Re: [PATCH] remoteproc: Add support for predefined notifyids

From: ClÃment Leger
Date: Wed Jan 15 2020 - 09:28:33 EST


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.

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.

>
>>
>> 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