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 #define NUM_FC_PORTS    CXLFLASH_NUM_FC_PORTS   /* ports per AFU */
  30 #define MAX_FC_PORTS    CXLFLASH_MAX_FC_PORTS   /* ports per AFU */
  31
  32 #define CHAN2PORTMASK(_x)       (1 << (_x))     /* channel to port mask */
  33 #define PORTMASK2CHAN(_x)       (ilog2((_x)))   /* port mask to channel */
  34 #define PORTNUM2CHAN(_x)        ((_x) - 1)      /* port number to channel */
  35
  36 #define CXLFLASH_BLOCK_SIZE     4096    /* 4K blocks */
  37 #define CXLFLASH_MAX_XFER_SIZE  16777216        /* 16MB transfer */
  38 #define CXLFLASH_MAX_SECTORS    (CXLFLASH_MAX_XFER_SIZE/512)    /* SCSI wants
  39                                                                    max_sectors
  40                                                                    in units of
  41                                                                    512 byte
  42                                                                    sectors
  43                                                                 */
  44
  45 #define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry))
  46
  47 /* AFU command retry limit */
  48 #define MC_RETRY_CNT         5  /* sufficient for SCSI check and
  49                                    certain AFU errors */
  50
  51 /* Command management definitions */
  52 #define CXLFLASH_NUM_CMDS       (2 * CXLFLASH_MAX_CMDS) /* Must be a pow2 for
  53                                                            alignment and more
  54                                                            efficient array
  55                                                            index derivation
  56                                                          */
  57
  58 #define CXLFLASH_MAX_CMDS               256
  59 #define CXLFLASH_MAX_CMDS_PER_LUN       CXLFLASH_MAX_CMDS
  60
  61 /* RRQ for master issued cmds */
  62 #define NUM_RRQ_ENTRY                   CXLFLASH_MAX_CMDS
  63
  64 /* SQ for master issued cmds */
  65 #define NUM_SQ_ENTRY                    CXLFLASH_MAX_CMDS
  66
  67
  68 static inline void check_sizes(void)
  69 {
  70         BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_CMDS);
  71 }
  72
  73 /* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
  74 #define CMD_BUFSIZE     SIZE_4K
  75
  76 enum cxlflash_lr_state {
  77         LINK_RESET_INVALID,
  78         LINK_RESET_REQUIRED,
  79         LINK_RESET_COMPLETE
  80 };
  81
  82 enum cxlflash_init_state {
  83         INIT_STATE_NONE,
  84         INIT_STATE_PCI,
  85         INIT_STATE_AFU,
  86         INIT_STATE_SCSI
  87 };
  88
  89 enum cxlflash_state {
  90         STATE_NORMAL,   /* Normal running state, everything good */
  91         STATE_RESET,    /* Reset state, trying to reset/recover */
  92         STATE_FAILTERM  /* Failed/terminating state, error out users/threads */
  93 };
  94
  95 /*
  96  * Each context has its own set of resource handles that is visible
  97  * only from that context.
  98  */
  99
 100 struct cxlflash_cfg {
 101         struct afu *afu;
 102         struct cxl_context *mcctx;
 103
 104         struct pci_dev *dev;
 105         struct pci_device_id *dev_id;
 106         struct Scsi_Host *host;
 107         int num_fc_ports;
 108
 109         ulong cxlflash_regs_pci;
 110
 111         struct work_struct work_q;
 112         enum cxlflash_init_state init_state;
 113         enum cxlflash_lr_state lr_state;
 114         int lr_port;
 115         atomic_t scan_host_needed;
 116
 117         struct cxl_afu *cxl_afu;
 118
 119         atomic_t recovery_threads;
 120         struct mutex ctx_recovery_mutex;
 121         struct mutex ctx_tbl_list_mutex;
 122         struct rw_semaphore ioctl_rwsem;
 123         struct ctx_info *ctx_tbl[MAX_CONTEXT];
 124         struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
 125         struct file_operations cxl_fops;
 126
 127         /* Parameters that are LUN table related */
 128         int last_lun_index[MAX_FC_PORTS];
 129         int promote_lun_index;
 130         struct list_head lluns; /* list of llun_info structs */
 131
 132         wait_queue_head_t tmf_waitq;
 133         spinlock_t tmf_slock;
 134         bool tmf_active;
 135         wait_queue_head_t reset_waitq;
 136         enum cxlflash_state state;
 137 };
 138
 139 struct afu_cmd {
 140         struct sisl_ioarcb rcb; /* IOARCB (cache line aligned) */
 141         struct sisl_ioasa sa;   /* IOASA must follow IOARCB */
 142         struct afu *parent;
 143         struct scsi_cmnd *scp;
 144         struct completion cevent;
 145         struct list_head queue;
 146
 147         u8 cmd_tmf:1;
 148
 149         /* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
 150          * However for performance reasons the IOARCB/IOASA should be
 151          * cache line aligned.
