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 cxlflash_cfg *cfg = shost_priv(sdev->host);
  36         struct device *dev = &cfg->dev->dev;
  37         struct llun_info *lli = NULL;
  38
  39         lli = kzalloc(sizeof(*lli), GFP_KERNEL);
  40         if (unlikely(!lli)) {
  41                 dev_err(dev, "%s: could not allocate lli\n", __func__);
  42                 goto out;
  43         }
  44
  45         lli->sdev = sdev;
  46         lli->host_no = sdev->host->host_no;
  47         lli->in_table = false;
  48
  49         memcpy(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN);
  50 out:
  51         return lli;
  52 }
  53
  54 /**
  55  * create_global() - allocate and initialize a global LUN information structure
  56  * @sdev:       SCSI device associated with LUN.
  57  * @wwid:       World Wide Node Name for LUN.
  58  *
  59  * Return: Allocated global glun_info structure on success, NULL on failure
  60  */
  61 static struct glun_info *create_global(struct scsi_device *sdev, u8 *wwid)
  62 {
  63         struct cxlflash_cfg *cfg = shost_priv(sdev->host);
  64         struct device *dev = &cfg->dev->dev;
  65         struct glun_info *gli = NULL;
  66
  67         gli = kzalloc(sizeof(*gli), GFP_KERNEL);
  68         if (unlikely(!gli)) {
  69                 dev_err(dev, "%s: could not allocate gli\n", __func__);
  70                 goto out;
  71         }
  72
  73         mutex_init(&gli->mutex);
  74         memcpy(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN);
  75 out:
  76         return gli;
  77 }
  78
  79 /**
  80  * lookup_local() - find a local LUN information structure by WWID
  81  * @cfg:        Internal structure associated with the host.
  82  * @wwid:       WWID associated with LUN.
  83  *
  84  * Return: Found local lun_info structure on success, NULL on failure
  85  */
  86 static struct llun_info *lookup_local(struct cxlflash_cfg *cfg, u8 *wwid)
  87 {
  88         struct llun_info *lli, *temp;
  89
  90         list_for_each_entry_safe(lli, temp, &cfg->lluns, list)
  91                 if (!memcmp(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN))
  92                         return lli;
  93
  94         return NULL;
  95 }
  96
  97 /**
  98  * lookup_global() - find a global LUN information structure by WWID
  99  * @wwid:       WWID associated with LUN.
 100  *
 101  * Return: Found global lun_info structure on success, NULL on failure
 102  */
 103 static struct glun_info *lookup_global(u8 *wwid)
 104 {
 105         struct glun_info *gli, *temp;
 106
 107         list_for_each_entry_safe(gli, temp, &global.gluns, list)
 108                 if (!memcmp(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN))
 109                         return gli;
 110
 111         return NULL;
 112 }
 113
 114 /**
 115  * find_and_create_lun() - find or create a local LUN information structure
 116  * @sdev:       SCSI device associated with LUN.
 117  * @wwid:       WWID associated with LUN.
 118  *
 119  * The LUN is kept both in a local list (per adapter) and in a global list
 120  * (across all adapters). Certain attributes of the LUN are local to the
 121  * adapter (such as index, port selection mask, etc.).
 122  *
 123  * The block allocation map is shared across all adapters (i.e. associated
 124  * wih the global list). Since different attributes are associated with
 125  * the per adapter and global entries, allocate two separate structures for each
 126  * LUN (one local, one global).
 127  *
 128  * Keep a pointer back from the local to the global entry.
 129  *
 130  * This routine assumes the caller holds the global mutex.
 131  *
 132  * Return: Found/Allocated local lun_info structure on success, NULL on failure
 133  */
 134 static struct llun_info *find_and_create_lun(struct scsi_device *sdev, u8 *wwid)
 135 {
 136         struct cxlflash_cfg *cfg = shost_priv(sdev->host);
 137         struct device *dev = &cfg->dev->dev;
 138         struct llun_info *lli = NULL;
 139         struct glun_info *gli = NULL;
 140
 141         if (unlikely(!wwid))
 142                 goto out;
 143
 144         lli = lookup_local(cfg, wwid);
 145         if (lli)
 146                 goto out;
 147
 148         lli = create_local(sdev, wwid);
 149         if (unlikely(!lli))
 150                 goto out;
 151
 152         gli = lookup_global(wwid);
 153         if (gli) {
 154                 lli->parent = gli;
 155                 list_add(&lli->list, &cfg->lluns);
 156                 goto out;
 157         }
 158
 159         gli = create_global(sdev, wwid);
 160         if (unlikely(!gli)) {
 161                 kfree(lli);
 162                 lli = NULL;
 163                 goto out;
 164         }
 165
 166         lli->parent = gli;
 167         list_add(&lli->list, &cfg->lluns);
 168
 169         list_add(&gli->list, &global.gluns);
 170
 171 out:
 172         dev_dbg(dev, "%s: returning lli=%p, gli=%p\n", __func__, lli, gli);
 173         return lli;
 174 }
 175
 176 /**
 177  * cxlflash_term_local_luns() - Delete all entries from local LUN list, free.
