346 lines
13 KiB
C
346 lines
13 KiB
C
|
|
/*
|
|
*
|
|
* Copyright (c) 2004-2007 Atheros Communications Inc.
|
|
* All rights reserved.
|
|
*
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation;
|
|
*
|
|
* Software distributed under the License is distributed on an "AS
|
|
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
|
|
* implied. See the License for the specific language governing
|
|
* rights and limitations under the License.
|
|
*
|
|
*
|
|
*
|
|
*/
|
|
|
|
#include "a_config.h"
|
|
#include "athdefs.h"
|
|
#include "a_types.h"
|
|
#include "a_osapi.h"
|
|
#include "a_debug.h"
|
|
#include "htc_api.h"
|
|
#include "common_drv.h"
|
|
|
|
/********* CREDIT DISTRIBUTION FUNCTIONS ******************************************/
|
|
|
|
#define NO_VO_SERVICE 1 /* currently WMI only uses 3 data streams, so we leave VO service inactive */
|
|
|
|
#ifdef NO_VO_SERVICE
|
|
#define DATA_SVCS_USED 3
|
|
#else
|
|
#define DATA_SVCS_USED 4
|
|
#endif
|
|
|
|
static void RedistributeCredits(COMMON_CREDIT_STATE_INFO *pCredInfo,
|
|
HTC_ENDPOINT_CREDIT_DIST *pEPDistList);
|
|
|
|
static void SeekCredits(COMMON_CREDIT_STATE_INFO *pCredInfo,
|
|
HTC_ENDPOINT_CREDIT_DIST *pEPDistList);
|
|
|
|
/* reduce an ep's credits back to a set limit */
|
|
static INLINE void ReduceCredits(COMMON_CREDIT_STATE_INFO *pCredInfo,
|
|
HTC_ENDPOINT_CREDIT_DIST *pEpDist,
|
|
int Limit)
|
|
{
|
|
int credits;
|
|
|
|
/* set the new limit */
|
|
pEpDist->TxCreditsAssigned = Limit;
|
|
|
|
if (pEpDist->TxCredits <= Limit) {
|
|
return;
|
|
}
|
|
|
|
/* figure out how much to take away */
|
|
credits = pEpDist->TxCredits - Limit;
|
|
/* take them away */
|
|
pEpDist->TxCredits -= credits;
|
|
pCredInfo->CurrentFreeCredits += credits;
|
|
}
|
|
|
|
/* give an endpoint some credits from the free credit pool */
|
|
#define GiveCredits(pCredInfo,pEpDist,credits) \
|
|
{ \
|
|
(pEpDist)->TxCredits += (credits); \
|
|
(pEpDist)->TxCreditsAssigned += (credits); \
|
|
(pCredInfo)->CurrentFreeCredits -= (credits); \
|
|
}
|
|
|
|
|
|
/* default credit init callback.
|
|
* This function is called in the context of HTCStart() to setup initial (application-specific)
|
|
* credit distributions */
|
|
static void ar6000_credit_init(void *Context,
|
|
HTC_ENDPOINT_CREDIT_DIST *pEPList,
|
|
int TotalCredits)
|
|
{
|
|
HTC_ENDPOINT_CREDIT_DIST *pCurEpDist;
|
|
int count;
|
|
COMMON_CREDIT_STATE_INFO *pCredInfo = (COMMON_CREDIT_STATE_INFO *)Context;
|
|
|
|
pCredInfo->CurrentFreeCredits = TotalCredits;
|
|
pCredInfo->TotalAvailableCredits = TotalCredits;
|
|
|
|
pCurEpDist = pEPList;
|
|
|
|
/* run through the list and initialize */
|
|
while (pCurEpDist != NULL) {
|
|
|
|
/* set minimums for each endpoint */
|
|
pCurEpDist->TxCreditsMin = pCurEpDist->TxCreditsPerMaxMsg;
|
|
|
|
if (pCurEpDist->ServiceID == WMI_CONTROL_SVC) {
|
|
/* give control service some credits */
|
|
GiveCredits(pCredInfo,pCurEpDist,pCurEpDist->TxCreditsMin);
|
|
/* control service is always marked active, it never goes inactive EVER */
|
|
SET_EP_ACTIVE(pCurEpDist);
|
|
} else if (pCurEpDist->ServiceID == WMI_DATA_BK_SVC) {
|
|
/* this is the lowest priority data endpoint, save this off for easy access */
|
|
pCredInfo->pLowestPriEpDist = pCurEpDist;
|
|
}
|
|
|
|
/* Streams have to be created (explicit | implicit)for all kinds
|
|
* of traffic. BE endpoints are also inactive in the beginning.
