1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * pseries Memory Hotplug infrastructure.
4  *
5  * Copyright (C) 2008 Badari Pulavarty, IBM Corporation
6  */
7 
8 #define pr_fmt(fmt)	"pseries-hotplug-mem: " fmt
9 
10 #include <linux/of.h>
11 #include <linux/of_address.h>
12 #include <linux/memblock.h>
13 #include <linux/memory.h>
14 #include <linux/memory_hotplug.h>
15 #include <linux/slab.h>
16 
17 #include <asm/firmware.h>
18 #include <asm/machdep.h>
19 #include <asm/sparsemem.h>
20 #include <asm/fadump.h>
21 #include <asm/drmem.h>
22 #include "pseries.h"
23 
dlpar_free_property(struct property * prop)24 static void dlpar_free_property(struct property *prop)
25 {
26 	kfree(prop->name);
27 	kfree(prop->value);
28 	kfree(prop);
29 }
30 
dlpar_clone_property(struct property * prop,u32 prop_size)31 static struct property *dlpar_clone_property(struct property *prop,
32 					     u32 prop_size)
33 {
34 	struct property *new_prop;
35 
36 	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
37 	if (!new_prop)
38 		return NULL;
39 
40 	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
41 	new_prop->value = kzalloc(prop_size, GFP_KERNEL);
42 	if (!new_prop->name || !new_prop->value) {
43 		dlpar_free_property(new_prop);
44 		return NULL;
45 	}
46 
47 	memcpy(new_prop->value, prop->value, prop->length);
48 	new_prop->length = prop_size;
49 
50 	of_property_set_flag(new_prop, OF_DYNAMIC);
51 	return new_prop;
52 }
53 
find_aa_index(struct device_node * dr_node,struct property * ala_prop,const u32 * lmb_assoc,u32 * aa_index)54 static bool find_aa_index(struct device_node *dr_node,
55 			 struct property *ala_prop,
56 			 const u32 *lmb_assoc, u32 *aa_index)
57 {
58 	u32 *assoc_arrays, new_prop_size;
59 	struct property *new_prop;
60 	int aa_arrays, aa_array_entries, aa_array_sz;
61 	int i, index;
62 
63 	/*
64 	 * The ibm,associativity-lookup-arrays property is defined to be
65 	 * a 32-bit value specifying the number of associativity arrays
66 	 * followed by a 32-bitvalue specifying the number of entries per
67 	 * array, followed by the associativity arrays.
68 	 */
69 	assoc_arrays = ala_prop->value;
70 
71 	aa_arrays = be32_to_cpu(assoc_arrays[0]);
72 	aa_array_entries = be32_to_cpu(assoc_arrays[1]);
73 	aa_array_sz = aa_array_entries * sizeof(u32);
74 
75 	for (i = 0; i < aa_arrays; i++) {
76 		index = (i * aa_array_entries) + 2;
77 
78 		if (memcmp(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz))
79 			continue;
80 
81 		*aa_index = i;
82 		return true;
83 	}
84 
85 	new_prop_size = ala_prop->length + aa_array_sz;
86 	new_prop = dlpar_clone_property(ala_prop, new_prop_size);
87 	if (!new_prop)
88 		return false;
89 
90 	assoc_arrays = new_prop->value;
91 
92 	/* increment the number of entries in the lookup array */
93 	assoc_arrays[0] = cpu_to_be32(aa_arrays + 1);
94 
95 	/* copy the new associativity into the lookup array */
96 	index = aa_arrays * aa_array_entries + 2;
97 	memcpy(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz);
98 
99 	of_update_property(dr_node, new_prop);
100 
101 	/*
102 	 * The associativity lookup array index for this lmb is
103 	 * number of entries - 1 since we added its associativity
104 	 * to the end of the lookup array.