 178  * @cfg:        Internal structure associated with the host.
 179  */
 180 void cxlflash_term_local_luns(struct cxlflash_cfg *cfg)
 181 {
 182         struct llun_info *lli, *temp;
 183
 184         mutex_lock(&global.mutex);
 185         list_for_each_entry_safe(lli, temp, &cfg->lluns, list) {
 186                 list_del(&lli->list);
 187                 kfree(lli);
 188         }
 189         mutex_unlock(&global.mutex);
 190 }
 191
 192 /**
 193  * cxlflash_list_init() - initializes the global LUN list
 194  */
 195 void cxlflash_list_init(void)
 196 {
 197         INIT_LIST_HEAD(&global.gluns);
 198         mutex_init(&global.mutex);
 199         global.err_page = NULL;
 200 }
 201
 202 /**
 203  * cxlflash_term_global_luns() - frees resources associated with global LUN list
 204  */
 205 void cxlflash_term_global_luns(void)
 206 {
 207         struct glun_info *gli, *temp;
 208
 209         mutex_lock(&global.mutex);
 210         list_for_each_entry_safe(gli, temp, &global.gluns, list) {
 211                 list_del(&gli->list);
 212                 cxlflash_ba_terminate(&gli->blka.ba_lun);
 213                 kfree(gli);
 214         }
 215         mutex_unlock(&global.mutex);
 216 }
 217
 218 /**
 219  * cxlflash_manage_lun() - handles LUN management activities
 220  * @sdev:       SCSI device associated with LUN.
 221  * @manage:     Manage ioctl data structure.
 222  *
 223  * This routine is used to notify the driver about a LUN's WWID and associate
 224  * SCSI devices (sdev) with a global LUN instance. Additionally it serves to
 225  * change a LUN's operating mode: legacy or superpipe.
 226  *
 227  * Return: 0 on success, -errno on failure
 228  */
 229 int cxlflash_manage_lun(struct scsi_device *sdev,
 230                         struct dk_cxlflash_manage_lun *manage)
 231 {
 232         struct cxlflash_cfg *cfg = shost_priv(sdev->host);
 233         struct device *dev = &cfg->dev->dev;
 234         struct llun_info *lli = NULL;
 235         int rc = 0;
 236         u64 flags = manage->hdr.flags;
 237         u32 chan = sdev->channel;
 238
 239         mutex_lock(&global.mutex);
 240         lli = find_and_create_lun(sdev, manage->wwid);
 241         dev_dbg(dev, "%s: WWID=%016llx%016llx, flags=%016llx lli=%p\n",
 242                 __func__, get_unaligned_be64(&manage->wwid[0]),
 243                 get_unaligned_be64(&manage->wwid[8]), manage->hdr.flags, lli);
 244         if (unlikely(!lli)) {
 245                 rc = -ENOMEM;
 246                 goto out;
 247         }
 248
 249         if (flags & DK_CXLFLASH_MANAGE_LUN_ENABLE_SUPERPIPE) {
 250                 /*
 251                  * Update port selection mask based upon channel, store off LUN
 252                  * in unpacked, AFU-friendly format, and hang LUN reference in
 253                  * the sdev.
 254                  */
 255                 lli->port_sel |= CHAN2PORT(chan);
 256                 lli->lun_id[chan] = lun_to_lunid(sdev->lun);
 257                 sdev->hostdata = lli;
 258         } else if (flags & DK_CXLFLASH_MANAGE_LUN_DISABLE_SUPERPIPE) {
 259                 if (lli->parent->mode != MODE_NONE)
 260                         rc = -EBUSY;
 261                 else {
 262                         /*
 263                          * Clean up local LUN for this port and reset table
 264                          * tracking when no more references exist.
 265                          */
 266                         sdev->hostdata = NULL;
 267                         lli->port_sel &= ~CHAN2PORT(chan);
 268                         if (lli->port_sel == 0U)
 269                                 lli->in_table = false;
 270                 }
 271         }
 272
 273         dev_dbg(dev, "%s: port_sel=%08x chan=%u lun_id=%016llx\n",
 274                 __func__, lli->port_sel, chan, lli->lun_id[chan]);
 275
 276 out:
 277         mutex_unlock(&global.mutex);
 278         dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
 279         return rc;
 280 }