ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/lib/refcount.c b/marvell/linux/lib/refcount.c
new file mode 100644
index 0000000..ebac8b7
--- /dev/null
+++ b/marvell/linux/lib/refcount.c
@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Out-of-line refcount functions.
+ */
+
+#include <linux/mutex.h>
+#include <linux/refcount.h>
+#include <linux/spinlock.h>
+#include <linux/bug.h>
+
+#define REFCOUNT_WARN(str) WARN_ONCE(1, "refcount_t: " str ".\n")
+
+void refcount_warn_saturate(refcount_t *r, enum refcount_saturation_type t)
+{
+ refcount_set(r, REFCOUNT_SATURATED);
+
+ switch (t) {
+ case REFCOUNT_ADD_NOT_ZERO_OVF:
+ REFCOUNT_WARN("saturated; leaking memory");
+ break;
+ case REFCOUNT_ADD_OVF:
+ REFCOUNT_WARN("saturated; leaking memory");
+ break;
+ case REFCOUNT_ADD_UAF:
+ REFCOUNT_WARN("addition on 0; use-after-free");
+ break;
+ case REFCOUNT_SUB_UAF:
+ REFCOUNT_WARN("underflow; use-after-free");
+ break;
+ case REFCOUNT_DEC_LEAK:
+ REFCOUNT_WARN("decrement hit 0; leaking memory");
+ break;
+ default:
+ REFCOUNT_WARN("unknown saturation event!?");
+ }
+}
+EXPORT_SYMBOL(refcount_warn_saturate);
+
+/**
+ * refcount_dec_if_one - decrement a refcount if it is 1
+ * @r: the refcount
+ *
+ * No atomic_t counterpart, it attempts a 1 -> 0 transition and returns the
+ * success thereof.
+ *
+ * Like all decrement operations, it provides release memory order and provides
+ * a control dependency.
+ *
+ * It can be used like a try-delete operator; this explicit case is provided
+ * and not cmpxchg in generic, because that would allow implementing unsafe
+ * operations.
+ *
+ * Return: true if the resulting refcount is 0, false otherwise
+ */
+bool refcount_dec_if_one(refcount_t *r)
+{
+ int val = 1;
+
+ return atomic_try_cmpxchg_release(&r->refs, &val, 0);
+}
+EXPORT_SYMBOL(refcount_dec_if_one);
+
+/**
+ * refcount_dec_not_one - decrement a refcount if it is not 1
+ * @r: the refcount
+ *
+ * No atomic_t counterpart, it decrements unless the value is 1, in which case
+ * it will return false.
+ *
+ * Was often done like: atomic_add_unless(&var, -1, 1)
+ *
+ * Return: true if the decrement operation was successful, false otherwise
+ */
+bool refcount_dec_not_one(refcount_t *r)
+{
+ unsigned int new, val = atomic_read(&r->refs);
+
+ do {
+ if (unlikely(val == REFCOUNT_SATURATED))
+ return true;
+
+ if (val == 1)
+ return false;
+
+ new = val - 1;
+ if (new > val) {
+ WARN_ONCE(new > val, "refcount_t: underflow; use-after-free.\n");
+ return true;
+ }
+
+ } while (!atomic_try_cmpxchg_release(&r->refs, &val, new));
+
+ return true;
+}
+EXPORT_SYMBOL(refcount_dec_not_one);
+
+/**
+ * refcount_dec_and_mutex_lock - return holding mutex if able to decrement
+ * refcount to 0
+ * @r: the refcount
+ * @lock: the mutex to be locked
+ *
+ * Similar to atomic_dec_and_mutex_lock(), it will WARN on underflow and fail
+ * to decrement when saturated at REFCOUNT_SATURATED.
+ *
+ * Provides release memory ordering, such that prior loads and stores are done
+ * before, and provides a control dependency such that free() must come after.
+ * See the comment on top.
+ *
+ * Return: true and hold mutex if able to decrement refcount to 0, false
+ * otherwise
+ */
+bool refcount_dec_and_mutex_lock(refcount_t *r, struct mutex *lock)
+{
+ if (refcount_dec_not_one(r))
+ return false;
+
+ mutex_lock(lock);
+ if (!refcount_dec_and_test(r)) {
+ mutex_unlock(lock);
+ return false;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL(refcount_dec_and_mutex_lock);
+
+/**
+ * refcount_dec_and_lock - return holding spinlock if able to decrement
+ * refcount to 0
+ * @r: the refcount
+ * @lock: the spinlock to be locked
+ *
+ * Similar to atomic_dec_and_lock(), it will WARN on underflow and fail to
+ * decrement when saturated at REFCOUNT_SATURATED.
+ *
+ * Provides release memory ordering, such that prior loads and stores are done
+ * before, and provides a control dependency such that free() must come after.
+ * See the comment on top.
+ *
+ * Return: true and hold spinlock if able to decrement refcount to 0, false
+ * otherwise
+ */
+bool refcount_dec_and_lock(refcount_t *r, spinlock_t *lock)
+{
+ if (refcount_dec_not_one(r))
+ return false;
+
+ spin_lock(lock);
+ if (!refcount_dec_and_test(r)) {
+ spin_unlock(lock);
+ return false;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL(refcount_dec_and_lock);
+
+/**
+ * refcount_dec_and_lock_irqsave - return holding spinlock with disabled
+ * interrupts if able to decrement refcount to 0
+ * @r: the refcount
+ * @lock: the spinlock to be locked
+ * @flags: saved IRQ-flags if the is acquired
+ *
+ * Same as refcount_dec_and_lock() above except that the spinlock is acquired
+ * with disabled interupts.
+ *
+ * Return: true and hold spinlock if able to decrement refcount to 0, false
+ * otherwise
+ */
+bool refcount_dec_and_lock_irqsave(refcount_t *r, spinlock_t *lock,
+ unsigned long *flags)
+{
+ if (refcount_dec_not_one(r))
+ return false;
+
+ spin_lock_irqsave(lock, *flags);
+ if (!refcount_dec_and_test(r)) {
+ spin_unlock_irqrestore(lock, *flags);
+ return false;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL(refcount_dec_and_lock_irqsave);