xref: /linux/arch/powerpc/mm/drmem.c (revision 63307d015b91e626c97bb82e88054af3d0b74643) 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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
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 
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  */
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 
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 
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 
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 
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