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 struct drmem_lmb_info __drmem_info;
18 struct drmem_lmb_info *drmem_info = &__drmem_info;
19
drmem_lmb_memory_max(void)20 u64 drmem_lmb_memory_max(void)
21 {
22 struct drmem_lmb *last_lmb;
23
24 last_lmb = &drmem_info->lmbs[drmem_info->n_lmbs - 1];
25 return last_lmb->base_addr + drmem_lmb_size();
26 }
27
drmem_lmb_flags(struct drmem_lmb * lmb)28 static u32 drmem_lmb_flags(struct drmem_lmb *lmb)
29 {
30 /*
31 * Return the value of the lmb flags field minus the reserved
32 * bit used internally for hotplug processing.
33 */
34 return lmb->flags & ~DRMEM_LMB_RESERVED;
35 }
36
clone_property(struct property * prop,u32 prop_sz)37 static struct property *clone_property(struct property *prop, u32 prop_sz)
38 {
39 struct property *new_prop;
40
41 new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
42 if (!new_prop)
43 return NULL;
44
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);
50 kfree(new_prop);
51 return NULL;
52 }
53
54 new_prop->length = prop_sz;
55 #if defined(CONFIG_OF_DYNAMIC)
56 of_property_set_flag(new_prop, OF_DYNAMIC);
57 #endif
58 return new_prop;
59 }
60
drmem_update_dt_v1(struct device_node * memory,struct property * prop)61 static int drmem_update_dt_v1(struct device_node *memory,
62 struct property *prop)
63 {
64 struct property *new_prop;
65 struct of_drconf_cell_v1 *dr_cell;
66 struct drmem_lmb *lmb;
67 u32 *p;
68
69 new_prop = clone_property(prop, prop->length);
70 if (!new_prop)
71 return -1;
72
73 p = new_prop->value;
74 *p++ = cpu_to_be32(drmem_info->n_lmbs);
75
76 dr_cell = (struct of_drconf_cell_v1 *)p;
77
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));
83
84 dr_cell++;
85 }
86
87 of_update_property(memory, new_prop);
88 return 0;
89 }
90
init_drconf_v2_cell(struct of_drconf_cell_v2 * dr_cell,struct drmem_lmb * lmb)91 static void init_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
92 struct drmem_lmb *lmb)
93 {
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));
98 }
99
drmem_update_dt_v2(struct device_node * memory,struct property * prop)100 static int drmem_update_dt_v2(struct device_node *memory,
101 struct property *prop)
102 {
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;
107 u32 *p;
108
109 /* First pass, determine how many LMB sets are needed. */
110 lmb_sets = 0;
111 prev_lmb = NULL;
112 for_each_drmem_lmb(lmb) {
113 if (!prev_lmb) {
114 prev_lmb = lmb;
115 lmb_sets++;
116 continue;
117 }
118
119 if (prev_lmb->aa_index != lmb->aa_index ||
120 drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb))
121 lmb_sets++;
122
123 prev_lmb = lmb;
124 }
125
126 prop_sz = lmb_sets * sizeof(*dr_cell) + sizeof(__be32);
127 new_prop = clone_property(prop, prop_sz);
128 if (!new_prop)
129 return -1;
130
131 p = new_prop->value;
132 *p++ = cpu_to_be32(lmb_sets);
133
134 dr_cell = (struct of_drconf_cell_v2 *)p;
135
136 /* Second pass, populate the LMB set data */
137 prev_lmb = NULL;
138 seq_lmbs = 0;
139 for_each_drmem_lmb(lmb) {
140 if (prev_lmb == NULL) {
141 /* Start of first LMB set */
142 prev_lmb = lmb;
143 init_drconf_v2_cell(dr_cell, lmb);
144 seq_lmbs++;
145 continue;
146 }
147
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);
152 dr_cell++;
153
154 init_drconf_v2_cell(dr_cell, lmb);
155 seq_lmbs = 1;
156 } else {
157 seq_lmbs++;
158 }
159
160 prev_lmb = lmb;
161 }
162
163 /* close out last LMB set */
164 dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
165 of_update_property(memory, new_prop);
166 return 0;
167 }
168
drmem_update_dt(void)169 int drmem_update_dt(void)
170 {
171 struct device_node *memory;
172 struct property *prop;
173 int rc = -1;
174
175 memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
176 if (!memory)
177 return -1;
178
179 prop = of_find_property(memory, "ibm,dynamic-memory", NULL);
180 if (prop) {
181 rc = drmem_update_dt_v1(memory, prop);
182 } else {
183 prop = of_find_property(memory, "ibm,dynamic-memory-v2", NULL);
184 if (prop)
185 rc = drmem_update_dt_v2(memory, prop);
186 }
187
188 of_node_put(memory);
189 return rc;
190 }
191
read_drconf_v1_cell(struct drmem_lmb * lmb,const __be32 ** prop)192 static void __init read_drconf_v1_cell(struct drmem_lmb *lmb,
