Dan Williams | 4a826c8 | 2015-06-09 16:09:36 -0400 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright(c) 2013-2015 Intel Corporation. All rights reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of version 2 of the GNU General Public License as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but |
| 9 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 11 | * General Public License for more details. |
| 12 | */ |
| 13 | #include <linux/device.h> |
| 14 | #include <linux/ndctl.h> |
| 15 | #include <linux/io.h> |
| 16 | #include <linux/nd.h> |
| 17 | #include "nd-core.h" |
| 18 | #include "label.h" |
| 19 | #include "nd.h" |
| 20 | |
| 21 | static u32 best_seq(u32 a, u32 b) |
| 22 | { |
| 23 | a &= NSINDEX_SEQ_MASK; |
| 24 | b &= NSINDEX_SEQ_MASK; |
| 25 | |
| 26 | if (a == 0 || a == b) |
| 27 | return b; |
| 28 | else if (b == 0) |
| 29 | return a; |
| 30 | else if (nd_inc_seq(a) == b) |
| 31 | return b; |
| 32 | else |
| 33 | return a; |
| 34 | } |
| 35 | |
| 36 | size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd) |
| 37 | { |
| 38 | u32 index_span; |
| 39 | |
| 40 | if (ndd->nsindex_size) |
| 41 | return ndd->nsindex_size; |
| 42 | |
| 43 | /* |
| 44 | * The minimum index space is 512 bytes, with that amount of |
| 45 | * index we can describe ~1400 labels which is less than a byte |
| 46 | * of overhead per label. Round up to a byte of overhead per |
| 47 | * label and determine the size of the index region. Yes, this |
| 48 | * starts to waste space at larger config_sizes, but it's |
| 49 | * unlikely we'll ever see anything but 128K. |
| 50 | */ |
| 51 | index_span = ndd->nsarea.config_size / 129; |
| 52 | index_span /= NSINDEX_ALIGN * 2; |
| 53 | ndd->nsindex_size = index_span * NSINDEX_ALIGN; |
| 54 | |
| 55 | return ndd->nsindex_size; |
| 56 | } |
| 57 | |
| 58 | int nd_label_validate(struct nvdimm_drvdata *ndd) |
| 59 | { |
| 60 | /* |
| 61 | * On media label format consists of two index blocks followed |
| 62 | * by an array of labels. None of these structures are ever |
| 63 | * updated in place. A sequence number tracks the current |
| 64 | * active index and the next one to write, while labels are |
| 65 | * written to free slots. |
| 66 | * |
| 67 | * +------------+ |
| 68 | * | | |
| 69 | * | nsindex0 | |
| 70 | * | | |
| 71 | * +------------+ |
| 72 | * | | |
| 73 | * | nsindex1 | |
| 74 | * | | |
| 75 | * +------------+ |
| 76 | * | label0 | |
| 77 | * +------------+ |
| 78 | * | label1 | |
| 79 | * +------------+ |
| 80 | * | | |
| 81 | * ....nslot... |
| 82 | * | | |
| 83 | * +------------+ |
| 84 | * | labelN | |
| 85 | * +------------+ |
| 86 | */ |
| 87 | struct nd_namespace_index *nsindex[] = { |
| 88 | to_namespace_index(ndd, 0), |
| 89 | to_namespace_index(ndd, 1), |
| 90 | }; |
| 91 | const int num_index = ARRAY_SIZE(nsindex); |
| 92 | struct device *dev = ndd->dev; |
| 93 | bool valid[2] = { 0 }; |
| 94 | int i, num_valid = 0; |
| 95 | u32 seq; |
| 96 | |
| 97 | for (i = 0; i < num_index; i++) { |
| 98 | u32 nslot; |
| 99 | u8 sig[NSINDEX_SIG_LEN]; |
| 100 | u64 sum_save, sum, size; |
| 101 | |
| 102 | memcpy(sig, nsindex[i]->sig, NSINDEX_SIG_LEN); |
| 103 | if (memcmp(sig, NSINDEX_SIGNATURE, NSINDEX_SIG_LEN) != 0) { |
