Re: [PATCH v5 2/2] remoteproc: xlnx: add crash detection mechanism

[Mathieu Poirier <mathieu.poirier@linaro.org>]

On Wed, Jun 10, 2026 at 11:27:11AM -0700, Tanmay Shah wrote:
> Remote processor will report the crash reason via the resource table
> and notify the host via mailbox notification. The host checks this
> crash reason on every mailbox notification from the remote and report
> to the rproc core framework. Then the rproc core framework will start
> the recovery process.
> 
> Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
> ---
> 
> changes in v5
>   - use local variable to access crash report pointer
>   - End crash report string with '\0' without relying on fw
> 
>  drivers/remoteproc/xlnx_r5_remoteproc.c | 73 ++++++++++++++++++++++++-
>  1 file changed, 72 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c b/drivers/remoteproc/xlnx_r5_remoteproc.c
> index 3349d1877751..86afff9f3b40 100644
> --- a/drivers/remoteproc/xlnx_r5_remoteproc.c
> +++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
> @@ -112,6 +112,10 @@ struct rsc_tbl_data {
>  	const uintptr_t rsc_tbl;
>  } __packed;
>  
> +enum xlnx_rproc_fw_rsc {
> +	XLNX_RPROC_FW_CRASH_REASON = RSC_VENDOR_START,

I would call this XLNX_RPROC_FW_CRASH_REPORT

> +};
> +
>  /*
>   * Hardcoded TCM bank values. This will stay in driver to maintain backward
>   * compatibility with device-tree that does not have TCM information.
> @@ -131,9 +135,27 @@ static const struct mem_bank_data zynqmp_tcm_banks_lockstep[] = {
>  	{0xffe30000UL, 0x30000, 0x10000UL, PD_R5_1_BTCM, "btcm1"},
>  };
>  
> +#define CRASH_REASON_STR_LEN 16
> +
> +/**
> + * struct xlnx_rproc_crash_report - resource to know crash status and reason
> + *
> + * @version: version of this resource
> + * @crash_state: if true, the rproc is notifying crash, time to recover
> + * @crash_reason: number to describe reason of crash
> + * @crash_reason_str: short string description of crash reason
> + */
> +struct xlnx_rproc_crash_report {
> +	u8 version;
> +	u8 crash_state;
> +	u8 crash_reason;

Do you need 2 variables?  Would it be possible for @crash_reason != 0 to
indicate a crash, making @cash_state irrelevant?

> +	char crash_reason_str[CRASH_REASON_STR_LEN];
> +} __packed;
> +
>  /**
>   * struct zynqmp_r5_core - remoteproc core's internal data
>   *
> + * @crash_report: rproc crash state and reason
>   * @rsc_tbl_va: resource table virtual address
>   * @sram: Array of sram memories assigned to this core
>   * @num_sram: number of sram for this core
> @@ -147,6 +169,7 @@ static const struct mem_bank_data zynqmp_tcm_banks_lockstep[] = {
>   * @ipi: pointer to mailbox information
>   */
>  struct zynqmp_r5_core {
> +	struct xlnx_rproc_crash_report *crash_report;
>  	void __iomem *rsc_tbl_va;
>  	struct zynqmp_sram_bank *sram;
>  	int num_sram;
> @@ -204,11 +227,27 @@ static int event_notified_idr_cb(int id, void *ptr, void *data)
>   */
>  static void handle_event_notified(struct work_struct *work)
>  {
> +	struct xlnx_rproc_crash_report *report;
> +	struct zynqmp_r5_core *r5_core;
>  	struct mbox_info *ipi;
>  	struct rproc *rproc;
>  
>  	ipi = container_of(work, struct mbox_info, mbox_work);
>  	rproc = ipi->r5_core->rproc;
> +	r5_core = ipi->r5_core;
> +	report = r5_core->crash_report;
> +
> +	/* report crash only if expected */
> +	if (report && report->crash_state) {
> +		if (rproc->state == RPROC_ATTACHED || rproc->state == RPROC_RUNNING) {
> +			report->crash_reason_str[CRASH_REASON_STR_LEN - 1] = '\0';
> +			dev_warn(&rproc->dev, "crash reason id: %d %s\n",
> +				 report->crash_reason, report->crash_reason_str);
> +			rproc_report_crash(rproc, RPROC_FATAL_ERROR);
> +			report->crash_state = false;
> +			return;
> +		}
> +	}
>  
>  	/*
>  	 * We only use IPI for interrupt. The RPU firmware side may or may
> @@ -448,6 +487,13 @@ static int zynqmp_r5_rproc_stop(struct rproc *rproc)
>  	if (ret)
>  		dev_err(r5_core->dev, "core force power down failed\n");
>  
> +	/*
> +	 * Clear attach on recovery flag during stop operation. The next state
> +	 * of the remote processor is expected to be "Running" state. In this
> +	 * state boot recovery method must take place over attach on recovery.
> +	 */
> +	test_and_clear_bit(RPROC_FEAT_ATTACH_ON_RECOVERY, rproc->features);

