root/drivers/nvdimm/badrange.c

DEFINITIONS

1. badrange_init
2. append_badrange_entry
3. alloc_and_append_badrange_entry
4. add_badrange
5. badrange_add
6. badrange_forget
7. set_badblock
8. __add_badblock_range
9. badblocks_populate
10. nvdimm_badblocks_populate

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright(c) 2017 Intel Corporation. All rights reserved.
   4  */
   5 #include <linux/libnvdimm.h>
   6 #include <linux/badblocks.h>
   7 #include <linux/export.h>
   8 #include <linux/module.h>
   9 #include <linux/blkdev.h>
  10 #include <linux/device.h>
  11 #include <linux/ctype.h>
  12 #include <linux/ndctl.h>
  13 #include <linux/mutex.h>
  14 #include <linux/slab.h>
  15 #include <linux/io.h>
  16 #include "nd-core.h"
  17 #include "nd.h"
  18 
  19 void badrange_init(struct badrange *badrange)
  20 {
  21         INIT_LIST_HEAD(&badrange->list);
  22         spin_lock_init(&badrange->lock);
  23 }
  24 EXPORT_SYMBOL_GPL(badrange_init);
  25 
  26 static void append_badrange_entry(struct badrange *badrange,
  27                 struct badrange_entry *bre, u64 addr, u64 length)
  28 {
  29         lockdep_assert_held(&badrange->lock);
  30         bre->start = addr;
  31         bre->length = length;
  32         list_add_tail(&bre->list, &badrange->list);
  33 }
  34 
  35 static int alloc_and_append_badrange_entry(struct badrange *badrange,
  36                 u64 addr, u64 length, gfp_t flags)
  37 {
  38         struct badrange_entry *bre;
  39 
  40         bre = kzalloc(sizeof(*bre), flags);
  41         if (!bre)
  42                 return -ENOMEM;
  43 
  44         append_badrange_entry(badrange, bre, addr, length);
  45         return 0;
  46 }
  47 
  48 static int add_badrange(struct badrange *badrange, u64 addr, u64 length)
  49 {
  50         struct badrange_entry *bre, *bre_new;
  51 
  52         spin_unlock(&badrange->lock);
  53         bre_new = kzalloc(sizeof(*bre_new), GFP_KERNEL);
  54         spin_lock(&badrange->lock);
  55 
  56         if (list_empty(&badrange->list)) {
  57                 if (!bre_new)
  58                         return -ENOMEM;
  59                 append_badrange_entry(badrange, bre_new, addr, length);
  60                 return 0;
  61         }
  62 
  63         /*
  64          * There is a chance this is a duplicate, check for those first.
  65          * This will be the common case as ARS_STATUS returns all known
  66          * errors in the SPA space, and we can't query it per region
  67          */
  68         list_for_each_entry(bre, &badrange->list, list)
  69                 if (bre->start == addr) {
  70                         /* If length has changed, update this list entry */
  71                         if (bre->length != length)
  72                                 bre->length = length;
  73                         kfree(bre_new);
  74                         return 0;
  75                 }
  76 
  77         /*
  78          * If not a duplicate or a simple length update, add the entry as is,
  79          * as any overlapping ranges will get resolved when the list is consumed
  80          * and converted to badblocks
  81          */
  82         if (!bre_new)
  83                 return -ENOMEM;
  84         append_badrange_entry(badrange, bre_new, addr, length);
  85 
  86         return 0;
  87 }
  88 
  89 int badrange_add(struct badrange *badrange, u64 addr, u64 length)
  90 {
  91         int rc;
  92 
  93         spin_lock(&badrange->lock);
  94         rc = add_badrange(badrange, addr, length);
  95         spin_unlock(&badrange->lock);
  96 
  97         return rc;
  98 }
  99 EXPORT_SYMBOL_GPL(badrange_add);
 100 
 101 void badrange_forget(struct badrange *badrange, phys_addr_t start,
 102                 unsigned int len)
 103 {
 104         struct list_head *badrange_list = &badrange->list;
 105         u64 clr_end = start + len - 1;
 106         struct badrange_entry *bre, *next;
 107 
 108         spin_lock(&badrange->lock);
 109 
 110         /*
 111          * [start, clr_end] is the badrange interval being cleared.
 112          * [bre->start, bre_end] is the badrange_list entry we're comparing
 113          * the above interval against. The badrange list entry may need
 114          * to be modified (update either start or length), deleted, or
 115          * split into two based on the overlap characteristics
 116          */
 117 
 118         list_for_each_entry_safe(bre, next, badrange_list, list) {
 119                 u64 bre_end = bre->start + bre->length - 1;
 120 
 121                 /* Skip intervals with no intersection */
 122                 if (bre_end < start)
 123                         continue;
 124                 if (bre->start >  clr_end)
 125                         continue;
 126                 /* Delete completely overlapped badrange entries */
 127                 if ((bre->start >= start) && (bre_end <= clr_end)) {
 128                         list_del(&bre->list);
 129                         kfree(bre);
 130                         continue;
 131                 }
 132                 /* Adjust start point of partially cleared entries */
 133                 if ((start <= bre->start) && (clr_end > bre->start)) {
 134                         bre->length -= clr_end - bre->start + 1;
 135                         bre->start = clr_end + 1;
 136                         continue;
 137                 }
 138                 /* Adjust bre->length for partial clearing at the tail end */
 139                 if ((bre->start < start) && (bre_end <= clr_end)) {
 140                         /* bre->start remains the same */
 141                         bre->length = start - bre->start;
 142                         continue;
 143                 }
 144                 /*
 145                  * If clearing in the middle of an entry, we split it into
 146                  * two by modifying the current entry to represent one half of
