drivers/platform/x86/intel/pmt/class.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: "Alexander Duyck" <[email protected]>
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/intel_vsec.h>
  13 #include <linux/io-64-nonatomic-lo-hi.h>
  14 #include <linux/module.h>
  15 #include <linux/mm.h>
  16 #include <linux/pci.h>
  17
  18 #include "class.h"
  19
  20 #define PMT_XA_START            1
  21 #define PMT_XA_MAX              INT_MAX
  22 #define PMT_XA_LIMIT            XA_LIMIT(PMT_XA_START, PMT_XA_MAX)
  23 #define GUID_SPR_PUNIT          0x9956f43f
  24
  25 bool intel_pmt_is_early_client_hw(struct device *dev)
  26 {
  27         struct intel_vsec_device *ivdev = dev_to_ivdev(dev);
  28
  29         /*
  30          * Early implementations of PMT on client platforms have some
  31          * differences from the server platforms (which use the Out Of Band
  32          * Management Services Module OOBMSM).
  33          */
  34         return !!(ivdev->quirks & VSEC_QUIRK_EARLY_HW);
  35 }
  36 EXPORT_SYMBOL_NS_GPL(intel_pmt_is_early_client_hw, INTEL_PMT);
  37
  38 static inline int
  39 pmt_memcpy64_fromio(void *to, const u64 __iomem *from, size_t count)
  40 {
  41         int i, remain;
  42         u64 *buf = to;
  43
  44         if (!IS_ALIGNED((unsigned long)from, 8))
  45                 return -EFAULT;
  46
  47         for (i = 0; i < count/8; i++)
  48                 buf[i] = readq(&from[i]);
  49
  50         /* Copy any remaining bytes */
  51         remain = count % 8;
  52         if (remain) {
  53                 u64 tmp = readq(&from[i]);
  54
  55                 memcpy(&buf[i], &tmp, remain);
  56         }
  57
  58         return count;
  59 }
  60
  61 int pmt_telem_read_mmio(struct pci_dev *pdev, struct pmt_callbacks *cb, u32 guid, void *buf,
  62                         void __iomem *addr, u32 count)
  63 {
  64         if (cb && cb->read_telem)
  65                 return cb->read_telem(pdev, guid, buf, count);
  66
  67         if (guid == GUID_SPR_PUNIT)
  68                 /* PUNIT on SPR only supports aligned 64-bit read */
  69                 return pmt_memcpy64_fromio(buf, addr, count);
  70
  71         memcpy_fromio(buf, addr, count);
  72
  73         return count;
  74 }
  75 EXPORT_SYMBOL_NS_GPL(pmt_telem_read_mmio, INTEL_PMT);
  76
  77 /*
  78  * sysfs
  79  */
  80 static ssize_t
  81 intel_pmt_read(struct file *filp, struct kobject *kobj,
  82                struct bin_attribute *attr, char *buf, loff_t off,
  83                size_t count)
  84 {
  85         struct intel_pmt_entry *entry = container_of(attr,
  86                                                      struct intel_pmt_entry,
  87                                                      pmt_bin_attr);
  88
  89         if (off < 0)
  90                 return -EINVAL;
  91
  92         if (off >= entry->size)
  93                 return 0;
  94
  95         if (count > entry->size - off)
  96                 count = entry->size - off;
  97
  98         count = pmt_telem_read_mmio(entry->ep->pcidev, entry->cb, entry->header.guid, buf,
  99                                     entry->base + off, count);
 100
 101         return count;
 102 }
 103
 104 static int
 105 intel_pmt_mmap(struct file *filp, struct kobject *kobj,
 106                 struct bin_attribute *attr, struct vm_area_struct *vma)
 107 {
 108         struct intel_pmt_entry *entry = container_of(attr,
 109                                                      struct intel_pmt_entry,
 110                                                      pmt_bin_attr);
 111         unsigned long vsize = vma->vm_end - vma->vm_start;
 112         struct device *dev = kobj_to_dev(kobj);
 113         unsigned long phys = entry->base_addr;
 114         unsigned long pfn = PFN_DOWN(phys);
 115         unsigned long psize;
 116
 117         if (vma->vm_flags & (VM_WRITE | VM_MAYWRITE))
 118                 return -EROFS;
 119
 120         psize = (PFN_UP(entry->base_addr + entry->size) - pfn) * PAGE_SIZE;
 121         if (vsize > psize) {
 122                 dev_err(dev, "Requested mmap size is too large\n");
 123                 return -EINVAL;
 124         }
 125
 126         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 127         if (io_remap_pfn_range(vma, vma->vm_start, pfn,
 128                 vsize, vma->vm_page_prot))
 129                 return -EAGAIN;
 130
 131         return 0;
 132 }
 133
 134 static ssize_t
 135 guid_show(struct device *dev, struct device_attribute *attr, char *buf)
 136 {