|
|
* When BE traffic starts it creates implicit streams that
|
|
* redistributes credits.
|
|
*/
|
|
|
|
/* note, all other endpoints have minimums set but are initially given NO credits.
|
|
* Credits will be distributed as traffic activity demands */
|
|
pCurEpDist = pCurEpDist->pNext;
|
|
}
|
|
|
|
if (pCredInfo->CurrentFreeCredits <= 0) {
|
|
AR_DEBUG_PRINTF(ATH_LOG_INF, ("Not enough credits (%d) to do credit distributions \n", TotalCredits));
|
|
A_ASSERT(FALSE);
|
|
return;
|
|
}
|
|
|
|
/* reset list */
|
|
pCurEpDist = pEPList;
|
|
/* now run through the list and set max operating credit limits for everyone */
|
|
while (pCurEpDist != NULL) {
|
|
if (pCurEpDist->ServiceID == WMI_CONTROL_SVC) {
|
|
/* control service max is just 1 max message */
|
|
pCurEpDist->TxCreditsNorm = pCurEpDist->TxCreditsPerMaxMsg;
|
|
} else {
|
|
/* for the remaining data endpoints, we assume that each TxCreditsPerMaxMsg are
|
|
* the same.
|
|
* We use a simple calculation here, we take the remaining credits and
|
|
* determine how many max messages this can cover and then set each endpoint's
|
|
* normal value equal to half this amount.
|
|
* */
|
|
count = (pCredInfo->CurrentFreeCredits/pCurEpDist->TxCreditsPerMaxMsg) * pCurEpDist->TxCreditsPerMaxMsg;
|
|
count = count >> 1;
|
|
count = max(count,pCurEpDist->TxCreditsPerMaxMsg);
|
|
/* set normal */
|
|
pCurEpDist->TxCreditsNorm = count;
|
|
|
|
}
|
|
pCurEpDist = pCurEpDist->pNext;
|
|
}
|
|
|
|
}
|
|
|
|
|
|
/* default credit distribution callback
|
|
* This callback is invoked whenever endpoints require credit distributions.
|
|
* A lock is held while this function is invoked, this function shall NOT block.
|
|
* The pEPDistList is a list of distribution structures in prioritized order as
|
|
* defined by the call to the HTCSetCreditDistribution() api.
|
|
*
|
|
*/
|
|
static void ar6000_credit_distribute(void *Context,
|
|
HTC_ENDPOINT_CREDIT_DIST *pEPDistList,
|
|
HTC_CREDIT_DIST_REASON Reason)
|
|
{
|
|
HTC_ENDPOINT_CREDIT_DIST *pCurEpDist;
|
|
COMMON_CREDIT_STATE_INFO *pCredInfo = (COMMON_CREDIT_STATE_INFO *)Context;
|
|
|
|
switch (Reason) {
|
|
case HTC_CREDIT_DIST_SEND_COMPLETE :
|
|
pCurEpDist = pEPDistList;
|
|
/* we are given the start of the endpoint distribution list.
|
|
* There may be one or more endpoints to service.
