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/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> 18 19 #include "../vsec.h" 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 /* 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 32 struct pmt_telem_priv { 33 int num_entries; 34 struct intel_pmt_entry entry[]; 35 }; 36 37 static bool pmt_telem_region_overlaps(struct intel_pmt_entry *entry, 38 struct device *dev) 39 { 40 u32 guid = readl(entry->disc_table + TELEM_GUID_OFFSET); 41 42 if (guid != TELEM_CLIENT_FIXED_BLOCK_GUID) 43 return false; 44 45 return intel_pmt_is_early_client_hw(dev); 46 } 47 48 static int pmt_telem_header_decode(struct intel_pmt_entry *entry, 49 struct intel_pmt_header *header, 50 struct device *dev) 51 { 52 void __iomem *disc_table = entry->disc_table; 53 54 if (pmt_telem_region_overlaps(entry, dev)) 55 return 1; 56 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); 60 61 /* Size is measured in DWORDS, but accessor returns bytes */ 62 header->size = TELEM_SIZE(readl(disc_table)); 63 64 /* 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. 68 */ 69 if (header->size == 0) 70 return 1; 71 72 return 0; 73 } 74 75 static DEFINE_XARRAY_ALLOC(telem_array); 76 static struct intel_pmt_namespace pmt_telem_ns = { 77 .name = "telem", 78 .xa = &telem_array, 79 .pmt_header_decode = pmt_telem_header_decode, 80 }; 81 82 static void pmt_telem_remove(struct auxiliary_device *auxdev) 83 { 84 struct pmt_telem_priv *priv = auxiliary_get_drvdata(auxdev); 85 int i; 86 87 for (i = 0; i < priv->num_entries; i++) 88 intel_pmt_dev_destroy(&priv->entry[i], &pmt_telem_ns); 89 } 90 91 static int pmt_telem_probe(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id) 92 { 93 struct intel_vsec_device *intel_vsec_dev = auxdev_to_ivdev(auxdev); 94 struct pmt_telem_priv *priv; 95 size_t size; 96 int i, ret; 97 98 size = struct_size(priv, entry, intel_vsec_dev->num_resources); 99 priv = devm_kzalloc(&auxdev->dev, size, GFP_KERNEL); 100 if (!priv) 101 return -ENOMEM; 102 103 auxiliary_set_drvdata(auxdev, priv); 104 105 for (i = 0; i < intel_vsec_dev->num_resources; i++) { 106 struct intel_pmt_entry *entry = &priv->entry[i]; 107 108 ret = intel_pmt_dev_create(entry, &pmt_telem_ns, intel_vsec_dev, i); 109 if (ret < 0) 110 goto abort_probe; 111 if (ret) 112 continue; 113 114 priv->num_entries++; 115 } 116 117 return 0; 118 abort_probe: 119 pmt_telem_remove(auxdev); 120 return ret; 121 } 122 123 static const struct auxiliary_device_id pmt_telem_id_table[] = { 124 { .name = "intel_vsec.telemetry" }, 125 {} 126 }; 127 MODULE_DEVICE_TABLE(auxiliary, pmt_telem_id_table); 128 129 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, 133 }; 134 135 static int __init pmt_telem_init(void) 136 { 137 return auxiliary_driver_register(&pmt_telem_aux_driver); 138 } 139 module_init(pmt_telem_init); 140 141 static void __exit pmt_telem_exit(void) 142 { 143 auxiliary_driver_unregister(&pmt_telem_aux_driver); 144 xa_destroy(&telem_array); 145 } 146 module_exit(pmt_telem_exit); 147 148 MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>"); 149 MODULE_DESCRIPTION("Intel PMT Telemetry driver"); 150 MODULE_LICENSE("GPL v2"); 151