[v2 PATCH net] octeontx2-pf: Fix lmtst ID used in aura free

[v2 PATCH net] octeontx2-pf: Fix lmtst ID used in aura free

[Geetha sowjanya]

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.

Fixes: ef6c8da71eaf ("octeontx2-pf: cn10K: Reserve LMTST lines per core")
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: Geetha sowjanya <gakula@marvell.com>
---
v1-v2:
- Moved the RVU AF driver fix to different patch.

 .../marvell/octeontx2/nic/otx2_common.c       | 30 +++++++++++++------
 1 file changed, 21 insertions(+), 9 deletions(-)

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

Re: [v2 PATCH net] octeontx2-pf: Fix lmtst ID used in aura free

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:

On Tue, 3 Jan 2023 09:20:12 +0530 you 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.
> 
> Fixes: ef6c8da71eaf ("octeontx2-pf: cn10K: Reserve LMTST lines per core")
> Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
> Signed-off-by: Geetha sowjanya <gakula@marvell.com>
> 
> [...]

Here is the summary with links:
  - [v2,net] octeontx2-pf: Fix lmtst ID used in aura free
    https://git.kernel.org/netdev/net/c/4af1b64f80fb

You are awesome, thank you!
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