linux_dsm_epyc7002/include/net/sctp/command.h
David Laight b9420e1c87 net: sctp: Optimise the way 'sctp_arg_t' values are initialised.
Even if memset() is inlined (as on x86) using it to zero the union
generates a memory word write of zero, followed by a write of the
smaller field, and then a read of the word.
As well as being a lot of instructions the sequence is unlikely to
be optimised by the store-load forward hardware so will be slow.

Instead allocate a field of the union that is the same size as the
entire union and write a zero value to it. The compiler will then
generate the required value in a register.

Zeroing the union shouldn't be necessary, but this patch series isn't
intended to have a behavioural change.

Signed-off-by: David Laight <david.laight@aculab.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-08 14:39:00 -07:00

250 lines
9.1 KiB
C

/* SCTP kernel Implementation
* (C) Copyright IBM Corp. 2001, 2004
* Copyright (C) 1999-2001 Cisco, Motorola
*
* This file is part of the SCTP kernel implementation
*
* These are the definitions needed for the command object.
*
* This SCTP implementation is free software;
* you can redistribute it and/or modify it under the terms of
* the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This SCTP implementation is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* ************************
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU CC; see the file COPYING. If not, see
* <http://www.gnu.org/licenses/>.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <linux-sctp@vger.kernel.org>
*
* Written or modified by:
* La Monte H.P. Yarroll <piggy@acm.org>
* Karl Knutson <karl@athena.chicago.il.us>
* Ardelle Fan <ardelle.fan@intel.com>
* Sridhar Samudrala <sri@us.ibm.com>
*/
#ifndef __net_sctp_command_h__
#define __net_sctp_command_h__
#include <net/sctp/constants.h>
#include <net/sctp/structs.h>
typedef enum {
SCTP_CMD_NOP = 0, /* Do nothing. */
SCTP_CMD_NEW_ASOC, /* Register a new association. */
SCTP_CMD_DELETE_TCB, /* Delete the current association. */
SCTP_CMD_NEW_STATE, /* Enter a new state. */
SCTP_CMD_REPORT_TSN, /* Record the arrival of a TSN. */
SCTP_CMD_GEN_SACK, /* Send a Selective ACK (maybe). */
SCTP_CMD_PROCESS_SACK, /* Process an inbound SACK. */
SCTP_CMD_GEN_INIT_ACK, /* Generate an INIT ACK chunk. */
SCTP_CMD_PEER_INIT, /* Process a INIT from the peer. */
SCTP_CMD_GEN_COOKIE_ECHO, /* Generate a COOKIE ECHO chunk. */
SCTP_CMD_CHUNK_ULP, /* Send a chunk to the sockets layer. */
SCTP_CMD_EVENT_ULP, /* Send a notification to the sockets layer. */
SCTP_CMD_REPLY, /* Send a chunk to our peer. */
SCTP_CMD_SEND_PKT, /* Send a full packet to our peer. */
SCTP_CMD_RETRAN, /* Mark a transport for retransmission. */
SCTP_CMD_ECN_CE, /* Do delayed CE processing. */
SCTP_CMD_ECN_ECNE, /* Do delayed ECNE processing. */
SCTP_CMD_ECN_CWR, /* Do delayed CWR processing. */
SCTP_CMD_TIMER_START, /* Start a timer. */
SCTP_CMD_TIMER_START_ONCE, /* Start a timer once */
SCTP_CMD_TIMER_RESTART, /* Restart a timer. */
SCTP_CMD_TIMER_STOP, /* Stop a timer. */
SCTP_CMD_INIT_CHOOSE_TRANSPORT, /* Choose transport for an INIT. */
