1 // SPDX-License-Identifier: GPL-2.0
2
3 #define pr_fmt(fmt) "papr-scm: " fmt
4
5 #include <linux/of.h>
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/ioport.h>
9 #include <linux/slab.h>
10 #include <linux/ndctl.h>
11 #include <linux/sched.h>
12 #include <linux/libnvdimm.h>
13 #include <linux/platform_device.h>
14 #include <linux/delay.h>
15
16 #include <asm/plpar_wrappers.h>
17
18 #define BIND_ANY_ADDR (~0ul)
19
20 #define PAPR_SCM_DIMM_CMD_MASK \
21 ((1ul << ND_CMD_GET_CONFIG_SIZE) | \
22 (1ul << ND_CMD_GET_CONFIG_DATA) | \
23 (1ul << ND_CMD_SET_CONFIG_DATA))
24
25 struct papr_scm_priv {
26 struct platform_device *pdev;
27 struct device_node *dn;
28 uint32_t drc_index;
29 uint64_t blocks;
30 uint64_t block_size;
31 int metadata_size;
32 bool is_volatile;
33
34 uint64_t bound_addr;
35
36 struct nvdimm_bus_descriptor bus_desc;
37 struct nvdimm_bus *bus;
38 struct nvdimm *nvdimm;
39 struct resource res;
40 struct nd_region *region;
41 struct nd_interleave_set nd_set;
42 };
43
drc_pmem_bind(struct papr_scm_priv * p)44 static int drc_pmem_bind(struct papr_scm_priv *p)
45 {
46 unsigned long ret[PLPAR_HCALL_BUFSIZE];
47 uint64_t saved = 0;
48 uint64_t token;
49 int64_t rc;
50
51 /*
52 * When the hypervisor cannot map all the requested memory in a single
53 * hcall it returns H_BUSY and we call again with the token until
54 * we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
55 * leave the system in an undefined state, so we wait.
56 */
57 token = 0;
58
59 do {
60 rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
61 p->blocks, BIND_ANY_ADDR, token);
62 token = ret[0];
63 if (!saved)
64 saved = ret[1];
65 cond_resched();
66 } while (rc == H_BUSY);
67
68 if (rc)
69 return rc;
70
71 p->bound_addr = saved;
72 dev_dbg(&p->pdev->dev, "bound drc 0x%x to %pR\n", p->drc_index, &p->res);
73 return rc;
74 }
75
drc_pmem_unbind(struct papr_scm_priv * p)76 static void drc_pmem_unbind(struct papr_scm_priv *p)
77 {
78 unsigned long ret[PLPAR_HCALL_BUFSIZE];
79 uint64_t token = 0;
80 int64_t rc;
81
82 dev_dbg(&p->pdev->dev, "unbind drc 0x%x\n", p->drc_index);
83
84 /* NB: unbind has the same retry requirements as drc_pmem_bind() */
85 do {
86
87 /* Unbind of all SCM resources associated with drcIndex */
88 rc = plpar_hcall(H_SCM_UNBIND_ALL, ret, H_UNBIND_SCOPE_DRC,
89 p->drc_index, token);
90 token = ret[0];
91
92 /* Check if we are stalled for some time */
93 if (H_IS_LONG_BUSY(rc)) {
94 msleep(get_longbusy_msecs(rc));
95 rc = H_BUSY;
96 } else if (rc == H_BUSY) {
97 cond_resched();
98 }
99
100 } while (rc == H_BUSY);
101
102 if (rc)
103 dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
104 else
105 dev_dbg(&p->pdev->dev, "unbind drc 0x%x complete\n",
106 p->drc_index);
107
108 return;
109 }
110
drc_pmem_query_n_bind(struct papr_scm_priv * p)111 static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
112 {
113 unsigned long start_addr;
114 unsigned long end_addr;
115 unsigned long ret[PLPAR_HCALL_BUFSIZE];
116 int64_t rc;
117
118
119 rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
120 p->drc_index, 0);
121 if (rc)
122 goto err_out;
123 start_addr = ret[0];
124
125 /* Make sure the full region is bound. */
126 rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
127 p->drc_index, p->blocks - 1);
128 if (rc)
129 goto err_out;
130 end_addr = ret[0];
131
132 if ((end_addr - start_addr) != ((p->blocks - 1) * p->block_size))
133 goto err_out;
134
135 p->bound_addr = start_addr;
136 dev_dbg(&p->pdev->dev, "bound drc 0x%x to %pR\n", p->drc_index, &p->res);
137 return rc;
138
139 err_out:
140 dev_info(&p->pdev->dev,
141 "Failed to query, trying an unbind followed by bind");
142 drc_pmem_unbind(p);
143 return drc_pmem_bind(p);
144 }
145
146
papr_scm_meta_get(struct papr_scm_priv * p,struct nd_cmd_get_config_data_hdr * hdr)147 static int papr_scm_meta_get(struct papr_scm_priv *p,
148 struct nd_cmd_get_config_data_hdr *hdr)
149 {
150 unsigned long data[PLPAR_HCALL_BUFSIZE];
151 unsigned long offset, data_offset;
152 int len, read;
153 int64_t ret;
154
155 if ((hdr->in_offset + hdr->in_length) >= p->metadata_size)
156 return -EINVAL;
157
158 for (len = hdr->in_length; len; len -= read) {
159
160 data_offset = hdr->in_length - len;
161 offset = hdr->in_offset + data_offset;
162
163 if (len >= 8)
164 read = 8;
165 else if (len >= 4)
166 read = 4;
167 else if (len >= 2)
168 read = 2;
169 else
170 read = 1;
171
172 ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
173 offset, read);
174
175 if (ret == H_PARAMETER) /* bad DRC index */
176 return -ENODEV;
177 if (ret)
178 return -EINVAL; /* other invalid parameter */
179
180 switch (read) {
181 case 8:
182 *(uint64_t *)(hdr->out_buf + data_offset) = be64_to_cpu(data[0]);
183 break;
184 case 4:
185 *(uint32_t *)(hdr->out_buf + data_offset) = be32_to_cpu(data[0] & 0xffffffff);
186 break;
187
188 case 2:
189 *(uint16_t *)(hdr->out_buf + data_offset) = be16_to_cpu(data[0] & 0xffff);
190 break;
191
192 case 1:
193 *(uint8_t *)(hdr->out_buf + data_offset) = (data[0] & 0xff);
194 break;
195 }
196 }
197 return 0;
198 }
199
papr_scm_meta_set(struct papr_scm_priv * p,struct nd_cmd_set_config_hdr * hdr)200 static int papr_scm_meta_set(struct papr_scm_priv *p,
201 struct nd_cmd_set_config_hdr *hdr)
202 {
203 unsigned long offset, data_offset;
204 int len, wrote;
205 unsigned long data;
206 __be64 data_be;
207 int64_t ret;
208
209 if ((hdr->in_offset + hdr->in_length) >= p->metadata_size)
210 return -EINVAL;
211
212 for (len = hdr->in_length; len; len -= wrote) {
213
214 data_offset = hdr->in_length - len;
215 offset = hdr->in_offset + data_offset;
216
217 if (len >= 8) {
218 data = *(uint64_t *)(hdr->in_buf + data_offset);
219 data_be = cpu_to_be64(data);
220 wrote = 8;
221 } else if (len >= 4) {
222 data = *(uint32_t *)(hdr->in_buf + data_offset);
223 data &= 0xffffffff;
224 data_be = cpu_to_be32(data);
225 wrote = 4;
226 } else if (len >= 2) {
227 data = *(uint16_t *)(hdr->in_buf + data_offset);
228 data &= 0xffff;
229 data_be = cpu_to_be16(data);
230 wrote = 2;
231 } else {
232 data_be = *(uint8_t *)(hdr->in_buf + data_offset);
233 data_be &= 0xff;
234 wrote = 1;
235 }
236
237 ret = plpar_hcall_norets(H_SCM_WRITE_METADATA, p->drc_index,
238 offset, data_be, wrote);
239 if (ret == H_PARAMETER) /* bad DRC index */
240 return -ENODEV;
241 if (ret)
242 return -EINVAL; /* other invalid parameter */
243 }
244
245 return 0;
246 }
247
papr_scm_ndctl(struct nvdimm_bus_descriptor * nd_desc,struct nvdimm * nvdimm,unsigned int cmd,void * buf,unsigned int buf_len,int * cmd_rc)248 int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
249 unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
250 {
251 struct nd_cmd_get_config_size *get_size_hdr;
252 struct papr_scm_priv *p;
253
254 /* Only dimm-specific calls are supported atm */
255 if (!nvdimm)
256 return -EINVAL;
257
258 p = nvdimm_provider_data(nvdimm);
259
260 switch (cmd) {
261 case ND_CMD_GET_CONFIG_SIZE:
262 get_size_hdr = buf;
263
264 get_size_hdr->status = 0;
265 get_size_hdr->max_xfer = 8;
266 get_size_hdr->config_size = p->metadata_size;
