NetBSD/sys/dev/raidframe/rf_dagfuncs.c

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/* $NetBSD: rf_dagfuncs.c,v 1.4 1999/03/14 21:53:31 oster Exp $ */
/*
* Copyright (c) 1995 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Mark Holland, William V. Courtright II
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* dagfuncs.c -- DAG node execution routines
*
* Rules:
* 1. Every DAG execution function must eventually cause node->status to
* get set to "good" or "bad", and "FinishNode" to be called. In the
* case of nodes that complete immediately (xor, NullNodeFunc, etc),
* the node execution function can do these two things directly. In
* the case of nodes that have to wait for some event (a disk read to
* complete, a lock to be released, etc) to occur before they can
* complete, this is typically achieved by having whatever module
* is doing the operation call GenericWakeupFunc upon completion.
* 2. DAG execution functions should check the status in the DAG header
* and NOP out their operations if the status is not "enable". However,
* execution functions that release resources must be sure to release
* them even when they NOP out the function that would use them.
* Functions that acquire resources should go ahead and acquire them
* even when they NOP, so that a downstream release node will not have
* to check to find out whether or not the acquire was suppressed.
*/
#include <sys/ioctl.h>
#include <sys/param.h>
#include "rf_archs.h"
#include "rf_raid.h"
#include "rf_dag.h"
#include "rf_layout.h"
#include "rf_etimer.h"
#include "rf_acctrace.h"
#include "rf_diskqueue.h"
#include "rf_dagfuncs.h"
#include "rf_general.h"
#include "rf_engine.h"
#include "rf_dagutils.h"
#include "rf_kintf.h"
#if RF_INCLUDE_PARITYLOGGING > 0
#include "rf_paritylog.h"
#endif /* RF_INCLUDE_PARITYLOGGING > 0 */
int (*rf_DiskReadFunc) (RF_DagNode_t *);
int (*rf_DiskWriteFunc) (RF_DagNode_t *);
int (*rf_DiskReadUndoFunc) (RF_DagNode_t *);
int (*rf_DiskWriteUndoFunc) (RF_DagNode_t *);
int (*rf_DiskUnlockFunc) (RF_DagNode_t *);
int (*rf_DiskUnlockUndoFunc) (RF_DagNode_t *);
int (*rf_RegularXorUndoFunc) (RF_DagNode_t *);
int (*rf_SimpleXorUndoFunc) (RF_DagNode_t *);
int (*rf_RecoveryXorUndoFunc) (RF_DagNode_t *);
/*****************************************************************************************
* main (only) configuration routine for this module
****************************************************************************************/
int
rf_ConfigureDAGFuncs(listp)
RF_ShutdownList_t **listp;
{
RF_ASSERT(((sizeof(long) == 8) && RF_LONGSHIFT == 3) || ((sizeof(long) == 4) && RF_LONGSHIFT == 2));
rf_DiskReadFunc = rf_DiskReadFuncForThreads;
rf_DiskReadUndoFunc = rf_DiskUndoFunc;
rf_DiskWriteFunc = rf_DiskWriteFuncForThreads;
rf_DiskWriteUndoFunc = rf_DiskUndoFunc;
rf_DiskUnlockFunc = rf_DiskUnlockFuncForThreads;
rf_DiskUnlockUndoFunc = rf_NullNodeUndoFunc;
rf_RegularXorUndoFunc = rf_NullNodeUndoFunc;
rf_SimpleXorUndoFunc = rf_NullNodeUndoFunc;
rf_RecoveryXorUndoFunc = rf_NullNodeUndoFunc;
return (0);
}
/*****************************************************************************************
* the execution function associated with a terminate node
****************************************************************************************/
int
rf_TerminateFunc(node)
RF_DagNode_t *node;
{
RF_ASSERT(node->dagHdr->numCommits == node->dagHdr->numCommitNodes);
node->status = rf_good;
return (rf_FinishNode(node, RF_THREAD_CONTEXT));
}
int
rf_TerminateUndoFunc(node)
RF_DagNode_t *node;
{
return (0);
}
/*****************************************************************************************
* execution functions associated with a mirror node
