xref: /linux/arch/powerpc/mm/drmem.c (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78) 
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 <linux/slab.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 static bool in_drmem_update;
22 
23 u64 drmem_lmb_memory_max(void)
24 {
25 	struct drmem_lmb *last_lmb;
26 
27 	last_lmb = &drmem_info->lmbs[drmem_info->n_lmbs - 1];
28 	return last_lmb->base_addr + drmem_lmb_size();
29 }
30 
31 static u32 drmem_lmb_flags(struct drmem_lmb *lmb)
32 {
33 	/*
34 	 * Return the value of the lmb flags field minus the reserved
35 	 * bit used internally for hotplug processing.
36 	 */
37 	return lmb->flags & ~DRMEM_LMB_RESERVED;
38 }
39 
40 static struct property *clone_property(struct property *prop, u32 prop_sz)
41 {
42 	struct property *new_prop;
43 
44 	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
45 	if (!new_prop)
46 		return NULL;
47 
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);
53 		kfree(new_prop);
54 		return NULL;
55 	}
56 
57 	new_prop->length = prop_sz;
58 #if defined(CONFIG_OF_DYNAMIC)
59 	of_property_set_flag(new_prop, OF_DYNAMIC);
60 #endif
61 	return new_prop;
62 }
63 
64 static int drmem_update_dt_v1(struct device_node *memory,
65 			      struct property *prop)
66 {
67 	struct property *new_prop;
68 	struct of_drconf_cell_v1 *dr_cell;
69 	struct drmem_lmb *lmb;
70 	u32 *p;
71 
72 	new_prop = clone_property(prop, prop->length);
73 	if (!new_prop)
74 		return -1;
75 
76 	p = new_prop->value;
77 	*p++ = cpu_to_be32(drmem_info->n_lmbs);
78 
79 	dr_cell = (struct of_drconf_cell_v1 *)p;
80 
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));
86 
87 		dr_cell++;
88 	}
89 
90 	of_update_property(memory, new_prop);
91 	return 0;
92 }
93 
94 static void init_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
95 				struct drmem_lmb *lmb)
96 {
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));
101 }
102 
103 static int drmem_update_dt_v2(struct device_node *memory,
104 			      struct property *prop)
105 {
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;
110 	u32 *p;
111 
112 	/* First pass, determine how many LMB sets are needed. */
113 	lmb_sets = 0;
114 	prev_lmb = NULL;
115 	for_each_drmem_lmb(lmb) {
116 		if (!prev_lmb) {
117 			prev_lmb = lmb;
118 			lmb_sets++;
119 			continue;
120 		}
121 
122 		if (prev_lmb->aa_index != lmb->aa_index ||
123 		    drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb))
124 			lmb_sets++;
125 
126 		prev_lmb = lmb;
127 	}
128 
129 	prop_sz = lmb_sets * sizeof(*dr_cell) + sizeof(__be32);
130 	new_prop = clone_property(prop, prop_sz);
131 	if (!new_prop)
132 		return -1;
133 
134 	p = new_prop->value;
135 	*p++ = cpu_to_be32(lmb_sets);
136 
137 	dr_cell = (struct of_drconf_cell_v2 *)p;
138 
139 	/* Second pass, populate the LMB set data */
140 	prev_lmb = NULL;
141 	seq_lmbs = 0;
142 	for_each_drmem_lmb(lmb) {
143 		if (prev_lmb == NULL) {
144 			/* Start of first LMB set */
145 			prev_lmb = lmb;
146 			init_drconf_v2_cell(dr_cell, lmb);
147 			seq_lmbs++;
148 			continue;
149 		}
150 
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);
155 			dr_cell++;
156 
157 			init_drconf_v2_cell(dr_cell, lmb);
158 			seq_lmbs = 1;
159 		} else {
160 			seq_lmbs++;
161 		}
162 
163 		prev_lmb = lmb;
164 	}
165 
166 	/* close out last LMB set */
167 	dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
168 	of_update_property(memory, new_prop);
169 	return 0;
170 }
171 
172 int drmem_update_dt(void)
173 {
174 	struct device_node *memory;
175 	struct property *prop;
176 	int rc = -1;
177 
178 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
179 	if (!memory)
180 		return -1;
181 
182 	/*
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.
