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| author | Tom Rini <trini@konsulko.com> | 2024-07-01 13:17:56 -0600 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2024-07-01 15:00:56 -0600 |
| commit | 65fbdab27224ee3943a89496b21862db83c34da2 (patch) | |
| tree | 775a0a54066c2e9a6bbba201676e3d896b5cb0e2 /arch/arm/cpu/armv8/generic_timer.c | |
| parent | 3f772959501c99fbe5aa0b22a36efe3478d1ae1c (diff) | |
| parent | b4cbd1a257d4027038b4f997d73bdb0a066db045 (diff) | |
Merge branch 'next'
Diffstat (limited to 'arch/arm/cpu/armv8/generic_timer.c')
| -rw-r--r-- | arch/arm/cpu/armv8/generic_timer.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/arch/arm/cpu/armv8/generic_timer.c b/arch/arm/cpu/armv8/generic_timer.c index 8f83372cbca..1de7ec596fc 100644 --- a/arch/arm/cpu/armv8/generic_timer.c +++ b/arch/arm/cpu/armv8/generic_timer.c @@ -4,7 +4,6 @@ * David Feng <fenghua@phytium.com.cn> */ -#include <common.h> #include <bootstage.h> #include <command.h> #include <time.h> @@ -115,3 +114,30 @@ ulong timer_get_boot_us(void) return val / get_tbclk(); } + +#if CONFIG_IS_ENABLED(ARMV8_UDELAY_EVENT_STREAM) +void __udelay(unsigned long usec) +{ + u64 target = get_ticks() + usec_to_tick(usec); + + /* At EL2 or above, use the event stream to avoid polling CNTPCT_EL0 so often */ + if (current_el() >= 2) { + u32 cnthctl_val; + const u8 event_period = 0x7; + + asm volatile("mrs %0, cnthctl_el2" : "=r" (cnthctl_val)); + asm volatile("msr cnthctl_el2, %0" : : "r" + (cnthctl_val | CNTHCTL_EL2_EVNT_EN | CNTHCTL_EL2_EVNT_I(event_period))); + + while (get_ticks() + (1ULL << event_period) <= target) + wfe(); + + /* Reset the event stream */ + asm volatile("msr cnthctl_el2, %0" : : "r" (cnthctl_val)); + } + + /* Fall back to polling CNTPCT_EL0 */ + while (get_ticks() <= target) + ; +} +#endif |