|
|
* Run through the list and distribute credits */
|
|
while (pCurEpDist != NULL) {
|
|
|
|
if (pCurEpDist->TxCreditsToDist > 0) {
|
|
/* return the credits back to the endpoint */
|
|
pCurEpDist->TxCredits += pCurEpDist->TxCreditsToDist;
|
|
/* always zero out when we are done */
|
|
pCurEpDist->TxCreditsToDist = 0;
|
|
|
|
if (pCurEpDist->TxCredits > pCurEpDist->TxCreditsAssigned) {
|
|
/* reduce to the assigned limit, previous credit reductions
|
|
* could have caused the limit to change */
|
|
ReduceCredits(pCredInfo, pCurEpDist, pCurEpDist->TxCreditsAssigned);
|
|
}
|
|
|
|
if (pCurEpDist->TxCredits > pCurEpDist->TxCreditsNorm) {
|
|
/* oversubscribed endpoints need to reduce back to normal */
|
|
ReduceCredits(pCredInfo, pCurEpDist, pCurEpDist->TxCreditsNorm);
|
|
}
|
|
}
|
|
|
|
pCurEpDist = pCurEpDist->pNext;
|
|
}
|
|
|
|
A_ASSERT(pCredInfo->CurrentFreeCredits <= pCredInfo->TotalAvailableCredits);
|
|
|
|
break;
|
|
|
|
case HTC_CREDIT_DIST_ACTIVITY_CHANGE :
|
|
RedistributeCredits(pCredInfo,pEPDistList);
|
|
break;
|
|
case HTC_CREDIT_DIST_SEEK_CREDITS :
|
|
SeekCredits(pCredInfo,pEPDistList);
|
|
break;
|
|
case HTC_DUMP_CREDIT_STATE :
|
|
AR_DEBUG_PRINTF(ATH_LOG_INF, ("Credit Distribution, total : %d, free : %d\n",
|
|
pCredInfo->TotalAvailableCredits, pCredInfo->CurrentFreeCredits));
|
|
break;
|
|
default:
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/* redistribute credits based on activity change */
|
|
static void RedistributeCredits(COMMON_CREDIT_STATE_INFO *pCredInfo,
|
|
HTC_ENDPOINT_CREDIT_DIST *pEPDistList)
|
|
{
|
|
HTC_ENDPOINT_CREDIT_DIST *pCurEpDist = pEPDistList;
|
|
|
|
/* walk through the list and remove credits from inactive endpoints */
|
|
while (pCurEpDist != NULL) {
|
|
|
|
if (pCurEpDist->ServiceID != WMI_CONTROL_SVC) {
|
|
if (!IS_EP_ACTIVE(pCurEpDist)) {
|
|
/* EP is inactive, reduce credits back to zero */
|
|
ReduceCredits(pCredInfo, pCurEpDist, 0);
|
|
}
|
|
}
|
|
|
|
/* NOTE in the active case, we do not need to do anything further,
|
|
* when an EP goes active and needs credits, HTC will call into
|
|
* our distribution function using a reason code of HTC_CREDIT_DIST_SEEK_CREDITS */
|
|
|
|
pCurEpDist = pCurEpDist->pNext;
|
|
}
|
|
|
|
A_ASSERT(pCredInfo->CurrentFreeCredits <= pCredInfo->TotalAvailableCredits);
|
|
|
|
}
|
|
|
|
/* HTC has an endpoint that needs credits, pEPDist is the endpoint in question */
|
|
static void SeekCredits(COMMON_CREDIT_STATE_INFO *pCredInfo,
|
|
HTC_ENDPOINT_CREDIT_DIST *pEPDist)
|
|
{
|
|
HTC_ENDPOINT_CREDIT_DIST *pCurEpDist;
|
|
int credits = 0;
|
|
int need;
|
|
|
|
do {
|
|
|
|
if (pEPDist->ServiceID == WMI_CONTROL_SVC) {
|
|
/* we never oversubscribe on the control service, this is not
|
|
* a high performance path and the target never holds onto control
|
|
* credits for too long */
|
|
break;
|
|
}
|
|
|
|
/* for all other services, we follow a simple algorithm of
|
|
* 1. checking the free pool for credits
|
|
* 2. checking lower priority endpoints for credits to take */
|
|
|
|
if (pCredInfo->CurrentFreeCredits >= 2 * pEPDist->TxCreditsSeek) {
|
|
/* try to give more credits than it needs */
|
|
credits = 2 * pEPDist->TxCreditsSeek;
|
|
} else {
|
|
/* give what we can */
|
|
credits = min(pCredInfo->CurrentFreeCredits,pEPDist->TxCreditsSeek);
|
|
}
|
|
|
|
if (credits >= pEPDist->TxCreditsSeek) {
|
|
/* we found some to fullfill the seek request */
|
|
break;
|
|
}
|
|
|
|
/* we don't have enough in the free pool, try taking away from lower priority services
|
|
*
|
|
* The rule for taking away credits:
|
|
* 1. Only take from lower priority endpoints
|
|
* 2. Only take what is allocated above the minimum (never starve an endpoint completely)
|
|
* 3. Only take what you need.
