LXR linux/drivers/platform/x86/intel_pmt

   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/kernel.h>
  12#include <linux/module.h>
  13#include <linux/pci.h>
  14#include <linux/slab.h>
  15#include <linux/uaccess.h>
  16#include <linux/overflow.h>
  17
  18#include "intel_pmt_class.h"
  19
  20#define TELEM_DEV_NAME          "pmt_telemetry"
  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/* size is in bytes */
  27#define TELEM_SIZE(v)           (((v) & GENMASK(27, 12)) >> 10)
  28
  29/* Used by client hardware to identify a fixed telemetry entry*/
  30#define TELEM_CLIENT_FIXED_BLOCK_GUID   0x10000000
  31
  32struct pmt_telem_priv {
  33        int                             num_entries;
  34        struct intel_pmt_entry          entry[];
  35};
  36
  37/*
  38 * Early implementations of PMT on client platforms have some
  39 * differences from the server platforms (which use the Out Of Band
  40 * Management Services Module OOBMSM). This list tracks those
  41 * platforms as needed to handle those differences. Newer client
  42 * platforms are expected to be fully compatible with server.
  43 */
  44static const struct pci_device_id pmt_telem_early_client_pci_ids[] = {
  45        { PCI_VDEVICE(INTEL, 0x9a0d) }, /* TGL */
  46        { PCI_VDEVICE(INTEL, 0x467d) }, /* ADL */
  47        { }
  48};
  49
  50static bool intel_pmt_is_early_client_hw(struct device *dev)
  51{
  52        struct pci_dev *parent = to_pci_dev(dev->parent);
  53
  54        return !!pci_match_id(pmt_telem_early_client_pci_ids, parent);
  55}
  56
  57static bool pmt_telem_region_overlaps(struct intel_pmt_entry *entry,
  58                                      struct device *dev)
  59{
  60        u32 guid = readl(entry->disc_table + TELEM_GUID_OFFSET);
  61
  62        if (guid != TELEM_CLIENT_FIXED_BLOCK_GUID)
  63                return false;
  64
  65        return intel_pmt_is_early_client_hw(dev);
  66}
  67
  68static int pmt_telem_header_decode(struct intel_pmt_entry *entry,
  69                                   struct intel_pmt_header *header,
  70                                   struct device *dev)
  71{
  72        void __iomem *disc_table = entry->disc_table;
  73
  74        if (pmt_telem_region_overlaps(entry, dev))
  75                return 1;
  76
  77        header->access_type = TELEM_ACCESS(readl(disc_table));
  78        header->guid = readl(disc_table + TELEM_GUID_OFFSET);
  79        header->base_offset = readl(disc_table + TELEM_BASE_OFFSET);
  80
  81        /* Size is measured in DWORDS, but accessor returns bytes */
  82        header->size = TELEM_SIZE(readl(disc_table));
  83
  84        return 0;
  85}
  86
  87static DEFINE_XARRAY_ALLOC(telem_array);
  88static struct intel_pmt_namespace pmt_telem_ns = {
  89        .name = "telem",
  90        .xa = &telem_array,
  91        .pmt_header_decode = pmt_telem_header_decode,
  92};
  93
  94static int pmt_telem_remove(struct platform_device *pdev)
  95{
  96        struct pmt_telem_priv *priv = platform_get_drvdata(pdev);
  97        int i;
  98
  99        for (i = 0; i < priv->num_entries; i++)
 100                intel_pmt_dev_destroy(&priv->entry[i], &pmt_telem_ns);
 101
 102        return 0;
 103}
 104
 105static int pmt_telem_probe(struct platform_device *pdev)
 106{
 107        struct pmt_telem_priv *priv;
 108        size_t size;
 109        int i, ret;
 110
 111        size = struct_size(priv, entry, pdev->num_resources);
 112        priv = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
 113        if (!priv)
 114                return -ENOMEM;
 115
 116        platform_set_drvdata(pdev, priv);
 117
 118        for (i = 0; i < pdev->num_resources; i++) {
 119                struct intel_pmt_entry *entry = &priv->entry[i];
 120
 121                ret = intel_pmt_dev_create(entry, &pmt_telem_ns, pdev, i);
 122                if (ret < 0)
 123                        goto abort_probe;
 124                if (ret)
 125                        continue;
 126
 127                priv->num_entries++;
 128        }
 129
 130        return 0;
 131abort_probe:
 132        pmt_telem_remove(pdev);
 133        return ret;
 134}
 135
 136static struct platform_driver pmt_telem_driver = {
 137        .driver = {
 138                .name   = TELEM_DEV_NAME,
 139        },
 140        .remove = pmt_telem_remove,
 141        .probe  = pmt_telem_probe,
 142};
 143
 144static int __init pmt_telem_init(void)
 145{
 146        return platform_driver_register(&pmt_telem_driver);
 147}
 148module_init(pmt_telem_init);
 149
 150static void __exit pmt_telem_exit(void)
 151{
 152        platform_driver_unregister(&pmt_telem_driver);
 153        xa_destroy(&telem_array);
 154}
 155module_exit(pmt_telem_exit);
 156
 157MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
 158MODULE_DESCRIPTION("Intel PMT Telemetry driver");
 159MODULE_ALIAS("platform:" TELEM_DEV_NAME);
 160MODULE_LICENSE("GPL v2");
 161