Re: [PATCH v1 09/12] net/ice/base: improve global config lock behavior

[Jacob Keller <jacob.e.keller@intel.com>]

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On 9/5/2025 8:32 AM, Bruce Richardson wrote:
> On Tue, Sep 02, 2025 at 06:26:59PM +0100, Anatoly Burakov wrote:
>> From: Jacob Keller <jacob.e.keller@intel.com>
>>
>> The ice_cfg_tx_topo function attempts to apply Tx scheduler topology
>> configuration based on NVM parameters, selecting either a 5 or 9 layer
>> topology.
>>
>> As part of this flow, the driver acquires the "Global Configuration
>> Lock", which is a hardware resource associated with programming the DDP
>> package to the device. This "lock" is implemented by firmware as a way to
>> guarantee that only one PF can program the DDP for a device. Unlike a
>> traditional lock, once a PF has acquired this lock, no other PF will be
>> able to acquire it again (including that PF) until a core reset of the
>> device. Future requests to acquire the lock report that global
>> configuration has already completed.
>>
>> The following flow is used to program the Tx topology:
>>
>>  * Read the DDP package for scheduler configuration data
>>  * Acquire the global configuration lock
>>  * Program Tx scheduler topology according to DDP package data
>>  * Trigger a core reset which clears the global configuration lock
>>
>> This is followed by the flow for programming the DDP package:
>>
>>  * Acquire the global configuration lock (again)
>>  * Download the DDP package to the device
>>  * Release the global configuration lock.
>>
>> However, if configuration of the Tx topology fails, (i.e.
>> ice_get_set_tx_topo() returns an error code), the driver exits
>> ice_cfg_tx_topo() immediately, and fails to trigger core reset.
>>
>> While the global configuration lock is held, the firmware rejects most
>> AdminQ commands, as it is waiting for the DDP package download (or Tx
>> scheduler topology programming) to occur.
>>
>> The current driver flows assume that the global configuration lock has
>> been reset after programming the Tx topology. Thus, the same PF attempts
>> to acquire the global lock again, and fails. This results in the driver
>> reporting "an unknown error occurred when loading the DDP package". It
>> then attempts to enter safe mode, but ultimately fails to finish
>> ice_probe() since nearly all AdminQ command report error codes, and the
>> driver stops loading the device at some point during its initialization.
>>
>> We cannot simply release the global lock after a failed call to
>> ice_get_set_tx_topo(). Releasing the lock indicates to firmware that
>> global configuration (downloading of the DDP) has completed. Future
>> attempts by this or other PFs to load the DDP will fail with a report
>> that the DDP package has already been downloaded. Then, PFs will enter
>> safe mode as they realize that the package on the device does not meet
>> the minimum version requirement to load. The reported error messages are
>> confusing, as they indicate the version of the default "safe mode"
>> package in the NVM, rather than the version of the DDP package loaded
>> from the filesystem.
>>
>> Instead, we need to trigger core reset to clear global configuration.
>> This is the lowest level of hardware reset which clears the global
>> configuration lock and related state. It also clears any already
>> downloaded DDP. Crucially, it does *not* clear the Tx scheduler topology
>> configuration.
>>
>> Refactor ice_cfg_tx_topo() to always trigger a core reset after acquiring
>> the global lock, regardless of success or failure of the topology
>> configuration.
>>
>> We need to re-initialize the HW structure when we trigger the core reset.
