1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Dynamic reconfiguration memory support
5 * Copyright 2017 IBM Corporation
8 #define pr_fmt(fmt) "drmem: " fmt
10 #include <linux/kernel.h>
12 #include <linux/of_fdt.h>
13 #include <linux/memblock.h>
14 #include <linux/slab.h>
15 #include <asm/drmem.h>
17 static int n_root_addr_cells, n_root_size_cells;
19 static struct drmem_lmb_info __drmem_info;
20 struct drmem_lmb_info *drmem_info = &__drmem_info;
21 static bool in_drmem_update;
23 u64 drmem_lmb_memory_max(void)
25 struct drmem_lmb *last_lmb;
27 last_lmb = &drmem_info->lmbs[drmem_info->n_lmbs - 1];
28 return last_lmb->base_addr + drmem_lmb_size();
31 static u32 drmem_lmb_flags(struct drmem_lmb *lmb)
34 * Return the value of the lmb flags field minus the reserved
35 * bit used internally for hotplug processing.
37 return lmb->flags & ~DRMEM_LMB_RESERVED;
40 static struct property *clone_property(struct property *prop, u32 prop_sz)
42 struct property *new_prop;
44 new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
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);
57 new_prop->length = prop_sz;
58 #if defined(CONFIG_OF_DYNAMIC)
59 of_property_set_flag(new_prop, OF_DYNAMIC);
64 static int drmem_update_dt_v1(struct device_node *memory,
65 struct property *prop)
67 struct property *new_prop;
68 struct of_drconf_cell_v1 *dr_cell;
69 struct drmem_lmb *lmb;
72 new_prop = clone_property(prop, prop->length);
77 *p++ = cpu_to_be32(drmem_info->n_lmbs);
79 dr_cell = (struct of_drconf_cell_v1 *)p;
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));
90 of_update_property(memory, new_prop);
94 static void init_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
95 struct drmem_lmb *lmb)
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));
103 static int drmem_update_dt_v2(struct device_node *memory,
104 struct property *prop)
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;
112 /* First pass, determine how many LMB sets are needed. */
115 for_each_drmem_lmb(lmb) {
122 if (prev_lmb->aa_index != lmb->aa_index ||
123 drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb))
129 prop_sz = lmb_sets * sizeof(*dr_cell) + sizeof(__be32);
130 new_prop = clone_property(prop, prop_sz);
135 *p++ = cpu_to_be32(lmb_sets);
137 dr_cell = (struct of_drconf_cell_v2 *)p;
139 /* Second pass, populate the LMB set data */
142 for_each_drmem_lmb(lmb) {
143 if (prev_lmb == NULL) {
144 /* Start of first LMB set */
146 init_drconf_v2_cell(dr_cell, lmb);
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);
157 init_drconf_v2_cell(dr_cell, lmb);
166 /* close out last LMB set */
167 dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
168 of_update_property(memory, new_prop);
172 int drmem_update_dt(void)
174 struct device_node *memory;
175 struct property *prop;
178 memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
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.
186 in_drmem_update = true;
187 prop = of_find_property(memory, "ibm,dynamic-memory", NULL);
189 rc = drmem_update_dt_v1(memory, prop);
191 prop = of_find_property(memory, "ibm,dynamic-memory-v2", NULL);
193 rc = drmem_update_dt_v2(memory, prop);
195 in_drmem_update = false;
201 static void read_drconf_v1_cell(struct drmem_lmb *lmb,
204 const __be32 *p = *prop;
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);
210 p++; /* skip reserved field */
212 lmb->aa_index = of_read_number(p++, 1);
213 lmb->flags = of_read_number(p++, 1);
219 __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm, void *data,
220 int (*func)(struct drmem_lmb *, const __be32 **, void *))
222 struct drmem_lmb lmb;
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);
237 static void read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
240 const __be32 *p = *prop;
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);
253 __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm, void *data,
254 int (*func)(struct drmem_lmb *, const __be32 **, void *))
256 struct of_drconf_cell_v2 dr_cell;
257 struct drmem_lmb lmb;
261 lmb_sets = of_read_number(prop++, 1);
262 for (i = 0; i < lmb_sets; i++) {
263 read_drconf_v2_cell(&dr_cell, &prop);
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();
269 lmb.drc_index = dr_cell.drc_index;
272 lmb.aa_index = dr_cell.aa_index;
273 lmb.flags = dr_cell.flags;
275 ret = func(&lmb, &usm, data);
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 *))
288 const __be32 *prop, *usm;
289 int len, ret = -ENODEV;
291 prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
292 if (!prop || len < dt_root_size_cells * sizeof(__be32))
295 /* Get the address & size cells */
296 n_root_addr_cells = dt_root_addr_cells;
297 n_root_size_cells = dt_root_size_cells;
299 drmem_info->lmb_size = dt_mem_next_cell(dt_root_size_cells, &prop);
301 usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory", &len);
303 prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &len);
305 ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
307 prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory-v2",
310 ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
318 * Update the LMB associativity index.
