skb->fclone = SKB_FCLONE_ORIG;
atomic_set(&fclones->fclone_ref, 1);
- fclones->skb2.fclone = SKB_FCLONE_FREE;
+ fclones->skb2.fclone = SKB_FCLONE_CLONE;
fclones->skb2.pfmemalloc = pfmemalloc;
}
out:
unsigned int pagecnt_bias;
};
static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache);
+static DEFINE_PER_CPU(struct netdev_alloc_cache, napi_alloc_cache);
-static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
+static struct page *__page_frag_refill(struct netdev_alloc_cache *nc,
+ gfp_t gfp_mask)
{
- struct netdev_alloc_cache *nc;
- void *data = NULL;
- int order;
- unsigned long flags;
+ const unsigned int order = NETDEV_FRAG_PAGE_MAX_ORDER;
+ struct page *page = NULL;
+ gfp_t gfp = gfp_mask;
+
+ if (order) {
+ gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY;
+ page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
+ nc->frag.size = PAGE_SIZE << (page ? order : 0);
+ }
- local_irq_save(flags);
- nc = this_cpu_ptr(&netdev_alloc_cache);
- if (unlikely(!nc->frag.page)) {
+ if (unlikely(!page))
+ page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
+
+ nc->frag.page = page;
+
+ return page;
+}
+
+static void *__alloc_page_frag(struct netdev_alloc_cache __percpu *cache,
+ unsigned int fragsz, gfp_t gfp_mask)
+{
+ struct netdev_alloc_cache *nc = this_cpu_ptr(cache);
+ struct page *page = nc->frag.page;
+ unsigned int size;
+ int offset;
+
+ if (unlikely(!page)) {
refill:
- for (order = NETDEV_FRAG_PAGE_MAX_ORDER; ;) {
- gfp_t gfp = gfp_mask;
+ page = __page_frag_refill(nc, gfp_mask);
+ if (!page)
+ return NULL;
+
+ /* if size can vary use frag.size else just use PAGE_SIZE */
+ size = NETDEV_FRAG_PAGE_MAX_ORDER ? nc->frag.size : PAGE_SIZE;
- if (order)
- gfp |= __GFP_COMP | __GFP_NOWARN;
- nc->frag.page = alloc_pages(gfp, order);
- if (likely(nc->frag.page))
- break;
- if (--order < 0)
- goto end;
- }
- nc->frag.size = PAGE_SIZE << order;
/* Even if we own the page, we do not use atomic_set().
* This would break get_page_unless_zero() users.
*/
- atomic_add(NETDEV_PAGECNT_MAX_BIAS - 1,
- &nc->frag.page->_count);
- nc->pagecnt_bias = NETDEV_PAGECNT_MAX_BIAS;
- nc->frag.offset = 0;
+ atomic_add(size - 1, &page->_count);
+
+ /* reset page count bias and offset to start of new frag */
+ nc->pagecnt_bias = size;
+ nc->frag.offset = size;
}
- if (nc->frag.offset + fragsz > nc->frag.size) {
- if (atomic_read(&nc->frag.page->_count) != nc->pagecnt_bias) {
- if (!atomic_sub_and_test(nc->pagecnt_bias,
- &nc->frag.page->_count))
- goto refill;
- /* OK, page count is 0, we can safely set it */
- atomic_set(&nc->frag.page->_count,
- NETDEV_PAGECNT_MAX_BIAS);
- } else {
- atomic_add(NETDEV_PAGECNT_MAX_BIAS - nc->pagecnt_bias,
- &nc->frag.page->_count);
- }
- nc->pagecnt_bias = NETDEV_PAGECNT_MAX_BIAS;
- nc->frag.offset = 0;
+ offset = nc->frag.offset - fragsz;
+ if (unlikely(offset < 0)) {
+ if (!atomic_sub_and_test(nc->pagecnt_bias, &page->_count))
+ goto refill;
+
+ /* if size can vary use frag.size else just use PAGE_SIZE */
+ size = NETDEV_FRAG_PAGE_MAX_ORDER ? nc->frag.size : PAGE_SIZE;
+
+ /* OK, page count is 0, we can safely set it */
+ atomic_set(&page->_count, size);
+
+ /* reset page count bias and offset to start of new frag */
+ nc->pagecnt_bias = size;
+ offset = size - fragsz;
}
- data = page_address(nc->frag.page) + nc->frag.offset;
- nc->frag.offset += fragsz;
nc->pagecnt_bias--;
-end:
+ nc->frag.offset = offset;
+
+ return page_address(page) + offset;
+}
+