185 	 */
186 	in_drmem_update = true;
187 	prop = of_find_property(memory, "ibm,dynamic-memory", NULL);
188 	if (prop) {
189 		rc = drmem_update_dt_v1(memory, prop);
190 	} else {
191 		prop = of_find_property(memory, "ibm,dynamic-memory-v2", NULL);
192 		if (prop)
193 			rc = drmem_update_dt_v2(memory, prop);
194 	}
195 	in_drmem_update = false;
196 
197 	of_node_put(memory);
198 	return rc;
199 }
200 
201 static void read_drconf_v1_cell(struct drmem_lmb *lmb,
202 				       const __be32 **prop)
203 {
204 	const __be32 *p = *prop;
205 
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);
209 
210 	p++; /* skip reserved field */
211 
212 	lmb->aa_index = of_read_number(p++, 1);
213 	lmb->flags = of_read_number(p++, 1);
214 
215 	*prop = p;
216 }
217 
218 static int
219 __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm, void *data,
220 		     int (*func)(struct drmem_lmb *, const __be32 **, void *))
221 {
222 	struct drmem_lmb lmb;
223 	u32 i, n_lmbs;
224 	int ret = 0;
225 
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);
230 		if (ret)
231 			break;
232 	}
233 
234 	return ret;
235 }
236 
237 static void read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
238 				       const __be32 **prop)
239 {
240 	const __be32 *p = *prop;
241 
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);
248 
249 	*prop = p;
250 }
251 
252 static int
253 __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm, void *data,
254 		     int (*func)(struct drmem_lmb *, const __be32 **, void *))
255 {
256 	struct of_drconf_cell_v2 dr_cell;
257 	struct drmem_lmb lmb;
258 	u32 i, j, lmb_sets;
259 	int ret = 0;
260 
261 	lmb_sets = of_read_number(prop++, 1);
262 	for (i = 0; i < lmb_sets; i++) {
263 		read_drconf_v2_cell(&dr_cell, &prop);
264 
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();
268 
269 			lmb.drc_index = dr_cell.drc_index;
270 			dr_cell.drc_index++;
271 
272 			lmb.aa_index = dr_cell.aa_index;
273 			lmb.flags = dr_cell.flags;
274 
275 			ret = func(&lmb, &usm, data);
276 			if (ret)
277 				break;
278 		}
279 	}
280 
281 	return ret;
282 }
283 
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 *))
287 {
288 	const __be32 *prop, *usm;
289 	int len, ret = -ENODEV;
290 
291 	prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
292 	if (!prop || len < dt_root_size_cells * sizeof(__be32))
293 		return ret;
294 
295 	/* Get the address & size cells */
296 	n_root_addr_cells = dt_root_addr_cells;
297 	n_root_size_cells = dt_root_size_cells;
298 
299 	drmem_info->lmb_size = dt_mem_next_cell(dt_root_size_cells, &prop);
300 
301 	usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory", &len);
302 
303 	prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &len);
304 	if (prop) {
305 		ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
306 	} else {
307 		prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory-v2",
308 					   &len);
309 		if (prop)
310 			ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
311 	}
312 
313 	memblock_dump_all();
314 	return ret;
315 }
316 
317 /*
318  * Update the LMB associativity index.
319  */
320 static int update_lmb(struct drmem_lmb *updated_lmb,
321 		      __maybe_unused const __be32 **usm,
322 		      __maybe_unused void *data)
323 {
324 	struct drmem_lmb *lmb;
325 
326 	for_each_drmem_lmb(lmb) {
327 		if (lmb->drc_index != updated_lmb->drc_index)
328 			continue;
329 
330 		lmb->aa_index = updated_lmb->aa_index;
331 		break;
332 	}
333 	return 0;
334 }
335 
336 /*
337  * Update the LMB associativity index.
338  *
339  * This needs to be called when the hypervisor is updating the
340  * dynamic-reconfiguration-memory node property.
341  */
342 void drmem_update_lmbs(struct property *prop)
343 {
344 	/*
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.
