--- /dev/null
+/*
+ * Linux MegaRAID driver for SAS based RAID controllers
+ *
+ * Copyright (c) 2009-2011 LSI Corporation.
+ *
+ * This program 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
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * FILE: megaraid_sas_fp.c
+ *
+ * Authors: LSI Corporation
+ * Sumant Patro
+ * Varad Talamacki
+ * Manoj Jose
+ *
+ * Send feedback to: <megaraidlinux@lsi.com>
+ *
+ * Mail to: LSI Corporation, 1621 Barber Lane, Milpitas, CA 95035
+ * ATTN: Linuxraid
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/list.h>
+#include <linux/moduleparam.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/smp_lock.h>
+#include <linux/uio.h>
+#include <linux/uaccess.h>
+#include <linux/fs.h>
+#include <linux/compat.h>
+#include <linux/blkdev.h>
+#include <linux/poll.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+
+#include "megaraid_sas_fusion.h"
+#include <asm/div64.h>
+
+#define ABS_DIFF(a, b) (((a) > (b)) ? ((a) - (b)) : ((b) - (a)))
+#define MR_LD_STATE_OPTIMAL 3
+#define FALSE 0
+#define TRUE 1
+
+/* Prototypes */
+void
+mr_update_load_balance_params(struct MR_FW_RAID_MAP_ALL *map,
+ struct LD_LOAD_BALANCE_INFO *lbInfo);
+
+u32 mega_mod64(u64 dividend, u32 divisor)
+{
+ u64 d;
+ u32 remainder;
+
+ if (!divisor)
+ printk(KERN_ERR "megasas : DIVISOR is zero, in div fn\n");
+ d = dividend;
+ remainder = do_div(d, divisor);
+ return remainder;
+}
+
+/**
+ * @param dividend : Dividend
+ * @param divisor : Divisor
+ *
+ * @return quotient
+ **/
+u64 mega_div64_32(uint64_t dividend, uint32_t divisor)
+{
+ u32 remainder;
+ u64 d;
+
+ if (!divisor)
+ printk(KERN_ERR "megasas : DIVISOR is zero in mod fn\n");
+
+ d = dividend;
+ remainder = do_div(d, divisor);
+
+ return d;
+}
+
+struct MR_LD_RAID *MR_LdRaidGet(u32 ld, struct MR_FW_RAID_MAP_ALL *map)
+{
+ return &map->raidMap.ldSpanMap[ld].ldRaid;
+}
+
+static struct MR_SPAN_BLOCK_INFO *MR_LdSpanInfoGet(u32 ld,
+ struct MR_FW_RAID_MAP_ALL
+ *map)
+{
+ return &map->raidMap.ldSpanMap[ld].spanBlock[0];
+}
+
+static u8 MR_LdDataArmGet(u32 ld, u32 armIdx, struct MR_FW_RAID_MAP_ALL *map)
+{
+ return map->raidMap.ldSpanMap[ld].dataArmMap[armIdx];
+}
+
+static u16 MR_ArPdGet(u32 ar, u32 arm, struct MR_FW_RAID_MAP_ALL *map)
+{
+ return map->raidMap.arMapInfo[ar].pd[arm];
+}
+
+static u16 MR_LdSpanArrayGet(u32 ld, u32 span, struct MR_FW_RAID_MAP_ALL *map)
+{
+ return map->raidMap.ldSpanMap[ld].spanBlock[span].span.arrayRef;
+}
+
+static u16 MR_PdDevHandleGet(u32 pd, struct MR_FW_RAID_MAP_ALL *map)
+{
+ return map->raidMap.devHndlInfo[pd].curDevHdl;
+}
+
+u16 MR_GetLDTgtId(u32 ld, struct MR_FW_RAID_MAP_ALL *map)
+{
+ return map->raidMap.ldSpanMap[ld].ldRaid.targetId;
+}
+
+u16 MR_TargetIdToLdGet(u32 ldTgtId, struct MR_FW_RAID_MAP_ALL *map)
+{
+ return map->raidMap.ldTgtIdToLd[ldTgtId];
+}
+
+static struct MR_LD_SPAN *MR_LdSpanPtrGet(u32 ld, u32 span,
+ struct MR_FW_RAID_MAP_ALL *map)
+{
+ return &map->raidMap.ldSpanMap[ld].spanBlock[span].span;
+}
+
+/*
+ * This function will validate Map info data provided by FW
+ */
+u8 MR_ValidateMapInfo(struct MR_FW_RAID_MAP_ALL *map,
+ struct LD_LOAD_BALANCE_INFO *lbInfo)
+{
+ struct MR_FW_RAID_MAP *pFwRaidMap = &map->raidMap;
+
+ if (pFwRaidMap->totalSize !=
+ (sizeof(struct MR_FW_RAID_MAP) -sizeof(struct MR_LD_SPAN_MAP) +
+ (sizeof(struct MR_LD_SPAN_MAP) *pFwRaidMap->ldCount))) {
+ printk(KERN_ERR "megasas: map info structure size 0x%x is not matching with ld count\n",
+ (unsigned int)((sizeof(struct MR_FW_RAID_MAP) -
+ sizeof(struct MR_LD_SPAN_MAP)) +
+ (sizeof(struct MR_LD_SPAN_MAP) *
+ pFwRaidMap->ldCount)));
+ printk(KERN_ERR "megasas: span map %x, pFwRaidMap->totalSize "
