drivers/platform/x86/intel/pmt/telemetry.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Intel Platform Monitory Technology Telemetry driver
   4  *
   5  * Copyright (c) 2020, Intel Corporation.
   6  * All Rights Reserved.
   7  *
   8  * Author: "David E. Box" <david.e.box@linux.intel.com>
   9  */
  10
  11 #include <linux/auxiliary_bus.h>
  12 #include <linux/intel_vsec.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/pci.h>
  16 #include <linux/slab.h>
  17 #include <linux/uaccess.h>
  18 #include <linux/overflow.h>
  19
  20 #include "class.h"
  21
  22 #define TELEM_SIZE_OFFSET       0x0
  23 #define TELEM_GUID_OFFSET       0x4
  24 #define TELEM_BASE_OFFSET       0x8
  25 #define TELEM_ACCESS(v)         ((v) & GENMASK(3, 0))
  26 #define TELEM_TYPE(v)           (((v) & GENMASK(7, 4)) >> 4)
  27 /* size is in bytes */
  28 #define TELEM_SIZE(v)           (((v) & GENMASK(27, 12)) >> 10)
  29
  30 /* Used by client hardware to identify a fixed telemetry entry*/
  31 #define TELEM_CLIENT_FIXED_BLOCK_GUID   0x10000000
  32
  33 #define NUM_BYTES_QWORD(v)      ((v) << 3)
  34 #define SAMPLE_ID_OFFSET(v)     ((v) << 3)
  35
  36 #define NUM_BYTES_DWORD(v)      ((v) << 2)
  37 #define SAMPLE_ID_OFFSET32(v)   ((v) << 2)
  38
  39 /* Protects access to the xarray of telemetry endpoint handles */
  40 static DEFINE_MUTEX(ep_lock);
  41
  42 enum telem_type {
  43         TELEM_TYPE_PUNIT = 0,
  44         TELEM_TYPE_CRASHLOG,
  45         TELEM_TYPE_PUNIT_FIXED,
  46 };
  47
  48 struct pmt_telem_priv {
  49         int                             num_entries;
  50         struct intel_pmt_entry          entry[];
  51 };
  52
  53 static bool pmt_telem_region_overlaps(struct intel_pmt_entry *entry,
  54                                       struct device *dev)
  55 {
  56         u32 guid = readl(entry->disc_table + TELEM_GUID_OFFSET);
  57
  58         if (intel_pmt_is_early_client_hw(dev)) {
  59                 u32 type = TELEM_TYPE(readl(entry->disc_table));
  60
  61                 if ((type == TELEM_TYPE_PUNIT_FIXED) ||
  62                     (guid == TELEM_CLIENT_FIXED_BLOCK_GUID))
  63                         return true;
  64         }
  65
  66         return false;
  67 }
  68
  69 static int pmt_telem_header_decode(struct intel_pmt_entry *entry,
  70                                    struct device *dev)
  71 {
  72         void __iomem *disc_table = entry->disc_table;
  73         struct intel_pmt_header *header = &entry->header;
  74
  75         if (pmt_telem_region_overlaps(entry, dev))
  76                 return 1;
  77
  78         header->access_type = TELEM_ACCESS(readl(disc_table));
  79         header->guid = readl(disc_table + TELEM_GUID_OFFSET);
  80         header->base_offset = readl(disc_table + TELEM_BASE_OFFSET);
  81
  82         /* Size is measured in DWORDS, but accessor returns bytes */
  83         header->size = TELEM_SIZE(readl(disc_table));
  84
  85         /*
  86          * Some devices may expose non-functioning entries that are
  87          * reserved for future use. They have zero size. Do not fail
  88          * probe for these. Just ignore them.
