diff options
Diffstat (limited to 'include/linux/skbuff.h')
| -rw-r--r-- | include/linux/skbuff.h | 36 |
1 files changed, 24 insertions, 12 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index a3ff380d43f0..6787fcf6ac3e 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -358,6 +358,12 @@ struct sk_buff; */ #define GSO_BY_FRAGS 0xFFFF +/* All frags in an skb must either all be struct page-backed or all belong to + * the same memory provider instance (e.g. the same devmem binding or io_uring + * area). Mixing page and memory-provider frags, or mixing frags from different + * memory providers within a single skb (including via coalescing), is not + * allowed. + */ typedef struct skb_frag { netmem_ref netmem; unsigned int len; @@ -633,9 +639,9 @@ struct skb_shared_info { * * Transport layers send out clones of payload skbs they hold for * retransmissions. To allow lower layers of the stack to prepend their headers - * we split &skb_shared_info.dataref into two halves. - * The lower 16 bits count the overall number of references. - * The higher 16 bits indicate how many of the references are payload-only. + * we split &skb_shared_info.dataref into two parts. + * The lower 30 bits count the overall number of references. + * Bit 30 indicates whether one of the references is payload-only. * skb_header_cloned() checks if skb is allowed to add / write the headers. * * The creator of the skb (e.g. TCP) marks its skb as &sk_buff.nohdr @@ -655,7 +661,7 @@ struct skb_shared_info { * Having multiple payload-only skbs with different lengths of hdr_len is not * possible. The payload-only skbs should never leave their owner. */ -#define SKB_DATAREF_SHIFT 16 +#define SKB_DATAREF_SHIFT 30 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) @@ -1036,8 +1042,6 @@ struct sk_buff { __u16 tc_index; /* traffic control index */ #endif - u16 alloc_cpu; - union { __wsum csum; struct { @@ -1088,6 +1092,8 @@ struct sk_buff { ); /* end headers group */ + u16 alloc_cpu; + /* These elements must be at the end, see alloc_skb() for details. */ sk_buff_data_t tail; sk_buff_data_t end; @@ -2125,14 +2131,14 @@ static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri) } /* - * Copy shared buffers into a new sk_buff. We effectively do COW on + * Copy cloned buffers into a new sk_buff. We effectively do COW on * packets to handle cases where we have a local reader and forward * and a couple of other messy ones. The normal one is tcpdumping * a packet that's being forwarded. */ /** - * skb_unshare - make a copy of a shared buffer + * skb_unclone_full - make a private copy of a cloned buffer * @skb: buffer to check * @pri: priority for memory allocation * @@ -2142,10 +2148,13 @@ static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri) * the original buffer is returned. When called with a spinlock held or * from interrupt state @pri must be %GFP_ATOMIC * + * Unlike skb_unclone(), the paged data is copied as well. A buffer with + * skb->users > 1 that is not a clone is returned as is, use + * skb_share_check() for that case. + * * %NULL is returned on a memory allocation failure. */ -static inline struct sk_buff *skb_unshare(struct sk_buff *skb, - gfp_t pri) +static inline struct sk_buff *skb_unclone_full(struct sk_buff *skb, gfp_t pri) { might_sleep_if(gfpflags_allow_blocking(pri)); if (skb_cloned(skb)) { @@ -3816,9 +3825,12 @@ static inline dma_addr_t __skb_frag_dma_map(struct device *dev, size_t offset, size_t size, enum dma_data_direction dir) { + dma_addr_t addr; + if (skb_frag_is_net_iov(frag)) { - return netmem_to_net_iov(frag->netmem)->desc.dma_addr + - offset + frag->offset; + addr = netmem_dma_addr_decode( + netmem_get_dma_addr(frag->netmem)); + return addr + offset + frag->offset; } return dma_map_page(dev, skb_frag_page(frag), skb_frag_off(frag) + offset, size, dir); |