xref: /linux/arch/powerpc/mm/drmem.c (revision 5c35a02c545a7bbe77f3a1ae337d9e29beed079b) 
1 /*
2  * Dynamic reconfiguration memory support
3  *
4  * Copyright 2017 IBM Corporation
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #define pr_fmt(fmt) "drmem: " fmt
13 
14 #include <linux/kernel.h>
15 #include <linux/of.h>
16 #include <linux/of_fdt.h>
17 #include <linux/memblock.h>
18 #include <asm/prom.h>
19 #include <asm/drmem.h>
20 
21 static struct drmem_lmb_info __drmem_info;
22 struct drmem_lmb_info *drmem_info = &__drmem_info;
23 
24 u64 drmem_lmb_memory_max(void)
25 {
26 	struct drmem_lmb *last_lmb;
27 
28 	last_lmb = &drmem_info->lmbs[drmem_info->n_lmbs - 1];
29 	return last_lmb->base_addr + drmem_lmb_size();
30 }
31 
32 static u32 drmem_lmb_flags(struct drmem_lmb *lmb)
33 {
34 	/*
35 	 * Return the value of the lmb flags field minus the reserved
36 	 * bit used internally for hotplug processing.
37 	 */
38 	return lmb->flags & ~DRMEM_LMB_RESERVED;
39 }
40 
41 static struct property *clone_property(struct property *prop, u32 prop_sz)
42 {
43 	struct property *new_prop;
44 
45 	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
46 	if (!new_prop)
47 		return NULL;
48 
49 	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
50 	new_prop->value = kzalloc(prop_sz, GFP_KERNEL);
51 	if (!new_prop->name || !new_prop->value) {
52 		kfree(new_prop->name);
53 		kfree(new_prop->value);
54 		kfree(new_prop);
55 		return NULL;
56 	}
57 
58 	new_prop->length = prop_sz;
59 #if defined(CONFIG_OF_DYNAMIC)
60 	of_property_set_flag(new_prop, OF_DYNAMIC);
61 #endif
62 	return new_prop;
63 }
64 
65 static int drmem_update_dt_v1(struct device_node *memory,
66 			      struct property *prop)
67 {
68 	struct property *new_prop;
69 	struct of_drconf_cell_v1 *dr_cell;
70 	struct drmem_lmb *lmb;
71 	u32 *p;
72 
73 	new_prop = clone_property(prop, prop->length);
74 	if (!new_prop)
75 		return -1;
76 
77 	p = new_prop->value;
78 	*p++ = cpu_to_be32(drmem_info->n_lmbs);
79 
80 	dr_cell = (struct of_drconf_cell_v1 *)p;
81 
82 	for_each_drmem_lmb(lmb) {
83 		dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
84 		dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
85 		dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
86 		dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));
87 
88 		dr_cell++;
89 	}
90 
91 	of_update_property(memory, new_prop);
92 	return 0;
93 }
94 
95 static void init_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
96 				struct drmem_lmb *lmb)
97 {
98 	dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
99 	dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
100 	dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
101 	dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));
102 }
103 
104 static int drmem_update_dt_v2(struct device_node *memory,
105 			      struct property *prop)
106 {
107 	struct property *new_prop;
108 	struct of_drconf_cell_v2 *dr_cell;
109 	struct drmem_lmb *lmb, *prev_lmb;
110 	u32 lmb_sets, prop_sz, seq_lmbs;
111 	u32 *p;
112 
113 	/* First pass, determine how many LMB sets are needed. */
114 	lmb_sets = 0;
115 	prev_lmb = NULL;
116 	for_each_drmem_lmb(lmb) {
117 		if (!prev_lmb) {
118 			prev_lmb = lmb;
119 			lmb_sets++;
120 			continue;
121 		}
122 
123 		if (prev_lmb->aa_index != lmb->aa_index ||
124 		    drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb))
125 			lmb_sets++;
126 
127 		prev_lmb = lmb;
128 	}
129 
130 	prop_sz = lmb_sets * sizeof(*dr_cell) + sizeof(__be32);
131 	new_prop = clone_property(prop, prop_sz);
132 	if (!new_prop)
133 		return -1;
134 
135 	p = new_prop->value;
136 	*p++ = cpu_to_be32(lmb_sets);
137 
138 	dr_cell = (struct of_drconf_cell_v2 *)p;
