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         bool is_volatile;
  32
  33         uint64_t bound_addr;
  34
  35         struct nvdimm_bus_descriptor bus_desc;
  36         struct nvdimm_bus *bus;
  37         struct nvdimm *nvdimm;
  38         struct resource res;
  39         struct nd_region *region;
  40         struct nd_interleave_set nd_set;
  41 };
  42
  43 static int drc_pmem_bind(struct papr_scm_priv *p)
  44 {
  45         unsigned long ret[PLPAR_HCALL_BUFSIZE];
  46         uint64_t rc, token;
  47         uint64_t saved = 0;
  48
  49         /*
  50          * When the hypervisor cannot map all the requested memory in a single
  51          * hcall it returns H_BUSY and we call again with the token until
  52          * we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
  53          * leave the system in an undefined state, so we wait.
  54          */
  55         token = 0;
  56
  57         do {
  58                 rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
  59                                 p->blocks, BIND_ANY_ADDR, token);
  60                 token = ret[0];
  61                 if (!saved)
  62                         saved = ret[1];
  63                 cond_resched();
  64         } while (rc == H_BUSY);
  65
  66         if (rc) {
  67                 dev_err(&p->pdev->dev, "bind err: %lld\n", rc);
  68                 return -ENXIO;
  69         }
  70
  71         p->bound_addr = saved;
  72
  73         dev_dbg(&p->pdev->dev, "bound drc %x to %pR\n", p->drc_index, &p->res);
  74
  75         return 0;
  76 }
  77
  78 static int drc_pmem_unbind(struct papr_scm_priv *p)
  79 {
  80         unsigned long ret[PLPAR_HCALL_BUFSIZE];
  81         uint64_t rc, token;
  82
  83         token = 0;
  84
  85         /* NB: unbind has the same retry requirements mentioned above */
  86         do {
  87                 rc = plpar_hcall(H_SCM_UNBIND_MEM, ret, p->drc_index,
  88                                 p->bound_addr, p->blocks, token);
  89                 token = ret[0];
  90                 cond_resched();
  91         } while (rc == H_BUSY);
  92
  93         if (rc)
  94                 dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
  95
  96         return !!rc;
  97 }
  98
  99 static int papr_scm_meta_get(struct papr_scm_priv *p,
 100                         struct nd_cmd_get_config_data_hdr *hdr)
 101 {
 102         unsigned long data[PLPAR_HCALL_BUFSIZE];
 103         int64_t ret;
 104
 105         if (hdr->in_offset >= p->metadata_size || hdr->in_length != 1)
 106                 return -EINVAL;
 107
 108         ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
 109                         hdr->in_offset, 1);
 110
 111         if (ret == H_PARAMETER) /* bad DRC index */
 112                 return -ENODEV;
 113         if (ret)
 114                 return -EINVAL; /* other invalid parameter */
 115
 116         hdr->out_buf[0] = data[0] & 0xff;
 117
 118         return 0;
 119 }
 120
 121 static int papr_scm_meta_set(struct papr_scm_priv *p,
 122                         struct nd_cmd_set_config_hdr *hdr)
 123 {
 124         int64_t ret;
 125
 126         if (hdr->in_offset >= p->metadata_size || hdr->in_length != 1)
 127                 return -EINVAL;
 128
 129         ret = plpar_hcall_norets(H_SCM_WRITE_METADATA,
 130                         p->drc_index, hdr->in_offset, hdr->in_buf[0], 1);
 131
 132         if (ret == H_PARAMETER) /* bad DRC index */
 133                 return -ENODEV;
 134         if (ret)
 135                 return -EINVAL; /* other invalid parameter */
 136
 137         return 0;
 138 }
 139
 140 int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 141                 unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
 142 {
 143         struct nd_cmd_get_config_size *get_size_hdr;
 144         struct papr_scm_priv *p;
 145
 146         /* Only dimm-specific calls are supported atm */
 147         if (!nvdimm)
 148                 return -EINVAL;
 149
 150         p = nvdimm_provider_data(nvdimm);
 151
 152         switch (cmd) {
 153         case ND_CMD_GET_CONFIG_SIZE:
 154                 get_size_hdr = buf;
 155
 156                 get_size_hdr->status = 0;
 157                 get_size_hdr->max_xfer = 1;
 158                 get_size_hdr->config_size = p->metadata_size;
 159                 *cmd_rc = 0;
 160                 break;
 161
 162         case ND_CMD_GET_CONFIG_DATA:
 163                 *cmd_rc = papr_scm_meta_get(p, buf);
 164                 break;
 165
 166         case ND_CMD_SET_CONFIG_DATA:
 167                 *cmd_rc = papr_scm_meta_set(p, buf);
 168                 break;
 169
 170         default:
 171                 return -EINVAL;
 172         }
 173
 174         dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
 175
 176         return 0;
 177 }
 178
 179 static const struct attribute_group *region_attr_groups[] = {
 180         &nd_region_attribute_group,
 181         &nd_device_attribute_group,
 182         &nd_mapping_attribute_group,
 183         &nd_numa_attribute_group,
 184         NULL,
 185 };
 186
 187 static const struct attribute_group *bus_attr_groups[] = {
 188         &nvdimm_bus_attribute_group,
 189         NULL,
 190 };
 191
 192 static const struct attribute_group *papr_scm_dimm_groups[] = {
 193         &nvdimm_attribute_group,
 194         &nd_device_attribute_group,
 195         NULL,
 196 };
 197
 198 static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
 199 {
 200         struct device *dev = &p->pdev->dev;
 201         struct nd_mapping_desc mapping;
 202         struct nd_region_desc ndr_desc;
 203         unsigned long dimm_flags;
 204
 205         p->bus_desc.ndctl = papr_scm_ndctl;
 206         p->bus_desc.module = THIS_MODULE;
 207         p->bus_desc.of_node = p->pdev->dev.of_node;
