net/packet: constify prb_lookup_block() and __tpacket_v3_has_room()

Goal is to be able to use __tpacket_v3_has_room() without holding
a lock.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2019-06-12 09:52:28 -07:00 коммит произвёл David S. Miller
Родитель d4b5bd98fa
Коммит dcf70cefaf
1 изменённых файлов: 7 добавлений и 7 удалений

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@ -1082,10 +1082,10 @@ static void *packet_current_rx_frame(struct packet_sock *po,
}
}
static void *prb_lookup_block(struct packet_sock *po,
struct packet_ring_buffer *rb,
unsigned int idx,
int status)
static void *prb_lookup_block(const struct packet_sock *po,
const struct packet_ring_buffer *rb,
unsigned int idx,
int status)
{
struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
@ -1211,12 +1211,12 @@ static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
}
static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off)
static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
{
int idx, len;
len = po->rx_ring.prb_bdqc.knum_blocks;
idx = po->rx_ring.prb_bdqc.kactive_blk_num;
len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks);
idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num);
if (pow_off)
idx += len >> pow_off;
if (idx >= len)