arch/powerpc/mm/drmem.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Dynamic reconfiguration memory support
   4  *
   5  * Copyright 2017 IBM Corporation
   6  */
   7
   8 #define pr_fmt(fmt) "drmem: " fmt
   9
  10 #include <linux/kernel.h>
  11 #include <linux/of.h>
  12 #include <linux/of_fdt.h>
  13 #include <linux/memblock.h>
  14 #include <linux/slab.h>
  15 #include <asm/drmem.h>
  16
  17 static int n_root_addr_cells, n_root_size_cells;
  18
  19 static struct drmem_lmb_info __drmem_info;
  20 struct drmem_lmb_info *drmem_info = &__drmem_info;
  21 static bool in_drmem_update;
  22
  23 u64 drmem_lmb_memory_max(void)
  24 {
  25         struct drmem_lmb *last_lmb;
  26
  27         last_lmb = &drmem_info->lmbs[drmem_info->n_lmbs - 1];
  28         return last_lmb->base_addr + drmem_lmb_size();
  29 }
  30
  31 static u32 drmem_lmb_flags(struct drmem_lmb *lmb)
  32 {
  33         /*
  34          * Return the value of the lmb flags field minus the reserved
  35          * bit used internally for hotplug processing.
  36          */
  37         return lmb->flags & ~DRMEM_LMB_RESERVED;
  38 }
  39
  40 static struct property *clone_property(struct property *prop, u32 prop_sz)
  41 {
  42         struct property *new_prop;
  43
  44         new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
  45         if (!new_prop)
  46                 return NULL;
  47
  48         new_prop->name = kstrdup(prop->name, GFP_KERNEL);
  49         new_prop->value = kzalloc(prop_sz, GFP_KERNEL);
  50         if (!new_prop->name || !new_prop->value) {
  51                 kfree(new_prop->name);
  52                 kfree(new_prop->value);
  53                 kfree(new_prop);
  54                 return NULL;
  55         }
  56
  57         new_prop->length = prop_sz;
  58 #if defined(CONFIG_OF_DYNAMIC)
  59         of_property_set_flag(new_prop, OF_DYNAMIC);
  60 #endif
  61         return new_prop;
  62 }
  63
  64 static int drmem_update_dt_v1(struct device_node *memory,
  65                               struct property *prop)
  66 {
  67         struct property *new_prop;
  68         struct of_drconf_cell_v1 *dr_cell;
  69         struct drmem_lmb *lmb;
  70         __be32 *p;
  71
  72         new_prop = clone_property(prop, prop->length);
  73         if (!new_prop)
  74                 return -1;
  75
  76         p = new_prop->value;
  77         *p++ = cpu_to_be32(drmem_info->n_lmbs);
  78
  79         dr_cell = (struct of_drconf_cell_v1 *)p;
  80
  81         for_each_drmem_lmb(lmb) {
  82                 dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
  83                 dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
  84                 dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
  85                 dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));
  86
  87                 dr_cell++;
  88         }
  89
  90         of_update_property(memory, new_prop);
  91         return 0;
  92 }
  93
  94 static void init_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
  95                                 struct drmem_lmb *lmb)
  96 {
  97         dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
  98         dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
  99         dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
 100         dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));
 101 }
 102
 103 static int drmem_update_dt_v2(struct device_node *memory,
 104                               struct property *prop)
 105 {
 106         struct property *new_prop;
 107         struct of_drconf_cell_v2 *dr_cell;
 108         struct drmem_lmb *lmb, *prev_lmb;
 109         u32 lmb_sets, prop_sz, seq_lmbs;
 110         u32 *p;
 111
 112         /* First pass, determine how many LMB sets are needed. */
 113         lmb_sets = 0;
 114         prev_lmb = NULL;
 115         for_each_drmem_lmb(lmb) {
 116                 if (!prev_lmb) {
 117                         prev_lmb = lmb;
 118                         lmb_sets++;
 119                         continue;
 120                 }
 121
 122                 if (prev_lmb->aa_index != lmb->aa_index ||
 123                     drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb))
 124                         lmb_sets++;
 125
 126                 prev_lmb = lmb;
 127         }
 128
 129         prop_sz = lmb_sets * sizeof(*dr_cell) + sizeof(__be32);