267 *cmd_rc = 0;
268 break;
269
270 case ND_CMD_GET_CONFIG_DATA:
271 *cmd_rc = papr_scm_meta_get(p, buf);
272 break;
273
274 case ND_CMD_SET_CONFIG_DATA:
275 *cmd_rc = papr_scm_meta_set(p, buf);
276 break;
277
278 default:
279 return -EINVAL;
280 }
281
282 dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
283
284 return 0;
285 }
286
287 static const struct attribute_group *region_attr_groups[] = {
288 &nd_region_attribute_group,
289 &nd_device_attribute_group,
290 &nd_mapping_attribute_group,
291 &nd_numa_attribute_group,
292 NULL,
293 };
294
295 static const struct attribute_group *bus_attr_groups[] = {
296 &nvdimm_bus_attribute_group,
297 NULL,
298 };
299
300 static const struct attribute_group *papr_scm_dimm_groups[] = {
301 &nvdimm_attribute_group,
302 &nd_device_attribute_group,
303 NULL,
304 };
305
papr_scm_node(int node)306 static inline int papr_scm_node(int node)
307 {
308 int min_dist = INT_MAX, dist;
309 int nid, min_node;
310
311 if ((node == NUMA_NO_NODE) || node_online(node))
312 return node;
313
314 min_node = first_online_node;
315 for_each_online_node(nid) {
316 dist = node_distance(node, nid);
317 if (dist < min_dist) {
318 min_dist = dist;
319 min_node = nid;
320 }
321 }
322 return min_node;
323 }
324
papr_scm_nvdimm_init(struct papr_scm_priv * p)325 static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
326 {
327 struct device *dev = &p->pdev->dev;
328 struct nd_mapping_desc mapping;
329 struct nd_region_desc ndr_desc;
330 unsigned long dimm_flags;
331 int target_nid, online_nid;
332
333 p->bus_desc.ndctl = papr_scm_ndctl;
334 p->bus_desc.module = THIS_MODULE;
335 p->bus_desc.of_node = p->pdev->dev.of_node;
336 p->bus_desc.attr_groups = bus_attr_groups;
337 p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);
338
339 if (!p->bus_desc.provider_name)
340 return -ENOMEM;
341
342 p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
343 if (!p->bus) {
344 dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
345 return -ENXIO;
346 }
347
348 dimm_flags = 0;
349 set_bit(NDD_ALIASING, &dimm_flags);
350
351 p->nvdimm = nvdimm_create(p->bus, p, papr_scm_dimm_groups,
352 dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
353 if (!p->nvdimm) {
354 dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
355 goto err;
356 }
357
358 if (nvdimm_bus_check_dimm_count(p->bus, 1))
359 goto err;
360
361 /* now add the region */
362
363 memset(&mapping, 0, sizeof(mapping));
364 mapping.nvdimm = p->nvdimm;
365 mapping.start = 0;
366 mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
367
368 memset(&ndr_desc, 0, sizeof(ndr_desc));
369 ndr_desc.attr_groups = region_attr_groups;
370 target_nid = dev_to_node(&p->pdev->dev);
371 online_nid = papr_scm_node(target_nid);
372 ndr_desc.numa_node = online_nid;
373 ndr_desc.target_node = target_nid;
374 ndr_desc.res = &p->res;
375 ndr_desc.of_node = p->dn;
376 ndr_desc.provider_data = p;
377 ndr_desc.mapping = &mapping;
378 ndr_desc.num_mappings = 1;
379 ndr_desc.nd_set = &p->nd_set;
380 set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
381
382 if (p->is_volatile)
383 p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc);
384 else
385 p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
386 if (!p->region) {
387 dev_err(dev, "Error registering region %pR from %pOF\n",
388 ndr_desc.res, p->dn);
389 goto err;
390 }
391 if (target_nid != online_nid)
392 dev_info(dev, "Region registered with target node %d and online node %d",
393 target_nid, online_nid);
394
395 return 0;
396
397 err: nvdimm_bus_unregister(p->bus);
