Release 1.0

[palacios.git] / geekos / include / geekos / blockdev.h

diff --git a/geekos/include/geekos/blockdev.h b/geekos/include/geekos/blockdev.h
new file mode 100644 (file)
index 0000000..a099da8
--- /dev/null
+++ b/geekos/include/geekos/blockdev.h
@@ -0,0 +1,137 @@
+/*
+ * Block devices
+ * Copyright (c) 2003 David H. Hovemeyer <daveho@cs.umd.edu>
+ * Copyright (c) 2003, Jeffrey K. Hollingsworth <hollings@cs.umd.edu>
+ * $Revision: 1.1 $
+ * 
+ * This is free software.  You are permitted to use,
+ * redistribute, and modify it as specified in the file "COPYING".
+ */
+
+#ifndef GEEKOS_BLOCKDEV_H
+#define GEEKOS_BLOCKDEV_H
+
+#include <geekos/ktypes.h>
+#include <geekos/kthread.h>
+#include <geekos/list.h>
+#include <geekos/fileio.h>
+
+#ifdef GEEKOS
+
+/*
+ * Type of block device request.
+ */
+enum Request_Type {
+    BLOCK_READ, BLOCK_WRITE
+};
+
+/*
+ * State of a block I/O request.
+ */
+enum Request_State {
+    PENDING, COMPLETED, ERROR
+};
+
+struct Block_Request;
+
+/*
+ * List of block I/O requests.
+ */
+DEFINE_LIST(Block_Request_List, Block_Request);
+
+/*
+ * An I/O request for a block device.
+ */
+struct Block_Request {
+    struct Block_Device *dev;
+    enum Request_Type type;
+    int blockNum;
+    void *buf;
+    volatile enum Request_State state;
+    volatile int errorCode;
+    struct Thread_Queue waitQueue;
+
+    DEFINE_LINK(Block_Request_List, Block_Request);
+};
+
+IMPLEMENT_LIST(Block_Request_List, Block_Request);
+
+struct Block_Device;
+struct Block_Device_Ops;
+
+/*
+ * A block device.
+ */
+struct Block_Device {
+    char name[BLOCKDEV_MAX_NAME_LEN];
+    struct Block_Device_Ops *ops;
+    int unit;
+    bool inUse;
+    void *driverData;
+    struct Thread_Queue *waitQueue;
+    struct Block_Request_List *requestQueue;
+
+    DEFINE_LINK(Block_Device_List, Block_Device);
+};
+
+/*
+ * Operations that may be requested on block devices.
+ */
+struct Block_Device_Ops {
+    int (*Open)(struct Block_Device *dev);
+    int (*Close)(struct Block_Device *dev);
+    int (*Get_Num_Blocks)(struct Block_Device *dev);
+};
+
+/*
+ * Low level block device API.
+ * Only block device drivers need to use these functions.
+ */
+int Register_Block_Device(const char *name, struct Block_Device_Ops *ops,
+    int unit, void *driverData, struct Thread_Queue *waitQueue,
+    struct Block_Request_List *requestQueue);
+int Open_Block_Device(const char *name, struct Block_Device **pDev);
+int Close_Block_Device(struct Block_Device *dev);
+struct Block_Request *Create_Request(struct Block_Device *dev, enum Request_Type type,
+    int blockNum, void *buf);
+void Post_Request_And_Wait(struct Block_Request *request);
+struct Block_Request *Dequeue_Request(struct Block_Request_List *requestQueue,
+    struct Thread_Queue *waitQueue);
+void Notify_Request_Completion(struct Block_Request *request, enum Request_State state, int errorCode);
+
+/*
+ * High level block device API.
+ * For use by filesystem and disk paging code.
+ */
+int Block_Read(struct Block_Device *dev, int blockNum, void *buf);
+int Block_Write(struct Block_Device *dev, int blockNum, void *buf);
+int Get_Num_Blocks(struct Block_Device *dev);
+
+/*
+ * Misc. routines
+ */
+
+/*
+ * Round offset up to nearest sector.
+ */
+static __inline__ ulong_t Round_Up_To_Block(ulong_t offset)
+{
+    return (offset % SECTOR_SIZE) == 0
+       ? offset
+       : offset + (SECTOR_SIZE - (offset % SECTOR_SIZE));
+}
+
+/*
+ * Round offset down to nearest sector.
+ */
+static __inline__ ulong_t Round_Down_To_Block(ulong_t offset)
+{
+    return (offset % SECTOR_SIZE) == 0
+       ? offset
+       : offset - (offset % SECTOR_SIZE);
+}
+
+#endif /* GEEKOS */
+
+#endif
+