On 2/23/2026 4:40 PM, Shah, Tanmay wrote:
> 
> 
> On 2/23/2026 1:55 PM, Bjorn Andersson wrote:
>> On Mon, Feb 23, 2026 at 10:50:06AM -0800, 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 <[email protected]>
>>> ---
>>>
>>> Changes in v3:
>>>   - %s/kick/mailbox notification/
>>>   - %s/core framework/rproc core framework/
>>>   - fold simple function within zynqmp_r5_handle_rsc().
>>>   - remove spurious change
>>>   - reset crash state after reporting the crash
>>>   - document set and reset of ATTACH_ON_RECOVERY flag
>>>   - set recovery_disabled flag to false
>>>   - check condition rproc->crash_reason != NULL
>>>
>>> Changes in v2:
>>>   - clear attach recovery boot flag during detach and stop ops
>>>
>>>  drivers/remoteproc/xlnx_r5_remoteproc.c | 60 ++++++++++++++++++++++++-
>>>  1 file changed, 59 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c 
>>> b/drivers/remoteproc/xlnx_r5_remoteproc.c
>>> index bd619a6c42aa..0d831330ea90 100644
>>> --- a/drivers/remoteproc/xlnx_r5_remoteproc.c
>>> +++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
>>> @@ -108,6 +108,10 @@ struct rsc_tbl_data {
>>>     const uintptr_t rsc_tbl;
>>>  } __packed;
>>>  
>>> +enum fw_vendor_rsc {
>>> +   FW_RSC_VENDOR_CRASH_REASON = RSC_VENDOR_START,
>>
>> Given that this is a vendor-specific resource, wouldn't it be nice to
>> find e.g. XLNX somewhere in the name? Same thing with the enum itself.
>>
> 
> Ack. I will change name for enum and resource both.
> 
>>> +};
>>> +
>>>  /*
>>>   * Hardcoded TCM bank values. This will stay in driver to maintain backward
>>>   * compatibility with device-tree that does not have TCM information.
>>> @@ -127,9 +131,21 @@ static const struct mem_bank_data 
>>> zynqmp_tcm_banks_lockstep[] = {
>>>     {0xffe30000UL, 0x30000, 0x10000UL, PD_R5_1_BTCM, "btcm1"},
>>>  };
>>>  
>>> +/**
>>> + * struct xlnx_rproc_crash_report - resource to know crash status and 
>>> reason
>>> + *
>>> + * @crash_state: if true, the rproc is notifying crash, time to recover
>>> + * @crash_reason: reason of crash
>>> + */
>>> +struct xlnx_rproc_crash_report {
>>> +   u32 crash_state;
>>> +   u32 crash_reason;
>>> +} __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
>>> @@ -143,6 +159,7 @@ 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;
>>> @@ -227,10 +244,14 @@ static void handle_event_notified(struct work_struct 
>>> *work)
>>>  static void zynqmp_r5_mb_rx_cb(struct mbox_client *cl, void *msg)
>>>  {
>>>     struct zynqmp_ipi_message *ipi_msg, *buf_msg;
>>> +   struct zynqmp_r5_core *r5_core;
>>> +   struct rproc *rproc;
>>>     struct mbox_info *ipi;
>>>     size_t len;
>>>  
>>>     ipi = container_of(cl, struct mbox_info, mbox_cl);
>>> +   r5_core = ipi->r5_core;
>>> +   rproc = r5_core->rproc;
>>>  
>>>     /* copy data from ipi buffer to r5_core */
>>>     ipi_msg = (struct zynqmp_ipi_message *)msg;
>>> @@ -244,6 +265,16 @@ static void zynqmp_r5_mb_rx_cb(struct mbox_client *cl, 
>>> void *msg)
>>>     buf_msg->len = len;
>>>     memcpy(buf_msg->data, ipi_msg->data, len);
>>>  
>>> +   /* Check for crash only if rproc crash is expected */
>>> +   if (rproc->state == RPROC_ATTACHED || rproc->state == RPROC_RUNNING) {
>>> +           if (r5_core->crash_report && 
>>> r5_core->crash_report->crash_state) {
>>
>> Nit. I'd prefer the order of these to be swapped...
>>
>> Compare:
>>
>> "Check if we have crashed, and if so check that we're in a state where
>> that makes sense."
>>
>> vs the way you're ordering this:
>>
>> "Check if we're in a state, and if in that state we have crashed"
>>
>>
>> The "have we crashed" question is the most-significant-bit of this
>> chunk, making that the outermost conditional makes it faster for the
>> next reader to orient themselves in the code.
> 
> Ack, that makes sense.
> 
>>
>>> +                   rproc_report_crash(rproc,
>>> +                                      r5_core->crash_report->crash_reason);
>>
>> Are these two value spaces synchronized? crash_reason seems to be a
>> generic 32-bit number without particular definition, and you pass it
>> into a enum rproc_crash_type.
>>
> 
> Yes, crash_reason is supposed to be enum rproc_crash_type.
> 
>> I presume the outcome is that you get the string
>> "crash detected in <name>: type: unknown" in your log for most cases?
>>
> 
> So far, we have only "WATCHDOG" and "FATAL ERROR" cases. I guess any
> more reasons would have to go in the "unknown" case.
> 
>>
>> In the Qualcomm drivers we can get RPROC_WATCHDOG or RPROC_FATAL_ERROR.
>> For the watchdog bite there isn't much information, but for the fatal
>> error we have a error string which we print, then we call
>> rproc_report_crash(FATAL) which results in another "useless" print.
>>
>> Perhaps we could expand rproc_report_crash() to allow drivers to provide
>> some information about the crash beyond the enum.
>>
>> Something like:
>>      rproc_report_crash(rproc, RPROC_FATAL_ERROR, "%d", 
>> report->crash_reason);
>>
>> Would that be useful to you? Would it be valuable to turn your
>> "crash_reason" into a human readable string?
>>
> 
> Yes, it is valuable to turn "crash_reason" to human readable string.
> Should we leave that part to each driver and not have it in the common
> framework?
> 
> If we are to refactor rproc_report_crash, then I think following is more
> flexible:
> 
> rproc_report_crash(rproc, const char *crash_reason_str);
> 
> Then each platform driver can print crash reason however they see fit.
> We can also avoid printing crash reason two times this way.
> 

