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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /arch/arm64/include/asm/vdso/compat_gettimeofday.h
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/include/asm/vdso/compat_gettimeofday.h')
-rw-r--r--arch/arm64/include/asm/vdso/compat_gettimeofday.h177
1 files changed, 177 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/vdso/compat_gettimeofday.h b/arch/arm64/include/asm/vdso/compat_gettimeofday.h
new file mode 100644
index 000000000..7508b0ac1
--- /dev/null
+++ b/arch/arm64/include/asm/vdso/compat_gettimeofday.h
@@ -0,0 +1,177 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 ARM Limited
+ */
+#ifndef __ASM_VDSO_GETTIMEOFDAY_H
+#define __ASM_VDSO_GETTIMEOFDAY_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/barrier.h>
+#include <asm/unistd.h>
+#include <asm/errno.h>
+
+#include <asm/vdso/compat_barrier.h>
+
+#define VDSO_HAS_CLOCK_GETRES 1
+
+#define BUILD_VDSO32 1
+
+static __always_inline
+int gettimeofday_fallback(struct __kernel_old_timeval *_tv,
+ struct timezone *_tz)
+{
+ register struct timezone *tz asm("r1") = _tz;
+ register struct __kernel_old_timeval *tv asm("r0") = _tv;
+ register long ret asm ("r0");
+ register long nr asm("r7") = __NR_compat_gettimeofday;
+
+ asm volatile(
+ " swi #0\n"
+ : "=r" (ret)
+ : "r" (tv), "r" (tz), "r" (nr)
+ : "memory");
+
+ return ret;
+}
+
+static __always_inline
+long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
+{
+ register struct __kernel_timespec *ts asm("r1") = _ts;
+ register clockid_t clkid asm("r0") = _clkid;
+ register long ret asm ("r0");
+ register long nr asm("r7") = __NR_compat_clock_gettime64;
+
+ asm volatile(
+ " swi #0\n"
+ : "=r" (ret)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "memory");
+
+ return ret;
+}
+
+static __always_inline
+long clock_gettime32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
+{
+ register struct old_timespec32 *ts asm("r1") = _ts;
+ register clockid_t clkid asm("r0") = _clkid;
+ register long ret asm ("r0");
+ register long nr asm("r7") = __NR_compat_clock_gettime;
+
+ asm volatile(
+ " swi #0\n"
+ : "=r" (ret)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "memory");
+
+ return ret;
+}
+
+static __always_inline
+int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
+{
+ register struct __kernel_timespec *ts asm("r1") = _ts;
+ register clockid_t clkid asm("r0") = _clkid;
+ register long ret asm ("r0");
+ register long nr asm("r7") = __NR_compat_clock_getres_time64;
+
+ asm volatile(
+ " swi #0\n"
+ : "=r" (ret)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "memory");
+
+ return ret;
+}
+
+static __always_inline
+int clock_getres32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
+{
+ register struct old_timespec32 *ts asm("r1") = _ts;
+ register clockid_t clkid asm("r0") = _clkid;
+ register long ret asm ("r0");
+ register long nr asm("r7") = __NR_compat_clock_getres;
+
+ asm volatile(
+ " swi #0\n"
+ : "=r" (ret)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "memory");
+
+ return ret;
+}
+
+static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,
+ const struct vdso_data *vd)
+{
+ u64 res;
+
+ /*
+ * Core checks for mode already, so this raced against a concurrent
+ * update. Return something. Core will do another round and then
+ * see the mode change and fallback to the syscall.
+ */
+ if (clock_mode != VDSO_CLOCKMODE_ARCHTIMER)
+ return 0;
+
+ /*
+ * This isb() is required to prevent that the counter value
+ * is speculated.
+ */
+ isb();
+ asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (res));
+ /*
+ * This isb() is required to prevent that the seq lock is
+ * speculated.
+ */
+ isb();
+
+ return res;
+}
+
+static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
+{
+ const struct vdso_data *ret;
+
+ /*
+ * This simply puts &_vdso_data into ret. The reason why we don't use
+ * `ret = _vdso_data` is that the compiler tends to optimise this in a
+ * very suboptimal way: instead of keeping &_vdso_data in a register,
+ * it goes through a relocation almost every time _vdso_data must be
+ * accessed (even in subfunctions). This is both time and space
+ * consuming: each relocation uses a word in the code section, and it
+ * has to be loaded at runtime.
+ *
+ * This trick hides the assignment from the compiler. Since it cannot
+ * track where the pointer comes from, it will only use one relocation
+ * where __arch_get_vdso_data() is called, and then keep the result in
+ * a register.
+ */
+ asm volatile("mov %0, %1" : "=r"(ret) : "r"(_vdso_data));
+
+ return ret;
+}
+
+#ifdef CONFIG_TIME_NS
+static __always_inline const struct vdso_data *__arch_get_timens_vdso_data(void)
+{
+ const struct vdso_data *ret;
+
+ /* See __arch_get_vdso_data(). */
+ asm volatile("mov %0, %1" : "=r"(ret) : "r"(_timens_data));
+
+ return ret;
+}
+#endif
+
+static inline bool vdso_clocksource_ok(const struct vdso_data *vd)
+{
+ return vd->clock_mode == VDSO_CLOCKMODE_ARCHTIMER;
+}
+#define vdso_clocksource_ok vdso_clocksource_ok
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_GETTIMEOFDAY_H */