LXR linux/drivers/scsi/megaraid/megaraid_sas

   1/*
   2 *  Linux MegaRAID driver for SAS based RAID controllers
   3 *
   4 *  Copyright (c) 2009-2011  LSI Corporation.
   5 *
   6 *  This program is free software; you can redistribute it and/or
   7 *  modify it under the terms of the GNU General Public License
   8 *  as published by the Free Software Foundation; either version 2
   9 *  of the License, or (at your option) any later version.
  10 *
  11 *  This program is distributed in the hope that it will be useful,
  12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *  GNU General Public License for more details.
  15 *
  16 *  You should have received a copy of the GNU General Public License
  17 *  along with this program; if not, write to the Free Software
  18 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19 *
  20 *  FILE: megaraid_sas_fp.c
  21 *
  22 *  Authors: LSI Corporation
  23 *           Sumant Patro
  24 *           Varad Talamacki
  25 *           Manoj Jose
  26 *
  27 *  Send feedback to: <megaraidlinux@lsi.com>
  28 *
  29 *  Mail to: LSI Corporation, 1621 Barber Lane, Milpitas, CA 95035
  30 *     ATTN: Linuxraid
  31 */
  32
  33#include <linux/kernel.h>
  34#include <linux/types.h>
  35#include <linux/pci.h>
  36#include <linux/list.h>
  37#include <linux/moduleparam.h>
  38#include <linux/module.h>
  39#include <linux/spinlock.h>
  40#include <linux/interrupt.h>
  41#include <linux/delay.h>
  42#include <linux/uio.h>
  43#include <linux/uaccess.h>
  44#include <linux/fs.h>
  45#include <linux/compat.h>
  46#include <linux/blkdev.h>
  47#include <linux/poll.h>
  48
  49#include <scsi/scsi.h>
  50#include <scsi/scsi_cmnd.h>
  51#include <scsi/scsi_device.h>
  52#include <scsi/scsi_host.h>
  53
  54#include "megaraid_sas_fusion.h"
  55#include "megaraid_sas.h"
  56#include <asm/div64.h>
  57
  58#define ABS_DIFF(a, b)   (((a) > (b)) ? ((a) - (b)) : ((b) - (a)))
  59#define MR_LD_STATE_OPTIMAL 3
  60#define FALSE 0
  61#define TRUE 1
  62
  63/* Prototypes */
  64void
  65mr_update_load_balance_params(struct MR_FW_RAID_MAP_ALL *map,
  66                              struct LD_LOAD_BALANCE_INFO *lbInfo);
  67
  68u32 mega_mod64(u64 dividend, u32 divisor)
  69{
  70        u64 d;
  71        u32 remainder;
  72
  73        if (!divisor)
  74                printk(KERN_ERR "megasas : DIVISOR is zero, in div fn\n");
  75        d = dividend;
  76        remainder = do_div(d, divisor);
  77        return remainder;
  78}
  79
  80/**
  81 * @param dividend    : Dividend
  82 * @param divisor    : Divisor
  83 *
  84 * @return quotient
  85 **/
  86u64 mega_div64_32(uint64_t dividend, uint32_t divisor)
  87{
  88        u32 remainder;
  89        u64 d;
  90
  91        if (!divisor)
  92                printk(KERN_ERR "megasas : DIVISOR is zero in mod fn\n");
  93
  94        d = dividend;
  95        remainder = do_div(d, divisor);
  96
  97        return d;
  98}
  99
 100struct MR_LD_RAID *MR_LdRaidGet(u32 ld, struct MR_FW_RAID_MAP_ALL *map)
 101{
 102        return &map->raidMap.ldSpanMap[ld].ldRaid;
 103}
 104
 105static struct MR_SPAN_BLOCK_INFO *MR_LdSpanInfoGet(u32 ld,
 106                                                   struct MR_FW_RAID_MAP_ALL
 107                                                   *map)
 108{
 109        return &map->raidMap.ldSpanMap[ld].spanBlock[0];
 110}
 111
 112static u8 MR_LdDataArmGet(u32 ld, u32 armIdx, struct MR_FW_RAID_MAP_ALL *map)
 113{
 114        return map->raidMap.ldSpanMap[ld].dataArmMap[armIdx];
 115}
 116
 117static u16 MR_ArPdGet(u32 ar, u32 arm, struct MR_FW_RAID_MAP_ALL *map)
 118{
 119        return map->raidMap.arMapInfo[ar].pd[arm];
 120}
 121
 122static u16 MR_LdSpanArrayGet(u32 ld, u32 span, struct MR_FW_RAID_MAP_ALL *map)
 123{
 124        return map->raidMap.ldSpanMap[ld].spanBlock[span].span.arrayRef;
 125}
 126