*
* parameters:
*
* 0 - physical disk addres of data
* 1 - buffer for holding read data
* 2 - parity stripe ID
* 3 - flags
* 4 - physical disk address of mirror (parity)
*
****************************************************************************************/
int
rf_DiskReadMirrorIdleFunc(node)
RF_DagNode_t *node;
{
/* select the mirror copy with the shortest queue and fill in node
* parameters with physical disk address */
rf_SelectMirrorDiskIdle(node);
return (rf_DiskReadFunc(node));
}
int
rf_DiskReadMirrorPartitionFunc(node)
RF_DagNode_t *node;
{
/* select the mirror copy with the shortest queue and fill in node
* parameters with physical disk address */
rf_SelectMirrorDiskPartition(node);
return (rf_DiskReadFunc(node));
}
int
rf_DiskReadMirrorUndoFunc(node)
RF_DagNode_t *node;
{
return (0);
}
#if RF_INCLUDE_PARITYLOGGING > 0
/*****************************************************************************************
* the execution function associated with a parity log update node
****************************************************************************************/
int
rf_ParityLogUpdateFunc(node)
RF_DagNode_t *node;
{
RF_PhysDiskAddr_t *pda = (RF_PhysDiskAddr_t *) node->params[0].p;
caddr_t buf = (caddr_t) node->params[1].p;
RF_ParityLogData_t *logData;
RF_AccTraceEntry_t *tracerec = node->dagHdr->tracerec;
RF_Etimer_t timer;
if (node->dagHdr->status == rf_enable) {
RF_ETIMER_START(timer);
logData = rf_CreateParityLogData(RF_UPDATE, pda, buf,
(RF_Raid_t *) (node->dagHdr->raidPtr),
node->wakeFunc, (void *) node,
node->dagHdr->tracerec, timer);
if (logData)
rf_ParityLogAppend(logData, RF_FALSE, NULL, RF_FALSE);
else {
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->plog_us += RF_ETIMER_VAL_US(timer);
(node->wakeFunc) (node, ENOMEM);
}
}
return (0);
}
/*****************************************************************************************
* the execution function associated with a parity log overwrite node
****************************************************************************************/
int
rf_ParityLogOverwriteFunc(node)
RF_DagNode_t *node;
{
RF_PhysDiskAddr_t *pda = (RF_PhysDiskAddr_t *) node->params[0].p;
caddr_t buf = (caddr_t) node->params[1].p;
RF_ParityLogData_t *logData;
RF_AccTraceEntry_t *tracerec = node->dagHdr->tracerec;
RF_Etimer_t timer;
if (node->dagHdr->status == rf_enable) {
RF_ETIMER_START(timer);
logData = rf_CreateParityLogData(RF_OVERWRITE, pda, buf, (RF_Raid_t *) (node->dagHdr->raidPtr),
node->wakeFunc, (void *) node, node->dagHdr->tracerec, timer);
if (logData)
rf_ParityLogAppend(logData, RF_FALSE, NULL, RF_FALSE);
else {
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->plog_us += RF_ETIMER_VAL_US(timer);
(node->wakeFunc) (node, ENOMEM);
}
}
return (0);
}
#else /* RF_INCLUDE_PARITYLOGGING > 0 */
int
rf_ParityLogUpdateFunc(node)
RF_DagNode_t *node;
{
return (0);
}
int
rf_ParityLogOverwriteFunc(node)
RF_DagNode_t *node;
{
return (0);
}
#endif /* RF_INCLUDE_PARITYLOGGING > 0 */
int
rf_ParityLogUpdateUndoFunc(node)
RF_DagNode_t *node;
{
return (0);
}
int
rf_ParityLogOverwriteUndoFunc(node)
RF_DagNode_t *node;
{
return (0);
}
/*****************************************************************************************
* the execution function associated with a NOP node
****************************************************************************************/
int
rf_NullNodeFunc(node)
RF_DagNode_t *node;
{
node->status = rf_good;
return (rf_FinishNode(node, RF_THREAD_CONTEXT));
}
int
rf_NullNodeUndoFunc(node)
RF_DagNode_t *node;
{
node->status = rf_undone;
return (rf_FinishNode(node, RF_THREAD_CONTEXT));
}
