[lvc-project] [PATCH net v5 1/2] octeon_ep: Implement helper for iterating packets in Rx queue
Aleksandr Mishin
amishin at t-argos.ru
Thu Oct 17 13:06:50 MSK 2024
The common code with some packet and index manipulations is extracted and
moved to newly implemented helper to make the code more readable and avoid
duplication. This is a preparation for skb allocation failure handling.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Suggested-by: Simon Horman <horms at kernel.org>
Suggested-by: Paolo Abeni <pabeni at redhat.com>
Signed-off-by: Aleksandr Mishin <amishin at t-argos.ru>
---
Compile tested only.
v5:
- Unmap paged buffer before the skb creation as suggested by Paolo
(https://lore.kernel.org/all/cf656975-69b4-427e-8769-d16575774bba@redhat.com/)
v4: https://lore.kernel.org/all/20241012094950.9438-1-amishin@t-argos.ru/
- Split patch up as suggested by Jakub
(https://lore.kernel.org/all/20241004073311.223efca4@kernel.org/)
v3: https://lore.kernel.org/all/20240930053328.9618-1-amishin@t-argos.ru/
- Implement helper which frees current packet resources and increase
index and descriptor as suggested by Simon
(https://lore.kernel.org/all/20240919134812.GB1571683@kernel.org/)
- v3 has been reviewed-by Simon Horman
(https://lore.kernel.org/all/20240930162622.GF1310185@kernel.org/)
v1: https://lore.kernel.org/all/20240906063907.9591-1-amishin@t-argos.ru/
.../net/ethernet/marvell/octeon_ep/octep_rx.c | 55 +++++++++++--------
1 file changed, 32 insertions(+), 23 deletions(-)
diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
index 4746a6b258f0..a889c1510518 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
@@ -336,6 +336,30 @@ static int octep_oq_check_hw_for_pkts(struct octep_device *oct,
return new_pkts;
}
+/**
+ * octep_oq_next_pkt() - Move to the next packet in Rx queue.
+ *
+ * @oq: Octeon Rx queue data structure.
+ * @buff_info: Current packet buffer info.
+ * @read_idx: Current packet index in the ring.
+ * @desc_used: Current packet descriptor number.
+ *
+ * Free the resources associated with a packet.
+ * Increment packet index in the ring and packet descriptor number.
+ */
+static void octep_oq_next_pkt(struct octep_oq *oq,
+ struct octep_rx_buffer *buff_info,
+ u32 *read_idx, u32 *desc_used)
+{
+ dma_unmap_page(oq->dev, oq->desc_ring[*read_idx].buffer_ptr,
+ PAGE_SIZE, DMA_FROM_DEVICE);
+ buff_info->page = NULL;
+ (*read_idx)++;
+ (*desc_used)++;
+ if (*read_idx == oq->max_count)
+ *read_idx = 0;
+}
+
/**
* __octep_oq_process_rx() - Process hardware Rx queue and push to stack.
*
@@ -367,10 +391,7 @@ static int __octep_oq_process_rx(struct octep_device *oct,
desc_used = 0;
for (pkt = 0; pkt < pkts_to_process; pkt++) {
buff_info = (struct octep_rx_buffer *)&oq->buff_info[read_idx];
- dma_unmap_page(oq->dev, oq->desc_ring[read_idx].buffer_ptr,
- PAGE_SIZE, DMA_FROM_DEVICE);
resp_hw = page_address(buff_info->page);
- buff_info->page = NULL;
/* Swap the length field that is in Big-Endian to CPU */
buff_info->len = be64_to_cpu(resp_hw->length);
@@ -394,36 +415,27 @@ static int __octep_oq_process_rx(struct octep_device *oct,
data_offset = OCTEP_OQ_RESP_HW_SIZE;
rx_ol_flags = 0;
}
+
+ octep_oq_next_pkt(oq, buff_info, &read_idx, &desc_used);
+
+ skb = build_skb((void *)resp_hw, PAGE_SIZE);
+ skb_reserve(skb, data_offset);
+
rx_bytes += buff_info->len;
if (buff_info->len <= oq->max_single_buffer_size) {
- skb = build_skb((void *)resp_hw, PAGE_SIZE);
- skb_reserve(skb, data_offset);
skb_put(skb, buff_info->len);
- read_idx++;
- desc_used++;
- if (read_idx == oq->max_count)
- read_idx = 0;
} else {
struct skb_shared_info *shinfo;
u16 data_len;
- skb = build_skb((void *)resp_hw, PAGE_SIZE);
- skb_reserve(skb, data_offset);
/* Head fragment includes response header(s);
* subsequent fragments contains only data.
*/
skb_put(skb, oq->max_single_buffer_size);
- read_idx++;
- desc_used++;
- if (read_idx == oq->max_count)
- read_idx = 0;
-
shinfo = skb_shinfo(skb);
data_len = buff_info->len - oq->max_single_buffer_size;
while (data_len) {
- dma_unmap_page(oq->dev, oq->desc_ring[read_idx].buffer_ptr,
- PAGE_SIZE, DMA_FROM_DEVICE);
buff_info = (struct octep_rx_buffer *)
&oq->buff_info[read_idx];
if (data_len < oq->buffer_size) {
@@ -438,11 +450,8 @@ static int __octep_oq_process_rx(struct octep_device *oct,
buff_info->page, 0,
buff_info->len,
buff_info->len);
- buff_info->page = NULL;
- read_idx++;
- desc_used++;
- if (read_idx == oq->max_count)
- read_idx = 0;
+
+ octep_oq_next_pkt(oq, buff_info, &read_idx, &desc_used);
}
}
--
2.30.2
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