xref: /openbmc/linux/arch/powerpc/mm/drmem.c (revision abcda807) 
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 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 
22 u64 drmem_lmb_memory_max(void)
23 {
24 	struct drmem_lmb *last_lmb;
25 
26 	last_lmb = &drmem_info->lmbs[drmem_info->n_lmbs - 1];
27 	return last_lmb->base_addr + drmem_lmb_size();
28 }
29 
30 static u32 drmem_lmb_flags(struct drmem_lmb *lmb)
31 {
32 	/*
33 	 * Return the value of the lmb flags field minus the reserved
34 	 * bit used internally for hotplug processing.
35 	 */
36 	return lmb->flags & ~DRMEM_LMB_RESERVED;
37 }
38 
39 static struct property *clone_property(struct property *prop, u32 prop_sz)
40 {
41 	struct property *new_prop;
42 
43 	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
44 	if (!new_prop)
45 		return NULL;
46 
47 	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
48 	new_prop->value = kzalloc(prop_sz, GFP_KERNEL);
49 	if (!new_prop->name || !new_prop->value) {
50 		kfree(new_prop->name);
51 		kfree(new_prop->value);
52 		kfree(new_prop);
53 		return NULL;
54 	}
55 
56 	new_prop->length = prop_sz;
57 #if defined(CONFIG_OF_DYNAMIC)
58 	of_property_set_flag(new_prop, OF_DYNAMIC);
59 #endif
60 	return new_prop;
61 }
62 
63 static int drmem_update_dt_v1(struct device_node *memory,
64 			      struct property *prop)
65 {
66 	struct property *new_prop;
67 	struct of_drconf_cell_v1 *dr_cell;
68 	struct drmem_lmb *lmb;
69 	u32 *p;
70 
71 	new_prop = clone_property(prop, prop->length);
72 	if (!new_prop)
73 		return -1;
74 
75 	p = new_prop->value;
76 	*p++ = cpu_to_be32(drmem_info->n_lmbs);
77 
78 	dr_cell = (struct of_drconf_cell_v1 *)p;
79 
80 	for_each_drmem_lmb(lmb) {
81 		dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
82 		dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
83 		dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
84 		dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));
85 
86 		dr_cell++;
87 	}
88 
89 	of_update_property(memory, new_prop);
90 	return 0;
91 }
92 
93 static void init_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
94 				struct drmem_lmb *lmb)
95 {
96 	dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
97 	dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
98 	dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
99 	dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));
100 }
101 
102 static int drmem_update_dt_v2(struct device_node *memory,
103 			      struct property *prop)
104 {
105 	struct property *new_prop;
106 	struct of_drconf_cell_v2 *dr_cell;
107 	struct drmem_lmb *lmb, *prev_lmb;
108 	u32 lmb_sets, prop_sz, seq_lmbs;
109 	u32 *p;
110 
111 	/* First pass, determine how many LMB sets are needed. */
112 	lmb_sets = 0;
113 	prev_lmb = NULL;
114 	for_each_drmem_lmb(lmb) {
115 		if (!prev_lmb) {
116 			prev_lmb = lmb;
117 			lmb_sets++;
118 			continue;
119 		}
120 
121 		if (prev_lmb->aa_index != lmb->aa_index ||
122 		    drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb))
123 			lmb_sets++;
124 
125 		prev_lmb = lmb;
126 	}
127 
128 	prop_sz = lmb_sets * sizeof(*dr_cell) + sizeof(__be32);
129 	new_prop = clone_property(prop, prop_sz);
130 	if (!new_prop)
131 		return -1;
132 
133 	p = new_prop->value;
134 	*p++ = cpu_to_be32(lmb_sets);
135 
136 	dr_cell = (struct of_drconf_cell_v2 *)p;
137 
138 	/* Second pass, populate the LMB set data */
139 	prev_lmb = NULL;
140 	seq_lmbs = 0;
141 	for_each_drmem_lmb(lmb) {
142 		if (prev_lmb == NULL) {
143 			/* Start of first LMB set */
144 			prev_lmb = lmb;
145 			init_drconf_v2_cell(dr_cell, lmb);
146 			seq_lmbs++;
147 			continue;
148 		}
149 
150 		if (prev_lmb->aa_index != lmb->aa_index ||
151 		    drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb)) {
152 			/* end of one set, start of another */
153 			dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
154 			dr_cell++;
155 
156 			init_drconf_v2_cell(dr_cell, lmb);
157 			seq_lmbs = 1;
158 		} else {
159 			seq_lmbs++;
160 		}
161 
162 		prev_lmb = lmb;
163 	}
164 
165 	/* close out last LMB set */
166 	dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
167 	of_update_property(memory, new_prop);
168 	return 0;
169 }
170 
171 int drmem_update_dt(void)
172 {
173 	struct device_node *memory;
174 	struct property *prop;
175 	int rc = -1;
176 
177 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
178 	if (!memory)
179 		return -1;
180 
181 	prop = of_find_property(memory, "ibm,dynamic-memory", NULL);
182 	if (prop) {
183 		rc = drmem_update_dt_v1(memory, prop);
184 	} else {
185 		prop = of_find_property(memory, "ibm,dynamic-memory-v2", NULL);
186 		if (prop)
187 			rc = drmem_update_dt_v2(memory, prop);
188 	}
189 
190 	of_node_put(memory);
191 	return rc;
192 }
193 
194 static void read_drconf_v1_cell(struct drmem_lmb *lmb,
195 				       const __be32 **prop)
196 {
197 	const __be32 *p = *prop;
198 
199 	lmb->base_addr = of_read_number(p, n_root_addr_cells);
200 	p += n_root_addr_cells;
201 	lmb->drc_index = of_read_number(p++, 1);
202 
203 	p++; /* skip reserved field */
204 
205 	lmb->aa_index = of_read_number(p++, 1);
206 	lmb->flags = of_read_number(p++, 1);
207 
208 	*prop = p;
209 }
210 
211 static int
212 __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm, void *data,
213 		     int (*func)(struct drmem_lmb *, const __be32 **, void *))
214 {
215 	struct drmem_lmb lmb;
216 	u32 i, n_lmbs;
217 	int ret = 0;
218 
219 	n_lmbs = of_read_number(prop++, 1);
220 	for (i = 0; i < n_lmbs; i++) {
221 		read_drconf_v1_cell(&lmb, &prop);
222 		ret = func(&lmb, &usm, data);
223 		if (ret)
224 			break;
225 	}
226 
227 	return ret;
228 }
229 
230 static void read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
231 				       const __be32 **prop)
232 {
233 	const __be32 *p = *prop;
234 
235 	dr_cell->seq_lmbs = of_read_number(p++, 1);
236 	dr_cell->base_addr = of_read_number(p, n_root_addr_cells);
237 	p += n_root_addr_cells;
238 	dr_cell->drc_index = of_read_number(p++, 1);
239 	dr_cell->aa_index = of_read_number(p++, 1);
240 	dr_cell->flags = of_read_number(p++, 1);
241 
242 	*prop = p;
243 }
244 
245 static int
246 __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm, void *data,
247 		     int (*func)(struct drmem_lmb *, const __be32 **, void *))
248 {
249 	struct of_drconf_cell_v2 dr_cell;
250 	struct drmem_lmb lmb;
251 	u32 i, j, lmb_sets;
252 	int ret = 0;
253 
254 	lmb_sets = of_read_number(prop++, 1);
255 	for (i = 0; i < lmb_sets; i++) {
256 		read_drconf_v2_cell(&dr_cell, &prop);
257 
258 		for (j = 0; j < dr_cell.seq_lmbs; j++) {
259 			lmb.base_addr = dr_cell.base_addr;
260 			dr_cell.base_addr += drmem_lmb_size();
261 
262 			lmb.drc_index = dr_cell.drc_index;
263 			dr_cell.drc_index++;
264 
265 			lmb.aa_index = dr_cell.aa_index;
266 			lmb.flags = dr_cell.flags;
267 
268 			ret = func(&lmb, &usm, data);
269 			if (ret)
270 				break;
271 		}
272 	}
273 
274 	return ret;
275 }
276 
277 #ifdef CONFIG_PPC_PSERIES
278 int __init walk_drmem_lmbs_early(unsigned long node, void *data,
279 		int (*func)(struct drmem_lmb *, const __be32 **, void *))
280 {
281 	const __be32 *prop, *usm;
282 	int len, ret = -ENODEV;
283 
284 	prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
285 	if (!prop || len < dt_root_size_cells * sizeof(__be32))
286 		return ret;
287 
288 	/* Get the address & size cells */
289 	n_root_addr_cells = dt_root_addr_cells;
290 	n_root_size_cells = dt_root_size_cells;
291 
292 	drmem_info->lmb_size = dt_mem_next_cell(dt_root_size_cells, &prop);
293 
294 	usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory", &len);
295 
296 	prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &len);
297 	if (prop) {
298 		ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
299 	} else {
300 		prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory-v2",
301 					   &len);
302 		if (prop)
303 			ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
304 	}
305 
306 	memblock_dump_all();
307 	return ret;
308 }
309 
310 #endif
311 
