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From:   Chen Lin <chen45464546@163.com>
To:     nbd@nbd.name, kuba@kernel.org
Cc:     john@phrozen.org, sean.wang@mediatek.com, Mark-MC.Lee@mediatek.com,
        davem@davemloft.net, edumazet@google.com, pabeni@redhat.com,
        matthias.bgg@gmail.com, netdev@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
        alexander.duyck@gmail.com, Chen Lin <chen45464546@163.com>
Subject: [PATCH v2] net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface netdev[napi]_alloc_frag
Date:   Fri,  3 Jun 2022 16:46:08 +0800
Message-Id: <1654245968-8067-1-git-send-email-chen45464546@163.com>
In-Reply-To: <2997c5b0-3611-5e00-466c-b2966f09f067@nbd.name>
References: <2997c5b0-3611-5e00-466c-b2966f09f067@nbd.name>
Precedence: bulk

When rx_flag == MTK_RX_FLAGS_HWLRO, 
rx_data_len = MTK_MAX_LRO_RX_LENGTH(4096 * 3) > PAGE_SIZE.
netdev_alloc_frag is for alloction of page fragment only.
Reference to other drivers and Documentation/vm/page_frags.rst

Branch to use alloc_pages when ring->frag_size > PAGE_SIZE.

Signed-off-by: Chen Lin <chen45464546@163.com>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |   22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index b3b3c07..772d903 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1467,7 +1467,16 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
 			goto release_desc;
 
 		/* alloc new buffer */
-		new_data = napi_alloc_frag(ring->frag_size);
+		if (ring->frag_size <= PAGE_SIZE) {
+			new_data = napi_alloc_frag(ring->frag_size);
+		} else {
+			struct page *page;
+			unsigned int order = get_order(ring->frag_size);
+
+			page = alloc_pages(GFP_ATOMIC | __GFP_COMP |
+					    __GFP_NOWARN, order);
+			new_data = page ? page_address(page) : NULL;
+		}
 		if (unlikely(!new_data)) {
 			netdev->stats.rx_dropped++;
 			goto release_desc;
@@ -1914,7 +1923,16 @@ static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag)
 		return -ENOMEM;
 
 	for (i = 0; i < rx_dma_size; i++) {
-		ring->data[i] = netdev_alloc_frag(ring->frag_size);
+		if (ring->frag_size <= PAGE_SIZE) {
+			ring->data[i] = netdev_alloc_frag(ring->frag_size);
+		} else {
+			struct page *page;
+			unsigned int order = get_order(ring->frag_size);
+
+			page = alloc_pages(GFP_KERNEL | __GFP_COMP |
+					    __GFP_NOWARN, order);
+			ring->data[i] = page ? page_address(page) : NULL;
+		}
 		if (!ring->data[i])
 			return -ENOMEM;
 	}
-- 
1.7.9.5