1#ifndef ETHERBOOT_BITS_BYTESWAP_H
2#define ETHERBOOT_BITS_BYTESWAP_H
3
4FILE_LICENCE ( GPL2_OR_LATER );
5
6static inline __attribute__ ((always_inline, const)) uint16_t
7__bswap_variable_16(uint16_t x)
8{
9	__asm__("xchgb %b0,%h0\n\t"
10		: "=q" (x)
11		: "0" (x));
12	return x;
13}
14
15static inline __attribute__ ((always_inline, const)) uint32_t
16__bswap_variable_32(uint32_t x)
17{
18	__asm__("xchgb %b0,%h0\n\t"
19		"rorl $16,%0\n\t"
20		"xchgb %b0,%h0"
21		: "=q" (x)
22		: "0" (x));
23	return x;
24}
25
26static inline __attribute__ ((always_inline, const)) uint64_t
27__bswap_variable_64(uint64_t x)
28{
29	union {
30		uint64_t qword;
31		uint32_t dword[2];
32	} u;
33
34	u.qword = x;
35	u.dword[0] = __bswap_variable_32(u.dword[0]);
36	u.dword[1] = __bswap_variable_32(u.dword[1]);
37	__asm__("xchgl %0,%1"
38		: "=r" ( u.dword[0] ), "=r" ( u.dword[1] )
39		: "0" ( u.dword[0] ), "1" ( u.dword[1] ) );
40	return u.qword;
41}
42
43#endif /* ETHERBOOT_BITS_BYTESWAP_H */
44