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