drivers/scsi/cxlflash/common.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_COMMON_H
  16 #define _CXLFLASH_COMMON_H
  17
  18 #include <linux/list.h>
  19 #include <linux/rwsem.h>
  20 #include <linux/types.h>
  21 #include <scsi/scsi.h>
  22 #include <scsi/scsi_cmnd.h>
  23 #include <scsi/scsi_device.h>
  24
  25 extern const struct file_operations cxlflash_cxl_fops;
  26
  27 #define MAX_CONTEXT  CXLFLASH_MAX_CONTEXT       /* num contexts per afu */
  28
  29 #define CXLFLASH_BLOCK_SIZE     4096    /* 4K blocks */
  30 #define CXLFLASH_MAX_XFER_SIZE  16777216        /* 16MB transfer */
  31 #define CXLFLASH_MAX_SECTORS    (CXLFLASH_MAX_XFER_SIZE/512)    /* SCSI wants
  32                                                                    max_sectors
  33                                                                    in units of
  34                                                                    512 byte
  35                                                                    sectors
  36                                                                 */
  37
  38 #define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry))
  39
  40 /* AFU command retry limit */
  41 #define MC_RETRY_CNT         5  /* sufficient for SCSI check and
  42                                    certain AFU errors */
  43
  44 /* Command management definitions */
  45 #define CXLFLASH_NUM_CMDS       (2 * CXLFLASH_MAX_CMDS) /* Must be a pow2 for
  46                                                            alignment and more
  47                                                            efficient array
  48                                                            index derivation
  49                                                          */
  50
  51 #define CXLFLASH_MAX_CMDS               256
  52 #define CXLFLASH_MAX_CMDS_PER_LUN       CXLFLASH_MAX_CMDS
  53
  54 /* RRQ for master issued cmds */
  55 #define NUM_RRQ_ENTRY                   CXLFLASH_MAX_CMDS
  56
  57
  58 static inline void check_sizes(void)
  59 {
  60         BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_CMDS);
  61 }
  62
  63 /* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
  64 #define CMD_BUFSIZE     SIZE_4K
  65
  66 enum cxlflash_lr_state {
  67         LINK_RESET_INVALID,
  68         LINK_RESET_REQUIRED,
  69         LINK_RESET_COMPLETE
  70 };
  71
  72 enum cxlflash_init_state {
  73         INIT_STATE_NONE,
  74         INIT_STATE_PCI,
  75         INIT_STATE_AFU,
  76         INIT_STATE_SCSI
  77 };
  78
  79 enum cxlflash_state {
  80         STATE_NORMAL,   /* Normal running state, everything good */
  81         STATE_RESET,    /* Reset state, trying to reset/recover */
  82         STATE_FAILTERM  /* Failed/terminating state, error out users/threads */
  83 };
  84
  85 /*
  86  * Each context has its own set of resource handles that is visible
  87  * only from that context.
  88  */
  89
  90 struct cxlflash_cfg {
  91         struct afu *afu;
  92         struct cxl_context *mcctx;
  93
  94         struct pci_dev *dev;
  95         struct pci_device_id *dev_id;
  96         struct Scsi_Host *host;
  97
  98         ulong cxlflash_regs_pci;
  99
 100         struct work_struct work_q;
 101         enum cxlflash_init_state init_state;
 102         enum cxlflash_lr_state lr_state;
 103         int lr_port;
 104         atomic_t scan_host_needed;
 105
 106         struct cxl_afu *cxl_afu;
 107
 108         atomic_t recovery_threads;
 109         struct mutex ctx_recovery_mutex;
 110         struct mutex ctx_tbl_list_mutex;
 111         struct rw_semaphore ioctl_rwsem;
 112         struct ctx_info *ctx_tbl[MAX_CONTEXT];
 113         struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
 114         struct file_operations cxl_fops;
 115
 116         /* Parameters that are LUN table related */
 117         int last_lun_index[CXLFLASH_NUM_FC_PORTS];
 118         int promote_lun_index;
 119         struct list_head lluns; /* list of llun_info structs */
 120
 121         wait_queue_head_t tmf_waitq;
 122         spinlock_t tmf_slock;
 123         bool tmf_active;
 124         wait_queue_head_t reset_waitq;
 125         enum cxlflash_state state;
 126 };
 127
 128 struct afu_cmd {
 129         struct sisl_ioarcb rcb; /* IOARCB (cache line aligned) */
 130         struct sisl_ioasa sa;   /* IOASA must follow IOARCB */
 131         struct afu *parent;
 132         struct scsi_cmnd *scp;
 133         struct completion cevent;
 134
 135         u8 cmd_tmf:1;
 136
 137         /* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
 138          * However for performance reasons the IOARCB/IOASA should be
 139          * cache line aligned.
 140          */
 141 } __aligned(cache_line_size());
 142
 143 static inline struct afu_cmd *sc_to_afuc(struct scsi_cmnd *sc)
 144 {
 145         return PTR_ALIGN(scsi_cmd_priv(sc), __alignof__(struct afu_cmd));
 146 }
 147
 148 static inline struct afu_cmd *sc_to_afucz(struct scsi_cmnd *sc)
 149 {
 150         struct afu_cmd *afuc = sc_to_afuc(sc);
 151
 152         memset(afuc, 0, sizeof(*afuc));
 153         return afuc;
 154 }
 155
 156 struct afu {
 157         /* Stuff requiring alignment go first. */
 158
 159         u64 rrq_entry[NUM_RRQ_ENTRY];   /* 2K RRQ */
 160
 161         /* Beware of alignment till here. Preferably introduce new
 162          * fields after this point
 163          */
 164
 165         int (*send_cmd)(struct afu *, struct afu_cmd *);
 166         void (*context_reset)(struct afu_cmd *);
 167
 168         /* AFU HW */
 169         struct cxl_ioctl_start_work work;
 170         struct cxlflash_afu_map __iomem *afu_map;       /* entire MMIO map */
 171         struct sisl_host_map __iomem *host_map;         /* MC host map */
 172         struct sisl_ctrl_map __iomem *ctrl_map;         /* MC control map */
 173
 174         struct kref mapcount;
 175
 176         ctx_hndl_t ctx_hndl;    /* master's context handle */
 177         u64 *hrrq_start;
 178         u64 *hrrq_end;
 179         u64 *hrrq_curr;
 180         bool toggle;
 181         atomic_t cmds_active;   /* Number of currently active AFU commands */
 182         s64 room;
 183         spinlock_t rrin_slock; /* Lock to rrin queuing and cmd_room updates */
 184         u64 hb;
 185         u32 internal_lun;       /* User-desired LUN mode for this AFU */
 186
 187         char version[16];
 188         u64 interface_version;
 189
 190         struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
 191
 192 };
 193
 194 static inline u64 lun_to_lunid(u64 lun)
 195 {
 196         __be64 lun_id;
 197
 198         int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
 199         return be64_to_cpu(lun_id);
 200 }
 201
 202 int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8);
 203 void cxlflash_list_init(void);
 204 void cxlflash_term_global_luns(void);
 205 void cxlflash_free_errpage(void);
 206 int cxlflash_ioctl(struct scsi_device *, int, void __user *);
 207 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *);
 208 int cxlflash_mark_contexts_error(struct cxlflash_cfg *);
 209 void cxlflash_term_local_luns(struct cxlflash_cfg *);
 210 void cxlflash_restore_luntable(struct cxlflash_cfg *);
 211
 212 #endif /* ifndef _CXLFLASH_COMMON_H */