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/intel_vsec.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/pci.h>
16#include <linux/slab.h>
17#include <linux/uaccess.h>
18#include <linux/overflow.h>
19
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#define NUM_BYTES_QWORD(v) ((v) << 3)
34#define SAMPLE_ID_OFFSET(v) ((v) << 3)
35
36#define NUM_BYTES_DWORD(v) ((v) << 2)
37#define SAMPLE_ID_OFFSET32(v) ((v) << 2)
38
39/* Protects access to the xarray of telemetry endpoint handles */
40static DEFINE_MUTEX(ep_lock);
41
42enum telem_type {
43 TELEM_TYPE_PUNIT = 0,
44 TELEM_TYPE_CRASHLOG,
45 TELEM_TYPE_PUNIT_FIXED,
46};
47
48struct pmt_telem_priv {
49 int num_entries;
50 struct intel_pmt_entry entry[];
51};
52
53static bool pmt_telem_region_overlaps(struct intel_pmt_entry *entry,
54 struct device *dev)
55{
56 u32 guid = readl(addr: entry->disc_table + TELEM_GUID_OFFSET);
57
58 if (intel_pmt_is_early_client_hw(dev)) {
59 u32 type = TELEM_TYPE(readl(entry->disc_table));
60
61 if ((type == TELEM_TYPE_PUNIT_FIXED) ||
62 (guid == TELEM_CLIENT_FIXED_BLOCK_GUID))
63 return true;
64 }
65
66 return false;
67}
68
69static int pmt_telem_header_decode(struct intel_pmt_entry *entry,
70 struct device *dev)
71{
72 void __iomem *disc_table = entry->disc_table;
73 struct intel_pmt_header *header = &entry->header;
74
75 if (pmt_telem_region_overlaps(entry, dev))
76 return 1;
77
78 header->access_type = TELEM_ACCESS(readl(disc_table));
79 header->guid = readl(addr: disc_table + TELEM_GUID_OFFSET);
80 header->base_offset = readl(addr: disc_table + TELEM_BASE_OFFSET);
81
82 /* Size is measured in DWORDS, but accessor returns bytes */
83 header->size = TELEM_SIZE(readl(disc_table));
84
85 /*
86 * Some devices may expose non-functioning entries that are
87 * reserved for future use. They have zero size. Do not fail
88 * probe for these. Just ignore them.
89 */
90 if (header->size == 0 || header->access_type == 0xF)
91 return 1;
92
93 return 0;
94}
95
96static int pmt_telem_add_endpoint(struct intel_vsec_device *ivdev,
97 struct intel_pmt_entry *entry)
98{
99 struct telem_endpoint *ep;
100
101 /* Endpoint lifetimes are managed by kref, not devres */
102 entry->ep = kzalloc(sizeof(*(entry->ep)), GFP_KERNEL);
103 if (!entry->ep)
104 return -ENOMEM;
105
106 ep = entry->ep;
107 ep->pcidev = ivdev->pcidev;
108 ep->header.access_type = entry->header.access_type;
109 ep->header.guid = entry->header.guid;
110 ep->header.base_offset = entry->header.base_offset;
111 ep->header.size = entry->header.size;
112 ep->base = entry->base;
113 ep->present = true;
114 ep->cb = ivdev->priv_data;
115
116 kref_init(kref: &ep->kref);
117
118 return 0;
119}
120
121static DEFINE_XARRAY_ALLOC(telem_array);
122static struct intel_pmt_namespace pmt_telem_ns = {
123 .name = "telem",
124 .xa = &telem_array,
125 .pmt_header_decode = pmt_telem_header_decode,
126 .pmt_add_endpoint = pmt_telem_add_endpoint,
127};
128
129/* Called when all users unregister and the device is removed */
130static void pmt_telem_ep_release(struct kref *kref)
131{
132 struct telem_endpoint *ep;
133
134 ep = container_of(kref, struct telem_endpoint, kref);
135 kfree(objp: ep);
136}
137
138unsigned long pmt_telem_get_next_endpoint(unsigned long start)
139{
140 struct intel_pmt_entry *entry;
141 unsigned long found_idx;
142
143 mutex_lock(&ep_lock);
144 xa_for_each_start(&telem_array, found_idx, entry, start) {
145 /*
146 * Return first found index after start.
