Message-ID: <CAJM55Z8U5ddBg_T34rHYUXQcTLdzhMhbhv3mZxehQL8VLBFtUA@mail.gmail.com>
Date: Tue, 30 Apr 2024 05:18:51 -0500
From: Emil Renner Berthing <emil.renner.berthing@...onical.com>
To: Ziv Xu <ziv.xu@...rfivetech.com>, Daniel Lezcano <daniel.lezcano@...aro.org>, 
	Thomas Gleixner <tglx@...utronix.de>
Cc: "linux-riscv@...ts.infradead.org" <linux-riscv@...ts.infradead.org>, 
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>, Rob Herring <robh+dt@...nel.org>, 
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>, 
	Paul Walmsley <paul.walmsley@...ive.com>, Palmer Dabbelt <palmer@...belt.com>, 
	Albert Ou <aou@...s.berkeley.edu>, Philipp Zabel <p.zabel@...gutronix.de>, 
	Walker Chen <walker.chen@...rfivetech.com>, Xingyu Wu <xingyu.wu@...rfivetech.com>, 
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, Conor Dooley <conor@...nel.org>
Subject: Re: 回复: [PATCH v10 2/3] clocksource: Add JH7110 timer driver

Ziv Xu wrote:
>
>
> > -----邮件原件-----
> > 发件人: Ziv Xu
> > 发送时间: 2024年4月12日 16:46
> > 收件人: Daniel Lezcano <daniel.lezcano@...aro.org>; Thomas Gleixner
> > <tglx@...utronix.de>; Emil Renner Berthing
> > <emil.renner.berthing@...onical.com>; Christophe JAILLET
> > <christophe.jaillet@...adoo.fr>
> > 抄送: linux-riscv@...ts.infradead.org; devicetree@...r.kernel.org; Rob Herring
> > <robh+dt@...nel.org>; Krzysztof Kozlowski
> > <krzysztof.kozlowski+dt@...aro.org>; Paul Walmsley
> > <paul.walmsley@...ive.com>; Palmer Dabbelt <palmer@...belt.com>; Albert
> > Ou <aou@...s.berkeley.edu>; Philipp Zabel <p.zabel@...gutronix.de>; Walker
> > Chen <walker.chen@...rfivetech.com>; Xingyu Wu
> > <xingyu.wu@...rfivetech.com>; linux-kernel@...r.kernel.org; Conor Dooley
> > <conor@...nel.org>
> > 主题: [PATCH v10 2/3] clocksource: Add JH7110 timer driver
> >
> > From: Xingyu Wu <xingyu.wu@...rfivetech.com>
> >
> > Add timer driver for the StarFive JH7110 SoC.
> >
> > This timer has four free-running and independent 32-bit counters.
> > Each channel(counter) can trigger an interrupt when timeout even CPU is
> > sleeping. So this timer is used as global timer and register clockevent for each
> > CPU core after riscv-timer registration on the StarFive JH7110 SoC.
> >
> > Signed-off-by: Ziv Xu <ziv.xu@...rfivetech.com>
> > Signed-off-by: Xingyu Wu <xingyu.wu@...rfivetech.com>
> > ---
> >  MAINTAINERS                        |   7 +
> >  drivers/clocksource/Kconfig        |  11 +
> >  drivers/clocksource/Makefile       |   1 +
> >  drivers/clocksource/timer-jh7110.c | 345 +++++++++++++++++++++++++++++
> >  include/linux/cpuhotplug.h         |   1 +
> >  5 files changed, 365 insertions(+)
> >  create mode 100644 drivers/clocksource/timer-jh7110.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 7c121493f43d..ef9b5f5bad9e 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -21043,6 +21043,13 @@ S:	Maintained
> >  F:	Documentation/devicetree/bindings/sound/starfive,jh7110-tdm.yaml
> >  F:	sound/soc/starfive/jh7110_tdm.c
> >
> > +STARFIVE JH7110 TIMER DRIVER
> > +M:	Samin Guo <samin.guo@...rfivetech.com>
> > +M:	Xingyu Wu <xingyu.wu@...rfivetech.com>
> > +S:	Supported
> > +F:	Documentation/devicetree/bindings/timer/starfive,jh7110-timer.yaml
> > +F:	drivers/clocksource/timer-jh7110.c
> > +
> >  STARFIVE JH71X0 CLOCK DRIVERS
> >  M:	Emil Renner Berthing <kernel@...il.dk>
> >  M:	Hal Feng <hal.feng@...rfivetech.com>
> > diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index
> > 34faa0320ece..2dc97201dee1 100644
> > --- a/drivers/clocksource/Kconfig
> > +++ b/drivers/clocksource/Kconfig
> > @@ -641,6 +641,17 @@ config RISCV_TIMER
> >  	  is accessed via both the SBI and the rdcycle instruction.  This is
> >  	  required for all RISC-V systems.
