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authorSang-Heon Jeon <ekffu200098@gmail.com>2026-08-24 01:18:14 +0900
committerJulia Lawall <Julia.Lawall@inria.fr>2026-08-23 22:12:11 +0200
commit2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c (patch)
treedcc4da1d99f17541c5590ac63c77da4bf372a4ab /arch/arm64/lib/delay.c
downloadlinux-stable-2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c.tar.gz
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coccinelle: alloc_cast: drop removed allocatorsgrafted
- pci_alloc_consistent() and pci_zalloc_consistent() were removed by commit 7968778914e5 ("PCI: Remove the deprecated "pci-dma-compat.h" API") - kmem_alloc() was removed by commit f078d4ea8276 ("xfs: convert kmem_alloc() to kmalloc()") - kmem_zalloc() was removed by commit 10634530f7ba ("xfs: convert kmem_zalloc() to kzalloc()") - kmem_zone_alloc() and kmem_zone_zalloc() were removed by commit bae633a4a283 ("xfs: remove xfs_zone_{alloc,zalloc} helpers") So drop them from the rules. No functional change. Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com> Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Diffstat (limited to 'arch/arm64/lib/delay.c')
-rw-r--r--arch/arm64/lib/delay.c84
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);