Module spinlock 

Generic spinlock with configurable guard behaviour.

Choosing a guardian

SpinLock<T>                  →  SpinLock<T, IrqDisabled>   (default)
SpinLock<T, IrqDisabled>     →  saves RFLAGS + clears IF (equiv. spin_lock_irqsave)
SpinLock<T, PreemptDisabled> →  disables preemption only, IRQs untouched

Use IrqDisabled (the default) for:

• Data shared across CPUs (heap, VFS, IPC queues, network rings, …)
• Any data touched from interrupt handlers

Use PreemptDisabled for:

• Per-CPU data never accessed from interrupt handlers (scheduler run-queues, per-CPU frame caches, statistics counters …)

All call sites that use SpinLock<T> without a type argument continue to compile unchanged : IrqDisabled is the default guardian.

Debug helpers

debug_set_watch_lock_addr / debug_clear_watch_lock_addr emit a serial trace on every drop of a specific lock instance : useful when hunting deadlocks.

Structs

SpinLock

A spinlock parameterised by a Guardian.

SpinLockGuard

RAII guard that holds the lock and carries the guardian state.

Constants

DEBUG_TRACE_WATCH_SLOTS 🔒

Maximum number of locks that can be traced simultaneously via E9 port.

Statics

DEBUG_TRACE_WATCH_ADDRS 🔒

Fixed-size array of watched lock addresses for E9 trace. Each slot emits a unique ASCII tag (‘A’..‘H’) on acquire/release.

DEBUG_WATCH_LOCK_ADDR 🔒

Functions

debug_clear_trace_slot

Clear a specific trace slot by index.

debug_clear_watch_lock_addr

Clear the watched lock address.

debug_set_trace_buddy_addr

Legacy alias: register the first available trace slot.

debug_set_trace_lock_addr

Register a lock address for E9 trace. Returns the slot index (0..7), or None if all slots are in use.

debug_set_trace_slab_addr

Legacy alias: register the first available trace slot.

debug_set_watch_lock_addr

Register a lock address to trace on every drop (serial console output).

emit_trace_e9 🔒

Emit an E9 byte for each matching trace slot (acquire = uppercase, release = lowercase).