> >
> > +config STARFIVE_JH7110_TIMER
> > +	bool "Timer for the STARFIVE JH7110 SoC"
> > +	depends on ARCH_STARFIVE || COMPILE_TEST
> > +	select TIMER_OF
> > +	select CLKSRC_MMIO
> > +	default ARCH_STARFIVE
> > +	help
> > +	  This enables the timer for StarFive JH7110 SoC. On RISC-V platform,
> > +	  the system has started RISCV_TIMER, but you can also use this timer
> > +	  which can provide four channels to do a lot more things on JH7110 SoC.
> > +
> >  config CLINT_TIMER
> >  	bool "CLINT Timer for the RISC-V platform" if COMPILE_TEST
> >  	depends on GENERIC_SCHED_CLOCK && RISCV diff --git
> > a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index
> > 4bb856e4df55..8dc2f0ea2d0f 100644
> > --- a/drivers/clocksource/Makefile
> > +++ b/drivers/clocksource/Makefile
> > @@ -80,6 +80,7 @@ obj-$(CONFIG_INGENIC_TIMER)		+= ingenic-timer.o
> >  obj-$(CONFIG_CLKSRC_ST_LPC)		+= clksrc_st_lpc.o
> >  obj-$(CONFIG_X86_NUMACHIP)		+= numachip.o
> >  obj-$(CONFIG_RISCV_TIMER)		+= timer-riscv.o
> > +obj-$(CONFIG_STARFIVE_JH7110_TIMER)	+= timer-jh7110.o
> >  obj-$(CONFIG_CLINT_TIMER)		+= timer-clint.o
> >  obj-$(CONFIG_CSKY_MP_TIMER)		+= timer-mp-csky.o
> >  obj-$(CONFIG_GX6605S_TIMER)		+= timer-gx6605s.o
> > diff --git a/drivers/clocksource/timer-jh7110.c
> > b/drivers/clocksource/timer-jh7110.c
> > new file mode 100644
> > index 000000000000..dc770507f209
> > --- /dev/null
> > +++ b/drivers/clocksource/timer-jh7110.c
> > @@ -0,0 +1,345 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Starfive JH7110 Timer driver
> > + *
> > + * Copyright (C) 2023 StarFive Technology Co., Ltd.
> > + *
> > + * This timer has four free-running and independent 32-bit counters and
> > +runs in 24MHz
> > + * clock on the StarFive JH7110 SoC. Each channel(counter) can trigger
> > +an interrupt
> > + * when timeout even CPU is sleeping. They support one-shot mode and
> > continuous-run mode.
