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-rw-r--r--arch/arm64/include/asm/arch_timer.h235
1 files changed, 235 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h
new file mode 100644
index 000000000..af1fafbe7
--- /dev/null
+++ b/arch/arm64/include/asm/arch_timer.h
@@ -0,0 +1,235 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * arch/arm64/include/asm/arch_timer.h
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+#ifndef __ASM_ARCH_TIMER_H
+#define __ASM_ARCH_TIMER_H
+
+#include <asm/barrier.h>
+#include <asm/hwcap.h>
+#include <asm/sysreg.h>
+
+#include <linux/bug.h>
+#include <linux/init.h>
+#include <linux/jump_label.h>
+#include <linux/smp.h>
+#include <linux/types.h>
+
+#include <clocksource/arm_arch_timer.h>
+
+#if IS_ENABLED(CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND)
+#define has_erratum_handler(h) \
+ ({ \
+ const struct arch_timer_erratum_workaround *__wa; \
+ __wa = __this_cpu_read(timer_unstable_counter_workaround); \
+ (__wa && __wa->h); \
+ })
+
+#define erratum_handler(h) \
+ ({ \
+ const struct arch_timer_erratum_workaround *__wa; \
+ __wa = __this_cpu_read(timer_unstable_counter_workaround); \
+ (__wa && __wa->h) ? ({ isb(); __wa->h;}) : arch_timer_##h; \
+ })
+
+#else
+#define has_erratum_handler(h) false
+#define erratum_handler(h) (arch_timer_##h)
+#endif
+
+enum arch_timer_erratum_match_type {
+ ate_match_dt,
+ ate_match_local_cap_id,
+ ate_match_acpi_oem_info,
+};
+
+struct clock_event_device;
+
+struct arch_timer_erratum_workaround {
+ enum arch_timer_erratum_match_type match_type;
+ const void *id;
+ const char *desc;
+ u64 (*read_cntpct_el0)(void);
+ u64 (*read_cntvct_el0)(void);
+ int (*set_next_event_phys)(unsigned long, struct clock_event_device *);
+ int (*set_next_event_virt)(unsigned long, struct clock_event_device *);
+ bool disable_compat_vdso;
+};
+
+DECLARE_PER_CPU(const struct arch_timer_erratum_workaround *,
+ timer_unstable_counter_workaround);
+
+static inline notrace u64 arch_timer_read_cntpct_el0(void)
+{
+ u64 cnt;
+
+ asm volatile(ALTERNATIVE("isb\n mrs %0, cntpct_el0",
+ "nop\n" __mrs_s("%0", SYS_CNTPCTSS_EL0),
+ ARM64_HAS_ECV)
+ : "=r" (cnt));
+
+ return cnt;
+}
+
+static inline notrace u64 arch_timer_read_cntvct_el0(void)
+{
+ u64 cnt;
+
+ asm volatile(ALTERNATIVE("isb\n mrs %0, cntvct_el0",
+ "nop\n" __mrs_s("%0", SYS_CNTVCTSS_EL0),
+ ARM64_HAS_ECV)
+ : "=r" (cnt));
+
+ return cnt;
+}
+
+#define arch_timer_reg_read_stable(reg) \
+ ({ \
+ u64 _val; \
+ \
+ preempt_disable_notrace(); \
+ _val = erratum_handler(read_ ## reg)(); \
+ preempt_enable_notrace(); \
+ \
+ _val; \
+ })
+
+/*
+ * These register accessors are marked inline so the compiler can
+ * nicely work out which register we want, and chuck away the rest of
+ * the code.
+ */
+static __always_inline
+void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u64 val)
+{
+ if (access == ARCH_TIMER_PHYS_ACCESS) {
+ switch (reg) {
+ case ARCH_TIMER_REG_CTRL:
+ write_sysreg(val, cntp_ctl_el0);
+ isb();
+ break;
+ case ARCH_TIMER_REG_CVAL:
+ write_sysreg(val, cntp_cval_el0);
+ break;
+ default:
+ BUILD_BUG();
+ }
+ } else if (access == ARCH_TIMER_VIRT_ACCESS) {
+ switch (reg) {
+ case ARCH_TIMER_REG_CTRL:
+ write_sysreg(val, cntv_ctl_el0);
+ isb();
+ break;
+ case ARCH_TIMER_REG_CVAL:
+ write_sysreg(val, cntv_cval_el0);
+ break;
+ default:
+ BUILD_BUG();
+ }
+ } else {
+ BUILD_BUG();
+ }
+}
+
+static __always_inline
+u64 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg)
+{
+ if (access == ARCH_TIMER_PHYS_ACCESS) {
+ switch (reg) {
+ case ARCH_TIMER_REG_CTRL:
+ return read_sysreg(cntp_ctl_el0);
+ default:
+ BUILD_BUG();
+ }
+ } else if (access == ARCH_TIMER_VIRT_ACCESS) {
+ switch (reg) {
+ case ARCH_TIMER_REG_CTRL:
+ return read_sysreg(cntv_ctl_el0);
+ default:
+ BUILD_BUG();
+ }
+ }
+
+ BUILD_BUG();
+ unreachable();
+}
+
+static inline u32 arch_timer_get_cntfrq(void)
+{
+ return read_sysreg(cntfrq_el0);
+}
+
+static inline u32 arch_timer_get_cntkctl(void)
+{
+ return read_sysreg(cntkctl_el1);
+}
+
+static inline void arch_timer_set_cntkctl(u32 cntkctl)
+{
+ write_sysreg(cntkctl, cntkctl_el1);
+ isb();
+}
+
+static __always_inline u64 __arch_counter_get_cntpct_stable(void)
+{
+ u64 cnt;
+
+ cnt = arch_timer_reg_read_stable(cntpct_el0);
+ arch_counter_enforce_ordering(cnt);
+ return cnt;
+}
+
+static __always_inline u64 __arch_counter_get_cntpct(void)
+{
+ u64 cnt;
+
+ asm volatile(ALTERNATIVE("isb\n mrs %0, cntpct_el0",
+ "nop\n" __mrs_s("%0", SYS_CNTPCTSS_EL0),
+ ARM64_HAS_ECV)
+ : "=r" (cnt));
+ arch_counter_enforce_ordering(cnt);
+ return cnt;
+}
+
+static __always_inline u64 __arch_counter_get_cntvct_stable(void)
+{
+ u64 cnt;
+
+ cnt = arch_timer_reg_read_stable(cntvct_el0);
+ arch_counter_enforce_ordering(cnt);
+ return cnt;
+}
+
+static __always_inline u64 __arch_counter_get_cntvct(void)
+{
+ u64 cnt;
+
+ asm volatile(ALTERNATIVE("isb\n mrs %0, cntvct_el0",
+ "nop\n" __mrs_s("%0", SYS_CNTVCTSS_EL0),
+ ARM64_HAS_ECV)
+ : "=r" (cnt));
+ arch_counter_enforce_ordering(cnt);
+ return cnt;
+}
+
+static inline int arch_timer_arch_init(void)
+{
+ return 0;
+}
+
+static inline void arch_timer_set_evtstrm_feature(void)
+{
+ cpu_set_named_feature(EVTSTRM);
+#ifdef CONFIG_COMPAT
+ compat_elf_hwcap |= COMPAT_HWCAP_EVTSTRM;
+#endif
+}
+
+static inline bool arch_timer_have_evtstrm_feature(void)
+{
+ return cpu_have_named_feature(EVTSTRM);
+}
+#endif