+ ": %x\n", (unsigned int)sizeof(struct MR_LD_SPAN_MAP),
+ pFwRaidMap->totalSize);
+ return 0;
+ }
+
+ mr_update_load_balance_params(map, lbInfo);
+
+ return 1;
+}
+
+u32 MR_GetSpanBlock(u32 ld, u64 row, u64 *span_blk,
+ struct MR_FW_RAID_MAP_ALL *map, int *div_error)
+{
+ struct MR_SPAN_BLOCK_INFO *pSpanBlock = MR_LdSpanInfoGet(ld, map);
+ struct MR_QUAD_ELEMENT *quad;
+ struct MR_LD_RAID *raid = MR_LdRaidGet(ld, map);
+ u32 span, j;
+
+ for (span = 0; span < raid->spanDepth; span++, pSpanBlock++) {
+
+ for (j = 0; j < pSpanBlock->block_span_info.noElements; j++) {
+ quad = &pSpanBlock->block_span_info.quad[j];
+
+ if (quad->diff == 0) {
+ *div_error = 1;
+ return span;
+ }
+ if (quad->logStart <= row && row <= quad->logEnd &&
+ (mega_mod64(row-quad->logStart, quad->diff)) == 0) {
+ if (span_blk != NULL) {
+ u64 blk, debugBlk;
+ blk =
+ mega_div64_32(
+ (row-quad->logStart),
+ quad->diff);
+ debugBlk = blk;
+
+ blk = (blk + quad->offsetInSpan) <<
+ raid->stripeShift;
+ *span_blk = blk;
+ }
+ return span;
+ }
+ }
+ }
+ return span;
+}
+
+/*
+******************************************************************************
+*
+* This routine calculates the arm, span and block for the specified stripe and
+* reference in stripe.
+*
+* Inputs :
+*
+* ld - Logical drive number
+* stripRow - Stripe number
+* stripRef - Reference in stripe
+*
+* Outputs :
+*
+* span - Span number
+* block - Absolute Block number in the physical disk
+*/
+u8 MR_GetPhyParams(u32 ld, u64 stripRow, u16 stripRef, u64 *pdBlock,
+ u16 *pDevHandle, struct RAID_CONTEXT *pRAID_Context,
+ struct MR_FW_RAID_MAP_ALL *map)
+{
+ struct MR_LD_RAID *raid = MR_LdRaidGet(ld, map);
+ u32 pd, arRef;
+ u8 physArm, span;
+ u64 row;
+ u8 retval = TRUE;
+ int error_code = 0;
+
+ row = mega_div64_32(stripRow, raid->rowDataSize);
+
+ if (raid->level == 6) {
+ /* logical arm within row */
+ u32 logArm = mega_mod64(stripRow, raid->rowDataSize);
+ u32 rowMod, armQ, arm;
+
+ if (raid->rowSize == 0)
+ return FALSE;
+ /* get logical row mod */
+ rowMod = mega_mod64(row, raid->rowSize);
+ armQ = raid->rowSize-1-rowMod; /* index of Q drive */
+ arm = armQ+1+logArm; /* data always logically follows Q */
+ if (arm >= raid->rowSize) /* handle wrap condition */
+ arm -= raid->rowSize;
+ physArm = (u8)arm;
+ } else {
+ if (raid->modFactor == 0)
+ return FALSE;
+ physArm = MR_LdDataArmGet(ld, mega_mod64(stripRow,
+ raid->modFactor),
+ map);
+ }
+
+ if (raid->spanDepth == 1) {
+ span = 0;
+ *pdBlock = row << raid->stripeShift;
+ } else {
+ span = (u8)MR_GetSpanBlock(ld, row, pdBlock, map, &error_code);
+ if (error_code == 1)
+ return FALSE;
+ }
+
+ /* Get the array on which this span is present */
+ arRef = MR_LdSpanArrayGet(ld, span, map);
+ pd = MR_ArPdGet(arRef, physArm, map); /* Get the pd */
+
+ if (pd != MR_PD_INVALID)
+ /* Get dev handle from Pd. */
+ *pDevHandle = MR_PdDevHandleGet(pd, map);
+ else {
+ *pDevHandle = MR_PD_INVALID; /* set dev handle as invalid. */
+ if (raid->level >= 5)
+ pRAID_Context->regLockFlags = REGION_TYPE_EXCLUSIVE;
+ else if (raid->level == 1) {
+ /* Get alternate Pd. */
+ pd = MR_ArPdGet(arRef, physArm + 1, map);
+ if (pd != MR_PD_INVALID)
+ /* Get dev handle from Pd */
+ *pDevHandle = MR_PdDevHandleGet(pd, map);
+ }
+ retval = FALSE;
+ }
+
+ *pdBlock += stripRef + MR_LdSpanPtrGet(ld, span, map)->startBlk;
+ pRAID_Context->spanArm = (span << RAID_CTX_SPANARM_SPAN_SHIFT) |
+ physArm;
+ return retval;
+}
+
+/*
+******************************************************************************
+*
+* MR_BuildRaidContext function
+*
+* This function will initiate command processing. The start/end row and strip
+* information is calculated then the lock is acquired.
