nommu: fix shared mmap after truncate shrinkage problems

[karo-tx-linux.git] / include / linux / kfifo.h

diff --git a/include/linux/kfifo.h b/include/linux/kfifo.h
index 6fb495ea956aa6f11377cdc1277e1aee857fe353..6f6c5f300af6f9bb1485c59960832eca7d8d0983 100644 (file)
--- a/include/linux/kfifo.h
+++ b/include/linux/kfifo.h
@@ -67,7 +67,7 @@ struct kfifo {
 /**
  * DECLARE_KFIFO - macro to declare a kfifo and the associated buffer
  * @name: name of the declared kfifo datatype
- * @size: size of the fifo buffer
+ * @size: size of the fifo buffer. Must be a power of two.
  *
  * Note1: the macro can be used inside struct or union declaration
  * Note2: the macro creates two objects:
@@ -91,7 +91,7 @@ union { \
 /**
  * DEFINE_KFIFO - macro to define and initialize a kfifo
  * @name: name of the declared kfifo datatype
- * @size: size of the fifo buffer
+ * @size: size of the fifo buffer. Must be a power of two.
  *
  * Note1: the macro can be used for global and local kfifo data type variables
  * Note2: the macro creates two objects:
@@ -113,6 +113,19 @@ extern unsigned int kfifo_in(struct kfifo *fifo,
                                const void *from, unsigned int len);
 extern __must_check unsigned int kfifo_out(struct kfifo *fifo,
                                void *to, unsigned int len);
+extern __must_check unsigned int kfifo_out_peek(struct kfifo *fifo,
+                               void *to, unsigned int len, unsigned offset);
+
+/**
+ * kfifo_initialized - Check if kfifo is initialized.
+ * @fifo: fifo to check
+ * Return %true if FIFO is initialized, otherwise %false.
+ * Assumes the fifo was 0 before.
+ */
+static inline bool kfifo_initialized(struct kfifo *fifo)
+{
+       return fifo->buffer != 0;
+}
 
 /**
  * kfifo_reset - removes the entire FIFO contents
@@ -235,11 +248,11 @@ static inline __must_check unsigned int kfifo_out_locked(struct kfifo *fifo,
 
 extern void kfifo_skip(struct kfifo *fifo, unsigned int len);
 
-extern __must_check unsigned int kfifo_from_user(struct kfifo *fifo,
-       const void __user *from, unsigned int n);
+extern __must_check int kfifo_from_user(struct kfifo *fifo,
+       const void __user *from, unsigned int n, unsigned *lenout);
 
-extern __must_check unsigned int kfifo_to_user(struct kfifo *fifo,
-       void __user *to, unsigned int n);
+extern __must_check int kfifo_to_user(struct kfifo *fifo,
+       void __user *to, unsigned int n, unsigned *lenout);
 
 /*
  * __kfifo_add_out internal helper function for updating the out offset