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