Merge tag 'powerpc-5.0-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...
[muen/linux.git] / arch / powerpc / platforms / pseries / papr_scm.c
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
15 #include <asm/plpar_wrappers.h>
16
17 #define BIND_ANY_ADDR (~0ul)
18
19 #define PAPR_SCM_DIMM_CMD_MASK \
20         ((1ul << ND_CMD_GET_CONFIG_SIZE) | \
21          (1ul << ND_CMD_GET_CONFIG_DATA) | \
22          (1ul << ND_CMD_SET_CONFIG_DATA))
23
24 struct papr_scm_priv {
25         struct platform_device *pdev;
26         struct device_node *dn;
27         uint32_t drc_index;
28         uint64_t blocks;
29         uint64_t block_size;
30         int metadata_size;
31
32         uint64_t bound_addr;
33
34         struct nvdimm_bus_descriptor bus_desc;
35         struct nvdimm_bus *bus;
36         struct nvdimm *nvdimm;
37         struct resource res;
38         struct nd_region *region;
39         struct nd_interleave_set nd_set;
40 };
41
42 static int drc_pmem_bind(struct papr_scm_priv *p)
43 {
44         unsigned long ret[PLPAR_HCALL_BUFSIZE];
45         uint64_t rc, token;
46         uint64_t saved = 0;
47
48         /*
49          * When the hypervisor cannot map all the requested memory in a single
50          * hcall it returns H_BUSY and we call again with the token until
51          * we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
52          * leave the system in an undefined state, so we wait.
53          */
54         token = 0;
55
56         do {
57                 rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
58                                 p->blocks, BIND_ANY_ADDR, token);
59                 token = ret[0];
60                 if (!saved)
61                         saved = ret[1];
62                 cond_resched();
63         } while (rc == H_BUSY);
64
65         if (rc) {
66                 dev_err(&p->pdev->dev, "bind err: %lld\n", rc);
67                 return -ENXIO;
68         }
69
70         p->bound_addr = saved;
71
72         dev_dbg(&p->pdev->dev, "bound drc %x to %pR\n", p->drc_index, &p->res);
73
74         return 0;
75 }
76
77 static int drc_pmem_unbind(struct papr_scm_priv *p)
78 {
79         unsigned long ret[PLPAR_HCALL_BUFSIZE];
80         uint64_t rc, token;
81
82         token = 0;
83
84         /* NB: unbind has the same retry requirements mentioned above */
85         do {
86                 rc = plpar_hcall(H_SCM_UNBIND_MEM, ret, p->drc_index,
87                                 p->bound_addr, p->blocks, token);
88                 token = ret[0];
89                 cond_resched();
90         } while (rc == H_BUSY);
91
92         if (rc)
93                 dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
94
95         return !!rc;
96 }
97
98 static int papr_scm_meta_get(struct papr_scm_priv *p,
99                         struct nd_cmd_get_config_data_hdr *hdr)
100 {
101         unsigned long data[PLPAR_HCALL_BUFSIZE];
102         int64_t ret;
103
104         if (hdr->in_offset >= p->metadata_size || hdr->in_length != 1)
105                 return -EINVAL;
106
107         ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
108                         hdr->in_offset, 1);
109
110         if (ret == H_PARAMETER) /* bad DRC index */
111                 return -ENODEV;
112         if (ret)
113                 return -EINVAL; /* other invalid parameter */
114
115         hdr->out_buf[0] = data[0] & 0xff;
116
117         return 0;
118 }
119
120 static int papr_scm_meta_set(struct papr_scm_priv *p,
121                         struct nd_cmd_set_config_hdr *hdr)
122 {
123         int64_t ret;
124
125         if (hdr->in_offset >= p->metadata_size || hdr->in_length != 1)
126                 return -EINVAL;
127
128         ret = plpar_hcall_norets(H_SCM_WRITE_METADATA,
129                         p->drc_index, hdr->in_offset, hdr->in_buf[0], 1);
130
131         if (ret == H_PARAMETER) /* bad DRC index */
132                 return -ENODEV;
133         if (ret)
134                 return -EINVAL; /* other invalid parameter */
135
136         return 0;
137 }
138
139 int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
140                 unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
141 {
142         struct nd_cmd_get_config_size *get_size_hdr;
143         struct papr_scm_priv *p;
144
145         /* Only dimm-specific calls are supported atm */
146         if (!nvdimm)
147                 return -EINVAL;
148
149         p = nvdimm_provider_data(nvdimm);
150
151         switch (cmd) {
152         case ND_CMD_GET_CONFIG_SIZE:
153                 get_size_hdr = buf;
154
155                 get_size_hdr->status = 0;
156                 get_size_hdr->max_xfer = 1;
157                 get_size_hdr->config_size = p->metadata_size;
158                 *cmd_rc = 0;
159                 break;
160
161         case ND_CMD_GET_CONFIG_DATA:
162                 *cmd_rc = papr_scm_meta_get(p, buf);
163                 break;
164
165         case ND_CMD_SET_CONFIG_DATA:
166                 *cmd_rc = papr_scm_meta_set(p, buf);
167                 break;
168
169         default:
170                 return -EINVAL;
171         }
172
173         dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
174
175         return 0;
176 }
177
178 static const struct attribute_group *region_attr_groups[] = {
179         &nd_region_attribute_group,
180         &nd_device_attribute_group,
181         &nd_mapping_attribute_group,
182         &nd_numa_attribute_group,
183         NULL,
184 };
185
186 static const struct attribute_group *bus_attr_groups[] = {
187         &nvdimm_bus_attribute_group,
188         NULL,
189 };
190
191 static const struct attribute_group *papr_scm_dimm_groups[] = {
192         &nvdimm_attribute_group,
193         &nd_device_attribute_group,
194         NULL,
195 };
196
