1// SPDX-License-Identifier: GPL-2.0
2/*
3 * ACPI Platform Firmware Runtime Telemetry driver
4 *
5 * Copyright (C) 2021 Intel Corporation
6 * Author: Chen Yu <yu.c.chen@intel.com>
7 *
8 * This driver allows user space to fetch telemetry data from the
9 * firmware with the help of the Platform Firmware Runtime Telemetry
10 * interface.
11 */
12#include <linux/acpi.h>
13#include <linux/device.h>
14#include <linux/err.h>
15#include <linux/errno.h>
16#include <linux/file.h>
17#include <linux/fs.h>
18#include <linux/miscdevice.h>
19#include <linux/module.h>
20#include <linux/mm.h>
21#include <linux/platform_device.h>
22#include <linux/string.h>
23#include <linux/uaccess.h>
24#include <linux/uio.h>
25#include <linux/uuid.h>
26
27#include <uapi/linux/pfrut.h>
28
29#define PFRT_LOG_EXEC_IDX	0
30#define PFRT_LOG_HISTORY_IDX	1
31
32#define PFRT_LOG_ERR		0
33#define PFRT_LOG_WARN	1
34#define PFRT_LOG_INFO	2
35#define PFRT_LOG_VERB	4
36
37#define PFRT_FUNC_SET_LEV		1
38#define PFRT_FUNC_GET_LEV		2
39#define PFRT_FUNC_GET_DATA		3
40
41#define PFRT_REVID_1		1
42#define PFRT_REVID_2		2
43#define PFRT_DEFAULT_REV_ID	PFRT_REVID_1
44
45enum log_index {
46	LOG_STATUS_IDX = 0,
47	LOG_EXT_STATUS_IDX = 1,
48	LOG_MAX_SZ_IDX = 2,
49	LOG_CHUNK1_LO_IDX = 3,
50	LOG_CHUNK1_HI_IDX = 4,
51	LOG_CHUNK1_SZ_IDX = 5,
52	LOG_CHUNK2_LO_IDX = 6,
53	LOG_CHUNK2_HI_IDX = 7,
54	LOG_CHUNK2_SZ_IDX = 8,
55	LOG_ROLLOVER_CNT_IDX = 9,
56	LOG_RESET_CNT_IDX = 10,
57	LOG_NR_IDX
58};
59
60struct pfrt_log_device {
61	int index;
62	struct pfrt_log_info info;
63	struct device *parent_dev;
64	struct miscdevice miscdev;
65};
66
67/* pfrt_guid is the parameter for _DSM method */
68static const guid_t pfrt_log_guid =
69	GUID_INIT(0x75191659, 0x8178, 0x4D9D, 0xB8, 0x8F, 0xAC, 0x5E,
70		  0x5E, 0x93, 0xE8, 0xBF);
71
72static DEFINE_IDA(pfrt_log_ida);
73
74static inline struct pfrt_log_device *to_pfrt_log_dev(struct file *file)
75{
76	return container_of(file->private_data, struct pfrt_log_device, miscdev);
77}
78
79static int get_pfrt_log_data_info(struct pfrt_log_data_info *data_info,
80				  struct pfrt_log_device *pfrt_log_dev)
81{
82	acpi_handle handle = ACPI_HANDLE(pfrt_log_dev->parent_dev);
83	union acpi_object *out_obj, in_obj, in_buf;
84	int ret = -EBUSY;
85
86	memset(data_info, 0, sizeof(*data_info));
87	memset(&in_obj, 0, sizeof(in_obj));
88	memset(&in_buf, 0, sizeof(in_buf));
89	in_obj.type = ACPI_TYPE_PACKAGE;
90	in_obj.package.count = 1;
91	in_obj.package.elements = &in_buf;
92	in_buf.type = ACPI_TYPE_INTEGER;
93	in_buf.integer.value = pfrt_log_dev->info.log_type;
94
95	out_obj = acpi_evaluate_dsm_typed(handle, &pfrt_log_guid,
96					  pfrt_log_dev->info.log_revid, PFRT_FUNC_GET_DATA,
97					  &in_obj, ACPI_TYPE_PACKAGE);
98	if (!out_obj)
99		return -EINVAL;
100
101	if (out_obj->package.count < LOG_NR_IDX ||
102	    out_obj->package.elements[LOG_STATUS_IDX].type != ACPI_TYPE_INTEGER ||
103	    out_obj->package.elements[LOG_EXT_STATUS_IDX].type != ACPI_TYPE_INTEGER ||
104	    out_obj->package.elements[LOG_MAX_SZ_IDX].type != ACPI_TYPE_INTEGER ||
105	    out_obj->package.elements[LOG_CHUNK1_LO_IDX].type != ACPI_TYPE_INTEGER ||
106	    out_obj->package.elements[LOG_CHUNK1_HI_IDX].type != ACPI_TYPE_INTEGER ||
107	    out_obj->package.elements[LOG_CHUNK1_SZ_IDX].type != ACPI_TYPE_INTEGER ||