| 104 | dev_dbg(dev, "%s: nsindex%d signature invalid\n", |
| 105 | __func__, i); |
| 106 | continue; |
| 107 | } |
| 108 | sum_save = __le64_to_cpu(nsindex[i]->checksum); |
| 109 | nsindex[i]->checksum = __cpu_to_le64(0); |
| 110 | sum = nd_fletcher64(nsindex[i], sizeof_namespace_index(ndd), 1); |
| 111 | nsindex[i]->checksum = __cpu_to_le64(sum_save); |
| 112 | if (sum != sum_save) { |
| 113 | dev_dbg(dev, "%s: nsindex%d checksum invalid\n", |
| 114 | __func__, i); |
| 115 | continue; |
| 116 | } |
| 117 | |
| 118 | seq = __le32_to_cpu(nsindex[i]->seq); |
| 119 | if ((seq & NSINDEX_SEQ_MASK) == 0) { |
| 120 | dev_dbg(dev, "%s: nsindex%d sequence: %#x invalid\n", |
| 121 | __func__, i, seq); |
| 122 | continue; |
| 123 | } |
| 124 | |
| 125 | /* sanity check the index against expected values */ |
| 126 | if (__le64_to_cpu(nsindex[i]->myoff) |
| 127 | != i * sizeof_namespace_index(ndd)) { |
| 128 | dev_dbg(dev, "%s: nsindex%d myoff: %#llx invalid\n", |
| 129 | __func__, i, (unsigned long long) |
| 130 | __le64_to_cpu(nsindex[i]->myoff)); |
| 131 | continue; |
| 132 | } |
| 133 | if (__le64_to_cpu(nsindex[i]->otheroff) |
| 134 | != (!i) * sizeof_namespace_index(ndd)) { |
| 135 | dev_dbg(dev, "%s: nsindex%d otheroff: %#llx invalid\n", |
| 136 | __func__, i, (unsigned long long) |
| 137 | __le64_to_cpu(nsindex[i]->otheroff)); |
| 138 | continue; |
| 139 | } |
| 140 | |
| 141 | size = __le64_to_cpu(nsindex[i]->mysize); |
| 142 | if (size > sizeof_namespace_index(ndd) |
| 143 | || size < sizeof(struct nd_namespace_index)) { |
| 144 | dev_dbg(dev, "%s: nsindex%d mysize: %#llx invalid\n", |
| 145 | __func__, i, size); |
| 146 | continue; |
| 147 | } |
| 148 | |
| 149 | nslot = __le32_to_cpu(nsindex[i]->nslot); |
| 150 | if (nslot * sizeof(struct nd_namespace_label) |
| 151 | + 2 * sizeof_namespace_index(ndd) |
| 152 | > ndd->nsarea.config_size) { |
| 153 | dev_dbg(dev, "%s: nsindex%d nslot: %u invalid, config_size: %#x\n", |
| 154 | __func__, i, nslot, |
| 155 | ndd->nsarea.config_size); |
| 156 | continue; |
| 157 | } |
| 158 | valid[i] = true; |
| 159 | num_valid++; |
| 160 | } |
| 161 | |
| 162 | switch (num_valid) { |
| 163 | case 0: |
| 164 | break; |
| 165 | case 1: |
| 166 | for (i = 0; i < num_index; i++) |
| 167 | if (valid[i]) |
| 168 | return i; |
| 169 | /* can't have num_valid > 0 but valid[] = { false, false } */ |
| 170 | WARN_ON(1); |
| 171 | break; |
| 172 | default: |
| 173 | /* pick the best index... */ |
| 174 | seq = best_seq(__le32_to_cpu(nsindex[0]->seq), |
| 175 | __le32_to_cpu(nsindex[1]->seq)); |
| 176 | if (seq == (__le32_to_cpu(nsindex[1]->seq) & NSINDEX_SEQ_MASK)) |
| 177 | return 1; |
| 178 | else |
| 179 | return 0; |
| 180 | break; |
| 181 | } |
| 182 | |
| 183 | return -1; |
| 184 | } |
| 185 | |
| 186 | void nd_label_copy(struct nvdimm_drvdata *ndd, struct nd_namespace_index *dst, |
| 187 | struct nd_namespace_index *src) |
| 188 | { |
| 189 | if (dst && src) |
| 190 | /* pass */; |
| 191 | else |
| 192 | return; |
| 193 | |
| 194 | memcpy(dst, src, sizeof_namespace_index(ndd)); |
| 195 | } |
| 196 | |
| 197 | static struct nd_namespace_label *nd_label_base(struct nvdimm_drvdata *ndd) |
| 198 | { |
| 199 | void *base = to_namespace_index(ndd, 0); |
| 200 | |
| 201 | return base + 2 * sizeof_namespace_index(ndd); |