/*****************************************************************************************
* the execution function associated with a disk-read node
****************************************************************************************/
int
rf_DiskReadFuncForThreads(node)
RF_DagNode_t *node;
{
RF_DiskQueueData_t *req;
RF_PhysDiskAddr_t *pda = (RF_PhysDiskAddr_t *) node->params[0].p;
caddr_t buf = (caddr_t) node->params[1].p;
RF_StripeNum_t parityStripeID = (RF_StripeNum_t) node->params[2].v;
unsigned priority = RF_EXTRACT_PRIORITY(node->params[3].v);
unsigned lock = RF_EXTRACT_LOCK_FLAG(node->params[3].v);
unsigned unlock = RF_EXTRACT_UNLOCK_FLAG(node->params[3].v);
unsigned which_ru = RF_EXTRACT_RU(node->params[3].v);
RF_DiskQueueDataFlags_t flags = 0;
RF_IoType_t iotype = (node->dagHdr->status == rf_enable) ? RF_IO_TYPE_READ : RF_IO_TYPE_NOP;
RF_DiskQueue_t **dqs = ((RF_Raid_t *) (node->dagHdr->raidPtr))->Queues;
void *b_proc = NULL;
#if RF_BACKWARD > 0
caddr_t undoBuf;
#endif
if (node->dagHdr->bp)
b_proc = (void *) ((struct buf *) node->dagHdr->bp)->b_proc;
RF_ASSERT(!(lock && unlock));
flags |= (lock) ? RF_LOCK_DISK_QUEUE : 0;
flags |= (unlock) ? RF_UNLOCK_DISK_QUEUE : 0;
#if RF_BACKWARD > 0
/* allocate and zero the undo buffer. this is equivalent to copying
* the original buffer's contents to the undo buffer prior to
* performing the disk read. XXX hardcoded 512 bytes per sector! */
if (node->dagHdr->allocList == NULL)
rf_MakeAllocList(node->dagHdr->allocList);
RF_CallocAndAdd(undoBuf, 1, 512 * pda->numSector, (caddr_t), node->dagHdr->allocList);
#endif /* RF_BACKWARD > 0 */
req = rf_CreateDiskQueueData(iotype, pda->startSector, pda->numSector,
buf, parityStripeID, which_ru,
(int (*) (void *, int)) node->wakeFunc,
node, NULL, node->dagHdr->tracerec,
(void *) (node->dagHdr->raidPtr), flags, b_proc);
if (!req) {
(node->wakeFunc) (node, ENOMEM);
} else {
node->dagFuncData = (void *) req;
rf_DiskIOEnqueue(&(dqs[pda->row][pda->col]), req, priority);
}
return (0);
}
/*****************************************************************************************
* the execution function associated with a disk-write node
****************************************************************************************/
int
rf_DiskWriteFuncForThreads(node)
RF_DagNode_t *node;
{
RF_DiskQueueData_t *req;
RF_PhysDiskAddr_t *pda = (RF_PhysDiskAddr_t *) node->params[0].p;
caddr_t buf = (caddr_t) node->params[1].p;
RF_StripeNum_t parityStripeID = (RF_StripeNum_t) node->params[2].v;
unsigned priority = RF_EXTRACT_PRIORITY(node->params[3].v);
unsigned lock = RF_EXTRACT_LOCK_FLAG(node->params[3].v);
unsigned unlock = RF_EXTRACT_UNLOCK_FLAG(node->params[3].v);
unsigned which_ru = RF_EXTRACT_RU(node->params[3].v);
RF_DiskQueueDataFlags_t flags = 0;
RF_IoType_t iotype = (node->dagHdr->status == rf_enable) ? RF_IO_TYPE_WRITE : RF_IO_TYPE_NOP;
RF_DiskQueue_t **dqs = ((RF_Raid_t *) (node->dagHdr->raidPtr))->Queues;
void *b_proc = NULL;
#if RF_BACKWARD > 0
caddr_t undoBuf;
#endif
if (node->dagHdr->bp)
b_proc = (void *) ((struct buf *) node->dagHdr->bp)->b_proc;
#if RF_BACKWARD > 0
/* This area is used only for backward error recovery experiments
* First, schedule allocate a buffer and schedule a pre-read of the
* disk After the pre-read, proceed with the normal disk write */
if (node->status == rf_bwd2) {
/* just finished undo logging, now perform real function */
node->status = rf_fired;
RF_ASSERT(!(lock && unlock));
flags |= (lock) ? RF_LOCK_DISK_QUEUE : 0;
flags |= (unlock) ? RF_UNLOCK_DISK_QUEUE : 0;
req = rf_CreateDiskQueueData(iotype,
pda->startSector, pda->numSector, buf, parityStripeID, which_ru,
node->wakeFunc, (void *) node, NULL, node->dagHdr->tracerec,