> > + *
> > + * Each channel is used as a global timer that serves each cpu core:
> > + * JH7110 Timer Channel 0 -- CPU 0
> > + * JH7110 Timer Channel 1 -- CPU 1
> > + * JH7110 Timer Channel 2 -- CPU 2
> > + * JH7110 Timer Channel 3 -- CPU 3
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/clockchips.h>
> > +#include <linux/cpu.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/irq.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/reset.h>
> > +
> > +/* Bias: Ch0-0x0, Ch1-0x40, Ch2-0x80, and so on. */
> > +#define JH7110_TIMER_CH_LEN		0x40
> > +#define JH7110_TIMER_CH_BASE(x)		((x) * JH7110_TIMER_CH_LEN)
> > +#define JH7110_TIMER_CH_MAX		4
> > +
> > +#define JH7110_DELAY_US			0
> > +#define JH7110_TIMEOUT_US		10000
> > +#define JH7110_CLOCKEVENT_RATING	300
> > +#define JH7110_TIMER_MAX_TICKS		0xffffffff
> > +#define JH7110_TIMER_MIN_TICKS		0xf
> > +
> > +#define JH7110_TIMER_INT_STATUS		0x00 /* RO[0:4]: Interrupt Status
> > for channel0~4 */
> > +#define JH7110_TIMER_CTL		0x04 /* RW[0]: 0-continuous run, 1-single run
> > */
> > +#define JH7110_TIMER_LOAD		0x08 /* RW: load value to counter */
> > +#define JH7110_TIMER_ENABLE		0x10 /* RW[0]: timer enable register */
> > +#define JH7110_TIMER_RELOAD		0x14 /* RW: write 1 or 0 both reload
> > counter */
> > +#define JH7110_TIMER_VALUE		0x18 /* RO: timer value register */
> > +#define JH7110_TIMER_INT_CLR		0x20 /* RW: timer interrupt clear
> > register */
> > +#define JH7110_TIMER_INT_MASK		0x24 /* RW[0]: timer interrupt
> > mask register */
> > +
> > +#define JH7110_TIMER_INT_CLR_ENA	BIT(0)
> > +#define JH7110_TIMER_INT_CLR_AVA_MASK	BIT(1)
> > +
> > +#define JH7110_PERCPU_GET_CLKEVT
> > 	(&jh7110_timer_info.clkevt[smp_processor_id()])
> > +
> > +/**
> > + * struct jh7110_clkevt - Description of each timer channel
> > + * @clk:		Clock of each timer channel
> > + * @rst:		Reset of each timer channel
> > + * @base:		Virtual address of each timer channel
> > + * @irq:                Interrupt number of each timer channel
> > + * @timer_enabled:      Enabled flag for each timer channel
> > + * @name:		Name of each timer channel
> > + */
> > +struct jh7110_clkevt {
> > +	struct clk		*clk;
> > +	struct reset_control	*rst;
> > +	void __iomem		*base;
> > +	int			irq;
> > +	bool			timer_enabled;
> > +	char			name[sizeof("jh7110-timer.chX")];
> > +};
> > +
> > +struct jh7110_timer_priv {
> > +	struct clk		*pclk;
> > +	struct reset_control	*prst;
> > +	struct device		*dev;
> > +	struct jh7110_clkevt	clkevt[JH7110_TIMER_CH_MAX];
> > +};
> > +
> > +static struct jh7110_timer_priv jh7110_timer_info;
> > +
> > +/* 0:continuous-run mode, 1:single-run mode */ enum jh7110_timer_mode {
> > +	JH7110_TIMER_MODE_CONTIN,
> > +	JH7110_TIMER_MODE_SINGLE,
> > +};
> > +
> > +/* Interrupt Mask, 0:Unmask, 1:Mask */
> > +enum jh7110_timer_int_mask {
> > +	JH7110_TIMER_INT_ENA,
> > +	JH7110_TIMER_INT_DIS,
> > +};
> > +
> > +enum jh7110_timer_enable {
> > +	JH7110_TIMER_DIS,
> > +	JH7110_TIMER_ENA,
> > +};
> > +
> > +/*
> > + * BIT(0): Read value represent channel int status.
> > + * Write 1 to this bit to clear interrupt. Write 0 has no effects.
> > + * BIT(1): "1" means that it is clearing interrupt. BIT(0) can not be written.