SCTP_CMD_INIT_COUNTER_RESET, /* Reset init counter. */
SCTP_CMD_INIT_COUNTER_INC, /* Increment init counter. */
SCTP_CMD_INIT_RESTART, /* High level, do init timer work. */
SCTP_CMD_COOKIEECHO_RESTART, /* High level, do cookie-echo timer work. */
SCTP_CMD_INIT_FAILED, /* High level, do init failure work. */
SCTP_CMD_REPORT_DUP, /* Report a duplicate TSN. */
SCTP_CMD_STRIKE, /* Mark a strike against a transport. */
SCTP_CMD_HB_TIMERS_START, /* Start the heartbeat timers. */
SCTP_CMD_HB_TIMER_UPDATE, /* Update a heartbeat timers. */
SCTP_CMD_HB_TIMERS_STOP, /* Stop the heartbeat timers. */
SCTP_CMD_TRANSPORT_HB_SENT, /* Reset the status of a transport. */
SCTP_CMD_TRANSPORT_IDLE, /* Do manipulations on idle transport */
SCTP_CMD_TRANSPORT_ON, /* Mark the transport as active. */
SCTP_CMD_REPORT_ERROR, /* Pass this error back out of the sm. */
SCTP_CMD_REPORT_BAD_TAG, /* Verification tags didn't match. */
SCTP_CMD_PROCESS_CTSN, /* Sideeffect from shutdown. */
SCTP_CMD_ASSOC_FAILED, /* Handle association failure. */
SCTP_CMD_DISCARD_PACKET, /* Discard the whole packet. */
SCTP_CMD_GEN_SHUTDOWN, /* Generate a SHUTDOWN chunk. */
SCTP_CMD_UPDATE_ASSOC, /* Update association information. */
SCTP_CMD_PURGE_OUTQUEUE, /* Purge all data waiting to be sent. */
SCTP_CMD_SETUP_T2, /* Hi-level, setup T2-shutdown parms. */
SCTP_CMD_RTO_PENDING, /* Set transport's rto_pending. */
SCTP_CMD_PART_DELIVER, /* Partial data delivery considerations. */
SCTP_CMD_RENEGE, /* Renege data on an association. */
SCTP_CMD_SETUP_T4, /* ADDIP, setup T4 RTO timer parms. */
SCTP_CMD_PROCESS_OPERR, /* Process an ERROR chunk. */
SCTP_CMD_REPORT_FWDTSN, /* Report new cumulative TSN Ack. */
SCTP_CMD_PROCESS_FWDTSN, /* Skips were reported, so process further. */
SCTP_CMD_CLEAR_INIT_TAG, /* Clears association peer's inittag. */
SCTP_CMD_DEL_NON_PRIMARY, /* Removes non-primary peer transports. */
SCTP_CMD_T3_RTX_TIMERS_STOP, /* Stops T3-rtx pending timers */
SCTP_CMD_FORCE_PRIM_RETRAN, /* Forces retrans. over primary path. */
SCTP_CMD_SET_SK_ERR, /* Set sk_err */
SCTP_CMD_ASSOC_CHANGE, /* generate and send assoc_change event */
SCTP_CMD_ADAPTATION_IND, /* generate and send adaptation event */
SCTP_CMD_ASSOC_SHKEY, /* generate the association shared keys */
SCTP_CMD_T1_RETRAN, /* Mark for retransmission after T1 timeout */
SCTP_CMD_UPDATE_INITTAG, /* Update peer inittag */
SCTP_CMD_SEND_MSG, /* Send the whole use message */
SCTP_CMD_SEND_NEXT_ASCONF, /* Send the next ASCONF after ACK */
SCTP_CMD_PURGE_ASCONF_QUEUE, /* Purge all asconf queues.*/
SCTP_CMD_SET_ASOC, /* Restore association context */
SCTP_CMD_LAST
} sctp_verb_t;
/* How many commands can you put in an sctp_cmd_seq_t?
* This is a rather arbitrary number, ideally derived from a careful
* analysis of the state functions, but in reality just taken from
* thin air in the hopes othat we don't trigger a kernel panic.
*/
#define SCTP_MAX_NUM_COMMANDS 14
typedef union {
void *zero_all; /* Set to NULL to clear the entire union */
__s32 i32;
__u32 u32;
__be32 be32;
__u16 u16;
__u8 u8;
int error;
__be16 err;
sctp_state_t state;
sctp_event_timeout_t to;
struct sctp_chunk *chunk;
struct sctp_association *asoc;
