arch/powerpc/mm/drmem.c

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