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

Pull timer and clockevent updates from Thomas Gleixner:
 "The time(r) core and clockevent updates are mostly boring this time:

   - A new driver for the Tegra210 timer

   - Small fixes and improvements alll over the place

   - Documentation updates and cleanups"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
  soc/tegra: default select TEGRA_TIMER for Tegra210
  clocksource/drivers/tegra: Add Tegra210 timer support
  dt-bindings: timer: add Tegra210 timer
  clocksource/drivers/timer-cs5535: Rename the file for consistency
  clocksource/drivers/timer-pxa: Rename the file for consistency
  clocksource/drivers/tango-xtal: Rename the file for consistency
  dt-bindings: timer: gpt: update binding doc
  clocksource/drivers/exynos_mct: Remove unused header includes
  dt-bindings: timer: mediatek: update bindings for MT7629 SoC
  clocksource/drivers/exynos_mct: Fix error path in timer resources initialization
  clocksource/drivers/exynos_mct: Remove dead code
  clocksource/drivers/riscv: Add required checks during clock source init
  dt-bindings: timer: renesas: tmu: Document r8a774c0 bindings
  dt-bindings: timer: renesas, cmt: Document r8a774c0 CMT support
  clocksource/drivers/exynos_mct: Clear timer interrupt when shutdown
  clocksource/drivers/exynos_mct: Move one-shot check from tick clear to ISR
  clocksource/drivers/arch_timer: Workaround for Allwinner A64 timer instability
  clocksource/drivers/sun5i: Fail gracefully when clock rate is unavailable
  timers: Mark expected switch fall-throughs
  timekeeping/debug: No need to check return value of debugfs_create functions
  ...

Documentation/arm64/silicon-errata.txt

@@ -44,6 +44,8 @@ stable kernels.
 
 | Implementor    | Component       | Erratum ID      | Kconfig                     |
 +----------------+-----------------+-----------------+-----------------------------+
+| Allwinner      | A64/R18         | UNKNOWN1        | SUN50I_ERRATUM_UNKNOWN1     |
+|                |                 |                 |                             |
 | ARM            | Cortex-A53      | #826319         | ARM64_ERRATUM_826319        |
 | ARM            | Cortex-A53      | #827319         | ARM64_ERRATUM_827319        |
 | ARM            | Cortex-A53      | #824069         | ARM64_ERRATUM_824069        |

Documentation/devicetree/bindings/timer/fsl,imxgpt.txt

@@ -2,17 +2,44 @@ Freescale i.MX General Purpose Timer (GPT)
 
 Required properties:
 
-- compatible : should be "fsl,<soc>-gpt"
-- reg : Specifies base physical address and size of the registers.
-- interrupts : A list of 4 interrupts; one per timer channel.
-- clocks : The clocks provided by the SoC to drive the timer.
+- compatible : should be one of following:
+  for i.MX1:
+  - "fsl,imx1-gpt";
+  for i.MX21:
+  - "fsl,imx21-gpt";
+  for i.MX27:
+  - "fsl,imx27-gpt", "fsl,imx21-gpt";
+  for i.MX31:
+  - "fsl,imx31-gpt";
+  for i.MX25:
+  - "fsl,imx25-gpt", "fsl,imx31-gpt";
+  for i.MX50:
+  - "fsl,imx50-gpt", "fsl,imx31-gpt";
+  for i.MX51:
+  - "fsl,imx51-gpt", "fsl,imx31-gpt";
+  for i.MX53:
+  - "fsl,imx53-gpt", "fsl,imx31-gpt";
+  for i.MX6Q:
+  - "fsl,imx6q-gpt", "fsl,imx31-gpt";
+  for i.MX6DL:
+  - "fsl,imx6dl-gpt";
+  for i.MX6SL:
+  - "fsl,imx6sl-gpt", "fsl,imx6dl-gpt";
+  for i.MX6SX:
+  - "fsl,imx6sx-gpt", "fsl,imx6dl-gpt";
+- reg : specifies base physical address and size of the registers.
+- interrupts : should be the gpt interrupt.
+- clocks : the clocks provided by the SoC to drive the timer, must contain
+           an entry for each entry in clock-names.
+- clock-names : must include "ipg" entry first, then "per" entry.
 