  89          */
  90         if (header->size == 0 || header->access_type == 0xF)
  91                 return 1;
  92
  93         return 0;
  94 }
  95
  96 static int pmt_telem_add_endpoint(struct intel_vsec_device *ivdev,
  97                                   struct intel_pmt_entry *entry)
  98 {
  99         struct telem_endpoint *ep;
 100
 101         /* Endpoint lifetimes are managed by kref, not devres */
 102         entry->ep = kzalloc(sizeof(*(entry->ep)), GFP_KERNEL);
 103         if (!entry->ep)
 104                 return -ENOMEM;
 105
 106         ep = entry->ep;
 107         ep->pcidev = ivdev->pcidev;
 108         ep->header.access_type = entry->header.access_type;
 109         ep->header.guid = entry->header.guid;
 110         ep->header.base_offset = entry->header.base_offset;
 111         ep->header.size = entry->header.size;
 112         ep->base = entry->base;
 113         ep->present = true;
 114         ep->cb = ivdev->priv_data;
 115
 116         kref_init(&ep->kref);
 117
 118         return 0;
 119 }
 120
 121 static DEFINE_XARRAY_ALLOC(telem_array);
 122 static struct intel_pmt_namespace pmt_telem_ns = {
 123         .name = "telem",
 124         .xa = &telem_array,
 125         .pmt_header_decode = pmt_telem_header_decode,
 126         .pmt_add_endpoint = pmt_telem_add_endpoint,
 127 };
 128
 129 /* Called when all users unregister and the device is removed */
 130 static void pmt_telem_ep_release(struct kref *kref)
 131 {
 132         struct telem_endpoint *ep;
 133
 134         ep = container_of(kref, struct telem_endpoint, kref);
 135         kfree(ep);
 136 }
 137
 138 unsigned long pmt_telem_get_next_endpoint(unsigned long start)
 139 {
 140         struct intel_pmt_entry *entry;
 141         unsigned long found_idx;
 142
 143         mutex_lock(&ep_lock);
 144         xa_for_each_start(&telem_array, found_idx, entry, start) {
 145                 /*
 146                  * Return first found index after start.
 147                  * 0 is not valid id.
 148                  */
 149                 if (found_idx > start)
 150                         break;
 151         }
 152         mutex_unlock(&ep_lock);
 153
 154         return found_idx == start ? 0 : found_idx;
 155 }
 156 EXPORT_SYMBOL_NS_GPL(pmt_telem_get_next_endpoint, "INTEL_PMT_TELEMETRY");
 157
 158 struct telem_endpoint *pmt_telem_register_endpoint(int devid)
 159 {
 160         struct intel_pmt_entry *entry;
 161         unsigned long index = devid;
 162
 163         mutex_lock(&ep_lock);
 164         entry = xa_find(&telem_array, &index, index, XA_PRESENT);
 165         if (!entry) {
 166                 mutex_unlock(&ep_lock);
 167                 return ERR_PTR(-ENXIO);
 168         }
 169
 170         kref_get(&entry->ep->kref);
 171         mutex_unlock(&ep_lock);
 172
 173         return entry->ep;
 174 }
 175 EXPORT_SYMBOL_NS_GPL(pmt_telem_register_endpoint, "INTEL_PMT_TELEMETRY");
 176
 177 void pmt_telem_unregister_endpoint(struct telem_endpoint *ep)
 178 {
 179         kref_put(&ep->kref, pmt_telem_ep_release);
 180 }
 181 EXPORT_SYMBOL_NS_GPL(pmt_telem_unregister_endpoint, "INTEL_PMT_TELEMETRY");
 182
 183 int pmt_telem_get_endpoint_info(int devid, struct telem_endpoint_info *info)
 184 {
 185         struct intel_pmt_entry *entry;
 186         unsigned long index = devid;
 187         int err = 0;
 188
 189         if (!info)
 190                 return -EINVAL;
 191
 192         mutex_lock(&ep_lock);
 193         entry = xa_find(&telem_array, &index, index, XA_PRESENT);
 194         if (!entry) {
 195                 err = -ENXIO;
 196                 goto unlock;
 197         }
 198
 199         info->pdev = entry->ep->pcidev;
 200         info->header = entry->ep->header;
 201
 202 unlock:
 203         mutex_unlock(&ep_lock);
 204         return err;
 205
 206 }
 207 EXPORT_SYMBOL_NS_GPL(pmt_telem_get_endpoint_info, "INTEL_PMT_TELEMETRY");
 208
 209 int pmt_telem_read(struct telem_endpoint *ep, u32 id, u64 *data, u32 count)
 210 {
 211         u32 offset, size;
 212
 213         if (!ep->present)
 214                 return -ENODEV;
 215
 216         offset = SAMPLE_ID_OFFSET(id);
 217         size = ep->header.size;
 218
 219         if (offset + NUM_BYTES_QWORD(count) > size)
 220                 return -EINVAL;
 221
 222         pmt_telem_read_mmio(ep->pcidev, ep->cb, ep->header.guid, data, ep->base, offset,
