drivers/scsi/cxlflash/common.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * CXL Flash Device Driver
   4  *
   5  * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
   6  *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
   7  *
   8  * Copyright (C) 2015 IBM Corporation
   9  */
  10
  11 #ifndef _CXLFLASH_COMMON_H
  12 #define _CXLFLASH_COMMON_H
  13
  14 #include <linux/async.h>
  15 #include <linux/cdev.h>
  16 #include <linux/irq_poll.h>
  17 #include <linux/list.h>
  18 #include <linux/rwsem.h>
  19 #include <linux/types.h>
  20 #include <scsi/scsi.h>
  21 #include <scsi/scsi_cmnd.h>
  22 #include <scsi/scsi_device.h>
  23
  24 #include "backend.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 MAX_FC_PORTS    CXLFLASH_MAX_FC_PORTS   /* max ports per AFU */
  30 #define LEGACY_FC_PORTS 2                       /* legacy ports per AFU */
  31
  32 #define CHAN2PORTBANK(_x)       ((_x) >> ilog2(CXLFLASH_NUM_FC_PORTS_PER_BANK))
  33 #define CHAN2BANKPORT(_x)       ((_x) & (CXLFLASH_NUM_FC_PORTS_PER_BANK - 1))
  34
  35 #define CHAN2PORTMASK(_x)       (1 << (_x))     /* channel to port mask */
  36 #define PORTMASK2CHAN(_x)       (ilog2((_x)))   /* port mask to channel */
  37 #define PORTNUM2CHAN(_x)        ((_x) - 1)      /* port number to channel */
  38
  39 #define CXLFLASH_BLOCK_SIZE     4096            /* 4K blocks */
  40 #define CXLFLASH_MAX_XFER_SIZE  16777216        /* 16MB transfer */
  41 #define CXLFLASH_MAX_SECTORS    (CXLFLASH_MAX_XFER_SIZE/512)    /* SCSI wants
  42                                                                  * max_sectors
  43                                                                  * in units of
  44                                                                  * 512 byte
  45                                                                  * sectors
  46                                                                  */
  47
  48 #define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry))
  49
  50 /* AFU command retry limit */
  51 #define MC_RETRY_CNT    5       /* Sufficient for SCSI and certain AFU errors */
  52
  53 /* Command management definitions */
  54 #define CXLFLASH_MAX_CMDS               256
  55 #define CXLFLASH_MAX_CMDS_PER_LUN       CXLFLASH_MAX_CMDS
  56
  57 /* RRQ for master issued cmds */
  58 #define NUM_RRQ_ENTRY                   CXLFLASH_MAX_CMDS
  59
  60 /* SQ for master issued cmds */
  61 #define NUM_SQ_ENTRY                    CXLFLASH_MAX_CMDS
  62
  63 /* Hardware queue definitions */
  64 #define CXLFLASH_DEF_HWQS               1
  65 #define CXLFLASH_MAX_HWQS               8
  66 #define PRIMARY_HWQ                     0
  67
  68
  69 static inline void check_sizes(void)
  70 {
  71         BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_FC_PORTS_PER_BANK);
  72         BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_MAX_CMDS);
  73 }
  74
  75 /* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
  76 #define CMD_BUFSIZE     SIZE_4K
  77
  78 enum cxlflash_lr_state {
  79         LINK_RESET_INVALID,
  80         LINK_RESET_REQUIRED,
  81         LINK_RESET_COMPLETE
  82 };
  83
  84 enum cxlflash_init_state {
  85         INIT_STATE_NONE,
  86         INIT_STATE_PCI,
  87         INIT_STATE_AFU,
  88         INIT_STATE_SCSI,
  89         INIT_STATE_CDEV
  90 };
  91
  92 enum cxlflash_state {
  93         STATE_PROBING,  /* Initial state during probe */
  94         STATE_PROBED,   /* Temporary state, probe completed but EEH occurred */
  95         STATE_NORMAL,   /* Normal running state, everything good */
  96         STATE_RESET,    /* Reset state, trying to reset/recover */
  97         STATE_FAILTERM  /* Failed/terminating state, error out users/threads */
  98 };
  99
 100 enum cxlflash_hwq_mode {
 101         HWQ_MODE_RR,    /* Roundrobin (default) */
 102         HWQ_MODE_TAG,   /* Distribute based on block MQ tag */
 103         HWQ_MODE_CPU,   /* CPU affinity */
 104         MAX_HWQ_MODE
 105 };
 106
 107 /*
 108  * Each context has its own set of resource handles that is visible
 109  * only from that context.