 152          */
 153 } __aligned(cache_line_size());
 154
 155 static inline struct afu_cmd *sc_to_afuc(struct scsi_cmnd *sc)
 156 {
 157         return PTR_ALIGN(scsi_cmd_priv(sc), __alignof__(struct afu_cmd));
 158 }
 159
 160 static inline struct afu_cmd *sc_to_afucz(struct scsi_cmnd *sc)
 161 {
 162         struct afu_cmd *afuc = sc_to_afuc(sc);
 163
 164         memset(afuc, 0, sizeof(*afuc));
 165         return afuc;
 166 }
 167
 168 struct afu {
 169         /* Stuff requiring alignment go first. */
 170         struct sisl_ioarcb sq[NUM_SQ_ENTRY];            /* 16K SQ */
 171         u64 rrq_entry[NUM_RRQ_ENTRY];                   /* 2K RRQ */
 172
 173         /* Beware of alignment till here. Preferably introduce new
 174          * fields after this point
 175          */
 176
 177         int (*send_cmd)(struct afu *, struct afu_cmd *);
 178         void (*context_reset)(struct afu_cmd *);
 179
 180         /* AFU HW */
 181         struct cxl_ioctl_start_work work;
 182         struct cxlflash_afu_map __iomem *afu_map;       /* entire MMIO map */
 183         struct sisl_host_map __iomem *host_map;         /* MC host map */
 184         struct sisl_ctrl_map __iomem *ctrl_map;         /* MC control map */
 185
 186         ctx_hndl_t ctx_hndl;    /* master's context handle */
 187
 188         atomic_t hsq_credits;
 189         spinlock_t hsq_slock;
 190         struct sisl_ioarcb *hsq_start;
 191         struct sisl_ioarcb *hsq_end;
 192         struct sisl_ioarcb *hsq_curr;
 193         spinlock_t hrrq_slock;
 194         u64 *hrrq_start;
 195         u64 *hrrq_end;
 196         u64 *hrrq_curr;
 197         bool toggle;
 198         atomic_t cmds_active;   /* Number of currently active AFU commands */
 199         s64 room;
 200         spinlock_t rrin_slock; /* Lock to rrin queuing and cmd_room updates */
 201         u64 hb;
 202         u32 internal_lun;       /* User-desired LUN mode for this AFU */
 203
 204         char version[16];
 205         u64 interface_version;
 206
 207         u32 irqpoll_weight;
 208         struct irq_poll irqpoll;
 209         struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
 210
 211 };
 212
 213 static inline bool afu_is_irqpoll_enabled(struct afu *afu)
 214 {
 215         return !!afu->irqpoll_weight;
 216 }
 217
 218 static inline bool afu_is_cmd_mode(struct afu *afu, u64 cmd_mode)
 219 {
 220         u64 afu_cap = afu->interface_version >> SISL_INTVER_CAP_SHIFT;
 221
 222         return afu_cap & cmd_mode;
 223 }
 224
 225 static inline bool afu_is_sq_cmd_mode(struct afu *afu)
 226 {
 227         return afu_is_cmd_mode(afu, SISL_INTVER_CAP_SQ_CMD_MODE);
 228 }
 229
 230 static inline bool afu_is_ioarrin_cmd_mode(struct afu *afu)
 231 {
 232         return afu_is_cmd_mode(afu, SISL_INTVER_CAP_IOARRIN_CMD_MODE);
 233 }
 234
 235 static inline u64 lun_to_lunid(u64 lun)
 236 {
 237         __be64 lun_id;
 238
 239         int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
 240         return be64_to_cpu(lun_id);
 241 }
 242
 243 int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8);
 244 void cxlflash_list_init(void);
 245 void cxlflash_term_global_luns(void);
 246 void cxlflash_free_errpage(void);
 247 int cxlflash_ioctl(struct scsi_device *, int, void __user *);
 248 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *);
 249 int cxlflash_mark_contexts_error(struct cxlflash_cfg *);
 250 void cxlflash_term_local_luns(struct cxlflash_cfg *);
 251 void cxlflash_restore_luntable(struct cxlflash_cfg *);
 252
 253 #endif /* ifndef _CXLFLASH_COMMON_H */