+static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
+{
+ unsigned long flags;
+ void *data;
+
+ local_irq_save(flags);
+ data = __alloc_page_frag(&netdev_alloc_cache, fragsz, gfp_mask);
local_irq_restore(flags);
return data;
}
}
EXPORT_SYMBOL(netdev_alloc_frag);
+static void *__napi_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
+{
+ return __alloc_page_frag(&napi_alloc_cache, fragsz, gfp_mask);
+}
+
+void *napi_alloc_frag(unsigned int fragsz)
+{
+ return __napi_alloc_frag(fragsz, GFP_ATOMIC | __GFP_COLD);
+}
+EXPORT_SYMBOL(napi_alloc_frag);
+
/**
- * __netdev_alloc_skb - allocate an skbuff for rx on a specific device
- * @dev: network device to receive on
+ * __alloc_rx_skb - allocate an skbuff for rx
* @length: length to allocate
* @gfp_mask: get_free_pages mask, passed to alloc_skb
+ * @flags: If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for
+ * allocations in case we have to fallback to __alloc_skb()
+ * If SKB_ALLOC_NAPI is set, page fragment will be allocated
+ * from napi_cache instead of netdev_cache.
*
* Allocate a new &sk_buff and assign it a usage count of one. The
* buffer has unspecified headroom built in. Users should allocate
*
* %NULL is returned if there is no free memory.
*/
-struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
- unsigned int length, gfp_t gfp_mask)
+static struct sk_buff *__alloc_rx_skb(unsigned int length, gfp_t gfp_mask,
+ int flags)
{
struct sk_buff *skb = NULL;
- unsigned int fragsz = SKB_DATA_ALIGN(length + NET_SKB_PAD) +
+ unsigned int fragsz = SKB_DATA_ALIGN(length) +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
if (fragsz <= PAGE_SIZE && !(gfp_mask & (__GFP_WAIT | GFP_DMA))) {
if (sk_memalloc_socks())
gfp_mask |= __GFP_MEMALLOC;
- data = __netdev_alloc_frag(fragsz, gfp_mask);
+ data = (flags & SKB_ALLOC_NAPI) ?
+ __napi_alloc_frag(fragsz, gfp_mask) :
+ __netdev_alloc_frag(fragsz, gfp_mask);
if (likely(data)) {
skb = build_skb(data, fragsz);
put_page(virt_to_head_page(data));
}
} else {
- skb = __alloc_skb(length + NET_SKB_PAD, gfp_mask,
+ skb = __alloc_skb(length, gfp_mask,
SKB_ALLOC_RX, NUMA_NO_NODE);
}
+ return skb;
+}
+
+/**
+ * __netdev_alloc_skb - allocate an skbuff for rx on a specific device
+ * @dev: network device to receive on
+ * @length: length to allocate
+ * @gfp_mask: get_free_pages mask, passed to alloc_skb
+ *
+ * Allocate a new &sk_buff and assign it a usage count of one. The
+ * buffer has NET_SKB_PAD headroom built in. Users should allocate
+ * the headroom they think they need without accounting for the
+ * built in space. The built in space is used for optimisations.
+ *
+ * %NULL is returned if there is no free memory.
+ */
+struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
+ unsigned int length, gfp_t gfp_mask)
+{
+ struct sk_buff *skb;
+
+ length += NET_SKB_PAD;
+ skb = __alloc_rx_skb(length, gfp_mask, 0);
+
if (likely(skb)) {
skb_reserve(skb, NET_SKB_PAD);
skb->dev = dev;
}
+
return skb;
}
EXPORT_SYMBOL(__netdev_alloc_skb);
+/**
+ * __napi_alloc_skb - allocate skbuff for rx in a specific NAPI instance
+ * @napi: napi instance this buffer was allocated for
+ * @length: length to allocate
+ * @gfp_mask: get_free_pages mask, passed to alloc_skb and alloc_pages
+ *
+ * Allocate a new sk_buff for use in NAPI receive. This buffer will
+ * attempt to allocate the head from a special reserved region used
+ * only for NAPI Rx allocation. By doing this we can save several
+ * CPU cycles by avoiding having to disable and re-enable IRQs.
