drivers/scsi/cxlflash/vlun.h

   1 /*
   2  * CXL Flash Device Driver
   3  *
   4  * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
   5  *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
   6  *
   7  * Copyright (C) 2015 IBM Corporation
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version
  12  * 2 of the License, or (at your option) any later version.
  13  */
  14
  15 #ifndef _CXLFLASH_VLUN_H
  16 #define _CXLFLASH_VLUN_H
  17
  18 /* RHT - Resource Handle Table */
  19 #define MC_RHT_NMASK      16    /* in bits */
  20 #define MC_CHUNK_SHIFT    MC_RHT_NMASK  /* shift to go from LBA to chunk# */
  21
  22 #define HIBIT             (BITS_PER_LONG - 1)
  23
  24 #define MAX_AUN_CLONE_CNT 0xFF
  25
  26 /*
  27  * LXT - LBA Translation Table
  28  *
  29  * +-------+-------+-------+-------+-------+-------+-------+---+---+
  30  * | RLBA_BASE                                     |LUN_IDX| P |SEL|
  31  * +-------+-------+-------+-------+-------+-------+-------+---+---+
  32  *
  33  * The LXT Entry contains the physical LBA where the chunk starts (RLBA_BASE).
  34  * AFU ORes the low order bits from the virtual LBA (offset into the chunk)
  35  * with RLBA_BASE. The result is the physical LBA to be sent to storage.
  36  * The LXT Entry also contains an index to a LUN TBL and a bitmask of which
  37  * outgoing (FC) * ports can be selected. The port select bit-mask is ANDed
  38  * with a global port select bit-mask maintained by the driver.
  39  * In addition, it has permission bits that are ANDed with the
  40  * RHT permissions to arrive at the final permissions for the chunk.
  41  *
  42  * LXT tables are allocated dynamically in groups. This is done to avoid
  43  * a malloc/free overhead each time the LXT has to grow or shrink.
  44  *
  45  * Based on the current lxt_cnt (used), it is always possible to know
  46  * how many are allocated (used+free). The number of allocated entries is
  47  * not stored anywhere.
  48  *
  49  * The LXT table is re-allocated whenever it needs to cross into another group.
  50  */
  51 #define LXT_GROUP_SIZE          8
  52 #define LXT_NUM_GROUPS(lxt_cnt) (((lxt_cnt) + 7)/8)     /* alloc'ed groups */
  53 #define LXT_LUNIDX_SHIFT  8     /* LXT entry, shift for LUN index */
  54 #define LXT_PERM_SHIFT    4     /* LXT entry, shift for permission bits */
  55
  56 struct ba_lun_info {
  57         u64 *lun_alloc_map;
  58         u32 lun_bmap_size;
  59         u32 total_aus;
  60         u64 free_aun_cnt;
  61
  62         /* indices to be used for elevator lookup of free map */
  63         u32 free_low_idx;
  64         u32 free_curr_idx;
  65         u32 free_high_idx;
  66
  67         u8 *aun_clone_map;
  68 };
  69
  70 struct ba_lun {
  71         u64 lun_id;
  72         u64 wwpn;
  73         size_t lsize;           /* LUN size in number of LBAs             */
  74         size_t lba_size;        /* LBA size in number of bytes            */
  75         size_t au_size;         /* Allocation Unit size in number of LBAs */
  76         struct ba_lun_info *ba_lun_handle;
  77 };
  78
  79 /* Block Allocator */
  80 struct blka {
  81         struct ba_lun ba_lun;
  82         u64 nchunk;             /* number of chunks */
  83         struct mutex mutex;
  84 };
  85
  86 #endif /* ifndef _CXLFLASH_SUPERPIPE_H */