105 	 */
106 	*aa_index = be32_to_cpu(assoc_arrays[0]) - 1;
107 	return true;
108 }
109 
update_lmb_associativity_index(struct drmem_lmb * lmb)110 static int update_lmb_associativity_index(struct drmem_lmb *lmb)
111 {
112 	struct device_node *parent, *lmb_node, *dr_node;
113 	struct property *ala_prop;
114 	const u32 *lmb_assoc;
115 	u32 aa_index;
116 	bool found;
117 
118 	parent = of_find_node_by_path("/");
119 	if (!parent)
120 		return -ENODEV;
121 
122 	lmb_node = dlpar_configure_connector(cpu_to_be32(lmb->drc_index),
123 					     parent);
124 	of_node_put(parent);
125 	if (!lmb_node)
126 		return -EINVAL;
127 
128 	lmb_assoc = of_get_property(lmb_node, "ibm,associativity", NULL);
129 	if (!lmb_assoc) {
130 		dlpar_free_cc_nodes(lmb_node);
131 		return -ENODEV;
132 	}
133 
134 	update_numa_distance(lmb_node);
135 
136 	dr_node = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
137 	if (!dr_node) {
138 		dlpar_free_cc_nodes(lmb_node);
139 		return -ENODEV;
140 	}
141 
142 	ala_prop = of_find_property(dr_node, "ibm,associativity-lookup-arrays",
143 				    NULL);
144 	if (!ala_prop) {
145 		of_node_put(dr_node);
146 		dlpar_free_cc_nodes(lmb_node);
147 		return -ENODEV;
148 	}
149 
150 	found = find_aa_index(dr_node, ala_prop, lmb_assoc, &aa_index);
151 
152 	of_node_put(dr_node);
153 	dlpar_free_cc_nodes(lmb_node);
154 
155 	if (!found) {
156 		pr_err("Could not find LMB associativity\n");
157 		return -1;
158 	}
159 
160 	lmb->aa_index = aa_index;
161 	return 0;
162 }
163 
lmb_to_memblock(struct drmem_lmb * lmb)164 static struct memory_block *lmb_to_memblock(struct drmem_lmb *lmb)
165 {
166 	unsigned long section_nr;
167 	struct memory_block *mem_block;
168 
169 	section_nr = pfn_to_section_nr(PFN_DOWN(lmb->base_addr));
170 
171 	mem_block = find_memory_block(section_nr);
172 	return mem_block;
173 }
174 
get_lmb_range(u32 drc_index,int n_lmbs,struct drmem_lmb ** start_lmb,struct drmem_lmb ** end_lmb)175 static int get_lmb_range(u32 drc_index, int n_lmbs,
176 			 struct drmem_lmb **start_lmb,
177 			 struct drmem_lmb **end_lmb)
178 {
179 	struct drmem_lmb *lmb, *start, *end;
180 	struct drmem_lmb *limit;
181 
182 	start = NULL;
183 	for_each_drmem_lmb(lmb) {
184 		if (lmb->drc_index == drc_index) {
185 			start = lmb;
186 			break;
187 		}
188 	}
189 
190 	if (!start)
191 		return -EINVAL;
192 
193 	end = &start[n_lmbs];
194 
195 	limit = &drmem_info->lmbs[drmem_info->n_lmbs];
196 	if (end > limit)
197 		return -EINVAL;
198 
199 	*start_lmb = start;
200 	*end_lmb = end;
201 	return 0;
202 }
203 
dlpar_change_lmb_state(struct drmem_lmb * lmb,bool online)204 static int dlpar_change_lmb_state(struct drmem_lmb *lmb, bool online)
205 {
206 	struct memory_block *mem_block;
207 	int rc;
208 
209 	mem_block = lmb_to_memblock(lmb);
210 	if (!mem_block)
211 		return -EINVAL;
212 
213 	if (online && mem_block->dev.offline)
214 		rc = device_online(&mem_block->dev);
215 	else if (!online && !mem_block->dev.offline)
216 		rc = device_offline(&mem_block->dev);
217 	else
218 		rc = 0;
219 
220 	put_device(&mem_block->dev);
221 
222 	return rc;
223 }
224 
dlpar_online_lmb(struct drmem_lmb * lmb)225 static int dlpar_online_lmb(struct drmem_lmb *lmb)
226 {
227 	return dlpar_change_lmb_state(lmb, true);
228 }
229 
230 #ifdef CONFIG_MEMORY_HOTREMOVE
dlpar_offline_lmb(struct drmem_lmb * lmb)231 static int dlpar_offline_lmb(struct drmem_lmb *lmb)
232 {
233 	return dlpar_change_lmb_state(lmb, false);
234 }
235 
pseries_remove_memblock(unsigned long base,unsigned long memblock_size)236 static int pseries_remove_memblock(unsigned long base, unsigned long memblock_size)
