[PATCH v5 04/13] xen/spinlock: add rspin_[un]lock_irq[save|restore]()

[Juergen Gross <jgross@suse.com>]

Instead of special casing rspin_lock_irqsave() and
rspin_unlock_irqrestore() for the console lock, add those functions
to spinlock handling and use them where needed.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
V2:
- new patch
V5:
- avoid MISRA violation (Julien Grall)
- keep wrapper functions (Jan Beulich)
---
 xen/common/spinlock.c      | 18 +++++++++++++++++-
 xen/drivers/char/console.c |  6 ++----
 xen/include/xen/spinlock.h |  9 +++++++++
 3 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/xen/common/spinlock.c b/xen/common/spinlock.c
index 11e13e1259..5ef0ac7f89 100644
--- a/xen/common/spinlock.c
+++ b/xen/common/spinlock.c
@@ -475,15 +475,31 @@ void _rspin_lock(rspinlock_t *lock)
     lock->recurse_cnt++;
 }
 
+unsigned long _rspin_lock_irqsave(rspinlock_t *lock)
+{
+    unsigned long flags;
+
+    local_irq_save(flags);
+    _rspin_lock(lock);
+
+    return flags;
+}
+
 void _rspin_unlock(rspinlock_t *lock)
 {
     if ( likely(--lock->recurse_cnt == 0) )
     {
         lock->recurse_cpu = SPINLOCK_NO_CPU;
-        spin_unlock(lock);
+        _spin_unlock(lock);
     }
 }
 
+void _rspin_unlock_irqrestore(rspinlock_t *lock, unsigned long flags)
+{
+    _rspin_unlock(lock);
+    local_irq_restore(flags);
+}
+
 #ifdef CONFIG_DEBUG_LOCK_PROFILE
 
 struct lock_profile_anc {
diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index eca17b55b4..ccd5f8cc14 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -1161,16 +1161,14 @@ unsigned long console_lock_recursive_irqsave(void)
 {
     unsigned long flags;
 
-    local_irq_save(flags);
-    rspin_lock(&console_lock);
+    rspin_lock_irqsave(&console_lock, flags);
 
     return flags;
 }
 
 void console_unlock_recursive_irqrestore(unsigned long flags)
 {
-    rspin_unlock(&console_lock);
-    local_irq_restore(flags);
+    rspin_unlock_irqrestore(&console_lock, flags);
 }
 
 void console_force_unlock(void)
diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h
index 50f6580f52..afa24c8e29 100644
--- a/xen/include/xen/spinlock.h
+++ b/xen/include/xen/spinlock.h
@@ -272,7 +272,15 @@ static always_inline void spin_lock_if(bool condition, spinlock_t *l)
  */
 bool _rspin_trylock(rspinlock_t *lock);
 void _rspin_lock(rspinlock_t *lock);
+#define rspin_lock_irqsave(l, f)                                \
+    ({                                                          \
+        BUILD_BUG_ON(sizeof(f) != sizeof(unsigned long));       \
+        ((f) = _rspin_lock_irqsave(l));                         \
+        block_lock_speculation();                               \
+    })
+unsigned long _rspin_lock_irqsave(rspinlock_t *lock);
 void _rspin_unlock(rspinlock_t *lock);
+void _rspin_unlock_irqrestore(rspinlock_t *lock, unsigned long flags);
 
 static always_inline void rspin_lock(rspinlock_t *lock)
 {
@@ -282,5 +290,6 @@ static always_inline void rspin_lock(rspinlock_t *lock)
 
 #define rspin_trylock(l)              lock_evaluate_nospec(_rspin_trylock(l))
 #define rspin_unlock(l)               _rspin_unlock(l)
+#define rspin_unlock_irqrestore(l, f) _rspin_unlock_irqrestore(l, f)
 
 #endif /* __SPINLOCK_H__ */
-- 
2.35.3