[PATCH v2 3/4] media: atomisp: queue: move circbuf types and helpers to queue_comm.h

[Rareș-Mihai Vladu]

The remote queue code only needs the circbuf descriptor and element
layouts plus five small descriptor helpers from the circbuf library.
Move them into ia_css_queue_comm.h and include that header instead of
the circbuf ones.

The descriptor and element layouts are shared with the SP firmware and
are moved unchanged, including their static_asserts.

While at it, drop the OP___assert() NULL checks from the moved helpers,
as every caller passes the address of a local variable, and convert the
moved code to the kernel u8/u32 types and the usual function
declaration style.

Signed-off-by: Rareș-Mihai Vladu <vladurares@xxxxxxxxx>
---
 .../queue/interface/ia_css_queue_comm.h       | 130 +++++++++++++++++-
 .../atomisp/pci/runtime/queue/src/queue.c     |   2 -
 .../pci/runtime/queue/src/queue_access.c      |   1 -
 .../pci/runtime/queue/src/queue_access.h      |   1 -
 .../media/atomisp/pci/sh_css_internal.h       |   2 +-
 5 files changed, 130 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/runtime/queue/interface/ia_css_queue_comm.h b/drivers/staging/media/atomisp/pci/runtime/queue/interface/ia_css_queue_comm.h
index 7cd788e2b16bd..8323347bea6b4 100644
--- a/drivers/staging/media/atomisp/pci/runtime/queue/interface/ia_css_queue_comm.h
+++ b/drivers/staging/media/atomisp/pci/runtime/queue/interface/ia_css_queue_comm.h
@@ -7,8 +7,136 @@
 #ifndef __IA_CSS_QUEUE_COMM_H
 #define __IA_CSS_QUEUE_COMM_H
 
+#include <linux/build_bug.h>
+#include <linux/types.h>
+
 #include "type_support.h"
-#include "ia_css_circbuf.h"
+
+/****************************************************************
+ *
+ * Portable Data structures
+ *
+ ****************************************************************/
+/*
+ * @brief Data structure for the circular descriptor.
+ */
+typedef struct ia_css_circbuf_desc_s ia_css_circbuf_desc_t;
+struct ia_css_circbuf_desc_s {
+	u8 size;	/* the maximum number of elements*/
+	u8 step;   /* number of bytes per element */
+	u8 start;	/* index of the oldest element */
+	u8 end;	/* index at which to write the new element */
+};
+
+#define SIZE_OF_IA_CSS_CIRCBUF_DESC_S_STRUCT	(4 * sizeof(u8))
+
+static_assert(sizeof(struct ia_css_circbuf_desc_s) == SIZE_OF_IA_CSS_CIRCBUF_DESC_S_STRUCT);
+
+/*
+ * @brief Data structure for the circular buffer element.
+ */
+typedef struct ia_css_circbuf_elem_s ia_css_circbuf_elem_t;
+struct ia_css_circbuf_elem_s {
+	u32 val;	/* the value stored in the element */
+};
+
+#define SIZE_OF_IA_CSS_CIRCBUF_ELEM_S_STRUCT	(sizeof(u32))
+
+static_assert(sizeof(struct ia_css_circbuf_elem_s) == SIZE_OF_IA_CSS_CIRCBUF_ELEM_S_STRUCT);
+
+/****************************************************************
+ *
+ * Inline functions.
+ *
+ ****************************************************************/
+/*
+ * @brief Test if the circular buffer is empty.
+ *
+ * @param cb_desc The pointer to the circular buffer descriptor.
+ *
+ * @return
+ *	- true when it is empty.
+ *	- false when it is not empty.
+ */
+static inline bool ia_css_circbuf_desc_is_empty(ia_css_circbuf_desc_t *cb_desc)
+{
+	return (cb_desc->end == cb_desc->start);
+}
+
+/*
+ * @brief Test if the circular buffer descriptor is full.
+ *
+ * @param cb_desc	The pointer to the circular buffer
+ *			descriptor.
+ *
+ * @return
+ *	- true when it is full.
+ *	- false when it is not full.
+ */
+static inline bool ia_css_circbuf_desc_is_full(ia_css_circbuf_desc_t *cb_desc)
+{
+	return ((cb_desc->end + 1) % cb_desc->size) == cb_desc->start;
+}
+
+/*
+ * @brief Get the offset between two positions in the circular buffer
+ * descriptor.
+ * Get the offset from the source position to the terminal position,
+ * along the direction in which the new elements come in.
+ *
+ * @param cb_desc	The pointer to the circular buffer descriptor.
+ * @param src_pos	The source position.
+ * @param dest_pos	The terminal position.
+ *
+ * @return the offset.
+ */
+static inline int ia_css_circbuf_desc_get_offset(ia_css_circbuf_desc_t *cb_desc,
+						 u32 src_pos, u32 dest_pos)
+{
+	int offset;
+
+	offset = (int)(dest_pos - src_pos);
+	offset += (offset < 0) ? cb_desc->size : 0;
+
+	return offset;
+}
+
+/*
+ * @brief Get the number of available elements.
+ *
+ * @param cb_desc The pointer to the circular buffer.
+ *
+ * @return The number of available elements.
+ */
+static inline u32 ia_css_circbuf_desc_get_num_elems(ia_css_circbuf_desc_t *cb_desc)
+{
+	int num;
+
+	num = ia_css_circbuf_desc_get_offset(cb_desc,
+					     cb_desc->start,
+					     cb_desc->end);
+
+	return (u32)num;
+}
+
+/*
+ * @brief Get the number of free elements.
+ *
+ * @param cb_desc The pointer to the circular buffer descriptor.
+ *
+ * @return: The number of free elements.
+ */
+static inline u32 ia_css_circbuf_desc_get_free_elems(ia_css_circbuf_desc_t *cb_desc)
+{
+	u32 num;
+
+	num = ia_css_circbuf_desc_get_offset(cb_desc,
+					     cb_desc->start,
+					     cb_desc->end);
+
+	return (cb_desc->size - num);
+}
+
 /*****************************************************************************
  * Queue Public Data Structures
  *****************************************************************************/
diff --git a/drivers/staging/media/atomisp/pci/runtime/queue/src/queue.c b/drivers/staging/media/atomisp/pci/runtime/queue/src/queue.c
index d3818fe8be364..79a67b3c614eb 100644
--- a/drivers/staging/media/atomisp/pci/runtime/queue/src/queue.c
+++ b/drivers/staging/media/atomisp/pci/runtime/queue/src/queue.c
@@ -6,8 +6,6 @@
 