237 {
238 	unsigned long start_pfn;
239 	int sections_per_block;
240 	int i;
241 
242 	start_pfn = base >> PAGE_SHIFT;
243 
244 	lock_device_hotplug();
245 
246 	if (!pfn_valid(start_pfn))
247 		goto out;
248 
249 	sections_per_block = memory_block_size / MIN_MEMORY_BLOCK_SIZE;
250 
251 	for (i = 0; i < sections_per_block; i++) {
252 		__remove_memory(base, MIN_MEMORY_BLOCK_SIZE);
253 		base += MIN_MEMORY_BLOCK_SIZE;
254 	}
255 
256 out:
257 	/* Update memory regions for memory remove */
258 	memblock_remove(base, memblock_size);
259 	unlock_device_hotplug();
260 	return 0;
261 }
262 
pseries_remove_mem_node(struct device_node * np)263 static int pseries_remove_mem_node(struct device_node *np)
264 {
265 	int ret;
266 	struct resource res;
267 
268 	/*
269 	 * Check to see if we are actually removing memory
270 	 */
271 	if (!of_node_is_type(np, "memory"))
272 		return 0;
273 
274 	/*
275 	 * Find the base address and size of the memblock
276 	 */
277 	ret = of_address_to_resource(np, 0, &res);
278 	if (ret)
279 		return ret;
280 
281 	pseries_remove_memblock(res.start, resource_size(&res));
282 	return 0;
283 }
284 
lmb_is_removable(struct drmem_lmb * lmb)285 static bool lmb_is_removable(struct drmem_lmb *lmb)
286 {
287 	if ((lmb->flags & DRCONF_MEM_RESERVED) ||
288 		!(lmb->flags & DRCONF_MEM_ASSIGNED))
289 		return false;
290 
291 #ifdef CONFIG_FA_DUMP
292 	/*
293 	 * Don't hot-remove memory that falls in fadump boot memory area
294 	 * and memory that is reserved for capturing old kernel memory.
295 	 */
296 	if (is_fadump_memory_area(lmb->base_addr, memory_block_size_bytes()))
297 		return false;
298 #endif
299 	/* device_offline() will determine if we can actually remove this lmb */
300 	return true;
301 }
302 
303 static int dlpar_add_lmb(struct drmem_lmb *);
304 
dlpar_remove_lmb(struct drmem_lmb * lmb)305 static int dlpar_remove_lmb(struct drmem_lmb *lmb)
306 {
307 	struct memory_block *mem_block;
308 	int rc;
309 
310 	if (!lmb_is_removable(lmb))
311 		return -EINVAL;
312 
313 	mem_block = lmb_to_memblock(lmb);
314 	if (mem_block == NULL)
315 		return -EINVAL;
316 
317 	rc = dlpar_offline_lmb(lmb);
318 	if (rc) {
319 		put_device(&mem_block->dev);
320 		return rc;
321 	}
322 
323 	__remove_memory(lmb->base_addr, memory_block_size);
324 	put_device(&mem_block->dev);
325 
326 	/* Update memory regions for memory remove */
327 	memblock_remove(lmb->base_addr, memory_block_size);
328 
329 	invalidate_lmb_associativity_index(lmb);
330 	lmb->flags &= ~DRCONF_MEM_ASSIGNED;
331 
332 	return 0;
333 }
334 
dlpar_memory_remove_by_count(u32 lmbs_to_remove)335 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
336 {
337 	struct drmem_lmb *lmb;
338 	int lmbs_reserved = 0;
339 	int lmbs_available = 0;
340 	int rc;
341 
342 	pr_info("Attempting to hot-remove %d LMB(s)\n", lmbs_to_remove);
343 
344 	if (lmbs_to_remove == 0)
345 		return -EINVAL;
346 
347 	/* Validate that there are enough LMBs to satisfy the request */
348 	for_each_drmem_lmb(lmb) {
349 		if (lmb_is_removable(lmb))
350 			lmbs_available++;
351 
352 		if (lmbs_available == lmbs_to_remove)
353 			break;
354 	}
355 
356 	if (lmbs_available < lmbs_to_remove) {
357 		pr_info("Not enough LMBs available (%d of %d) to satisfy request\n",
358 			lmbs_available, lmbs_to_remove);
359 		return -EINVAL;
360 	}
361 
362 	for_each_drmem_lmb(lmb) {
363 		rc = dlpar_remove_lmb(lmb);
364 		if (rc)
365 			continue;
366 
367 		/* Mark this lmb so we can add it later if all of the
368 		 * requested LMBs cannot be removed.
