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| author | Dave Airlie <airlied@redhat.com> | 2026-09-26 07:57:59 +1000 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2026-09-26 07:58:24 +1000 |
| commit | a9ed3aa9b87ee41e8ab3ff471b1331c154767e45 (patch) | |
| tree | cc62d74e0eb4905246978674461e78e2f9df2afd /arch/arm64/lib/delay.c | |
| download | linux-stable-a9ed3aa9b87ee41e8ab3ff471b1331c154767e45.tar.gz linux-stable-a9ed3aa9b87ee41e8ab3ff471b1331c154767e45.zip | |
Merge tag 'drm-misc-fixes-2026-09-24' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixesgrafted
A number of fixes:
- bridge:
- samsung-dsim: fix GPIO lifetime
- client: Null pointer dereference fix
- imagination: error handling fix, page handling fix
- nouveau: fix reference leaks, double-frees, out-of-bounds accesses,
use-after-frees, don't reject config without SCDC, a number of
workarounds
- virtio: fix memory leak, reference leaks, null pointer dereference,
add pixel blend mode, cache coherency fix
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maxime Ripard <self@mripard.dev>
Link: https://patch.msgid.link/arU22zzqUGDEco1y@houat
Diffstat (limited to 'arch/arm64/lib/delay.c')
| -rw-r--r-- | arch/arm64/lib/delay.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/arm64/lib/delay.c b/arch/arm64/lib/delay.c new file mode 100644 index 000000000..e278e060e --- /dev/null +++ b/arch/arm64/lib/delay.c @@ -0,0 +1,84 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Delay loops based on the OpenRISC implementation. + * + * Copyright (C) 2012 ARM Limited + * + * Author: Will Deacon <will.deacon@arm.com> + */ + +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/timex.h> + +#include <clocksource/arm_arch_timer.h> + +#define USECS_TO_CYCLES(time_usecs) \ + xloops_to_cycles((time_usecs) * 0x10C7UL) + +static inline unsigned long xloops_to_cycles(unsigned long xloops) +{ + return (xloops * loops_per_jiffy * HZ) >> 32; +} + +/* + * Force the use of CNTVCT_EL0 in order to have the same base as WFxT. + * This avoids some annoying issues when CNTVOFF_EL2 is not reset 0 on a + * KVM host running at EL1 until we do a vcpu_put() on the vcpu. When + * running at EL2, the effective offset is always 0. + * + * Note that userspace cannot change the offset behind our back either, + * as the vcpu mutex is held as long as KVM_RUN is in progress. + */ +static cycles_t notrace __delay_cycles(void) +{ + guard(preempt_notrace)(); + return __arch_counter_get_cntvct_stable(); +} + +void __delay(unsigned long cycles) +{ + cycles_t start = __delay_cycles(); + + if (alternative_has_cap_unlikely(ARM64_HAS_WFXT)) { + u64 end = start + cycles; + + /* + * Start with WFIT. If an interrupt makes us resume + * early, use a WFET loop to complete the delay. + */ + wfit(end); + while ((__delay_cycles() - start) < cycles) + wfet(end); + } else if (arch_timer_evtstrm_available()) { + const cycles_t timer_evt_period = + USECS_TO_CYCLES(ARCH_TIMER_EVT_STREAM_PERIOD_US); + + while ((__delay_cycles() - start + timer_evt_period) < cycles) + wfe(); + } + + while ((__delay_cycles() - start) < cycles) + cpu_relax(); +} +EXPORT_SYMBOL(__delay); + +inline void __const_udelay(unsigned long xloops) +{ + __delay(xloops_to_cycles(xloops)); +} +EXPORT_SYMBOL(__const_udelay); + +void __udelay(unsigned long usecs) +{ + __const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */ +} +EXPORT_SYMBOL(__udelay); + +void __ndelay(unsigned long nsecs) +{ + __const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */ +} +EXPORT_SYMBOL(__ndelay); |
