Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "The timer and timekeeping departement delivers:

  Core:

   - The consolidation of the VDSO code into a generic library including
     the conversion of x86 and ARM64. Conversion of ARM and MIPS are en
     route through the relevant maintainer trees and should end up in
     5.4.

     This gets rid of the unnecessary different copies of the same code
     and brings all architectures on the same level of VDSO
     functionality.

   - Make the NTP user space interface more robust by restricting the
     TAI offset to prevent undefined behaviour. Includes a selftest.

   - Validate user input in the compat settimeofday() syscall to catch
     invalid values which would be turned into valid values by a
     multiplication overflow

   - Consolidate the time accessors

   - Small fixes, improvements and cleanups all over the place

  Drivers:

   - Support for the NXP system counter, TI davinci timer

   - Move the Microsoft HyperV clocksource/events code into the
     drivers/clocksource directory so it can be shared between x86 and
     ARM64.

   - Overhaul of the Tegra driver

   - Delay timer support for IXP4xx

   - Small fixes, improvements and cleanups as usual"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  time: Validate user input in compat_settimeofday()
  timer: Document TIMER_PINNED
  clocksource/drivers: Continue making Hyper-V clocksource ISA agnostic
  clocksource/drivers: Make Hyper-V clocksource ISA agnostic
  MAINTAINERS: Fix Andy's surname and the directory entries of VDSO
  hrtimer: Use a bullet for the returns bullet list
  arm64: vdso: Fix compilation with clang older than 8
  arm64: compat: Fix __arch_get_hw_counter() implementation
  arm64: Fix __arch_get_hw_counter() implementation
  lib/vdso: Make delta calculation work correctly
  MAINTAINERS: Add entry for the generic VDSO library
  arm64: compat: No need for pre-ARMv7 barriers on an ARMv8 system
  arm64: vdso: Remove unnecessary asm-offsets.c definitions
  vdso: Remove superfluous #ifdef __KERNEL__ in vdso/datapage.h
  clocksource/drivers/davinci: Add support for clocksource
  clocksource/drivers/davinci: Add support for clockevents
  clocksource/drivers/tegra: Set up maximum-ticks limit properly
  clocksource/drivers/tegra: Cycles can't be 0
  clocksource/drivers/tegra: Restore base address before cleanup
  clocksource/drivers/tegra: Add verbose definition for 1MHz constant
  ...