 110  */
 111
 112 struct cxlflash_cfg {
 113         struct afu *afu;
 114
 115         const struct cxlflash_backend_ops *ops;
 116         struct pci_dev *dev;
 117         struct pci_device_id *dev_id;
 118         struct Scsi_Host *host;
 119         int num_fc_ports;
 120         struct cdev cdev;
 121         struct device *chardev;
 122
 123         ulong cxlflash_regs_pci;
 124
 125         struct work_struct work_q;
 126         enum cxlflash_init_state init_state;
 127         enum cxlflash_lr_state lr_state;
 128         int lr_port;
 129         atomic_t scan_host_needed;
 130
 131         void *afu_cookie;
 132
 133         atomic_t recovery_threads;
 134         struct mutex ctx_recovery_mutex;
 135         struct mutex ctx_tbl_list_mutex;
 136         struct rw_semaphore ioctl_rwsem;
 137         struct ctx_info *ctx_tbl[MAX_CONTEXT];
 138         struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
 139         struct file_operations cxl_fops;
 140
 141         /* Parameters that are LUN table related */
 142         int last_lun_index[MAX_FC_PORTS];
 143         int promote_lun_index;
 144         struct list_head lluns; /* list of llun_info structs */
 145
 146         wait_queue_head_t tmf_waitq;
 147         spinlock_t tmf_slock;
 148         bool tmf_active;
 149         bool ws_unmap;          /* Write-same unmap supported */
 150         wait_queue_head_t reset_waitq;
 151         enum cxlflash_state state;
 152         async_cookie_t async_reset_cookie;
 153 };
 154
 155 struct afu_cmd {
 156         struct sisl_ioarcb rcb; /* IOARCB (cache line aligned) */
 157         struct sisl_ioasa sa;   /* IOASA must follow IOARCB */
 158         struct afu *parent;
 159         struct scsi_cmnd *scp;
 160         struct completion cevent;
 161         struct list_head queue;
 162         u32 hwq_index;
 163
 164         u8 cmd_tmf:1,
 165            cmd_aborted:1;
 166
 167         struct list_head list;  /* Pending commands link */
 168
 169         /* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
 170          * However for performance reasons the IOARCB/IOASA should be
 171          * cache line aligned.
 172          */
 173 } __aligned(cache_line_size());
 174
 175 static inline struct afu_cmd *sc_to_afuc(struct scsi_cmnd *sc)
 176 {
 177         return PTR_ALIGN(scsi_cmd_priv(sc), __alignof__(struct afu_cmd));
 178 }
 179
 180 static inline struct afu_cmd *sc_to_afuci(struct scsi_cmnd *sc)
 181 {
 182         struct afu_cmd *afuc = sc_to_afuc(sc);
 183
 184         INIT_LIST_HEAD(&afuc->queue);
 185         return afuc;
 186 }
 187
 188 static inline struct afu_cmd *sc_to_afucz(struct scsi_cmnd *sc)
 189 {
 190         struct afu_cmd *afuc = sc_to_afuc(sc);
 191
 192         memset(afuc, 0, sizeof(*afuc));
 193         return sc_to_afuci(sc);
 194 }
 195
 196 struct hwq {
 197         /* Stuff requiring alignment go first. */
 198         struct sisl_ioarcb sq[NUM_SQ_ENTRY];            /* 16K SQ */
 199         u64 rrq_entry[NUM_RRQ_ENTRY];                   /* 2K RRQ */
 200
 201         /* Beware of alignment till here. Preferably introduce new
 202          * fields after this point
 203          */
 204         struct afu *afu;
 205         void *ctx_cookie;
 206         struct sisl_host_map __iomem *host_map;         /* MC host map */
 207         struct sisl_ctrl_map __iomem *ctrl_map;         /* MC control map */
 208         ctx_hndl_t ctx_hndl;    /* master's context handle */
 209         u32 index;              /* Index of this hwq */
 210         int num_irqs;           /* Number of interrupts requested for context */
 211         struct list_head pending_cmds;  /* Commands pending completion */
 212
 213         atomic_t hsq_credits;
 214         spinlock_t hsq_slock;   /* Hardware send queue lock */
 215         struct sisl_ioarcb *hsq_start;
 216         struct sisl_ioarcb *hsq_end;
 217         struct sisl_ioarcb *hsq_curr;
 218         spinlock_t hrrq_slock;
 219         u64 *hrrq_start;
 220         u64 *hrrq_end;
 221         u64 *hrrq_curr;
 222         bool toggle;