 Example:
 
 gpt1: timer@10003000 {
-	compatible = "fsl,imx27-gpt", "fsl,imx1-gpt";
+	compatible = "fsl,imx27-gpt", "fsl,imx21-gpt";
 	reg = <0x10003000 0x1000>;
 	interrupts = <26>;
-	clocks = <&clks 46>, <&clks 61>;
+	clocks = <&clks IMX27_CLK_GPT1_IPG_GATE>,
+		 <&clks IMX27_CLK_PER1_GATE>;
 	clock-names = "ipg", "per";
 };

Documentation/devicetree/bindings/timer/mediatek,mtk-timer.txt

-Mediatek Timers
+MediaTek Timers
 ---------------
 
-Mediatek SoCs have two different timers on different platforms,
+MediaTek SoCs have two different timers on different platforms,
 - GPT (General Purpose Timer)
 - SYST (System Timer)
 
@@ -9,6 +9,7 @@ The proper timer will be selected automatically by driver.
 
 Required properties:
 - compatible should contain:
+	For those SoCs that use GPT
 	* "mediatek,mt2701-timer" for MT2701 compatible timers (GPT)
 	* "mediatek,mt6580-timer" for MT6580 compatible timers (GPT)
 	* "mediatek,mt6589-timer" for MT6589 compatible timers (GPT)
@@ -17,7 +18,11 @@ Required properties:
 	* "mediatek,mt8135-timer" for MT8135 compatible timers (GPT)
 	* "mediatek,mt8173-timer" for MT8173 compatible timers (GPT)
 	* "mediatek,mt6577-timer" for MT6577 and all above compatible timers (GPT)
-	* "mediatek,mt6765-timer" for MT6765 compatible timers (SYST)
+
+	For those SoCs that use SYST
+	* "mediatek,mt7629-timer" for MT7629 compatible timers (SYST)
+	* "mediatek,mt6765-timer" for MT6765 and all above compatible timers (SYST)
+
 - reg: Should contain location and length for timer register.
 - clocks: Should contain system clock.
 

Documentation/devicetree/bindings/timer/nvidia,tegra210-timer.txt

+NVIDIA Tegra210 timer
+
+The Tegra210 timer provides fourteen 29-bit timer counters and one 32-bit
+timestamp counter. The TMRs run at either a fixed 1 MHz clock rate derived
+from the oscillator clock (TMR0-TMR9) or directly at the oscillator clock
+(TMR10-TMR13). Each TMR can be programmed to generate one-shot, periodic,
+or watchdog interrupts.
+
+Required properties:
+- compatible : "nvidia,tegra210-timer".
+- reg : Specifies base physical address and size of the registers.
+- interrupts : A list of 14 interrupts; one per each timer channels 0 through
+  13.
+- clocks : Must contain one entry, for the module clock.
+  See ../clocks/clock-bindings.txt for details.
+
+timer@60005000 {
+	compatible = "nvidia,tegra210-timer";
+	reg = <0x0 0x60005000 0x0 0x400>;
+	interrupts = <GIC_SPI 156 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 0 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 1 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 41 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 42 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 121 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 152 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 155 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 177 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 178 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 179 IRQ_TYPE_LEVEL_HIGH>;
+	clocks = <&tegra_car TEGRA210_CLK_TIMER>;
+	clock-names = "timer";
+};

Documentation/devicetree/bindings/timer/renesas,cmt.txt

@@ -32,6 +32,8 @@ Required Properties:
     - "renesas,r8a77470-cmt1" for the 48-bit CMT1 device included in r8a77470.
     - "renesas,r8a774a1-cmt0" for the 32-bit CMT0 device included in r8a774a1.
     - "renesas,r8a774a1-cmt1" for the 48-bit CMT1 device included in r8a774a1.
+    - "renesas,r8a774c0-cmt0" for the 32-bit CMT0 device included in r8a774c0.
+    - "renesas,r8a774c0-cmt1" for the 48-bit CMT1 device included in r8a774c0.
     - "renesas,r8a7790-cmt0" for the 32-bit CMT0 device included in r8a7790.
     - "renesas,r8a7790-cmt1" for the 48-bit CMT1 device included in r8a7790.
     - "renesas,r8a7791-cmt0" for the 32-bit CMT0 device included in r8a7791.