369 		 */
370 		drmem_mark_lmb_reserved(lmb);
371 
372 		lmbs_reserved++;
373 		if (lmbs_reserved == lmbs_to_remove)
374 			break;
375 	}
376 
377 	if (lmbs_reserved != lmbs_to_remove) {
378 		pr_err("Memory hot-remove failed, adding LMB's back\n");
379 
380 		for_each_drmem_lmb(lmb) {
381 			if (!drmem_lmb_reserved(lmb))
382 				continue;
383 
384 			rc = dlpar_add_lmb(lmb);
385 			if (rc)
386 				pr_err("Failed to add LMB back, drc index %x\n",
387 				       lmb->drc_index);
388 
389 			drmem_remove_lmb_reservation(lmb);
390 
391 			lmbs_reserved--;
392 			if (lmbs_reserved == 0)
393 				break;
394 		}
395 
396 		rc = -EINVAL;
397 	} else {
398 		for_each_drmem_lmb(lmb) {
399 			if (!drmem_lmb_reserved(lmb))
400 				continue;
401 
402 			dlpar_release_drc(lmb->drc_index);
403 			pr_info("Memory at %llx was hot-removed\n",
404 				lmb->base_addr);
405 
406 			drmem_remove_lmb_reservation(lmb);
407 
408 			lmbs_reserved--;
409 			if (lmbs_reserved == 0)
410 				break;
411 		}
412 		rc = 0;
413 	}
414 
415 	return rc;
416 }
417 
dlpar_memory_remove_by_index(u32 drc_index)418 static int dlpar_memory_remove_by_index(u32 drc_index)
419 {
420 	struct drmem_lmb *lmb;
421 	int lmb_found;
422 	int rc;
423 
424 	pr_debug("Attempting to hot-remove LMB, drc index %x\n", drc_index);
425 
426 	lmb_found = 0;
427 	for_each_drmem_lmb(lmb) {
428 		if (lmb->drc_index == drc_index) {
429 			lmb_found = 1;
430 			rc = dlpar_remove_lmb(lmb);
431 			if (!rc)
432 				dlpar_release_drc(lmb->drc_index);
433 
434 			break;
435 		}
436 	}
437 
438 	if (!lmb_found) {
439 		pr_debug("Failed to look up LMB for drc index %x\n", drc_index);
440 		rc = -EINVAL;
441 	} else if (rc) {
442 		pr_debug("Failed to hot-remove memory at %llx\n",
443 			 lmb->base_addr);
444 	} else {
445 		pr_debug("Memory at %llx was hot-removed\n", lmb->base_addr);
446 	}
447 
448 	return rc;
449 }
450 
dlpar_memory_remove_by_ic(u32 lmbs_to_remove,u32 drc_index)451 static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
452 {
453 	struct drmem_lmb *lmb, *start_lmb, *end_lmb;
454 	int rc;
455 
456 	pr_info("Attempting to hot-remove %u LMB(s) at %x\n",
457 		lmbs_to_remove, drc_index);
458 
459 	if (lmbs_to_remove == 0)
460 		return -EINVAL;
461 
462 	rc = get_lmb_range(drc_index, lmbs_to_remove, &start_lmb, &end_lmb);
463 	if (rc)
464 		return -EINVAL;
465 
466 	/*
467 	 * Validate that all LMBs in range are not reserved. Note that it
468 	 * is ok if they are !ASSIGNED since our goal here is to remove the
469 	 * LMB range, regardless of whether some LMBs were already removed
470 	 * by any other reason.
