LXR linux/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
  56struct 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
  70struct 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 */
  80struct 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 */
  87