 127static u16 MR_PdDevHandleGet(u32 pd, struct MR_FW_RAID_MAP_ALL *map)
 128{
 129        return map->raidMap.devHndlInfo[pd].curDevHdl;
 130}
 131
 132u16 MR_GetLDTgtId(u32 ld, struct MR_FW_RAID_MAP_ALL *map)
 133{
 134        return map->raidMap.ldSpanMap[ld].ldRaid.targetId;
 135}
 136
 137u16 MR_TargetIdToLdGet(u32 ldTgtId, struct MR_FW_RAID_MAP_ALL *map)
 138{
 139        return map->raidMap.ldTgtIdToLd[ldTgtId];
 140}
 141
 142static struct MR_LD_SPAN *MR_LdSpanPtrGet(u32 ld, u32 span,
 143                                          struct MR_FW_RAID_MAP_ALL *map)
 144{
 145        return &map->raidMap.ldSpanMap[ld].spanBlock[span].span;
 146}
 147
 148/*
 149 * This function will validate Map info data provided by FW
 150 */
 151u8 MR_ValidateMapInfo(struct MR_FW_RAID_MAP_ALL *map,
 152                      struct LD_LOAD_BALANCE_INFO *lbInfo)
 153{
 154        struct MR_FW_RAID_MAP *pFwRaidMap = &map->raidMap;
 155
 156        if (pFwRaidMap->totalSize !=
 157            (sizeof(struct MR_FW_RAID_MAP) -sizeof(struct MR_LD_SPAN_MAP) +
 158             (sizeof(struct MR_LD_SPAN_MAP) *pFwRaidMap->ldCount))) {
 159                printk(KERN_ERR "megasas: map info structure size 0x%x is not matching with ld count\n",
 160                       (unsigned int)((sizeof(struct MR_FW_RAID_MAP) -
 161                                       sizeof(struct MR_LD_SPAN_MAP)) +
 162                                      (sizeof(struct MR_LD_SPAN_MAP) *
 163                                       pFwRaidMap->ldCount)));
 164                printk(KERN_ERR "megasas: span map %x, pFwRaidMap->totalSize "
 165                       ": %x\n", (unsigned int)sizeof(struct MR_LD_SPAN_MAP),
 166                       pFwRaidMap->totalSize);
 167                return 0;
 168        }
 169
 170        mr_update_load_balance_params(map, lbInfo);
 171
 172        return 1;
 173}
 174
 175u32 MR_GetSpanBlock(u32 ld, u64 row, u64 *span_blk,
 176                    struct MR_FW_RAID_MAP_ALL *map, int *div_error)
 177{
 178        struct MR_SPAN_BLOCK_INFO *pSpanBlock = MR_LdSpanInfoGet(ld, map);
 179        struct MR_QUAD_ELEMENT    *quad;
 180        struct MR_LD_RAID         *raid = MR_LdRaidGet(ld, map);
 181        u32                span, j;
 182
 183        for (span = 0; span < raid->spanDepth; span++, pSpanBlock++) {
 184
 185                for (j = 0; j < pSpanBlock->block_span_info.noElements; j++) {
 186                        quad = &pSpanBlock->block_span_info.quad[j];
 187
 188                        if (quad->diff == 0) {
 189                                *div_error = 1;
 190                                return span;
 191                        }
 192                        if (quad->logStart <= row  &&  row <= quad->logEnd  &&
 193                            (mega_mod64(row-quad->logStart, quad->diff)) == 0) {
 194                                if (span_blk != NULL) {
 195                                        u64  blk, debugBlk;
 196                                        blk =
 197                                                mega_div64_32(
 198                                                        (row-quad->logStart),
 199                                                        quad->diff);
 200                                        debugBlk = blk;
 201
 202                                        blk = (blk + quad->offsetInSpan) <<
 203                                                raid->stripeShift;
 204                                        *span_blk = blk;
 205                                }
 206                                return span;
 207                        }
 208                }
 209        }
 210        return span;
 211}
 212
 213/*
 214******************************************************************************
 215*
 216* This routine calculates the arm, span and block for the specified stripe and
 217* reference in stripe.