139 
140 	/* Second pass, populate the LMB set data */
141 	prev_lmb = NULL;
142 	seq_lmbs = 0;
143 	for_each_drmem_lmb(lmb) {
144 		if (prev_lmb == NULL) {
145 			/* Start of first LMB set */
146 			prev_lmb = lmb;
147 			init_drconf_v2_cell(dr_cell, lmb);
148 			seq_lmbs++;
149 			continue;
150 		}
151 
152 		if (prev_lmb->aa_index != lmb->aa_index ||
153 		    drmem_lmb_flags(prev_lmb) != drmem_lmb_flags(lmb)) {
154 			/* end of one set, start of another */
155 			dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
156 			dr_cell++;
157 
158 			init_drconf_v2_cell(dr_cell, lmb);
159 			seq_lmbs = 1;
160 		} else {
161 			seq_lmbs++;
162 		}
163 
164 		prev_lmb = lmb;
165 	}
166 
167 	/* close out last LMB set */
168 	dr_cell->seq_lmbs = cpu_to_be32(seq_lmbs);
169 	of_update_property(memory, new_prop);
170 	return 0;
171 }
172 
173 int drmem_update_dt(void)
174 {
175 	struct device_node *memory;
176 	struct property *prop;
177 	int rc = -1;
178 
179 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
180 	if (!memory)
181 		return -1;
182 
183 	prop = of_find_property(memory, "ibm,dynamic-memory", NULL);
184 	if (prop) {
185 		rc = drmem_update_dt_v1(memory, prop);
186 	} else {
187 		prop = of_find_property(memory, "ibm,dynamic-memory-v2", NULL);
188 		if (prop)
189 			rc = drmem_update_dt_v2(memory, prop);
190 	}
191 
192 	of_node_put(memory);
193 	return rc;
194 }
195 
196 static void __init read_drconf_v1_cell(struct drmem_lmb *lmb,
197 				       const __be32 **prop)
198 {
199 	const __be32 *p = *prop;
200 
201 	lmb->base_addr = dt_mem_next_cell(dt_root_addr_cells, &p);
202 	lmb->drc_index = of_read_number(p++, 1);
203 
204 	p++; /* skip reserved field */
205 
206 	lmb->aa_index = of_read_number(p++, 1);
207 	lmb->flags = of_read_number(p++, 1);
208 
209 	*prop = p;
210 }
211 
212 static void __init __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm,
213 			void (*func)(struct drmem_lmb *, const __be32 **))
214 {
215 	struct drmem_lmb lmb;
216 	u32 i, n_lmbs;
217 
218 	n_lmbs = of_read_number(prop++, 1);
219 	if (n_lmbs == 0)
220 		return;
221 
222 	for (i = 0; i < n_lmbs; i++) {
223 		read_drconf_v1_cell(&lmb, &prop);
224 		func(&lmb, &usm);
225 	}
226 }
227 
228 static void __init read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
229 				       const __be32 **prop)
230 {
231 	const __be32 *p = *prop;
232 
233 	dr_cell->seq_lmbs = of_read_number(p++, 1);
234 	dr_cell->base_addr = dt_mem_next_cell(dt_root_addr_cells, &p);
235 	dr_cell->drc_index = of_read_number(p++, 1);
236 	dr_cell->aa_index = of_read_number(p++, 1);
237 	dr_cell->flags = of_read_number(p++, 1);
238 
239 	*prop = p;
240 }
241 
242 static void __init __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm,
243 			void (*func)(struct drmem_lmb *, const __be32 **))
244 {
245 	struct of_drconf_cell_v2 dr_cell;
246 	struct drmem_lmb lmb;
247 	u32 i, j, lmb_sets;
248 
249 	lmb_sets = of_read_number(prop++, 1);
250 	if (lmb_sets == 0)
251 		return;
252 
253 	for (i = 0; i < lmb_sets; i++) {
254 		read_drconf_v2_cell(&dr_cell, &prop);
255 
256 		for (j = 0; j < dr_cell.seq_lmbs; j++) {
257 			lmb.base_addr = dr_cell.base_addr;
258 			dr_cell.base_addr += drmem_lmb_size();
259 
260 			lmb.drc_index = dr_cell.drc_index;
261 			dr_cell.drc_index++;
262 
263 			lmb.aa_index = dr_cell.aa_index;
264 			lmb.flags = dr_cell.flags;
265 
266 			func(&lmb, &usm);
267 		}
268 	}
269 }
270 
271 #ifdef CONFIG_PPC_PSERIES
272 void __init walk_drmem_lmbs_early(unsigned long node,
273 			void (*func)(struct drmem_lmb *, const __be32 **))
274 {
275 	const __be32 *prop, *usm;
276 	int len;
277 
278 	prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