| 202 | } |
| 203 | |
| 204 | #define for_each_clear_bit_le(bit, addr, size) \ |
| 205 | for ((bit) = find_next_zero_bit_le((addr), (size), 0); \ |
| 206 | (bit) < (size); \ |
| 207 | (bit) = find_next_zero_bit_le((addr), (size), (bit) + 1)) |
| 208 | |
| 209 | /** |
| 210 | * preamble_current - common variable initialization for nd_label_* routines |
| 211 | * @ndd: dimm container for the relevant label set |
| 212 | * @nsindex_out: on return set to the currently active namespace index |
| 213 | * @free: on return set to the free label bitmap in the index |
| 214 | * @nslot: on return set to the number of slots in the label space |
| 215 | */ |
| 216 | static bool preamble_current(struct nvdimm_drvdata *ndd, |
| 217 | struct nd_namespace_index **nsindex_out, |
| 218 | unsigned long **free, u32 *nslot) |
| 219 | { |
| 220 | struct nd_namespace_index *nsindex; |
| 221 | |
| 222 | nsindex = to_current_namespace_index(ndd); |
| 223 | if (nsindex == NULL) |
| 224 | return false; |
| 225 | |
| 226 | *free = (unsigned long *) nsindex->free; |
| 227 | *nslot = __le32_to_cpu(nsindex->nslot); |
| 228 | *nsindex_out = nsindex; |
| 229 | |
| 230 | return true; |
| 231 | } |
| 232 | |
| 233 | static char *nd_label_gen_id(struct nd_label_id *label_id, u8 *uuid, u32 flags) |
| 234 | { |
| 235 | if (!label_id || !uuid) |
| 236 | return NULL; |
| 237 | snprintf(label_id->id, ND_LABEL_ID_SIZE, "%s-%pUb", |
| 238 | flags & NSLABEL_FLAG_LOCAL ? "blk" : "pmem", uuid); |
| 239 | return label_id->id; |
| 240 | } |
| 241 | |
| 242 | static bool slot_valid(struct nd_namespace_label *nd_label, u32 slot) |
| 243 | { |
| 244 | /* check that we are written where we expect to be written */ |
| 245 | if (slot != __le32_to_cpu(nd_label->slot)) |
| 246 | return false; |
| 247 | |
| 248 | /* check that DPA allocations are page aligned */ |
| 249 | if ((__le64_to_cpu(nd_label->dpa) |
| 250 | | __le64_to_cpu(nd_label->rawsize)) % SZ_4K) |
| 251 | return false; |
| 252 | |
| 253 | return true; |
| 254 | } |
| 255 | |
| 256 | int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd) |
| 257 | { |
| 258 | struct nd_namespace_index *nsindex; |
| 259 | unsigned long *free; |
| 260 | u32 nslot, slot; |
| 261 | |
| 262 | if (!preamble_current(ndd, &nsindex, &free, &nslot)) |
| 263 | return 0; /* no label, nothing to reserve */ |
| 264 | |
| 265 | for_each_clear_bit_le(slot, free, nslot) { |
| 266 | struct nd_namespace_label *nd_label; |
| 267 | struct nd_region *nd_region = NULL; |
| 268 | u8 label_uuid[NSLABEL_UUID_LEN]; |
| 269 | struct nd_label_id label_id; |
| 270 | struct resource *res; |
| 271 | u32 flags; |
| 272 | |
| 273 | nd_label = nd_label_base(ndd) + slot; |
| 274 | |
| 275 | if (!slot_valid(nd_label, slot)) |
| 276 | continue; |
| 277 | |
| 278 | memcpy(label_uuid, nd_label->uuid, NSLABEL_UUID_LEN); |
| 279 | flags = __le32_to_cpu(nd_label->flags); |
| 280 | nd_label_gen_id(&label_id, label_uuid, flags); |
| 281 | res = nvdimm_allocate_dpa(ndd, &label_id, |
| 282 | __le64_to_cpu(nd_label->dpa), |
| 283 | __le64_to_cpu(nd_label->rawsize)); |
| 284 | nd_dbg_dpa(nd_region, ndd, res, "reserve\n"); |
| 285 | if (!res) |
| 286 | return -EBUSY; |
| 287 | } |
| 288 | |
| 289 | return 0; |
| 290 | } |