 130         new_prop = clone_property(prop, prop_sz);
 131         if (!new_prop)
 132                 return -1;
 133
 134         p = new_prop->value;
 135         *p++ = cpu_to_be32(lmb_sets);
 136
 137         dr_cell = (struct of_drconf_cell_v2 *)p;
 138
 139         /* Second pass, populate the LMB set data */
 140         prev_lmb = NULL;
 141         seq_lmbs = 0;
 142         for_each_drmem_lmb(lmb) {
 143                 if (prev_lmb == NULL) {
 144                         /* Start of first LMB set */
 145                         prev_lmb = lmb;
 146                         init_drconf_v2_cell(dr_cell, lmb);
 147                         seq_lmbs++;
 148                         continue;
 149                 }
 150
 151                 if (prev_lmb->aa_index != lmb->aa_index ||
 152                     drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb)) {
 153                         /* end of one set, start of another */
 154                         dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
 155                         dr_cell++;
 156
 157                         init_drconf_v2_cell(dr_cell, lmb);
 158                         seq_lmbs = 1;
 159                 } else {
 160                         seq_lmbs++;
 161                 }
 162
 163                 prev_lmb = lmb;
 164         }
 165
 166         /* close out last LMB set */
 167         dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
 168         of_update_property(memory, new_prop);
 169         return 0;
 170 }
 171
 172 int drmem_update_dt(void)
 173 {
 174         struct device_node *memory;
 175         struct property *prop;
 176         int rc = -1;
 177
 178         memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
 179         if (!memory)
 180                 return -1;
 181
 182         /*
 183          * Set in_drmem_update to prevent the notifier callback to process the
 184          * DT property back since the change is coming from the LMB tree.
 185          */
 186         in_drmem_update = true;
 187         prop = of_find_property(memory, "ibm,dynamic-memory", NULL);
 188         if (prop) {
 189                 rc = drmem_update_dt_v1(memory, prop);
 190         } else {
 191                 prop = of_find_property(memory, "ibm,dynamic-memory-v2", NULL);
 192                 if (prop)
 193                         rc = drmem_update_dt_v2(memory, prop);
 194         }
 195         in_drmem_update = false;
 196
 197         of_node_put(memory);
 198         return rc;
 199 }
 200
 201 static void read_drconf_v1_cell(struct drmem_lmb *lmb,
 202                                        const __be32 **prop)
 203 {
 204         const __be32 *p = *prop;
 205
 206         lmb->base_addr = of_read_number(p, n_root_addr_cells);
 207         p += n_root_addr_cells;
 208         lmb->drc_index = of_read_number(p++, 1);
 209
 210         p++; /* skip reserved field */
 211
 212         lmb->aa_index = of_read_number(p++, 1);
 213         lmb->flags = of_read_number(p++, 1);
 214
 215         *prop = p;
 216 }
 217
 218 static int
 219 __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm, void *data,
 220                      int (*func)(struct drmem_lmb *, const __be32 **, void *))
 221 {
 222         struct drmem_lmb lmb;
 223         u32 i, n_lmbs;
 224         int ret = 0;
 225
 226         n_lmbs = of_read_number(prop++, 1);
 227         for (i = 0; i < n_lmbs; i++) {
 228                 read_drconf_v1_cell(&lmb, &prop);
 229                 ret = func(&lmb, &usm, data);
 230                 if (ret)
 231                         break;
 232         }
 233
 234         return ret;
 235 }
 236
 237 static void read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
 238                                        const __be32 **prop)
 239 {
 240         const __be32 *p = *prop;
 241
 242         dr_cell->seq_lmbs = of_read_number(p++, 1);
 243         dr_cell->base_addr = of_read_number(p, n_root_addr_cells);
 244         p += n_root_addr_cells;
 245         dr_cell->drc_index = of_read_number(p++, 1);
 246         dr_cell->aa_index = of_read_number(p++, 1);
 247         dr_cell->flags = of_read_number(p++, 1);
 248
 249         *prop = p;
 250 }
 251
 252 static int
 253 __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm, void *data,
 254                      int (*func)(struct drmem_lmb *, const __be32 **, void *))
 255 {
 256         struct of_drconf_cell_v2 dr_cell;