193 const __be32 **prop)
194 {
195 const __be32 *p = *prop;
196
197 lmb->base_addr = dt_mem_next_cell(dt_root_addr_cells, &p);
198 lmb->drc_index = of_read_number(p++, 1);
199
200 p++; /* skip reserved field */
201
202 lmb->aa_index = of_read_number(p++, 1);
203 lmb->flags = of_read_number(p++, 1);
204
205 *prop = p;
206 }
207
__walk_drmem_v1_lmbs(const __be32 * prop,const __be32 * usm,void (* func)(struct drmem_lmb *,const __be32 **))208 static void __init __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm,
209 void (*func)(struct drmem_lmb *, const __be32 **))
210 {
211 struct drmem_lmb lmb;
212 u32 i, n_lmbs;
213
214 n_lmbs = of_read_number(prop++, 1);
215 if (n_lmbs == 0)
216 return;
217
218 for (i = 0; i < n_lmbs; i++) {
219 read_drconf_v1_cell(&lmb, &prop);
220 func(&lmb, &usm);
221 }
222 }
223
read_drconf_v2_cell(struct of_drconf_cell_v2 * dr_cell,const __be32 ** prop)224 static void __init read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
225 const __be32 **prop)
226 {
227 const __be32 *p = *prop;
228
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);
234
235 *prop = p;
236 }
237
__walk_drmem_v2_lmbs(const __be32 * prop,const __be32 * usm,void (* func)(struct drmem_lmb *,const __be32 **))238 static void __init __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm,
239 void (*func)(struct drmem_lmb *, const __be32 **))
240 {
241 struct of_drconf_cell_v2 dr_cell;
242 struct drmem_lmb lmb;
243 u32 i, j, lmb_sets;
244
245 lmb_sets = of_read_number(prop++, 1);
246 if (lmb_sets == 0)
247 return;
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
walk_drmem_lmbs_early(unsigned long node,void (* func)(struct drmem_lmb *,const __be32 **))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
init_drmem_lmb_size(struct device_node * dn)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 */
of_get_usable_memory(struct device_node * dn)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
walk_drmem_lmbs(struct device_node * dn,void (* func)(struct drmem_lmb *,const __be32 **))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
init_drmem_v1_lmbs(const __be32 * prop)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 if (drmem_info->n_lmbs == 0)
358 return;
359
360 drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
361 GFP_KERNEL);
362 if (!drmem_info->lmbs)
363 return;
364
365 for_each_drmem_lmb(lmb) {
366 read_drconf_v1_cell(lmb, &prop);
367 lmb_set_nid(lmb);
368 }
369 }
370
init_drmem_v2_lmbs(const __be32 * prop)371 static void __init init_drmem_v2_lmbs(const __be32 *prop)
372 {
373 struct drmem_lmb *lmb;
374 struct of_drconf_cell_v2 dr_cell;
375 const __be32 *p;
376 u32 i, j, lmb_sets;
377 int lmb_index;
378
379 lmb_sets = of_read_number(prop++, 1);
380 if (lmb_sets == 0)
381 return;
382
383 /* first pass, calculate the number of LMBs */
384 p = prop;
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;
388 }
389
390 drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
391 GFP_KERNEL);
392 if (!drmem_info->lmbs)
393 return;
394
395 /* second pass, read in the LMB information */
396 lmb_index = 0;
397 p = prop;
398
399 for (i = 0; i < lmb_sets; i++) {
400 read_drconf_v2_cell(&dr_cell, &p);
401
402 for (j = 0; j < dr_cell.seq_lmbs; j++) {
403 lmb = &drmem_info->lmbs[lmb_index++];
404
405 lmb->base_addr = dr_cell.base_addr;
406 dr_cell.base_addr += drmem_info->lmb_size;
407
408 lmb->drc_index = dr_cell.drc_index;
409 dr_cell.drc_index++;
410
411 lmb->aa_index = dr_cell.aa_index;
412 lmb->flags = dr_cell.flags;
413
414 lmb_set_nid(lmb);
415 }
416 }
417 }
418
drmem_init(void)419 static int __init drmem_init(void)
420 {
421 struct device_node *dn;
422 const __be32 *prop;
423
424 dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
425 if (!dn) {
426 pr_info("No dynamic reconfiguration memory found\n");
427 return 0;
428 }
429
430 if (init_drmem_lmb_size(dn)) {
431 of_node_put(dn);
432 return 0;
433 }
434
435 prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
436 if (prop) {
437 init_drmem_v1_lmbs(prop);
438 } else {
439 prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
440 if (prop)
441 init_drmem_v2_lmbs(prop);
442 }
443
444 of_node_put(dn);
445 return 0;
446 }
447 late_initcall(drmem_init);
448
