ionic: use dev_consume_skb_any outside of napi

If we're not in a NAPI softirq context, we need to be careful
about how we call napi_consume_skb(), specifically we need to
call it with budget==0 to signal to it that we're not in a
safe context.

This was found while running some configuration stress testing
of traffic and a change queue config loop running, and this
curious note popped out:

[ 4371.402645] BUG: using smp_processor_id() in preemptible [00000000] code: ethtool/20545
[ 4371.402897] caller is napi_skb_cache_put+0x16/0x80
[ 4371.403120] CPU: 25 PID: 20545 Comm: ethtool Kdump: loaded Tainted: G           OE      6.10.0-rc3-netnext+ #8
[ 4371.403302] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 01/23/2021
[ 4371.403460] Call Trace:
[ 4371.403613]  <TASK>
[ 4371.403758]  dump_stack_lvl+0x4f/0x70
[ 4371.403904]  check_preemption_disabled+0xc1/0xe0
[ 4371.404051]  napi_skb_cache_put+0x16/0x80
[ 4371.404199]  ionic_tx_clean+0x18a/0x240 [ionic]
[ 4371.404354]  ionic_tx_cq_service+0xc4/0x200 [ionic]
[ 4371.404505]  ionic_tx_flush+0x15/0x70 [ionic]
[ 4371.404653]  ? ionic_lif_qcq_deinit.isra.23+0x5b/0x70 [ionic]
[ 4371.404805]  ionic_txrx_deinit+0x71/0x190 [ionic]
[ 4371.404956]  ionic_reconfigure_queues+0x5f5/0xff0 [ionic]
[ 4371.405111]  ionic_set_ringparam+0x2e8/0x3e0 [ionic]
[ 4371.405265]  ethnl_set_rings+0x1f1/0x300
[ 4371.405418]  ethnl_default_set_doit+0xbb/0x160
[ 4371.405571]  genl_family_rcv_msg_doit+0xff/0x130
	[...]

I found that ionic_tx_clean() calls napi_consume_skb() which calls
napi_skb_cache_put(), but before that last call is the note
    /* Zero budget indicate non-NAPI context called us, like netpoll */
and
    DEBUG_NET_WARN_ON_ONCE(!in_softirq());

Those are pretty big hints that we're doing it wrong.  We can pass a
context hint down through the calls to let ionic_tx_clean() know what
we're doing so it can call napi_consume_skb() correctly.

Fixes: 386e69865311 ("ionic: Make use napi_consume_skb")
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://patch.msgid.link/20240624175015.4520-1-shannon.nelson@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
index f30eee4a5a80e4bbd15a844da71b06660d4b6b05..b6c01a88098dc58ec533438006373be8a91fa533 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
@@ -375,7 +375,9 @@ typedef void (*ionic_cq_done_cb)(void *done_arg);
 unsigned int ionic_cq_service(struct ionic_cq *cq, unsigned int work_to_do,
                              ionic_cq_cb cb, ionic_cq_done_cb done_cb,
                              void *done_arg);
-unsigned int ionic_tx_cq_service(struct ionic_cq *cq, unsigned int work_to_do);
+unsigned int ionic_tx_cq_service(struct ionic_cq *cq,
+                                unsigned int work_to_do,
+                                bool in_napi);
 
 int ionic_q_init(struct ionic_lif *lif, struct ionic_dev *idev,
                 struct ionic_queue *q, unsigned int index, const char *name,

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.c b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
index 1934e9d6d9e4fb6e45ba976f135daaf77792303f..1837a30ba08ac4dbed38e15d2cecd3c0426d62b4 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_lif.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
@@ -1189,7 +1189,7 @@ static int ionic_adminq_napi(struct napi_struct *napi, int budget)
                                           ionic_rx_service, NULL, NULL);
 
        if (lif->hwstamp_txq)
-               tx_work = ionic_tx_cq_service(&lif->hwstamp_txq->cq, budget);
+               tx_work = ionic_tx_cq_service(&lif->hwstamp_txq->cq, budget, !!budget);
 
        work_done = max(max(n_work, a_work), max(rx_work, tx_work));
        if (work_done < budget && napi_complete_done(napi, work_done)) {

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
index aed7d9cbce038f7d7212c674502722bd9c10db70..9fdd7cd3ef19d43836ffb148eea65fc3404c0c09 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
@@ -23,7 +23,8 @@ static void ionic_tx_desc_unmap_bufs(struct ionic_queue *q,
 
 static void ionic_tx_clean(struct ionic_queue *q,
                           struct ionic_tx_desc_info *desc_info,
-                          struct ionic_txq_comp *comp);
+                          struct ionic_txq_comp *comp,
+                          bool in_napi);
 
 static inline void ionic_txq_post(struct ionic_queue *q, bool ring_dbell)
 {
@@ -944,7 +945,7 @@ int ionic_tx_napi(struct napi_struct *napi, int budget)
        u32 work_done = 0;
        u32 flags = 0;
 