Documentation/devicetree/bindings/timer/renesas,tmu.txt

@@ -10,6 +10,7 @@ Required Properties:
 
   - compatible: must contain one or more of the following:
     - "renesas,tmu-r8a7740" for the r8a7740 TMU
+    - "renesas,tmu-r8a774c0" for the r8a774C0 TMU
     - "renesas,tmu-r8a7778" for the r8a7778 TMU
     - "renesas,tmu-r8a7779" for the r8a7779 TMU
     - "renesas,tmu-r8a77970" for the r8a77970 TMU

drivers/clocksource/Kconfig

@@ -131,7 +131,8 @@ config SUN5I_HSTIMER
 config TEGRA_TIMER
 	bool "Tegra timer driver" if COMPILE_TEST
 	select CLKSRC_MMIO
-	depends on ARM
+	select TIMER_OF
+	depends on ARM || ARM64
 	help
 	  Enables support for the Tegra driver.
 
@@ -360,6 +361,16 @@ config ARM64_ERRATUM_858921
 	  The workaround will be dynamically enabled when an affected
 	  core is detected.
 
+config SUN50I_ERRATUM_UNKNOWN1
+	bool "Workaround for Allwinner A64 erratum UNKNOWN1"
+	default y
+	depends on ARM_ARCH_TIMER && ARM64 && ARCH_SUNXI
+	select ARM_ARCH_TIMER_OOL_WORKAROUND
+	help
+	  This option enables a workaround for instability in the timer on
+	  the Allwinner A64 SoC. The workaround will only be active if the
+	  allwinner,erratum-unknown1 property is found in the timer node.
+
 config ARM_GLOBAL_TIMER
 	bool "Support for the ARM global timer" if COMPILE_TEST
 	select TIMER_OF if OF

drivers/clocksource/Makefile

@@ -6,7 +6,7 @@ obj-$(CONFIG_ATMEL_ST)		+= timer-atmel-st.o
 obj-$(CONFIG_ATMEL_TCB_CLKSRC)	+= tcb_clksrc.o
 obj-$(CONFIG_X86_PM_TIMER)	+= acpi_pm.o
 obj-$(CONFIG_SCx200HR_TIMER)	+= scx200_hrt.o
-obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC)	+= cs5535-clockevt.o
+obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC)	+= timer-cs5535.o
 obj-$(CONFIG_CLKSRC_JCORE_PIT)		+= jcore-pit.o
 obj-$(CONFIG_SH_TIMER_CMT)	+= sh_cmt.o
 obj-$(CONFIG_SH_TIMER_MTU2)	+= sh_mtu2.o
@@ -29,7 +29,7 @@ obj-$(CONFIG_BCM2835_TIMER)	+= bcm2835_timer.o
 obj-$(CONFIG_CLPS711X_TIMER)	+= clps711x-timer.o
 obj-$(CONFIG_ATLAS7_TIMER)	+= timer-atlas7.o
 obj-$(CONFIG_MXS_TIMER)		+= mxs_timer.o
-obj-$(CONFIG_CLKSRC_PXA)	+= pxa_timer.o
+obj-$(CONFIG_CLKSRC_PXA)	+= timer-pxa.o
 obj-$(CONFIG_PRIMA2_TIMER)	+= timer-prima2.o
 obj-$(CONFIG_U300_TIMER)	+= timer-u300.o
 obj-$(CONFIG_SUN4I_TIMER)	+= timer-sun4i.o
@@ -69,7 +69,7 @@ obj-$(CONFIG_KEYSTONE_TIMER)		+= timer-keystone.o
 obj-$(CONFIG_INTEGRATOR_AP_TIMER)	+= timer-integrator-ap.o
 obj-$(CONFIG_CLKSRC_VERSATILE)		+= timer-versatile.o
 obj-$(CONFIG_CLKSRC_MIPS_GIC)		+= mips-gic-timer.o
-obj-$(CONFIG_CLKSRC_TANGO_XTAL)		+= tango_xtal.o
+obj-$(CONFIG_CLKSRC_TANGO_XTAL)		+= timer-tango-xtal.o
 obj-$(CONFIG_CLKSRC_IMX_GPT)		+= timer-imx-gpt.o
 obj-$(CONFIG_CLKSRC_IMX_TPM)		+= timer-imx-tpm.o
 obj-$(CONFIG_ASM9260_TIMER)		+= asm9260_timer.o

drivers/clocksource/arm_arch_timer.c

@@ -326,6 +326,48 @@ static u64 notrace arm64_1188873_read_cntvct_el0(void)
 }
 #endif
 
