From 4dbd5b751767bf88ffdda5d55646738871c751ad Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Wed, 23 Sep 2009 14:27:26 +0200 Subject: Add ar6000 wireless driver. --- drivers/ar6000/miscdrv/common_drv.c | 467 +++++++++++++++++++++++++++++++++++ drivers/ar6000/miscdrv/credit_dist.c | 346 ++++++++++++++++++++++++++ 2 files changed, 813 insertions(+) create mode 100644 drivers/ar6000/miscdrv/common_drv.c create mode 100644 drivers/ar6000/miscdrv/credit_dist.c (limited to 'drivers/ar6000/miscdrv') diff --git a/drivers/ar6000/miscdrv/common_drv.c b/drivers/ar6000/miscdrv/common_drv.c new file mode 100644 index 00000000000..4f127346665 --- /dev/null +++ b/drivers/ar6000/miscdrv/common_drv.c @@ -0,0 +1,467 @@ + +/* + * + * 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 "AR6Khwreg.h" +#include "targaddrs.h" +#include "a_osapi.h" +#include "hif.h" +#include "htc_api.h" +#include "bmi.h" +#include "bmi_msg.h" +#include "common_drv.h" +#include "a_debug.h" +#include "targaddrs.h" + +#define HOST_INTEREST_ITEM_ADDRESS(target, item) \ +(((TargetType) == TARGET_TYPE_AR6001) ? \ + AR6001_HOST_INTEREST_ITEM_ADDRESS(item) : \ + AR6002_HOST_INTEREST_ITEM_ADDRESS(item)) + + +/* Compile the 4BYTE version of the window register setup routine, + * This mitigates host interconnect issues with non-4byte aligned bus requests, some + * interconnects use bus adapters that impose strict limitations. + * Since diag window access is not intended for performance critical operations, the 4byte mode should + * be satisfactory even though it generates 4X the bus activity. */ + +#ifdef USE_4BYTE_REGISTER_ACCESS + + /* set the window address register (using 4-byte register access ). */ +A_STATUS ar6000_SetAddressWindowRegister(HIF_DEVICE *hifDevice, A_UINT32 RegisterAddr, A_UINT32 Address) +{ + A_STATUS status; + A_UINT8 addrValue[4]; + int i; + + /* write bytes 1,2,3 of the register to set the upper address bytes, the LSB is written + * last to initiate the access cycle */ + + for (i = 1; i <= 3; i++) { + /* fill the buffer with the address byte value we want to hit 4 times*/ + addrValue[0] = ((A_UINT8 *)&Address)[i]; + addrValue[1] = addrValue[0]; + addrValue[2] = addrValue[0]; + addrValue[3] = addrValue[0]; + + /* hit each byte of the register address with a 4-byte write operation to the same address, + * this is a harmless operation */ + status = HIFReadWrite(hifDevice, + RegisterAddr+i, + addrValue, + 4, + HIF_WR_SYNC_BYTE_FIX, + NULL); + if (status != A_OK) { + break; + } + } + + if (status != A_OK) { + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Cannot write initial bytes of 0x%x to window reg: 0x%X \n", + RegisterAddr, Address)); + return status; + } + + /* write the address register again, this time write the whole 4-byte value. + * The effect here is that the LSB write causes the cycle to start, the extra + * 3 byte write to bytes 1,2,3 has no effect since we are writing the same values again */ + status = HIFReadWrite(hifDevice, + RegisterAddr, + (A_UCHAR *)(&Address), + 4, + HIF_WR_SYNC_BYTE_INC, + NULL); + + if (status != A_OK) { + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Cannot write 0x%x to window reg: 0x%X \n", + RegisterAddr, Address)); + return