> > + */
> > +static inline int jh7110_timer_int_clear(struct jh7110_clkevt *clkevt)
> > +{
> > +	u32 value;
> > +	int ret;
> > +
> > +	/* Waiting interrupt can be cleared */
> > +	ret = readl_poll_timeout_atomic(clkevt->base + JH7110_TIMER_INT_CLR,
> > value,
> > +					!(value & JH7110_TIMER_INT_CLR_AVA_MASK),
> > +					JH7110_DELAY_US, JH7110_TIMEOUT_US);
> > +	if (!ret)
> > +		writel(JH7110_TIMER_INT_CLR_ENA, clkevt->base +
> > +JH7110_TIMER_INT_CLR);
> > +
> > +	return ret;
> > +}
> > +
> > +static int jh7110_timer_start(struct jh7110_clkevt *clkevt) {
> > +	int ret;
> > +
> > +	/* Disable and clear interrupt first */
> > +	writel(JH7110_TIMER_INT_DIS, clkevt->base +
> > JH7110_TIMER_INT_MASK);
> > +	ret = jh7110_timer_int_clear(clkevt);
> > +
> > +	writel(JH7110_TIMER_INT_ENA, clkevt->base +
> > JH7110_TIMER_INT_MASK);
> > +	writel(JH7110_TIMER_ENA, clkevt->base + JH7110_TIMER_ENABLE);
> > +
> > +	return ret;
> > +}
> > +
> > +static int jh7110_timer_shutdown(struct clock_event_device *evt) {
> > +	struct jh7110_clkevt *clkevt = JH7110_PERCPU_GET_CLKEVT;
> > +
> > +	writel(JH7110_TIMER_DIS, clkevt->base + JH7110_TIMER_ENABLE);
> > +	return jh7110_timer_int_clear(clkevt); }
> > +
> > +/* IRQ handler for the timer */
> > +static irqreturn_t jh7110_timer_interrupt(int irq, void *data) {
> > +	struct clock_event_device *evt = (struct clock_event_device *)data;
> > +	struct jh7110_clkevt *clkevt = &jh7110_timer_info.clkevt[0];
> > +	u32 reg = readl(clkevt->base + JH7110_TIMER_INT_STATUS);
> > +	u8 cpu_id = smp_processor_id();
> > +
> > +	/* Check interrupt status and channel(cpu) ID */
> > +	if (!(reg & BIT(cpu_id)))
> > +		return IRQ_NONE;
> > +
> > +	clkevt = &jh7110_timer_info.clkevt[cpu_id];
> > +	writel(JH7110_TIMER_INT_CLR_ENA, (clkevt->base +
> > +JH7110_TIMER_INT_CLR));
> > +
> > +	if (evt->event_handler)
> > +		evt->event_handler(evt);
> > +
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +static int jh7110_timer_set_periodic(struct clock_event_device *evt) {
> > +	struct jh7110_clkevt *clkevt = JH7110_PERCPU_GET_CLKEVT;
> > +
> > +	writel(JH7110_TIMER_MODE_CONTIN, clkevt->base +
> > JH7110_TIMER_CTL);
> > +	return 0;
> > +}
> > +
> > +static int jh7110_timer_set_oneshot(struct clock_event_device *evt) {
> > +	struct jh7110_clkevt *clkevt = JH7110_PERCPU_GET_CLKEVT;
> > +
> > +	writel(JH7110_TIMER_MODE_SINGLE, clkevt->base +
> > JH7110_TIMER_CTL);
> > +	return 0;
> > +}
> > +
> > +static int jh7110_timer_set_next_event(unsigned long next,
> > +				       struct clock_event_device *evt) {
> > +	struct jh7110_clkevt *clkevt = JH7110_PERCPU_GET_CLKEVT;
> > +
> > +	writel(JH7110_TIMER_MODE_SINGLE, clkevt->base +
> > JH7110_TIMER_CTL);
> > +	writel(next, clkevt->base + JH7110_TIMER_LOAD);
> > +
> > +	return jh7110_timer_start(clkevt);
> > +}
> > +
> > +static DEFINE_PER_CPU(struct clock_event_device, jh7110_clock_event) = {
> > +	.features			= CLOCK_EVT_FEAT_PERIODIC |
> > +					  CLOCK_EVT_FEAT_ONESHOT,
> > +	.rating				= JH7110_CLOCKEVENT_RATING,