320 static int update_lmb(struct drmem_lmb *updated_lmb,
321 __maybe_unused const __be32 **usm,
322 __maybe_unused void *data)
324 struct drmem_lmb *lmb;
326 for_each_drmem_lmb(lmb) {
327 if (lmb->drc_index != updated_lmb->drc_index)
330 lmb->aa_index = updated_lmb->aa_index;
337 * Update the LMB associativity index.
339 * This needs to be called when the hypervisor is updating the
340 * dynamic-reconfiguration-memory node property.
342 void drmem_update_lmbs(struct property *prop)
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.
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);
358 static int init_drmem_lmb_size(struct device_node *dn)
363 if (drmem_info->lmb_size)
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");
372 drmem_info->lmb_size = of_read_number(prop, n_root_size_cells);
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)
381 static const __be32 *of_get_usable_memory(struct device_node *dn)
386 prop = of_get_property(dn, "linux,drconf-usable-memory", &len);
387 if (!prop || len < sizeof(unsigned int))
393 int walk_drmem_lmbs(struct device_node *dn, void *data,
394 int (*func)(struct drmem_lmb *, const __be32 **, void *))
396 const __be32 *prop, *usm;
402 /* Get the address & size cells */
403 of_node_get(of_root);
404 n_root_addr_cells = of_n_addr_cells(of_root);
405 n_root_size_cells = of_n_size_cells(of_root);
406 of_node_put(of_root);
408 if (init_drmem_lmb_size(dn))
411 usm = of_get_usable_memory(dn);
413 prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
415 ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
417 prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
419 ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
425 static void __init init_drmem_v1_lmbs(const __be32 *prop)
427 struct drmem_lmb *lmb;
429 drmem_info->n_lmbs = of_read_number(prop++, 1);
430 if (drmem_info->n_lmbs == 0)
433 drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
435 if (!drmem_info->lmbs)
438 for_each_drmem_lmb(lmb)
439 read_drconf_v1_cell(lmb, &prop);
442 static void __init init_drmem_v2_lmbs(const __be32 *prop)
444 struct drmem_lmb *lmb;
445 struct of_drconf_cell_v2 dr_cell;
450 lmb_sets = of_read_number(prop++, 1);
454 /* first pass, calculate the number of LMBs */
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;
461 drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
463 if (!drmem_info->lmbs)
466 /* second pass, read in the LMB information */
470 for (i = 0; i < lmb_sets; i++) {
471 read_drconf_v2_cell(&dr_cell, &p);
473 for (j = 0; j < dr_cell.seq_lmbs; j++) {
474 lmb = &drmem_info->lmbs[lmb_index++];
476 lmb->base_addr = dr_cell.base_addr;
477 dr_cell.base_addr += drmem_info->lmb_size;
479 lmb->drc_index = dr_cell.drc_index;
482 lmb->aa_index = dr_cell.aa_index;
483 lmb->flags = dr_cell.flags;
488 static int __init drmem_init(void)
490 struct device_node *dn;
493 dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
495 pr_info("No dynamic reconfiguration memory found\n");
499 if (init_drmem_lmb_size(dn)) {
504 prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
506 init_drmem_v1_lmbs(prop);
508 prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
510 init_drmem_v2_lmbs(prop);
516 late_initcall(drmem_init);