 223         bool hrrq_online;
 224
 225         s64 room;
 226
 227         struct irq_poll irqpoll;
 228 } __aligned(cache_line_size());
 229
 230 struct afu {
 231         struct hwq hwqs[CXLFLASH_MAX_HWQS];
 232         int (*send_cmd)(struct afu *afu, struct afu_cmd *cmd);
 233         int (*context_reset)(struct hwq *hwq);
 234
 235         /* AFU HW */
 236         struct cxlflash_afu_map __iomem *afu_map;       /* entire MMIO map */
 237
 238         atomic_t cmds_active;   /* Number of currently active AFU commands */
 239         struct mutex sync_active;       /* Mutex to serialize AFU commands */
 240         u64 hb;
 241         u32 internal_lun;       /* User-desired LUN mode for this AFU */
 242
 243         u32 num_hwqs;           /* Number of hardware queues */
 244         u32 desired_hwqs;       /* Desired h/w queues, effective on AFU reset */
 245         enum cxlflash_hwq_mode hwq_mode; /* Steering mode for h/w queues */
 246         u32 hwq_rr_count;       /* Count to distribute traffic for roundrobin */
 247
 248         char version[16];
 249         u64 interface_version;
 250
 251         u32 irqpoll_weight;
 252         struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
 253 };
 254
 255 static inline struct hwq *get_hwq(struct afu *afu, u32 index)
 256 {
 257         WARN_ON(index >= CXLFLASH_MAX_HWQS);
 258
 259         return &afu->hwqs[index];
 260 }
 261
 262 static inline bool afu_is_irqpoll_enabled(struct afu *afu)
 263 {
 264         return !!afu->irqpoll_weight;
 265 }
 266
 267 static inline bool afu_has_cap(struct afu *afu, u64 cap)
 268 {
 269         u64 afu_cap = afu->interface_version >> SISL_INTVER_CAP_SHIFT;
 270
 271         return afu_cap & cap;
 272 }
 273
 274 static inline bool afu_is_ocxl_lisn(struct afu *afu)
 275 {
 276         return afu_has_cap(afu, SISL_INTVER_CAP_OCXL_LISN);
 277 }
 278
 279 static inline bool afu_is_afu_debug(struct afu *afu)
 280 {
 281         return afu_has_cap(afu, SISL_INTVER_CAP_AFU_DEBUG);
 282 }
 283
 284 static inline bool afu_is_lun_provision(struct afu *afu)
 285 {
 286         return afu_has_cap(afu, SISL_INTVER_CAP_LUN_PROVISION);
 287 }
 288
 289 static inline bool afu_is_sq_cmd_mode(struct afu *afu)
 290 {
 291         return afu_has_cap(afu, SISL_INTVER_CAP_SQ_CMD_MODE);
 292 }
 293
 294 static inline bool afu_is_ioarrin_cmd_mode(struct afu *afu)
 295 {
 296         return afu_has_cap(afu, SISL_INTVER_CAP_IOARRIN_CMD_MODE);
 297 }
 298
 299 static inline u64 lun_to_lunid(u64 lun)
 300 {
 301         __be64 lun_id;
 302
 303         int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
 304         return be64_to_cpu(lun_id);
 305 }
 306
 307 static inline struct fc_port_bank __iomem *get_fc_port_bank(
 308                                             struct cxlflash_cfg *cfg, int i)
 309 {
 310         struct afu *afu = cfg->afu;
 311
 312         return &afu->afu_map->global.bank[CHAN2PORTBANK(i)];
 313 }
 314
 315 static inline __be64 __iomem *get_fc_port_regs(struct cxlflash_cfg *cfg, int i)
 316 {
 317         struct fc_port_bank __iomem *fcpb = get_fc_port_bank(cfg, i);
 318
 319         return &fcpb->fc_port_regs[CHAN2BANKPORT(i)][0];
 320 }
 321
 322 static inline __be64 __iomem *get_fc_port_luns(struct cxlflash_cfg *cfg, int i)
 323 {
 324         struct fc_port_bank __iomem *fcpb = get_fc_port_bank(cfg, i);
 325
 326         return &fcpb->fc_port_luns[CHAN2BANKPORT(i)][0];
 327 }
 328
 329 int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t c, res_hndl_t r, u8 mode);
 330 void cxlflash_list_init(void);
 331 void cxlflash_term_global_luns(void);
 332 void cxlflash_free_errpage(void);
 333 int cxlflash_ioctl(struct scsi_device *sdev, unsigned int cmd,
 334                    void __user *arg);
 335 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *cfg);
 336 int cxlflash_mark_contexts_error(struct cxlflash_cfg *cfg);
 337 void cxlflash_term_local_luns(struct cxlflash_cfg *cfg);
 338 void cxlflash_restore_luntable(struct cxlflash_cfg *cfg);
 339
 340 #endif /* ifndef _CXLFLASH_COMMON_H */