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#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(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(disc_table + TELEM_GUID_OFFSET);
 80	header->base_offset = readl(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_pmt_entry *entry,
 97				  struct pci_dev *pdev)
 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 = pdev;
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
115	kref_init(&ep->kref);
116
117	return 0;
118}
119
120static DEFINE_XARRAY_ALLOC(telem_array);
121static struct intel_pmt_namespace pmt_telem_ns = {
122	.name = "telem",
123	.xa = &telem_array,
124	.pmt_header_decode = pmt_telem_header_decode,
125	.pmt_add_endpoint = pmt_telem_add_endpoint,
126};
127
128/* Called when all users unregister and the device is removed */
129static void pmt_telem_ep_release(struct kref *kref)
130{
131	struct telem_endpoint *ep;
132
133	ep = container_of(kref, struct telem_endpoint, kref);
134	kfree(ep);
135}
136
137unsigned long pmt_telem_get_next_endpoint(unsigned long start)
138{
139	struct intel_pmt_entry *entry;
140	unsigned long found_idx;
141
142	mutex_lock(&ep_lock);
143	xa_for_each_start(&telem_array, found_idx, entry, start) {
144		/*
145		 * Return first found index after start.
146		 * 0 is not valid id.
147		 */
148		if (found_idx > start)
149			break;
150	}
151	mutex_unlock(&ep_lock);
152
153	return found_idx == start ? 0 : found_idx;
154}
155EXPORT_SYMBOL_NS_GPL(pmt_telem_get_next_endpoint, INTEL_PMT_TELEMETRY);
156
157struct telem_endpoint *pmt_telem_register_endpoint(int devid)
158{
159	struct intel_pmt_entry *entry;
160	unsigned long index = devid;
161
162	mutex_lock(&ep_lock);
163	entry = xa_find(&telem_array, &index, index, XA_PRESENT);
164	if (!entry) {
165		mutex_unlock(&ep_lock);
166		return ERR_PTR(-ENXIO);
167	}
168
169	kref_get(&entry->ep->kref);
170	mutex_unlock(&ep_lock);
171
172	return entry->ep;
173}
174EXPORT_SYMBOL_NS_GPL(pmt_telem_register_endpoint, INTEL_PMT_TELEMETRY);
175
176void pmt_telem_unregister_endpoint(struct telem_endpoint *ep)
177{
178	kref_put(&ep->kref, pmt_telem_ep_release);
179}
180EXPORT_SYMBOL_NS_GPL(pmt_telem_unregister_endpoint, INTEL_PMT_TELEMETRY);
181
182int pmt_telem_get_endpoint_info(int devid, struct telem_endpoint_info *info)
183{
184	struct intel_pmt_entry *entry;
185	unsigned long index = devid;
186	int err = 0;
187
188	if (!info)
189		return -EINVAL;
190
191	mutex_lock(&ep_lock);
192	entry = xa_find(&telem_array, &index, index, XA_PRESENT);
193	if (!entry) {
194		err = -ENXIO;
195		goto unlock;
196	}
197
198	info->pdev = entry->ep->pcidev;
199	info->header = entry->ep->header;
200
201unlock:
202	mutex_unlock(&ep_lock);
203	return err;
204
205}
206EXPORT_SYMBOL_NS_GPL(pmt_telem_get_endpoint_info, INTEL_PMT_TELEMETRY);
207
208int pmt_telem_read(struct telem_endpoint *ep, u32 id, u64 *data, u32 count)
209{
210	u32 offset, size;
211
212	if (!ep->present)
213		return -ENODEV;
214
215	offset = SAMPLE_ID_OFFSET(id);
216	size = ep->header.size;
217
218	if (offset + NUM_BYTES_QWORD(count) > size)
219		return -EINVAL;
220
221	memcpy_fromio(data, ep->base + offset, NUM_BYTES_QWORD(count));
222
223	return ep->present ? 0 : -EPIPE;
224}
225EXPORT_SYMBOL_NS_GPL(pmt_telem_read, INTEL_PMT_TELEMETRY);
226