+#ifdef CONFIG_SUN50I_ERRATUM_UNKNOWN1
+/*
+ * The low bits of the counter registers are indeterminate while bit 10 or
+ * greater is rolling over. Since the counter value can jump both backward
+ * (7ff -> 000 -> 800) and forward (7ff -> fff -> 800), ignore register values
+ * with all ones or all zeros in the low bits. Bound the loop by the maximum
+ * number of CPU cycles in 3 consecutive 24 MHz counter periods.
+ */
+#define __sun50i_a64_read_reg(reg) ({					\
+	u64 _val;							\
+	int _retries = 150;						\
+									\
+	do {								\
+		_val = read_sysreg(reg);				\
+		_retries--;						\
+	} while (((_val + 1) & GENMASK(9, 0)) <= 1 && _retries);	\
+									\
+	WARN_ON_ONCE(!_retries);					\
+	_val;								\
+})
+
+static u64 notrace sun50i_a64_read_cntpct_el0(void)
+{
+	return __sun50i_a64_read_reg(cntpct_el0);
+}
+
+static u64 notrace sun50i_a64_read_cntvct_el0(void)
+{
+	return __sun50i_a64_read_reg(cntvct_el0);
+}
+
+static u32 notrace sun50i_a64_read_cntp_tval_el0(void)
+{
+	return read_sysreg(cntp_cval_el0) - sun50i_a64_read_cntpct_el0();
+}
+
+static u32 notrace sun50i_a64_read_cntv_tval_el0(void)
+{
+	return read_sysreg(cntv_cval_el0) - sun50i_a64_read_cntvct_el0();
+}
+#endif
+
 #ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
 DEFINE_PER_CPU(const struct arch_timer_erratum_workaround *, timer_unstable_counter_workaround);
 EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround);
@@ -423,6 +465,19 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = {
 		.read_cntvct_el0 = arm64_1188873_read_cntvct_el0,
 	},
 #endif
+#ifdef CONFIG_SUN50I_ERRATUM_UNKNOWN1
+	{
+		.match_type = ate_match_dt,
+		.id = "allwinner,erratum-unknown1",
+		.desc = "Allwinner erratum UNKNOWN1",
+		.read_cntp_tval_el0 = sun50i_a64_read_cntp_tval_el0,
+		.read_cntv_tval_el0 = sun50i_a64_read_cntv_tval_el0,
+		.read_cntpct_el0 = sun50i_a64_read_cntpct_el0,
+		.read_cntvct_el0 = sun50i_a64_read_cntvct_el0,
+		.set_next_event_phys = erratum_set_next_event_tval_phys,
+		.set_next_event_virt = erratum_set_next_event_tval_virt,
+	},
+#endif
 };
 
 typedef bool (*ate_match_fn_t)(const struct arch_timer_erratum_workaround *,

drivers/clocksource/exynos_mct.c

@@ -10,14 +10,12 @@
  * published by the Free Software Foundation.
 */
 
-#include <linux/sched.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/clockchips.h>
 #include <linux/cpu.h>
-#include <linux/platform_device.h>
 #include <linux/delay.h>
 #include <linux/percpu.h>
 #include <linux/of.h>
@@ -388,6 +386,13 @@ static void exynos4_mct_tick_start(unsigned long cycles,
 	exynos4_mct_write(tmp, mevt->base + MCT_L_TCON_OFFSET);
 }
 
+static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
+{
+	/* Clear the MCT tick interrupt */
+	if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1)
+		exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
+}
+
 static int exynos4_tick_set_next_event(unsigned long cycles,
 				       struct clock_event_device *evt)
 {
@@ -404,6 +409,7 @@ static int set_state_shutdown(struct clock_event_device *evt)
 
 	mevt = container_of(evt, struct mct_clock_event_device, evt);
 	exynos4_mct_tick_stop(mevt);
+	exynos4_mct_tick_clear(mevt);
 	return 0;
 }
 
@@ -420,8 +426,11 @@ static int set_state_periodic(struct clock_event_device *evt)
 	return 0;
 }
 
-static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
+static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
 {
+	struct mct_clock_event_device *mevt = dev_id;
+	struct clock_event_device *evt = &mevt->evt;
+
 	/*
 	 * This is for supporting oneshot mode.
 	 * Mct would generate interrupt periodically
@@ -430,16 +439,6 @@ static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
 	if (!clockevent_state_periodic(&mevt->evt))
 		exynos4_mct_tick_stop(mevt);
 
