Re: [PATCH net] octeontx2-pf: Fix lmtst Id used in aura free

[Pavan Chebbi]

On Fri, Dec 23, 2022 at 6:27 AM Geetha sowjanya <gakula@xxxxxxxxxxx> wrote:
>
> Current code uses per_cpu pointer to get the lmtst_id mapped to
> the core on which aura_free() is executed. Using per_cpu pointer
> without preemption disable causing mismatch between lmtst_id and
> core on which pointer gets freed. This patch fixes the issue by
> disabling preemption around aura_free.
>
> This patch also addresses the memory reservation issue,
> currently NIX, NPA queue context memory is being allocated using
> GFP_KERNEL flag which inturns allocates from memory reserved for
> CMA_DMA. Sizing CMA_DMA memory is getting difficult due to this
> dependency, the more number of interfaces enabled the more the
> CMA_DMA memory requirement.
>
> To fix this issue, GFP_KERNEL flag is replaced with GFP_ATOMIC,
> with this memory will be allocated from unreserved memory.
>
> Fixes: ef6c8da71eaf ("octeontx2-pf: cn10K: Reserve LMTST lines per core")

Two separate issues are being fixed. I think these two fixes should be
separate patches.

> Signed-off-by: Sunil Goutham <sgoutham@xxxxxxxxxxx>
> Signed-off-by: Geetha sowjanya <gakula@xxxxxxxxxxx>
> ---
>  .../ethernet/marvell/octeontx2/af/common.h    |  2 +-
>  .../marvell/octeontx2/nic/otx2_common.c       | 30 +++++++++++++------
>  2 files changed, 22 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/common.h b/drivers/net/ethernet/marvell/octeontx2/af/common.h
> index 8931864ee110..4b4be9ca4d2f 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/af/common.h
> +++ b/drivers/net/ethernet/marvell/octeontx2/af/common.h
> @@ -61,7 +61,7 @@ static inline int qmem_alloc(struct device *dev, struct qmem **q,
>         qmem->entry_sz = entry_sz;
>         qmem->alloc_sz = (qsize * entry_sz) + OTX2_ALIGN;
>         qmem->base = dma_alloc_attrs(dev, qmem->alloc_sz, &qmem->iova,
> -                                    GFP_KERNEL, DMA_ATTR_FORCE_CONTIGUOUS);
> +                                    GFP_ATOMIC, DMA_ATTR_FORCE_CONTIGUOUS);
>         if (!qmem->base)
>                 return -ENOMEM;
>
> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
> index 9e10e7471b88..88f8772a61cd 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
> @@ -1012,6 +1012,7 @@ static void otx2_pool_refill_task(struct work_struct *work)
>         rbpool = cq->rbpool;
>         free_ptrs = cq->pool_ptrs;
>
> +       get_cpu();
>         while (cq->pool_ptrs) {
>                 if (otx2_alloc_rbuf(pfvf, rbpool, &bufptr)) {
>                         /* Schedule a WQ if we fails to free atleast half of the
> @@ -1031,6 +1032,7 @@ static void otx2_pool_refill_task(struct work_struct *work)
>                 pfvf->hw_ops->aura_freeptr(pfvf, qidx, bufptr + OTX2_HEAD_ROOM);
>                 cq->pool_ptrs--;
>         }
> +       put_cpu();
>         cq->refill_task_sched = false;
>  }
>
> @@ -1368,6 +1370,7 @@ int otx2_sq_aura_pool_init(struct otx2_nic *pfvf)
>         if (err)
>                 goto fail;
>
> +       get_cpu();
>         /* Allocate pointers and free them to aura/pool */
>         for (qidx = 0; qidx < hw->tot_tx_queues; qidx++) {
>                 pool_id = otx2_get_pool_idx(pfvf, AURA_NIX_SQ, qidx);
> @@ -1376,18 +1379,24 @@ int otx2_sq_aura_pool_init(struct otx2_nic *pfvf)
>                 sq = &qset->sq[qidx];
>                 sq->sqb_count = 0;
>                 sq->sqb_ptrs = kcalloc(num_sqbs, sizeof(*sq->sqb_ptrs), GFP_KERNEL);
> -               if (!sq->sqb_ptrs)
> -                       return -ENOMEM;
> +               if (!sq->sqb_ptrs) {
> +                       err = -ENOMEM;
> +                       goto err_mem;
> +               }
>
>                 for (ptr = 0; ptr < num_sqbs; ptr++) {
> -                       if (otx2_alloc_rbuf(pfvf, pool, &bufptr))
> -                               return -ENOMEM;
> +                       err = otx2_alloc_rbuf(pfvf, pool, &bufptr);
> +                       if (err)
> +                               goto err_mem;
>                         pfvf->hw_ops->aura_freeptr(pfvf, pool_id, bufptr);
>                         sq->sqb_ptrs[sq->sqb_count++] = (u64)bufptr;
>                 }
>         }
>
> -       return 0;
> +err_mem:
> +       put_cpu();
> +       return err ? -ENOMEM : 0;
> +
>  fail:
>         otx2_mbox_reset(&pfvf->mbox.mbox, 0);
>         otx2_aura_pool_free(pfvf);
> @@ -1426,18 +1435,21 @@ int otx2_rq_aura_pool_init(struct otx2_nic *pfvf)
>         if (err)
>                 goto fail;
>
> +       get_cpu();
>         /* Allocate pointers and free them to aura/pool */
>         for (pool_id = 0; pool_id < hw->rqpool_cnt; pool_id++) {
>                 pool = &pfvf->qset.pool[pool_id];
>                 for (ptr = 0; ptr < num_ptrs; ptr++) {
> -                       if (otx2_alloc_rbuf(pfvf, pool, &bufptr))
> -                               return -ENOMEM;
> +                       err = otx2_alloc_rbuf(pfvf, pool, &bufptr);
> +                       if (err)
> +                               goto err_mem;
>                         pfvf->hw_ops->aura_freeptr(pfvf, pool_id,
>                                                    bufptr + OTX2_HEAD_ROOM);
>                 }
>         }
> -
> -       return 0;
> +err_mem:
> +       put_cpu();
> +       return err ? -ENOMEM : 0;
>  fail:
>         otx2_mbox_reset(&pfvf->mbox.mbox, 0);
>         otx2_aura_pool_free(pfvf);
> --
> 2.25.1
>

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