diff mbox

[v7,3/6] FIFO: Add a FIFO32 implementation

Message ID ad9f984f4a6e966ca94742cbe8731e0f2a13cecb.1459606813.git.jcd@tribudubois.net
State New
Headers show

Commit Message

Jean-Christophe DUBOIS April 2, 2016, 2:29 p.m. UTC
This one is build on top of the existing FIFO8

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
---

Changes since V1:
 * None 
 
Changes since V2:
 * Added copyright
 * define Fifo32 as a struct containing Fifo8
 * remove fifo32_pop_buf()

Changes since V3: 
 * Added comment on unsupported fifo32_pop_buf()
 
Changes since V4:
 * None

Changes since V5:
 * None

Changes since V6:
 * None

 include/qemu/fifo32.h | 191 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 191 insertions(+)
 create mode 100644 include/qemu/fifo32.h
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Patch

diff --git a/include/qemu/fifo32.h b/include/qemu/fifo32.h
new file mode 100644
index 0000000..2e5a0cc
--- /dev/null
+++ b/include/qemu/fifo32.h
@@ -0,0 +1,191 @@ 
+/*
+ * Generic FIFO32 component, based on FIFO8.
+ *
+ * Copyright (c) 2016 Jean-Christophe Dubois
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef FIFO32_H
+#define FIFO32_H
+
+#include "qemu/osdep.h"
+#include "qemu/fifo8.h"
+
+typedef struct {
+    Fifo8 fifo;
+} Fifo32;
+
+/**
+ * fifo32_create:
+ * @fifo: struct Fifo32 to initialise with new FIFO
+ * @capacity: capacity of the newly created FIFO expressed in 32 bit words
+ *
+ * Create a FIFO of the specified size. Clients should call fifo32_destroy()
+ * when finished using the fifo. The FIFO is initially empty.
+ */
+
+static inline void fifo32_create(Fifo32 *fifo, uint32_t capacity)
+{
+    fifo8_create(&fifo->fifo, capacity * sizeof(uint32_t));
+}
+
+/**
+ * fifo32_destroy:
+ * @fifo: FIFO to cleanup
+ *
+ * Cleanup a FIFO created with fifo32_create(). Frees memory created for FIFO
+ * storage. The FIFO is no longer usable after this has been called.
+ */
+
+static inline void fifo32_destroy(Fifo32 *fifo)
+{
+    fifo8_destroy(&fifo->fifo);
+}
+
+/**
+ * fifo32_num_free:
+ * @fifo: FIFO to check
+ *
+ * Return the number of free uint32_t slots in the FIFO.
+ *
+ * Returns: Number of free 32 bit words.
+ */
+
+static inline uint32_t fifo32_num_free(Fifo32 *fifo)
+{
+    return DIV_ROUND_UP(fifo8_num_free(&fifo->fifo), sizeof(uint32_t));
+}
+
+/**
+ * fifo32_num_used:
+ * @fifo: FIFO to check
+ *
+ * Return the number of used uint32_t slots in the FIFO.
+ *
+ * Returns: Number of used 32 bit words.
+ */
+
+static inline uint32_t fifo32_num_used(Fifo32 *fifo)
+{
+    return DIV_ROUND_UP(fifo8_num_used(&fifo->fifo), sizeof(uint32_t));
+}
+
+/**
+ * fifo32_push:
+ * @fifo: FIFO to push to
+ * @data: 32 bits data word to push
+ *
+ * Push a 32 bits data word to the FIFO. Behaviour is undefined if the FIFO
+ * is full. Clients are responsible for checking for fullness using
+ * fifo32_is_full().
+ */
+
+static inline void fifo32_push(Fifo32 *fifo, uint32_t data)
+{
+    int i;
+
+    for (i = 0; i < sizeof(data); i++) {
+        fifo8_push(&fifo->fifo, data & 0xff);
+        data >>= 8;
+    }
+}
+
+/**
+ * fifo32_push_all:
+ * @fifo: FIFO to push to
+ * @data: data to push
+ * @size: number of 32 bit words to push
+ *
+ * Push a 32 bit word array to the FIFO. Behaviour is undefined if the FIFO
+ * is full. Clients are responsible for checking the space left in the FIFO
+ * using fifo32_num_free().
+ */
+
+static inline void fifo32_push_all(Fifo32 *fifo, const uint32_t *data,
+                                   uint32_t num)
+{
+    int i;
+
+    for (i = 0; i < num; i++) {
+        fifo32_push(fifo, data[i]);
+    }
+}
+
+/**
+ * fifo32_pop:
+ * @fifo: fifo to pop from
+ *
+ * Pop a 32 bits data word from the FIFO. Behaviour is undefined if the FIFO
+ * is empty. Clients are responsible for checking for emptiness using
+ * fifo32_is_empty().
+ *
+ * Returns: The popped 32 bits data word.
+ */
+
+static inline uint32_t fifo32_pop(Fifo32 *fifo)
+{
+    uint32_t ret = 0;
+    int i;
+
+    for (i = 0; i < sizeof(uint32_t); i++) {
+        ret |= (fifo8_pop(&fifo->fifo) << (i * 8));
+    }
+
+    return ret;
+}
+
+/**
+ * There is no fifo32_pop_buf() because the data is not stored in the buffer
+ * as a set of native-order words.
+ */
+
+/**
+ * fifo32_reset:
+ * @fifo: FIFO to reset
+ *
+ * Reset a FIFO. All data is discarded and the FIFO is emptied.
+ */
+
+static inline void fifo32_reset(Fifo32 *fifo)
+{
+    fifo8_reset(&fifo->fifo);
+}
+
+/**
+ * fifo32_is_empty:
+ * @fifo: FIFO to check
+ *
+ * Check if a FIFO is empty.
+ *
+ * Returns: True if the fifo is empty, false otherwise.
+ */
+
+static inline bool fifo32_is_empty(Fifo32 *fifo)
+{
+    return fifo8_is_empty(&fifo->fifo);
+}
+
+/**
+ * fifo32_is_full:
+ * @fifo: FIFO to check
+ *
+ * Check if a FIFO is full.
+ *
+ * Returns: True if the fifo is full, false otherwise.
+ */
+
+static inline bool fifo32_is_full(Fifo32 *fifo)
+{
+    return fifo8_num_free(&fifo->fifo) < sizeof(uint32_t);
+}
+
+#define VMSTATE_FIFO32(_field, _state) VMSTATE_FIFO8(_field.fifo, _state)
+
+#endif /* FIFO32_H */