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-rw-r--r--drivers/scsi/cxlflash/vlun.h82
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 */