[ioapi] Split ioremap() out to a separate IOMAP API

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/io.h

@@ -20,8 +20,8 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #include <stdint.h>
 #include <ipxe/api.h>
+#include <ipxe/iomap.h>
 #include <config/ioapi.h>
-#include <ipxe/uaccess.h>
 
 /** Page size */
 #define PAGE_SIZE ( 1 << PAGE_SHIFT )
@@ -196,30 +196,6 @@ static inline __always_inline void * bus_to_virt ( unsigned long bus_addr ) {
 	return phys_to_virt ( bus_to_phys ( bus_addr ) );
 }
 
-/**
- * Map bus address as an I/O address
- *
- * @v bus_addr		Bus address
- * @v len		Length of region
- * @ret io_addr		I/O address
- */
-void * ioremap ( unsigned long bus_addr, size_t len );
-
-/**
- * Unmap I/O address
- *
- * @v io_addr		I/O address
- */
-void iounmap ( volatile const void *io_addr );
-
-/**
- * Convert I/O address to bus address (for debug only)
- *
- * @v io_addr		I/O address
- * @ret bus_addr	Bus address
- */
-unsigned long io_to_bus ( volatile const void *io_addr );
-
 /**
  * Read byte from memory-mapped device
  *

src/include/ipxe/iomap.h

@@ -0,0 +1,78 @@
+#ifndef _IPXE_IOMAP_H
+#define _IPXE_IOMAP_H
+
+/** @file
+ *
+ * iPXE I/O mapping API
+ *
+ * The I/O mapping API provides methods for mapping and unmapping I/O
+ * devices.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <ipxe/api.h>
+#include <config/ioapi.h>
+#include <ipxe/uaccess.h>
+
+/**
+ * Calculate static inline I/O mapping API function name
+ *
+ * @v _prefix		Subsystem prefix
+ * @v _api_func		API function
+ * @ret _subsys_func	Subsystem API function
+ */
+#define IOMAP_INLINE( _subsys, _api_func ) \
+	SINGLE_API_INLINE ( IOMAP_PREFIX_ ## _subsys, _api_func )
+
+/**
+ * Provide an I/O mapping API implementation
+ *
+ * @v _prefix		Subsystem prefix
+ * @v _api_func		API function
+ * @v _func		Implementing function
+ */
+#define PROVIDE_IOMAP( _subsys, _api_func, _func ) \
+	PROVIDE_SINGLE_API ( IOMAP_PREFIX_ ## _subsys, _api_func, _func )
+
+/**
+ * Provide a static inline I/O mapping API implementation
+ *
+ * @v _prefix		Subsystem prefix
+ * @v _api_func		API function
+ */
+#define PROVIDE_IOMAP_INLINE( _subsys, _api_func ) \
+	PROVIDE_SINGLE_API_INLINE ( IOMAP_PREFIX_ ## _subsys, _api_func )
+
+/* Include all architecture-independent I/O API headers */
+#include <ipxe/iomap_virt.h>
+
+/* Include all architecture-dependent I/O API headers */
+#include <bits/iomap.h>
+
+/**
+ * Map bus address as an I/O address
+ *
+ * @v bus_addr		Bus address
+ * @v len		Length of region
+ * @ret io_addr		I/O address
+ */
+void * ioremap ( unsigned long bus_addr, size_t len );
+
+/**
+ * Unmap I/O address
+ *
+ * @v io_addr		I/O address
+ */
+void iounmap ( volatile const void *io_addr );
+
+/**
+ * Convert I/O address to bus address (for debug only)
+ *
+ * @v io_addr		I/O address
+ * @ret bus_addr	Bus address
+ */
+unsigned long io_to_bus ( volatile const void *io_addr );
+
+#endif /* _IPXE_IOMAP_H */

src/include/ipxe/iomap_virt.h

@@ -0,0 +1,33 @@
+#ifndef _IPXE_IOMAP_VIRT_H
+#define _IPXE_IOMAP_VIRT_H
+
+/** @file
+ *
+ * iPXE I/O mapping API using phys_to_virt()
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#ifdef IOMAP_VIRT
+#define IOMAP_PREFIX_virt
+#else
+#define IOMAP_PREFIX_virt __virt_
+#endif
+
+static inline __always_inline void *
+IOMAP_INLINE ( virt, ioremap ) ( unsigned long bus_addr, size_t len __unused ) {
+	return ( bus_addr ? phys_to_virt ( bus_addr ) : NULL );
+}
+
+static inline __always_inline void
+IOMAP_INLINE ( virt, iounmap ) ( volatile const void *io_addr __unused ) {
+	/* Nothing to do */
+}
+
+static inline __always_inline unsigned long
+IOMAP_INLINE ( virt, io_to_bus ) ( volatile const void *io_addr ) {
+	return virt_to_phys ( io_addr );
+}
+
+#endif /* _IPXE_IOMAP_VIRT_H */