(void *) (node->dagHdr->raidPtr), flags, b_proc);
if (!req) {
(node->wakeFunc) (node, ENOMEM);
} else {
node->dagFuncData = (void *) req;
rf_DiskIOEnqueue(&(dqs[pda->row][pda->col]), req, priority);
}
} else {
/* node status should be rf_fired */
/* schedule a disk pre-read */
node->status = rf_bwd1;
RF_ASSERT(!(lock && unlock));
flags |= (lock) ? RF_LOCK_DISK_QUEUE : 0;
flags |= (unlock) ? RF_UNLOCK_DISK_QUEUE : 0;
if (node->dagHdr->allocList == NULL)
rf_MakeAllocList(node->dagHdr->allocList);
RF_CallocAndAdd(undoBuf, 1, 512 * pda->numSector, (caddr_t), node->dagHdr->allocList);
req = rf_CreateDiskQueueData(RF_IO_TYPE_READ,
pda->startSector, pda->numSector, undoBuf, parityStripeID, which_ru,
node->wakeFunc, (void *) node, NULL, node->dagHdr->tracerec,
(void *) (node->dagHdr->raidPtr), flags, b_proc);
if (!req) {
(node->wakeFunc) (node, ENOMEM);
} else {
node->dagFuncData = (void *) req;
rf_DiskIOEnqueue(&(dqs[pda->row][pda->col]), req, priority);
}
}
return (0);
#endif /* RF_BACKWARD > 0 */
/* normal processing (rollaway or forward recovery) begins here */
RF_ASSERT(!(lock && unlock));
flags |= (lock) ? RF_LOCK_DISK_QUEUE : 0;
flags |= (unlock) ? RF_UNLOCK_DISK_QUEUE : 0;
req = rf_CreateDiskQueueData(iotype, pda->startSector, pda->numSector,
buf, parityStripeID, which_ru,
(int (*) (void *, int)) node->wakeFunc,
(void *) node, NULL,
node->dagHdr->tracerec,
(void *) (node->dagHdr->raidPtr),
flags, b_proc);
if (!req) {
(node->wakeFunc) (node, ENOMEM);
} else {
node->dagFuncData = (void *) req;
rf_DiskIOEnqueue(&(dqs[pda->row][pda->col]), req, priority);
}
return (0);
}
/*****************************************************************************************
* the undo function for disk nodes
* Note: this is not a proper undo of a write node, only locks are released.
* old data is not restored to disk!
****************************************************************************************/
int
rf_DiskUndoFunc(node)
RF_DagNode_t *node;
{
RF_DiskQueueData_t *req;
RF_PhysDiskAddr_t *pda = (RF_PhysDiskAddr_t *) node->params[0].p;
RF_DiskQueue_t **dqs = ((RF_Raid_t *) (node->dagHdr->raidPtr))->Queues;
req = rf_CreateDiskQueueData(RF_IO_TYPE_NOP,
0L, 0, NULL, 0L, 0,
(int (*) (void *, int)) node->wakeFunc,
(void *) node,
NULL, node->dagHdr->tracerec,
(void *) (node->dagHdr->raidPtr),
RF_UNLOCK_DISK_QUEUE, NULL);
if (!req)
(node->wakeFunc) (node, ENOMEM);
else {
node->dagFuncData = (void *) req;
rf_DiskIOEnqueue(&(dqs[pda->row][pda->col]), req, RF_IO_NORMAL_PRIORITY);
}
return (0);
}
/*****************************************************************************************
* the execution function associated with an "unlock disk queue" node
****************************************************************************************/
int
rf_DiskUnlockFuncForThreads(node)
RF_DagNode_t *node;
{
RF_DiskQueueData_t *req;
RF_PhysDiskAddr_t *pda = (RF_PhysDiskAddr_t *) node->params[0].p;
RF_DiskQueue_t **dqs = ((RF_Raid_t *) (node->dagHdr->raidPtr))->Queues;
req = rf_CreateDiskQueueData(RF_IO_TYPE_NOP,
0L, 0, NULL, 0L, 0,
(int (*) (void *, int)) node->wakeFunc,
(void *) node,
NULL, node->dagHdr->tracerec,
(void *) (node->dagHdr->raidPtr),
RF_UNLOCK_DISK_QUEUE, NULL);
if (!req)
(node->wakeFunc) (node, ENOMEM);
else {
node->dagFuncData = (void *) req;
rf_DiskIOEnqueue(&(dqs[pda->row][pda->col]), req, RF_IO_NORMAL_PRIORITY);
}
return (0);
}
/*****************************************************************************************
* Callback routine for DiskRead and DiskWrite nodes. When the disk op completes,
* the routine is called to set the node status and inform the execution engine that
* the node has fired.
