| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <arch/lib_helpers.h> |
| #include <commonlib/bsd/gcd.h> |
| #include <timer.h> |
| |
| void timer_monotonic_get(struct mono_time *mt) |
| { |
| uint64_t tvalue = raw_read_cntpct_el0(); |
| static uint32_t tfreq, mult; |
| uint32_t div; |
| |
| /* |
| * The value from raw_read_cntfrq_el0() could be large enough to |
| * cause overflow when multiplied by USECS_PER_SEC. To prevent this, |
| * both USECS_PER_SEC. and tfreq can be reduced by dividing them by |
| * their GCD. |
| */ |
| if (tfreq == 0) { |
| tfreq = raw_read_cntfrq_el0(); |
| mult = USECS_PER_SEC; |
| div = gcd32(tfreq, mult); |
| tfreq /= div; |
| mult /= div; |
| } |
| |
| long usecs = (tvalue * mult) / tfreq; |
| mono_time_set_usecs(mt, usecs); |
| } |