refactor(inject/host/windows): hoist the shared SwCreateCtx into gamepad_raii (G14)

The `SwDeviceCreate` completion-callback context (`SwCreateCtx`, the
`sw_create_cb` extern callback, and the `instance_id()` accessor) was
copy-pasted byte-for-byte in the XUSB (`gamepad_windows.rs`) and
DualSense/DS4 (`dualsense_windows.rs`) backends. Hoist the one copy into
`gamepad_raii.rs` as `pub(super)`; both `create_swdevice` bodies now build
the shared type and pass the shared callback. Prunes the now-orphaned
HRESULT/SetEvent/HANDLE imports from the two siblings.

Pure move + dedup, no behavior change. Windows-verified with the rest of
Phase 3 (clippy --all-targets -D warnings).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/punktfunk-host/src/inject/windows/dualsense_windows.rs

@@ -21,19 +21,19 @@ use super::dualsense_proto::{
     parse_ds_output, serialize_state, DsFeedback, DsState, DS_INPUT_REPORT_LEN, DS_TOUCH_H,
     DS_TOUCH_W,
 };
-use super::gamepad_raii::PadChannel;
+use super::gamepad_raii::{sw_create_cb, PadChannel, SwCreateCtx};
 use crate::gamestream::gamepad::{GamepadEvent, MAX_PADS};
 use crate::inject::pad_gate::PadGate;
 use anyhow::{anyhow, Result};
 use punktfunk_core::quic::{HidOutput, RichInput};
 use std::ffi::c_void;
 use std::time::{Duration, Instant};
-use windows::core::{w, GUID, HRESULT, PCWSTR};
+use windows::core::{w, GUID, PCWSTR};
 use windows::Win32::Devices::Enumeration::Pnp::{
     SwDeviceClose, SwDeviceCreate, HSWDEVICE, SW_DEVICE_CREATE_INFO,
 };
-use windows::Win32::Foundation::{CloseHandle, E_FAIL, HANDLE, WAIT_OBJECT_0};
+use windows::Win32::Foundation::{CloseHandle, E_FAIL, WAIT_OBJECT_0};
-use windows::Win32::System::Threading::{CreateEventW, SetEvent, WaitForSingleObject};
+use windows::Win32::System::Threading::{CreateEventW, WaitForSingleObject};
 
 /// Shared-section layout — the single source of truth is [`pf_driver_proto::gamepad::PadShm`] (offset
 /// asserts pin every field; the `pf_dualsense` driver maps the same struct). Derive the size/offsets/magic
@@ -72,50 +72,6 @@ struct DsWinPad {
     last_out_seq: u32,
 }
 
-/// Context for the `SwDeviceCreate` completion callback: an event to signal, the HRESULT it reports,
-/// and the PnP instance id PnP assigned (captured for devnode health diagnostics).
-#[repr(C)]
-struct SwCreateCtx {
-    event: HANDLE,
-    result: HRESULT,
-    instance_id: [u16; 128],
-}
-
-/// `SwDeviceCreate` fires this once PnP has enumerated the device; stash the result and wake the
-/// creator, which blocks on the event (so there's no concurrent access to `*ctx`).
-unsafe extern "system" fn sw_create_cb(
-    _dev: HSWDEVICE,
-    result: HRESULT,
-    ctx: *const c_void,
-    id: PCWSTR,
-) {
-    if !ctx.is_null() {
-        // SAFETY: ctx is the &mut SwCreateCtx the creator passed; it outlives this callback (the
-        // creator blocks on the event). `id` is a NUL-terminated string for the callback's duration.
-        unsafe {
-            let c = ctx as *mut SwCreateCtx;
-            (*c).result = result;
-            if !id.is_null() {
-                for i in 0..(*c).instance_id.len() - 1 {
-                    let ch = *id.0.add(i);
-                    (*c).instance_id[i] = ch;
-                    if ch == 0 {
-                        break;
-                    }
-                }
-            }
-            let _ = SetEvent((*c).event);
-        }
-    }
-}
-
-impl SwCreateCtx {
-    fn instance_id(&self) -> Option<String> {
-        let len = self.instance_id.iter().position(|&c| c == 0)?;
-        (len > 0).then(|| String::from_utf16_lossy(&self.instance_id[..len]))
-    }
-}
-
 /// The PnP identity for a virtual controller devnode — varies by controller type so the same
 /// [`create_swdevice`] builds a DualSense (`VID_054C&PID_0CE6`) or a DualShock 4
 /// (`VID_054C&PID_09CC`). The fields map onto the `SW_DEVICE_CREATE_INFO` identity discussed below.

