1 // SPDX-License-Identifier: GPL-2.0
3 * Intel Platform Monitory Technology Telemetry driver
5 * Copyright (c) 2020, Intel Corporation.
8 * Author: "David E. Box" <david.e.box@linux.intel.com>
11 #include <linux/auxiliary_bus.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/pci.h>
15 #include <linux/slab.h>
16 #include <linux/uaccess.h>
17 #include <linux/overflow.h>
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)
29 /* Used by client hardware to identify a fixed telemetry entry*/
30 #define TELEM_CLIENT_FIXED_BLOCK_GUID 0x10000000
32 struct pmt_telem_priv {
34 struct intel_pmt_entry entry[];
37 static bool pmt_telem_region_overlaps(struct intel_pmt_entry *entry,
40 u32 guid = readl(entry->disc_table + TELEM_GUID_OFFSET);
42 if (guid != TELEM_CLIENT_FIXED_BLOCK_GUID)
45 return intel_pmt_is_early_client_hw(dev);
48 static int pmt_telem_header_decode(struct intel_pmt_entry *entry,
49 struct intel_pmt_header *header,
52 void __iomem *disc_table = entry->disc_table;
54 if (pmt_telem_region_overlaps(entry, dev))
57 header->access_type = TELEM_ACCESS(readl(disc_table));
58 header->guid = readl(disc_table + TELEM_GUID_OFFSET);
59 header->base_offset = readl(disc_table + TELEM_BASE_OFFSET);
61 /* Size is measured in DWORDS, but accessor returns bytes */
62 header->size = TELEM_SIZE(readl(disc_table));
65 * Some devices may expose non-functioning entries that are
66 * reserved for future use. They have zero size. Do not fail
67 * probe for these. Just ignore them.
69 if (header->size == 0)
75 static DEFINE_XARRAY_ALLOC(telem_array);
76 static struct intel_pmt_namespace pmt_telem_ns = {
79 .pmt_header_decode = pmt_telem_header_decode,
82 static void pmt_telem_remove(struct auxiliary_device *auxdev)
84 struct pmt_telem_priv *priv = auxiliary_get_drvdata(auxdev);
87 for (i = 0; i < priv->num_entries; i++)
88 intel_pmt_dev_destroy(&priv->entry[i], &pmt_telem_ns);
91 static int pmt_telem_probe(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id)
93 struct intel_vsec_device *intel_vsec_dev = auxdev_to_ivdev(auxdev);
94 struct pmt_telem_priv *priv;
98 size = struct_size(priv, entry, intel_vsec_dev->num_resources);
99 priv = devm_kzalloc(&auxdev->dev, size, GFP_KERNEL);
103 auxiliary_set_drvdata(auxdev, priv);
105 for (i = 0; i < intel_vsec_dev->num_resources; i++) {
106 struct intel_pmt_entry *entry = &priv->entry[priv->num_entries];
108 ret = intel_pmt_dev_create(entry, &pmt_telem_ns, intel_vsec_dev, i);
119 pmt_telem_remove(auxdev);
123 static const struct auxiliary_device_id pmt_telem_id_table[] = {
124 { .name = "intel_vsec.telemetry" },
127 MODULE_DEVICE_TABLE(auxiliary, pmt_telem_id_table);
129 static struct auxiliary_driver pmt_telem_aux_driver = {
130 .id_table = pmt_telem_id_table,
131 .remove = pmt_telem_remove,
132 .probe = pmt_telem_probe,
135 static int __init pmt_telem_init(void)
137 return auxiliary_driver_register(&pmt_telem_aux_driver);
139 module_init(pmt_telem_init);
141 static void __exit pmt_telem_exit(void)
143 auxiliary_driver_unregister(&pmt_telem_aux_driver);
144 xa_destroy(&telem_array);
146 module_exit(pmt_telem_exit);
148 MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
149 MODULE_DESCRIPTION("Intel PMT Telemetry driver");
150 MODULE_LICENSE("GPL v2");