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/irq_poll.h>
  19 #include <linux/list.h>
  20 #include <linux/rwsem.h>
  21 #include <linux/types.h>
  22 #include <scsi/scsi.h>
  23 #include <scsi/scsi_cmnd.h>
  24 #include <scsi/scsi_device.h>
  25
  26 extern const struct file_operations cxlflash_cxl_fops;
  27
  28 #define MAX_CONTEXT  CXLFLASH_MAX_CONTEXT       /* num contexts per afu */
  29
  30 #define CXLFLASH_BLOCK_SIZE     4096    /* 4K blocks */
  31 #define CXLFLASH_MAX_XFER_SIZE  16777216        /* 16MB transfer */
  32 #define CXLFLASH_MAX_SECTORS    (CXLFLASH_MAX_XFER_SIZE/512)    /* SCSI wants
  33                                                                    max_sectors
  34                                                                    in units of
  35                                                                    512 byte
  36                                                                    sectors
  37                                                                 */
  38
  39 #define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry))
  40
  41 /* AFU command retry limit */
  42 #define MC_RETRY_CNT         5  /* sufficient for SCSI check and
  43                                    certain AFU errors */
  44
  45 /* Command management definitions */
  46 #define CXLFLASH_NUM_CMDS       (2 * CXLFLASH_MAX_CMDS) /* Must be a pow2 for
  47                                                            alignment and more
  48                                                            efficient array
  49                                                            index derivation
  50                                                          */
  51
  52 #define CXLFLASH_MAX_CMDS               256
  53 #define CXLFLASH_MAX_CMDS_PER_LUN       CXLFLASH_MAX_CMDS
  54
  55 /* RRQ for master issued cmds */
  56 #define NUM_RRQ_ENTRY                   CXLFLASH_MAX_CMDS
  57
  58 /* SQ for master issued cmds */
  59 #define NUM_SQ_ENTRY                    CXLFLASH_MAX_CMDS
  60
  61
  62 static inline void check_sizes(void)
  63 {
  64         BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_CMDS);
  65 }
  66
  67 /* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
  68 #define CMD_BUFSIZE     SIZE_4K
  69
  70 enum cxlflash_lr_state {
  71         LINK_RESET_INVALID,
  72         LINK_RESET_REQUIRED,
  73         LINK_RESET_COMPLETE
  74 };
  75
  76 enum cxlflash_init_state {
  77         INIT_STATE_NONE,
  78         INIT_STATE_PCI,
  79         INIT_STATE_AFU,
  80         INIT_STATE_SCSI
  81 };
  82
  83 enum cxlflash_state {
  84         STATE_NORMAL,   /* Normal running state, everything good */
  85         STATE_RESET,    /* Reset state, trying to reset/recover */
  86         STATE_FAILTERM  /* Failed/terminating state, error out users/threads */
  87 };
  88
  89 /*
  90  * Each context has its own set of resource handles that is visible
  91  * only from that context.
  92  */
  93
  94 struct cxlflash_cfg {
  95         struct afu *afu;
  96         struct cxl_context *mcctx;
  97
  98         struct pci_dev *dev;
  99         struct pci_device_id *dev_id;
 100         struct Scsi_Host *host;
 101
 102         ulong cxlflash_regs_pci;
 103
 104         struct work_struct work_q;
 105         enum cxlflash_init_state init_state;
 106         enum cxlflash_lr_state lr_state;
 107         int lr_port;
 108         atomic_t scan_host_needed;
 109
 110         struct cxl_afu *cxl_afu;
 111
 112         atomic_t recovery_threads;
 113         struct mutex ctx_recovery_mutex;
 114         struct mutex ctx_tbl_list_mutex;
 115         struct rw_semaphore ioctl_rwsem;
 116         struct ctx_info *ctx_tbl[MAX_CONTEXT];
 117         struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
 118         struct file_operations cxl_fops;
 119
 120         /* Parameters that are LUN table related */
 121         int last_lun_index[CXLFLASH_NUM_FC_PORTS];
 122         int promote_lun_index;
 123         struct list_head lluns; /* list of llun_info structs */
 124
 125         wait_queue_head_t tmf_waitq;
 126         spinlock_t tmf_slock;
 127         bool tmf_active;
 128         wait_queue_head_t reset_waitq;
 129         enum cxlflash_state state;
 130 };
 131
 132 struct afu_cmd {
 133         struct sisl_ioarcb rcb; /* IOARCB (cache line aligned) */
 134         struct sisl_ioasa sa;   /* IOASA must follow IOARCB */
 135         struct afu *parent;
 136         struct scsi_cmnd *scp;
 137         struct completion cevent;
 138         struct list_head queue;
 139
 140         u8 cmd_tmf:1;
 141
 142         /* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
 143          * However for performance reasons the IOARCB/IOASA should be
 144          * cache line aligned.
