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>
15 #include <asm/drmem.h>
17 static struct drmem_lmb_info __drmem_info;
18 struct drmem_lmb_info *drmem_info = &__drmem_info;
20 u64 drmem_lmb_memory_max(void)
22 struct drmem_lmb *last_lmb;
24 last_lmb = &drmem_info->lmbs[drmem_info->n_lmbs - 1];
25 return last_lmb->base_addr + drmem_lmb_size();
28 static u32 drmem_lmb_flags(struct drmem_lmb *lmb)
31 * Return the value of the lmb flags field minus the reserved
32 * bit used internally for hotplug processing.
34 return lmb->flags & ~DRMEM_LMB_RESERVED;
37 static struct property *clone_property(struct property *prop, u32 prop_sz)
39 struct property *new_prop;
41 new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
45 new_prop->name = kstrdup(prop->name, GFP_KERNEL);
46 new_prop->value = kzalloc(prop_sz, GFP_KERNEL);
47 if (!new_prop->name || !new_prop->value) {
48 kfree(new_prop->name);
49 kfree(new_prop->value);
54 new_prop->length = prop_sz;
55 #if defined(CONFIG_OF_DYNAMIC)
56 of_property_set_flag(new_prop, OF_DYNAMIC);
61 static int drmem_update_dt_v1(struct device_node *memory,
62 struct property *prop)
64 struct property *new_prop;
65 struct of_drconf_cell_v1 *dr_cell;
66 struct drmem_lmb *lmb;
69 new_prop = clone_property(prop, prop->length);
74 *p++ = cpu_to_be32(drmem_info->n_lmbs);
76 dr_cell = (struct of_drconf_cell_v1 *)p;
78 for_each_drmem_lmb(lmb) {
79 dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
80 dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
81 dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
82 dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));
87 of_update_property(memory, new_prop);
91 static void init_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
92 struct drmem_lmb *lmb)
94 dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
95 dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
96 dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
97 dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));
100 static int drmem_update_dt_v2(struct device_node *memory,
101 struct property *prop)
103 struct property *new_prop;
104 struct of_drconf_cell_v2 *dr_cell;
105 struct drmem_lmb *lmb, *prev_lmb;
106 u32 lmb_sets, prop_sz, seq_lmbs;
109 /* First pass, determine how many LMB sets are needed. */
112 for_each_drmem_lmb(lmb) {
119 if (prev_lmb->aa_index != lmb->aa_index ||
120 drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb))
126 prop_sz = lmb_sets * sizeof(*dr_cell) + sizeof(__be32);
127 new_prop = clone_property(prop, prop_sz);
132 *p++ = cpu_to_be32(lmb_sets);
134 dr_cell = (struct of_drconf_cell_v2 *)p;
136 /* Second pass, populate the LMB set data */
139 for_each_drmem_lmb(lmb) {
140 if (prev_lmb == NULL) {
141 /* Start of first LMB set */
143 init_drconf_v2_cell(dr_cell, lmb);
148 if (prev_lmb->aa_index != lmb->aa_index ||
149 drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb)) {
150 /* end of one set, start of another */
151 dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
154 init_drconf_v2_cell(dr_cell, lmb);
163 /* close out last LMB set */
164 dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
165 of_update_property(memory, new_prop);
169 int drmem_update_dt(void)
171 struct device_node *memory;
172 struct property *prop;
175 memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
179 prop = of_find_property(memory, "ibm,dynamic-memory", NULL);
181 rc = drmem_update_dt_v1(memory, prop);
183 prop = of_find_property(memory, "ibm,dynamic-memory-v2", NULL);
185 rc = drmem_update_dt_v2(memory, prop);
192 static void __init read_drconf_v1_cell(struct drmem_lmb *lmb,
195 const __be32 *p = *prop;
197 lmb->base_addr = dt_mem_next_cell(dt_root_addr_cells, &p);
198 lmb->drc_index = of_read_number(p++, 1);
200 p++; /* skip reserved field */
202 lmb->aa_index = of_read_number(p++, 1);
203 lmb->flags = of_read_number(p++, 1);
208 static void __init __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm,
209 void (*func)(struct drmem_lmb *, const __be32 **))
211 struct drmem_lmb lmb;
214 n_lmbs = of_read_number(prop++, 1);
