src/linux-pmem.c

   1 /*
   2  * libefiboot - library for the manipulation of EFI boot variables
   3  * Copyright 2012-2018 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public License as
   7  * published by the Free Software Foundation; either version 2.1 of the
   8  * License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, see
  17  * <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "fix_coverity.h"
  22
  23 #include <errno.h>
  24 #include <fcntl.h>
  25 #include <inttypes.h>
  26 #include <stdint.h>
  27 #include <unistd.h>
  28
  29 #include "efiboot.h"
  30
  31 /*
  32  * support NVDIMM-P (pmem / btt) devices
  33  * (does not include NVDIMM-${ANYTHING_ELSE})
  34  *
  35  * /sys/dev/block/$major:$minor looks like:
  36  * 259:0 -> ../../devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/region9/btt9.0/block/pmem9s
  37  * 259:1 -> ../../devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/region11/btt11.0/block/pmem11s
  38  * 259:3 -> ../../devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/region11/btt11.0/block/pmem11s/pmem11s1
  39  *
  40  * /sys/dev/block/259:0/device looks like:
  41  * device -> ../../../btt9.0
  42  * /sys/dev/block/259:1/device looks like:
  43  * device -> ../../../btt11.0
  44  *
  45  * /sys/dev/block/259:1/partition looks like:
  46  * $ cat partition
  47  * 1
  48  *
  49  * /sys/dev/block/259:0/uuid looks like:
  50  * $ cat uuid
  51  * 6e54091e-7476-47ac-824b-b6dd69878661
  52  *
  53  * pmem12s -> ../devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/region12/btt12.1/block/pmem12s
  54  * dev: 259:0
  55  * device -> ../../../btt12.1
  56  * device/uuid: 0cee166e-dd56-4bc2-99d2-2544b69025b8
  57  * 259:0 -> ../../devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/region12/btt12.1/block/pmem12s
  58  *
  59  * pmem12.1s -> ../devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/region12/btt12.2/block/pmem12.1s
  60  * dev: 259:1
  61  * device -> ../../../btt12.2
  62  * device/uuid: 78d94521-91f7-47db-b3a7-51b764281940
  63  * 259:1 -> ../../devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/region12/btt12.2/block/pmem12.1s
  64  *
  65  * pmem12.2 -> ../devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/region12/pfn12.1/block/pmem12.2
  66  * dev: 259:2
  67  * device -> ../../../pfn12.1
  68  * device/uuid: 829c5205-89a5-4581-9819-df7d7754c622
  69  * 259:2 -> ../../devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/region12/pfn12.1/block/pmem12.2
  70  */
  71
  72 static ssize_t
  73 parse_pmem(struct device *dev, const char *current, const char *root UNUSED)
  74 {
  75         uint8_t *filebuf = NULL;
  76         uint8_t system, sysbus, acpi_id;
  77         uint16_t pnp_id;
  78         int ndbus, region, btt_region_id, btt_id, rc, pos;
  79         char *namespace = NULL;
  80
  81         debug("entry");
  82
  83         if (!strcmp(dev->driver, "nd_pmem")) {
  84                 ;
  85 #if 0 /* dunno */
  86         } else if (!strcmp(dev->driver, "nd_blk")) {
  87                 /* dunno */
  88                 dev->inteface_type = scsi;
  89 #endif
  90         } else {
  91                 /*
  92                  * not a pmem device
  93                  */
  94                 return 0;
  95         }
  96
  97         /*
  98          * We're not actually using any of the values here except pos (our
  99          * return value), but rather just being paranoid that this is the sort
 100          * of device we care about.
 101          *
 102          * 259:0 -> ../../devices/LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/region12/btt12.1/block/pmem12s
 103          */
 104         rc = sscanf(current,
 105                     "../../devices/LNXSYSTM:%hhx/LNXSYBUS:%hhx/ACPI%hx:%hhx/ndbus%d/region%d/btt%d.%d/%n",
 106                     &system, &sysbus, &pnp_id, &acpi_id, &ndbus, &region,
 107                     &btt_region_id, &btt_id, &pos);
 108         if (rc < 8)
 109                 return 0;
 110
 111         /*
 112          * but the UUID we really do need to have.
 113          */
 114         rc = read_sysfs_file(&filebuf,
 115                              "class/block/%s/device/namespace", dev->disk_name);
 116         if ((rc < 0 && errno == ENOENT) || filebuf == NULL)
 117                 return -1;
 118
 119         rc = sscanf((char *)filebuf, "%ms[^\n]\n", &namespace);
 120         if (rc != 1 || namespace == NULL)
 121                 return -1;
 122
 123         filebuf = NULL;
 124         debug("nvdimm namespace is \"%s\"", namespace);
 125         rc = read_sysfs_file(&filebuf, "bus/nd/devices/%s/uuid", namespace);
 126         free(namespace);
 127         if (rc < 0 || filebuf == NULL)
 128                 return -1;
 129
 130         rc = efi_str_to_guid((char *)filebuf,
 131                              &dev->nvdimm_info.namespace_label);
 132         if (rc < 0)
 133                 return -1;
 134
 135         filebuf = NULL;
 136         rc = read_sysfs_file(&filebuf, "class/block/%s/device/uuid",
 137                              dev->disk_name);
 138         if (rc < 0 || filebuf == NULL)
 139                 return -1;
 140
 141         rc = efi_str_to_guid((char *)filebuf,
 142                              &dev->nvdimm_info.nvdimm_label);
 143         if (rc < 0)
 144                 return -1;
 145
 146         /*
 147          * Right now it's not clear what encoding NVDIMM($uuid) gets in the
 148          * binary format, so this will be in the mixed endian format EFI GUIDs
 149          * are in (33221100-1100-1100-0011-223344556677) unless you set this
 150          * variable.
 151          */
 152         if (getenv("LIBEFIBOOT_SWIZZLE_PMEM_UUID") != NULL) {
 153                 swizzle_guid_to_uuid(&dev->nvdimm_info.namespace_label);
 154                 swizzle_guid_to_uuid(&dev->nvdimm_info.nvdimm_label);
 155         }
 156
 157         dev->interface_type = nd_pmem;
 158
 159         return pos;
 160 }
 161
 162 static ssize_t
 163 dp_create_pmem(struct device *dev,
 164                uint8_t *buf, ssize_t size, ssize_t off)
 165 {
 166         ssize_t sz, sz1;
 167
 168         debug("entry");
 169
 170         sz = efidp_make_nvdimm(buf + off, size ? size - off : 0,
 171                                &dev->nvdimm_info.namespace_label);
 172         if (sz < 0)
 173                 return sz;
 174         off += sz;
 175         sz1 = efidp_make_nvdimm(buf + off, size ? size - off : 0,
 176                                 &dev->nvdimm_info.nvdimm_label);
 177         if (sz1 < 0)
 178                 return sz1;
 179
 180         return sz + sz1;
 181 }
 182
 183 enum interface_type pmem_iftypes[] = { nd_pmem, unknown };
 184
 185 struct dev_probe HIDDEN pmem_parser = {
 186         .name = "pmem",
 187         .iftypes = pmem_iftypes,
 188         .flags = DEV_PROVIDES_ROOT|DEV_PROVIDES_HD,
 189         .parse = parse_pmem,
 190         .create = dp_create_pmem,
 191 };