genirq: Provide conditional lock guards

The interrupt core code has an ever repeating pattern:

    unsigned long flags;
    struct irq_desc *desc = irq_get_desc_[bus]lock(irq, &flags, mode);

    if (!desc)
       return -EINVAL;
    ....
    irq_put_desc_[bus]unlock(desc, flags);

That requires gotos in failure paths and just creates visual clutter.

Provide lock guards, which allow to simplify the code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20250429065420.061659985@linutronix.de

diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index b0290849c3956bcadebc10340837585eb38095d1..44d3a67ec191f6e68956e12753196bbb3364d4c8 100644 (file)
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -141,6 +141,10 @@ extern int irq_setup_affinity(struct irq_desc *desc);
 static inline int irq_setup_affinity(struct irq_desc *desc) { return 0; }
 #endif
 
+
+#define for_each_action_of_desc(desc, act)                     \
+       for (act = desc->action; act; act = act->next)
+
 /* Inline functions for support of irq chips on slow busses */
 static inline void chip_bus_lock(struct irq_desc *desc)
 {
@@ -160,14 +164,33 @@ static inline void chip_bus_sync_unlock(struct irq_desc *desc)
 #define IRQ_GET_DESC_CHECK_GLOBAL      (_IRQ_DESC_CHECK)
 #define IRQ_GET_DESC_CHECK_PERCPU      (_IRQ_DESC_CHECK | _IRQ_DESC_PERCPU)
 
-#define for_each_action_of_desc(desc, act)                     \
-       for (act = desc->action; act; act = act->next)
-
-struct irq_desc *
-__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
-                   unsigned int check);
+struct irq_desc *__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
+                                    unsigned int check);
 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus);
 
+__DEFINE_CLASS_IS_CONDITIONAL(irqdesc_lock, true);
+__DEFINE_UNLOCK_GUARD(irqdesc_lock, struct irq_desc,
+                     __irq_put_desc_unlock(_T->lock, _T->flags, _T->bus),
+                     unsigned long flags; bool bus);
+
+static inline class_irqdesc_lock_t class_irqdesc_lock_constructor(unsigned int irq, bool bus,
+                                                                 unsigned int check)
+{
+       class_irqdesc_lock_t _t = {
+               .bus    = bus,
+               .lock   = __irq_get_desc_lock(irq, &_t.flags, bus, check),
+       };
+       return _t;
+}
+
+#define scoped_irqdesc_get_and_lock(_irq, _check)              \
+       scoped_guard(irqdesc_lock, _irq, false, _check)
+
+#define scoped_irqdesc_get_and_buslock(_irq, _check)           \
+       scoped_guard(irqdesc_lock, _irq, true, _check)
+
+#define scoped_irqdesc         ((struct irq_desc *)(__guard_ptr(irqdesc_lock)(&scope)))
+
 static inline struct irq_desc *
 irq_get_desc_buslock(unsigned int irq, unsigned long *flags, unsigned int check)
 {