 218*
 219* Inputs :
 220*
 221*    ld   - Logical drive number
 222*    stripRow        - Stripe number
 223*    stripRef    - Reference in stripe
 224*
 225* Outputs :
 226*
 227*    span          - Span number
 228*    block         - Absolute Block number in the physical disk
 229*/
 230u8 MR_GetPhyParams(struct megasas_instance *instance, u32 ld, u64 stripRow,
 231                   u16 stripRef, u64 *pdBlock, u16 *pDevHandle,
 232                   struct RAID_CONTEXT *pRAID_Context,
 233                   struct MR_FW_RAID_MAP_ALL *map)
 234{
 235        struct MR_LD_RAID  *raid = MR_LdRaidGet(ld, map);
 236        u32         pd, arRef;
 237        u8          physArm, span;
 238        u64         row;
 239        u8          retval = TRUE;
 240        int         error_code = 0;
 241
 242        row =  mega_div64_32(stripRow, raid->rowDataSize);
 243
 244        if (raid->level == 6) {
 245                /* logical arm within row */
 246                u32 logArm =  mega_mod64(stripRow, raid->rowDataSize);
 247                u32 rowMod, armQ, arm;
 248
 249                if (raid->rowSize == 0)
 250                        return FALSE;
 251                /* get logical row mod */
 252                rowMod = mega_mod64(row, raid->rowSize);
 253                armQ = raid->rowSize-1-rowMod; /* index of Q drive */
 254                arm = armQ+1+logArm; /* data always logically follows Q */
 255                if (arm >= raid->rowSize) /* handle wrap condition */
 256                        arm -= raid->rowSize;
 257                physArm = (u8)arm;
 258        } else  {
 259                if (raid->modFactor == 0)
 260                        return FALSE;
 261                physArm = MR_LdDataArmGet(ld,  mega_mod64(stripRow,
 262                                                          raid->modFactor),
 263                                          map);
 264        }
 265
 266        if (raid->spanDepth == 1) {
 267                span = 0;
 268                *pdBlock = row << raid->stripeShift;
 269        } else {
 270                span = (u8)MR_GetSpanBlock(ld, row, pdBlock, map, &error_code);
 271                if (error_code == 1)
 272                        return FALSE;
 273        }
 274
 275        /* Get the array on which this span is present */
 276        arRef       = MR_LdSpanArrayGet(ld, span, map);
 277        pd          = MR_ArPdGet(arRef, physArm, map); /* Get the pd */
 278
 279        if (pd != MR_PD_INVALID)
 280                /* Get dev handle from Pd. */
 281                *pDevHandle = MR_PdDevHandleGet(pd, map);
 282        else {
 283                *pDevHandle = MR_PD_INVALID; /* set dev handle as invalid. */
 284                if ((raid->level >= 5) &&
 285                    ((instance->pdev->device != PCI_DEVICE_ID_LSI_INVADER) ||
 286                     (instance->pdev->device == PCI_DEVICE_ID_LSI_INVADER &&
 287                      raid->regTypeReqOnRead != REGION_TYPE_UNUSED)))
 288                        pRAID_Context->regLockFlags = REGION_TYPE_EXCLUSIVE;
 289                else if (raid->level == 1) {
 290                        /* Get alternate Pd. */
 291                        pd = MR_ArPdGet(arRef, physArm + 1, map);
 292                        if (pd != MR_PD_INVALID)
 293                                /* Get dev handle from Pd */
 294                                *pDevHandle = MR_PdDevHandleGet(pd, map);
 295                }
 296        }
 297
 298        *pdBlock += stripRef + MR_LdSpanPtrGet(ld, span, map)->startBlk;
 299        pRAID_Context->spanArm = (span << RAID_CTX_SPANARM_SPAN_SHIFT) |
 300                physArm;
 301        return retval;
 302}
 303
 304/*
 305******************************************************************************
 306*
 307* MR_BuildRaidContext function
 308*
 309* This function will initiate command processing.  The start/end row and strip
 310* information is calculated then the lock is acquired.
