/*	$NetBSD: rf_psstatus.c,v 1.34 2011/05/03 08:18:43 mrg Exp $	*/
/*
 * Copyright (c) 1995 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Author: Mark Holland
 *
 * 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.
 */

/*****************************************************************************
 *
 * psstatus.c
 *
 * The reconstruction code maintains a bunch of status related to the parity
 * stripes that are currently under reconstruction.  This header file defines
 * the status structures.
 *
 *****************************************************************************/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rf_psstatus.c,v 1.34 2011/05/03 08:18:43 mrg Exp $");

#include <dev/raidframe/raidframevar.h>

#include "rf_raid.h"
#include "rf_general.h"
#include "rf_debugprint.h"
#include "rf_psstatus.h"
#include "rf_shutdown.h"

#if RF_DEBUG_PSS
#define Dprintf1(s,a)         if (rf_pssDebug) rf_debug_printf(s,(void *)((unsigned long)a),NULL,NULL,NULL,NULL,NULL,NULL,NULL)
#define Dprintf2(s,a,b)       if (rf_pssDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),NULL,NULL,NULL,NULL,NULL,NULL)
#define Dprintf3(s,a,b,c)     if (rf_pssDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),NULL,NULL,NULL,NULL,NULL)
#else
#define Dprintf1(s,a)
#define Dprintf2(s,a,b)
#define Dprintf3(s,a,b,c)
#endif

static void
RealPrintPSStatusTable(RF_Raid_t * raidPtr,
    RF_PSStatusHeader_t * pssTable);

#define RF_MAX_FREE_PSS  32
#define RF_MIN_FREE_PSS   8

static void rf_ShutdownPSStatus(void *);

static void
rf_ShutdownPSStatus(void *arg)
{

	pool_destroy(&rf_pools.pss);
}

int
rf_ConfigurePSStatus(RF_ShutdownList_t **listp)
{

	rf_pool_init(&rf_pools.pss, sizeof(RF_ReconParityStripeStatus_t),
		     "raidpsspl", RF_MIN_FREE_PSS, RF_MAX_FREE_PSS);
	rf_ShutdownCreate(listp, rf_ShutdownPSStatus, NULL);

	return (0);
}

void
rf_InitPSStatus(RF_Raid_t *raidPtr)
{
	raidPtr->pssTableSize = RF_PSS_DEFAULT_TABLESIZE;
}


/*****************************************************************************************
 * sets up the pss table
 * We pre-allocate a bunch of entries to avoid as much as possible having to
 * malloc up hash chain entries.
 ****************************************************************************************/
RF_PSStatusHeader_t *
rf_MakeParityStripeStatusTable(RF_Raid_t *raidPtr)
{
	RF_PSStatusHeader_t *pssTable;
	int     i;

	RF_Malloc(pssTable,
		  raidPtr->pssTableSize * sizeof(RF_PSStatusHeader_t),
		  (RF_PSStatusHeader_t *));
	for (i = 0; i < raidPtr->pssTableSize; i++) {
		rf_init_mutex2(pssTable[i].mutex, IPL_VM);
		rf_init_cond2(pssTable[i].cond, "rfpsslk");
	}
	return (pssTable);
}

void
rf_FreeParityStripeStatusTable(RF_Raid_t *raidPtr,
			       RF_PSStatusHeader_t *pssTable)
{
	int     i;

#if RF_DEBUG_PSS
	if (rf_pssDebug)
		RealPrintPSStatusTable(raidPtr, pssTable);

	for (i = 0; i < raidPtr->pssTableSize; i++) {
		if (pssTable[i].chain) {
			printf("ERROR: pss hash chain not null at recon shutdown\n");
		}
	}
#endif
	for (i = 0; i < raidPtr->pssTableSize; i++) {
		rf_destroy_mutex2(pssTable[i].mutex);
		rf_destroy_cond2(pssTable[i].cond);
	}
	RF_Free(pssTable, raidPtr->pssTableSize * sizeof(RF_PSStatusHeader_t));
}