-       work_done = ionic_tx_cq_service(cq, budget);
+       work_done = ionic_tx_cq_service(cq, budget, !!budget);
 
        if (unlikely(!budget))
                return budget;
@@ -1028,7 +1029,7 @@ int ionic_txrx_napi(struct napi_struct *napi, int budget)
        txqcq = lif->txqcqs[qi];
        txcq = &lif->txqcqs[qi]->cq;
 
-       tx_work_done = ionic_tx_cq_service(txcq, IONIC_TX_BUDGET_DEFAULT);
+       tx_work_done = ionic_tx_cq_service(txcq, IONIC_TX_BUDGET_DEFAULT, !!budget);
 
        if (unlikely(!budget))
                return budget;
@@ -1161,7 +1162,8 @@ static void ionic_tx_desc_unmap_bufs(struct ionic_queue *q,
 
 static void ionic_tx_clean(struct ionic_queue *q,
                           struct ionic_tx_desc_info *desc_info,
-                          struct ionic_txq_comp *comp)
+                          struct ionic_txq_comp *comp,
+                          bool in_napi)
 {
        struct ionic_tx_stats *stats = q_to_tx_stats(q);
        struct ionic_qcq *qcq = q_to_qcq(q);
@@ -1213,11 +1215,13 @@ static void ionic_tx_clean(struct ionic_queue *q,
        desc_info->bytes = skb->len;
        stats->clean++;
 
-       napi_consume_skb(skb, 1);
+       napi_consume_skb(skb, likely(in_napi) ? 1 : 0);
 }
 
 static bool ionic_tx_service(struct ionic_cq *cq,
-                            unsigned int *total_pkts, unsigned int *total_bytes)
+                            unsigned int *total_pkts,
+                            unsigned int *total_bytes,
+                            bool in_napi)
 {
        struct ionic_tx_desc_info *desc_info;
        struct ionic_queue *q = cq->bound_q;
@@ -1239,7 +1243,7 @@ static bool ionic_tx_service(struct ionic_cq *cq,
                desc_info->bytes = 0;
                index = q->tail_idx;
                q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
-               ionic_tx_clean(q, desc_info, comp);
+               ionic_tx_clean(q, desc_info, comp, in_napi);
                if (desc_info->skb) {
                        pkts++;
                        bytes += desc_info->bytes;
@@ -1253,7 +1257,9 @@ static bool ionic_tx_service(struct ionic_cq *cq,
        return true;
 }
 
-unsigned int ionic_tx_cq_service(struct ionic_cq *cq, unsigned int work_to_do)
+unsigned int ionic_tx_cq_service(struct ionic_cq *cq,
+                                unsigned int work_to_do,
+                                bool in_napi)
 {
        unsigned int work_done = 0;
        unsigned int bytes = 0;
@@ -1262,7 +1268,7 @@ unsigned int ionic_tx_cq_service(struct ionic_cq *cq, unsigned int work_to_do)
        if (work_to_do == 0)
                return 0;
 
-       while (ionic_tx_service(cq, &pkts, &bytes)) {
+       while (ionic_tx_service(cq, &pkts, &bytes, in_napi)) {
                if (cq->tail_idx == cq->num_descs - 1)
                        cq->done_color = !cq->done_color;
                cq->tail_idx = (cq->tail_idx + 1) & (cq->num_descs - 1);
@@ -1288,7 +1294,7 @@ void ionic_tx_flush(struct ionic_cq *cq)
 {
        u32 work_done;
 
-       work_done = ionic_tx_cq_service(cq, cq->num_descs);
+       work_done = ionic_tx_cq_service(cq, cq->num_descs, false);
        if (work_done)
                ionic_intr_credits(cq->idev->intr_ctrl, cq->bound_intr->index,
                                   work_done, IONIC_INTR_CRED_RESET_COALESCE);
@@ -1305,7 +1311,7 @@ void ionic_tx_empty(struct ionic_queue *q)
                desc_info = &q->tx_info[q->tail_idx];
                desc_info->bytes = 0;
                q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
-               ionic_tx_clean(q, desc_info, NULL);
+               ionic_tx_clean(q, desc_info, NULL, false);
                if (desc_info->skb) {
                        pkts++;
                        bytes += desc_info->bytes;