[PATCH iwl-next v2 2/2] idpf: use GFP_KERNEL for the initial Rx ring fill

[Luigi Rizzo]

When idpf fills its Rx rings at open or on queue reconfiguration, the
allocation runs in process context, right after page_pool_create() and
before the queues' NAPI is enabled. Allocating tens of thousands of
buffers across all queues with GFP_ATOMIC is needlessly restrictive
when the caller may sleep.

In splitq mode, idpf_rx_post_buf_desc() is only used for this initial
fill, so switch its header and payload allocations to
libeth_rx_alloc_gfp(..., GFP_KERNEL).

In singleq mode, add a gfp_t parameter to
idpf_rx_singleq_buf_hw_alloc_all() and pass GFP_KERNEL from
idpf_rx_buf_alloc_singleq() and GFP_ATOMIC from idpf_rx_singleq_clean().

Signed-off-by: Luigi Rizzo <lrizzo@xxxxxxxxxx>
---
 drivers/net/ethernet/intel/idpf/idpf_singleq_txrx.c | 7 ++++---
 drivers/net/ethernet/intel/idpf/idpf_txrx.c         | 9 ++++++---
 drivers/net/ethernet/intel/idpf/idpf_txrx.h         | 2 +-
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_singleq_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_singleq_txrx.c
index e3ddf18dcbf51..d623e4ab8511f 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_singleq_txrx.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_singleq_txrx.c
@@ -885,11 +885,12 @@ static void idpf_rx_buf_hw_update(struct idpf_rx_queue *rxq, u32 val)
  * idpf_rx_singleq_buf_hw_alloc_all - Replace used receive buffers
  * @rx_q: queue for which the hw buffers are allocated
  * @cleaned_count: number of buffers to replace
+ * @gfp: GFP_KERNEL for the initial fill, GFP_ATOMIC from NAPI
  *
  * Returns false if all allocations were successful, true if any fail
  */
 bool idpf_rx_singleq_buf_hw_alloc_all(struct idpf_rx_queue *rx_q,
-				      u16 cleaned_count)
+				      u16 cleaned_count, gfp_t gfp)
 {
 	struct virtchnl2_singleq_rx_buf_desc *desc;
 	const struct libeth_fq_fp fq = {
@@ -908,7 +909,7 @@ bool idpf_rx_singleq_buf_hw_alloc_all(struct idpf_rx_queue *rx_q,
 	do {
 		dma_addr_t addr;
 
-		addr = libeth_rx_alloc(&fq, nta);
+		addr = libeth_rx_alloc_gfp(&fq, nta, gfp);
 		if (addr == DMA_MAPPING_ERROR)
 			break;
 
@@ -1095,7 +1096,7 @@ static int idpf_rx_singleq_clean(struct idpf_rx_queue *rx_q, int budget)
 
 	page_pool_nid_changed(rx_q->pp, numa_mem_id());
 	if (cleaned_count)
-		idpf_rx_singleq_buf_hw_alloc_all(rx_q, cleaned_count);
+		idpf_rx_singleq_buf_hw_alloc_all(rx_q, cleaned_count, GFP_ATOMIC);
 
 	u64_stats_update_begin(&rx_q->stats_sync);
 	u64_stats_add(&rx_q->q_stats.packets, rs.packets);
diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
index 4311ffa30bb18..b1127ab48ef3f 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
@@ -600,6 +600,9 @@ static void idpf_post_buf_refill(struct idpf_sw_queue *refillq, u16 buf_id)
  * @bufq: buffer queue to post to
  * @buf_id: buffer id to post
  *
+ * Only used for the initial fill, from process context, so it allocates
+ * with GFP_KERNEL.
+ *
  * Return: %false if buffer could not be allocated, %true otherwise.
  */
 static bool idpf_rx_post_buf_desc(struct idpf_buf_queue *bufq, u16 buf_id)
@@ -618,7 +621,7 @@ static bool idpf_rx_post_buf_desc(struct idpf_buf_queue *bufq, u16 buf_id)
 		fq.fqes = bufq->hdr_buf;
 		fq.truesize = bufq->hdr_truesize;
 
-		addr = libeth_rx_alloc(&fq, buf_id);
+		addr = libeth_rx_alloc_gfp(&fq, buf_id, GFP_KERNEL);
 		if (addr == DMA_MAPPING_ERROR)
 			return false;
 
@@ -629,7 +632,7 @@ static bool idpf_rx_post_buf_desc(struct idpf_buf_queue *bufq, u16 buf_id)
 	fq.fqes = bufq->buf;
 	fq.truesize = bufq->truesize;
 
-	addr = libeth_rx_alloc(&fq, buf_id);
+	addr = libeth_rx_alloc_gfp(&fq, buf_id, GFP_KERNEL);
 	if (addr == DMA_MAPPING_ERROR)
 		return false;
 
@@ -675,7 +678,7 @@ static bool idpf_rx_post_init_bufs(struct idpf_buf_queue *bufq,
  */
 static int idpf_rx_buf_alloc_singleq(struct idpf_rx_queue *rxq)
 {
-	if (idpf_rx_singleq_buf_hw_alloc_all(rxq, rxq->desc_count - 1))
+	if (idpf_rx_singleq_buf_hw_alloc_all(rxq, rxq->desc_count - 1, GFP_KERNEL))
 		goto err;
 
 	return 0;
diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.h b/drivers/net/ethernet/intel/idpf/idpf_txrx.h
index 93547597efd2a..e27438c78ec79 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_txrx.h
+++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.h
@@ -1123,7 +1123,7 @@ netdev_tx_t idpf_tx_singleq_frame(struct sk_buff *skb,
 				  struct idpf_tx_queue *tx_q);
 netdev_tx_t idpf_tx_start(struct sk_buff *skb, struct net_device *netdev);
 bool idpf_rx_singleq_buf_hw_alloc_all(struct idpf_rx_queue *rxq,
-				      u16 cleaned_count);
+				      u16 cleaned_count, gfp_t gfp);
 bool idpf_rx_process_skb_fields(struct sk_buff *skb,
 				const struct libeth_xdp_buff *xdp,
 				struct libeth_rq_napi_stats *rs);
-- 
2.56.0.212.g129ede20d9-goog