Re: [PATCH net,v2] net: mana: Switch to page pool for jumbo frames

On Tue, Mar 25, 2025 at 09:32:37AM -0700, Haiyang Zhang wrote:

Frag allocators, such as netdev_alloc_frag(), were not designed to work for fragsz > PAGE_SIZE.

So, switch to page pool for jumbo frames instead of using page frag allocators. This driver is using page pool for smaller MTUs already.

Cc: stable@vger.kernel.org Fixes: 80f6215b450e ("net: mana: Add support for jumbo frame") Signed-off-by: Haiyang Zhang haiyangz@microsoft.com

---

v2: updated the commit msg as suggested by Jakub Kicinski.

---

drivers/net/ethernet/microsoft/mana/mana_en.c | 46 ++++--------------- 1 file changed, 9 insertions(+), 37 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index 9a8171f099b6..4d41f4cca3d8 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -661,30 +661,16 @@ int mana_pre_alloc_rxbufs(struct mana_port_context *mpc, int new_mtu, int num_qu mpc->rxbpre_total = 0; for (i = 0; i < num_rxb; i++) {

• if (mpc->rxbpre_alloc_size > PAGE_SIZE) {
  

• 	va = netdev_alloc_frag(mpc->rxbpre_alloc_size);
  

• 	if (!va)
  

• 		goto error;
  

• 	page = virt_to_head_page(va);
  

• 	/* Check if the frag falls back to single page */
  

• 	if (compound_order(page) <
  

• 	    get_order(mpc->rxbpre_alloc_size)) {
  

• 		put_page(page);
  

• 		goto error;
  

• 	}
  

• } else {
  

• 	page = dev_alloc_page();
  

• 	if (!page)
  

• 		goto error;
  

• page = dev_alloc_pages(get_order(mpc->rxbpre_alloc_size));
  

• if (!page)
  

• 	goto error;
  

• 	va = page_to_virt(page);
  

• }
  

• va = page_to_virt(page);
  

da = dma_map_single(dev, va + mpc->rxbpre_headroom, mpc->rxbpre_datasize, DMA_FROM_DEVICE); if (dma_mapping_error(dev, da)) {

• 	put_page(virt_to_head_page(va));
  

• 	put_page(page);
  goto error;
  

  }

@@ -1672,7 +1658,7 @@ static void mana_rx_skb(void *buf_va, bool from_pool, } static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev,

• 	     dma_addr_t *da, bool *from_pool, bool is_napi)
  

• 	     dma_addr_t *da, bool *from_pool)
  

{ struct page *page; void *va; @@ -1683,21 +1669,6 @@ static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev, if (rxq->xdp_save_va) { va = rxq->xdp_save_va; rxq->xdp_save_va = NULL;

• } else if (rxq->alloc_size > PAGE_SIZE) {

• if (is_napi)
  

• 	va = napi_alloc_frag(rxq->alloc_size);
  

• else
  

• 	va = netdev_alloc_frag(rxq->alloc_size);
  

• if (!va)
  

• 	return NULL;
  

• page = virt_to_head_page(va);
  

• /* Check if the frag falls back to single page */
  

• if (compound_order(page) < get_order(rxq->alloc_size)) {
  

• 	put_page(page);
  

• 	return NULL;
  

• }
  

  } else { page = page_pool_dev_alloc_pages(rxq->page_pool); if (!page)

@@ -1730,7 +1701,7 @@ static void mana_refill_rx_oob(struct device *dev, struct mana_rxq *rxq, dma_addr_t da; void *va;

• va = mana_get_rxfrag(rxq, dev, &da, &from_pool, true);

• va = mana_get_rxfrag(rxq, dev, &da, &from_pool); if (!va) return;

@@ -2172,7 +2143,7 @@ static int mana_fill_rx_oob(struct mana_recv_buf_oob *rx_oob, u32 mem_key, if (mpc->rxbufs_pre) va = mana_get_rxbuf_pre(rxq, &da); else

• va = mana_get_rxfrag(rxq, dev, &da, &from_pool, false);
  

• va = mana_get_rxfrag(rxq, dev, &da, &from_pool);
  

if (!va) return -ENOMEM; @@ -2258,6 +2229,7 @@ static int mana_create_page_pool(struct mana_rxq *rxq, struct gdma_context *gc) pprm.nid = gc->numa_node; pprm.napi = &rxq->rx_cq.napi; pprm.netdev = rxq->ndev;

• pprm.order = get_order(rxq->alloc_size);

rxq->page_pool = page_pool_create(&pprm); --

Reviewed-by: Shradha Gupta shradhagupta@linux.microsoft.com

2.34.1