2 files changed, 151 insertions, 0 deletions

diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h
new file mode 100644
index 000000000000..a821deb8ecb2
--- /dev/null
+++ b/include/clocksource/hyperv_timer.h
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Definitions for the clocksource provided by the Hyper-V
+ * hypervisor to guest VMs, as described in the Hyper-V Top
+ * Level Functional Spec (TLFS).
+ *
+ * Copyright (C) 2019, Microsoft, Inc.
+ *
+ * Author:  Michael Kelley <mikelley@microsoft.com>
+ */
+
+#ifndef __CLKSOURCE_HYPERV_TIMER_H
+#define __CLKSOURCE_HYPERV_TIMER_H
+
+#include <linux/clocksource.h>
+#include <linux/math64.h>
+#include <asm/mshyperv.h>
+
+#define HV_MAX_MAX_DELTA_TICKS 0xffffffff
+#define HV_MIN_DELTA_TICKS 1
+
+/* Routines called by the VMbus driver */
+extern int hv_stimer_alloc(int sint);
+extern void hv_stimer_free(void);
+extern void hv_stimer_init(unsigned int cpu);
+extern void hv_stimer_cleanup(unsigned int cpu);
+extern void hv_stimer_global_cleanup(void);
+extern void hv_stimer0_isr(void);
+
+#if IS_ENABLED(CONFIG_HYPERV)
+extern struct clocksource *hyperv_cs;
+extern void hv_init_clocksource(void);
+#endif /* CONFIG_HYPERV */
+
+#ifdef CONFIG_HYPERV_TSCPAGE
+extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
+
+static inline notrace u64
+hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg, u64 *cur_tsc)
+{
+	u64 scale, offset;
+	u32 sequence;
+
+	/*
+	 * The protocol for reading Hyper-V TSC page is specified in Hypervisor
+	 * Top-Level Functional Specification ver. 3.0 and above. To get the
+	 * reference time we must do the following:
+	 * - READ ReferenceTscSequence
+	 *   A special '0' value indicates the time source is unreliable and we
+	 *   need to use something else. The currently published specification
+	 *   versions (up to 4.0b) contain a mistake and wrongly claim '-1'
+	 *   instead of '0' as the special value, see commit c35b82ef0294.
+	 * - ReferenceTime =
+	 *        ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset
+	 * - READ ReferenceTscSequence again. In case its value has changed
+	 *   since our first reading we need to discard ReferenceTime and repeat
+	 *   the whole sequence as the hypervisor was updating the page in
+	 *   between.
+	 */
+	do {
+		sequence = READ_ONCE(tsc_pg->tsc_sequence);
+		if (!sequence)
+			return U64_MAX;
+		/*
+		 * Make sure we read sequence before we read other values from
+		 * TSC page.
+		 */
+		smp_rmb();
+
+		scale = READ_ONCE(tsc_pg->tsc_scale);
+		offset = READ_ONCE(tsc_pg->tsc_offset);
+		*cur_tsc = hv_get_raw_timer();
+
+		/*
+		 * Make sure we read sequence after we read all other values
+		 * from TSC page.
+		 */
+		smp_rmb();
+
+	} while (READ_ONCE(tsc_pg->tsc_sequence) != sequence);
+
+	return mul_u64_u64_shr(*cur_tsc, scale, 64) + offset;
+}
+
+static inline notrace u64
+hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
+{
+	u64 cur_tsc;
+
+	return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc);
+}
+
+#else /* CONFIG_HYPERV_TSC_PAGE */
+static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
+{
+	return NULL;
+}
+
+static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
+				       u64 *cur_tsc)
+{
+	return U64_MAX;
+}
+#endif /* CONFIG_HYPERV_TSCPAGE */
+
+#endif
diff --git a/include/clocksource/timer-davinci.h b/include/clocksource/timer-davinci.h
new file mode 100644
index 000000000000..1dcc1333fbc8
--- /dev/null
+++ b/include/clocksource/timer-davinci.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * TI DaVinci clocksource driver
+ *
+ * Copyright (C) 2019 Texas Instruments
+ * Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
+ */
+
+#ifndef __TIMER_DAVINCI_H__
+#define __TIMER_DAVINCI_H__
+
+#include <linux/clk.h>
+#include <linux/ioport.h>
+
+enum {
+	DAVINCI_TIMER_CLOCKEVENT_IRQ,
+	DAVINCI_TIMER_CLOCKSOURCE_IRQ,
+	DAVINCI_TIMER_NUM_IRQS,
+};
+
+/**
+ * struct davinci_timer_cfg - davinci clocksource driver configuration struct
+ * @reg:        register range resource
+ * @irq:        clockevent and clocksource interrupt resources
+ * @cmp_off:    if set - it specifies the compare register used for clockevent
+ *
+ * Note: if the compare register is specified, the driver will use the bottom
+ * clock half for both clocksource and clockevent and the compare register
+ * to generate event irqs. The user must supply the correct compare register
+ * interrupt number.
+ *
+ * This is only used by da830 the DSP of which uses the top half. The timer
+ * driver still configures the top half to run in free-run mode.
+ */
+struct davinci_timer_cfg {
+	struct resource reg;
+	struct resource irq[DAVINCI_TIMER_NUM_IRQS];
+	unsigned int cmp_off;
+};
+
+int __init davinci_timer_register(struct clk *clk,
+				  const struct davinci_timer_cfg *data);
+
+#endif /* __TIMER_DAVINCI_H__ */