108	    out_obj->package.elements[LOG_CHUNK2_LO_IDX].type != ACPI_TYPE_INTEGER ||
109	    out_obj->package.elements[LOG_CHUNK2_HI_IDX].type != ACPI_TYPE_INTEGER ||
110	    out_obj->package.elements[LOG_CHUNK2_SZ_IDX].type != ACPI_TYPE_INTEGER ||
111	    out_obj->package.elements[LOG_ROLLOVER_CNT_IDX].type != ACPI_TYPE_INTEGER ||
112	    out_obj->package.elements[LOG_RESET_CNT_IDX].type != ACPI_TYPE_INTEGER)
113		goto free_acpi_buffer;
114
115	data_info->status = out_obj->package.elements[LOG_STATUS_IDX].integer.value;
116	data_info->ext_status =
117		out_obj->package.elements[LOG_EXT_STATUS_IDX].integer.value;
118	if (data_info->status != DSM_SUCCEED) {
119		dev_dbg(pfrt_log_dev->parent_dev, "Error Status:%d\n", data_info->status);
120		dev_dbg(pfrt_log_dev->parent_dev, "Error Extend Status:%d\n",
121			data_info->ext_status);
122		goto free_acpi_buffer;
123	}
124
125	data_info->max_data_size =
126		out_obj->package.elements[LOG_MAX_SZ_IDX].integer.value;
127	data_info->chunk1_addr_lo =
128		out_obj->package.elements[LOG_CHUNK1_LO_IDX].integer.value;
129	data_info->chunk1_addr_hi =
130		out_obj->package.elements[LOG_CHUNK1_HI_IDX].integer.value;
131	data_info->chunk1_size =
132		out_obj->package.elements[LOG_CHUNK1_SZ_IDX].integer.value;
133	data_info->chunk2_addr_lo =
134		out_obj->package.elements[LOG_CHUNK2_LO_IDX].integer.value;
135	data_info->chunk2_addr_hi =
136		out_obj->package.elements[LOG_CHUNK2_HI_IDX].integer.value;
137	data_info->chunk2_size =
138		out_obj->package.elements[LOG_CHUNK2_SZ_IDX].integer.value;
139	data_info->rollover_cnt =
140		out_obj->package.elements[LOG_ROLLOVER_CNT_IDX].integer.value;
141	data_info->reset_cnt =
142		out_obj->package.elements[LOG_RESET_CNT_IDX].integer.value;
143
144	ret = 0;
145
146free_acpi_buffer:
147	ACPI_FREE(out_obj);
148
149	return ret;
150}
151
152static int set_pfrt_log_level(int level, struct pfrt_log_device *pfrt_log_dev)
153{
154	acpi_handle handle = ACPI_HANDLE(pfrt_log_dev->parent_dev);
155	union acpi_object *out_obj, *obj, in_obj, in_buf;
156	enum pfru_dsm_status status, ext_status;
157	int ret = 0;
158
159	memset(&in_obj, 0, sizeof(in_obj));
160	memset(&in_buf, 0, sizeof(in_buf));
161	in_obj.type = ACPI_TYPE_PACKAGE;
162	in_obj.package.count = 1;
163	in_obj.package.elements = &in_buf;
164	in_buf.type = ACPI_TYPE_INTEGER;
165	in_buf.integer.value = level;
166
167	out_obj = acpi_evaluate_dsm_typed(handle, &pfrt_log_guid,
168					  pfrt_log_dev->info.log_revid, PFRT_FUNC_SET_LEV,
169					  &in_obj, ACPI_TYPE_PACKAGE);
170	if (!out_obj)
171		return -EINVAL;
172
173	obj = &out_obj->package.elements[0];
174	status = obj->integer.value;
175	if (status != DSM_SUCCEED) {
176		obj = &out_obj->package.elements[1];
177		ext_status = obj->integer.value;
178		dev_dbg(pfrt_log_dev->parent_dev, "Error Status:%d\n", status);
179		dev_dbg(pfrt_log_dev->parent_dev, "Error Extend Status:%d\n", ext_status);
180		ret = -EBUSY;
181	}
182
183	ACPI_FREE(out_obj);
184
185	return ret;
186}
187
188static int get_pfrt_log_level(struct pfrt_log_device *pfrt_log_dev)
189{
190	acpi_handle handle = ACPI_HANDLE(pfrt_log_dev->parent_dev);
191	union acpi_object *out_obj, *obj;
192	enum pfru_dsm_status status, ext_status;
193	int ret = -EBUSY;