 223                             NUM_BYTES_QWORD(count));
 224
 225         return ep->present ? 0 : -EPIPE;
 226 }
 227 EXPORT_SYMBOL_NS_GPL(pmt_telem_read, "INTEL_PMT_TELEMETRY");
 228
 229 int pmt_telem_read32(struct telem_endpoint *ep, u32 id, u32 *data, u32 count)
 230 {
 231         u32 offset, size;
 232
 233         if (!ep->present)
 234                 return -ENODEV;
 235
 236         offset = SAMPLE_ID_OFFSET32(id);
 237         size = ep->header.size;
 238
 239         if (offset + NUM_BYTES_DWORD(count) > size)
 240                 return -EINVAL;
 241
 242         memcpy_fromio(data, ep->base + offset, NUM_BYTES_DWORD(count));
 243
 244         return ep->present ? 0 : -EPIPE;
 245 }
 246 EXPORT_SYMBOL_NS_GPL(pmt_telem_read32, "INTEL_PMT_TELEMETRY");
 247
 248 struct telem_endpoint *
 249 pmt_telem_find_and_register_endpoint(struct pci_dev *pcidev, u32 guid, u16 pos)
 250 {
 251         int devid = 0;
 252         int inst = 0;
 253         int err = 0;
 254
 255         while ((devid = pmt_telem_get_next_endpoint(devid))) {
 256                 struct telem_endpoint_info ep_info;
 257
 258                 err = pmt_telem_get_endpoint_info(devid, &ep_info);
 259                 if (err)
 260                         return ERR_PTR(err);
 261
 262                 if (ep_info.header.guid == guid && ep_info.pdev == pcidev) {
 263                         if (inst == pos)
 264                                 return pmt_telem_register_endpoint(devid);
 265                         ++inst;
 266                 }
 267         }
 268
 269         return ERR_PTR(-ENXIO);
 270 }
 271 EXPORT_SYMBOL_NS_GPL(pmt_telem_find_and_register_endpoint, "INTEL_PMT_TELEMETRY");
 272
 273 static void pmt_telem_remove(struct auxiliary_device *auxdev)
 274 {
 275         struct pmt_telem_priv *priv = auxiliary_get_drvdata(auxdev);
 276         int i;
 277
 278         mutex_lock(&ep_lock);
 279         for (i = 0; i < priv->num_entries; i++) {
 280                 struct intel_pmt_entry *entry = &priv->entry[i];
 281
 282                 kref_put(&entry->ep->kref, pmt_telem_ep_release);
 283                 intel_pmt_dev_destroy(entry, &pmt_telem_ns);
 284         }
 285         mutex_unlock(&ep_lock);
 286 };
 287
 288 static int pmt_telem_probe(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id)
 289 {
 290         struct intel_vsec_device *intel_vsec_dev = auxdev_to_ivdev(auxdev);
 291         struct pmt_telem_priv *priv;
 292         size_t size;
 293         int i, ret;
 294
 295         size = struct_size(priv, entry, intel_vsec_dev->num_resources);
 296         priv = devm_kzalloc(&auxdev->dev, size, GFP_KERNEL);
 297         if (!priv)
 298                 return -ENOMEM;
 299
 300         auxiliary_set_drvdata(auxdev, priv);
 301
 302         for (i = 0; i < intel_vsec_dev->num_resources; i++) {
 303                 struct intel_pmt_entry *entry = &priv->entry[priv->num_entries];
 304
 305                 mutex_lock(&ep_lock);
 306                 ret = intel_pmt_dev_create(entry, &pmt_telem_ns, intel_vsec_dev, i);
 307                 mutex_unlock(&ep_lock);
 308                 if (ret < 0)
 309                         goto abort_probe;
 310                 if (ret)
 311                         continue;
 312
 313                 priv->num_entries++;
 314         }
 315
 316         return 0;
 317 abort_probe:
 318         pmt_telem_remove(auxdev);
 319         return ret;
 320 }
 321
 322 static const struct auxiliary_device_id pmt_telem_id_table[] = {
 323         { .name = "intel_vsec.telemetry" },
 324         {}
 325 };
 326 MODULE_DEVICE_TABLE(auxiliary, pmt_telem_id_table);
 327
 328 static struct auxiliary_driver pmt_telem_aux_driver = {
 329         .id_table       = pmt_telem_id_table,
 330         .remove         = pmt_telem_remove,
 331         .probe          = pmt_telem_probe,
 332 };
 333
 334 static int __init pmt_telem_init(void)
 335 {
 336         return auxiliary_driver_register(&pmt_telem_aux_driver);
 337 }
 338 module_init(pmt_telem_init);
 339
 340 static void __exit pmt_telem_exit(void)
 341 {
 342         auxiliary_driver_unregister(&pmt_telem_aux_driver);
 343         xa_destroy(&telem_array);
 344 }
 345 module_exit(pmt_telem_exit);
 346
 347 MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
 348 MODULE_DESCRIPTION("Intel PMT Telemetry driver");
 349 MODULE_LICENSE("GPL v2");
 350 MODULE_IMPORT_NS("INTEL_PMT");