == 0x100)
+               return sysfs_emit(buf, "0\n");
+
+       for (unsigned int i = 0; i < ARRAY_SIZE(apu_mem_map); i++) {
+               if (apu_mem_map[i] == mem)
+                       return sysfs_emit(buf, "%u\n", i);
+       }
+
+       pr_warn("Unrecognised value for APU mem 0x%08x\n", mem);
+       return -EIO;
+}
+
+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;
+
+       if (requested >= ARRAY_SIZE(apu_mem_map))
+               return -EINVAL;
+       mem = apu_mem_map[requested];
+
+       err = armoury_set_devstate(attr, mem, NULL, ASUS_WMI_DEVID_APU_MEM);
+       if (err) {
+               pr_warn("Failed to set apu_mem 0x%x: %d\n", mem, err);
+               return err;
+       }
+
+       pr_info("APU memory changed to %uGB, reboot required\n", requested + 1);
+       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 armoury_attr_enum_list(buf, ARRAY_SIZE(apu_mem_map));
+}
+ASUS_ATTR_GROUP_ENUM(apu_mem, "apu_mem", "Set available system RAM (in GB) for the APU to use");
+
 /* Simple attribute creation */
 ASUS_ATTR_GROUP_ENUM_INT_RO(charge_mode, "charge_mode", ASUS_WMI_DEVID_CHARGE_MODE, "0;1;2\n",
                            "Show the current mode of charging");
@@ -618,6 +715,7 @@ static const struct asus_attr_group armoury_attr_groups[] = {
        { &egpu_connected_attr_group, ASUS_WMI_DEVID_EGPU_CONNECTED },
        { &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 },
 
        { &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 3cc235b20be45013b55f5923dad9e92b4db605d6..9a6433d08973a9f71f1e33b85862b72938c416fd 100644 (file)
--- a/include/linux/platform_data/x86/asus-wmi.h
+++ b/include/linux/platform_data/x86/asus-wmi.h
@@ -136,6 +136,8 @@
 /* dgpu on/off */
 #define ASUS_WMI_DEVID_DGPU            0x00090020
 
+#define ASUS_WMI_DEVID_APU_MEM         0x000600C1
+
 /* gpu mux switch, 0 = dGPU, 1 = Optimus */
 #define ASUS_WMI_DEVID_GPU_MUX         0x00090016
 #define ASUS_WMI_DEVID_GPU_MUX_VIVO    0x00090026