 #include "ia_css_queue.h"
 #include <math_support.h>
-#include <ia_css_circbuf.h>
-#include <ia_css_circbuf_desc.h>
 #include "queue_access.h"
 
 /*****************************************************************************
diff --git a/drivers/staging/media/atomisp/pci/runtime/queue/src/queue_access.c b/drivers/staging/media/atomisp/pci/runtime/queue/src/queue_access.c
index 2591d157870ce..65835420a13c0 100644
--- a/drivers/staging/media/atomisp/pci/runtime/queue/src/queue_access.c
+++ b/drivers/staging/media/atomisp/pci/runtime/queue/src/queue_access.c
@@ -8,7 +8,6 @@
 
 #include "type_support.h"
 #include "queue_access.h"
-#include "ia_css_circbuf.h"
 #include "sp.h"
 #include "assert_support.h"
 
diff --git a/drivers/staging/media/atomisp/pci/runtime/queue/src/queue_access.h b/drivers/staging/media/atomisp/pci/runtime/queue/src/queue_access.h
index 776c6d6cb1fcc..93dae469cff9a 100644
--- a/drivers/staging/media/atomisp/pci/runtime/queue/src/queue_access.h
+++ b/drivers/staging/media/atomisp/pci/runtime/queue/src/queue_access.h
@@ -11,7 +11,6 @@
 
 #include <type_support.h>
 #include <ia_css_queue_comm.h>
-#include <ia_css_circbuf.h>
 
 #define QUEUE_IGNORE_START_FLAG	0x0001
 #define QUEUE_IGNORE_END_FLAG	0x0002
diff --git a/drivers/staging/media/atomisp/pci/sh_css_internal.h b/drivers/staging/media/atomisp/pci/sh_css_internal.h
index ec68c16d42722..f08f918b361c4 100644
--- a/drivers/staging/media/atomisp/pci/sh_css_internal.h
+++ b/drivers/staging/media/atomisp/pci/sh_css_internal.h
@@ -29,7 +29,7 @@
 #include "sh_css_defs.h"
 #include "sh_css_uds.h"
 #include "dma.h"	/* N_DMA_CHANNEL_ID */
-#include "ia_css_circbuf_comm.h" /* Circular buffer */
+#include "ia_css_queue_comm.h"
 #include "ia_css_frame_comm.h"
 #include "ia_css_3a.h"
 #include "ia_css_dvs.h"
-- 
2.43.0