 311* This function will return 0 if region lock was acquired OR return num strips
 312*/
 313u8
 314MR_BuildRaidContext(struct megasas_instance *instance,
 315                    struct IO_REQUEST_INFO *io_info,
 316                    struct RAID_CONTEXT *pRAID_Context,
 317                    struct MR_FW_RAID_MAP_ALL *map)
 318{
 319        struct MR_LD_RAID  *raid;
 320        u32         ld, stripSize, stripe_mask;
 321        u64         endLba, endStrip, endRow, start_row, start_strip;
 322        u64         regStart;
 323        u32         regSize;
 324        u8          num_strips, numRows;
 325        u16         ref_in_start_stripe, ref_in_end_stripe;
 326        u64         ldStartBlock;
 327        u32         numBlocks, ldTgtId;
 328        u8          isRead;
 329        u8          retval = 0;
 330
 331        ldStartBlock = io_info->ldStartBlock;
 332        numBlocks = io_info->numBlocks;
 333        ldTgtId = io_info->ldTgtId;
 334        isRead = io_info->isRead;
 335
 336        ld = MR_TargetIdToLdGet(ldTgtId, map);
 337        raid = MR_LdRaidGet(ld, map);
 338
 339        stripSize = 1 << raid->stripeShift;
 340        stripe_mask = stripSize-1;
 341        /*
 342         * calculate starting row and stripe, and number of strips and rows
 343         */
 344        start_strip         = ldStartBlock >> raid->stripeShift;
 345        ref_in_start_stripe = (u16)(ldStartBlock & stripe_mask);
 346        endLba              = ldStartBlock + numBlocks - 1;
 347        ref_in_end_stripe   = (u16)(endLba & stripe_mask);
 348        endStrip            = endLba >> raid->stripeShift;
 349        num_strips          = (u8)(endStrip - start_strip + 1); /* End strip */
 350        if (raid->rowDataSize == 0)
 351                return FALSE;
 352        start_row           =  mega_div64_32(start_strip, raid->rowDataSize);
 353        endRow              =  mega_div64_32(endStrip, raid->rowDataSize);
 354        numRows             = (u8)(endRow - start_row + 1);
 355
 356        /*
 357         * calculate region info.
 358         */
 359
 360        /* assume region is at the start of the first row */
 361        regStart            = start_row << raid->stripeShift;
 362        /* assume this IO needs the full row - we'll adjust if not true */
 363        regSize             = stripSize;
 364
 365        /* Check if we can send this I/O via FastPath */
 366        if (raid->capability.fpCapable) {
 367                if (isRead)
 368                        io_info->fpOkForIo = (raid->capability.fpReadCapable &&
 369                                              ((num_strips == 1) ||
 370                                               raid->capability.
 371                                               fpReadAcrossStripe));
 372                else
 373                        io_info->fpOkForIo = (raid->capability.fpWriteCapable &&
 374                                              ((num_strips == 1) ||
 375                                               raid->capability.
 376                                               fpWriteAcrossStripe));
 377        } else
 378                io_info->fpOkForIo = FALSE;
 379
 380        if (numRows == 1) {
 381                /* single-strip IOs can always lock only the data needed */
 382                if (num_strips == 1) {
 383                        regStart += ref_in_start_stripe;
 384                        regSize = numBlocks;
 385                }
 386                /* multi-strip IOs always need to full stripe locked */
 387        } else {
 388                if (start_strip == (start_row + 1) * raid->rowDataSize - 1) {
 389                        /* If the start strip is the last in the start row */
 390                        regStart += ref_in_start_stripe;
 391                        regSize = stripSize - ref_in_start_stripe;
 392                        /* initialize count to sectors from startref to end
 393                           of strip */
 394                }
 395
 396                if (numRows > 2)
 397                        /* Add complete rows in the middle of the transfer */
 398                        regSize += (numRows-2) << raid->stripeShift;
 399
 400                /* if IO ends within first strip of last row */
 401                if (endStrip == endRow*raid->rowDataSize)
 402                        regSize += ref_in_end_stripe+1;
 403                else
 404                        regSize += stripSize;
 405        }
 406
 407        pRAID_Context->timeoutValue     = map->raidMap.fpPdIoTimeoutSec;
 408        if (instance->pdev->device == PCI_DEVICE_ID_LSI_INVADER)
 409                pRAID_Context->regLockFlags = (isRead) ?
 410                        raid->regTypeReqOnRead : raid->regTypeReqOnWrite;
 411        else
 412                pRAID_Context->regLockFlags = (isRead) ?
