/*
* Similar to rss_m2cpuid, but designed to be used by the IP NETISR
* on incoming frames.
*
* If an existing RSS hash exists and it matches what the configured
* hashing is, then use it.
*
* If there's an existing RSS hash but the desired hash is different,
* or if there's no useful RSS hash, then calculate it via
* the software path.
*
* XXX TODO: definitely want statistics here!
*/
struct mbuf *
rss_soft_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid)
{
uint32_t hash_val, hash_type;
int ret;
M_ASSERTPKTHDR(m);
ret = rss_mbuf_software_hash_v4(m, RSS_HASH_PKT_INGRESS,
&hash_val, &hash_type);
if (ret > 0) {
/* mbuf has a valid hash already; don't need to modify it */
*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
} else if (ret == 0) {
/* hash was done; update */
m->m_pkthdr.flowid = hash_val;
M_HASHTYPE_SET(m, hash_type);
m->m_flags |= M_FLOWID;
*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
} else { /* ret < 0 */
/* no hash was done */
*cpuid = NETISR_CPUID_NONE;
}
return (m);
}
/*
* Map the given inp to a CPU id.
*
* This queries RSS if it's compiled in, else it defaults to the current
* CPU ID.
*/
static inline int
inp_to_cpuid(struct inpcb *inp)
{
u_int cpuid;
#ifdef RSS
if (per_cpu_timers) {
cpuid = rss_hash2cpuid(inp->inp_flowid, inp->inp_flowtype);
if (cpuid == NETISR_CPUID_NONE)
return (curcpu); /* XXX */
else
return (cpuid);
}
#else
/* Legacy, pre-RSS behaviour */
if (per_cpu_timers) {
/*
* We don't have a flowid -> cpuid mapping, so cheat and
* just map unknown cpuids to curcpu. Not the best, but
* apparently better than defaulting to swi 0.
*/
cpuid = inp->inp_flowid % (mp_maxid + 1);
if (! CPU_ABSENT(cpuid))
return (cpuid);
return (curcpu);
}
#endif
/* Default for RSS and non-RSS - cpuid 0 */
else {
return (0);
}
}
/*
* netisr CPU affinity lookup routine for use by protocols.
*/
struct mbuf *
rss_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid)
{
M_ASSERTPKTHDR(m);
*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
return (m);
}