 257         struct drmem_lmb lmb;
 258         u32 i, j, lmb_sets;
 259         int ret = 0;
 260
 261         lmb_sets = of_read_number(prop++, 1);
 262         for (i = 0; i < lmb_sets; i++) {
 263                 read_drconf_v2_cell(&dr_cell, &prop);
 264
 265                 for (j = 0; j < dr_cell.seq_lmbs; j++) {
 266                         lmb.base_addr = dr_cell.base_addr;
 267                         dr_cell.base_addr += drmem_lmb_size();
 268
 269                         lmb.drc_index = dr_cell.drc_index;
 270                         dr_cell.drc_index++;
 271
 272                         lmb.aa_index = dr_cell.aa_index;
 273                         lmb.flags = dr_cell.flags;
 274
 275                         ret = func(&lmb, &usm, data);
 276                         if (ret)
 277                                 break;
 278                 }
 279         }
 280
 281         return ret;
 282 }
 283
 284 #ifdef CONFIG_PPC_PSERIES
 285 int __init walk_drmem_lmbs_early(unsigned long node, void *data,
 286                 int (*func)(struct drmem_lmb *, const __be32 **, void *))
 287 {
 288         const __be32 *prop, *usm;
 289         int len, ret = -ENODEV;
 290
 291         prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
 292         if (!prop || len < dt_root_size_cells * sizeof(__be32))
 293                 return ret;
 294
 295         /* Get the address & size cells */
 296         n_root_addr_cells = dt_root_addr_cells;
 297         n_root_size_cells = dt_root_size_cells;
 298
 299         drmem_info->lmb_size = dt_mem_next_cell(dt_root_size_cells, &prop);
 300
 301         usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory", &len);
 302
 303         prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &len);
 304         if (prop) {
 305                 ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
 306         } else {
 307                 prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory-v2",
 308                                            &len);
 309                 if (prop)
 310                         ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
 311         }
 312
 313         memblock_dump_all();
 314         return ret;
 315 }
 316
 317 /*
 318  * Update the LMB associativity index.
 319  */
 320 static int update_lmb(struct drmem_lmb *updated_lmb,
 321                       __maybe_unused const __be32 **usm,
 322                       __maybe_unused void *data)
 323 {
 324         struct drmem_lmb *lmb;
 325
 326         for_each_drmem_lmb(lmb) {
 327                 if (lmb->drc_index != updated_lmb->drc_index)
 328                         continue;
 329
 330                 lmb->aa_index = updated_lmb->aa_index;
 331                 break;
 332         }
 333         return 0;
 334 }
 335
 336 /*
 337  * Update the LMB associativity index.
 338  *
 339  * This needs to be called when the hypervisor is updating the
 340  * dynamic-reconfiguration-memory node property.
 341  */
 342 void drmem_update_lmbs(struct property *prop)
 343 {
 344         /*
 345          * Don't update the LMBs if triggered by the update done in
 346          * drmem_update_dt(), the LMB values have been used to the update the DT
 347          * property in that case.
 348          */
 349         if (in_drmem_update)
 350                 return;
 351         if (!strcmp(prop->name, "ibm,dynamic-memory"))
 352                 __walk_drmem_v1_lmbs(prop->value, NULL, NULL, update_lmb);
 353         else if (!strcmp(prop->name, "ibm,dynamic-memory-v2"))
 354                 __walk_drmem_v2_lmbs(prop->value, NULL, NULL, update_lmb);
 355 }
 356 #endif
 357
 358 static int init_drmem_lmb_size(struct device_node *dn)
 359 {
 360         const __be32 *prop;
 361         int len;
 362
 363         if (drmem_info->lmb_size)
 364                 return 0;
 365
 366         prop = of_get_property(dn, "ibm,lmb-size", &len);
 367         if (!prop || len < n_root_size_cells * sizeof(__be32)) {
 368                 pr_info("Could not determine LMB size\n");
 369                 return -1;
 370         }
 371
 372         drmem_info->lmb_size = of_read_number(prop, n_root_size_cells);
 373         return 0;
 374 }
 375
 376 /*
 377  * Returns the property linux,drconf-usable-memory if
 378  * it exists (the property exists only in kexec/kdump kernels,
 379  * added by kexec-tools)
 380  */
 381 static const __be32 *of_get_usable_memory(struct device_node *dn)