Hi Bjorn,

I take this back. I think crash_reason can be defined differently for
each firmware project. I would like to provide that flexibility to the
firmware developer. Hence, I prefer not to convert crash_reason integer
to human readable string, as can be different for different fw projects.

Instead, the xlnx platform driver will simply print the crash_reason
integer as given by the firmware, and notify the crash to the core
framework as following:

rproc_report_crash(rproc, RPROC_FATAL_ERROR);

This way, we don't have to modify the rproc_report_crash() API.
I hope this makes sense.

I will wait for your response before sending the new version. Rest of
the comments I will address as asked.

Thanks,
Tanmay

> If we do this, then crash_reason can be defined for each driver
> individually. That's more appropriate as each vendor can have different
> enum for crash.
> 
> Let me know your thoughts.
> 
>>> +                   r5_core->crash_report->crash_state = 0;
>>> +                   r5_core->crash_report->crash_reason = 0;
>>> +           }
>>> +   }
>>> +
>>>     /* received and processed interrupt ack */
>>>     if (mbox_send_message(ipi->rx_chan, NULL) < 0)
>>>             dev_err(cl->dev, "ack failed to mbox rx_chan\n");
>>> @@ -438,6 +469,13 @@ 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);
>>> +
>>>     return ret;
>>>  }
>>>  
>>> @@ -859,6 +897,9 @@ 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;
>>> @@ -873,9 +914,25 @@ 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 == FW_RSC_VENDOR_CRASH_REASON)
>>> +           r5_core->crash_report = (struct xlnx_rproc_crash_report 
>>> *)(rsc_offset);
>>
>> I don't think you need the cast.
>>
>> Regards,
>> Bjorn
>>
>>> +   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,
>>> @@ -890,6 +947,7 @@ 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,
>>>  };
>>>  
>>>  /**
>>> @@ -923,7 +981,7 @@ static struct zynqmp_r5_core 
>>> *zynqmp_r5_add_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;
>>>     r5_rproc->has_iommu = false;
>>>     r5_rproc->auto_boot = false;
>>>     r5_core = r5_rproc->priv;
>>> -- 
>>> 2.34.1
>>>
> 


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