From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Date: Fri, 20 Mar 2020 14:32:24 -0600 From: Mathieu Poirier Subject: Re: [PATCHv8 14/15] remoteproc/omap: Add watchdog functionality for remote processors Message-ID: <20200320203224.GB16145@xps15> References: <20200313081718.30612-1-t-kristo@ti.com> <20200313081718.30612-15-t-kristo@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200313081718.30612-15-t-kristo@ti.com> To: Tero Kristo Cc: bjorn.andersson@linaro.org, ohad@wizery.com, linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, s-anna@ti.com, afd@ti.com List-ID: On Fri, Mar 13, 2020 at 10:17:17AM +0200, Tero Kristo wrote: > From: Suman Anna > > Remote processors can be stuck in a loop, and may not be recoverable > if they do not have a built-in watchdog. The watchdog implementation > for OMAP remote processors uses external gptimers that can be used > to interrupt both the Linux host as well as the remote processor. > > Each remote processor is responsible for refreshing the timer during > normal behavior - during OS task scheduling or entering the idle loop > properly. During a watchdog condition (executing a tight loop causing > no scheduling), the host processor gets interrupts and schedules a > recovery for the corresponding remote processor. The remote processor > may also get interrupted to be able to print a back trace. > > A menuconfig option has also been added to enable/disable the Watchdog > functionality, with the default as disabled. > > Signed-off-by: Suman Anna > Signed-off-by: Tero Kristo > Reviewed-by: Andrew F. Davis > --- > v8: > - minor cosmetic changes > > drivers/remoteproc/Kconfig | 12 +++ > drivers/remoteproc/omap_remoteproc.c | 152 +++++++++++++++++++++++++-- > 2 files changed, 153 insertions(+), 11 deletions(-) > > diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig > index b52abc2268cc..5f33358eb2f1 100644 > --- a/drivers/remoteproc/Kconfig > +++ b/drivers/remoteproc/Kconfig > @@ -52,6 +52,18 @@ config OMAP_REMOTEPROC > It's safe to say N here if you're not interested in multimedia > offloading or just want a bare minimum kernel. > > +config OMAP_REMOTEPROC_WATCHDOG > + bool "OMAP remoteproc watchdog timer" > + depends on OMAP_REMOTEPROC > + default n > + help > + Say Y here to enable watchdog timer for remote processors. > + > + This option controls the watchdog functionality for the remote > + processors in OMAP. Dedicated OMAP DMTimers are used by the remote > + processors and triggers the timer interrupt upon a watchdog > + detection. > + > config WKUP_M3_RPROC > tristate "AMx3xx Wakeup M3 remoteproc support" > depends on SOC_AM33XX || SOC_AM43XX > diff --git a/drivers/remoteproc/omap_remoteproc.c b/drivers/remoteproc/omap_remoteproc.c > index ece60a183e19..29d19a608af8 100644 > --- a/drivers/remoteproc/omap_remoteproc.c > +++ b/drivers/remoteproc/omap_remoteproc.c > @@ -24,6 +24,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -72,10 +73,12 @@ struct omap_rproc_mem { > * struct omap_rproc_timer - data structure for a timer used by a omap rproc > * @odt: timer pointer > * @timer_ops: OMAP dmtimer ops for @odt timer > + * @irq: timer irq > */ > struct omap_rproc_timer { > struct omap_dm_timer *odt; > const struct omap_dm_timer_ops *timer_ops; > + int irq; > }; > > /** > @@ -86,6 +89,7 @@ struct omap_rproc_timer { > * @mem: internal memory regions data > * @num_mems: number of internal memory regions > * @num_timers: number of rproc timer(s) > + * @num_wd_timers: number of rproc watchdog timers > * @timers: timer(s) info used by rproc > * @autosuspend_delay: auto-suspend delay value to be used for runtime pm > * @need_resume: if true a resume is needed in the system resume callback > @@ -102,6 +106,7 @@ struct omap_rproc { > struct omap_rproc_mem *mem; > int num_mems; > int num_timers; > + int num_wd_timers; > struct omap_rproc_timer *timers; > int autosuspend_delay; > bool