471 	 *
472 	 * This is a contrast to what is done in remove_by_count() where we
473 	 * check for both RESERVED and !ASSIGNED (via lmb_is_removable()),
474 	 * because we want to remove a fixed amount of LMBs in that function.
475 	 */
476 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
477 		if (lmb->flags & DRCONF_MEM_RESERVED) {
478 			pr_err("Memory at %llx (drc index %x) is reserved\n",
479 				lmb->base_addr, lmb->drc_index);
480 			return -EINVAL;
481 		}
482 	}
483 
484 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
485 		/*
486 		 * dlpar_remove_lmb() will error out if the LMB is already
487 		 * !ASSIGNED, but this case is a no-op for us.
488 		 */
489 		if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
490 			continue;
491 
492 		rc = dlpar_remove_lmb(lmb);
493 		if (rc)
494 			break;
495 
496 		drmem_mark_lmb_reserved(lmb);
497 	}
498 
499 	if (rc) {
500 		pr_err("Memory indexed-count-remove failed, adding any removed LMBs\n");
501 
502 
503 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
504 			if (!drmem_lmb_reserved(lmb))
505 				continue;
506 
507 			/*
508 			 * Setting the isolation state of an UNISOLATED/CONFIGURED
509 			 * device to UNISOLATE is a no-op, but the hypervisor can
510 			 * use it as a hint that the LMB removal failed.
511 			 */
512 			dlpar_unisolate_drc(lmb->drc_index);
513 
514 			rc = dlpar_add_lmb(lmb);
515 			if (rc)
516 				pr_err("Failed to add LMB, drc index %x\n",
517 				       lmb->drc_index);
518 
519 			drmem_remove_lmb_reservation(lmb);
520 		}
521 		rc = -EINVAL;
522 	} else {
523 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
524 			if (!drmem_lmb_reserved(lmb))
525 				continue;
526 
527 			dlpar_release_drc(lmb->drc_index);
528 			pr_info("Memory at %llx (drc index %x) was hot-removed\n",
529 				lmb->base_addr, lmb->drc_index);
530 
531 			drmem_remove_lmb_reservation(lmb);
532 		}
533 	}
534 
535 	return rc;
536 }
537 
538 #else
pseries_remove_memblock(unsigned long base,unsigned long memblock_size)539 static inline int pseries_remove_memblock(unsigned long base,
540 					  unsigned long memblock_size)
541 {
542 	return -EOPNOTSUPP;
543 }
pseries_remove_mem_node(struct device_node * np)544 static inline int pseries_remove_mem_node(struct device_node *np)
545 {
546 	return 0;
547 }
dlpar_remove_lmb(struct drmem_lmb * lmb)548 static int dlpar_remove_lmb(struct drmem_lmb *lmb)
549 {
550 	return -EOPNOTSUPP;
551 }
dlpar_memory_remove_by_count(u32 lmbs_to_remove)552 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
553 {
554 	return -EOPNOTSUPP;
555 }
dlpar_memory_remove_by_index(u32 drc_index)556 static int dlpar_memory_remove_by_index(u32 drc_index)
557 {
558 	return -EOPNOTSUPP;
559 }
560 
dlpar_memory_remove_by_ic(u32 lmbs_to_remove,u32 drc_index)561 static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
562 {
563 	return -EOPNOTSUPP;
564 }
565 #endif /* CONFIG_MEMORY_HOTREMOVE */
566 
dlpar_add_lmb(struct drmem_lmb * lmb)567 static int dlpar_add_lmb(struct drmem_lmb *lmb)
568 {
569 	unsigned long block_sz;
570 	int nid, rc;
571 
572 	if (lmb->flags & DRCONF_MEM_ASSIGNED)