+ *
+ * %NULL is returned if there is no free memory.
+ */
+struct sk_buff *__napi_alloc_skb(struct napi_struct *napi,
+ unsigned int length, gfp_t gfp_mask)
+{
+ struct sk_buff *skb;
+
+ length += NET_SKB_PAD + NET_IP_ALIGN;
+ skb = __alloc_rx_skb(length, gfp_mask, SKB_ALLOC_NAPI);
+
+ if (likely(skb)) {
+ skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
+ skb->dev = napi->dev;
+ }
+
+ return skb;
+}
+EXPORT_SYMBOL(__napi_alloc_skb);
+
void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
int size, unsigned int truesize)
{
switch (skb->fclone) {
case SKB_FCLONE_UNAVAILABLE:
kmem_cache_free(skbuff_head_cache, skb);
- break;
+ return;
case SKB_FCLONE_ORIG:
fclones = container_of(skb, struct sk_buff_fclones, skb1);
- if (atomic_dec_and_test(&fclones->fclone_ref))
- kmem_cache_free(skbuff_fclone_cache, fclones);
+
+ /* We usually free the clone (TX completion) before original skb
+ * This test would have no chance to be true for the clone,
+ * while here, branch prediction will be good.
+ */
+ if (atomic_read(&fclones->fclone_ref) == 1)
+ goto fastpath;
break;
- case SKB_FCLONE_CLONE:
+ default: /* SKB_FCLONE_CLONE */
fclones = container_of(skb, struct sk_buff_fclones, skb2);
-
- /* Warning : We must perform the atomic_dec_and_test() before
- * setting skb->fclone back to SKB_FCLONE_FREE, otherwise
- * skb_clone() could set clone_ref to 2 before our decrement.
- * Anyway, if we are going to free the structure, no need to
- * rewrite skb->fclone.
- */
- if (atomic_dec_and_test(&fclones->fclone_ref)) {
- kmem_cache_free(skbuff_fclone_cache, fclones);
- } else {
- /* The clone portion is available for
- * fast-cloning again.
- */
- skb->fclone = SKB_FCLONE_FREE;
- }
break;
}
+ if (!atomic_dec_and_test(&fclones->fclone_ref))
+ return;
+fastpath:
+ kmem_cache_free(skbuff_fclone_cache, fclones);
}
static void skb_release_head_state(struct sk_buff *skb)
struct sk_buff_fclones *fclones = container_of(skb,
struct sk_buff_fclones,
skb1);
- struct sk_buff *n = &fclones->skb2;
+ struct sk_buff *n;
if (skb_orphan_frags(skb, gfp_mask))
return NULL;
if (skb->fclone == SKB_FCLONE_ORIG &&
- n->fclone == SKB_FCLONE_FREE) {
- n->fclone = SKB_FCLONE_CLONE;
- /* As our fastclone was free, clone_ref must be 1 at this point.
- * We could use atomic_inc() here, but it is faster
- * to set the final value.
- */
+ atomic_read(&fclones->fclone_ref) == 1) {
+ n = &fclones->skb2;
atomic_set(&fclones->fclone_ref, 2);
} else {
if (skb_pfmemalloc(skb))
if (nskb->len == len + doffset)
goto perform_csum_check;
- if (!sg) {
+ if (!sg && !nskb->remcsum_offload) {
nskb->ip_summed = CHECKSUM_NONE;
nskb->csum = skb_copy_and_csum_bits(head_skb, offset,
skb_put(nskb, len),
nskb->truesize += nskb->data_len;
perform_csum_check:
- if (!csum) {
+ if (!csum && !nskb->remcsum_offload) {
nskb->csum = skb_checksum(nskb, doffset,
nskb->len - doffset, 0);
nskb->ip_summed = CHECKSUM_NONE;
* (see validate_xmit_skb_list() for example)
*/
segs->prev = tail;
+
+ /* Following permits correct backpressure, for protocols
+ * using skb_set_owner_w().