194
195	out_obj = acpi_evaluate_dsm_typed(handle, &pfrt_log_guid,
196					  pfrt_log_dev->info.log_revid, PFRT_FUNC_GET_LEV,
197					  NULL, ACPI_TYPE_PACKAGE);
198	if (!out_obj)
199		return -EINVAL;
200
201	obj = &out_obj->package.elements[0];
202	if (obj->type != ACPI_TYPE_INTEGER)
203		goto free_acpi_buffer;
204
205	status = obj->integer.value;
206	if (status != DSM_SUCCEED) {
207		obj = &out_obj->package.elements[1];
208		ext_status = obj->integer.value;
209		dev_dbg(pfrt_log_dev->parent_dev, "Error Status:%d\n", status);
210		dev_dbg(pfrt_log_dev->parent_dev, "Error Extend Status:%d\n", ext_status);
211		goto free_acpi_buffer;
212	}
213
214	obj = &out_obj->package.elements[2];
215	if (obj->type != ACPI_TYPE_INTEGER)
216		goto free_acpi_buffer;
217
218	ret = obj->integer.value;
219
220free_acpi_buffer:
221	ACPI_FREE(out_obj);
222
223	return ret;
224}
225
226static int valid_log_level(u32 level)
227{
228	return level == PFRT_LOG_ERR || level == PFRT_LOG_WARN ||
229	       level == PFRT_LOG_INFO || level == PFRT_LOG_VERB;
230}
231
232static int valid_log_type(u32 type)
233{
234	return type == PFRT_LOG_EXEC_IDX || type == PFRT_LOG_HISTORY_IDX;
235}
236
237static inline int valid_log_revid(u32 id)
238{
239	return id == PFRT_REVID_1 || id == PFRT_REVID_2;
240}
241
242static long pfrt_log_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
243{
244	struct pfrt_log_device *pfrt_log_dev = to_pfrt_log_dev(file);
245	struct pfrt_log_data_info data_info;
246	struct pfrt_log_info info;
247	void __user *p;
248	int ret = 0;
249
250	p = (void __user *)arg;
251
252	switch (cmd) {
253	case PFRT_LOG_IOC_SET_INFO:
254		if (copy_from_user(&info, p, sizeof(info)))
255			return -EFAULT;
256
257		if (valid_log_revid(info.log_revid))
258			pfrt_log_dev->info.log_revid = info.log_revid;
259
260		if (valid_log_level(info.log_level)) {
261			ret = set_pfrt_log_level(info.log_level, pfrt_log_dev);
262			if (ret < 0)
263				return ret;
264
265			pfrt_log_dev->info.log_level = info.log_level;
266		}
267
268		if (valid_log_type(info.log_type))
269			pfrt_log_dev->info.log_type = info.log_type;
270
271		return 0;
272
273	case PFRT_LOG_IOC_GET_INFO:
274		info.log_level = get_pfrt_log_level(pfrt_log_dev);
275		if (ret < 0)
276			return ret;
277
278		info.log_type = pfrt_log_dev->info.log_type;
279		info.log_revid = pfrt_log_dev->info.log_revid;
280		if (copy_to_user(p, &info, sizeof(info)))
281			return -EFAULT;
282
283		return 0;
284
285	case PFRT_LOG_IOC_GET_DATA_INFO:
286		ret = get_pfrt_log_data_info(&data_info, pfrt_log_dev);
287		if (ret)
288			return ret;
289
290		if (copy_to_user(p, &data_info, sizeof(struct pfrt_log_data_info)))
291			return -EFAULT;
292
293		return 0;
294
295	default:
296		return -ENOTTY;
297	}
298}
299
300static int
301pfrt_log_mmap(struct file *file, struct vm_area_struct *vma)
302{
303	struct pfrt_log_device *pfrt_log_dev;
304	struct pfrt_log_data_info info;
305	unsigned long psize, vsize;
306	phys_addr_t base_addr;
307	int ret;
308
309	if (vma->vm_flags & VM_WRITE)
310		return -EROFS;
311
312	/* changing from read to write with mprotect is not allowed */
313	vm_flags_clear(vma, VM_MAYWRITE);
314
315	pfrt_log_dev = to_pfrt_log_dev(file);
316
317	ret = get_pfrt_log_data_info(&info, pfrt_log_dev);
318	if (ret)