Why is there a need to play set/clear the RPROC_FEAT_ATTACH_ON_RECOVERY flag
here and in zynqmp_r5_attach() and zynqmp_r5_detach()?  I think we talked about
that before but can't remember the outcome of that conversation.

> +
>  	return ret;
>  }
>  
> @@ -869,6 +915,9 @@ static int zynqmp_r5_get_rsc_table_va(struct zynqmp_r5_core *r5_core)
>  
>  static int zynqmp_r5_attach(struct rproc *rproc)
>  {
> +	/* Enable attach on recovery method. Clear it during rproc stop. */
> +	rproc_set_feature(rproc, RPROC_FEAT_ATTACH_ON_RECOVERY);
> +
>  	dev_dbg(&rproc->dev, "rproc %d attached\n", rproc->index);
>  
>  	return 0;
> @@ -883,9 +932,30 @@ static int zynqmp_r5_detach(struct rproc *rproc)
>  	 */
>  	zynqmp_r5_rproc_kick(rproc, 0);
>  
> +	clear_bit(RPROC_FEAT_ATTACH_ON_RECOVERY, rproc->features);
> +
>  	return 0;
>  }
>  
> +static int zynqmp_r5_handle_rsc(struct rproc *rproc, u32 rsc_type, void *rsc,
> +				int offset, int avail)
> +{
> +	struct zynqmp_r5_core *r5_core = rproc->priv;
> +	void *rsc_offset = (r5_core->rsc_tbl_va + offset);
> +

        if (rsc_type != XLNX_RPROC_FW_CRASH_REASON)
                return RSC_IGNORED;

> +	if (rsc_type == XLNX_RPROC_FW_CRASH_REASON) {
> +		r5_core->crash_report = rsc_offset;
> +		/* reset all values */
> +		r5_core->crash_report->crash_state = false;
> +		r5_core->crash_report->crash_reason = 0;
> +		r5_core->crash_report->crash_reason_str[0] = '\0';
> +	} else {
> +		return RSC_IGNORED;
> +	}
> +
> +	return RSC_HANDLED;
> +}
> +
>  static const struct rproc_ops zynqmp_r5_rproc_ops = {
>  	.prepare	= zynqmp_r5_rproc_prepare,
>  	.unprepare	= zynqmp_r5_rproc_unprepare,
> @@ -900,6 +970,7 @@ static const struct rproc_ops zynqmp_r5_rproc_ops = {
>  	.get_loaded_rsc_table = zynqmp_r5_get_loaded_rsc_table,
>  	.attach		= zynqmp_r5_attach,
>  	.detach		= zynqmp_r5_detach,
> +	.handle_rsc	= zynqmp_r5_handle_rsc,
>  };
>  
>  /**
> @@ -939,7 +1010,7 @@ static struct zynqmp_r5_core *zynqmp_r5_alloc_rproc_core(struct device *cdev)
>  
>  	rproc_coredump_set_elf_info(r5_rproc, ELFCLASS32, EM_ARM);
>  
> -	r5_rproc->recovery_disabled = true;
> +	r5_rproc->recovery_disabled = false;

I'm good with the overall architecture of this set.

Regards,
Mathieu

>  	r5_rproc->has_iommu = false;
>  	r5_rproc->auto_boot = false;
>  
> -- 
> 2.34.1
>