> > +	.set_state_shutdown		= jh7110_timer_shutdown,
> > +	.set_state_periodic		= jh7110_timer_set_periodic,
> > +	.set_state_oneshot		= jh7110_timer_set_oneshot,
> > +	.set_state_oneshot_stopped	= jh7110_timer_shutdown,
> > +	.set_next_event			= jh7110_timer_set_next_event,
> > +};
> > +
> > +static int jh7110_timer_dying_cpu(unsigned int cpu) {
> > +	struct jh7110_timer_priv *priv = &jh7110_timer_info;
> > +
> > +	if (!priv->clkevt[cpu].timer_enabled)
> > +		return 0;
> > +
> > +	writel(JH7110_TIMER_DIS, priv->clkevt[cpu].base +
> > JH7110_TIMER_ENABLE);
> > +	jh7110_timer_int_clear(&priv->clkevt[cpu]);
> > +	reset_control_assert(priv->clkevt[cpu].rst);
> > +	clk_disable_unprepare(priv->clkevt[cpu].clk);
> > +
> > +	return 0;
> > +}
> > +
> > +static int jh7110_timer_starting_cpu(unsigned int cpu) {
> > +	struct clock_event_device *evt = per_cpu_ptr(&jh7110_clock_event, cpu);
> > +	struct jh7110_timer_priv *priv = &jh7110_timer_info;
> > +	int err;
> > +	u32 rate;
> > +
> > +	if (cpu >= JH7110_TIMER_CH_MAX)
> > +		return -ENOMEM;
> > +
> > +	err = clk_prepare_enable(priv->clkevt[cpu].clk);
> > +	if (err)
> > +		goto err_starting_cpu;
> > +
> > +	err = reset_control_deassert(priv->clkevt[cpu].rst);
> > +	if (err)
> > +		goto err_soft_reset;
> > +
> > +	rate = clk_get_rate(priv->clkevt[cpu].clk);
> > +	evt->cpumask = cpumask_of(cpu);
> > +	evt->irq = priv->clkevt[cpu].irq;
> > +
> > +	err = irq_force_affinity(evt->irq, cpumask_of(cpu));
> > +	if (err)
> > +		goto err_affinity;
> > +
> > +	clockevents_config_and_register(evt, rate, JH7110_TIMER_MIN_TICKS,
> > +					JH7110_TIMER_MAX_TICKS);
> > +
> > +	/* Use one-shot mode */
> > +	writel(JH7110_TIMER_MODE_SINGLE, (priv->clkevt[cpu].base +
> > +JH7110_TIMER_CTL));
> > +
> > +	priv->clkevt[cpu].timer_enabled = true;
> > +
> > +	err = jh7110_timer_start(&priv->clkevt[cpu]);
> > +	if (err)
> > +		goto err_affinity;
> > +	return 0;
> > +
> > +err_affinity:
> > +	reset_control_assert(priv->clkevt[cpu].rst);
> > +err_soft_reset:
> > +	clk_disable_unprepare(priv->clkevt[cpu].clk);
> > +err_starting_cpu:
> > +	free_irq(evt->irq, evt);
> > +	return err;
> > +}
> > +
> > +static int jh7110_timer_probe(struct platform_device *pdev) {
> > +	struct jh7110_timer_priv *priv = &jh7110_timer_info;
> > +	struct clock_event_device *evt;
> > +	struct jh7110_clkevt *clkevt;
> > +	char name[sizeof("chX")];
> > +	int ch;
> > +	int ret;
> > +	void __iomem *base;
> > +
> > +	base = devm_platform_ioremap_resource(pdev, 0);
> > +	if (IS_ERR(base))
> > +		return dev_err_probe(&pdev->dev, PTR_ERR(base),
> > +				     "failed to map registers\n");
> > +
> > +	priv->prst = devm_reset_control_get_exclusive(&pdev->dev, "apb");
> > +	if (IS_ERR(priv->prst))
> > +		return dev_err_probe(&pdev->dev, PTR_ERR(priv->prst),
> > +				     "failed to get apb reset\n");
> > +
> > +	priv->pclk = devm_clk_get_enabled(&pdev->dev, "apb");
> > +	if (IS_ERR(priv->pclk))
> > +		return dev_err_probe(&pdev->dev, PTR_ERR(priv->pclk),
> > +				     "failed to get & enable apb clock\n");