crates/punktfunk-host/src/inject/windows/gamepad_raii.rs

@@ -22,11 +22,12 @@
 
 use anyhow::{anyhow, bail, Context, Result};
 use pf_driver_proto::gamepad::{PadBootstrap, BOOT_MAGIC, GAMEPAD_PROTO_VERSION};
+use std::ffi::c_void;
 use std::os::windows::io::{AsRawHandle, FromRawHandle, OwnedHandle};
 use std::sync::atomic::{fence, AtomicU32, AtomicU64, Ordering};
 use std::sync::OnceLock;
 use std::time::{Duration, Instant};
-use windows::core::{w, HSTRING, PCWSTR};
+use windows::core::{w, HRESULT, HSTRING, PCWSTR};
 use windows::Win32::Devices::DeviceAndDriverInstallation::{
     CM_Get_DevNode_Status, CM_Locate_DevNodeW, CM_DEVNODE_STATUS_FLAGS, CM_LOCATE_DEVNODE_NORMAL,
     CM_PROB, CR_SUCCESS, DN_DRIVER_LOADED, DN_HAS_PROBLEM, DN_STARTED,
@@ -45,7 +46,7 @@ use windows::Win32::System::Memory::{
     MEMORY_MAPPED_VIEW_ADDRESS, PAGE_READWRITE,
 };
 use windows::Win32::System::Threading::{
-    GetCurrentProcess, OpenProcess, PROCESS_DUP_HANDLE, PROCESS_QUERY_LIMITED_INFORMATION,
+    GetCurrentProcess, OpenProcess, SetEvent, PROCESS_DUP_HANDLE, PROCESS_QUERY_LIMITED_INFORMATION,
 };
 
 /// Least access the pad driver needs on the duplicated DATA section: it only MAPS it read/write, so
@@ -403,6 +404,53 @@ impl PadChannel {
     }
 }
 
+/// Context for the `SwDeviceCreate` completion callback: an event to signal, the HRESULT it reports,
+/// and the PnP instance id PnP assigned (captured for devnode health diagnostics). Shared by every
+/// Windows companion backend (XUSB / DualSense / DS4): each `create_swdevice` builds one, hands it to
+/// `SwDeviceCreate` alongside [`sw_create_cb`], and reads [`instance_id`](Self::instance_id) once the
+/// callback has signalled.
+#[repr(C)]
+pub(super) struct SwCreateCtx {
+    pub(super) event: HANDLE,
+    pub(super) result: HRESULT,
+    pub(super) instance_id: [u16; 128],
+}
+
+/// `SwDeviceCreate` fires this once PnP has enumerated the device; stash the result and wake the
+/// creator, which blocks on the event (so there's no concurrent access to `*ctx`).
+pub(super) unsafe extern "system" fn sw_create_cb(
+    _dev: HSWDEVICE,
+    result: HRESULT,
+    ctx: *const c_void,
+    id: PCWSTR,
+) {
+    if !ctx.is_null() {
+        // SAFETY: ctx is the &mut SwCreateCtx the creator passed; it outlives this callback (the
+        // creator blocks on the event). `id` is a NUL-terminated string for the callback's duration.
+        unsafe {
+            let c = ctx as *mut SwCreateCtx;
+            (*c).result = result;
+            if !id.is_null() {
+                for i in 0..(*c).instance_id.len() - 1 {
+                    let ch = *id.0.add(i);
+                    (*c).instance_id[i] = ch;
+                    if ch == 0 {
+                        break;
+                    }
+                }
+            }
+            let _ = SetEvent((*c).event);
+        }
+    }
+}
+
+impl SwCreateCtx {
+    pub(super) fn instance_id(&self) -> Option<String> {
+        let len = self.instance_id.iter().position(|&c| c == 0)?;
+        (len > 0).then(|| String::from_utf16_lossy(&self.instance_id[..len]))
+    }
+}
+
 /// A `SwDeviceCreate`'d software devnode; drop removes it via `SwDeviceClose`. Replaces the manual
 /// `SwDeviceClose` each backend used to call in its `Drop`.
 pub(super) struct SwDevice(HSWDEVICE);

crates/punktfunk-host/src/inject/windows/gamepad_windows.rs

@@ -12,18 +12,18 @@
 //! parses the `SET_STATE` packet into the shared section, and [`GamepadManager::pump_rumble`] relays
 //! level changes to the client (the universal 0xCA plane), mirroring the Linux `EV_FF` read path.
 