|
|
*
|
|
* */
|
|
|
|
/* starting at the lowest priority */
|
|
pCurEpDist = pCredInfo->pLowestPriEpDist;
|
|
|
|
/* work backwards until we hit the endpoint again */
|
|
while (pCurEpDist != pEPDist) {
|
|
/* calculate how many we need so far */
|
|
need = pEPDist->TxCreditsSeek - pCredInfo->CurrentFreeCredits;
|
|
|
|
if ((pCurEpDist->TxCreditsAssigned - need) > pCurEpDist->TxCreditsMin) {
|
|
/* the current one has been allocated more than it's minimum and it
|
|
* has enough credits assigned above it's minimum to fullfill our need
|
|
* try to take away just enough to fullfill our need */
|
|
ReduceCredits(pCredInfo,
|
|
pCurEpDist,
|
|
pCurEpDist->TxCreditsAssigned - need);
|
|
|
|
if (pCredInfo->CurrentFreeCredits >= pEPDist->TxCreditsSeek) {
|
|
/* we have enough */
|
|
break;
|
|
}
|
|
}
|
|
|
|
pCurEpDist = pCurEpDist->pPrev;
|
|
}
|
|
|
|
/* return what we can get */
|
|
credits = min(pCredInfo->CurrentFreeCredits,pEPDist->TxCreditsSeek);
|
|
|
|
} while (FALSE);
|
|
|
|
/* did we find some credits? */
|
|
if (credits) {
|
|
/* give what we can */
|
|
GiveCredits(pCredInfo, pEPDist, credits);
|
|
}
|
|
|
|
}
|
|
|
|
/* initialize and setup credit distribution */
|
|
A_STATUS ar6000_setup_credit_dist(HTC_HANDLE HTCHandle, COMMON_CREDIT_STATE_INFO *pCredInfo)
|
|
{
|
|
HTC_SERVICE_ID servicepriority[5];
|
|
|
|
A_MEMZERO(pCredInfo,sizeof(COMMON_CREDIT_STATE_INFO));
|
|
|
|
servicepriority[0] = WMI_CONTROL_SVC; /* highest */
|
|
servicepriority[1] = WMI_DATA_VO_SVC;
|
|
servicepriority[2] = WMI_DATA_VI_SVC;
|
|
servicepriority[3] = WMI_DATA_BE_SVC;
|
|
servicepriority[4] = WMI_DATA_BK_SVC; /* lowest */
|
|
|
|
/* set callbacks and priority list */
|
|
HTCSetCreditDistribution(HTCHandle,
|
|
pCredInfo,
|
|
ar6000_credit_distribute,
|
|
ar6000_credit_init,
|
|
servicepriority,
|
|
5);
|
|
|
|
return A_OK;
|
|
}
|
|
|