[PATCH v6 1/7] kfifo: provide noirqsave variants of spinlocked in and out helpers

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>

Provide variants of spinlocked kfifo_in() and kfifo_out() routines which
don't disable interrupts.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
Acked-by: Stefani Seibold <stefani@xxxxxxxxxxx>
---
 include/linux/kfifo.h | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/include/linux/kfifo.h b/include/linux/kfifo.h
index fc4b0b10210f..123c200ed7cb 100644
--- a/include/linux/kfifo.h
+++ b/include/linux/kfifo.h
@@ -517,6 +517,26 @@ __kfifo_uint_must_check_helper( \
 	__ret; \
 })
 
+/**
+ * kfifo_in_spinlocked_noirqsave - put data into fifo using a spinlock for
+ * locking, don't disable interrupts
+ * @fifo: address of the fifo to be used
+ * @buf: the data to be added
+ * @n: number of elements to be added
+ * @lock: pointer to the spinlock to use for locking
+ *
+ * This is a variant of kfifo_in_spinlocked() but uses spin_lock/unlock()
+ * for locking and doesn't disable interrupts.
+ */
+#define kfifo_in_spinlocked_noirqsave(fifo, buf, n, lock) \
+({ \
+	unsigned int __ret; \
+	spin_lock(lock); \
+	__ret = kfifo_in(fifo, buf, n); \
+	spin_unlock(lock); \
+	__ret; \
+})
+
 /* alias for kfifo_in_spinlocked, will be removed in a future release */
 #define kfifo_in_locked(fifo, buf, n, lock) \
 		kfifo_in_spinlocked(fifo, buf, n, lock)
@@ -569,6 +589,28 @@ __kfifo_uint_must_check_helper( \
 }) \
 )
 
+/**
+ * kfifo_out_spinlocked_noirqsave - get data from the fifo using a spinlock
+ * for locking, don't disable interrupts
+ * @fifo: address of the fifo to be used
+ * @buf: pointer to the storage buffer
+ * @n: max. number of elements to get
+ * @lock: pointer to the spinlock to use for locking
+ *
+ * This is a variant of kfifo_out_spinlocked() which uses spin_lock/unlock()
+ * for locking and doesn't disable interrupts.
+ */
+#define kfifo_out_spinlocked_noirqsave(fifo, buf, n, lock) \
+__kfifo_uint_must_check_helper( \
+({ \
+	unsigned int __ret; \
+	spin_lock(lock); \
+	__ret = kfifo_out(fifo, buf, n); \
+	spin_unlock(lock); \
+	__ret; \
+}) \
+)
+
 /* alias for kfifo_out_spinlocked, will be removed in a future release */
 #define kfifo_out_locked(fifo, buf, n, lock) \
 		kfifo_out_spinlocked(fifo, buf, n, lock)
-- 
2.23.0