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 */ 64 void 65 mr_update_load_balance_params(struct MR_FW_RAID_MAP_ALL *map, 66 struct LD_LOAD_BALANCE_INFO *lbInfo); 67 68 u32 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 **/ 86 u64 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 } 99 100 struct MR_LD_RAID *MR_LdRaidGet(u32 ld, struct MR_FW_RAID_MAP_ALL *map) 101 { 102 return &map->raidMap.ldSpanMap[ld].ldRaid; 103 } 104 105 static 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 } 111 112 static u8 MR_LdDataArmGet(u32 ld, u32 armIdx, struct MR_FW_RAID_MAP_ALL *map) 113 { 114 return map->raidMap.ldSpanMap[ld].dataArmMap[armIdx]; 115 } 116 117 static u16 MR_ArPdGet(u32 ar, u32 arm, struct MR_FW_RAID_MAP_ALL *map) 118 { 119 return map->raidMap.arMapInfo[ar].pd[arm]; 120 } 121 122 static 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 } 126 127 static u16 MR_PdDevHandleGet(u32 pd, struct MR_FW_RAID_MAP_ALL *map) 128 { 129 return map->raidMap.devHndlInfo[pd].curDevHdl; 130 } 131 132 u16 MR_GetLDTgtId(u32 ld, struct MR_FW_RAID_MAP_ALL *map) 133 { 134 return map->raidMap.ldSpanMap[ld].ldRaid.targetId; 135 } 136 137 u16 MR_TargetIdToLdGet(u32 ldTgtId, struct MR_FW_RAID_MAP_ALL *map) 138 { 139 return map->raidMap.ldTgtIdToLd[ldTgtId]; 140 } 141 142 static 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 */ 151 u8 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 } 174 175 u32 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 */ 230 u8 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 pRAID_Context->regLockFlags = REGION_TYPE_EXCLUSIVE; 287 else if (raid->level == 1) { 288 /* Get alternate Pd. */ 289 pd = MR_ArPdGet(arRef, physArm + 1, map); 290 if (pd != MR_PD_INVALID) 291 /* Get dev handle from Pd */ 292 *pDevHandle = MR_PdDevHandleGet(pd, map); 293 } 294 } 295 296 *pdBlock += stripRef + MR_LdSpanPtrGet(ld, span, map)->startBlk; 297 pRAID_Context->spanArm = (span << RAID_CTX_SPANARM_SPAN_SHIFT) | 298 physArm; 299 return retval; 300 } 301 302 /* 303 ****************************************************************************** 304 * 305 * MR_BuildRaidContext function 306 * 307 * This function will initiate command processing. The start/end row and strip 308 * information is calculated then the lock is acquired. 309 * This function will return 0 if region lock was acquired OR return num strips 310 */ 311 u8 312 MR_BuildRaidContext(struct megasas_instance *instance, 313 struct IO_REQUEST_INFO *io_info, 314 struct RAID_CONTEXT *pRAID_Context, 315 struct MR_FW_RAID_MAP_ALL *map) 316 { 317 struct MR_LD_RAID *raid; 318 u32 ld, stripSize, stripe_mask; 319 u64 endLba, endStrip, endRow, start_row, start_strip; 320 u64 regStart; 321 u32 regSize; 322 u8 num_strips, numRows; 323 u16 ref_in_start_stripe, ref_in_end_stripe; 324 u64 ldStartBlock; 325 u32 numBlocks, ldTgtId; 326 u8 isRead; 327 u8 retval = 0; 328 329 ldStartBlock = io_info->ldStartBlock; 330 numBlocks = io_info->numBlocks; 331 ldTgtId = io_info->ldTgtId; 332 isRead = io_info->isRead; 333 334 ld = MR_TargetIdToLdGet(ldTgtId, map); 335 raid = MR_LdRaidGet(ld, map); 336 337 stripSize = 1 << raid->stripeShift; 338 stripe_mask = stripSize-1; 339 /* 340 * calculate starting row and stripe, and number of strips and rows 341 */ 342 start_strip = ldStartBlock >> raid->stripeShift; 343 ref_in_start_stripe = (u16)(ldStartBlock & stripe_mask); 344 endLba = ldStartBlock + numBlocks - 1; 345 ref_in_end_stripe = (u16)(endLba & stripe_mask); 346 endStrip = endLba >> raid->stripeShift; 347 num_strips = (u8)(endStrip - start_strip + 1); /* End strip */ 348 if (raid->rowDataSize == 0) 349 return FALSE; 350 start_row = mega_div64_32(start_strip, raid->rowDataSize); 351 endRow = mega_div64_32(endStrip, raid->rowDataSize); 352 numRows = (u8)(endRow - start_row + 1); 353 354 /* 355 * calculate region info. 356 */ 357 358 /* assume region is at the start of the first row */ 359 regStart = start_row << raid->stripeShift; 360 /* assume this IO needs the full row - we'll adjust if not true */ 361 regSize = stripSize; 362 363 /* If IO spans more than 1 strip, fp is not possible 364 FP is not possible for writes on non-0 raid levels 365 FP is not possible if LD is not capable */ 366 if (num_strips > 1 || (!isRead && raid->level != 0) || 367 !raid->capability.fpCapable) { 368 io_info->fpOkForIo = FALSE; 369 } else { 370 io_info->fpOkForIo = TRUE; 371 } 372 373 if (numRows == 1) { 374 /* single-strip IOs can always lock only the data needed */ 375 if (num_strips == 1) { 376 regStart += ref_in_start_stripe; 377 regSize = numBlocks; 378 } 379 /* multi-strip IOs always need to full stripe locked */ 380 } else { 381 if (start_strip == (start_row + 1) * raid->rowDataSize - 1) { 382 /* If the start strip is the last in the start row */ 383 regStart += ref_in_start_stripe; 384 regSize = stripSize - ref_in_start_stripe; 385 /* initialize count to sectors from startref to end 386 of strip */ 387 } 388 389 if (numRows > 2) 390 /* Add complete rows in the middle of the transfer */ 391 regSize += (numRows-2) << raid->stripeShift; 392 393 /* if IO ends within first strip of last row */ 394 if (endStrip == endRow*raid->rowDataSize) 395 regSize += ref_in_end_stripe+1; 396 else 397 regSize += stripSize; 398 } 399 400 pRAID_Context->timeoutValue = map->raidMap.fpPdIoTimeoutSec; 401 if (instance->pdev->device == PCI_DEVICE_ID_LSI_INVADER) 402 pRAID_Context->regLockFlags = (isRead) ? 403 raid->regTypeReqOnRead : raid->regTypeReqOnWrite; 404 else 405 pRAID_Context->regLockFlags = (isRead) ? 406 REGION_TYPE_SHARED_READ : raid->regTypeReqOnWrite; 407 pRAID_Context->VirtualDiskTgtId = raid->targetId; 408 pRAID_Context->regLockRowLBA = regStart; 409 pRAID_Context->regLockLength = regSize; 410 pRAID_Context->configSeqNum = raid->seqNum; 411 412 /*Get Phy Params only if FP capable, or else leave it to MR firmware 413 to do the calculation.