static int alloc_sg(struct sock *sk, int len, struct scatterlist *sg,
int *sg_num_elem, unsigned int *sg_size,
int first_coalesce)
{
struct page_frag *pfrag;
unsigned int size = *sg_size;
int num_elem = *sg_num_elem, use = 0, rc = 0;
struct scatterlist *sge;
unsigned int orig_offset;
len -= size;
pfrag = sk_page_frag(sk);
while (len > 0) {
if (!sk_page_frag_refill(sk, pfrag)) {
rc = -ENOMEM;
goto out;
}
use = min_t(int, len, pfrag->size - pfrag->offset);
if (!sk_wmem_schedule(sk, use)) {
rc = -ENOMEM;
goto out;
}
sk_mem_charge(sk, use);
size += use;
orig_offset = pfrag->offset;
pfrag->offset += use;
sge = sg + num_elem - 1;
if (num_elem > first_coalesce && sg_page(sg) == pfrag->page &&
sg->offset + sg->length == orig_offset) {
sg->length += use;
} else {
sge++;
sg_unmark_end(sge);
sg_set_page(sge, pfrag->page, use, orig_offset);
get_page(pfrag->page);
++num_elem;
if (num_elem == MAX_SKB_FRAGS) {
rc = -ENOSPC;
break;
}
}
len -= use;
}
goto out;
out:
*sg_size = size;
*sg_num_elem = num_elem;
return rc;
}
bool rtl_sk_wmem_schedule(struct sock *sk, int size)
{
return sk_wmem_schedule(sk, size);
}