/* looks up the status structure for a parity stripe.
 * if the create_flag is on, uses (and returns) newpssPtr if
 * a parity status structure doesn't exist
 * otherwise returns NULL if the status structure does not exist
 *
 * ASSUMES THE PSS DESCRIPTOR IS LOCKED UPON ENTRY
 *
 * flags - whether or not to use newpssPtr if the needed PSS
 *         doesn't exist and what flags to set it to initially
 */
RF_ReconParityStripeStatus_t *
rf_LookupRUStatus(RF_Raid_t *raidPtr, RF_PSStatusHeader_t *pssTable,
		  RF_StripeNum_t psID, RF_ReconUnitNum_t which_ru,
		  RF_PSSFlags_t flags, RF_ReconParityStripeStatus_t *newpssPtr)
{
	RF_PSStatusHeader_t *hdr = &pssTable[RF_HASH_PSID(raidPtr, psID)];
	RF_ReconParityStripeStatus_t *p, *pssPtr = hdr->chain;

	for (p = pssPtr; p; p = p->next) {
		if (p->parityStripeID == psID && p->which_ru == which_ru)
			break;
	}

	if (!p && (flags & RF_PSS_CREATE)) {
		p = newpssPtr;
		p->next = hdr->chain;
		hdr->chain = p;

		p->parityStripeID = psID;
		p->which_ru = which_ru;
		p->flags = flags;
		p->rbuf = NULL;
		p->writeRbuf = NULL;
		p->xorBufCount = 0;
		p->blockCount = 0;
		p->procWaitList = NULL;
		p->blockWaitList = NULL;
		p->bufWaitList = NULL;
	} else
		if (p) {	/* we didn't create, but we want to specify
				 * some new status */
			p->flags |= flags;	/* add in whatever flags we're
						 * specifying */
		}
	if (p && (flags & RF_PSS_RECON_BLOCKED)) {
		p->blockCount++;/* if we're asking to block recon, bump the
				 * count */
		Dprintf3("raid%d: Blocked recon on psid %ld.  count now %d\n",
			 raidPtr->raidid, psID, p->blockCount);
	}
	return (p);
}
/* deletes an entry from the parity stripe status table.  typically used
 * when an entry has been allocated solely to block reconstruction, and
 * no recon was requested while recon was blocked.  Assumes the hash
 * chain is ALREADY LOCKED.
 */
void
rf_PSStatusDelete(RF_Raid_t *raidPtr, RF_PSStatusHeader_t *pssTable,
		  RF_ReconParityStripeStatus_t *pssPtr)
{
	RF_PSStatusHeader_t *hdr = &(pssTable[RF_HASH_PSID(raidPtr, pssPtr->parityStripeID)]);
	RF_ReconParityStripeStatus_t *p = hdr->chain, *pt = NULL;

	while (p) {
		if (p == pssPtr) {
			if (pt)
				pt->next = p->next;
			else
				hdr->chain = p->next;
			p->next = NULL;
			rf_FreePSStatus(raidPtr, p);
			return;
		}
		pt = p;
		p = p->next;
	}
	RF_ASSERT(0);		/* we must find it here */
}
/* deletes an entry from the ps status table after reconstruction has completed */
void
rf_RemoveFromActiveReconTable(RF_Raid_t *raidPtr, RF_StripeNum_t psid,
			      RF_ReconUnitNum_t which_ru)
{
	RF_PSStatusHeader_t *hdr = &(raidPtr->reconControl->pssTable[RF_HASH_PSID(raidPtr, psid)]);
	RF_ReconParityStripeStatus_t *p, *pt;
	RF_CallbackDesc_t *cb, *cb1;

	rf_lock_mutex2(hdr->mutex);
	while(hdr->lock) {
		rf_wait_cond2(hdr->cond, hdr->mutex);
	}
	hdr->lock = 1;
	rf_unlock_mutex2(hdr->mutex);
	for (pt = NULL, p = hdr->chain; p; pt = p, p = p->next) {
		if ((p->parityStripeID == psid) && (p->which_ru == which_ru))
			break;
	}
	if (p == NULL) {
		rf_PrintPSStatusTable(raidPtr);
	}
	RF_ASSERT(p);		/* it must be there */