279 	if (!prop || len < dt_root_size_cells * sizeof(__be32))
280 		return;
281 
282 	drmem_info->lmb_size = dt_mem_next_cell(dt_root_size_cells, &prop);
283 
284 	usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory", &len);
285 
286 	prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &len);
287 	if (prop) {
288 		__walk_drmem_v1_lmbs(prop, usm, func);
289 	} else {
290 		prop = of_get_flat_dt_prop(node, "ibm,dynamic-memory-v2",
291 					   &len);
292 		if (prop)
293 			__walk_drmem_v2_lmbs(prop, usm, func);
294 	}
295 
296 	memblock_dump_all();
297 }
298 
299 #endif
300 
301 static int __init init_drmem_lmb_size(struct device_node *dn)
302 {
303 	const __be32 *prop;
304 	int len;
305 
306 	if (drmem_info->lmb_size)
307 		return 0;
308 
309 	prop = of_get_property(dn, "ibm,lmb-size", &len);
310 	if (!prop || len < dt_root_size_cells * sizeof(__be32)) {
311 		pr_info("Could not determine LMB size\n");
312 		return -1;
313 	}
314 
315 	drmem_info->lmb_size = dt_mem_next_cell(dt_root_size_cells, &prop);
316 	return 0;
317 }
318 
319 /*
320  * Returns the property linux,drconf-usable-memory if
321  * it exists (the property exists only in kexec/kdump kernels,
322  * added by kexec-tools)
323  */
324 static const __be32 *of_get_usable_memory(struct device_node *dn)
325 {
326 	const __be32 *prop;
327 	u32 len;
328 
329 	prop = of_get_property(dn, "linux,drconf-usable-memory", &len);
330 	if (!prop || len < sizeof(unsigned int))
331 		return NULL;
332 
333 	return prop;
334 }
335 
336 void __init walk_drmem_lmbs(struct device_node *dn,
337 			    void (*func)(struct drmem_lmb *, const __be32 **))
338 {
339 	const __be32 *prop, *usm;
340 
341 	if (init_drmem_lmb_size(dn))
342 		return;
343 
344 	usm = of_get_usable_memory(dn);
345 
346 	prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
347 	if (prop) {
348 		__walk_drmem_v1_lmbs(prop, usm, func);
349 	} else {
350 		prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
351 		if (prop)
352 			__walk_drmem_v2_lmbs(prop, usm, func);
353 	}
354 }
355 
356 static void __init init_drmem_v1_lmbs(const __be32 *prop)
357 {
358 	struct drmem_lmb *lmb;
359 
360 	drmem_info->n_lmbs = of_read_number(prop++, 1);
361 	if (drmem_info->n_lmbs == 0)
362 		return;
363 
364 	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
365 				   GFP_KERNEL);
366 	if (!drmem_info->lmbs)
367 		return;
368 
369 	for_each_drmem_lmb(lmb)
370 		read_drconf_v1_cell(lmb, &prop);
371 }
372 
373 static void __init init_drmem_v2_lmbs(const __be32 *prop)
374 {
375 	struct drmem_lmb *lmb;
376 	struct of_drconf_cell_v2 dr_cell;
377 	const __be32 *p;
378 	u32 i, j, lmb_sets;
379 	int lmb_index;
380 
381 	lmb_sets = of_read_number(prop++, 1);
382 	if (lmb_sets == 0)
383 		return;
384 
385 	/* first pass, calculate the number of LMBs */
386 	p = prop;
387 	for (i = 0; i < lmb_sets; i++) {
388 		read_drconf_v2_cell(&dr_cell, &p);
389 		drmem_info->n_lmbs += dr_cell.seq_lmbs;
390 	}
391 
392 	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
393 				   GFP_KERNEL);
394 	if (!drmem_info->lmbs)
395 		return;
396 
397 	/* second pass, read in the LMB information */
398 	lmb_index = 0;
399 	p = prop;
400 
401 	for (i = 0; i < lmb_sets; i++) {
402 		read_drconf_v2_cell(&dr_cell, &p);
403 
404 		for (j = 0; j < dr_cell.seq_lmbs; j++) {
405 			lmb = &drmem_info->lmbs[lmb_index++];
406 
407 			lmb->base_addr = dr_cell.base_addr;
408 			dr_cell.base_addr += drmem_info->lmb_size;
409 
410 			lmb->drc_index = dr_cell.drc_index;
411 			dr_cell.drc_index++;
412 
413 			lmb->aa_index = dr_cell.aa_index;
414 			lmb->flags = dr_cell.flags;
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