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Diffstat (limited to 'drivers/scsi/cxlflash/vlun.h')
-rw-r--r-- | drivers/scsi/cxlflash/vlun.h | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/drivers/scsi/cxlflash/vlun.h b/drivers/scsi/cxlflash/vlun.h new file mode 100644 index 0000000000..68e3ea52fe --- /dev/null +++ b/drivers/scsi/cxlflash/vlun.h @@ -0,0 +1,82 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * CXL Flash Device Driver + * + * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation + * Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation + * + * Copyright (C) 2015 IBM Corporation + */ + +#ifndef _CXLFLASH_VLUN_H +#define _CXLFLASH_VLUN_H + +/* RHT - Resource Handle Table */ +#define MC_RHT_NMASK 16 /* in bits */ +#define MC_CHUNK_SHIFT MC_RHT_NMASK /* shift to go from LBA to chunk# */ + +#define HIBIT (BITS_PER_LONG - 1) + +#define MAX_AUN_CLONE_CNT 0xFF + +/* + * LXT - LBA Translation Table + * + * +-------+-------+-------+-------+-------+-------+-------+---+---+ + * | RLBA_BASE |LUN_IDX| P |SEL| + * +-------+-------+-------+-------+-------+-------+-------+---+---+ + * + * The LXT Entry contains the physical LBA where the chunk starts (RLBA_BASE). + * AFU ORes the low order bits from the virtual LBA (offset into the chunk) + * with RLBA_BASE. The result is the physical LBA to be sent to storage. + * The LXT Entry also contains an index to a LUN TBL and a bitmask of which + * outgoing (FC) * ports can be selected. The port select bit-mask is ANDed + * with a global port select bit-mask maintained by the driver. + * In addition, it has permission bits that are ANDed with the + * RHT permissions to arrive at the final permissions for the chunk. + * + * LXT tables are allocated dynamically in groups. This is done to avoid + * a malloc/free overhead each time the LXT has to grow or shrink. + * + * Based on the current lxt_cnt (used), it is always possible to know + * how many are allocated (used+free). The number of allocated entries is + * not stored anywhere. + * + * The LXT table is re-allocated whenever it needs to cross into another group. + */ +#define LXT_GROUP_SIZE 8 +#define LXT_NUM_GROUPS(lxt_cnt) (((lxt_cnt) + 7)/8) /* alloc'ed groups */ +#define LXT_LUNIDX_SHIFT 8 /* LXT entry, shift for LUN index */ +#define LXT_PERM_SHIFT 4 /* LXT entry, shift for permission bits */ + +struct ba_lun_info { + u64 *lun_alloc_map; + u32 lun_bmap_size; + u32 total_aus; + u64 free_aun_cnt; + + /* indices to be used for elevator lookup of free map */ + u32 free_low_idx; + u32 free_curr_idx; + u32 free_high_idx; + + u8 *aun_clone_map; +}; + +struct ba_lun { + u64 lun_id; + u64 wwpn; + size_t lsize; /* LUN size in number of LBAs */ + size_t lba_size; /* LBA size in number of bytes */ + size_t au_size; /* Allocation Unit size in number of LBAs */ + struct ba_lun_info *ba_lun_handle; +}; + +/* Block Allocator */ +struct blka { + struct ba_lun ba_lun; + u64 nchunk; /* number of chunks */ + struct mutex mutex; +}; + +#endif /* ifndef _CXLFLASH_SUPERPIPE_H */ |