Device Framework support.

Change-Id: I133f58df309c7fc3a7faa261699eba66a6bae4be
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/98
Tested-by: Jenkins Server
Reviewed-by: Thi N. Tran <thi@us.ibm.com>
Reviewed-by: Andrew J. Geissler <andrewg@us.ibm.com>

1 files changed, 93 insertions, 0 deletions

diff --git a/src/usr/devicefw/assoccontain.H b/src/usr/devicefw/assoccontain.H
new file mode 100644
index 000000000..9786168e0
--- /dev/null
+++ b/src/usr/devicefw/assoccontain.H
@@ -0,0 +1,93 @@
+/** @file assoccontain.H
+ *  @brief Provides a memory pool container for allocating blocks of
+ *         associations for the device driver framework.
+ *
+ *  This class exists because storing the information in a normal map or
+ *  vector would be exceptionally big for the expected sparseness of the
+ *  device driver associations.
+ */
+
+#ifndef __DEVICEFW_ASSOCCONTAIN_H
+#define __DEVICEFW_ASSOCCONTAIN_H
+
+#include <stdint.h>
+#include <builtins.h>
+
+namespace DeviceFW
+{
+    /** @struct AssociationData
+     *  @brief  Data about a particular association.
+     *
+     *  Typically this is a offset (pointer) to another association and an
+     *  optional flag for the associatior to use.  This allows a user to
+     *  construct a light-weight multi-dimensional sparse array.
+     *
+     *  The purpose of the flag field is left to the user.
+     */
+    struct AssociationData
+    {
+        bool    flag:1;
+        size_t  offset:15;
+        
+        AssociationData() : flag(false), offset(0) { };
+
+        AssociationData(bool i_flag, size_t i_off) 
+            : flag(i_flag), offset(i_off) { };
+
+    } PACKED;
+    
+    /** @class AssociationContainer
+     *  @brief The memory pool container of AssociationData blocks.
+     *
+     *  The typical usage of this will be to create a multi-dimensional sparse
+     *  associative array (map).  The first block allocated will be the first
+     *  dimension of the array.  Each AssociationData entry in the block is the
+     *  offset of the block containing the AssociationData for the next 
+     *  dimension.  At the lowest level this offset might be used as an offset
+     *  into another container, such as an std::vector.
+     */
+    class AssociationContainer
+    {
+        public:
+            /**
+             * @brief Constructor for AssociationContainer.
+             *
+             * Initializes internal members to clean values.
+             */
+            AssociationContainer();
+
+            /**
+             * @brief Destructor for AssociationContainer.
+             *
+             * Releases memory associated with container.  After this call
+             * all pointers previously obtained through operator[] are invalid.
+             */
+            ~AssociationContainer();
+                
+            /**
+             * @brief Look up a particular association entry by offset.
+             * @return A pointer to the requested association block.
+             *
+             * @note Will return a NULL pointer if an invalid offset is given.
+             */
+            AssociationData* operator[](size_t) const;
+
+            /**
+             * @brief Allocate a new block into the pool.
+             * @return A offset to the newly allocated block.
+             *
+             * The blocks allocated will all be erased to 0's.
+             *
+             * @note This function can change the pointers previously
+             *       returned by the operator[].  Treat this function
+             *       as though all previous pointers are invalidated.
+             */
+            size_t allocate(size_t);
+
+        private:
+            AssociationData*    iv_data;
+            size_t              iv_size;
+    };
+};
+
+#endif