 413                        REGION_TYPE_SHARED_READ : raid->regTypeReqOnWrite;
 414        pRAID_Context->VirtualDiskTgtId = raid->targetId;
 415        pRAID_Context->regLockRowLBA    = regStart;
 416        pRAID_Context->regLockLength    = regSize;
 417        pRAID_Context->configSeqNum     = raid->seqNum;
 418
 419        /*Get Phy Params only if FP capable, or else leave it to MR firmware
 420          to do the calculation.*/
 421        if (io_info->fpOkForIo) {
 422                retval = MR_GetPhyParams(instance, ld, start_strip,
 423                                         ref_in_start_stripe,
 424                                         &io_info->pdBlock,
 425                                         &io_info->devHandle, pRAID_Context,
 426                                         map);
 427                /* If IO on an invalid Pd, then FP i snot possible */
 428                if (io_info->devHandle == MR_PD_INVALID)
 429                        io_info->fpOkForIo = FALSE;
 430                return retval;
 431        } else if (isRead) {
 432                uint stripIdx;
 433                for (stripIdx = 0; stripIdx < num_strips; stripIdx++) {
 434                        if (!MR_GetPhyParams(instance, ld,
 435                                             start_strip + stripIdx,
 436                                             ref_in_start_stripe,
 437                                             &io_info->pdBlock,
 438                                             &io_info->devHandle,
 439                                             pRAID_Context, map))
 440                                return TRUE;
 441                }
 442        }
 443        return TRUE;
 444}
 445
 446void
 447mr_update_load_balance_params(struct MR_FW_RAID_MAP_ALL *map,
 448                              struct LD_LOAD_BALANCE_INFO *lbInfo)
 449{
 450        int ldCount;
 451        u16 ld;
 452        struct MR_LD_RAID *raid;
 453
 454        for (ldCount = 0; ldCount < MAX_LOGICAL_DRIVES; ldCount++) {
 455                ld = MR_TargetIdToLdGet(ldCount, map);
 456                if (ld >= MAX_LOGICAL_DRIVES) {
 457                        lbInfo[ldCount].loadBalanceFlag = 0;
 458                        continue;
 459                }
 460
 461                raid = MR_LdRaidGet(ld, map);
 462
 463                /* Two drive Optimal RAID 1 */
 464                if ((raid->level == 1)  &&  (raid->rowSize == 2) &&
 465                    (raid->spanDepth == 1) && raid->ldState ==
 466                    MR_LD_STATE_OPTIMAL) {
 467                        u32 pd, arRef;
 468
 469                        lbInfo[ldCount].loadBalanceFlag = 1;
 470
 471                        /* Get the array on which this span is present */
 472                        arRef = MR_LdSpanArrayGet(ld, 0, map);
 473
 474                        /* Get the Pd */
 475                        pd = MR_ArPdGet(arRef, 0, map);
 476                        /* Get dev handle from Pd */
 477                        lbInfo[ldCount].raid1DevHandle[0] =
 478                                MR_PdDevHandleGet(pd, map);
 479                        /* Get the Pd */
 480                        pd = MR_ArPdGet(arRef, 1, map);
 481
 482                        /* Get the dev handle from Pd */
 483                        lbInfo[ldCount].raid1DevHandle[1] =
 484                                MR_PdDevHandleGet(pd, map);
 485                } else
 486                        lbInfo[ldCount].loadBalanceFlag = 0;
 487        }
 488}
 489
 490u8 megasas_get_best_arm(struct LD_LOAD_BALANCE_INFO *lbInfo, u8 arm, u64 block,
 491                        u32 count)
 492{
 493        u16     pend0, pend1;
 494        u64     diff0, diff1;
 495        u8      bestArm;
 496
 497        /* get the pending cmds for the data and mirror arms */
 498        pend0 = atomic_read(&lbInfo->scsi_pending_cmds[0]);
 499        pend1 = atomic_read(&lbInfo->scsi_pending_cmds[1]);
 500
 501        /* Determine the disk whose head is nearer to the req. block */
 502        diff0 = ABS_DIFF(block, lbInfo->last_accessed_block[0]);
 503        diff1 = ABS_DIFF(block, lbInfo->last_accessed_block[1]);
 504        bestArm = (diff0 <= diff1 ? 0 : 1);
 505
 506        if ((bestArm == arm && pend0 > pend1 + 16)  ||
 507            (bestArm != arm && pend1 > pend0 + 16))
 508                bestArm ^= 1;
 509
 510        /* Update the last accessed block on the correct pd */
 511        lbInfo->last_accessed_block[bestArm] = block + count - 1;
 512
 513        return bestArm;
 514}
 515
 516u16 get_updated_dev_handle(struct LD_LOAD_BALANCE_INFO *lbInfo,
 517                           struct IO_REQUEST_INFO *io_info)
 518{
 519        u8 arm, old_arm;
 520        u16 devHandle;
 521
 522        old_arm = lbInfo->raid1DevHandle[0] == io_info->devHandle ? 0 : 1;
 523
 524        /* get best new arm */
 525        arm  = megasas_get_best_arm(lbInfo, old_arm, io_info->ldStartBlock,
 526                                    io_info->numBlocks);
 527        devHandle = lbInfo->raid1DevHandle[arm];
 528        atomic_inc(&lbInfo->scsi_pending_cmds[arm]);
 529
 530        return devHandle;
 531}
 532