drivers/scsi/cxlflash/lunmgt.c

   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 #include <misc/cxl.h>
  16 #include <asm/unaligned.h>
  17
  18 #include <scsi/scsi_host.h>
  19 #include <uapi/scsi/cxlflash_ioctl.h>
  20
  21 #include "sislite.h"
  22 #include "common.h"
  23 #include "vlun.h"
  24 #include "superpipe.h"
  25
  26 /**
  27  * create_local() - allocate and initialize a local LUN information structure
  28  * @sdev:       SCSI device associated with LUN.
  29  * @wwid:       World Wide Node Name for LUN.
  30  *
  31  * Return: Allocated local llun_info structure on success, NULL on failure
  32  */
  33 static struct llun_info *create_local(struct scsi_device *sdev, u8 *wwid)
  34 {
  35         struct llun_info *lli = NULL;
  36
  37         lli = kzalloc(sizeof(*lli), GFP_KERNEL);
  38         if (unlikely(!lli)) {
  39                 pr_err("%s: could not allocate lli\n", __func__);
  40                 goto out;
  41         }
  42
  43         lli->sdev = sdev;
  44         lli->host_no = sdev->host->host_no;
  45         lli->in_table = false;
  46
  47         memcpy(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN);
  48 out:
  49         return lli;
  50 }
  51
  52 /**
  53  * create_global() - allocate and initialize a global LUN information structure
  54  * @sdev:       SCSI device associated with LUN.
  55  * @wwid:       World Wide Node Name for LUN.
  56  *
  57  * Return: Allocated global glun_info structure on success, NULL on failure
  58  */
  59 static struct glun_info *create_global(struct scsi_device *sdev, u8 *wwid)
  60 {
  61         struct glun_info *gli = NULL;
  62
  63         gli = kzalloc(sizeof(*gli), GFP_KERNEL);
  64         if (unlikely(!gli)) {
  65                 pr_err("%s: could not allocate gli\n", __func__);
  66                 goto out;
  67         }
  68
  69         mutex_init(&gli->mutex);
  70         memcpy(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN);
  71 out:
  72         return gli;
  73 }
  74
  75 /**
  76  * lookup_local() - find a local LUN information structure by WWID
  77  * @cfg:        Internal structure associated with the host.
  78  * @wwid:       WWID associated with LUN.
  79  *
  80  * Return: Found local lun_info structure on success, NULL on failure
  81  */
  82 static struct llun_info *lookup_local(struct cxlflash_cfg *cfg, u8 *wwid)
  83 {
  84         struct llun_info *lli, *temp;
  85
  86         list_for_each_entry_safe(lli, temp, &cfg->lluns, list)
  87                 if (!memcmp(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN))
  88                         return lli;
  89
  90         return NULL;
  91 }
  92
  93 /**
  94  * lookup_global() - find a global LUN information structure by WWID
  95  * @wwid:       WWID associated with LUN.
  96  *
  97  * Return: Found global lun_info structure on success, NULL on failure
  98  */
  99 static struct glun_info *lookup_global(u8 *wwid)
 100 {
 101         struct glun_info *gli, *temp;
 102
 103         list_for_each_entry_safe(gli, temp, &global.gluns, list)
 104                 if (!memcmp(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN))
 105                         return gli;
 106
 107         return NULL;
 108 }
 109
 110 /**
 111  * find_and_create_lun() - find or create a local LUN information structure
 112  * @sdev:       SCSI device associated with LUN.
 113  * @wwid:       WWID associated with LUN.
 114  *
 115  * The LUN is kept both in a local list (per adapter) and in a global list
 116  * (across all adapters). Certain attributes of the LUN are local to the
 117  * adapter (such as index, port selection mask, etc.).
 118  *
 119  * The block allocation map is shared across all adapters (i.e. associated
 120  * wih the global list). Since different attributes are associated with
 121  * the per adapter and global entries, allocate two separate structures for each
 122  * LUN (one local, one global).
 123  *
 124  * Keep a pointer back from the local to the global entry.
 125  *
 126  * This routine assumes the caller holds the global mutex.