573 		return -EINVAL;
574 
575 	rc = update_lmb_associativity_index(lmb);
576 	if (rc) {
577 		dlpar_release_drc(lmb->drc_index);
578 		return rc;
579 	}
580 
581 	block_sz = memory_block_size_bytes();
582 
583 	/* Find the node id for this LMB.  Fake one if necessary. */
584 	nid = of_drconf_to_nid_single(lmb);
585 	if (nid < 0 || !node_possible(nid))
586 		nid = first_online_node;
587 
588 	/* Add the memory */
589 	rc = __add_memory(nid, lmb->base_addr, block_sz, MHP_MEMMAP_ON_MEMORY);
590 	if (rc) {
591 		invalidate_lmb_associativity_index(lmb);
592 		return rc;
593 	}
594 
595 	rc = dlpar_online_lmb(lmb);
596 	if (rc) {
597 		__remove_memory(lmb->base_addr, block_sz);
598 		invalidate_lmb_associativity_index(lmb);
599 	} else {
600 		lmb->flags |= DRCONF_MEM_ASSIGNED;
601 	}
602 
603 	return rc;
604 }
605 
dlpar_memory_add_by_count(u32 lmbs_to_add)606 static int dlpar_memory_add_by_count(u32 lmbs_to_add)
607 {
608 	struct drmem_lmb *lmb;
609 	int lmbs_available = 0;
610 	int lmbs_reserved = 0;
611 	int rc;
612 
613 	pr_info("Attempting to hot-add %d LMB(s)\n", lmbs_to_add);
614 
615 	if (lmbs_to_add == 0)
616 		return -EINVAL;
617 
618 	/* Validate that there are enough LMBs to satisfy the request */
619 	for_each_drmem_lmb(lmb) {
620 		if (lmb->flags & DRCONF_MEM_RESERVED)
621 			continue;
622 
623 		if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
624 			lmbs_available++;
625 
626 		if (lmbs_available == lmbs_to_add)
627 			break;
628 	}
629 
630 	if (lmbs_available < lmbs_to_add)
631 		return -EINVAL;
632 
633 	for_each_drmem_lmb(lmb) {
634 		if (lmb->flags & DRCONF_MEM_ASSIGNED)
635 			continue;
636 
637 		rc = dlpar_acquire_drc(lmb->drc_index);
638 		if (rc)
639 			continue;
640 
641 		rc = dlpar_add_lmb(lmb);
642 		if (rc) {
643 			dlpar_release_drc(lmb->drc_index);
644 			continue;
645 		}
646 
647 		/* Mark this lmb so we can remove it later if all of the
648 		 * requested LMBs cannot be added.
649 		 */
650 		drmem_mark_lmb_reserved(lmb);
651 		lmbs_reserved++;
652 		if (lmbs_reserved == lmbs_to_add)
653 			break;
654 	}
655 
656 	if (lmbs_reserved != lmbs_to_add) {
657 		pr_err("Memory hot-add failed, removing any added LMBs\n");
658 
659 		for_each_drmem_lmb(lmb) {
660 			if (!drmem_lmb_reserved(lmb))
661 				continue;
662 
663 			rc = dlpar_remove_lmb(lmb);
664 			if (rc)
665 				pr_err("Failed to remove LMB, drc index %x\n",
666 				       lmb->drc_index);
667 			else
668 				dlpar_release_drc(lmb->drc_index);
669 
670 			drmem_remove_lmb_reservation(lmb);
671 			lmbs_reserved--;
672 
673 			if (lmbs_reserved == 0)
674 				break;
675 		}
676 		rc = -EINVAL;
677 	} else {
678 		for_each_drmem_lmb(lmb) {
679 			if (!drmem_lmb_reserved(lmb))
680 				continue;
681 
682 			pr_debug("Memory at %llx (drc index %x) was hot-added\n",
683 				 lmb->base_addr, lmb->drc_index);
684 			drmem_remove_lmb_reservation(lmb);
685 			lmbs_reserved--;
686 
687 			if (lmbs_reserved == 0)
688 				break;
689 		}
690 		rc = 0;
691 	}
692 
693 	return rc;
694 }
695 
dlpar_memory_add_by_index(u32 drc_index)696 static int dlpar_memory_add_by_index(u32 drc_index)
697 {
698 	struct drmem_lmb *lmb;