227int pmt_telem_read32(struct telem_endpoint *ep, u32 id, u32 *data, u32 count)
228{
229	u32 offset, size;
230
231	if (!ep->present)
232		return -ENODEV;
233
234	offset = SAMPLE_ID_OFFSET32(id);
235	size = ep->header.size;
236
237	if (offset + NUM_BYTES_DWORD(count) > size)
238		return -EINVAL;
239
240	memcpy_fromio(data, ep->base + offset, NUM_BYTES_DWORD(count));
241
242	return ep->present ? 0 : -EPIPE;
243}
244EXPORT_SYMBOL_NS_GPL(pmt_telem_read32, INTEL_PMT_TELEMETRY);
245
246struct telem_endpoint *
247pmt_telem_find_and_register_endpoint(struct pci_dev *pcidev, u32 guid, u16 pos)
248{
249	int devid = 0;
250	int inst = 0;
251	int err = 0;
252
253	while ((devid = pmt_telem_get_next_endpoint(devid))) {
254		struct telem_endpoint_info ep_info;
255
256		err = pmt_telem_get_endpoint_info(devid, &ep_info);
257		if (err)
258			return ERR_PTR(err);
259
260		if (ep_info.header.guid == guid && ep_info.pdev == pcidev) {
261			if (inst == pos)
262				return pmt_telem_register_endpoint(devid);
263			++inst;
264		}
265	}
266
267	return ERR_PTR(-ENXIO);
268}
269EXPORT_SYMBOL_NS_GPL(pmt_telem_find_and_register_endpoint, INTEL_PMT_TELEMETRY);
270
271static void pmt_telem_remove(struct auxiliary_device *auxdev)
272{
273	struct pmt_telem_priv *priv = auxiliary_get_drvdata(auxdev);
274	int i;
275
276	mutex_lock(&ep_lock);
277	for (i = 0; i < priv->num_entries; i++) {
278		struct intel_pmt_entry *entry = &priv->entry[i];
279
280		kref_put(&entry->ep->kref, pmt_telem_ep_release);
281		intel_pmt_dev_destroy(entry, &pmt_telem_ns);
282	}
283	mutex_unlock(&ep_lock);
284};
285
286static int pmt_telem_probe(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id)
287{
288	struct intel_vsec_device *intel_vsec_dev = auxdev_to_ivdev(auxdev);
289	struct pmt_telem_priv *priv;
290	size_t size;
291	int i, ret;
292
293	size = struct_size(priv, entry, intel_vsec_dev->num_resources);
294	priv = devm_kzalloc(&auxdev->dev, size, GFP_KERNEL);
295	if (!priv)
296		return -ENOMEM;
297
298	auxiliary_set_drvdata(auxdev, priv);
299
300	for (i = 0; i < intel_vsec_dev->num_resources; i++) {
301		struct intel_pmt_entry *entry = &priv->entry[priv->num_entries];
302
303		mutex_lock(&ep_lock);
304		ret = intel_pmt_dev_create(entry, &pmt_telem_ns, intel_vsec_dev, i);
305		mutex_unlock(&ep_lock);
306		if (ret < 0)
307			goto abort_probe;
308		if (ret)
309			continue;
310
311		priv->num_entries++;
312	}
313
314	return 0;
315abort_probe:
316	pmt_telem_remove(auxdev);
317	return ret;
318}
319
320static const struct auxiliary_device_id pmt_telem_id_table[] = {
321	{ .name = "intel_vsec.telemetry" },
322	{}
323};
324MODULE_DEVICE_TABLE(auxiliary, pmt_telem_id_table);
325
326static struct auxiliary_driver pmt_telem_aux_driver = {
327	.id_table	= pmt_telem_id_table,
328	.remove		= pmt_telem_remove,
329	.probe		= pmt_telem_probe,
330};
331
332static int __init pmt_telem_init(void)
333{
334	return auxiliary_driver_register(&pmt_telem_aux_driver);
335}
336module_init(pmt_telem_init);
337
338static void __exit pmt_telem_exit(void)
339{
340	auxiliary_driver_unregister(&pmt_telem_aux_driver);
341	xa_destroy(&telem_array);
342}
343module_exit(pmt_telem_exit);
344
345MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
346MODULE_DESCRIPTION("Intel PMT Telemetry driver");
347MODULE_LICENSE("GPL v2");
348MODULE_IMPORT_NS(INTEL_PMT);