[SPARC32/64]: Expand ioctl size field in backwards-compatible way.

include/asm-sparc/ioctl.h

@@ -2,23 +2,35 @@
 #ifndef _SPARC_IOCTL_H
 #define _SPARC_IOCTL_H
 
+/*
+ * Our DIR and SIZE overlap in order to simulteneously provide
+ * a non-zero _IOC_NONE (for binary compatibility) and
+ * 14 bits of size as on i386. Here's the layout:
+ *
+ *   0xE0000000   DIR
+ *   0x80000000     DIR = WRITE
+ *   0x40000000     DIR = READ
+ *   0x20000000     DIR = NONE
+ *   0x3FFF0000   SIZE (overlaps NONE bit)
+ *   0x0000FF00   TYPE
+ *   0x000000FF   NR (CMD)
+ */
+
 #define _IOC_NRBITS      8
 #define _IOC_TYPEBITS    8
-#define _IOC_SIZEBITS    8
-#define _IOC_RESVBITS    5
+#define _IOC_SIZEBITS   13	/* Actually 14, see below. */
 #define _IOC_DIRBITS     3
 
 #define _IOC_NRMASK      ((1 << _IOC_NRBITS)-1)
 #define _IOC_TYPEMASK    ((1 << _IOC_TYPEBITS)-1)
-#define _IOC_RESVMASK    ((1 << _IOC_RESVBITS)-1)
 #define _IOC_SIZEMASK    ((1 << _IOC_SIZEBITS)-1)
+#define _IOC_XSIZEMASK   ((1 << (_IOC_SIZEBITS+1))-1)
 #define _IOC_DIRMASK     ((1 << _IOC_DIRBITS)-1)
 
 #define _IOC_NRSHIFT     0
 #define _IOC_TYPESHIFT   (_IOC_NRSHIFT + _IOC_NRBITS)
 #define _IOC_SIZESHIFT   (_IOC_TYPESHIFT + _IOC_TYPEBITS)
-#define _IOC_RESVSHIFT   (_IOC_SIZESHIFT + _IOC_SIZEBITS)
-#define _IOC_DIRSHIFT    (_IOC_RESVSHIFT + _IOC_RESVBITS)
+#define _IOC_DIRSHIFT    (_IOC_SIZESHIFT + _IOC_SIZEBITS)
 
 #define _IOC_NONE        1U
 #define _IOC_READ        2U
@@ -35,17 +47,20 @@
 #define _IOW(type,nr,size)  _IOC(_IOC_WRITE,(type),(nr),sizeof(size))
 #define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))
 
-#define _IOC_DIR(nr)        (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
+/* Used to decode ioctl numbers in drivers despite the leading underscore... */
+#define _IOC_DIR(nr)    \
+ ( (((((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) & (_IOC_WRITE|_IOC_READ)) != 0)?   \
+                            (((nr) >> _IOC_DIRSHIFT) & (_IOC_WRITE|_IOC_READ)):  \
+                            (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) )
 #define _IOC_TYPE(nr)       (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
 #define _IOC_NR(nr)         (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
-#define _IOC_SIZE(nr)       (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
-
-/* ...and for the PCMCIA... */
+#define _IOC_SIZE(nr)       (((nr) >> _IOC_SIZESHIFT) & _IOC_XSIZEMASK)
 
+/* ...and for the PCMCIA and sound. */
 #define IOC_IN          (_IOC_WRITE << _IOC_DIRSHIFT)
 #define IOC_OUT         (_IOC_READ << _IOC_DIRSHIFT)
 #define IOC_INOUT       ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
-#define IOCSIZE_MASK    (_IOC_SIZEMASK << _IOC_SIZESHIFT)
+#define IOCSIZE_MASK    (_IOC_XSIZEMASK << _IOC_SIZESHIFT)
 #define IOCSIZE_SHIFT   (_IOC_SIZESHIFT)
 
