Hi,

On 29.01.2017 06:09, Alexander Loktionov wrote:

+
+void aq_ring_tx_append_buffs(struct aq_ring_s *self,
+                            struct aq_ring_buff_s *buffer,
+                            unsigned int buffers)
+{
+       if (likely(self->sw_tail + buffers < self->size)) {
+               memcpy(&self->buff_ring[self->sw_tail], buffer,
+                      sizeof(buffer[0]) * buffers);
+       } else {
+               unsigned int first_part = self->size - self->sw_tail;
+               unsigned int second_part = buffers - first_part;
+
+               memcpy(&self->buff_ring[self->sw_tail], buffer,
+                      sizeof(buffer[0]) * first_part);
+
+               memcpy(&self->buff_ring[0], &buffer[first_part],
+                      sizeof(buffer[0]) * second_part);
+       }
+}

Do you really have to copy each single frame? Copying is an expensive operation that you normally want to avoid on the fast path.


+#define AQ_SKB_ALIGN SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
+int aq_ring_rx_clean(struct aq_ring_s *self, int *work_done, int budget)
+{
+       struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
+       int err = 0;
+       bool is_rsc_completed = true;
+
+       for (; (self->sw_head != self->hw_head) && budget;
+               self->sw_head = aq_ring_next_dx(self, self->sw_head),
+               --budget, ++(*work_done)) {
+               struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
+               struct sk_buff *skb = NULL;
+               unsigned int next_ = 0U;
+               unsigned int i = 0U;
+               struct aq_ring_buff_s *buff_ = NULL;
+
+               if (buff->is_error) {
+                       __free_pages(buff->page, 0);
+                       continue;
+               }
+
+               if (buff->is_cleaned)
+                       continue;
+
+               if (!buff->is_eop) {
+                       for (next_ = buff->next,
+                            buff_ = &self->buff_ring[next_]; true;
+                            next_ = buff_->next,
+                            buff_ = &self->buff_ring[next_]) {
+                               is_rsc_completed =
+                                       aq_ring_dx_in_range(self->sw_head,
+                                                           next_,
+                                                           self->hw_head);
+
+                               if (unlikely(!is_rsc_completed)) {
+                                       is_rsc_completed = false;
+                                       break;
+                               }
+
+                               if (buff_->is_eop)
+                                       break;
+                       }
+
+                       if (!is_rsc_completed) {
+                               err = 0;
+                               goto err_exit;
+                       }
+               }
+
+               /* for single fragment packets use build_skb() */
+               if (buff->is_eop) {
+                       skb = build_skb(page_address(buff->page),
+                                       buff->len + AQ_SKB_ALIGN);
+                       if (unlikely(!skb)) {
+                               err = -ENOMEM;
+                               goto err_exit;
+                       }
+
+                       skb->dev = ndev;

This is already done by eth_type_trans() below (as I already mentioned in a review of a former version of this driver).


+
+void aq_ring_rx_deinit(struct aq_ring_s *self)
+{
+       if (!self)
+               goto err_exit;

Why not return immediately?


+void aq_ring_tx_deinit(struct aq_ring_s *self)
+{
+       if (!self)
+               goto err_exit;

Same here.


+
+void aq_ring_free(struct aq_ring_s *self)
+{
+       if (!self)
+               goto err_exit;

In which case can self be NULL?


index 0000000..0ac3f9e
--- /dev/null
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_ring.h
@@ -0,0 +1,157 @@
+/*
+ * aQuantia Corporation Network Driver
+ * Copyright (C) 2014-2017 aQuantia Corporation. All rights reserved
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+/* File aq_ring.h: Declaration of functions for Rx/Tx rings. */
+
+#ifndef AQ_RING_H
+#define AQ_RING_H
+
+#include "aq_common.h"
+
+struct page;
+
+/*           TxC       SOP        DX         EOP
+ *         +----------+----------+----------+-----------
+ *   8bytes|len l3,l4 | pa       | pa       | pa
+ *         +----------+----------+----------+-----------
+ * 4/8bytes|len pkt   |len pkt   |          | skb
+ *         +----------+----------+----------+-----------
+ * 4/8bytes|is_txc    |len,flags |len       |len,is_eop
+ *         +----------+----------+----------+-----------
+ *
+ *  This aq_ring_buff_s doesn't have endianness dependency.
+ *  It is __packed for cache line optimizations.
+ */
+struct __packed aq_ring_buff_s {

__packed should be avoided if possible. There are macros like
__cacheline_aligned that can be used to ensure cacheline alignment.

Regard,
Lino


Reply via email to