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");