	Dprintf2("PSS: deleting pss for psid %ld ru %d\n", psid, which_ru);

	/* delete this entry from the hash chain */
	if (pt)
		pt->next = p->next;
	else
		hdr->chain = p->next;
	p->next = NULL;

	rf_lock_mutex2(hdr->mutex);
	hdr->lock = 0;
	rf_unlock_mutex2(hdr->mutex);

	/* wakup anyone waiting on the parity stripe ID */
	cb = p->procWaitList;
	p->procWaitList = NULL;
	while (cb) {
		Dprintf1("Waking up access waiting on parity stripe ID %ld\n", p->parityStripeID);
		cb1 = cb->next;
		(cb->callbackFunc) (cb->callbackArg);
		rf_FreeCallbackDesc(cb);
		cb = cb1;
	}

	rf_FreePSStatus(raidPtr, p);
}

RF_ReconParityStripeStatus_t *
rf_AllocPSStatus(RF_Raid_t *raidPtr)
{
	RF_ReconParityStripeStatus_t *p;

	p = pool_get(&rf_pools.pss, PR_WAITOK);
	memset(p, 0, sizeof(RF_ReconParityStripeStatus_t));
	return (p);
}

void
rf_FreePSStatus(RF_Raid_t *raidPtr, RF_ReconParityStripeStatus_t *p)
{
	RF_ASSERT(p->procWaitList == NULL);
	RF_ASSERT(p->blockWaitList == NULL);
	RF_ASSERT(p->bufWaitList == NULL);

	pool_put(&rf_pools.pss, p);
}

static void
RealPrintPSStatusTable(RF_Raid_t *raidPtr, RF_PSStatusHeader_t *pssTable)
{
	int     i, j, procsWaiting, blocksWaiting, bufsWaiting;
	RF_ReconParityStripeStatus_t *p;
	RF_CallbackDesc_t *cb;

	printf("\nParity Stripe Status Table\n");
	for (i = 0; i < raidPtr->pssTableSize; i++) {
		for (p = pssTable[i].chain; p; p = p->next) {
			procsWaiting = blocksWaiting = bufsWaiting = 0;
			for (cb = p->procWaitList; cb; cb = cb->next)
				procsWaiting++;
			for (cb = p->blockWaitList; cb; cb = cb->next)
				blocksWaiting++;
			for (cb = p->bufWaitList; cb; cb = cb->next)
				bufsWaiting++;
			printf("PSID %ld RU %d : blockCount %d %d/%d/%d proc/block/buf waiting, issued ",
			    (long) p->parityStripeID, p->which_ru, p->blockCount, procsWaiting, blocksWaiting, bufsWaiting);
			for (j = 0; j < raidPtr->numCol; j++)
				printf("%c", (p->issued[j]) ? '1' : '0');
			if (!p->flags)
				printf(" flags: (none)");
			else {
				if (p->flags & RF_PSS_UNDER_RECON)
					printf(" under-recon");
				if (p->flags & RF_PSS_FORCED_ON_WRITE)
					printf(" forced-w");
				if (p->flags & RF_PSS_FORCED_ON_READ)
					printf(" forced-r");
				if (p->flags & RF_PSS_RECON_BLOCKED)
					printf(" blocked");
				if (p->flags & RF_PSS_BUFFERWAIT)
					printf(" bufwait");
			}
			printf("\n");
		}
	}
}

void
rf_PrintPSStatusTable(RF_Raid_t *raidPtr)
{
	RF_PSStatusHeader_t *pssTable = raidPtr->reconControl->pssTable;
	RealPrintPSStatusTable(raidPtr, pssTable);
}