147 * 0 is not valid id.
148 */
149 if (found_idx > start)
150 break;
151 }
152 mutex_unlock(lock: &ep_lock);
153
154 return found_idx == start ? 0 : found_idx;
155}
156EXPORT_SYMBOL_NS_GPL(pmt_telem_get_next_endpoint, "INTEL_PMT_TELEMETRY");
157
158struct telem_endpoint *pmt_telem_register_endpoint(int devid)
159{
160 struct intel_pmt_entry *entry;
161 unsigned long index = devid;
162
163 mutex_lock(&ep_lock);
164 entry = xa_find(xa: &telem_array, index: &index, max: index, XA_PRESENT);
165 if (!entry) {
166 mutex_unlock(lock: &ep_lock);
167 return ERR_PTR(error: -ENXIO);
168 }
169
170 kref_get(kref: &entry->ep->kref);
171 mutex_unlock(lock: &ep_lock);
172
173 return entry->ep;
174}
175EXPORT_SYMBOL_NS_GPL(pmt_telem_register_endpoint, "INTEL_PMT_TELEMETRY");
176
177void pmt_telem_unregister_endpoint(struct telem_endpoint *ep)
178{
179 kref_put(kref: &ep->kref, release: pmt_telem_ep_release);
180}
181EXPORT_SYMBOL_NS_GPL(pmt_telem_unregister_endpoint, "INTEL_PMT_TELEMETRY");
182
183int pmt_telem_get_endpoint_info(int devid, struct telem_endpoint_info *info)
184{
185 struct intel_pmt_entry *entry;
186 unsigned long index = devid;
187 int err = 0;
188
189 if (!info)
190 return -EINVAL;
191
192 mutex_lock(&ep_lock);
193 entry = xa_find(xa: &telem_array, index: &index, max: index, XA_PRESENT);
194 if (!entry) {
195 err = -ENXIO;
196 goto unlock;
197 }
198
199 info->pdev = entry->ep->pcidev;
200 info->header = entry->ep->header;
201
202unlock:
203 mutex_unlock(lock: &ep_lock);
204 return err;
205
206}
207EXPORT_SYMBOL_NS_GPL(pmt_telem_get_endpoint_info, "INTEL_PMT_TELEMETRY");
208
209int pmt_telem_read(struct telem_endpoint *ep, u32 id, u64 *data, u32 count)
210{
211 u32 offset, size;
212
213 if (!ep->present)
214 return -ENODEV;
215
216 offset = SAMPLE_ID_OFFSET(id);
217 size = ep->header.size;
218
219 if (offset + NUM_BYTES_QWORD(count) > size)
220 return -EINVAL;
221
222 pmt_telem_read_mmio(pdev: ep->pcidev, cb: ep->cb, guid: ep->header.guid, buf: data, addr: ep->base, off: offset,
223 NUM_BYTES_QWORD(count));
224
225 return ep->present ? 0 : -EPIPE;
226}
227EXPORT_SYMBOL_NS_GPL(pmt_telem_read, "INTEL_PMT_TELEMETRY");
228
229int pmt_telem_read32(struct telem_endpoint *ep, u32 id, u32 *data, u32 count)
230{
231 u32 offset, size;
232
233 if (!ep->present)
234 return -ENODEV;
235
236 offset = SAMPLE_ID_OFFSET32(id);
237 size = ep->header.size;
238
239 if (offset + NUM_BYTES_DWORD(count) > size)
240 return -EINVAL;
241
242 memcpy_fromio(data, ep->base + offset, NUM_BYTES_DWORD(count));
243
244 return ep->present ? 0 : -EPIPE;
245}
246EXPORT_SYMBOL_NS_GPL(pmt_telem_read32, "INTEL_PMT_TELEMETRY");
247
248struct telem_endpoint *
249pmt_telem_find_and_register_endpoint(struct pci_dev *pcidev, u32 guid, u16 pos)
250{
251 int devid = 0;
252 int inst = 0;
253 int err = 0;
