This is a note to let you know that I've just added the patch titled
mlxsw: pci: Sync Rx buffers for CPU
to the 6.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mlxsw-pci-sync-rx-buffers-for-cpu.patch
and it can be found in the queue-6.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e466bae3481a89391145f48aaab761bfc7114f14
Author: Amit Cohen <amcohen@xxxxxxxxxx>
Date: Fri Oct 25 16:26:26 2024 +0200
mlxsw: pci: Sync Rx buffers for CPU
[ Upstream commit 15f73e601a9c67aa83bde92b2d940a6532d8614d ]
When Rx packet is received, drivers should sync the pages for CPU, to
ensure the CPU reads the data written by the device and not stale
data from its cache.
Add the missing sync call in Rx path, sync the actual length of data for
each fragment.
Cc: Jiri Pirko <jiri@xxxxxxxxxxx>
Fixes: b5b60bb491b2 ("mlxsw: pci: Use page pool for Rx buffers allocation")
Signed-off-by: Amit Cohen <amcohen@xxxxxxxxxx>
Reviewed-by: Ido Schimmel <idosch@xxxxxxxxxx>
Signed-off-by: Petr Machata <petrm@xxxxxxxxxx>
Link: https://patch.msgid.link/461486fac91755ca4e04c2068c102250026dcd0b.1729866134.git.petrm@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/mellanox/mlxsw/pci.c b/drivers/net/ethernet/mellanox/mlxsw/pci.c
index 060e5b9392114..2320a5f323b45 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/pci.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/pci.c
@@ -389,15 +389,27 @@ static void mlxsw_pci_wqe_frag_unmap(struct mlxsw_pci *mlxsw_pci, char *wqe,
dma_unmap_single(&pdev->dev, mapaddr, frag_len, direction);
}
-static struct sk_buff *mlxsw_pci_rdq_build_skb(struct page *pages[],
+static struct sk_buff *mlxsw_pci_rdq_build_skb(struct mlxsw_pci_queue *q,
+ struct page *pages[],
u16 byte_count)
{
+ struct mlxsw_pci_queue *cq = q->u.rdq.cq;
unsigned int linear_data_size;
+ struct page_pool *page_pool;
struct sk_buff *skb;
int page_index = 0;
bool linear_only;
void *data;
+ linear_only = byte_count + MLXSW_PCI_RX_BUF_SW_OVERHEAD <= PAGE_SIZE;
+ linear_data_size = linear_only ? byte_count :
+ PAGE_SIZE -
+ MLXSW_PCI_RX_BUF_SW_OVERHEAD;
+
+ page_pool = cq->u.cq.page_pool;
+ page_pool_dma_sync_for_cpu(page_pool, pages[page_index],
+ MLXSW_PCI_SKB_HEADROOM, linear_data_size);
+
data = page_address(pages[page_index]);
net_prefetch(data);
@@ -405,11 +417,6 @@ static struct sk_buff *mlxsw_pci_rdq_build_skb(struct page *pages[],
if (unlikely(!skb))
return ERR_PTR(-ENOMEM);
- linear_only = byte_count + MLXSW_PCI_RX_BUF_SW_OVERHEAD <= PAGE_SIZE;
- linear_data_size = linear_only ? byte_count :
- PAGE_SIZE -
- MLXSW_PCI_RX_BUF_SW_OVERHEAD;
-
skb_reserve(skb, MLXSW_PCI_SKB_HEADROOM);
skb_put(skb, linear_data_size);
@@ -425,6 +432,7 @@ static struct sk_buff *mlxsw_pci_rdq_build_skb(struct page *pages[],
page = pages[page_index];
frag_size = min(byte_count, PAGE_SIZE);
+ page_pool_dma_sync_for_cpu(page_pool, page, 0, frag_size);
skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
page, 0, frag_size, PAGE_SIZE);
byte_count -= frag_size;
@@ -760,7 +768,7 @@ static void mlxsw_pci_cqe_rdq_handle(struct mlxsw_pci *mlxsw_pci,
if (err)
goto out;
- skb = mlxsw_pci_rdq_build_skb(pages, byte_count);
+ skb = mlxsw_pci_rdq_build_skb(q, pages, byte_count);
if (IS_ERR(skb)) {
dev_err_ratelimited(&pdev->dev, "Failed to build skb for RDQ\n");
mlxsw_pci_rdq_pages_recycle(q, pages, num_sg_entries);