-	/* Clear the MCT tick interrupt */
-	if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1)
-		exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
-}
-
-static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
-{
-	struct mct_clock_event_device *mevt = dev_id;
-	struct clock_event_device *evt = &mevt->evt;
-
 	exynos4_mct_tick_clear(mevt);
 
 	evt->event_handler(evt);
@@ -507,13 +506,12 @@ static int __init exynos4_timer_resources(struct device_node *np, void __iomem *
 	int err, cpu;
 	struct clk *mct_clk, *tick_clk;
 
-	tick_clk = np ? of_clk_get_by_name(np, "fin_pll") :
-				clk_get(NULL, "fin_pll");
+	tick_clk = of_clk_get_by_name(np, "fin_pll");
 	if (IS_ERR(tick_clk))
 		panic("%s: unable to determine tick clock rate\n", __func__);
 	clk_rate = clk_get_rate(tick_clk);
 
-	mct_clk = np ? of_clk_get_by_name(np, "mct") : clk_get(NULL, "mct");
+	mct_clk = of_clk_get_by_name(np, "mct");
 	if (IS_ERR(mct_clk))
 		panic("%s: unable to retrieve mct clock instance\n", __func__);
 	clk_prepare_enable(mct_clk);
@@ -562,7 +560,19 @@ static int __init exynos4_timer_resources(struct device_node *np, void __iomem *
 	return 0;
 
 out_irq:
-	free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
+	if (mct_int_type == MCT_INT_PPI) {
+		free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
+	} else {
+		for_each_possible_cpu(cpu) {
+			struct mct_clock_event_device *pcpu_mevt =
+				per_cpu_ptr(&percpu_mct_tick, cpu);
+
+			if (pcpu_mevt->evt.irq != -1) {
+				free_irq(pcpu_mevt->evt.irq, pcpu_mevt);
+				pcpu_mevt->evt.irq = -1;
+			}
+		}
+	}
 	return err;
 }
 
@@ -581,11 +591,7 @@ static int __init mct_init_dt(struct device_node *np, unsigned int int_type)
 	 * timer irqs are specified after the four global timer
 	 * irqs are specified.
 	 */
-#ifdef CONFIG_OF
 	nr_irqs = of_irq_count(np);
-#else
-	nr_irqs = 0;
-#endif
 	for (i = MCT_L0_IRQ; i < nr_irqs; i++)
 		mct_irqs[i] = irq_of_parse_and_map(np, i);
 

drivers/clocksource/timer-riscv.c

@@ -95,13 +95,30 @@ static int __init riscv_timer_init_dt(struct device_node *n)
 	struct clocksource *cs;
 
 	hartid = riscv_of_processor_hartid(n);
+	if (hartid < 0) {
+		pr_warn("Not valid hartid for node [%pOF] error = [%d]\n",
+			n, hartid);
+		return hartid;
+	}
+
 	cpuid = riscv_hartid_to_cpuid(hartid);
+	if (cpuid < 0) {
+		pr_warn("Invalid cpuid for hartid [%d]\n", hartid);
+		return cpuid;
+	}
 
 	if (cpuid != smp_processor_id())
 		return 0;
 
+	pr_info("%s: Registering clocksource cpuid [%d] hartid [%d]\n",
+	       __func__, cpuid, hartid);
 	cs = per_cpu_ptr(&riscv_clocksource, cpuid);
-	clocksource_register_hz(cs, riscv_timebase);
+	error = clocksource_register_hz(cs, riscv_timebase);
+	if (error) {
+		pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
+		       error, cpuid);
+		return error;
+	}
 
 	sched_clock_register(riscv_sched_clock,
 			BITS_PER_LONG, riscv_timebase);
@@ -110,8 +127,8 @@ static int __init riscv_timer_init_dt(struct device_node *n)
 			 "clockevents/riscv/timer:starting",
 			 riscv_timer_starting_cpu, riscv_timer_dying_cpu);
 	if (error)
-		pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
-		       error, cpuid);
+		pr_err("cpu hp setup state failed for RISCV timer [%d]\n",
+		       error);
 	return error;
 }
 