254
255 while ((devid = pmt_telem_get_next_endpoint(devid))) {
256 struct telem_endpoint_info ep_info;
257
258 err = pmt_telem_get_endpoint_info(devid, &ep_info);
259 if (err)
260 return ERR_PTR(error: err);
261
262 if (ep_info.header.guid == guid && ep_info.pdev == pcidev) {
263 if (inst == pos)
264 return pmt_telem_register_endpoint(devid);
265 ++inst;
266 }
267 }
268
269 return ERR_PTR(error: -ENXIO);
270}
271EXPORT_SYMBOL_NS_GPL(pmt_telem_find_and_register_endpoint, "INTEL_PMT_TELEMETRY");
272
273static void pmt_telem_remove(struct auxiliary_device *auxdev)
274{
275 struct pmt_telem_priv *priv = auxiliary_get_drvdata(auxdev);
276 int i;
277
278 mutex_lock(&ep_lock);
279 for (i = 0; i < priv->num_entries; i++) {
280 struct intel_pmt_entry *entry = &priv->entry[i];
281
282 kref_put(kref: &entry->ep->kref, release: pmt_telem_ep_release);
283 intel_pmt_dev_destroy(entry, ns: &pmt_telem_ns);
284 }
285 mutex_unlock(lock: &ep_lock);
286};
287
288static int pmt_telem_probe(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id)
289{
290 struct intel_vsec_device *intel_vsec_dev = auxdev_to_ivdev(auxdev);
291 struct pmt_telem_priv *priv;
292 size_t size;
293 int i, ret;
294
295 size = struct_size(priv, entry, intel_vsec_dev->num_resources);
296 priv = devm_kzalloc(dev: &auxdev->dev, size, GFP_KERNEL);
297 if (!priv)
298 return -ENOMEM;
299
300 auxiliary_set_drvdata(auxdev, data: priv);
301
302 for (i = 0; i < intel_vsec_dev->num_resources; i++) {
303 struct intel_pmt_entry *entry = &priv->entry[priv->num_entries];
304
305 mutex_lock(&ep_lock);
306 ret = intel_pmt_dev_create(entry, ns: &pmt_telem_ns, dev: intel_vsec_dev, idx: i);
307 mutex_unlock(lock: &ep_lock);
308 if (ret < 0)
309 goto abort_probe;
310 if (ret)
311 continue;
312
313 priv->num_entries++;
314 }
315
316 return 0;
317abort_probe:
318 pmt_telem_remove(auxdev);
319 return ret;
320}
321
322static const struct auxiliary_device_id pmt_telem_id_table[] = {
323 { .name = "intel_vsec.telemetry" },
324 {}
325};
326MODULE_DEVICE_TABLE(auxiliary, pmt_telem_id_table);
327
328static struct auxiliary_driver pmt_telem_aux_driver = {
329 .id_table = pmt_telem_id_table,
330 .remove = pmt_telem_remove,
331 .probe = pmt_telem_probe,
332};
333
334static int __init pmt_telem_init(void)
335{
336 return auxiliary_driver_register(&pmt_telem_aux_driver);
337}
338module_init(pmt_telem_init);
339
340static void __exit pmt_telem_exit(void)
341{
342 auxiliary_driver_unregister(auxdrv: &pmt_telem_aux_driver);
343 xa_destroy(&telem_array);
344}
345module_exit(pmt_telem_exit);
346
347MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
348MODULE_DESCRIPTION("Intel PMT Telemetry driver");
349MODULE_LICENSE("GPL v2");
350MODULE_IMPORT_NS("INTEL_PMT");
351

source code of linux/drivers/platform/x86/intel/pmt/telemetry.c