****************************************************************************************/
int
rf_GenericWakeupFunc(node, status)
RF_DagNode_t *node;
int status;
{
switch (node->status) {
case rf_bwd1:
node->status = rf_bwd2;
if (node->dagFuncData)
rf_FreeDiskQueueData((RF_DiskQueueData_t *) node->dagFuncData);
return (rf_DiskWriteFuncForThreads(node));
break;
case rf_fired:
if (status)
node->status = rf_bad;
else
node->status = rf_good;
break;
case rf_recover:
/* probably should never reach this case */
if (status)
node->status = rf_panic;
else
node->status = rf_undone;
break;
default:
printf("rf_GenericWakeupFunc:");
printf("node->status is %d,", node->status);
printf("status is %d \n", status);
RF_PANIC();
break;
}
if (node->dagFuncData)
rf_FreeDiskQueueData((RF_DiskQueueData_t *) node->dagFuncData);
return (rf_FinishNode(node, RF_INTR_CONTEXT));
}
/*****************************************************************************************
* there are three distinct types of xor nodes
* A "regular xor" is used in the fault-free case where the access spans a complete
* stripe unit. It assumes that the result buffer is one full stripe unit in size,
* and uses the stripe-unit-offset values that it computes from the PDAs to determine
* where within the stripe unit to XOR each argument buffer.
*
* A "simple xor" is used in the fault-free case where the access touches only a portion
* of one (or two, in some cases) stripe unit(s). It assumes that all the argument
* buffers are of the same size and have the same stripe unit offset.
*
* A "recovery xor" is used in the degraded-mode case. It's similar to the regular
* xor function except that it takes the failed PDA as an additional parameter, and
* uses it to determine what portions of the argument buffers need to be xor'd into
* the result buffer, and where in the result buffer they should go.
****************************************************************************************/
/* xor the params together and store the result in the result field.
* assume the result field points to a buffer that is the size of one SU,
* and use the pda params to determine where within the buffer to XOR
* the input buffers.
*/
int
rf_RegularXorFunc(node)
RF_DagNode_t *node;
{
RF_Raid_t *raidPtr = (RF_Raid_t *) node->params[node->numParams - 1].p;
RF_AccTraceEntry_t *tracerec = node->dagHdr->tracerec;
RF_Etimer_t timer;
int i, retcode;
#if RF_BACKWARD > 0
RF_PhysDiskAddr_t *pda;
caddr_t undoBuf;
#endif
retcode = 0;
if (node->dagHdr->status == rf_enable) {
/* don't do the XOR if the input is the same as the output */
RF_ETIMER_START(timer);
for (i = 0; i < node->numParams - 1; i += 2)
if (node->params[i + 1].p != node->results[0]) {
#if RF_BACKWARD > 0
/* This section mimics undo logging for
* backward error recovery experiments b
* allocating and initializing a buffer XXX
* 512 byte sector size is hard coded! */
pda = node->params[i].p;
if (node->dagHdr->allocList == NULL)
rf_MakeAllocList(node->dagHdr->allocList);
RF_CallocAndAdd(undoBuf, 1, 512 * pda->numSector, (caddr_t), node->dagHdr->allocList);
#endif /* RF_BACKWARD > 0 */
retcode = rf_XorIntoBuffer(raidPtr, (RF_PhysDiskAddr_t *) node->params[i].p,
(char *) node->params[i + 1].p, (char *) node->results[0], node->dagHdr->bp);
}
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->xor_us += RF_ETIMER_VAL_US(timer);
}
return (rf_GenericWakeupFunc(node, retcode)); /* call wake func
* explicitly since no
* I/O in this node */
}
/* xor the inputs into the result buffer, ignoring placement issues */
int
rf_SimpleXorFunc(node)
RF_DagNode_t *node;
{
RF_Raid_t *raidPtr = (RF_Raid_t *) node->params[node->numParams - 1].p;
int i, retcode = 0;
RF_AccTraceEntry_t *tracerec = node->dagHdr->tracerec;
RF_Etimer_t timer;
#if RF_BACKWARD > 0
RF_PhysDiskAddr_t *pda;
caddr_t undoBuf;
#endif
if (node->dagHdr->status == rf_enable) {
RF_ETIMER_START(timer);
/* don't do the XOR if the input is the same as the output */
for (i = 0; i < node->numParams - 1; i += 2)
if (node->params[i + 1].p != node->results[0]) {
#if RF_BACKWARD > 0
/* This section mimics undo logging for
* backward error recovery experiments b
* allocating and initializing a buffer XXX
* 512 byte sector size is hard coded! */
pda = node->params[i].p;
if (node->dagHdr->allocList == NULL)
rf_MakeAllocList(node->dagHdr->allocList);
RF_CallocAndAdd(undoBuf, 1, 512 * pda->numSector, (caddr_t), node->dagHdr->allocList);
#endif /* RF_BACKWARD > 0 */
retcode = rf_bxor((char *) node->params[i + 1].p, (char *) node->results[0],
rf_RaidAddressToByte(raidPtr, ((RF_PhysDiskAddr_t *) node->params[i].p)->numSector),
(struct buf *) node->dagHdr->bp);
}
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->xor_us += RF_ETIMER_VAL_US(timer);
}
return (rf_GenericWakeupFunc(node, retcode)); /* call wake func
* explicitly since no
* I/O in this node */
}
/* this xor is used by the degraded-mode dag functions to recover lost data.