 #endif /* !(_SPARC_IOCTL_H) */

include/asm-sparc64/ioctl.h

@@ -2,23 +2,35 @@
 #ifndef _SPARC64_IOCTL_H
 #define _SPARC64_IOCTL_H
 
+/*
+ * Our DIR and SIZE overlap in order to simulteneously provide
+ * a non-zero _IOC_NONE (for binary compatibility) and
+ * 14 bits of size as on i386. Here's the layout:
+ *
+ *   0xE0000000   DIR
+ *   0x80000000     DIR = WRITE
+ *   0x40000000     DIR = READ
+ *   0x20000000     DIR = NONE
+ *   0x3FFF0000   SIZE (overlaps NONE bit)
+ *   0x0000FF00   TYPE
+ *   0x000000FF   NR (CMD)
+ */
+
 #define _IOC_NRBITS      8
 #define _IOC_TYPEBITS    8
-#define _IOC_SIZEBITS    8
-#define _IOC_RESVBITS    5
+#define _IOC_SIZEBITS   13	/* Actually 14, see below. */
 #define _IOC_DIRBITS     3
 
 #define _IOC_NRMASK      ((1 << _IOC_NRBITS)-1)
 #define _IOC_TYPEMASK    ((1 << _IOC_TYPEBITS)-1)
-#define _IOC_RESVMASK    ((1 << _IOC_RESVBITS)-1)
 #define _IOC_SIZEMASK    ((1 << _IOC_SIZEBITS)-1)
+#define _IOC_XSIZEMASK   ((1 << (_IOC_SIZEBITS+1))-1)
 #define _IOC_DIRMASK     ((1 << _IOC_DIRBITS)-1)
 
 #define _IOC_NRSHIFT     0
 #define _IOC_TYPESHIFT   (_IOC_NRSHIFT + _IOC_NRBITS)
 #define _IOC_SIZESHIFT   (_IOC_TYPESHIFT + _IOC_TYPEBITS)
-#define _IOC_RESVSHIFT   (_IOC_SIZESHIFT + _IOC_SIZEBITS)
-#define _IOC_DIRSHIFT    (_IOC_RESVSHIFT + _IOC_RESVBITS)
+#define _IOC_DIRSHIFT    (_IOC_SIZESHIFT + _IOC_SIZEBITS)
 
 #define _IOC_NONE        1U
 #define _IOC_READ        2U
@@ -35,17 +47,20 @@
 #define _IOW(type,nr,size)  _IOC(_IOC_WRITE,(type),(nr),sizeof(size))
 #define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))
 
-#define _IOC_DIR(nr)        (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
+/* Used to decode ioctl numbers in drivers despite the leading underscore... */
+#define _IOC_DIR(nr)    \
+ ( (((((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) & (_IOC_WRITE|_IOC_READ)) != 0)?   \
+                            (((nr) >> _IOC_DIRSHIFT) & (_IOC_WRITE|_IOC_READ)):  \
+                            (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) )
 #define _IOC_TYPE(nr)       (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
 #define _IOC_NR(nr)         (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
-#define _IOC_SIZE(nr)       (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
-
-/* ...and for the PCMCIA... */
+#define _IOC_SIZE(nr)       (((nr) >> _IOC_SIZESHIFT) & _IOC_XSIZEMASK)
 
+/* ...and for the PCMCIA and sound. */
 #define IOC_IN          (_IOC_WRITE << _IOC_DIRSHIFT)
 #define IOC_OUT         (_IOC_READ << _IOC_DIRSHIFT)
 #define IOC_INOUT       ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
-#define IOCSIZE_MASK    (_IOC_SIZEMASK << _IOC_SIZESHIFT)
+#define IOCSIZE_MASK    (_IOC_XSIZEMASK << _IOC_SIZESHIFT)
 #define IOCSIZE_SHIFT   (_IOC_SIZESHIFT)
 
 #endif /* !(_SPARC64_IOCTL_H) */