+* This function will return 0 if region lock was acquired OR return num strips
+*/
+u8
+MR_BuildRaidContext(struct IO_REQUEST_INFO *io_info,
+ struct RAID_CONTEXT *pRAID_Context,
+ struct MR_FW_RAID_MAP_ALL *map)
+{
+ struct MR_LD_RAID *raid;
+ u32 ld, stripSize, stripe_mask;
+ u64 endLba, endStrip, endRow, start_row, start_strip;
+ u64 regStart;
+ u32 regSize;
+ u8 num_strips, numRows;
+ u16 ref_in_start_stripe, ref_in_end_stripe;
+ u64 ldStartBlock;
+ u32 numBlocks, ldTgtId;
+ u8 isRead;
+ u8 retval = 0;
+
+ ldStartBlock = io_info->ldStartBlock;
+ numBlocks = io_info->numBlocks;
+ ldTgtId = io_info->ldTgtId;
+ isRead = io_info->isRead;
+
+ ld = MR_TargetIdToLdGet(ldTgtId, map);
+ raid = MR_LdRaidGet(ld, map);
+
+ stripSize = 1 << raid->stripeShift;
+ stripe_mask = stripSize-1;
+ /*
+ * calculate starting row and stripe, and number of strips and rows
+ */
+ start_strip = ldStartBlock >> raid->stripeShift;
+ ref_in_start_stripe = (u16)(ldStartBlock & stripe_mask);
+ endLba = ldStartBlock + numBlocks - 1;
+ ref_in_end_stripe = (u16)(endLba & stripe_mask);
+ endStrip = endLba >> raid->stripeShift;
+ num_strips = (u8)(endStrip - start_strip + 1); /* End strip */
+ if (raid->rowDataSize == 0)
+ return FALSE;
+ start_row = mega_div64_32(start_strip, raid->rowDataSize);
+ endRow = mega_div64_32(endStrip, raid->rowDataSize);
+ numRows = (u8)(endRow - start_row + 1);
+
+ /*
+ * calculate region info.
+ */
+
+ /* assume region is at the start of the first row */
+ regStart = start_row << raid->stripeShift;
+ /* assume this IO needs the full row - we'll adjust if not true */
+ regSize = stripSize;
+
+ /* If IO spans more than 1 strip, fp is not possible
+ FP is not possible for writes on non-0 raid levels
+ FP is not possible if LD is not capable */
+ if (num_strips > 1 || (!isRead && raid->level != 0) ||
+ !raid->capability.fpCapable) {
+ io_info->fpOkForIo = FALSE;
+ } else {
+ io_info->fpOkForIo = TRUE;
+ }
+
+ if (numRows == 1) {
+ /* single-strip IOs can always lock only the data needed */
+ if (num_strips == 1) {
+ regStart += ref_in_start_stripe;
+ regSize = numBlocks;
+ }
+ /* multi-strip IOs always need to full stripe locked */
+ } else {
+ if (start_strip == (start_row + 1) * raid->rowDataSize - 1) {
+ /* If the start strip is the last in the start row */
+ regStart += ref_in_start_stripe;
+ regSize = stripSize - ref_in_start_stripe;
+ /* initialize count to sectors from startref to end
+ of strip */
+ }
+
+ if (numRows > 2)
+ /* Add complete rows in the middle of the transfer */
+ regSize += (numRows-2) << raid->stripeShift;
+
+ /* if IO ends within first strip of last row */
+ if (endStrip == endRow*raid->rowDataSize)
+ regSize += ref_in_end_stripe+1;
+ else
+ regSize += stripSize;
+ }
+
+ pRAID_Context->timeoutValue = map->raidMap.fpPdIoTimeoutSec;
+ pRAID_Context->regLockFlags = (isRead) ? REGION_TYPE_SHARED_READ :
+ raid->regTypeReqOnWrite;
+ pRAID_Context->VirtualDiskTgtId = raid->targetId;
+ pRAID_Context->regLockRowLBA = regStart;
+ pRAID_Context->regLockLength = regSize;
+ pRAID_Context->configSeqNum = raid->seqNum;
