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