drivers/clocksource/timer-sun5i.c

@@ -202,6 +202,11 @@ static int __init sun5i_setup_clocksource(struct device_node *node,
 	}
 
 	rate = clk_get_rate(clk);
+	if (!rate) {
+		pr_err("Couldn't get parent clock rate\n");
+		ret = -EINVAL;
+		goto err_disable_clk;
+	}
 
 	cs->timer.base = base;
 	cs->timer.clk = clk;
@@ -275,6 +280,11 @@ static int __init sun5i_setup_clockevent(struct device_node *node, void __iomem
 	}
 
 	rate = clk_get_rate(clk);
+	if (!rate) {
+		pr_err("Couldn't get parent clock rate\n");
+		ret = -EINVAL;
+		goto err_disable_clk;
+	}
 
 	ce->timer.base = base;
 	ce->timer.ticks_per_jiffy = DIV_ROUND_UP(rate, HZ);

drivers/soc/tegra/Kconfig

@@ -76,6 +76,7 @@ config ARCH_TEGRA_210_SOC
 	select PINCTRL_TEGRA210
 	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
+	select TEGRA_TIMER
 	help
 	  Enable support for the NVIDIA Tegra210 SoC. Also known as Tegra X1,
 	  the Tegra210 has four Cortex-A57 cores paired with four Cortex-A53

include/linux/cpuhotplug.h

@@ -121,6 +121,7 @@ enum cpuhp_state {
 	CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
 	CPUHP_AP_ARM_TWD_STARTING,
 	CPUHP_AP_QCOM_TIMER_STARTING,
+	CPUHP_AP_TEGRA_TIMER_STARTING,
 	CPUHP_AP_ARMADA_TIMER_STARTING,
 	CPUHP_AP_MARCO_TIMER_STARTING,
 	CPUHP_AP_MIPS_GIC_TIMER_STARTING,

include/linux/posix-timers.h

@@ -12,7 +12,7 @@ struct siginfo;
 
 struct cpu_timer_list {
 	struct list_head entry;
-	u64 expires, incr;
+	u64 expires;
 	struct task_struct *task;
 	int firing;
 };

kernel/rcu/Kconfig

@@ -87,36 +87,6 @@ config RCU_STALL_COMMON
 config RCU_NEED_SEGCBLIST
 	def_bool ( TREE_RCU || PREEMPT_RCU || TREE_SRCU )
 
-config CONTEXT_TRACKING
-       bool
-
-config CONTEXT_TRACKING_FORCE
-	bool "Force context tracking"
-	depends on CONTEXT_TRACKING
-	default y if !NO_HZ_FULL
-	help
-	  The major pre-requirement for full dynticks to work is to
-	  support the context tracking subsystem. But there are also
-	  other dependencies to provide in order to make the full
-	  dynticks working.
-
-	  This option stands for testing when an arch implements the
-	  context tracking backend but doesn't yet fullfill all the
-	  requirements to make the full dynticks feature working.
-	  Without the full dynticks, there is no way to test the support
-	  for context tracking and the subsystems that rely on it: RCU
-	  userspace extended quiescent state and tickless cputime
-	  accounting. This option copes with the absence of the full
-	  dynticks subsystem by forcing the context tracking on all
-	  CPUs in the system.
-
-	  Say Y only if you're working on the development of an
-	  architecture backend for the context tracking.
-
-	  Say N otherwise, this option brings an overhead that you
-	  don't want in production.
-
-
 config RCU_FANOUT
 	int "Tree-based hierarchical RCU fanout value"
 	range 2 64 if 64BIT

kernel/time/Kconfig

@@ -117,6 +117,35 @@ config NO_HZ_FULL
 
 endchoice
 
+config CONTEXT_TRACKING
+       bool
+
+config CONTEXT_TRACKING_FORCE
+	bool "Force context tracking"
+	depends on CONTEXT_TRACKING
+	default y if !NO_HZ_FULL
+	help
+	  The major pre-requirement for full dynticks to work is to
+	  support the context tracking subsystem. But there are also
+	  other dependencies to provide in order to make the full
+	  dynticks working.
+
+	  This option stands for testing when an arch implements the
+	  context tracking backend but doesn't yet fullfill all the
+	  requirements to make the full dynticks feature working.
+	  Without the full dynticks, there is no way to test the support
+	  for context tracking and the subsystems that rely on it: RCU
+	  userspace extended quiescent state and tickless cputime
+	  accounting. This option copes with the absence of the full
+	  dynticks subsystem by forcing the context tracking on all
+	  CPUs in the system.
+
+	  Say Y only if you're working on the development of an
+	  architecture backend for the context tracking.
+
+	  Say N otherwise, this option brings an overhead that you
+	  don't want in production.
+
 config NO_HZ
 	bool "Old Idle dynticks config"
 	depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS

kernel/time/hrtimer.c

@@ -364,7 +364,7 @@ static bool hrtimer_fixup_activate(void *addr, enum debug_obj_state state)
 	switch (state) {
 	case ODEBUG_STATE_ACTIVE:
 		WARN_ON(1);
-
+		/* fall through */
 	default:
 		return false;
 	}

kernel/time/posix-cpu-timers.c

@@ -67,13 +67,13 @@ static void bump_cpu_timer(struct k_itimer *timer, u64 now)
 	int i;
 	u64 delta, incr;
 
-	if (timer->it.cpu.incr == 0)
+	if (!timer->it_interval)
 		return;
 
 	if (now < timer->it.cpu.expires)
 		return;
 
-	incr = timer->it.cpu.incr;
+	incr = timer->it_interval;
 	delta = now + incr - timer->it.cpu.expires;
 
 	/* Don't use (incr*2 < delta), incr*2 might overflow. */
@@ -520,7 +520,7 @@ static void cpu_timer_fire(struct k_itimer *timer)
 		 */
 		wake_up_process(timer->it_process);
 		timer->it.cpu.expires = 0;
-	} else if (timer->it.cpu.incr == 0) {
+	} else if (!timer->it_interval) {
 		/*
 		 * One-shot timer.  Clear it as soon as it's fired.
 		 */
@@ -606,7 +606,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 	 */
 
 	ret = 0;
-	old_incr = timer->it.cpu.incr;
+	old_incr = timer->it_interval;
 	old_expires = timer->it.cpu.expires;
 	if (unlikely(timer->it.cpu.firing)) {
 		timer->it.cpu.firing = -1;
@@ -684,8 +684,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 	 * Install the new reload setting, and
 	 * set up the signal and overrun bookkeeping.
 	 */
-	timer->it.cpu.incr = timespec64_to_ns(&new->it_interval);
-	timer->it_interval = ns_to_ktime(timer->it.cpu.incr);
+	timer->it_interval = timespec64_to_ktime(new->it_interval);
 
 	/*
 	 * This acts as a modification timestamp for the timer,
@@ -724,7 +723,7 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *itp
 	/*
 	 * Easy part: convert the reload time.
 	 */
-	itp->it_interval = ns_to_timespec64(timer->it.cpu.incr);
+	itp->it_interval = ktime_to_timespec64(timer->it_interval);
 
 	if (!timer->it.cpu.expires)
 		return;

kernel/time/tick-broadcast.c

@@ -375,6 +375,7 @@ void tick_broadcast_control(enum tick_broadcast_mode mode)
 	switch (mode) {
 	case TICK_BROADCAST_FORCE:
 		tick_broadcast_forced = 1;
+		/* fall through */
 	case TICK_BROADCAST_ON:
 		cpumask_set_cpu(cpu, tick_broadcast_on);
 		if (!cpumask_test_and_set_cpu(cpu, tick_broadcast_mask)) {

kernel/time/timekeeping_debug.c

@@ -37,15 +37,8 @@ DEFINE_SHOW_ATTRIBUTE(tk_debug_sleep_time);
 
 static int __init tk_debug_sleep_time_init(void)
 {
-	struct dentry *d;
-
-	d = debugfs_create_file("sleep_time", 0444, NULL, NULL,
-		&tk_debug_sleep_time_fops);
-	if (!d) {
-		pr_err("Failed to create sleep_time debug file\n");
-		return -ENOMEM;
-	}
-
+	debugfs_create_file("sleep_time", 0444, NULL, NULL,
+			    &tk_debug_sleep_time_fops);
 	return 0;
 }
 late_initcall(tk_debug_sleep_time_init);

kernel/time/timer.c

@@ -647,7 +647,7 @@ static bool timer_fixup_activate(void *addr, enum debug_obj_state state)
 
 	case ODEBUG_STATE_ACTIVE:
 		WARN_ON(1);
-
+		/* fall through */
 	default:
 		return false;
 	}