staging: usbip: bugfix for isochronous packets and optimization
[zen-stable.git] / drivers / scsi / megaraid / megaraid_sas_fp.c
blob8fe3a45794fc454fa91fab83153528162dd9890e
1 /*
2 * Linux MegaRAID driver for SAS based RAID controllers
4 * Copyright (c) 2009-2011 LSI Corporation.
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.
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.
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
20 * FILE: megaraid_sas_fp.c
22 * Authors: LSI Corporation
23 * Sumant Patro
24 * Varad Talamacki
25 * Manoj Jose
27 * Send feedback to: <megaraidlinux@lsi.com>
29 * Mail to: LSI Corporation, 1621 Barber Lane, Milpitas, CA 95035
30 * ATTN: Linuxraid
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>
49 #include <scsi/scsi.h>
50 #include <scsi/scsi_cmnd.h>
51 #include <scsi/scsi_device.h>
52 #include <scsi/scsi_host.h>
54 #include "megaraid_sas_fusion.h"
55 #include <asm/div64.h>
57 #define ABS_DIFF(a, b) (((a) > (b)) ? ((a) - (b)) : ((b) - (a)))
58 #define MR_LD_STATE_OPTIMAL 3
59 #define FALSE 0
60 #define TRUE 1
62 /* Prototypes */
63 void
64 mr_update_load_balance_params(struct MR_FW_RAID_MAP_ALL *map,
65 struct LD_LOAD_BALANCE_INFO *lbInfo);
67 u32 mega_mod64(u64 dividend, u32 divisor)
69 u64 d;
70 u32 remainder;
72 if (!divisor)
73 printk(KERN_ERR "megasas : DIVISOR is zero, in div fn\n");
74 d = dividend;
75 remainder = do_div(d, divisor);
76 return remainder;
79 /**
80 * @param dividend : Dividend
81 * @param divisor : Divisor
83 * @return quotient
84 **/
85 u64 mega_div64_32(uint64_t dividend, uint32_t divisor)
87 u32 remainder;
88 u64 d;
90 if (!divisor)
91 printk(KERN_ERR "megasas : DIVISOR is zero in mod fn\n");
93 d = dividend;
94 remainder = do_div(d, divisor);
96 return d;
99 struct MR_LD_RAID *MR_LdRaidGet(u32 ld, struct MR_FW_RAID_MAP_ALL *map)
101 return &map->raidMap.ldSpanMap[ld].ldRaid;
104 static struct MR_SPAN_BLOCK_INFO *MR_LdSpanInfoGet(u32 ld,
105 struct MR_FW_RAID_MAP_ALL
106 *map)
108 return &map->raidMap.ldSpanMap[ld].spanBlock[0];
111 static u8 MR_LdDataArmGet(u32 ld, u32 armIdx, struct MR_FW_RAID_MAP_ALL *map)
113 return map->raidMap.ldSpanMap[ld].dataArmMap[armIdx];
116 static u16 MR_ArPdGet(u32 ar, u32 arm, struct MR_FW_RAID_MAP_ALL *map)
118 return map->raidMap.arMapInfo[ar].pd[arm];
121 static u16 MR_LdSpanArrayGet(u32 ld, u32 span, struct MR_FW_RAID_MAP_ALL *map)
123 return map->raidMap.ldSpanMap[ld].spanBlock[span].span.arrayRef;
126 static u16 MR_PdDevHandleGet(u32 pd, struct MR_FW_RAID_MAP_ALL *map)
128 return map->raidMap.devHndlInfo[pd].curDevHdl;
131 u16 MR_GetLDTgtId(u32 ld, struct MR_FW_RAID_MAP_ALL *map)
133 return map->raidMap.ldSpanMap[ld].ldRaid.targetId;
136 u16 MR_TargetIdToLdGet(u32 ldTgtId, struct MR_FW_RAID_MAP_ALL *map)
138 return map->raidMap.ldTgtIdToLd[ldTgtId];
141 static struct MR_LD_SPAN *MR_LdSpanPtrGet(u32 ld, u32 span,
142 struct MR_FW_RAID_MAP_ALL *map)
144 return &map->raidMap.ldSpanMap[ld].spanBlock[span].span;
148 * This function will validate Map info data provided by FW
150 u8 MR_ValidateMapInfo(struct MR_FW_RAID_MAP_ALL *map,
151 struct LD_LOAD_BALANCE_INFO *lbInfo)
153 struct MR_FW_RAID_MAP *pFwRaidMap = &map->raidMap;
155 if (pFwRaidMap->totalSize !=
156 (sizeof(struct MR_FW_RAID_MAP) -sizeof(struct MR_LD_SPAN_MAP) +
157 (sizeof(struct MR_LD_SPAN_MAP) *pFwRaidMap->ldCount))) {
158 printk(KERN_ERR "megasas: map info structure size 0x%x is not matching with ld count\n",
159 (unsigned int)((sizeof(struct MR_FW_RAID_MAP) -
160 sizeof(struct MR_LD_SPAN_MAP)) +
161 (sizeof(struct MR_LD_SPAN_MAP) *
162 pFwRaidMap->ldCount)));
163 printk(KERN_ERR "megasas: span map %x, pFwRaidMap->totalSize "
164 ": %x\n", (unsigned int)sizeof(struct MR_LD_SPAN_MAP),
165 pFwRaidMap->totalSize);
166 return 0;
169 mr_update_load_balance_params(map, lbInfo);
171 return 1;
174 u32 MR_GetSpanBlock(u32 ld, u64 row, u64 *span_blk,
175 struct MR_FW_RAID_MAP_ALL *map, int *div_error)
177 struct MR_SPAN_BLOCK_INFO *pSpanBlock = MR_LdSpanInfoGet(ld, map);
178 struct MR_QUAD_ELEMENT *quad;
179 struct MR_LD_RAID *raid = MR_LdRaidGet(ld, map);
180 u32 span, j;
182 for (span = 0; span < raid->spanDepth; span++, pSpanBlock++) {
184 for (j = 0; j < pSpanBlock->block_span_info.noElements; j++) {
185 quad = &pSpanBlock->block_span_info.quad[j];
187 if (quad->diff == 0) {
188 *div_error = 1;
189 return span;
191 if (quad->logStart <= row && row <= quad->logEnd &&
192 (mega_mod64(row-quad->logStart, quad->diff)) == 0) {
193 if (span_blk != NULL) {
194 u64 blk, debugBlk;
195 blk =
196 mega_div64_32(
197 (row-quad->logStart),
198 quad->diff);
199 debugBlk = blk;
201 blk = (blk + quad->offsetInSpan) <<
202 raid->stripeShift;
203 *span_blk = blk;
205 return span;
209 return span;
213 ******************************************************************************
215 * This routine calculates the arm, span and block for the specified stripe and
216 * reference in stripe.
218 * Inputs :
220 * ld - Logical drive number
221 * stripRow - Stripe number
222 * stripRef - Reference in stripe
224 * Outputs :
226 * span - Span number
227 * block - Absolute Block number in the physical disk
229 u8 MR_GetPhyParams(u32 ld, u64 stripRow, u16 stripRef, u64 *pdBlock,
230 u16 *pDevHandle, struct RAID_CONTEXT *pRAID_Context,
231 struct MR_FW_RAID_MAP_ALL *map)
233 struct MR_LD_RAID *raid = MR_LdRaidGet(ld, map);
234 u32 pd, arRef;
235 u8 physArm, span;
236 u64 row;
237 u8 retval = TRUE;
238 int error_code = 0;
240 row = mega_div64_32(stripRow, raid->rowDataSize);
242 if (raid->level == 6) {
243 /* logical arm within row */
244 u32 logArm = mega_mod64(stripRow, raid->rowDataSize);
245 u32 rowMod, armQ, arm;
247 if (raid->rowSize == 0)
248 return FALSE;
249 /* get logical row mod */
250 rowMod = mega_mod64(row, raid->rowSize);
251 armQ = raid->rowSize-1-rowMod; /* index of Q drive */
252 arm = armQ+1+logArm; /* data always logically follows Q */
253 if (arm >= raid->rowSize) /* handle wrap condition */
254 arm -= raid->rowSize;
255 physArm = (u8)arm;
256 } else {
257 if (raid->modFactor == 0)
258 return FALSE;
259 physArm = MR_LdDataArmGet(ld, mega_mod64(stripRow,
260 raid->modFactor),
261 map);
264 if (raid->spanDepth == 1) {
265 span = 0;
266 *pdBlock = row << raid->stripeShift;
267 } else {
268 span = (u8)MR_GetSpanBlock(ld, row, pdBlock, map, &error_code);
269 if (error_code == 1)
270 return FALSE;
273 /* Get the array on which this span is present */
274 arRef = MR_LdSpanArrayGet(ld, span, map);
275 pd = MR_ArPdGet(arRef, physArm, map); /* Get the pd */
277 if (pd != MR_PD_INVALID)
278 /* Get dev handle from Pd. */
279 *pDevHandle = MR_PdDevHandleGet(pd, map);
280 else {
281 *pDevHandle = MR_PD_INVALID; /* set dev handle as invalid. */
282 if (raid->level >= 5)
283 pRAID_Context->regLockFlags = REGION_TYPE_EXCLUSIVE;
284 else if (raid->level == 1) {
285 /* Get alternate Pd. */
286 pd = MR_ArPdGet(arRef, physArm + 1, map);
287 if (pd != MR_PD_INVALID)
288 /* Get dev handle from Pd */
289 *pDevHandle = MR_PdDevHandleGet(pd, map);
291 retval = FALSE;
294 *pdBlock += stripRef + MR_LdSpanPtrGet(ld, span, map)->startBlk;
295 pRAID_Context->spanArm = (span << RAID_CTX_SPANARM_SPAN_SHIFT) |
296 physArm;
297 return retval;
301 ******************************************************************************
303 * MR_BuildRaidContext function
305 * This function will initiate command processing. The start/end row and strip
306 * information is calculated then the lock is acquired.