* the second-to-last parameter is the PDA for the failed portion of the access.
* the code here looks at this PDA and assumes that the xor target buffer is
* equal in size to the number of sectors in the failed PDA. It then uses
* the other PDAs in the parameter list to determine where within the target
* buffer the corresponding data should be xored.
*/
int
rf_RecoveryXorFunc(node)
RF_DagNode_t *node;
{
RF_Raid_t *raidPtr = (RF_Raid_t *) node->params[node->numParams - 1].p;
RF_RaidLayout_t *layoutPtr = (RF_RaidLayout_t *) & raidPtr->Layout;
RF_PhysDiskAddr_t *failedPDA = (RF_PhysDiskAddr_t *) node->params[node->numParams - 2].p;
int i, retcode = 0;
RF_PhysDiskAddr_t *pda;
int suoffset, failedSUOffset = rf_StripeUnitOffset(layoutPtr, failedPDA->startSector);
char *srcbuf, *destbuf;
RF_AccTraceEntry_t *tracerec = node->dagHdr->tracerec;
RF_Etimer_t timer;
#if RF_BACKWARD > 0
caddr_t undoBuf;
#endif
if (node->dagHdr->status == rf_enable) {
RF_ETIMER_START(timer);
for (i = 0; i < node->numParams - 2; i += 2)
if (node->params[i + 1].p != node->results[0]) {
pda = (RF_PhysDiskAddr_t *) node->params[i].p;
#if RF_BACKWARD > 0
/* This section mimics undo logging for
* backward error recovery experiments b
* allocating and initializing a buffer XXX
* 512 byte sector size is hard coded! */
if (node->dagHdr->allocList == NULL)
rf_MakeAllocList(node->dagHdr->allocList);
RF_CallocAndAdd(undoBuf, 1, 512 * pda->numSector, (caddr_t), node->dagHdr->allocList);
#endif /* RF_BACKWARD > 0 */
srcbuf = (char *) node->params[i + 1].p;
suoffset = rf_StripeUnitOffset(layoutPtr, pda->startSector);
destbuf = ((char *) node->results[0]) + rf_RaidAddressToByte(raidPtr, suoffset - failedSUOffset);
retcode = rf_bxor(srcbuf, destbuf, rf_RaidAddressToByte(raidPtr, pda->numSector), node->dagHdr->bp);
}
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->xor_us += RF_ETIMER_VAL_US(timer);
}
return (rf_GenericWakeupFunc(node, retcode));
}
/*****************************************************************************************
* The next three functions are utilities used by the above xor-execution functions.
****************************************************************************************/
/*
* this is just a glorified buffer xor. targbuf points to a buffer that is one full stripe unit
* in size. srcbuf points to a buffer that may be less than 1 SU, but never more. When the
* access described by pda is one SU in size (which by implication means it's SU-aligned),
* all that happens is (targbuf) <- (srcbuf ^ targbuf). When the access is less than one
* SU in size the XOR occurs on only the portion of targbuf identified in the pda.
*/
int
rf_XorIntoBuffer(raidPtr, pda, srcbuf, targbuf, bp)
RF_Raid_t *raidPtr;
RF_PhysDiskAddr_t *pda;
char *srcbuf;
char *targbuf;
void *bp;
{
char *targptr;
int sectPerSU = raidPtr->Layout.sectorsPerStripeUnit;
int SUOffset = pda->startSector % sectPerSU;
int length, retcode = 0;
RF_ASSERT(pda->numSector <= sectPerSU);
targptr = targbuf + rf_RaidAddressToByte(raidPtr, SUOffset);
length = rf_RaidAddressToByte(raidPtr, pda->numSector);
retcode = rf_bxor(srcbuf, targptr, length, bp);
return (retcode);
}
/* it really should be the case that the buffer pointers (returned by malloc)
* are aligned to the natural word size of the machine, so this is the only
* case we optimize for. The length should always be a multiple of the sector
* size, so there should be no problem with leftover bytes at the end.
