drivers/scsi/cxlflash/vlun.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * CXL Flash Device Driver
   4  *
   5  * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
   6  *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
   7  *
   8  * Copyright (C) 2015 IBM Corporation
   9  */
  10
  11 #ifndef _CXLFLASH_VLUN_H
  12 #define _CXLFLASH_VLUN_H
  13
  14 /* RHT - Resource Handle Table */
  15 #define MC_RHT_NMASK      16    /* in bits */
  16 #define MC_CHUNK_SHIFT    MC_RHT_NMASK  /* shift to go from LBA to chunk# */
  17
  18 #define HIBIT             (BITS_PER_LONG - 1)
  19
  20 #define MAX_AUN_CLONE_CNT 0xFF
  21
  22 /*
  23  * LXT - LBA Translation Table
  24  *
  25  * +-------+-------+-------+-------+-------+-------+-------+---+---+
  26  * | RLBA_BASE                                     |LUN_IDX| P |SEL|
  27  * +-------+-------+-------+-------+-------+-------+-------+---+---+
  28  *
  29  * The LXT Entry contains the physical LBA where the chunk starts (RLBA_BASE).
  30  * AFU ORes the low order bits from the virtual LBA (offset into the chunk)
  31  * with RLBA_BASE. The result is the physical LBA to be sent to storage.
  32  * The LXT Entry also contains an index to a LUN TBL and a bitmask of which
  33  * outgoing (FC) * ports can be selected. The port select bit-mask is ANDed
  34  * with a global port select bit-mask maintained by the driver.
  35  * In addition, it has permission bits that are ANDed with the
  36  * RHT permissions to arrive at the final permissions for the chunk.
  37  *
  38  * LXT tables are allocated dynamically in groups. This is done to avoid
  39  * a malloc/free overhead each time the LXT has to grow or shrink.
  40  *
  41  * Based on the current lxt_cnt (used), it is always possible to know
  42  * how many are allocated (used+free). The number of allocated entries is
  43  * not stored anywhere.
  44  *
  45  * The LXT table is re-allocated whenever it needs to cross into another group.
  46  */
  47 #define LXT_GROUP_SIZE          8
  48 #define LXT_NUM_GROUPS(lxt_cnt) (((lxt_cnt) + 7)/8)     /* alloc'ed groups */
  49 #define LXT_LUNIDX_SHIFT  8     /* LXT entry, shift for LUN index */
  50 #define LXT_PERM_SHIFT    4     /* LXT entry, shift for permission bits */
  51
  52 struct ba_lun_info {
  53         u64 *lun_alloc_map;
  54         u32 lun_bmap_size;
  55         u32 total_aus;
  56         u64 free_aun_cnt;
  57
  58         /* indices to be used for elevator lookup of free map */
  59         u32 free_low_idx;
  60         u32 free_curr_idx;
  61         u32 free_high_idx;
  62
  63         u8 *aun_clone_map;
  64 };
  65
  66 struct ba_lun {
  67         u64 lun_id;
  68         u64 wwpn;
  69         size_t lsize;           /* LUN size in number of LBAs             */
  70         size_t lba_size;        /* LBA size in number of bytes            */
  71         size_t au_size;         /* Allocation Unit size in number of LBAs */
  72         struct ba_lun_info *ba_lun_handle;
  73 };
  74
  75 /* Block Allocator */
  76 struct blka {
  77         struct ba_lun ba_lun;
  78         u64 nchunk;             /* number of chunks */
  79         struct mutex mutex;
  80 };
  81
  82 #endif /* ifndef _CXLFLASH_SUPERPIPE_H */