312 static int init_drmem_lmb_size(struct device_node *dn)
313 {
314 	const __be32 *prop;
315 	int len;
316 
317 	if (drmem_info->lmb_size)
318 		return 0;
319 
320 	prop = of_get_property(dn, "ibm,lmb-size", &len);
321 	if (!prop || len < n_root_size_cells * sizeof(__be32)) {
322 		pr_info("Could not determine LMB size\n");
323 		return -1;
324 	}
325 
326 	drmem_info->lmb_size = of_read_number(prop, n_root_size_cells);
327 	return 0;
328 }
329 
330 /*
331  * Returns the property linux,drconf-usable-memory if
332  * it exists (the property exists only in kexec/kdump kernels,
333  * added by kexec-tools)
334  */
335 static const __be32 *of_get_usable_memory(struct device_node *dn)
336 {
337 	const __be32 *prop;
338 	u32 len;
339 
340 	prop = of_get_property(dn, "linux,drconf-usable-memory", &len);
341 	if (!prop || len < sizeof(unsigned int))
342 		return NULL;
343 
344 	return prop;
345 }
346 
347 int walk_drmem_lmbs(struct device_node *dn, void *data,
348 		    int (*func)(struct drmem_lmb *, const __be32 **, void *))
349 {
350 	const __be32 *prop, *usm;
351 	int ret = -ENODEV;
352 
353 	if (!of_root)
354 		return ret;
355 
356 	/* Get the address & size cells */
357 	of_node_get(of_root);
358 	n_root_addr_cells = of_n_addr_cells(of_root);
359 	n_root_size_cells = of_n_size_cells(of_root);
360 	of_node_put(of_root);
361 
362 	if (init_drmem_lmb_size(dn))
363 		return ret;
364 
365 	usm = of_get_usable_memory(dn);
366 
367 	prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
368 	if (prop) {
369 		ret = __walk_drmem_v1_lmbs(prop, usm, data, func);
370 	} else {
371 		prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
372 		if (prop)
373 			ret = __walk_drmem_v2_lmbs(prop, usm, data, func);
374 	}
375 
376 	return ret;
377 }
378 
379 static void __init init_drmem_v1_lmbs(const __be32 *prop)
380 {
381 	struct drmem_lmb *lmb;
382 
383 	drmem_info->n_lmbs = of_read_number(prop++, 1);
384 	if (drmem_info->n_lmbs == 0)
385 		return;
386 
387 	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
388 				   GFP_KERNEL);
389 	if (!drmem_info->lmbs)
390 		return;
391 
392 	for_each_drmem_lmb(lmb)
393 		read_drconf_v1_cell(lmb, &prop);
394 }
395 
396 static void __init init_drmem_v2_lmbs(const __be32 *prop)
397 {
398 	struct drmem_lmb *lmb;
399 	struct of_drconf_cell_v2 dr_cell;
400 	const __be32 *p;
401 	u32 i, j, lmb_sets;
402 	int lmb_index;
403 
404 	lmb_sets = of_read_number(prop++, 1);
405 	if (lmb_sets == 0)
406 		return;
407 
408 	/* first pass, calculate the number of LMBs */
409 	p = prop;
410 	for (i = 0; i < lmb_sets; i++) {
411 		read_drconf_v2_cell(&dr_cell, &p);
412 		drmem_info->n_lmbs += dr_cell.seq_lmbs;
413 	}
414 
415 	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
416 				   GFP_KERNEL);
417 	if (!drmem_info->lmbs)
418 		return;
419 
420 	/* second pass, read in the LMB information */
421 	lmb_index = 0;
422 	p = prop;
423 
424 	for (i = 0; i < lmb_sets; i++) {
425 		read_drconf_v2_cell(&dr_cell, &p);
426 
427 		for (j = 0; j < dr_cell.seq_lmbs; j++) {
428 			lmb = &drmem_info->lmbs[lmb_index++];
429 
430 			lmb->base_addr = dr_cell.base_addr;
431 			dr_cell.base_addr += drmem_info->lmb_size;
432 
433 			lmb->drc_index = dr_cell.drc_index;
434 			dr_cell.drc_index++;
435 
436 			lmb->aa_index = dr_cell.aa_index;
437 			lmb->flags = dr_cell.flags;
438 		}
439 	}
440 }
441 
442 static int __init drmem_init(void)
443 {
444 	struct device_node *dn;
445 	const __be32 *prop;
446 
447 	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
448 	if (!dn) {
449 		pr_info("No dynamic reconfiguration memory found\n");
450 		return 0;
451 	}
452 
453 	if (init_drmem_lmb_size(dn)) {
454 		of_node_put(dn);
455 		return 0;
456 	}
457 
458 	prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
459 	if (prop) {
460 		init_drmem_v1_lmbs(prop);
461 	} else {
462 		prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
463 		if (prop)
464 			init_drmem_v2_lmbs(prop);
465 	}
466 
467 	of_node_put(dn);
468 	return 0;
469 }
470 late_initcall(drmem_init);
471