*/
int
rf_bxor(src, dest, len, bp)
char *src;
char *dest;
int len;
void *bp;
{
unsigned mask = sizeof(long) - 1, retcode = 0;
if (!(((unsigned long) src) & mask) && !(((unsigned long) dest) & mask) && !(len & mask)) {
retcode = rf_longword_bxor((unsigned long *) src, (unsigned long *) dest, len >> RF_LONGSHIFT, bp);
} else {
RF_ASSERT(0);
}
return (retcode);
}
/* map a user buffer into kernel space, if necessary */
#define REMAP_VA(_bp,x,y) (y) = (x)
/* When XORing in kernel mode, we need to map each user page to kernel space before we can access it.
* We don't want to assume anything about which input buffers are in kernel/user
* space, nor about their alignment, so in each loop we compute the maximum number
* of bytes that we can xor without crossing any page boundaries, and do only this many
* bytes before the next remap.
*/
int
rf_longword_bxor(src, dest, len, bp)
register unsigned long *src;
register unsigned long *dest;
int len; /* longwords */
void *bp;
{
register unsigned long *end = src + len;
register unsigned long d0, d1, d2, d3, s0, s1, s2, s3; /* temps */
register unsigned long *pg_src, *pg_dest; /* per-page source/dest
* pointers */
int longs_this_time;/* # longwords to xor in the current iteration */
REMAP_VA(bp, src, pg_src);
REMAP_VA(bp, dest, pg_dest);
if (!pg_src || !pg_dest)
return (EFAULT);
while (len >= 4) {
longs_this_time = RF_MIN(len, RF_MIN(RF_BLIP(pg_src), RF_BLIP(pg_dest)) >> RF_LONGSHIFT); /* note len in longwords */
src += longs_this_time;
dest += longs_this_time;
len -= longs_this_time;
while (longs_this_time >= 4) {
d0 = pg_dest[0];
d1 = pg_dest[1];
d2 = pg_dest[2];
d3 = pg_dest[3];
s0 = pg_src[0];
s1 = pg_src[1];
s2 = pg_src[2];
s3 = pg_src[3];
pg_dest[0] = d0 ^ s0;
pg_dest[1] = d1 ^ s1;
pg_dest[2] = d2 ^ s2;
pg_dest[3] = d3 ^ s3;
pg_src += 4;
pg_dest += 4;
longs_this_time -= 4;
}
while (longs_this_time > 0) { /* cannot cross any page
* boundaries here */
*pg_dest++ ^= *pg_src++;
longs_this_time--;
}
/* either we're done, or we've reached a page boundary on one
* (or possibly both) of the pointers */
if (len) {
if (RF_PAGE_ALIGNED(src))
REMAP_VA(bp, src, pg_src);
if (RF_PAGE_ALIGNED(dest))
REMAP_VA(bp, dest, pg_dest);
if (!pg_src || !pg_dest)
return (EFAULT);
}
}
while (src < end) {
*pg_dest++ ^= *pg_src++;
src++;
dest++;
len--;
if (RF_PAGE_ALIGNED(src))
REMAP_VA(bp, src, pg_src);
if (RF_PAGE_ALIGNED(dest))
REMAP_VA(bp, dest, pg_dest);
}
RF_ASSERT(len == 0);
return (0);
}
/*
dst = a ^ b ^ c;
a may equal dst
see comment above longword_bxor
*/
int
rf_longword_bxor3(dst, a, b, c, len, bp)
register unsigned long *dst;
register unsigned long *a;
register unsigned long *b;
register unsigned long *c;
int len; /* length in longwords */
void *bp;
{
unsigned long a0, a1, a2, a3, b0, b1, b2, b3;
