xref: /openbmc/linux/arch/powerpc/include/asm/timex.h (revision d0e22329)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_POWERPC_TIMEX_H
3 #define _ASM_POWERPC_TIMEX_H
4 
5 #ifdef __KERNEL__
6 
7 /*
8  * PowerPC architecture timex specifications
9  */
10 
11 #include <asm/cputable.h>
12 #include <asm/reg.h>
13 
14 #define CLOCK_TICK_RATE	1024000 /* Underlying HZ */
15 
16 typedef unsigned long cycles_t;
17 
18 static inline cycles_t get_cycles(void)
19 {
20 #ifdef __powerpc64__
21 	return mftb();
22 #else
23 	cycles_t ret;
24 
25 	/*
26 	 * For the "cycle" counter we use the timebase lower half.
27 	 * Currently only used on SMP.
28 	 */
29 
30 	ret = 0;
31 
32 	__asm__ __volatile__(
33 #ifdef CONFIG_PPC_8xx
34 		"97:	mftb %0\n"
35 #else
36 		"97:	mfspr %0, %2\n"
37 #endif
38 		"99:\n"
39 		".section __ftr_fixup,\"a\"\n"
40 		".align 2\n"
41 		"98:\n"
42 		"	.long %1\n"
43 		"	.long 0\n"
44 		"	.long 97b-98b\n"
45 		"	.long 99b-98b\n"
46 		"	.long 0\n"
47 		"	.long 0\n"
48 		".previous"
49 		: "=r" (ret) : "i" (CPU_FTR_601), "i" (SPRN_TBRL));
50 	return ret;
51 #endif
52 }
53 
54 #endif	/* __KERNEL__ */
55 #endif	/* _ASM_POWERPC_TIMEX_H */
56