218 for (i = 0; i < n_lmbs; i++) {
219 read_drconf_v1_cell(&lmb, &prop);
224 static void __init read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
227 const __be32 *p = *prop;
229 dr_cell->seq_lmbs = of_read_number(p++, 1);
230 dr_cell->base_addr = dt_mem_next_cell(dt_root_addr_cells, &p);
231 dr_cell->drc_index = of_read_number(p++, 1);
232 dr_cell->aa_index = of_read_number(p++, 1);
233 dr_cell->flags = of_read_number(p++, 1);
238 static void __init __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm,
239 void (*func)(struct drmem_lmb *, const __be32 **))
241 struct of_drconf_cell_v2 dr_cell;
242 struct drmem_lmb lmb;
245 lmb_sets = of_read_number(prop++, 1);
249 for (i = 0; i < lmb_sets; i++) {
250 read_drconf_v2_cell(&dr_cell, &prop);
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();
256 lmb.drc_index = dr_cell.drc_index;
259 lmb.aa_index = dr_cell.aa_index;
260 lmb.flags = dr_cell.flags;
267 #ifdef CONFIG_PPC_PSERIES
268 void __init walk_drmem_lmbs_early(unsigned long node,
269 void (*func)(struct drmem_lmb *, const __be32 **))
271 const __be32 *prop, *usm;
274 prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
275 if (!prop || len < dt_root_size_cells * sizeof(__be32))
278 drmem_info->lmb_size = dt_mem_next_cell(dt_root_size_cells, &prop);
280 usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory", &len);
282 prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &len);
284 __walk_drmem_v1_lmbs(prop, usm, func);
286 prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory-v2",
289 __walk_drmem_v2_lmbs(prop, usm, func);
297 static int __init init_drmem_lmb_size(struct device_node *dn)
302 if (drmem_info->lmb_size)
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");
311 drmem_info->lmb_size = dt_mem_next_cell(dt_root_size_cells, &prop);
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)
320 static const __be32 *of_get_usable_memory(struct device_node *dn)
325 prop = of_get_property(dn, "linux,drconf-usable-memory", &len);
326 if (!prop || len < sizeof(unsigned int))
332 void __init walk_drmem_lmbs(struct device_node *dn,
333 void (*func)(struct drmem_lmb *, const __be32 **))
335 const __be32 *prop, *usm;
337 if (init_drmem_lmb_size(dn))
340 usm = of_get_usable_memory(dn);
342 prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
344 __walk_drmem_v1_lmbs(prop, usm, func);
346 prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
348 __walk_drmem_v2_lmbs(prop, usm, func);
352 static void __init init_drmem_v1_lmbs(const __be32 *prop)
354 struct drmem_lmb *lmb;
356 drmem_info->n_lmbs = of_read_number(prop++, 1);
357 if (drmem_info->n_lmbs == 0)
360 drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
362 if (!drmem_info->lmbs)
365 for_each_drmem_lmb(lmb) {
366 read_drconf_v1_cell(lmb, &prop);
371 static void __init init_drmem_v2_lmbs(const __be32 *prop)
373 struct drmem_lmb *lmb;
374 struct of_drconf_cell_v2 dr_cell;
379 lmb_sets = of_read_number(prop++, 1);
383 /* first pass, calculate the number of LMBs */
385 for (i = 0; i < lmb_sets; i++) {
386 read_drconf_v2_cell(&dr_cell, &p);
387 drmem_info->n_lmbs += dr_cell.seq_lmbs;
390 drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
392 if (!drmem_info->lmbs)
395 /* second pass, read in the LMB information */
399 for (i = 0; i < lmb_sets; i++) {
400 read_drconf_v2_cell(&dr_cell, &p);
402 for (j = 0; j < dr_cell.seq_lmbs; j++) {
403 lmb = &drmem_info->lmbs[lmb_index++];
405 lmb->base_addr = dr_cell.base_addr;
406 dr_cell.base_addr += drmem_info->lmb_size;
408 lmb->drc_index = dr_cell.drc_index;
411 lmb->aa_index = dr_cell.aa_index;
412 lmb->flags = dr_cell.flags;
419 static int __init drmem_init(void)
421 struct device_node *dn;
424 dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
426 pr_info("No dynamic reconfiguration memory found\n");
430 if (init_drmem_lmb_size(dn)) {
435 prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
437 init_drmem_v1_lmbs(prop);
439 prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
441 init_drmem_v2_lmbs(prop);
447 late_initcall(drmem_init);