 137         struct intel_pmt_entry *entry = dev_get_drvdata(dev);
 138
 139         return sprintf(buf, "0x%x\n", entry->guid);
 140 }
 141 static DEVICE_ATTR_RO(guid);
 142
 143 static ssize_t size_show(struct device *dev, struct device_attribute *attr,
 144                          char *buf)
 145 {
 146         struct intel_pmt_entry *entry = dev_get_drvdata(dev);
 147
 148         return sprintf(buf, "%zu\n", entry->size);
 149 }
 150 static DEVICE_ATTR_RO(size);
 151
 152 static ssize_t
 153 offset_show(struct device *dev, struct device_attribute *attr, char *buf)
 154 {
 155         struct intel_pmt_entry *entry = dev_get_drvdata(dev);
 156
 157         return sprintf(buf, "%lu\n", offset_in_page(entry->base_addr));
 158 }
 159 static DEVICE_ATTR_RO(offset);
 160
 161 static struct attribute *intel_pmt_attrs[] = {
 162         &dev_attr_guid.attr,
 163         &dev_attr_size.attr,
 164         &dev_attr_offset.attr,
 165         NULL
 166 };
 167 ATTRIBUTE_GROUPS(intel_pmt);
 168
 169 static struct class intel_pmt_class = {
 170         .name = "intel_pmt",
 171         .dev_groups = intel_pmt_groups,
 172 };
 173
 174 static int intel_pmt_populate_entry(struct intel_pmt_entry *entry,
 175                                     struct intel_vsec_device *ivdev,
 176                                     struct resource *disc_res)
 177 {
 178         struct pci_dev *pci_dev = ivdev->pcidev;
 179         struct device *dev = &ivdev->auxdev.dev;
 180         struct intel_pmt_header *header = &entry->header;
 181         u8 bir;
 182
 183         /*
 184          * The base offset should always be 8 byte aligned.
 185          *
 186          * For non-local access types the lower 3 bits of base offset
 187          * contains the index of the base address register where the
 188          * telemetry can be found.
 189          */
 190         bir = GET_BIR(header->base_offset);
 191
 192         /* Local access and BARID only for now */
 193         switch (header->access_type) {
 194         case ACCESS_LOCAL:
 195                 if (bir) {
 196                         dev_err(dev,
 197                                 "Unsupported BAR index %d for access type %d\n",
 198                                 bir, header->access_type);
 199                         return -EINVAL;
 200                 }
 201                 /*
 202                  * For access_type LOCAL, the base address is as follows:
 203                  * base address = end of discovery region + base offset
 204                  */
 205                 entry->base_addr = disc_res->end + 1 + header->base_offset;
 206
 207                 /*
 208                  * Some hardware use a different calculation for the base address
 209                  * when access_type == ACCESS_LOCAL. On the these systems
 210                  * ACCCESS_LOCAL refers to an address in the same BAR as the
 211                  * header but at a fixed offset. But as the header address was
 212                  * supplied to the driver, we don't know which BAR it was in.
 213                  * So search for the bar whose range includes the header address.
 214                  */
 215                 if (intel_pmt_is_early_client_hw(dev)) {
 216                         int i;
 217
 218                         entry->base_addr = 0;
 219                         for (i = 0; i < 6; i++)
 220                                 if (disc_res->start >= pci_resource_start(pci_dev, i) &&
 221                                    (disc_res->start <= pci_resource_end(pci_dev, i))) {
 222                                         entry->base_addr = pci_resource_start(pci_dev, i) +
 223                                                            header->base_offset;
 224                                         break;
 225                                 }
 226                         if (!entry->base_addr)
 227                                 return -EINVAL;
 228                 }
 229
 230                 break;
 231         case ACCESS_BARID:
 232                 /* Use the provided base address if it exists */
 233                 if (ivdev->base_addr) {
 234                         entry->base_addr = ivdev->base_addr +
 235                                    GET_ADDRESS(header->base_offset);
 236                         break;
 237                 }
 238
 239                 /*
 240                  * If another BAR was specified then the base offset
 241                  * represents the offset within that BAR. SO retrieve the
 242                  * address from the parent PCI device and add offset.