398 kfree(p->bus_desc.provider_name);
399 return -ENXIO;
400 }
401
papr_scm_probe(struct platform_device * pdev)402 static int papr_scm_probe(struct platform_device *pdev)
403 {
404 struct device_node *dn = pdev->dev.of_node;
405 u32 drc_index, metadata_size;
406 u64 blocks, block_size;
407 struct papr_scm_priv *p;
408 const char *uuid_str;
409 u64 uuid[2];
410 int rc;
411
412 /* check we have all the required DT properties */
413 if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
414 dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
415 return -ENODEV;
416 }
417
418 if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
419 dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
420 return -ENODEV;
421 }
422
423 if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
424 dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
425 return -ENODEV;
426 }
427
428 if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
429 dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
430 return -ENODEV;
431 }
432
433
434 p = kzalloc(sizeof(*p), GFP_KERNEL);
435 if (!p)
436 return -ENOMEM;
437
438 /* optional DT properties */
439 of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
440
441 p->dn = dn;
442 p->drc_index = drc_index;
443 p->block_size = block_size;
444 p->blocks = blocks;
445 p->is_volatile = !of_property_read_bool(dn, "ibm,cache-flush-required");
446
447 /* We just need to ensure that set cookies are unique across */
448 uuid_parse(uuid_str, (uuid_t *) uuid);
449 /*
450 * cookie1 and cookie2 are not really little endian
451 * we store a little endian representation of the
452 * uuid str so that we can compare this with the label
453 * area cookie irrespective of the endian config with which
454 * the kernel is built.
455 */
456 p->nd_set.cookie1 = cpu_to_le64(uuid[0]);
457 p->nd_set.cookie2 = cpu_to_le64(uuid[1]);
458
459 /* might be zero */
460 p->metadata_size = metadata_size;
461 p->pdev = pdev;
462
463 /* request the hypervisor to bind this region to somewhere in memory */
464 rc = drc_pmem_bind(p);
465
466 /* If phyp says drc memory still bound then force unbound and retry */
467 if (rc == H_OVERLAP)
468 rc = drc_pmem_query_n_bind(p);
469
470 if (rc != H_SUCCESS) {
471 dev_err(&p->pdev->dev, "bind err: %d\n", rc);
472 rc = -ENXIO;
473 goto err;
474 }
475
476 /* setup the resource for the newly bound range */
477 p->res.start = p->bound_addr;
478 p->res.end = p->bound_addr + p->blocks * p->block_size - 1;
479 p->res.name = pdev->name;
480 p->res.flags = IORESOURCE_MEM;
481
482 rc = papr_scm_nvdimm_init(p);
483 if (rc)
484 goto err2;
485
486 platform_set_drvdata(pdev, p);
487
488 return 0;
489
490 err2: drc_pmem_unbind(p);
491 err: kfree(p);
492 return rc;
493 }
494
papr_scm_remove(struct platform_device * pdev)495 static int papr_scm_remove(struct platform_device *pdev)
496 {
497 struct papr_scm_priv *p = platform_get_drvdata(pdev);
498
499 nvdimm_bus_unregister(p->bus);
500 drc_pmem_unbind(p);
501 kfree(p);
502
503 return 0;
504 }
505
506 static const struct of_device_id papr_scm_match[] = {
507 { .compatible = "ibm,pmemory" },
508 { },
509 };
510
511 static struct platform_driver papr_scm_driver = {
512 .probe = papr_scm_probe,
513 .remove = papr_scm_remove,
514 .driver = {
515 .name = "papr_scm",
516 .owner = THIS_MODULE,
517 .of_match_table = papr_scm_match,
518 },
519 };
520
521 module_platform_driver(papr_scm_driver);
522 MODULE_DEVICE_TABLE(of, papr_scm_match);
523 MODULE_LICENSE("GPL");
524 MODULE_AUTHOR("IBM Corporation");
525