307 * This function will return 0 if region lock was acquired OR return num strips
310 MR_BuildRaidContext(struct IO_REQUEST_INFO *io_info,
311 struct RAID_CONTEXT *pRAID_Context,
312 struct MR_FW_RAID_MAP_ALL *map)
314 struct MR_LD_RAID *raid;
315 u32 ld, stripSize, stripe_mask;
316 u64 endLba, endStrip, endRow, start_row, start_strip;
317 u64 regStart;
318 u32 regSize;
319 u8 num_strips, numRows;
320 u16 ref_in_start_stripe, ref_in_end_stripe;
321 u64 ldStartBlock;
322 u32 numBlocks, ldTgtId;
323 u8 isRead;
324 u8 retval = 0;
326 ldStartBlock = io_info->ldStartBlock;
327 numBlocks = io_info->numBlocks;
328 ldTgtId = io_info->ldTgtId;
329 isRead = io_info->isRead;
331 ld = MR_TargetIdToLdGet(ldTgtId, map);
332 raid = MR_LdRaidGet(ld, map);
334 stripSize = 1 << raid->stripeShift;
335 stripe_mask = stripSize-1;
337 * calculate starting row and stripe, and number of strips and rows
339 start_strip = ldStartBlock >> raid->stripeShift;
340 ref_in_start_stripe = (u16)(ldStartBlock & stripe_mask);
341 endLba = ldStartBlock + numBlocks - 1;
342 ref_in_end_stripe = (u16)(endLba & stripe_mask);
343 endStrip = endLba >> raid->stripeShift;
344 num_strips = (u8)(endStrip - start_strip + 1); /* End strip */
345 if (raid->rowDataSize == 0)
346 return FALSE;
347 start_row = mega_div64_32(start_strip, raid->rowDataSize);
348 endRow = mega_div64_32(endStrip, raid->rowDataSize);
349 numRows = (u8)(endRow - start_row + 1);
352 * calculate region info.
355 /* assume region is at the start of the first row */
356 regStart = start_row << raid->stripeShift;
357 /* assume this IO needs the full row - we'll adjust if not true */
358 regSize = stripSize;
360 /* If IO spans more than 1 strip, fp is not possible
361 FP is not possible for writes on non-0 raid levels
362 FP is not possible if LD is not capable */
363 if (num_strips > 1 || (!isRead && raid->level != 0) ||
364 !raid->capability.fpCapable) {
365 io_info->fpOkForIo = FALSE;
366 } else {
367 io_info->fpOkForIo = TRUE;
370 if (numRows == 1) {
371 /* single-strip IOs can always lock only the data needed */
372 if (num_strips == 1) {
373 regStart += ref_in_start_stripe;
374 regSize = numBlocks;
376 /* multi-strip IOs always need to full stripe locked */
377 } else {
378 if (start_strip == (start_row + 1) * raid->rowDataSize - 1) {
379 /* If the start strip is the last in the start row */
380 regStart += ref_in_start_stripe;
381 regSize = stripSize - ref_in_start_stripe;
382 /* initialize count to sectors from startref to end
383 of strip */
386 if (numRows > 2)
387 /* Add complete rows in the middle of the transfer */
388 regSize += (numRows-2) << raid->stripeShift;
390 /* if IO ends within first strip of last row */
391 if (endStrip == endRow*raid->rowDataSize)
392 regSize += ref_in_end_stripe+1;
393 else
394 regSize += stripSize;
397 pRAID_Context->timeoutValue = map->raidMap.fpPdIoTimeoutSec;
398 pRAID_Context->regLockFlags = (isRead) ? REGION_TYPE_SHARED_READ :
399 raid->regTypeReqOnWrite;
400 pRAID_Context->VirtualDiskTgtId = raid->targetId;
401 pRAID_Context->regLockRowLBA = regStart;
402 pRAID_Context->regLockLength = regSize;
