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 #define TELEM_TYPE(v) (((v) & GENMASK(7, 4)) >> 4) 27 /* size is in bytes */ 28 #define TELEM_SIZE(v) (((v) & GENMASK(27, 12)) >> 10) 29 30 /* Used by client hardware to identify a fixed telemetry entry*/ 31 #define TELEM_CLIENT_FIXED_BLOCK_GUID 0x10000000 32 33 enum telem_type { 34 TELEM_TYPE_PUNIT = 0, 35 TELEM_TYPE_CRASHLOG, 36 TELEM_TYPE_PUNIT_FIXED, 37 }; 38 39 struct pmt_telem_priv { 40 int num_entries; 41 struct intel_pmt_entry entry[]; 42 }; 43 44 static bool pmt_telem_region_overlaps(struct intel_pmt_entry *entry, 45 struct device *dev) 46 { 47 u32 guid = readl(entry->disc_table + TELEM_GUID_OFFSET); 48 49 if (intel_pmt_is_early_client_hw(dev)) { 50 u32 type = TELEM_TYPE(readl(entry->disc_table)); 51 52 if ((type == TELEM_TYPE_PUNIT_FIXED) || 53 (guid == TELEM_CLIENT_FIXED_BLOCK_GUID)) 54 return true; 55 } 56 57 return false; 58 } 59 60 static int pmt_telem_header_decode(struct intel_pmt_entry *entry, 61 struct intel_pmt_header *header, 62 struct device *dev) 63 { 64 void __iomem *disc_table = entry->disc_table; 65 66 if (pmt_telem_region_overlaps(entry, dev)) 67 return 1; 68 69 header->access_type = TELEM_ACCESS(readl(disc_table)); 70 header->guid = readl(disc_table + TELEM_GUID_OFFSET); 71 header->base_offset = readl(disc_table + TELEM_BASE_OFFSET); 72 73 /* Size is measured in DWORDS, but accessor returns bytes */ 74 header->size = TELEM_SIZE(readl(disc_table)); 75 76 /* 77 * Some devices may expose non-functioning entries that are 78 * reserved for future use. They have zero size. Do not fail 79 * probe for these. Just ignore them. 80 */ 81 if (header->size == 0 || header->access_type == 0xF) 82 return 1; 83 84 return 0; 85 } 86 87 static DEFINE_XARRAY_ALLOC(telem_array); 88 static struct intel_pmt_namespace pmt_telem_ns = { 89 .name = "telem", 90 .xa = &telem_array, 91 .pmt_header_decode = pmt_telem_header_decode, 92 }; 93 94 static void pmt_telem_remove(struct auxiliary_device *auxdev) 95 { 96 struct pmt_telem_priv *priv = auxiliary_get_drvdata(auxdev); 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 } 102 103 static int pmt_telem_probe(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id) 104 { 105 struct intel_vsec_device *intel_vsec_dev = auxdev_to_ivdev(auxdev); 106 struct pmt_telem_priv *priv; 107 size_t size; 108 int i, ret; 109 110 size = struct_size(priv, entry, intel_vsec_dev->num_resources); 111 priv = devm_kzalloc(&auxdev->dev, size, GFP_KERNEL); 112 if (!priv) 113 return -ENOMEM; 114 115 auxiliary_set_drvdata(auxdev, priv); 116 117 for (i = 0; i < intel_vsec_dev->num_resources; i++) { 118 struct intel_pmt_entry *entry = &priv->entry[priv->num_entries]; 119 120 ret = intel_pmt_dev_create(entry, &pmt_telem_ns, intel_vsec_dev, i); 121 if (ret < 0) 122 goto abort_probe; 123 if (ret) 124 continue; 125 126 priv->num_entries++; 127 } 128 129 return 0; 130 abort_probe: 131 pmt_telem_remove(auxdev); 132 return ret; 133 } 134 135 static const struct auxiliary_device_id pmt_telem_id_table[] = { 136 { .name = "intel_vsec.telemetry" }, 137 {} 138 }; 139 MODULE_DEVICE_TABLE(auxiliary, pmt_telem_id_table); 140 141 static struct auxiliary_driver pmt_telem_aux_driver = { 142 .id_table = pmt_telem_id_table, 143 .remove = pmt_telem_remove, 144 .probe = pmt_telem_probe, 145 }; 146 147 static int __init pmt_telem_init(void) 148 { 149 return auxiliary_driver_register(&pmt_telem_aux_driver); 150 } 151 module_init(pmt_telem_init); 152 153 static void __exit pmt_telem_exit(void) 154 { 155 auxiliary_driver_unregister(&pmt_telem_aux_driver); 156 xa_destroy(&telem_array); 157 } 158 module_exit(pmt_telem_exit); 159 160 MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>"); 161 MODULE_DESCRIPTION("Intel PMT Telemetry driver"); 162 MODULE_LICENSE("GPL v2"); 163 MODULE_IMPORT_NS(INTEL_PMT); 164