319		return ret;
320
321	base_addr = (phys_addr_t)((info.chunk2_addr_hi << 32) | info.chunk2_addr_lo);
322	/* pfrt update has not been launched yet */
323	if (!base_addr)
324		return -ENODEV;
325
326	psize = info.max_data_size;
327	/* base address and total buffer size must be page aligned */
328	if (!PAGE_ALIGNED(base_addr) || !PAGE_ALIGNED(psize))
329		return -ENODEV;
330
331	vsize = vma->vm_end - vma->vm_start;
332	if (vsize > psize)
333		return -EINVAL;
334
335	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
336	if (io_remap_pfn_range(vma, vma->vm_start, PFN_DOWN(base_addr),
337			       vsize, vma->vm_page_prot))
338		return -EAGAIN;
339
340	return 0;
341}
342
343static const struct file_operations acpi_pfrt_log_fops = {
344	.owner		= THIS_MODULE,
345	.mmap		= pfrt_log_mmap,
346	.unlocked_ioctl = pfrt_log_ioctl,
347	.llseek		= noop_llseek,
348};
349
350static void acpi_pfrt_log_remove(struct platform_device *pdev)
351{
352	struct pfrt_log_device *pfrt_log_dev = platform_get_drvdata(pdev);
353
354	misc_deregister(&pfrt_log_dev->miscdev);
355}
356
357static void pfrt_log_put_idx(void *data)
358{
359	struct pfrt_log_device *pfrt_log_dev = data;
360
361	ida_free(&pfrt_log_ida, pfrt_log_dev->index);
362}
363
364static int acpi_pfrt_log_probe(struct platform_device *pdev)
365{
366	acpi_handle handle = ACPI_HANDLE(&pdev->dev);
367	struct pfrt_log_device *pfrt_log_dev;
368	int ret;
369
370	if (!acpi_has_method(handle, "_DSM")) {
371		dev_dbg(&pdev->dev, "Missing _DSM\n");
372		return -ENODEV;
373	}
374
375	pfrt_log_dev = devm_kzalloc(&pdev->dev, sizeof(*pfrt_log_dev), GFP_KERNEL);
376	if (!pfrt_log_dev)
377		return -ENOMEM;
378
379	ret = ida_alloc(&pfrt_log_ida, GFP_KERNEL);
380	if (ret < 0)
381		return ret;
382
383	pfrt_log_dev->index = ret;
384	ret = devm_add_action_or_reset(&pdev->dev, pfrt_log_put_idx, pfrt_log_dev);
385	if (ret)
386		return ret;
387
388	pfrt_log_dev->info.log_revid = PFRT_DEFAULT_REV_ID;
389	pfrt_log_dev->parent_dev = &pdev->dev;
390
391	pfrt_log_dev->miscdev.minor = MISC_DYNAMIC_MINOR;
392	pfrt_log_dev->miscdev.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
393						    "pfrt%d",
394						    pfrt_log_dev->index);
395	if (!pfrt_log_dev->miscdev.name)
396		return -ENOMEM;
397
398	pfrt_log_dev->miscdev.nodename = devm_kasprintf(&pdev->dev, GFP_KERNEL,
399							"acpi_pfr_telemetry%d",
400							pfrt_log_dev->index);
401	if (!pfrt_log_dev->miscdev.nodename)
402		return -ENOMEM;
403
404	pfrt_log_dev->miscdev.fops = &acpi_pfrt_log_fops;
405	pfrt_log_dev->miscdev.parent = &pdev->dev;
406
407	ret = misc_register(&pfrt_log_dev->miscdev);
408	if (ret)
409		return ret;
410
411	platform_set_drvdata(pdev, pfrt_log_dev);
412
413	return 0;
414}
415
416static const struct acpi_device_id acpi_pfrt_log_ids[] = {
417	{"INTC1081"},
418	{}
419};
420MODULE_DEVICE_TABLE(acpi, acpi_pfrt_log_ids);
421
422static struct platform_driver acpi_pfrt_log_driver = {
423	.driver = {
424		.name = "pfr_telemetry",
425		.acpi_match_table = acpi_pfrt_log_ids,
426	},
427	.probe = acpi_pfrt_log_probe,
428	.remove_new = acpi_pfrt_log_remove,
429};
430module_platform_driver(acpi_pfrt_log_driver);
431
432MODULE_DESCRIPTION("Platform Firmware Runtime Update Telemetry driver");
433MODULE_LICENSE("GPL v2");
434