Type-safe ioport callbacks

The current ioport callbacks are not type-safe, in that they accept an "opaque"
pointer as an argument whose type must match the argument to the registration
function; this is not checked by the compiler.

This patch adds an alternative that is type-safe.  Instead of an opaque
argument, both registation and the callback use a new IOPort type.  The
callback then uses container_of() to access its main structures.

Currently the old and new methods exist side by side; once the old way is gone,
we can also save a bunch of memory since the new method requires one pointer
per ioport instead of 6.

Acked-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/iorange.h b/iorange.h
new file mode 100644
index 0000000000..97831683f0
--- /dev/null
+++ b/iorange.h
@@ -0,0 +1,30 @@
+#ifndef IORANGE_H
+#define IORANGE_H
+
+#include <stdint.h>
+
+typedef struct IORange IORange;
+typedef struct IORangeOps IORangeOps;
+
+struct IORangeOps {
+    void (*read)(IORange *iorange, uint64_t offset, unsigned width,
+                 uint64_t *data);
+    void (*write)(IORange *iorange, uint64_t offset, unsigned width,
+                  uint64_t data);
+};
+
+struct IORange {
+    const IORangeOps *ops;
+    uint64_t base;
+    uint64_t len;
+};
+
+static inline void iorange_init(IORange *iorange, const IORangeOps *ops,
+                                uint64_t base, uint64_t len)
+{
+    iorange->ops = ops;
+    iorange->base = base;
+    iorange->len = len;
+}
+
+#endif