 382 {
 383         const __be32 *prop;
 384         u32 len;
 385
 386         prop = of_get_property(dn, "linux,drconf-usable-memory", &len);
 387         if (!prop || len < sizeof(unsigned int))
 388                 return NULL;
 389
 390         return prop;
 391 }
 392
 393 int walk_drmem_lmbs(struct device_node *dn, void *data,
 394                     int (*func)(struct drmem_lmb *, const __be32 **, void *))
 395 {
 396         struct device_node *root = of_find_node_by_path("/");
 397         const __be32 *prop, *usm;
 398         int ret = -ENODEV;
 399
 400         if (!root)
 401                 return ret;
 402
 403         /* Get the address & size cells */
 404         n_root_addr_cells = of_n_addr_cells(root);
 405         n_root_size_cells = of_n_size_cells(root);
 406         of_node_put(root);
 407
 408         if (init_drmem_lmb_size(dn))
 409                 return ret;
 410
 411         usm = of_get_usable_memory(dn);
 412
 413         prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
 414         if (prop) {
 415                 ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
 416         } else {
 417                 prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
 418                 if (prop)
 419                         ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
 420         }
 421
 422         return ret;
 423 }
 424
 425 static void __init init_drmem_v1_lmbs(const __be32 *prop)
 426 {
 427         struct drmem_lmb *lmb;
 428
 429         drmem_info->n_lmbs = of_read_number(prop++, 1);
 430         if (drmem_info->n_lmbs == 0)
 431                 return;
 432
 433         drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
 434                                    GFP_KERNEL);
 435         if (!drmem_info->lmbs)
 436                 return;
 437
 438         for_each_drmem_lmb(lmb)
 439                 read_drconf_v1_cell(lmb, &prop);
 440 }
 441
 442 static void __init init_drmem_v2_lmbs(const __be32 *prop)
 443 {
 444         struct drmem_lmb *lmb;
 445         struct of_drconf_cell_v2 dr_cell;
 446         const __be32 *p;
 447         u32 i, j, lmb_sets;
 448         int lmb_index;
 449
 450         lmb_sets = of_read_number(prop++, 1);
 451         if (lmb_sets == 0)
 452                 return;
 453
 454         /* first pass, calculate the number of LMBs */
 455         p = prop;
 456         for (i = 0; i < lmb_sets; i++) {
 457                 read_drconf_v2_cell(&dr_cell, &p);
 458                 drmem_info->n_lmbs += dr_cell.seq_lmbs;
 459         }
 460
 461         drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
 462                                    GFP_KERNEL);
 463         if (!drmem_info->lmbs)
 464                 return;
 465
 466         /* second pass, read in the LMB information */
 467         lmb_index = 0;
 468         p = prop;
 469
 470         for (i = 0; i < lmb_sets; i++) {
 471                 read_drconf_v2_cell(&dr_cell, &p);
 472
 473                 for (j = 0; j < dr_cell.seq_lmbs; j++) {
 474                         lmb = &drmem_info->lmbs[lmb_index++];
 475
 476                         lmb->base_addr = dr_cell.base_addr;
 477                         dr_cell.base_addr += drmem_info->lmb_size;
 478
 479                         lmb->drc_index = dr_cell.drc_index;
 480                         dr_cell.drc_index++;
 481
 482                         lmb->aa_index = dr_cell.aa_index;
 483                         lmb->flags = dr_cell.flags;
 484                 }
 485         }
 486 }
 487
 488 static int __init drmem_init(void)
 489 {
 490         struct device_node *dn;
 491         const __be32 *prop;
 492
 493         dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
 494         if (!dn) {
 495                 pr_info("No dynamic reconfiguration memory found\n");
 496                 return 0;
 497         }
 498
 499         if (init_drmem_lmb_size(dn)) {
 500                 of_node_put(dn);
 501                 return 0;
 502         }
 503
 504         prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
 505         if (prop) {
 506                 init_drmem_v1_lmbs(prop);
 507         } else {
 508                 prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
 509                 if (prop)
 510                         init_drmem_v2_lmbs(prop);
 511         }
 512
 513         of_node_put(dn);
 514         return 0;
 515 }
 516 late_initcall(drmem_init);