 145          */
 146 } __aligned(cache_line_size());
 147
 148 static inline struct afu_cmd *sc_to_afuc(struct scsi_cmnd *sc)
 149 {
 150         return PTR_ALIGN(scsi_cmd_priv(sc), __alignof__(struct afu_cmd));
 151 }
 152
 153 static inline struct afu_cmd *sc_to_afucz(struct scsi_cmnd *sc)
 154 {
 155         struct afu_cmd *afuc = sc_to_afuc(sc);
 156
 157         memset(afuc, 0, sizeof(*afuc));
 158         return afuc;
 159 }
 160
 161 struct afu {
 162         /* Stuff requiring alignment go first. */
 163         struct sisl_ioarcb sq[NUM_SQ_ENTRY];            /* 16K SQ */
 164         u64 rrq_entry[NUM_RRQ_ENTRY];                   /* 2K RRQ */
 165
 166         /* Beware of alignment till here. Preferably introduce new
 167          * fields after this point
 168          */
 169
 170         int (*send_cmd)(struct afu *, struct afu_cmd *);
 171         void (*context_reset)(struct afu_cmd *);
 172
 173         /* AFU HW */
 174         struct cxl_ioctl_start_work work;
 175         struct cxlflash_afu_map __iomem *afu_map;       /* entire MMIO map */
 176         struct sisl_host_map __iomem *host_map;         /* MC host map */
 177         struct sisl_ctrl_map __iomem *ctrl_map;         /* MC control map */
 178
 179         ctx_hndl_t ctx_hndl;    /* master's context handle */
 180
 181         atomic_t hsq_credits;
 182         spinlock_t hsq_slock;
 183         struct sisl_ioarcb *hsq_start;
 184         struct sisl_ioarcb *hsq_end;
 185         struct sisl_ioarcb *hsq_curr;
 186         spinlock_t hrrq_slock;
 187         u64 *hrrq_start;
 188         u64 *hrrq_end;
 189         u64 *hrrq_curr;
 190         bool toggle;
 191         atomic_t cmds_active;   /* Number of currently active AFU commands */
 192         s64 room;
 193         spinlock_t rrin_slock; /* Lock to rrin queuing and cmd_room updates */
 194         u64 hb;
 195         u32 internal_lun;       /* User-desired LUN mode for this AFU */
 196
 197         char version[16];
 198         u64 interface_version;
 199
 200         u32 irqpoll_weight;
 201         struct irq_poll irqpoll;
 202         struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
 203
 204 };
 205
 206 static inline bool afu_is_irqpoll_enabled(struct afu *afu)
 207 {
 208         return !!afu->irqpoll_weight;
 209 }
 210
 211 static inline bool afu_is_cmd_mode(struct afu *afu, u64 cmd_mode)
 212 {
 213         u64 afu_cap = afu->interface_version >> SISL_INTVER_CAP_SHIFT;
 214
 215         return afu_cap & cmd_mode;
 216 }
 217
 218 static inline bool afu_is_sq_cmd_mode(struct afu *afu)
 219 {
 220         return afu_is_cmd_mode(afu, SISL_INTVER_CAP_SQ_CMD_MODE);
 221 }
 222
 223 static inline bool afu_is_ioarrin_cmd_mode(struct afu *afu)
 224 {
 225         return afu_is_cmd_mode(afu, SISL_INTVER_CAP_IOARRIN_CMD_MODE);
 226 }
 227
 228 static inline u64 lun_to_lunid(u64 lun)
 229 {
 230         __be64 lun_id;
 231
 232         int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
 233         return be64_to_cpu(lun_id);
 234 }
 235
 236 int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8);
 237 void cxlflash_list_init(void);
 238 void cxlflash_term_global_luns(void);
 239 void cxlflash_free_errpage(void);
 240 int cxlflash_ioctl(struct scsi_device *, int, void __user *);
 241 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *);
 242 int cxlflash_mark_contexts_error(struct cxlflash_cfg *);
 243 void cxlflash_term_local_luns(struct cxlflash_cfg *);
 244 void cxlflash_restore_luntable(struct cxlflash_cfg *);
 245
 246 #endif /* ifndef _CXLFLASH_COMMON_H */