699 	int rc, lmb_found;
700 
701 	pr_info("Attempting to hot-add LMB, drc index %x\n", drc_index);
702 
703 	lmb_found = 0;
704 	for_each_drmem_lmb(lmb) {
705 		if (lmb->drc_index == drc_index) {
706 			lmb_found = 1;
707 			rc = dlpar_acquire_drc(lmb->drc_index);
708 			if (!rc) {
709 				rc = dlpar_add_lmb(lmb);
710 				if (rc)
711 					dlpar_release_drc(lmb->drc_index);
712 			}
713 
714 			break;
715 		}
716 	}
717 
718 	if (!lmb_found)
719 		rc = -EINVAL;
720 
721 	if (rc)
722 		pr_info("Failed to hot-add memory, drc index %x\n", drc_index);
723 	else
724 		pr_info("Memory at %llx (drc index %x) was hot-added\n",
725 			lmb->base_addr, drc_index);
726 
727 	return rc;
728 }
729 
dlpar_memory_add_by_ic(u32 lmbs_to_add,u32 drc_index)730 static int dlpar_memory_add_by_ic(u32 lmbs_to_add, u32 drc_index)
731 {
732 	struct drmem_lmb *lmb, *start_lmb, *end_lmb;
733 	int rc;
734 
735 	pr_info("Attempting to hot-add %u LMB(s) at index %x\n",
736 		lmbs_to_add, drc_index);
737 
738 	if (lmbs_to_add == 0)
739 		return -EINVAL;
740 
741 	rc = get_lmb_range(drc_index, lmbs_to_add, &start_lmb, &end_lmb);
742 	if (rc)
743 		return -EINVAL;
744 
745 	/* Validate that the LMBs in this range are not reserved */
746 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
747 		/* Fail immediately if the whole range can't be hot-added */
748 		if (lmb->flags & DRCONF_MEM_RESERVED) {
749 			pr_err("Memory at %llx (drc index %x) is reserved\n",
750 					lmb->base_addr, lmb->drc_index);
751 			return -EINVAL;
752 		}
753 	}
754 
755 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
756 		if (lmb->flags & DRCONF_MEM_ASSIGNED)
757 			continue;
758 
759 		rc = dlpar_acquire_drc(lmb->drc_index);
760 		if (rc)
761 			break;
762 
763 		rc = dlpar_add_lmb(lmb);
764 		if (rc) {
765 			dlpar_release_drc(lmb->drc_index);
766 			break;
767 		}
768 
769 		drmem_mark_lmb_reserved(lmb);
770 	}
771 
772 	if (rc) {
773 		pr_err("Memory indexed-count-add failed, removing any added LMBs\n");
774 
775 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
776 			if (!drmem_lmb_reserved(lmb))
777 				continue;
778 
779 			rc = dlpar_remove_lmb(lmb);
780 			if (rc)
781 				pr_err("Failed to remove LMB, drc index %x\n",
782 				       lmb->drc_index);
783 			else
784 				dlpar_release_drc(lmb->drc_index);
785 
786 			drmem_remove_lmb_reservation(lmb);
787 		}
788 		rc = -EINVAL;
789 	} else {
790 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
791 			if (!drmem_lmb_reserved(lmb))
792 				continue;
793 
794 			pr_info("Memory at %llx (drc index %x) was hot-added\n",
795 				lmb->base_addr, lmb->drc_index);
796 			drmem_remove_lmb_reservation(lmb);
797 		}
798 	}
799 
800 	return rc;
801 }
802 
dlpar_memory(struct pseries_hp_errorlog * hp_elog)803 int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
804 {
805 	u32 count, drc_index;
806 	int rc;
807 
808 	lock_device_hotplug();
809 
810 	switch (hp_elog->action) {
811 	case PSERIES_HP_ELOG_ACTION_ADD:
812 		switch (hp_elog->id_type) {
813 		case PSERIES_HP_ELOG_ID_DRC_COUNT:
814 			count = be32_to_cpu(hp_elog->_drc_u.drc_count);