need_resume; > @@ -219,6 +224,79 @@ static inline int omap_rproc_release_timer(struct omap_rproc_timer *timer) > return timer->timer_ops->free(timer->odt); > } > > +/** > + * omap_rproc_get_timer_irq() - get the irq for a timer > + * @timer: handle to a OMAP rproc timer > + * > + * This function is used to get the irq associated with a watchdog timer. The > + * function is called by the OMAP remoteproc driver to register a interrupt > + * handler to handle watchdog events on the remote processor. > + * > + * Return: irq id on success, otherwise a failure as returned by DMTimer ops > + */ > +static inline int omap_rproc_get_timer_irq(struct omap_rproc_timer *timer) > +{ > + return timer->timer_ops->get_irq(timer->odt); > +} > + > +/** > + * omap_rproc_ack_timer_irq() - acknowledge a timer irq > + * @timer: handle to a OMAP rproc timer > + * > + * This function is used to clear the irq associated with a watchdog timer. The > + * The function is called by the OMAP remoteproc upon a watchdog event on the > + * remote processor to clear the interrupt status of the watchdog timer. > + */ > +static inline void omap_rproc_ack_timer_irq(struct omap_rproc_timer *timer) > +{ > + timer->timer_ops->write_status(timer->odt, OMAP_TIMER_INT_OVERFLOW); > +} > + > +/** > + * omap_rproc_watchdog_isr() - Watchdog ISR handler for remoteproc device > + * @irq: IRQ number associated with a watchdog timer > + * @data: IRQ handler data > + * > + * This ISR routine executes the required necessary low-level code to > + * acknowledge a watchdog timer interrupt. There can be multiple watchdog > + * timers associated with a rproc (like IPUs which have 2 watchdog timers, > + * one per Cortex M3/M4 core), so a lookup has to be performed to identify > + * the timer to acknowledge its interrupt. > + * > + * The function also invokes rproc_report_crash to report the watchdog event > + * to the remoteproc driver core, to trigger a recovery. > + * > + * Return: IRQ_HANDLED on success, otherwise IRQ_NONE > + */ > +static irqreturn_t omap_rproc_watchdog_isr(int irq, void *data) > +{ > + struct rproc *rproc = data; > + struct omap_rproc *oproc = rproc->priv; > + struct device *dev = rproc->dev.parent; > + struct omap_rproc_timer *timers = oproc->timers; > + struct omap_rproc_timer *wd_timer = NULL; > + int num_timers = oproc->num_timers + oproc->num_wd_timers; > + int i; > + > + for (i = oproc->num_timers; i < num_timers; i++) { > + if (timers[i].irq > 0 && irq == timers[i].irq) { > + wd_timer = &timers[i]; > + break; > + } > + } > + > + if (!wd_timer) { > + dev_err(dev, "invalid timer\n"); > + return IRQ_NONE; > + } > + > + omap_rproc_ack_timer_irq(wd_timer); > + > + rproc_report_crash(rproc, RPROC_WATCHDOG); > + > + return IRQ_HANDLED; > +} > + > /** > * omap_rproc_enable_timers() - enable the timers for a remoteproc > * @rproc: handle of a remote processor > @@ -242,19 +320,26 @@ static int omap_rproc_enable_timers(struct rproc *rproc, bool configure) > struct omap_rproc_timer *timers = oproc->timers; > struct device *dev = rproc->dev.parent; > struct device_node *np = NULL; > + int num_timers = oproc->num_timers + oproc->num_wd_timers; > > - if (!oproc->num_timers) > + if (!num_timers) > return 0; > > if (!configure) > goto start_timers; > > - for (i = 0; i < oproc->num_timers; i++) { > - np = of_parse_phandle(dev->of_node, "ti,timers", i); > + for (i = 0; i < num_timers; i++) { > + if (i < oproc->num_timers) > + np = of_parse_phandle(dev->of_node, "ti,timers", i); > + else > + np = of_parse_phandle(dev->of_node, > + "ti,watchdog-timers", > + (i - oproc->num_timers)); > if (!np) { > ret = -ENXIO; > dev_err(dev, "device node lookup for timer at index %d failed: %d\n", > - i, ret); > + i < oproc->num_timers ? i : > + i - oproc->num_timers, ret); > goto free_timers; > } > > @@ -277,12 +362,14 @@ static int omap_rproc_enable_timers(struct rproc *rproc, bool configure) > if (!timer_ops || !timer_ops->request_by_node || > !timer_ops->set_source || !timer_ops->set_load || > !timer_ops->free || !timer_ops->start || > - !timer_ops->stop) { > + !timer_ops->stop || !timer_ops->get_irq || > + !timer_ops->write_status) { > ret = -EINVAL; > dev_err(dev, "device does not have required timer ops\n"); > goto put_node; > } > > + timers[i].irq = -1; > timers[i].timer_ops = timer_ops; > ret = omap_rproc_request_timer(dev, np, &timers[i]); > if (ret) { > @@ -291,10 +378,33 @@ static int omap_rproc_enable_timers(struct rproc *rproc, bool configure) > goto put_node; > } > of_node_put(np); > + > + if (i >= oproc->num_timers) { > + timers[i].irq = omap_rproc_get_timer_irq(&timers[i]); > + if (timers[i].irq < 0) { > + dev_err(dev, "get_irq for timer %p failed: %d\n", > + np, timers[i].irq); > + ret = -EBUSY; > + goto free_timers; > + } > + > + ret = request_irq(timers[i].irq, > + omap_rproc_watchdog_isr, IRQF_SHARED, > + "rproc-wdt", rproc); > + if (ret) { > + dev_err(dev, "error requesting irq for timer %p\n", > + np); > + omap_rproc_release_timer(&timers[i]); > + timers[i].odt = NULL; > + timers[i].timer_ops = NULL; > + timers[i].irq = -1; > + goto free_timers; > + } > + } > } > > start_timers: > - for (i = 0; i < oproc->num_timers; i++) { > + for (i = 0; i < num_timers; i++) { > ret = omap_rproc_start_timer(&timers[i]); > if (ret) { > dev_err(dev, "start timer %p failed failed: %d\n", np, > @@ -316,9 +426,12 @@ static int omap_rproc_enable_timers(struct rproc *rproc, bool configure) > of_node_put(np); > free_timers: > while (i--) { > + if (i >= oproc->num_timers) > + free_irq(timers[i].irq, rproc); > omap_rproc_release_timer(&timers[i]); > timers[i].odt = NULL; > timers[i].timer_ops = NULL; > + timers[i].irq = -1; > } > > return ret; > @@ -341,16 +454,20 @@ static int omap_rproc_disable_timers(struct rproc *rproc, bool configure) > int i; > struct omap_rproc *oproc = rproc->priv; > struct omap_rproc_timer *timers = oproc->timers; > + int num_timers = oproc->num_timers + oproc->num_wd_timers; > > - if (!oproc->num_timers) > + if (!num_timers) > return 0; > > - for (i = 0; i < oproc->num_timers; i++) { > + for (i = 0; i < num_timers; i++) { > omap_rproc_stop_timer(&timers[i]); > if (configure) { > + if (i >= oproc->num_timers) > + free_irq(timers[i].irq, rproc); > omap_rproc_release_timer(&timers[i]); > timers[i].odt = NULL; > timers[i].timer_ops = NULL; > + timers[i].irq = -1; > } > } > > @@ -1110,6 +1227,7 @@ static int omap_rproc_of_get_timers(struct platform_device *pdev, > struct device_node *np = pdev->dev.of_node; > struct omap_rproc *oproc = rproc->priv; > struct device *dev = &pdev->dev; > + int num_timers; > > /* > * Timer nodes are directly used in client nodes as phandles, so > @@ -1122,14 +1240,26 @@ static int omap_rproc_of_get_timers(struct platform_device *pdev, > oproc->num_timers = 0; > } > > - if (oproc->num_timers) { > - oproc->timers = devm_kcalloc(dev, oproc->num_timers, > +#ifdef CONFIG_OMAP_REMOTEPROC_WATCHDOG > + oproc->num_wd_timers = > + of_count_phandle_with_args(np, "ti,watchdog-timers", NULL); > + if (oproc->num_wd_timers <= 0) { > + dev_dbg(dev, "device does not have watchdog timers, status = %d\n", > + oproc->num_wd_timers); > + oproc->num_wd_timers = 0; > + } > +#endif I commented on the above in the previous version... > + > + num_timers = oproc->num_timers + oproc->num_wd_timers; > + if (num_timers) { > + oproc->timers = devm_kcalloc(dev, num_timers, > sizeof(*oproc->timers), > GFP_KERNEL); > if (!oproc->timers) > return -ENOMEM; > > - dev_dbg(dev, "device has %d tick timers\n", oproc->num_timers); > + dev_dbg(dev, "device has %d tick timers and %d watchdog timers\n", > + oproc->num_timers, oproc->num_wd_timers); > } > > return 0; > -- > 2.17.1 > > -- > Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. 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