>> Previously, this was the responsibility of the core driver to cleanup
>> after the core reset. Instead, make it the responsibility of this
>> function. This avoids needless re-initialization for the cases where no
>> reset occurred.
>>
>> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
>> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
>> ---
>>  drivers/net/intel/ice/base/ice_ddp.c | 34 ++++++++++++++++++----------
>>  1 file changed, 22 insertions(+), 12 deletions(-)
>>
> 
> Acked-by: Bruce Richardson <bruce.richardson@intel.com>
> 
> See one comment inline below.
> 
> 
>> diff --git a/drivers/net/intel/ice/base/ice_ddp.c b/drivers/net/intel/ice/base/ice_ddp.c
>> index 850c722a3f..68e75be4d2 100644
>> --- a/drivers/net/intel/ice/base/ice_ddp.c
>> +++ b/drivers/net/intel/ice/base/ice_ddp.c
>> @@ -2370,7 +2370,7 @@ int ice_cfg_tx_topo(struct ice_hw *hw, u8 *buf, u32 len)
>>  	struct ice_buf_hdr *section;
>>  	struct ice_pkg_hdr *pkg_hdr;
>>  	enum ice_ddp_state state;
>> -	u16 i, size = 0, offset;
>> +	u16 size = 0, offset;
>>  	u32 reg = 0;
>>  	int status;
>>  	u8 flags;
>> @@ -2457,25 +2457,35 @@ int ice_cfg_tx_topo(struct ice_hw *hw, u8 *buf, u32 len)
>>  	/* check reset was triggered already or not */
>>  	reg = rd32(hw, GLGEN_RSTAT);
>>  	if (reg & GLGEN_RSTAT_DEVSTATE_M) {
>> -		/* Reset is in progress, re-init the hw again */
>>  		ice_debug(hw, ICE_DBG_INIT, "Reset is in progress. layer topology might be applied already\n");
>>  		ice_check_reset(hw);
>> -		return 0;
>> +		/* Reset is in progress, re-init the hw again */
>> +		goto reinit_hw;
>>  	}
>>  
>>  	/* set new topology */
>>  	status = ice_get_set_tx_topo(hw, new_topo, size, NULL, NULL, true);
>>  	if (status) {
>> -		ice_debug(hw, ICE_DBG_INIT, "Set tx topology is failed\n");
>> -		return status;
>> +		ice_debug(hw, ICE_DBG_INIT, "Failed setting Tx topology, status %d\n",
>> +			  status);
>> +		status = ICE_ERR_CFG;
>>  	}
>>  
>> -	/* new topology is updated, delay 1 second before issuing the CORRER */
>> -	for (i = 0; i < 10; i++)
>> -		ice_msec_delay(100, true);
>> +	/* Even if Tx topology config failed, we need to CORE reset here to
>> +	 * clear the global configuration lock. Delay 1 second to allow
>> +	 * hardware to settle then issue a CORER
>> +	 */
>> +	ice_msec_delay(1000, true);
>>  	ice_reset(hw, ICE_RESET_CORER);
>> -	/* CORER will clear the global lock, so no explicit call
>> -	 * required for release
>> -	 */
>> -	return 0;
>> +	ice_check_reset(hw);
>> +
>> +reinit_hw:
>> +	/* Since we triggered a CORER, re-initialize hardware */
>> +	ice_deinit_hw(hw);
>> +	if (ice_init_hw(hw)) {
>> +		ice_debug(hw, ICE_DBG_INIT, "Failed to re-init hardware after setting Tx topology\n");
>> +		return ICE_ERR_RESET_FAILED;
>> +	}
>> +
>> +	return status;
>>  }
> 
> There is a similer deinit + init combo in ice_init_pkg in the same file,
> which is the only use of this function (in DPDK anyway). Therefore, I
> believe that that code can be removed now that the reinit is handled by the
> cfg_tx_topo() function.

I am not sure we can do that. We program Tx topology by taking the
global configuration lock, then programming the topology, and then
performing a CORE reset. We can't simply release the global config lock,
because then DDP won't be able to download at all. We can't avoid this
re-init, because after a CORE reset, the drivers AQ setup will be hosed
and thus we need a re-init.

ice_init_pkg should be called after Tx topology is executed. If another
reset occurs there, I think you may still need to do that re-init too.
There could possibly be a complete refactor that removed the need for a
double reset, but I am not certain.

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