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