*/ 414 if (io_info->fpOkForIo) { 415 retval = MR_GetPhyParams(instance, ld, start_strip, 416 ref_in_start_stripe, 417 &io_info->pdBlock, 418 &io_info->devHandle, pRAID_Context, 419 map); 420 /* If IO on an invalid Pd, then FP i snot possible */ 421 if (io_info->devHandle == MR_PD_INVALID) 422 io_info->fpOkForIo = FALSE; 423 return retval; 424 } else if (isRead) { 425 uint stripIdx; 426 for (stripIdx = 0; stripIdx < num_strips; stripIdx++) { 427 if (!MR_GetPhyParams(instance, ld, 428 start_strip + stripIdx, 429 ref_in_start_stripe, 430 &io_info->pdBlock, 431 &io_info->devHandle, 432 pRAID_Context, map)) 433 return TRUE; 434 } 435 } 436 return TRUE; 437 } 438 439 void 440 mr_update_load_balance_params(struct MR_FW_RAID_MAP_ALL *map, 441 struct LD_LOAD_BALANCE_INFO *lbInfo) 442 { 443 int ldCount; 444 u16 ld; 445 struct MR_LD_RAID *raid; 446 447 for (ldCount = 0; ldCount < MAX_LOGICAL_DRIVES; ldCount++) { 448 ld = MR_TargetIdToLdGet(ldCount, map); 449 if (ld >= MAX_LOGICAL_DRIVES) { 450 lbInfo[ldCount].loadBalanceFlag = 0; 451 continue; 452 } 453 454 raid = MR_LdRaidGet(ld, map); 455 456 /* Two drive Optimal RAID 1 */ 457 if ((raid->level == 1) && (raid->rowSize == 2) && 458 (raid->spanDepth == 1) && raid->ldState == 459 MR_LD_STATE_OPTIMAL) { 460 u32 pd, arRef; 461 462 lbInfo[ldCount].loadBalanceFlag = 1; 463 464 /* Get the array on which this span is present */ 465 arRef = MR_LdSpanArrayGet(ld, 0, map); 466 467 /* Get the Pd */ 468 pd = MR_ArPdGet(arRef, 0, map); 469 /* Get dev handle from Pd */ 470 lbInfo[ldCount].raid1DevHandle[0] = 471 MR_PdDevHandleGet(pd, map); 472 /* Get the Pd */ 473 pd = MR_ArPdGet(arRef, 1, map); 474 475 /* Get the dev handle from Pd */ 476 lbInfo[ldCount].raid1DevHandle[1] = 477 MR_PdDevHandleGet(pd, map); 478 } else 479 lbInfo[ldCount].loadBalanceFlag = 0; 480 } 481 } 482 483 u8 megasas_get_best_arm(struct LD_LOAD_BALANCE_INFO *lbInfo, u8 arm, u64 block, 484 u32 count) 485 { 486 u16 pend0, pend1; 487 u64 diff0, diff1; 488 u8 bestArm; 489 490 /* get the pending cmds for the data and mirror arms */ 491 pend0 = atomic_read(&lbInfo->scsi_pending_cmds[0]); 492 pend1 = atomic_read(&lbInfo->scsi_pending_cmds[1]); 493 494 /* Determine the disk whose head is nearer to the req. block */ 495 diff0 = ABS_DIFF(block, lbInfo->last_accessed_block[0]); 496 diff1 = ABS_DIFF(block, lbInfo->last_accessed_block[1]); 497 bestArm = (diff0 <= diff1 ? 0 : 1); 498 499 if ((bestArm == arm && pend0 > pend1 + 16) || 500 (bestArm != arm && pend1 > pend0 + 16)) 501 bestArm ^= 1; 502 503 /* Update the last accessed block on the correct pd */ 504 lbInfo->last_accessed_block[bestArm] = block + count - 1; 505 506 return bestArm; 507 } 508 509 u16 get_updated_dev_handle(struct LD_LOAD_BALANCE_INFO *lbInfo, 510 struct IO_REQUEST_INFO *io_info) 511 { 512 u8 arm, old_arm; 513 u16 devHandle; 514 515 old_arm = lbInfo->raid1DevHandle[0] == io_info->devHandle ? 0 : 1; 516 517 /* get best new arm */ 518 arm = megasas_get_best_arm(lbInfo, old_arm, io_info->ldStartBlock, 519 io_info->numBlocks); 520 devHandle = lbInfo->raid1DevHandle[arm]; 521 atomic_inc(&lbInfo->scsi_pending_cmds[arm]); 522 523 return devHandle; 524 } 525