From 47922fcde5365a2d37e8d4056e537fc8a7213c39 Mon Sep 17 00:00:00 2001 From: Hayes Wang Date: Tue, 13 Aug 2019 11:42:08 +0800 Subject: r8152: support skb_add_rx_frag Use skb_add_rx_frag() to reduce the memory copy for rx data. Use a new list of rx_used to store the rx buffer which couldn't be reused yet. Besides, the total number of rx buffer may be increased or decreased dynamically. And it is limited by RTL8152_MAX_RX_AGG. Signed-off-by: Hayes Wang Signed-off-by: Jakub Kicinski --- drivers/net/usb/r8152.c | 120 ++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 105 insertions(+), 15 deletions(-) diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index f41cb728e999..2ae04522cd5a 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -584,6 +584,9 @@ enum rtl_register_content { #define TX_ALIGN 4 #define RX_ALIGN 8 +#define RTL8152_MAX_RX_AGG (10 * RTL8152_MAX_RX) +#define RTL8152_RXFG_HEADSZ 256 + #define INTR_LINK 0x0004 #define RTL8152_REQT_READ 0xc0 @@ -720,7 +723,7 @@ struct r8152 { struct net_device *netdev; struct urb *intr_urb; struct tx_agg tx_info[RTL8152_MAX_TX]; - struct list_head rx_info; + struct list_head rx_info, rx_used; struct list_head rx_done, tx_free; struct sk_buff_head tx_queue, rx_queue; spinlock_t rx_lock, tx_lock; @@ -1476,7 +1479,7 @@ static void free_rx_agg(struct r8152 *tp, struct rx_agg *agg) list_del(&agg->info_list); usb_free_urb(agg->urb); - __free_pages(agg->page, get_order(tp->rx_buf_sz)); + put_page(agg->page); kfree(agg); atomic_dec(&tp->rx_count); @@ -1494,7 +1497,7 @@ static struct rx_agg *alloc_rx_agg(struct r8152 *tp, gfp_t mflags) if (!rx_agg) return NULL; - rx_agg->page = alloc_pages(mflags, order); + rx_agg->page = alloc_pages(mflags | __GFP_COMP, order); if (!rx_agg->page) goto free_rx; @@ -1947,6 +1950,46 @@ return_result: return checksum; } +static inline bool rx_count_exceed(struct r8152 *tp) +{ + return atomic_read(&tp->rx_count) > RTL8152_MAX_RX; +} + +static inline int agg_offset(struct rx_agg *agg, void *addr) +{ + return (int)(addr - agg->buffer); +} + +static struct rx_agg *rtl_get_free_rx(struct r8152 *tp, gfp_t mflags) +{ + struct rx_agg *agg, *agg_next, *agg_free = NULL; + unsigned long flags; + + spin_lock_irqsave(&tp->rx_lock, flags); + + list_for_each_entry_safe(agg, agg_next, &tp->rx_used, list) { + if (page_count(agg->page) == 1) { + if (!agg_free) { + list_del_init(&agg->list); + agg_free = agg; + continue; + } + if (rx_count_exceed(tp)) { + list_del_init(&agg->list); + free_rx_agg(tp, agg); + } + break; + } + } + + spin_unlock_irqrestore(&tp->rx_lock, flags); + + if (!agg_free && atomic_read(&tp->rx_count) < RTL8152_MAX_RX_AGG) + agg_free = alloc_rx_agg(tp, mflags); + + return agg_free; +} + static int rx_bottom(struct r8152 *tp, int budget) { unsigned long flags; @@ -1982,7 +2025,7 @@ static int rx_bottom(struct r8152 *tp, int budget) list_for_each_safe(cursor, next, &rx_queue) { struct rx_desc *rx_desc; - struct rx_agg *agg; + struct rx_agg *agg, *agg_free; int len_used = 0; struct urb *urb; u8 *rx_data; @@ -1994,6 +2037,8 @@ static int rx_bottom(struct r8152 *tp, int budget) if (urb->actual_length < ETH_ZLEN) goto submit; + agg_free = rtl_get_free_rx(tp, GFP_ATOMIC); + rx_desc = agg->buffer; rx_data = agg->buffer; len_used += sizeof(struct rx_desc); @@ -2001,7 +2046,7 @@ static int rx_bottom(struct r8152 *tp, int budget) while (urb->actual_length > len_used) { struct net_device *netdev = tp->netdev; struct net_device_stats *stats = &netdev->stats; - unsigned int pkt_len; + unsigned int