1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2003, 2004 Ralf Baechle
7  */
8 #ifndef __ASM_MACH_GENERIC_MANGLE_PORT_H
9 #define __ASM_MACH_GENERIC_MANGLE_PORT_H
10 
11 #include <asm/byteorder.h>
12 
13 #ifdef __BIG_ENDIAN
14 
15 # define __swizzle_addr_b(port)	(port)
16 # define __swizzle_addr_w(port)	(port)
17 # define __swizzle_addr_l(port)	(port)
18 # define __swizzle_addr_q(port)	(port)
19 
20 #else /* __LITTLE_ENDIAN */
21 
22 static inline bool __should_swizzle_addr(unsigned long p)
23 {
24 	/* boot bus? */
25 	return ((p >> 40) & 0xff) == 0;
26 }
27 
28 # define __swizzle_addr_b(port)	\
29 	(__should_swizzle_addr(port) ? (port) ^ 7 : (port))
30 # define __swizzle_addr_w(port)	\
31 	(__should_swizzle_addr(port) ? (port) ^ 6 : (port))
32 # define __swizzle_addr_l(port)	\
33 	(__should_swizzle_addr(port) ? (port) ^ 4 : (port))
34 # define __swizzle_addr_q(port)	(port)
35 
36 #endif /* __BIG_ENDIAN */
37 
38 /*
39  * Sane hardware offers swapping of PCI/ISA I/O space accesses in hardware;
40  * less sane hardware forces software to fiddle with this...
41  *
42  * Regardless, if the host bus endianness mismatches that of PCI/ISA, then
43  * you can't have the numerical value of data and byte addresses within
44  * multibyte quantities both preserved at the same time.  Hence two
45  * variations of functions: non-prefixed ones that preserve the value
46  * and prefixed ones that preserve byte addresses.  The latters are
47  * typically used for moving raw data between a peripheral and memory (cf.
48  * string I/O functions), hence the "__mem_" prefix.
49  */
50 #if defined(CONFIG_SWAP_IO_SPACE)
51 
52 # define ioswabb(a, x)		(x)
53 # define __mem_ioswabb(a, x)	(x)
54 # define ioswabw(a, x)		le16_to_cpu(x)
55 # define __mem_ioswabw(a, x)	(x)
56 # define ioswabl(a, x)		le32_to_cpu(x)
57 # define __mem_ioswabl(a, x)	(x)
58 # define ioswabq(a, x)		le64_to_cpu(x)
59 # define __mem_ioswabq(a, x)	(x)
60 
61 #else
62 
63 # define ioswabb(a, x)		(x)
64 # define __mem_ioswabb(a, x)	(x)
65 # define ioswabw(a, x)		(x)
66 # define __mem_ioswabw(a, x)	cpu_to_le16(x)
67 # define ioswabl(a, x)		(x)
68 # define __mem_ioswabl(a, x)	cpu_to_le32(x)
69 # define ioswabq(a, x)		(x)
70 # define __mem_ioswabq(a, x)	cpu_to_le32(x)
71 
72 #endif
73 
74 #endif /* __ASM_MACH_GENERIC_MANGLE_PORT_H */
75