 127  *
 128  * Return: Found/Allocated local lun_info structure on success, NULL on failure
 129  */
 130 static struct llun_info *find_and_create_lun(struct scsi_device *sdev, u8 *wwid)
 131 {
 132         struct llun_info *lli = NULL;
 133         struct glun_info *gli = NULL;
 134         struct Scsi_Host *shost = sdev->host;
 135         struct cxlflash_cfg *cfg = shost_priv(shost);
 136
 137         if (unlikely(!wwid))
 138                 goto out;
 139
 140         lli = lookup_local(cfg, wwid);
 141         if (lli)
 142                 goto out;
 143
 144         lli = create_local(sdev, wwid);
 145         if (unlikely(!lli))
 146                 goto out;
 147
 148         gli = lookup_global(wwid);
 149         if (gli) {
 150                 lli->parent = gli;
 151                 list_add(&lli->list, &cfg->lluns);
 152                 goto out;
 153         }
 154
 155         gli = create_global(sdev, wwid);
 156         if (unlikely(!gli)) {
 157                 kfree(lli);
 158                 lli = NULL;
 159                 goto out;
 160         }
 161
 162         lli->parent = gli;
 163         list_add(&lli->list, &cfg->lluns);
 164
 165         list_add(&gli->list, &global.gluns);
 166
 167 out:
 168         pr_debug("%s: returning %p\n", __func__, lli);
 169         return lli;
 170 }
 171
 172 /**
 173  * cxlflash_term_local_luns() - Delete all entries from local LUN list, free.
 174  * @cfg:        Internal structure associated with the host.
 175  */
 176 void cxlflash_term_local_luns(struct cxlflash_cfg *cfg)
 177 {
 178         struct llun_info *lli, *temp;
 179
 180         mutex_lock(&global.mutex);
 181         list_for_each_entry_safe(lli, temp, &cfg->lluns, list) {
 182                 list_del(&lli->list);
 183                 kfree(lli);
 184         }
 185         mutex_unlock(&global.mutex);
 186 }
 187
 188 /**
 189  * cxlflash_list_init() - initializes the global LUN list
 190  */
 191 void cxlflash_list_init(void)
 192 {
 193         INIT_LIST_HEAD(&global.gluns);
 194         mutex_init(&global.mutex);
 195         global.err_page = NULL;
 196 }
 197
 198 /**
 199  * cxlflash_term_global_luns() - frees resources associated with global LUN list
 200  */
 201 void cxlflash_term_global_luns(void)
 202 {
 203         struct glun_info *gli, *temp;
 204
 205         mutex_lock(&global.mutex);
 206         list_for_each_entry_safe(gli, temp, &global.gluns, list) {
 207                 list_del(&gli->list);
 208                 cxlflash_ba_terminate(&gli->blka.ba_lun);
 209                 kfree(gli);
 210         }
 211         mutex_unlock(&global.mutex);
 212 }
 213
 214 /**
 215  * cxlflash_manage_lun() - handles LUN management activities
 216  * @sdev:       SCSI device associated with LUN.
 217  * @manage:     Manage ioctl data structure.
 218  *
 219  * This routine is used to notify the driver about a LUN's WWID and associate
 220  * SCSI devices (sdev) with a global LUN instance. Additionally it serves to
 221  * change a LUN's operating mode: legacy or superpipe.
 222  *
 223  * Return: 0 on success, -errno on failure
 224  */
 225 int cxlflash_manage_lun(struct scsi_device *sdev,
 226                         struct dk_cxlflash_manage_lun *manage)
 227 {
 228         int rc = 0;
 229         struct llun_info *lli = NULL;
 230         u64 flags = manage->hdr.flags;
 231         u32 chan = sdev->channel;
 232
 233         mutex_lock(&global.mutex);
 234         lli = find_and_create_lun(sdev, manage->wwid);
 235         pr_debug("%s: ENTER: WWID = %016llX%016llX, flags = %016llX li = %p\n",
 236                  __func__, get_unaligned_be64(&manage->wwid[0]),
 237                  get_unaligned_be64(&manage->wwid[8]),
 238                  manage->hdr.flags, lli);
 239         if (unlikely(!lli)) {
 240                 rc = -ENOMEM;
 241                 goto out;
 242         }
 243
 244         if (flags & DK_CXLFLASH_MANAGE_LUN_ENABLE_SUPERPIPE) {
 245                 /*
 246                  * Update port selection mask based upon channel, store off LUN
 247                  * in unpacked, AFU-friendly format, and hang LUN reference in
 248                  * the sdev.
 249                  */
 250                 lli->port_sel |= CHAN2PORT(chan);
 251                 lli->lun_id[chan] = lun_to_lunid(sdev->lun);
 252                 sdev->hostdata = lli;
 253         } else if (flags & DK_CXLFLASH_MANAGE_LUN_DISABLE_SUPERPIPE) {
 254                 if (lli->parent->mode != MODE_NONE)
 255                         rc = -EBUSY;
 256                 else {
 257                         sdev->hostdata = NULL;
 258                         lli->port_sel &= ~CHAN2PORT(chan);
 259                 }
 260         }
 261
 262         pr_debug("%s: port_sel = %08X chan = %u lun_id = %016llX\n", __func__,
 263                  lli->port_sel, chan, lli->lun_id[chan]);
 264
 265 out:
 266         mutex_unlock(&global.mutex);
 267         pr_debug("%s: returning rc=%d\n", __func__, rc);
 268         return rc;
 269 }