pkt_len, rx_frag_head_sz; struct sk_buff *skb; /* limite the skb numbers for rx_queue */ @@ -2019,22 +2064,37 @@ static int rx_bottom(struct r8152 *tp, int budget) pkt_len -= ETH_FCS_LEN; rx_data += sizeof(struct rx_desc); - skb = napi_alloc_skb(napi, pkt_len); + if (!agg_free || RTL8152_RXFG_HEADSZ > pkt_len) + rx_frag_head_sz = pkt_len; + else + rx_frag_head_sz = RTL8152_RXFG_HEADSZ; + + skb = napi_alloc_skb(napi, rx_frag_head_sz); if (!skb) { stats->rx_dropped++; goto find_next_rx; } skb->ip_summed = r8152_rx_csum(tp, rx_desc); - memcpy(skb->data, rx_data, pkt_len); - skb_put(skb, pkt_len); + memcpy(skb->data, rx_data, rx_frag_head_sz); + skb_put(skb, rx_frag_head_sz); + pkt_len -= rx_frag_head_sz; + rx_data += rx_frag_head_sz; + if (pkt_len) { + skb_add_rx_frag(skb, 0, agg->page, + agg_offset(agg, rx_data), + pkt_len, + SKB_DATA_ALIGN(pkt_len)); + get_page(agg->page); + } + skb->protocol = eth_type_trans(skb, netdev); rtl_rx_vlan_tag(rx_desc, skb); if (work_done < budget) { napi_gro_receive(napi, skb); work_done++; stats->rx_packets++; - stats->rx_bytes += pkt_len; + stats->rx_bytes += skb->len; } else { __skb_queue_tail(&tp->rx_queue, skb); } @@ -2042,10 +2102,24 @@ static int rx_bottom(struct r8152 *tp, int budget) find_next_rx: rx_data = rx_agg_align(rx_data + pkt_len + ETH_FCS_LEN); rx_desc = (struct rx_desc *)rx_data; - len_used = (int)(rx_data - (u8 *)agg->buffer); + len_used = agg_offset(agg, rx_data); len_used += sizeof(struct rx_desc); } + WARN_ON(!agg_free && page_count(agg->page) > 1); + + if (agg_free) { + spin_lock_irqsave(&tp->rx_lock, flags); + if (page_count(agg->page) == 1) { + list_add(&agg_free->list, &tp->rx_used); + } else { + list_add_tail(&agg->list, &tp->rx_used); + agg = agg_free; + urb = agg->urb; + } + spin_unlock_irqrestore(&tp->rx_lock, flags); + } + submit: if (!ret) { ret = r8152_submit_rx(tp, agg, GFP_ATOMIC); @@ -2373,13 +2447,14 @@ static int rtl_start_rx(struct r8152 *tp) struct rx_agg *agg, *agg_next; struct list_head tmp_list; unsigned long flags; - int ret = 0; + int ret = 0, i = 0; INIT_LIST_HEAD(&tmp_list); spin_lock_irqsave(&tp->rx_lock, flags); INIT_LIST_HEAD(&tp->rx_done); + INIT_LIST_HEAD(&tp->rx_used); list_splice_init(&tp->rx_info, &tmp_list); @@ -2388,10 +2463,18 @@ static int rtl_start_rx(struct r8152 *tp) list_for_each_entry_safe(agg, agg_next, &tmp_list, info_list) { INIT_LIST_HEAD(&agg->list); - if (ret < 0) + /* Only RTL8152_MAX_RX rx_agg need to be submitted. */ + if (++i > RTL8152_MAX_RX) { + spin_lock_irqsave(&tp->rx_lock, flags); + list_add_tail(&agg->list, &tp->rx_used); + spin_unlock_irqrestore(&tp->rx_lock, flags); + } else if (unlikely(ret < 0)) { + spin_lock_irqsave(&tp->rx_lock, flags); list_add_tail(&agg->list, &tp->rx_done); - else + spin_unlock_irqrestore(&tp->rx_lock, flags); + } else { ret = r8152_submit_rx(tp, agg, GFP_KERNEL); + } } spin_lock_irqsave(&tp->rx_lock, flags); @@ -2420,8 +2503,15 @@ static int rtl_stop_rx(struct r8152 *tp) list_splice_init(&tp->rx_info, &tmp_list); spin_unlock_irqrestore(&tp->rx_lock, flags); - list_for_each_entry_safe(agg, agg_next, &tmp_list, info_list) - usb_kill_urb(agg->urb); + list_for_each_entry_safe(agg, agg_next, &tmp_list, info_list) { + /* At least RTL8152_MAX_RX rx_agg have the page_count being + * equal to 1, so the other ones could be freed safely. + */ + if (page_count(agg->page) > 1) + free_rx_agg(tp, agg); + else + usb_kill_urb(agg->urb); + } /* Move back the list of temp to the rx_info */ spin_lock_irqsave(&tp->rx_lock, flags); -- cgit v1.2.3