-use super::gamepad_raii::PadChannel;
+use super::gamepad_raii::{sw_create_cb, PadChannel, SwCreateCtx};
 use crate::gamestream::gamepad::{GamepadEvent, MAX_PADS};
 use crate::inject::pad_gate::PadGate;
 use anyhow::{anyhow, Result};
 use std::ffi::c_void;
 use std::time::{Duration, Instant};
-use windows::core::{w, GUID, HRESULT, PCWSTR};
+use windows::core::{w, GUID, PCWSTR};
 use windows::Win32::Devices::Enumeration::Pnp::{
     SwDeviceClose, SwDeviceCreate, HSWDEVICE, SW_DEVICE_CREATE_INFO,
 };
-use windows::Win32::Foundation::{CloseHandle, E_FAIL, HANDLE, WAIT_OBJECT_0};
+use windows::Win32::Foundation::{CloseHandle, E_FAIL, WAIT_OBJECT_0};
-use windows::Win32::System::Threading::{CreateEventW, SetEvent, WaitForSingleObject};
+use windows::Win32::System::Threading::{CreateEventW, WaitForSingleObject};
 
 // Shared-section layout — the single source of truth is `pf_driver_proto::gamepad::XusbShm` (offset
 // asserts pin every field; the `pf_xusb` driver maps the same struct). Derive the size/offsets/magic from
@@ -44,49 +44,6 @@ const OFF_RUMBLE: usize = core::mem::offset_of!(XusbShm, rumble_large); // large
 const OFF_DRIVER_PROTO: usize = core::mem::offset_of!(XusbShm, driver_proto);
 const OFF_PAD_INDEX: usize = core::mem::offset_of!(XusbShm, pad_index);
 
-/// Context for the `SwDeviceCreate` completion callback: an event to signal, the HRESULT it reports,
-/// and the PnP instance id PnP assigned (captured for devnode health diagnostics).
-#[repr(C)]
-struct SwCreateCtx {
-    event: HANDLE,
-    result: HRESULT,
-    instance_id: [u16; 128],
-}
-
-/// `SwDeviceCreate` fires this once PnP has enumerated the device; stash the result + wake the creator.
-unsafe extern "system" fn sw_create_cb(
-    _dev: HSWDEVICE,
-    result: HRESULT,
-    ctx: *const c_void,
-    id: PCWSTR,
-) {
-    if !ctx.is_null() {
-        // SAFETY: ctx is the &mut SwCreateCtx the creator passed; it outlives this callback (the
-        // creator blocks on the event). `id` is a NUL-terminated string for the callback's duration.
-        unsafe {
-            let c = ctx as *mut SwCreateCtx;
-            (*c).result = result;
-            if !id.is_null() {
-                for i in 0..(*c).instance_id.len() - 1 {
-                    let ch = *id.0.add(i);
-                    (*c).instance_id[i] = ch;
-                    if ch == 0 {
-                        break;
-                    }
-                }
-            }
-            let _ = SetEvent((*c).event);
-        }
-    }
-}
-
-impl SwCreateCtx {
-    fn instance_id(&self) -> Option<String> {
-        let len = self.instance_id.iter().position(|&c| c == 0)?;
-        (len > 0).then(|| String::from_utf16_lossy(&self.instance_id[..len]))
-    }
-}
-
 /// Spawn the `pf_xusb_<index>` companion devnode (hardware id `pf_xusb`, enumerator `punktfunk`). The
 /// INF (System class) binds our UMDF driver, which registers the XUSB interface. Unlike the HID pads,
 /// no USB compatible-ids are needed — XInput finds the device by the interface GUID, not VID/PID — but