 243                  */
 244                 entry->base_addr = pci_resource_start(pci_dev, bir) +
 245                                    GET_ADDRESS(header->base_offset);
 246                 break;
 247         default:
 248                 dev_err(dev, "Unsupported access type %d\n",
 249                         header->access_type);
 250                 return -EINVAL;
 251         }
 252
 253         entry->guid = header->guid;
 254         entry->size = header->size;
 255         entry->cb = ivdev->priv_data;
 256
 257         return 0;
 258 }
 259
 260 static int intel_pmt_dev_register(struct intel_pmt_entry *entry,
 261                                   struct intel_pmt_namespace *ns,
 262                                   struct device *parent)
 263 {
 264         struct intel_vsec_device *ivdev = dev_to_ivdev(parent);
 265         struct resource res = {0};
 266         struct device *dev;
 267         int ret;
 268
 269         ret = xa_alloc(ns->xa, &entry->devid, entry, PMT_XA_LIMIT, GFP_KERNEL);
 270         if (ret)
 271                 return ret;
 272
 273         dev = device_create(&intel_pmt_class, parent, MKDEV(0, 0), entry,
 274                             "%s%d", ns->name, entry->devid);
 275
 276         if (IS_ERR(dev)) {
 277                 dev_err(parent, "Could not create %s%d device node\n",
 278                         ns->name, entry->devid);
 279                 ret = PTR_ERR(dev);
 280                 goto fail_dev_create;
 281         }
 282
 283         entry->kobj = &dev->kobj;
 284
 285         if (ns->attr_grp) {
 286                 ret = sysfs_create_group(entry->kobj, ns->attr_grp);
 287                 if (ret)
 288                         goto fail_sysfs_create_group;
 289         }
 290
 291         /* if size is 0 assume no data buffer, so no file needed */
 292         if (!entry->size)
 293                 return 0;
 294
 295         res.start = entry->base_addr;
 296         res.end = res.start + entry->size - 1;
 297         res.flags = IORESOURCE_MEM;
 298
 299         entry->base = devm_ioremap_resource(dev, &res);
 300         if (IS_ERR(entry->base)) {
 301                 ret = PTR_ERR(entry->base);
 302                 goto fail_ioremap;
 303         }
 304
 305         sysfs_bin_attr_init(&entry->pmt_bin_attr);
 306         entry->pmt_bin_attr.attr.name = ns->name;
 307         entry->pmt_bin_attr.attr.mode = 0440;
 308         entry->pmt_bin_attr.mmap = intel_pmt_mmap;
 309         entry->pmt_bin_attr.read = intel_pmt_read;
 310         entry->pmt_bin_attr.size = entry->size;
 311
 312         ret = sysfs_create_bin_file(&dev->kobj, &entry->pmt_bin_attr);
 313         if (ret)
 314                 goto fail_ioremap;
 315
 316         if (ns->pmt_add_endpoint) {
 317                 ret = ns->pmt_add_endpoint(ivdev, entry);
 318                 if (ret)
 319                         goto fail_add_endpoint;
 320         }
 321
 322         return 0;
 323
 324 fail_add_endpoint:
 325         sysfs_remove_bin_file(entry->kobj, &entry->pmt_bin_attr);
 326 fail_ioremap:
 327         if (ns->attr_grp)
 328                 sysfs_remove_group(entry->kobj, ns->attr_grp);
 329 fail_sysfs_create_group:
 330         device_unregister(dev);
 331 fail_dev_create:
 332         xa_erase(ns->xa, entry->devid);
 333
 334         return ret;
 335 }
 336
 337 int intel_pmt_dev_create(struct intel_pmt_entry *entry, struct intel_pmt_namespace *ns,
 338                          struct intel_vsec_device *intel_vsec_dev, int idx)
 339 {
 340         struct device *dev = &intel_vsec_dev->auxdev.dev;
 341         struct resource *disc_res;
 342         int ret;
 343
 344         disc_res = &intel_vsec_dev->resource[idx];
 345
 346         entry->disc_table = devm_ioremap_resource(dev, disc_res);
 347         if (IS_ERR(entry->disc_table))
 348                 return PTR_ERR(entry->disc_table);
 349
 350         ret = ns->pmt_header_decode(entry, dev);
 351         if (ret)
 352                 return ret;
 353
 354         ret = intel_pmt_populate_entry(entry, intel_vsec_dev, disc_res);
 355         if (ret)
 356                 return ret;
 357
 358         return intel_pmt_dev_register(entry, ns, dev);
 359 }
 360 EXPORT_SYMBOL_NS_GPL(intel_pmt_dev_create, INTEL_PMT);
 361
 362 void intel_pmt_dev_destroy(struct intel_pmt_entry *entry,
 363                            struct intel_pmt_namespace *ns)
 364 {
 365         struct device *dev = kobj_to_dev(entry->kobj);
 366
 367         if (entry->size)
 368                 sysfs_remove_bin_file(entry->kobj, &entry->pmt_bin_attr);
 369
 370         if (ns->attr_grp)
 371                 sysfs_remove_group(entry->kobj, ns->attr_grp);
 372
 373         device_unregister(dev);
 374         xa_erase(ns->xa, entry->devid);
 375 }
 376 EXPORT_SYMBOL_NS_GPL(intel_pmt_dev_destroy, INTEL_PMT);
 377
 378 static int __init pmt_class_init(void)
 379 {
 380         return class_register(&intel_pmt_class);
 381 }
 382
 383 static void __exit pmt_class_exit(void)
 384 {
 385         class_unregister(&intel_pmt_class);
 386 }
 387
 388 module_init(pmt_class_init);
 389 module_exit(pmt_class_exit);
 390
 391 MODULE_AUTHOR("Alexander Duyck <[email protected]>");
 392 MODULE_DESCRIPTION("Intel PMT Class driver");
 393 MODULE_LICENSE("GPL v2");