register unsigned long *pg_a, *pg_b, *pg_c, *pg_dst; /* per-page source/dest
* pointers */
int longs_this_time;/* # longs to xor in the current iteration */
char dst_is_a = 0;
REMAP_VA(bp, a, pg_a);
REMAP_VA(bp, b, pg_b);
REMAP_VA(bp, c, pg_c);
if (a == dst) {
pg_dst = pg_a;
dst_is_a = 1;
} else {
REMAP_VA(bp, dst, pg_dst);
}
/* align dest to cache line. Can't cross a pg boundary on dst here. */
while ((((unsigned long) pg_dst) & 0x1f)) {
*pg_dst++ = *pg_a++ ^ *pg_b++ ^ *pg_c++;
dst++;
a++;
b++;
c++;
if (RF_PAGE_ALIGNED(a)) {
REMAP_VA(bp, a, pg_a);
if (!pg_a)
return (EFAULT);
}
if (RF_PAGE_ALIGNED(b)) {
REMAP_VA(bp, a, pg_b);
if (!pg_b)
return (EFAULT);
}
if (RF_PAGE_ALIGNED(c)) {
REMAP_VA(bp, a, pg_c);
if (!pg_c)
return (EFAULT);
}
len--;
}
while (len > 4) {
longs_this_time = RF_MIN(len, RF_MIN(RF_BLIP(a), RF_MIN(RF_BLIP(b), RF_MIN(RF_BLIP(c), RF_BLIP(dst)))) >> RF_LONGSHIFT);
a += longs_this_time;
b += longs_this_time;
c += longs_this_time;
dst += longs_this_time;
len -= longs_this_time;
while (longs_this_time >= 4) {
a0 = pg_a[0];
longs_this_time -= 4;
a1 = pg_a[1];
a2 = pg_a[2];
a3 = pg_a[3];
pg_a += 4;
b0 = pg_b[0];
b1 = pg_b[1];
b2 = pg_b[2];
b3 = pg_b[3];
/* start dual issue */
a0 ^= b0;
b0 = pg_c[0];
pg_b += 4;
a1 ^= b1;
a2 ^= b2;
a3 ^= b3;
b1 = pg_c[1];
a0 ^= b0;
b2 = pg_c[2];
a1 ^= b1;
b3 = pg_c[3];
a2 ^= b2;
pg_dst[0] = a0;
a3 ^= b3;
pg_dst[1] = a1;
pg_c += 4;
pg_dst[2] = a2;
pg_dst[3] = a3;
pg_dst += 4;
}
while (longs_this_time > 0) { /* cannot cross any page
* boundaries here */
*pg_dst++ = *pg_a++ ^ *pg_b++ ^ *pg_c++;
longs_this_time--;
}
if (len) {
if (RF_PAGE_ALIGNED(a)) {
REMAP_VA(bp, a, pg_a);
if (!pg_a)
return (EFAULT);
if (dst_is_a)
pg_dst = pg_a;
}
if (RF_PAGE_ALIGNED(b)) {
REMAP_VA(bp, b, pg_b);
if (!pg_b)
return (EFAULT);
}
if (RF_PAGE_ALIGNED(c)) {
REMAP_VA(bp, c, pg_c);
if (!pg_c)
return (EFAULT);
}
if (!dst_is_a)
if (RF_PAGE_ALIGNED(dst)) {
REMAP_VA(bp, dst, pg_dst);
if (!pg_dst)
return (EFAULT);
}
}
}
while (len) {
*pg_dst++ = *pg_a++ ^ *pg_b++ ^ *pg_c++;
dst++;
a++;
b++;
c++;
if (RF_PAGE_ALIGNED(a)) {
REMAP_VA(bp, a, pg_a);
if (!pg_a)
return (EFAULT);
if (dst_is_a)
pg_dst = pg_a;
}
if (RF_PAGE_ALIGNED(b)) {
REMAP_VA(bp, b, pg_b);
if (!pg_b)
return (EFAULT);
}
if (RF_PAGE_ALIGNED(c)) {
REMAP_VA(bp, c, pg_c);
if (!pg_c)
return (EFAULT);
}
if (!dst_is_a)
if (RF_PAGE_ALIGNED(dst)) {
REMAP_VA(bp, dst, pg_dst);
if (!pg_dst)
return (EFAULT);
}
len--;
}
return (0);
}
int
rf_bxor3(dst, a, b, c, len, bp)
register unsigned char *dst;
register unsigned char *a;
register unsigned char *b;
register unsigned char *c;
unsigned long len;
void *bp;
{
RF_ASSERT(((RF_UL(dst) | RF_UL(a) | RF_UL(b) | RF_UL(c) | len) & 0x7) == 0);
return (rf_longword_bxor3((unsigned long *) dst, (unsigned long *) a,
(unsigned long *) b, (unsigned long *) c, len >> RF_LONGSHIFT, bp));
}