 208         p->bus_desc.attr_groups = bus_attr_groups;
 209         p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);
 210
 211         if (!p->bus_desc.provider_name)
 212                 return -ENOMEM;
 213
 214         p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
 215         if (!p->bus) {
 216                 dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
 217                 return -ENXIO;
 218         }
 219
 220         dimm_flags = 0;
 221         set_bit(NDD_ALIASING, &dimm_flags);
 222
 223         p->nvdimm = nvdimm_create(p->bus, p, papr_scm_dimm_groups,
 224                                 dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
 225         if (!p->nvdimm) {
 226                 dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
 227                 goto err;
 228         }
 229
 230         if (nvdimm_bus_check_dimm_count(p->bus, 1))
 231                 goto err;
 232
 233         /* now add the region */
 234
 235         memset(&mapping, 0, sizeof(mapping));
 236         mapping.nvdimm = p->nvdimm;
 237         mapping.start = 0;
 238         mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
 239
 240         memset(&ndr_desc, 0, sizeof(ndr_desc));
 241         ndr_desc.attr_groups = region_attr_groups;
 242         ndr_desc.numa_node = dev_to_node(&p->pdev->dev);
 243         ndr_desc.target_node = ndr_desc.numa_node;
 244         ndr_desc.res = &p->res;
 245         ndr_desc.of_node = p->dn;
 246         ndr_desc.provider_data = p;
 247         ndr_desc.mapping = &mapping;
 248         ndr_desc.num_mappings = 1;
 249         ndr_desc.nd_set = &p->nd_set;
 250         set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
 251
 252         if (p->is_volatile)
 253                 p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc);
 254         else
 255                 p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
 256         if (!p->region) {
 257                 dev_err(dev, "Error registering region %pR from %pOF\n",
 258                                 ndr_desc.res, p->dn);
 259                 goto err;
 260         }
 261
 262         return 0;
 263
 264 err:    nvdimm_bus_unregister(p->bus);
 265         kfree(p->bus_desc.provider_name);
 266         return -ENXIO;
 267 }
 268
 269 static int papr_scm_probe(struct platform_device *pdev)
 270 {
 271         struct device_node *dn = pdev->dev.of_node;
 272         u32 drc_index, metadata_size;
 273         u64 blocks, block_size;
 274         struct papr_scm_priv *p;
 275         const char *uuid_str;
 276         u64 uuid[2];
 277         int rc;
 278
 279         /* check we have all the required DT properties */
 280         if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
 281                 dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
 282                 return -ENODEV;
 283         }
 284
 285         if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
 286                 dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
 287                 return -ENODEV;
 288         }
 289
 290         if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
 291                 dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
 292                 return -ENODEV;
 293         }
 294
 295         if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
 296                 dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
 297                 return -ENODEV;
 298         }
 299
 300
 301         p = kzalloc(sizeof(*p), GFP_KERNEL);
 302         if (!p)
 303                 return -ENOMEM;
 304
 305         /* optional DT properties */
 306         of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
 307
 308         p->dn = dn;
 309         p->drc_index = drc_index;
 310         p->block_size = block_size;
 311         p->blocks = blocks;
 312         p->is_volatile = !of_property_read_bool(dn, "ibm,cache-flush-required");
 313
 314         /* We just need to ensure that set cookies are unique across */
 315         uuid_parse(uuid_str, (uuid_t *) uuid);
 316         p->nd_set.cookie1 = uuid[0];
 317         p->nd_set.cookie2 = uuid[1];
 318
 319         /* might be zero */
 320         p->metadata_size = metadata_size;
 321         p->pdev = pdev;
 322
 323         /* request the hypervisor to bind this region to somewhere in memory */
 324         rc = drc_pmem_bind(p);
 325         if (rc)
 326                 goto err;
 327
 328         /* setup the resource for the newly bound range */
 329         p->res.start = p->bound_addr;
 330         p->res.end   = p->bound_addr + p->blocks * p->block_size - 1;
 331         p->res.name  = pdev->name;
 332         p->res.flags = IORESOURCE_MEM;
 333
 334         rc = papr_scm_nvdimm_init(p);
 335         if (rc)
 336                 goto err2;
 337
 338         platform_set_drvdata(pdev, p);
 339
 340         return 0;
 341
 342 err2:   drc_pmem_unbind(p);
 343 err:    kfree(p);
 344         return rc;
 345 }
 346
 347 static int papr_scm_remove(struct platform_device *pdev)
 348 {
 349         struct papr_scm_priv *p = platform_get_drvdata(pdev);
 350
 351         nvdimm_bus_unregister(p->bus);
 352         drc_pmem_unbind(p);
 353         kfree(p);
 354
 355         return 0;
 356 }
 357
 358 static const struct of_device_id papr_scm_match[] = {
 359         { .compatible = "ibm,pmemory" },
 360         { },
 361 };
 362
 363 static struct platform_driver papr_scm_driver = {
 364         .probe = papr_scm_probe,
 365         .remove = papr_scm_remove,
 366         .driver = {
 367                 .name = "papr_scm",
 368                 .owner = THIS_MODULE,
 369                 .of_match_table = papr_scm_match,
 370         },
 371 };
 372
 373 module_platform_driver(papr_scm_driver);
 374 MODULE_DEVICE_TABLE(of, papr_scm_match);
 375 MODULE_LICENSE("GPL");
 376 MODULE_AUTHOR("IBM Corporation");