struct sctp_transport *transport;
struct sctp_bind_addr *bp;
sctp_init_chunk_t *init;
struct sctp_ulpevent *ulpevent;
struct sctp_packet *packet;
sctp_sackhdr_t *sackh;
struct sctp_datamsg *msg;
} sctp_arg_t;
/* We are simulating ML type constructors here.
*
* SCTP_ARG_CONSTRUCTOR(NAME, TYPE, ELT) builds a function called
* SCTP_NAME() which takes an argument of type TYPE and returns an
* sctp_arg_t. It does this by inserting the sole argument into the
* ELT union element of a local sctp_arg_t.
*
* E.g., SCTP_ARG_CONSTRUCTOR(I32, __s32, i32) builds SCTP_I32(arg),
* which takes an __s32 and returns a sctp_arg_t containing the
* __s32. So, after foo = SCTP_I32(arg), foo.i32 == arg.
*/
#define SCTP_ARG_CONSTRUCTOR(name, type, elt) \
static inline sctp_arg_t \
SCTP_## name (type arg) \
{ sctp_arg_t retval;\
retval.zero_all = NULL;\
retval.elt = arg;\
return retval;\
}
SCTP_ARG_CONSTRUCTOR(I32, __s32, i32)
SCTP_ARG_CONSTRUCTOR(U32, __u32, u32)
SCTP_ARG_CONSTRUCTOR(BE32, __be32, be32)
SCTP_ARG_CONSTRUCTOR(U16, __u16, u16)
SCTP_ARG_CONSTRUCTOR(U8, __u8, u8)
SCTP_ARG_CONSTRUCTOR(ERROR, int, error)
SCTP_ARG_CONSTRUCTOR(PERR, __be16, err) /* protocol error */
SCTP_ARG_CONSTRUCTOR(STATE, sctp_state_t, state)
SCTP_ARG_CONSTRUCTOR(TO, sctp_event_timeout_t, to)
SCTP_ARG_CONSTRUCTOR(CHUNK, struct sctp_chunk *, chunk)
SCTP_ARG_CONSTRUCTOR(ASOC, struct sctp_association *, asoc)
SCTP_ARG_CONSTRUCTOR(TRANSPORT, struct sctp_transport *, transport)
SCTP_ARG_CONSTRUCTOR(BA, struct sctp_bind_addr *, bp)
SCTP_ARG_CONSTRUCTOR(PEER_INIT, sctp_init_chunk_t *, init)
SCTP_ARG_CONSTRUCTOR(ULPEVENT, struct sctp_ulpevent *, ulpevent)
SCTP_ARG_CONSTRUCTOR(PACKET, struct sctp_packet *, packet)
SCTP_ARG_CONSTRUCTOR(SACKH, sctp_sackhdr_t *, sackh)
SCTP_ARG_CONSTRUCTOR(DATAMSG, struct sctp_datamsg *, msg)
static inline sctp_arg_t SCTP_FORCE(void)
{
return SCTP_I32(1);
}
static inline sctp_arg_t SCTP_NOFORCE(void)
{
return SCTP_I32(0);
}
static inline sctp_arg_t SCTP_NULL(void)
{
sctp_arg_t retval;
retval.zero_all = NULL;
return retval;
}
typedef struct {
sctp_arg_t obj;
sctp_verb_t verb;
} sctp_cmd_t;
typedef struct {
sctp_cmd_t cmds[SCTP_MAX_NUM_COMMANDS];
__u8 next_free_slot;
__u8 next_cmd;
} sctp_cmd_seq_t;
/* Initialize a block of memory as a command sequence.
* Return 0 if the initialization fails.
*/
static inline int sctp_init_cmd_seq(sctp_cmd_seq_t *seq)
{
seq->next_free_slot = 0;
seq->next_cmd = 0;
return 1; /* We always succeed. */
}
/* Add a command to an sctp_cmd_seq_t.
*
* Use the SCTP_* constructors defined by SCTP_ARG_CONSTRUCTOR() above
* to wrap data which goes in the obj argument.
*/
static inline void sctp_add_cmd_sf(sctp_cmd_seq_t *seq, sctp_verb_t verb,
sctp_arg_t obj)
{
BUG_ON(seq->next_free_slot >= SCTP_MAX_NUM_COMMANDS);
seq->cmds[seq->next_free_slot].verb = verb;
seq->cmds[seq->next_free_slot++].obj = obj;
}
/* Return the next command structure in an sctp_cmd_seq.
* Return NULL at the end of the sequence.
*/
static inline sctp_cmd_t *sctp_next_cmd(sctp_cmd_seq_t *seq)
{
sctp_cmd_t *retval = NULL;
if (seq->next_cmd < seq->next_free_slot)
retval = &seq->cmds[seq->next_cmd++];
return retval;
}
#endif /* __net_sctp_command_h__ */