Re: [PATCH] remoteproc: Add support for predefined notifyids
From: ClÃment Leger
Date: Wed Jan 15 2020 - 10:11:07 EST
----- On 15 Jan, 2020, at 16:09, Arnaud Pouliquen arnaud.pouliquen@xxxxxx wrote:
> On 1/15/20 3:28 PM, ClÃment Leger wrote:
>> Hi Arnaud,
>>
>> ----- On 15 Jan, 2020, at 15:06, Arnaud Pouliquen arnaud.pouliquen@xxxxxx wrote:
>>
>>> Hi ClÃment,
>>>
>>> On 1/15/20 11:21 AM, Clement Leger wrote:
>>>> In order to support preallocated notify ids, if their value is
>>>> equal to FW_RSC_NOTIFY_ID_ANY, then do no allocate a notify id
>>>> dynamically but try to allocate the requested one. This is useful when
>>>> using custom ids to bind them to custom vendor resources. For instance,
>>>> it allow to assign a group of queues to a specific interrupti in order
>>>> to dispatch notifications.
>>>>
>>>> Signed-off-by: Clement Leger <cleger@xxxxxxxxx>
>>>> ---
>>>> drivers/remoteproc/remoteproc_core.c | 27 +++++++++++++++++++--------
>>>> include/linux/remoteproc.h | 1 +
>>>> 2 files changed, 20 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/drivers/remoteproc/remoteproc_core.c
>>>> b/drivers/remoteproc/remoteproc_core.c
>>>> index 307df98347ba..b1485fcd0f11 100644
>>>> --- a/drivers/remoteproc/remoteproc_core.c
>>>> +++ b/drivers/remoteproc/remoteproc_core.c
>>>> @@ -351,14 +351,27 @@ int rproc_alloc_vring(struct rproc_vdev *rvdev, int i)
>>>> /*
>>>> * Assign an rproc-wide unique index for this vring
>>>> * TODO: assign a notifyid for rvdev updates as well
>>>> - * TODO: support predefined notifyids (via resource table)
>>>> */
>>>> - ret = idr_alloc(&rproc->notifyids, rvring, 0, 0, GFP_KERNEL);
>>>> - if (ret < 0) {
>>>> - dev_err(dev, "idr_alloc failed: %d\n", ret);
>>>> - return ret;
>>>> + if (rsc->vring[i].notifyid == FW_RSC_NOTIFY_ID_ANY) {
>>>> + ret = idr_alloc(&rproc->notifyids, rvring, 0, 0, GFP_KERNEL);
>>>> + if (ret < 0) {
>>>> + dev_err(dev, "idr_alloc failed: %d\n", ret);
>>>> + return ret;
>>>> + }
>>>> + notifyid = ret;
>>>> +
>>>> + /* Let the rproc know the notifyid of this vring.*/
>>>> + rsc->vring[i].notifyid = notifyid;
>>>> + } else {
>>>> + /* Reserve requested notify_id */
>>>> + notifyid = rsc->vring[i].notifyid;
>>>> + ret = idr_alloc(&rproc->notifyids, rvring, notifyid,
>>>> + notifyid + 1, GFP_KERNEL);
>>>> + if (ret < 0) {
>>>> + dev_err(dev, "idr_alloc failed: %d\n", ret);
>>>> + return ret;
>>>> + }
>>>> }
>>>> - notifyid = ret;
>>>>
>>>> /* Potentially bump max_notifyid */
>>>> if (notifyid > rproc->max_notifyid)
>>>> @@ -366,8 +379,6 @@ int rproc_alloc_vring(struct rproc_vdev *rvdev, int i)
>>>>
>>>> rvring->notifyid = notifyid;
>>>>
>>>> - /* Let the rproc know the notifyid of this vring.*/
>>>> - rsc->vring[i].notifyid = notifyid;
>>>> return 0;
>>>> }
>>> The rproc_free_vring function resets the notifyid to -1 on free.
>>> This could generate a side effect if the resource table is not reloaded.
>>
>> Oh indeed, I did not thought of that. What would you recommend ?
>> If using -1 in free vring, notify ids will be reallocated at next
>> round.
> Regarding the code i'm not sure that it is useful to reset the notifyID to -1 on
> free.
> In current version, on alloc, the notifyID is overwriten without check.
> And as vdev status is updated, vring struct in resource table should be
> considered as invalid
> Except if i missed a usecase/race condition...
>
>>
>> I was also worried that it would break some existing user applications
>> which uses "0" as a notify id in vring but expect the id to be
>> allocated dynamically. With my modification, it means it will try to
>> use "0" as a predefined id, leading to allocation failure.
>>
> Yes this could introduce regression for firmware that sets 0 as default value.
> Probably better to introduce this patch with a new version of the resource table
> :)
Understood ;)
Regards,
ClÃment
>
> Regards
> Arnaud
>>>
>>>>
>>>> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
>>>> index 16ad66683ad0..dcae3394243e 100644
>>>> --- a/include/linux/remoteproc.h
>>>> +++ b/include/linux/remoteproc.h
>>>> @@ -123,6 +123,7 @@ enum fw_resource_type {
>>>> };
>>>>
>>>> #define FW_RSC_ADDR_ANY (-1)
>>>> +#define FW_RSC_NOTIFY_ID_ANY (-1)This define can also be used in
>>>> rproc_free_vring
>>
>> Indeed.
>>
>> Thanks for your review.
>>
>> Regards,
>>
>> ClÃment
>>
>>>
>>> Regards,
>>> Arnaud
>>>>
>>>> /**
> >>> * struct fw_rsc_carveout - physically contiguous memory request