+
+ /*Get Phy Params only if FP capable, or else leave it to MR firmware
+ to do the calculation.*/
+ if (io_info->fpOkForIo) {
+ retval = MR_GetPhyParams(ld, start_strip, ref_in_start_stripe,
+ &io_info->pdBlock,
+ &io_info->devHandle, pRAID_Context,
+ map);
+ /* If IO on an invalid Pd, then FP i snot possible */
+ if (io_info->devHandle == MR_PD_INVALID)
+ io_info->fpOkForIo = FALSE;
+ return retval;
+ } else if (isRead) {
+ uint stripIdx;
+ for (stripIdx = 0; stripIdx < num_strips; stripIdx++) {
+ if (!MR_GetPhyParams(ld, start_strip + stripIdx,
+ ref_in_start_stripe,
+ &io_info->pdBlock,
+ &io_info->devHandle,
+ pRAID_Context, map))
+ return TRUE;
+ }
+ }
+ return TRUE;
+}
+
+void
+mr_update_load_balance_params(struct MR_FW_RAID_MAP_ALL *map,
+ struct LD_LOAD_BALANCE_INFO *lbInfo)
+{
+ int ldCount;
+ u16 ld;
+ struct MR_LD_RAID *raid;
+
+ for (ldCount = 0; ldCount < MAX_LOGICAL_DRIVES; ldCount++) {
+ ld = MR_TargetIdToLdGet(ldCount, map);
+ if (ld >= MAX_LOGICAL_DRIVES) {
+ lbInfo[ldCount].loadBalanceFlag = 0;
+ continue;
+ }
+
+ raid = MR_LdRaidGet(ld, map);
+
+ /* Two drive Optimal RAID 1 */
+ if ((raid->level == 1) && (raid->rowSize == 2) &&
+ (raid->spanDepth == 1) && raid->ldState ==
+ MR_LD_STATE_OPTIMAL) {
+ u32 pd, arRef;
+
+ lbInfo[ldCount].loadBalanceFlag = 1;
+
+ /* Get the array on which this span is present */
+ arRef = MR_LdSpanArrayGet(ld, 0, map);
+
+ /* Get the Pd */
+ pd = MR_ArPdGet(arRef, 0, map);
+ /* Get dev handle from Pd */
+ lbInfo[ldCount].raid1DevHandle[0] =
+ MR_PdDevHandleGet(pd, map);
+ /* Get the Pd */
+ pd = MR_ArPdGet(arRef, 1, map);
+
+ /* Get the dev handle from Pd */
+ lbInfo[ldCount].raid1DevHandle[1] =
+ MR_PdDevHandleGet(pd, map);
+ } else
+ lbInfo[ldCount].loadBalanceFlag = 0;
+ }
+}
+
+u8 megasas_get_best_arm(struct LD_LOAD_BALANCE_INFO *lbInfo, u8 arm, u64 block,
+ u32 count)
+{
+ u16 pend0, pend1;
+ u64 diff0, diff1;
+ u8 bestArm;
+
+ /* get the pending cmds for the data and mirror arms */
+ pend0 = atomic_read(&lbInfo->scsi_pending_cmds[0]);
+ pend1 = atomic_read(&lbInfo->scsi_pending_cmds[1]);
+
+ /* Determine the disk whose head is nearer to the req. block */
+ diff0 = ABS_DIFF(block, lbInfo->last_accessed_block[0]);
+ diff1 = ABS_DIFF(block, lbInfo->last_accessed_block[1]);
+ bestArm = (diff0 <= diff1 ? 0 : 1);
+
+ if ((bestArm == arm && pend0 > pend1 + 16) ||
+ (bestArm != arm && pend1 > pend0 + 16))
+ bestArm ^= 1;
+
+ /* Update the last accessed block on the correct pd */
+ lbInfo->last_accessed_block[bestArm] = block + count - 1;
+
+ return bestArm;
+}
+
+u16 get_updated_dev_handle(struct LD_LOAD_BALANCE_INFO *lbInfo,
+ struct IO_REQUEST_INFO *io_info)
+{
+ u8 arm, old_arm;
+ u16 devHandle;
+
+ old_arm = lbInfo->raid1DevHandle[0] == io_info->devHandle ? 0 : 1;
+
+ /* get best new arm */
+ arm = megasas_get_best_arm(lbInfo, old_arm, io_info->ldStartBlock,
+ io_info->numBlocks);
+ devHandle = lbInfo->raid1DevHandle[arm];
+ atomic_inc(&lbInfo->scsi_pending_cmds[arm]);
+
+ return devHandle;
+}
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