 147                  * the split, and adding a new entry for the second half.
 148                  */
 149                 if ((bre->start < start) && (bre_end > clr_end)) {
 150                         u64 new_start = clr_end + 1;
 151                         u64 new_len = bre_end - new_start + 1;
 152 
 153                         /* Add new entry covering the right half */
 154                         alloc_and_append_badrange_entry(badrange, new_start,
 155                                         new_len, GFP_NOWAIT);
 156                         /* Adjust this entry to cover the left half */
 157                         bre->length = start - bre->start;
 158                         continue;
 159                 }
 160         }
 161         spin_unlock(&badrange->lock);
 162 }
 163 EXPORT_SYMBOL_GPL(badrange_forget);
 164 
 165 static void set_badblock(struct badblocks *bb, sector_t s, int num)
 166 {
 167         dev_dbg(bb->dev, "Found a bad range (0x%llx, 0x%llx)\n",
 168                         (u64) s * 512, (u64) num * 512);
 169         /* this isn't an error as the hardware will still throw an exception */
 170         if (badblocks_set(bb, s, num, 1))
 171                 dev_info_once(bb->dev, "%s: failed for sector %llx\n",
 172                                 __func__, (u64) s);
 173 }
 174 
 175 /**
 176  * __add_badblock_range() - Convert a physical address range to bad sectors
 177  * @bb:         badblocks instance to populate
 178  * @ns_offset:  namespace offset where the error range begins (in bytes)
 179  * @len:        number of bytes of badrange to be added
 180  *
 181  * This assumes that the range provided with (ns_offset, len) is within
 182  * the bounds of physical addresses for this namespace, i.e. lies in the
 183  * interval [ns_start, ns_start + ns_size)
 184  */
 185 static void __add_badblock_range(struct badblocks *bb, u64 ns_offset, u64 len)
 186 {
 187         const unsigned int sector_size = 512;
 188         sector_t start_sector, end_sector;
 189         u64 num_sectors;
 190         u32 rem;
 191 
 192         start_sector = div_u64(ns_offset, sector_size);
 193         end_sector = div_u64_rem(ns_offset + len, sector_size, &rem);
 194         if (rem)
 195                 end_sector++;
 196         num_sectors = end_sector - start_sector;
 197 
 198         if (unlikely(num_sectors > (u64)INT_MAX)) {
 199                 u64 remaining = num_sectors;
 200                 sector_t s = start_sector;
 201 
 202                 while (remaining) {
 203                         int done = min_t(u64, remaining, INT_MAX);
 204 
 205                         set_badblock(bb, s, done);
 206                         remaining -= done;
 207                         s += done;
 208                 }
 209         } else
 210                 set_badblock(bb, start_sector, num_sectors);
 211 }
 212 
 213 static void badblocks_populate(struct badrange *badrange,
 214                 struct badblocks *bb, const struct resource *res)
 215 {
 216         struct badrange_entry *bre;
 217 
 218         if (list_empty(&badrange->list))
 219                 return;
 220 
 221         list_for_each_entry(bre, &badrange->list, list) {
 222                 u64 bre_end = bre->start + bre->length - 1;
 223 
 224                 /* Discard intervals with no intersection */
 225                 if (bre_end < res->start)
 226                         continue;
 227                 if (bre->start >  res->end)
 228                         continue;
 229                 /* Deal with any overlap after start of the namespace */
 230                 if (bre->start >= res->start) {
 231                         u64 start = bre->start;
 232                         u64 len;
 233 
 234                         if (bre_end <= res->end)
 235                                 len = bre->length;
 236                         else
 237                                 len = res->start + resource_size(res)
 238                                         - bre->start;
 239                         __add_badblock_range(bb, start - res->start, len);
 240                         continue;
 241                 }
 242                 /*
 243                  * Deal with overlap for badrange starting before
 244                  * the namespace.
 245                  */
 246                 if (bre->start < res->start) {
 247                         u64 len;
 248 
 249                         if (bre_end < res->end)
 250                                 len = bre->start + bre->length - res->start;
 251                         else
 252                                 len = resource_size(res);
 253                         __add_badblock_range(bb, 0, len);
 254                 }
 255         }
 256 }
 257 
 258 /**
 259  * nvdimm_badblocks_populate() - Convert a list of badranges to badblocks
 260  * @region: parent region of the range to interrogate
 261  * @bb: badblocks instance to populate
 262  * @res: resource range to consider
 263  *
 264  * The badrange list generated during bus initialization may contain
 265  * multiple, possibly overlapping physical address ranges.  Compare each
 266  * of these ranges to the resource range currently being initialized,
 267  * and add badblocks entries for all matching sub-ranges
 268  */
 269 void nvdimm_badblocks_populate(struct nd_region *nd_region,
 270                 struct badblocks *bb, const struct resource *res)
 271 {
 272         struct nvdimm_bus *nvdimm_bus;
 273 
 274         if (!is_memory(&nd_region->dev)) {
 275                 dev_WARN_ONCE(&nd_region->dev, 1,
 276                                 "%s only valid for pmem regions\n", __func__);
 277                 return;
 278         }
 279         nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
 280 
 281         nvdimm_bus_lock(&nvdimm_bus->dev);
 282         badblocks_populate(&nvdimm_bus->badrange, bb, res);
 283         nvdimm_bus_unlock(&nvdimm_bus->dev);
 284 }
 285 EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate);