From: Stephen Boyd <swboyd@chromium.org>
To: Bjorn Andersson <bjorn.andersson@linaro.org>,
Ohad Ben-Cohen <ohad@wizery.com>
Cc: Andy Gross <agross@kernel.org>, Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
linux-arm-msm@vger.kernel.org, linux-remoteproc@vger.kernel.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
Sibi Sankar <sibis@codeaurora.org>,
Rishabh Bhatnagar <rishabhb@codeaurora.org>
Subject: Re: [PATCH v3 6/8] remoteproc: Introduce "panic" callback in ops
Date: Thu, 13 Feb 2020 18:41:08 -0800 [thread overview]
Message-ID: <158164806895.184098.244699295706516537@swboyd.mtv.corp.google.com> (raw)
In-Reply-To: <20200211005059.1377279-7-bjorn.andersson@linaro.org>
Quoting Bjorn Andersson (2020-02-10 16:50:57)
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 097f33e4f1f3..8b6932027d36 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -2216,10 +2218,53 @@ void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type)
> }
> EXPORT_SYMBOL(rproc_report_crash);
>
> +static int rproc_panic_handler(struct notifier_block *nb, unsigned long event,
> + void *ptr)
> +{
> + unsigned int longest = 0;
> + struct rproc *rproc;
> + unsigned int d;
> + int locked;
> +
> + locked = mutex_trylock(&rproc_list_mutex);
> + if (!locked) {
> + pr_err("Failed to acquire rproc list lock, won't call panic functions\n");
> + return NOTIFY_DONE;
> + }
> +
> + list_for_each_entry(rproc, &rproc_list, node) {
> + if (!rproc->ops->panic || rproc->state != RPROC_RUNNING)
> + continue;
> +
> + d = rproc->ops->panic(rproc);
> + if (d > longest)
> + longest = d;
Could be
d = max(longest, d);
> + }
> +
> + mutex_unlock(&rproc_list_mutex);
> +
> + /* Delay panic for the longest requested duration */
> + mdelay(longest);
Is this to flush caches? Maybe indicate that in the comment.
> +
> + return NOTIFY_DONE;
> +}
> +
> +static void __init rproc_init_panic(void)
> +{
> + rproc_panic_nb.notifier_call = rproc_panic_handler;
> + atomic_notifier_chain_register(&panic_notifier_list, &rproc_panic_nb);
This is an atomic notifier, but the notifier function takes a mutex,
which sleeps. It should use spinlocks, and never sleep, given that panic
can be called from anywhere.
> +}
> +
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 16ad66683ad0..14f05f26cbcd 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -369,6 +369,8 @@ enum rsc_handling_status {
> * expects to find it
> * @sanity_check: sanity check the fw image
> * @get_boot_addr: get boot address to entry point specified in firmware
> + * @panic: optional callback to react to system panic, core will delay
> + * panic at least the returned number of milliseconds
> */
> struct rproc_ops {
> int (*start)(struct rproc *rproc);
> @@ -383,6 +385,7 @@ struct rproc_ops {
> int (*load)(struct rproc *rproc, const struct firmware *fw);
> int (*sanity_check)(struct rproc *rproc, const struct firmware *fw);
> u32 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw);
> + unsigned int (*panic)(struct rproc *rproc);
Maybe should be unsigned long to match other "timeouts" in the kernel.
next prev parent reply other threads:[~2020-02-14 2:41 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-11 0:50 [PATCH v3 0/8] remoteproc: qcom: post mortem debug support Bjorn Andersson
2020-02-11 0:50 ` [PATCH v3 1/8] dt-bindings: remoteproc: Add Qualcomm PIL info binding Bjorn Andersson
2020-02-14 2:24 ` Stephen Boyd
2020-02-14 4:58 ` Bjorn Andersson
2020-02-20 17:59 ` Mathieu Poirier
2020-02-11 0:50 ` [PATCH v3 2/8] remoteproc: qcom: Introduce driver to store pil info in IMEM Bjorn Andersson
2020-02-14 2:35 ` Stephen Boyd
2020-02-14 4:57 ` Bjorn Andersson
2020-02-20 19:01 ` Mathieu Poirier
2020-02-11 0:50 ` [PATCH v3 3/8] remoteproc: qcom: Update IMEM PIL info on load Bjorn Andersson
2020-02-20 20:42 ` Mathieu Poirier
2020-02-11 0:50 ` [PATCH v3 4/8] arm64: dts: qcom: qcs404: Add IMEM and PIL info region Bjorn Andersson
2020-02-14 2:37 ` Stephen Boyd
2020-02-14 4:40 ` Bjorn Andersson
2020-02-20 20:47 ` Mathieu Poirier
2020-02-11 0:50 ` [PATCH v3 5/8] arm64: dts: qcom: sdm845: " Bjorn Andersson
2020-02-20 20:48 ` Mathieu Poirier
2020-02-11 0:50 ` [PATCH v3 6/8] remoteproc: Introduce "panic" callback in ops Bjorn Andersson
2020-02-13 16:00 ` Arnaud POULIQUEN
2020-02-14 2:41 ` Stephen Boyd [this message]
2020-02-14 4:37 ` Bjorn Andersson
2020-02-11 0:50 ` [PATCH v3 7/8] remoteproc: qcom: q6v5: Add common panic handler Bjorn Andersson
2020-02-11 0:50 ` [PATCH v3 8/8] remoteproc: qcom: Introduce panic handler for PAS and ADSP Bjorn Andersson
2020-02-14 2:43 ` Stephen Boyd
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