Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * LoongArch Constant Timer specific interface
4 */
5#ifndef SELFTEST_KVM_ARCH_TIMER_H
6#define SELFTEST_KVM_ARCH_TIMER_H
7
8#include "processor.h"
9
10/* LoongArch timer frequency is constant 100MHZ */
11#define TIMER_FREQ (100UL << 20)
12#define msec_to_cycles(msec) (TIMER_FREQ * (unsigned long)(msec) / 1000)
13#define usec_to_cycles(usec) (TIMER_FREQ * (unsigned long)(usec) / 1000000)
14#define cycles_to_usec(cycles) ((unsigned long)(cycles) * 1000000 / TIMER_FREQ)
15
16static inline unsigned long timer_get_cycles(void)
17{
18 unsigned long val = 0;
19
20 __asm__ __volatile__(
21 "rdtime.d %0, $zero\n\t"
22 : "=r"(val)
23 :
24 );
25
26 return val;
27}
28
29static inline unsigned long timer_get_cfg(void)
30{
31 return csr_read(LOONGARCH_CSR_TCFG);
32}
33
34static inline unsigned long timer_get_val(void)
35{
36 return csr_read(LOONGARCH_CSR_TVAL);
37}
38
39static inline void disable_timer(void)
40{
41 csr_write(0, LOONGARCH_CSR_TCFG);
42}
43
44static inline void timer_irq_enable(void)
45{
46 unsigned long val;
47
48 val = csr_read(LOONGARCH_CSR_ECFG);
49 val |= ECFGF_TIMER;
50 csr_write(val, LOONGARCH_CSR_ECFG);
51}
52
53static inline void timer_irq_disable(void)
54{
55 unsigned long val;
56
57 val = csr_read(LOONGARCH_CSR_ECFG);
58 val &= ~ECFGF_TIMER;
59 csr_write(val, LOONGARCH_CSR_ECFG);
60}
61
62static inline void timer_set_next_cmp_ms(unsigned int msec, bool period)
63{
64 unsigned long val;
65
66 val = msec_to_cycles(msec) & CSR_TCFG_VAL;
67 val |= CSR_TCFG_EN;
68 if (period)
69 val |= CSR_TCFG_PERIOD;
70 csr_write(val, LOONGARCH_CSR_TCFG);
71}
72
73static inline void __delay(u64 cycles)
74{
75 u64 start = timer_get_cycles();
76
77 while ((timer_get_cycles() - start) < cycles)
78 cpu_relax();
79}
80
81static inline void udelay(unsigned long usec)
82{
83 __delay(usec_to_cycles(usec));
84}
85#endif /* SELFTEST_KVM_ARCH_TIMER_H */