348 	 */
349 	if (in_drmem_update)
350 		return;
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);
355 }
356 #endif
357 
358 static int init_drmem_lmb_size(struct device_node *dn)
359 {
360 	const __be32 *prop;
361 	int len;
362 
363 	if (drmem_info->lmb_size)
364 		return 0;
365 
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");
369 		return -1;
370 	}
371 
372 	drmem_info->lmb_size = of_read_number(prop, n_root_size_cells);
373 	return 0;
374 }
375 
376 /*
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)
380  */
381 static const __be32 *of_get_usable_memory(struct device_node *dn)
382 {
383 	const __be32 *prop;
384 	u32 len;
385 
386 	prop = of_get_property(dn, "linux,drconf-usable-memory", &len);
387 	if (!prop || len < sizeof(unsigned int))
388 		return NULL;
389 
390 	return prop;
391 }
392 
393 int walk_drmem_lmbs(struct device_node *dn, void *data,
394 		    int (*func)(struct drmem_lmb *, const __be32 **, void *))
395 {
396 	const __be32 *prop, *usm;
397 	int ret = -ENODEV;
398 
399 	if (!of_root)
400 		return ret;
401 
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);
407 
408 	if (init_drmem_lmb_size(dn))
409 		return ret;
410 
411 	usm = of_get_usable_memory(dn);
412 
413 	prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
414 	if (prop) {
415 		ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
416 	} else {
417 		prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
418 		if (prop)
419 			ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
420 	}
421 
422 	return ret;
423 }
424 
425 static void __init init_drmem_v1_lmbs(const __be32 *prop)
426 {
427 	struct drmem_lmb *lmb;
428 
429 	drmem_info->n_lmbs = of_read_number(prop++, 1);
430 	if (drmem_info->n_lmbs == 0)
431 		return;
432 
433 	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
434 				   GFP_KERNEL);
435 	if (!drmem_info->lmbs)
436 		return;
437 
438 	for_each_drmem_lmb(lmb)
439 		read_drconf_v1_cell(lmb, &prop);
440 }
441 
442 static void __init init_drmem_v2_lmbs(const __be32 *prop)
443 {
444 	struct drmem_lmb *lmb;
445 	struct of_drconf_cell_v2 dr_cell;
446 	const __be32 *p;
447 	u32 i, j, lmb_sets;
448 	int lmb_index;
449 
450 	lmb_sets = of_read_number(prop++, 1);
451 	if (lmb_sets == 0)
452 		return;
453 
454 	/* first pass, calculate the number of LMBs */
455 	p = prop;
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;
459 	}
460 
461 	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
462 				   GFP_KERNEL);
463 	if (!drmem_info->lmbs)
464 		return;
465 
466 	/* second pass, read in the LMB information */
467 	lmb_index = 0;
468 	p = prop;
469 
470 	for (i = 0; i < lmb_sets; i++) {
471 		read_drconf_v2_cell(&dr_cell, &p);
472 
473 		for (j = 0; j < dr_cell.seq_lmbs; j++) {
474 			lmb = &drmem_info->lmbs[lmb_index++];
475 
476 			lmb->base_addr = dr_cell.base_addr;
477 			dr_cell.base_addr += drmem_info->lmb_size;
478 
479 			lmb->drc_index = dr_cell.drc_index;
480 			dr_cell.drc_index++;
481 
482 			lmb->aa_index = dr_cell.aa_index;
483 			lmb->flags = dr_cell.flags;
484 		}
485 	}
486 }
487 
488 static int __init drmem_init(void)
489 {
490 	struct device_node *dn;
491 	const __be32 *prop;
492 
493 	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
494 	if (!dn) {
495 		pr_info("No dynamic reconfiguration memory found\n");
496 		return 0;
497 	}
498 
499 	if (init_drmem_lmb_size(dn)) {
500 		of_node_put(dn);
501 		return 0;
502 	}
503 
504 	prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
505 	if (prop) {
506 		init_drmem_v1_lmbs(prop);
507 	} else {
508 		prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
509 		if (prop)
510 			init_drmem_v2_lmbs(prop);
511 	}
512 
513 	of_node_put(dn);
514 	return 0;
515 }
516 late_initcall(drmem_init);
517