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
  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");