status; + } + + return A_OK; + + + +} + + +#else + + /* set the window address register */ +A_STATUS ar6000_SetAddressWindowRegister(HIF_DEVICE *hifDevice, A_UINT32 RegisterAddr, A_UINT32 Address) +{ + A_STATUS status; + + /* write bytes 1,2,3 of the register to set the upper address bytes, the LSB is written + * last to initiate the access cycle */ + status = HIFReadWrite(hifDevice, + RegisterAddr+1, /* write upper 3 bytes */ + ((A_UCHAR *)(&Address))+1, + sizeof(A_UINT32)-1, + HIF_WR_SYNC_BYTE_INC, + NULL); + + if (status != A_OK) { + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Cannot write initial bytes of 0x%x to window reg: 0x%X \n", + RegisterAddr, Address)); + return status; + } + + /* write the LSB of the register, this initiates the operation */ + status = HIFReadWrite(hifDevice, + RegisterAddr, + (A_UCHAR *)(&Address), + sizeof(A_UINT8), + HIF_WR_SYNC_BYTE_INC, + NULL); + + if (status != A_OK) { + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Cannot write 0x%x to window reg: 0x%X \n", + RegisterAddr, Address)); + return status; + } + + return A_OK; +} + +#endif + +/* + * Read from the AR6000 through its diagnostic window. + * No cooperation from the Target is required for this. + */ +A_STATUS +ar6000_ReadRegDiag(HIF_DEVICE *hifDevice, A_UINT32 *address, A_UINT32 *data) +{ + A_STATUS status; + + /* set window register to start read cycle */ + status = ar6000_SetAddressWindowRegister(hifDevice, + WINDOW_READ_ADDR_ADDRESS, + *address); + + if (status != A_OK) { + return status; + } + + /* read the data */ + status = HIFReadWrite(hifDevice, + WINDOW_DATA_ADDRESS, + (A_UCHAR *)data, + sizeof(A_UINT32), + HIF_RD_SYNC_BYTE_INC, + NULL); + if (status != A_OK) { + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Cannot read from WINDOW_DATA_ADDRESS\n")); + return status; + } + + return status; +} + + +/* + * Write to the AR6000 through its diagnostic window. + * No cooperation from the Target is required for this. + */ +A_STATUS +ar6000_WriteRegDiag(HIF_DEVICE *hifDevice, A_UINT32 *address, A_UINT32 *data) +{ + A_STATUS status; + + /* set write data */ + status = HIFReadWrite(hifDevice, + WINDOW_DATA_ADDRESS, + (A_UCHAR *)data, + sizeof(A_UINT32), + HIF_WR_SYNC_BYTE_INC, + NULL); + if (status != A_OK) { + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Cannot write 0x%x to WINDOW_DATA_ADDRESS\n", *data)); + return status; + } + + /* set window register, which starts the write cycle */ + return ar6000_SetAddressWindowRegister(hifDevice, + WINDOW_WRITE_ADDR_ADDRESS, + *address); +} + +A_STATUS +ar6000_ReadDataDiag(HIF_DEVICE *hifDevice, A_UINT32 address, + A_UCHAR *data, A_UINT32 length) +{ + A_UINT32 count; + A_STATUS status = A_OK; + + for (count = 0; count < length; count += 4, address += 4) { + if ((status = ar6000_ReadRegDiag(hifDevice, &address, + (A_UINT32 *)&data[count])) != A_OK) + { + break; + } + } + + return status; +} + +A_STATUS +ar6000_WriteDataDiag(HIF_DEVICE *hifDevice, A_UINT32 address, + A_UCHAR *data, A_UINT32 length) +{ + A_UINT32 count; + A_STATUS status = A_OK; + + for (count = 0; count < length; count += 4, address += 4) { + if ((status = ar6000_WriteRegDiag(hifDevice, &address, + (A_UINT32 *)&data[count])) != A_OK) + { + break; + } + } + + return status; +} + +A_STATUS +ar6000_reset_device_skipflash(HIF_DEVICE *hifDevice) +{ + int i; + struct forceROM_s { + A_UINT32 addr; + A_UINT32 data; + }; + struct forceROM_s *ForceROM; + int szForceROM; + A_UINT32 instruction; + + static struct forceROM_s ForceROM_REV2[] = { + /* NB: This works for old REV2 ROM (old). */ + {0x00001ff0, 0x175b0027}, /* jump instruction at 0xa0001ff0 */ + {0x00001ff4, 0x00000000}, /* nop instruction at 0xa0001ff4 */ + + {MC_REMAP_TARGET_ADDRESS, 0x00001ff0}, /* remap to 0xa0001ff0 */ + {MC_REMAP_COMPARE_ADDRESS, 0x01000040},/* ...from 0xbfc00040 */ + {MC_REMAP_SIZE_ADDRESS, 0x00000000}, /* ...1 cache line */ + {MC_REMAP_VALID_ADDRESS, 0x00000001}, /* ...remap is valid */ + + {LOCAL_COUNT_ADDRESS+0x10, 0}, /* clear BMI credit counter */ + + {RESET_CONTROL_ADDRESS, RESET_CONTROL_WARM_RST_MASK}, + }; + + static struct forceROM_s ForceROM_NEW[] = { + /* NB: This works for AR6000 ROM REV3 and beyond. */ + {LOCAL_SCRATCH_ADDRESS, AR6K_OPTION_IGNORE_FLASH}, + {LOCAL_COUNT_ADDRESS+0x10, 0}, /* clear BMI credit counter */ + {RESET_CONTROL_ADDRESS, RESET_CONTROL_WARM_RST_MASK}, + }; + + /* + * Examine a semi-arbitrary instruction that's different + * in REV2 and other revisions. + * NB: If a Host port does not require simultaneous support + * for multiple revisions of Target ROM, this code can be elided. + */ + (void)ar6000_ReadDataDiag(hifDevice, 0x01000040, + (A_UCHAR *)&instruction, 4); + + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("instruction=0x%x\n", instruction)); + + if (instruction == 0x3c1aa200) { + /* It's an old ROM */ + ForceROM = ForceROM_REV2; + szForceROM = sizeof(ForceROM_REV2)/sizeof(*ForceROM); + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Using OLD method\n")); + } else { + ForceROM = ForceROM_NEW; + szForceROM = sizeof(ForceROM_NEW)/sizeof(*ForceROM); + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Using NEW method\n")); + } + + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Force Target to execute from ROM....\n")); + for (i = 0; i < szForceROM; i++) + { + if (ar6000_WriteRegDiag(hifDevice, + &ForceROM[i].addr, + &ForceROM[i].data) != A_OK) + { + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Cannot force Target to execute ROM!\n")); + return A_ERROR; + } + } + + msleep(50); /* delay to allow dragon to come to BMI phase */ + return A_OK; +} + +/* reset device */ +A_STATUS ar6000_reset_device(HIF_DEVICE *hifDevice, A_UINT32 TargetType) +{ + +#if !defined(DWSIM) + A_STATUS status = A_OK; + A_UINT32 address; + A_UINT32 data; + + do { + + // address = RESET_CONTROL_ADDRESS; + data = RESET_CONTROL_COLD_RST_MASK; + + /* Hardcode the address of RESET_CONTROL_ADDRESS based on the target type */ + if (TargetType == TARGET_TYPE_AR6001) { + address = 0x0C000000; + } else { + if (TargetType == TARGET_TYPE_AR6002) { + address = 0x00004000; + } else { + A_ASSERT(0); + } + } + + status = ar6000_WriteRegDiag(hifDevice, &address, &data); + + if (A_FAILED(status)) { + break; + } + + /* + * Read back the RESET CAUSE register to ensure that the cold reset + * went through. + */ + msleep(2000); /* 2 second delay to allow things to settle down */ + + + // address = RESET_CAUSE_ADDRESS; + /* Hardcode the address of RESET_CAUSE_ADDRESS based on the target type */ + if (TargetType == TARGET_TYPE_AR6001) { + address = 0x0C0000CC; + } else { + if (TargetType == TARGET_TYPE_AR6002) { + address = 0x000040C0; + } else { + A_ASSERT(0); + } + } + + data = 0; + status = ar6000_ReadRegDiag(hifDevice, &address, &data); + + if (A_FAILED(status)) { + break; + } + + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Reset Cause readback: 0x%X \n",data)); + data &= RESET_CAUSE_LAST_MASK; + if (data != 2) { + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Unable to cold reset the target \n")); + } + + } while (FALSE); + + if (A_FAILED(status)) { + AR_DEBUG_PRINTF(ATH_LOG_ERR, ("Failed to reset target \n")); + } +#endif + return A_OK; +} + +#define REG_DUMP_COUNT_AR6001 38 /* WORDs, derived from AR6001_regdump.h */ +#define REG_DUMP_COUNT_AR6002 32 /* WORDs, derived from AR6002_regdump.h */ + + +#if REG_DUMP_COUNT_AR6001 <= REG_DUMP_COUNT_AR6002 +#define REGISTER_DUMP_LEN_MAX REG_DUMP_COUNT_AR6002 +#else +#define REGISTER_DUMP_LEN_MAX REG_DUMP_COUNT_AR6001 +#endif + +void ar6000_dump_target_assert_info(HIF_DEVICE *hifDevice, A_UINT32 TargetType) +{ + A_UINT32 address; + A_UINT32 regDumpArea = 0; + A_STATUS status; + A_UINT32 regDumpValues[REGISTER_DUMP_LEN_MAX]; + A_UINT32 regDumpCount = 0; + A_UINT32 i; + + do { + + /* the reg dump pointer is copied to the host interest area */ + address = HOST_INTEREST_ITEM_ADDRESS(TargetType, hi_failure_state); + + if (TargetType == TARGET_TYPE_AR6001) { + /* for AR6001, this is a fixed location because the ptr is actually stuck in cache, + * this may be fixed in later firmware versions */ + address = 0x18a0; + regDumpCount = REG_DUMP_COUNT_AR6001; + + } else if (TargetType == TARGET_TYPE_AR6002) { + + regDumpCount = REG_DUMP_COUNT_AR6002; + + } else { + A_ASSERT(0); + } + + /* read RAM location through diagnostic window */ + status = ar6000_ReadRegDiag(hifDevice, &address, ®DumpArea); + + if (A_FAILED(status)) { + AR_DEBUG_PRINTF(ATH_DEBUG_ERR,("AR6K: Failed to get ptr to register dump area \n")); + break; + } + + AR_DEBUG_PRINTF(ATH_DEBUG_ERR,("AR6K: Location of register dump data: 0x%X \n",regDumpArea)); + + if (regDumpArea == 0) { + /* no reg dump */ + break; + } + + if (TargetType == TARGET_TYPE_AR6001) { + regDumpArea &= 0x0FFFFFFF; /* convert to physical address in target memory */ + } + + /* fetch register dump data */ + status = ar6000_ReadDataDiag(hifDevice, + regDumpArea, + (A_UCHAR *)®DumpValues[0], + regDumpCount * (sizeof(A_UINT32))); + + if (A_FAILED(status)) { + AR_DEBUG_PRINTF(ATH_DEBUG_ERR,("AR6K: Failed to get register dump \n")); + break; + } + + AR_DEBUG_PRINTF(ATH_DEBUG_ERR,("AR6K: Register Dump: \n")); + + for (i = 0; i < regDumpCount; i++) { + AR_DEBUG_PRINTF(ATH_DEBUG_ERR,(" %d : 0x%8.8X \n",i, regDumpValues[i])); + } + + } while (FALSE); + +} + diff --git a/drivers/ar6000/miscdrv/credit_dist.c b/drivers/ar6000/miscdrv/credit_dist.c new file mode 100644 index 00000000000..8d37d627203 --- /dev/null +++ b/drivers/ar6000/miscdrv/credit_dist.c @@ -0,0 +1,346 @@ + +/* + * + * 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; +} + -- cgit v1.2.3