+ * Idea is to tranfert ownership from head_skb to last segment.
+ */
+ if (head_skb->destructor == sock_wfree) {
+ swap(tail->truesize, head_skb->truesize);
+ swap(tail->destructor, head_skb->destructor);
+ swap(tail->sk, head_skb->sk);
+ }
return segs;
err:
}
EXPORT_SYMBOL(skb_vlan_untag);
+int skb_ensure_writable(struct sk_buff *skb, int write_len)
+{
+ if (!pskb_may_pull(skb, write_len))
+ return -ENOMEM;
+
+ if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
+ return 0;
+
+ return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+}
+EXPORT_SYMBOL(skb_ensure_writable);
+
+/* remove VLAN header from packet and update csum accordingly. */
+static int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci)
+{
+ struct vlan_hdr *vhdr;
+ unsigned int offset = skb->data - skb_mac_header(skb);
+ int err;
+
+ __skb_push(skb, offset);
+ err = skb_ensure_writable(skb, VLAN_ETH_HLEN);
+ if (unlikely(err))
+ goto pull;
+
+ skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);
+
+ vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
+ *vlan_tci = ntohs(vhdr->h_vlan_TCI);
+
+ memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
+ __skb_pull(skb, VLAN_HLEN);
+
+ vlan_set_encap_proto(skb, vhdr);
+ skb->mac_header += VLAN_HLEN;
+
+ if (skb_network_offset(skb) < ETH_HLEN)
+ skb_set_network_header(skb, ETH_HLEN);
+
+ skb_reset_mac_len(skb);
+pull:
+ __skb_pull(skb, offset);
+
+ return err;
+}
+
+int skb_vlan_pop(struct sk_buff *skb)
+{
+ u16 vlan_tci;
+ __be16 vlan_proto;
+ int err;
+
+ if (likely(vlan_tx_tag_present(skb))) {
+ skb->vlan_tci = 0;
+ } else {
+ if (unlikely((skb->protocol != htons(ETH_P_8021Q) &&
+ skb->protocol != htons(ETH_P_8021AD)) ||
+ skb->len < VLAN_ETH_HLEN))
+ return 0;
+
+ err = __skb_vlan_pop(skb, &vlan_tci);
+ if (err)
+ return err;
+ }
+ /* move next vlan tag to hw accel tag */
+ if (likely((skb->protocol != htons(ETH_P_8021Q) &&
+ skb->protocol != htons(ETH_P_8021AD)) ||
+ skb->len < VLAN_ETH_HLEN))
+ return 0;
+
+ vlan_proto = skb->protocol;
+ err = __skb_vlan_pop(skb, &vlan_tci);
+ if (unlikely(err))
+ return err;
+
+ __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
+ return 0;
+}
+EXPORT_SYMBOL(skb_vlan_pop);
+
+int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
+{
+ if (vlan_tx_tag_present(skb)) {
+ unsigned int offset = skb->data - skb_mac_header(skb);
+ int err;
+
+ /* __vlan_insert_tag expect skb->data pointing to mac header.
+ * So change skb->data before calling it and change back to
+ * original position later
+ */
+ __skb_push(skb, offset);
+ err = __vlan_insert_tag(skb, skb->vlan_proto,
+ vlan_tx_tag_get(skb));
+ if (err)
+ return err;
+ skb->protocol = skb->vlan_proto;
+ skb->mac_len += VLAN_HLEN;
+ __skb_pull(skb, offset);
+
+ if (skb->ip_summed == CHECKSUM_COMPLETE)
+ skb->csum = csum_add(skb->csum, csum_partial(skb->data
+ + (2 * ETH_ALEN), VLAN_HLEN, 0));
+ }
+ __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
+ return 0;
+}
+EXPORT_SYMBOL(skb_vlan_push);
+
/**
* alloc_skb_with_frags - allocate skb with page frags
*
projects / cascardo / linux.git / blobdiff