197 static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
198 {
199         struct device *dev = &p->pdev->dev;
200         struct nd_mapping_desc mapping;
201         struct nd_region_desc ndr_desc;
202         unsigned long dimm_flags;
203
204         p->bus_desc.ndctl = papr_scm_ndctl;
205         p->bus_desc.module = THIS_MODULE;
206         p->bus_desc.of_node = p->pdev->dev.of_node;
207         p->bus_desc.attr_groups = bus_attr_groups;
208         p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);
209
210         if (!p->bus_desc.provider_name)
211                 return -ENOMEM;
212
213         p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
214         if (!p->bus) {
215                 dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
216                 return -ENXIO;
217         }
218
219         dimm_flags = 0;
220         set_bit(NDD_ALIASING, &dimm_flags);
221
222         p->nvdimm = nvdimm_create(p->bus, p, papr_scm_dimm_groups,
223                                 dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
224         if (!p->nvdimm) {
225                 dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
226                 goto err;
227         }
228
229         if (nvdimm_bus_check_dimm_count(p->bus, 1))
230                 goto err;
231
232         /* now add the region */
233
234         memset(&mapping, 0, sizeof(mapping));
235         mapping.nvdimm = p->nvdimm;
236         mapping.start = 0;
237         mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
238
239         memset(&ndr_desc, 0, sizeof(ndr_desc));
240         ndr_desc.attr_groups = region_attr_groups;
241         ndr_desc.numa_node = dev_to_node(&p->pdev->dev);
242         ndr_desc.res = &p->res;
243         ndr_desc.of_node = p->dn;
244         ndr_desc.provider_data = p;
245         ndr_desc.mapping = &mapping;
246         ndr_desc.num_mappings = 1;
247         ndr_desc.nd_set = &p->nd_set;
248         set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
249
250         p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
251         if (!p->region) {
252                 dev_err(dev, "Error registering region %pR from %pOF\n",
253                                 ndr_desc.res, p->dn);
254                 goto err;
255         }
256
257         return 0;
258
259 err:    nvdimm_bus_unregister(p->bus);
260         kfree(p->bus_desc.provider_name);
261         return -ENXIO;
262 }
263
264 static int papr_scm_probe(struct platform_device *pdev)
265 {
266         struct device_node *dn = pdev->dev.of_node;
267         u32 drc_index, metadata_size;
268         u64 blocks, block_size;
269         struct papr_scm_priv *p;
270         const char *uuid_str;
271         u64 uuid[2];
272         int rc;
273
274         /* check we have all the required DT properties */
275         if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
276                 dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
277                 return -ENODEV;
278         }
279
280         if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
281                 dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
282                 return -ENODEV;
283         }
284
285         if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
286                 dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
287                 return -ENODEV;
288         }
289
290         if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
291                 dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
292                 return -ENODEV;
293         }
294
295         p = kzalloc(sizeof(*p), GFP_KERNEL);
296         if (!p)
297                 return -ENOMEM;
298
299         /* optional DT properties */
300         of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
301
302         p->dn = dn;
303         p->drc_index = drc_index;
304         p->block_size = block_size;
305         p->blocks = blocks;
306
307         /* We just need to ensure that set cookies are unique across */
308         uuid_parse(uuid_str, (uuid_t *) uuid);
309         p->nd_set.cookie1 = uuid[0];
310         p->nd_set.cookie2 = uuid[1];
311
312         /* might be zero */
313         p->metadata_size = metadata_size;
314         p->pdev = pdev;
315
316         /* request the hypervisor to bind this region to somewhere in memory */
317         rc = drc_pmem_bind(p);
318         if (rc)
319                 goto err;
320
321         /* setup the resource for the newly bound range */
322         p->res.start = p->bound_addr;
323         p->res.end   = p->bound_addr + p->blocks * p->block_size - 1;
324         p->res.name  = pdev->name;
325         p->res.flags = IORESOURCE_MEM;
326
327         rc = papr_scm_nvdimm_init(p);
328         if (rc)
329                 goto err2;
330
331         platform_set_drvdata(pdev, p);
332
333         return 0;
334
335 err2:   drc_pmem_unbind(p);
336 err:    kfree(p);
337         return rc;
338 }
339
340 static int papr_scm_remove(struct platform_device *pdev)
341 {
342         struct papr_scm_priv *p = platform_get_drvdata(pdev);
343
344         nvdimm_bus_unregister(p->bus);
345         drc_pmem_unbind(p);
346         kfree(p);
347
348         return 0;
349 }
350
351 static const struct of_device_id papr_scm_match[] = {
352         { .compatible = "ibm,pmemory" },
353         { },
354 };
355
356 static struct platform_driver papr_scm_driver = {
357         .probe = papr_scm_probe,
358         .remove = papr_scm_remove,
359         .driver = {
360                 .name = "papr_scm",
361                 .owner = THIS_MODULE,
362                 .of_match_table = papr_scm_match,
363         },
364 };
365
366 module_platform_driver(papr_scm_driver);
367 MODULE_DEVICE_TABLE(of, papr_scm_match);
368 MODULE_LICENSE("GPL");
369 MODULE_AUTHOR("IBM Corporation");