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