815 			rc = dlpar_memory_add_by_count(count);
816 			break;
817 		case PSERIES_HP_ELOG_ID_DRC_INDEX:
818 			drc_index = be32_to_cpu(hp_elog->_drc_u.drc_index);
819 			rc = dlpar_memory_add_by_index(drc_index);
820 			break;
821 		case PSERIES_HP_ELOG_ID_DRC_IC:
822 			count = be32_to_cpu(hp_elog->_drc_u.ic.count);
823 			drc_index = be32_to_cpu(hp_elog->_drc_u.ic.index);
824 			rc = dlpar_memory_add_by_ic(count, drc_index);
825 			break;
826 		default:
827 			rc = -EINVAL;
828 			break;
829 		}
830 
831 		break;
832 	case PSERIES_HP_ELOG_ACTION_REMOVE:
833 		switch (hp_elog->id_type) {
834 		case PSERIES_HP_ELOG_ID_DRC_COUNT:
835 			count = be32_to_cpu(hp_elog->_drc_u.drc_count);
836 			rc = dlpar_memory_remove_by_count(count);
837 			break;
838 		case PSERIES_HP_ELOG_ID_DRC_INDEX:
839 			drc_index = be32_to_cpu(hp_elog->_drc_u.drc_index);
840 			rc = dlpar_memory_remove_by_index(drc_index);
841 			break;
842 		case PSERIES_HP_ELOG_ID_DRC_IC:
843 			count = be32_to_cpu(hp_elog->_drc_u.ic.count);
844 			drc_index = be32_to_cpu(hp_elog->_drc_u.ic.index);
845 			rc = dlpar_memory_remove_by_ic(count, drc_index);
846 			break;
847 		default:
848 			rc = -EINVAL;
849 			break;
850 		}
851 
852 		break;
853 	default:
854 		pr_err("Invalid action (%d) specified\n", hp_elog->action);
855 		rc = -EINVAL;
856 		break;
857 	}
858 
859 	if (!rc)
860 		rc = drmem_update_dt();
861 
862 	unlock_device_hotplug();
863 	return rc;
864 }
865 
pseries_add_mem_node(struct device_node * np)866 static int pseries_add_mem_node(struct device_node *np)
867 {
868 	int ret;
869 	struct resource res;
870 
871 	/*
872 	 * Check to see if we are actually adding memory
873 	 */
874 	if (!of_node_is_type(np, "memory"))
875 		return 0;
876 
877 	/*
878 	 * Find the base and size of the memblock
879 	 */
880 	ret = of_address_to_resource(np, 0, &res);
881 	if (ret)
882 		return ret;
883 
884 	/*
885 	 * Update memory region to represent the memory add
886 	 */
887 	ret = memblock_add(res.start, resource_size(&res));
888 	return (ret < 0) ? -EINVAL : 0;
889 }
890 
pseries_memory_notifier(struct notifier_block * nb,unsigned long action,void * data)891 static int pseries_memory_notifier(struct notifier_block *nb,
892 				   unsigned long action, void *data)
893 {
894 	struct of_reconfig_data *rd = data;
895 	int err = 0;
896 
897 	switch (action) {
898 	case OF_RECONFIG_ATTACH_NODE:
899 		err = pseries_add_mem_node(rd->dn);
900 		break;
901 	case OF_RECONFIG_DETACH_NODE:
902 		err = pseries_remove_mem_node(rd->dn);
903 		break;
904 	case OF_RECONFIG_UPDATE_PROPERTY:
905 		if (!strcmp(rd->dn->name,
906 			    "ibm,dynamic-reconfiguration-memory"))
907 			drmem_update_lmbs(rd->prop);
908 	}
909 	return notifier_from_errno(err);
910 }
911 
912 static struct notifier_block pseries_mem_nb = {
913 	.notifier_call = pseries_memory_notifier,
914 };
915 
pseries_memory_hotplug_init(void)916 static int __init pseries_memory_hotplug_init(void)
917 {
918 	if (firmware_has_feature(FW_FEATURE_LPAR))
919 		of_reconfig_notifier_register(&pseries_mem_nb);
920 
921 	return 0;
922 }
923 machine_device_initcall(pseries, pseries_memory_hotplug_init);
924