403 pRAID_Context->configSeqNum = raid->seqNum;
405 /*Get Phy Params only if FP capable, or else leave it to MR firmware
406 to do the calculation.*/
407 if (io_info->fpOkForIo) {
408 retval = MR_GetPhyParams(ld, start_strip, ref_in_start_stripe,
409 &io_info->pdBlock,
410 &io_info->devHandle, pRAID_Context,
411 map);
412 /* If IO on an invalid Pd, then FP i snot possible */
413 if (io_info->devHandle == MR_PD_INVALID)
414 io_info->fpOkForIo = FALSE;
415 return retval;
416 } else if (isRead) {
417 uint stripIdx;
418 for (stripIdx = 0; stripIdx < num_strips; stripIdx++) {
419 if (!MR_GetPhyParams(ld, start_strip + stripIdx,
420 ref_in_start_stripe,
421 &io_info->pdBlock,
422 &io_info->devHandle,
423 pRAID_Context, map))
424 return TRUE;
427 return TRUE;
430 void
431 mr_update_load_balance_params(struct MR_FW_RAID_MAP_ALL *map,
432 struct LD_LOAD_BALANCE_INFO *lbInfo)
434 int ldCount;
435 u16 ld;
436 struct MR_LD_RAID *raid;
438 for (ldCount = 0; ldCount < MAX_LOGICAL_DRIVES; ldCount++) {
439 ld = MR_TargetIdToLdGet(ldCount, map);
440 if (ld >= MAX_LOGICAL_DRIVES) {
441 lbInfo[ldCount].loadBalanceFlag = 0;
442 continue;
445 raid = MR_LdRaidGet(ld, map);
447 /* Two drive Optimal RAID 1 */
448 if ((raid->level == 1) && (raid->rowSize == 2) &&
449 (raid->spanDepth == 1) && raid->ldState ==
450 MR_LD_STATE_OPTIMAL) {
451 u32 pd, arRef;
453 lbInfo[ldCount].loadBalanceFlag = 1;
455 /* Get the array on which this span is present */
456 arRef = MR_LdSpanArrayGet(ld, 0, map);
458 /* Get the Pd */
459 pd = MR_ArPdGet(arRef, 0, map);
460 /* Get dev handle from Pd */
461 lbInfo[ldCount].raid1DevHandle[0] =
462 MR_PdDevHandleGet(pd, map);
463 /* Get the Pd */
464 pd = MR_ArPdGet(arRef, 1, map);
466 /* Get the dev handle from Pd */
467 lbInfo[ldCount].raid1DevHandle[1] =
468 MR_PdDevHandleGet(pd, map);
469 } else
470 lbInfo[ldCount].loadBalanceFlag = 0;
474 u8 megasas_get_best_arm(struct LD_LOAD_BALANCE_INFO *lbInfo, u8 arm, u64 block,
475 u32 count)
477 u16 pend0, pend1;
478 u64 diff0, diff1;
479 u8 bestArm;
481 /* get the pending cmds for the data and mirror arms */
482 pend0 = atomic_read(&lbInfo->scsi_pending_cmds[0]);
483 pend1 = atomic_read(&lbInfo->scsi_pending_cmds[1]);
485 /* Determine the disk whose head is nearer to the req. block */
486 diff0 = ABS_DIFF(block, lbInfo->last_accessed_block[0]);
487 diff1 = ABS_DIFF(block, lbInfo->last_accessed_block[1]);
488 bestArm = (diff0 <= diff1 ? 0 : 1);
490 if ((bestArm == arm && pend0 > pend1 + 16) ||
491 (bestArm != arm && pend1 > pend0 + 16))
492 bestArm ^= 1;
494 /* Update the last accessed block on the correct pd */
495 lbInfo->last_accessed_block[bestArm] = block + count - 1;
497 return bestArm;
500 u16 get_updated_dev_handle(struct LD_LOAD_BALANCE_INFO *lbInfo,
501 struct IO_REQUEST_INFO *io_info)
503 u8 arm, old_arm;
504 u16 devHandle;
506 old_arm = lbInfo->raid1DevHandle[0] == io_info->devHandle ? 0 : 1;
508 /* get best new arm */
509 arm = megasas_get_best_arm(lbInfo, old_arm, io_info->ldStartBlock,
510 io_info->numBlocks);
511 devHandle = lbInfo->raid1DevHandle[arm];
512 atomic_inc(&lbInfo->scsi_pending_cmds[arm]);
514 return devHandle;