> > +
> > +	ret = reset_control_deassert(priv->prst);
> > +	if (ret)
> > +		return dev_err_probe(&pdev->dev, ret, "failed to deassert apb
> > +reset\n");
> > +
> > +	for (ch = 0; ch < JH7110_TIMER_CH_MAX; ch++) {
> > +		evt = per_cpu_ptr(&jh7110_clock_event, ch);
> > +		clkevt = &priv->clkevt[ch];
> > +		snprintf(name, sizeof(name), "ch%d", ch);
> > +
> > +		clkevt->base = base + JH7110_TIMER_CH_BASE(ch);
> > +		/* Ensure timer is disabled */
> > +		writel(JH7110_TIMER_DIS, clkevt->base + JH7110_TIMER_ENABLE);
> > +		ret = jh7110_timer_int_clear(clkevt);
> > +		if (ret)
> > +			return ret;
> > +
> > +		clkevt->rst = devm_reset_control_get_exclusive(&pdev->dev, name);
> > +		if (IS_ERR(clkevt->rst))
> > +			return PTR_ERR(clkevt->rst);
> > +
> > +		clkevt->clk = devm_clk_get(&pdev->dev, name);
> > +		if (IS_ERR(clkevt->clk))
> > +			return PTR_ERR(clkevt->clk);
> > +
> > +		clkevt->irq = platform_get_irq(pdev, ch);
> > +		if (clkevt->irq < 0)
> > +			return clkevt->irq;
> > +
> > +		snprintf(clkevt->name, sizeof(clkevt->name), "jh7110-timer.ch%d",
> > ch);
> > +		ret = devm_request_irq(&pdev->dev, clkevt->irq,
> > jh7110_timer_interrupt,
> > +				       IRQF_TIMER | IRQF_IRQPOLL,
> > +				       clkevt->name, evt);
> > +
> > +		if (ret)
> > +			return ret;
> > +
> > +		clkevt->timer_enabled = false;
> > +	}
> > +
> > +	return cpuhp_setup_state(CPUHP_AP_JH7110_TIMER_STARTING,
> > +				"clockevents/jh7110/timer:starting",
> > +				jh7110_timer_starting_cpu, jh7110_timer_dying_cpu); }
> > +
> > +static const struct of_device_id jh7110_timer_match[] = {
> > +	{ .compatible = "starfive,jh7110-timer", },
> > +	{ /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, jh7110_timer_match);
> > +
> > +static struct platform_driver jh7110_timer_driver = {
> > +	.probe = jh7110_timer_probe,
> > +	.driver = {
> > +		.name = "jh7110-timer",
> > +		.of_match_table = jh7110_timer_match,
> > +	},
> > +};
> > +module_platform_driver(jh7110_timer_driver);
> > +
> > +MODULE_AUTHOR("Xingyu Wu <xingyu.wu@...rfivetech.com>");
> > +MODULE_DESCRIPTION("StarFive JH7110 timer driver");
> > +MODULE_LICENSE("GPL");
> > diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index
> > 35e78ddb2b37..4a8b487c327e 100644
> > --- a/include/linux/cpuhotplug.h
> > +++ b/include/linux/cpuhotplug.h
> > @@ -175,6 +175,7 @@ enum cpuhp_state {
> >  	CPUHP_AP_CSKY_TIMER_STARTING,
> >  	CPUHP_AP_TI_GP_TIMER_STARTING,
> >  	CPUHP_AP_HYPERV_TIMER_STARTING,
> > +	CPUHP_AP_JH7110_TIMER_STARTING,
> >  	/* Must be the last timer callback */
> >  	CPUHP_AP_DUMMY_TIMER_STARTING,
> >  	CPUHP_AP_ARM_XEN_STARTING,
> > --
> > 2.17.1
>
> Hi Daniel / Thomas
>
> I have submitted new version of patch for jh7110 timer driver. Could you please help to review and give your comments?
> Thanks a lot!

Hi Ziv

I tried this on 6.9-rc6 on my VF2. It boots, but very slowly and "choppy". That
is it repeatedly runs for <1s and then hangs for about 4s.

Does this patch work for you?

/Emil

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