xref: /linux/drivers/platform/x86/intel/pmt/class.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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: "Alexander Duyck" <alexander.h.duyck@linux.intel.com>
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/intel_vsec.h>
13 #include <linux/io-64-nonatomic-lo-hi.h>
14 #include <linux/module.h>
15 #include <linux/mm.h>
16 #include <linux/pci.h>
17 
18 #include "class.h"
19 
20 #define PMT_XA_START		1
21 #define PMT_XA_MAX		INT_MAX
22 #define PMT_XA_LIMIT		XA_LIMIT(PMT_XA_START, PMT_XA_MAX)
23 #define GUID_SPR_PUNIT		0x9956f43f
24 
25 bool intel_pmt_is_early_client_hw(struct device *dev)
26 {
27 	struct intel_vsec_device *ivdev = dev_to_ivdev(dev);
28 
29 	/*
30 	 * Early implementations of PMT on client platforms have some
31 	 * differences from the server platforms (which use the Out Of Band
32 	 * Management Services Module OOBMSM).
33 	 */
34 	return !!(ivdev->quirks & VSEC_QUIRK_EARLY_HW);
35 }
36 EXPORT_SYMBOL_NS_GPL(intel_pmt_is_early_client_hw, INTEL_PMT);
37 
38 static inline int
39 pmt_memcpy64_fromio(void *to, const u64 __iomem *from, size_t count)
40 {
41 	int i, remain;
42 	u64 *buf = to;
43 
44 	if (!IS_ALIGNED((unsigned long)from, 8))
45 		return -EFAULT;
46 
47 	for (i = 0; i < count/8; i++)
48 		buf[i] = readq(&from[i]);
49 
50 	/* Copy any remaining bytes */
51 	remain = count % 8;
52 	if (remain) {
53 		u64 tmp = readq(&from[i]);
54 
55 		memcpy(&buf[i], &tmp, remain);
56 	}
57 
58 	return count;
59 }
60 
61 int pmt_telem_read_mmio(struct pci_dev *pdev, struct pmt_callbacks *cb, u32 guid, void *buf,
62 			void __iomem *addr, loff_t off, u32 count)
63 {
64 	if (cb && cb->read_telem)
65 		return cb->read_telem(pdev, guid, buf, off, count);
66 
67 	addr += off;
68 
69 	if (guid == GUID_SPR_PUNIT)
70 		/* PUNIT on SPR only supports aligned 64-bit read */
71 		return pmt_memcpy64_fromio(buf, addr, count);
72 
73 	memcpy_fromio(buf, addr, count);
74 
75 	return count;
76 }
77 EXPORT_SYMBOL_NS_GPL(pmt_telem_read_mmio, INTEL_PMT);
78 
79 /*
80  * sysfs
81  */
82 static ssize_t
83 intel_pmt_read(struct file *filp, struct kobject *kobj,
84 	       struct bin_attribute *attr, char *buf, loff_t off,
85 	       size_t count)
86 {
87 	struct intel_pmt_entry *entry = container_of(attr,
88 						     struct intel_pmt_entry,
89 						     pmt_bin_attr);
90 
91 	if (off < 0)
92 		return -EINVAL;
93 
94 	if (off >= entry->size)
95 		return 0;
96 
97 	if (count > entry->size - off)
98 		count = entry->size - off;
99 
100 	count = pmt_telem_read_mmio(entry->ep->pcidev, entry->cb, entry->header.guid, buf,
101 				    entry->base, off, count);
102 
103 	return count;
104 }
105 
106 static int
107 intel_pmt_mmap(struct file *filp, struct kobject *kobj,
108 		const struct bin_attribute *attr, struct vm_area_struct *vma)
109 {
110 	struct intel_pmt_entry *entry = container_of(attr,
111 						     struct intel_pmt_entry,
112 						     pmt_bin_attr);
113 	unsigned long vsize = vma->vm_end - vma->vm_start;
114 	struct device *dev = kobj_to_dev(kobj);
115 	unsigned long phys = entry->base_addr;
116 	unsigned long pfn = PFN_DOWN(phys);
117 	unsigned long psize;
118 
119 	if (vma->vm_flags & (VM_WRITE | VM_MAYWRITE))
120 		return -EROFS;
121 
122 	psize = (PFN_UP(entry->base_addr + entry->size) - pfn) * PAGE_SIZE;
123 	if (vsize > psize) {
124 		dev_err(dev, "Requested mmap size is too large\n");
125 		return -EINVAL;
126 	}
127 
128 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
129 	if (io_remap_pfn_range(vma, vma->vm_start, pfn,
130 		vsize, vma->vm_page_prot))
131 		return -EAGAIN;
132 
133 	return 0;
134 }
135 
136 static ssize_t
137 guid_show(struct device *dev, struct device_attribute *attr, char *buf)
138 {
139 	struct intel_pmt_entry *entry = dev_get_drvdata(dev);
140 
141 	return sprintf(buf, "0x%x\n", entry->guid);
142 }
143 static DEVICE_ATTR_RO(guid);
144 
145 static ssize_t size_show(struct device *dev, struct device_attribute *attr,
146 			 char *buf)
147 {
148 	struct intel_pmt_entry *entry = dev_get_drvdata(dev);
149 
150 	return sprintf(buf, "%zu\n", entry->size);
151 }
152 static DEVICE_ATTR_RO(size);
153 
154 static ssize_t
155 offset_show(struct device *dev, struct device_attribute *attr, char *buf)
156 {
157 	struct intel_pmt_entry *entry = dev_get_drvdata(dev);
158 
159 	return sprintf(buf, "%lu\n", offset_in_page(entry->base_addr));
160 }
161 static DEVICE_ATTR_RO(offset);
162 
163 static struct attribute *intel_pmt_attrs[] = {
164 	&dev_attr_guid.attr,
165 	&dev_attr_size.attr,
166 	&dev_attr_offset.attr,
167 	NULL
168 };
169 ATTRIBUTE_GROUPS(intel_pmt);
170 
171 static struct class intel_pmt_class = {
172 	.name = "intel_pmt",
173 	.dev_groups = intel_pmt_groups,
174 };
175 
176 static int intel_pmt_populate_entry(struct intel_pmt_entry *entry,
177 				    struct intel_vsec_device *ivdev,
178 				    struct resource *disc_res)
179 {
180 	struct pci_dev *pci_dev = ivdev->pcidev;
181 	struct device *dev = &ivdev->auxdev.dev;
182 	struct intel_pmt_header *header = &entry->header;
183 	u8 bir;
184 
185 	/*
186 	 * The base offset should always be 8 byte aligned.
187 	 *
188 	 * For non-local access types the lower 3 bits of base offset
189 	 * contains the index of the base address register where the
190 	 * telemetry can be found.
191 	 */
192 	bir = GET_BIR(header->base_offset);
193 
194 	/* Local access and BARID only for now */
195 	switch (header->access_type) {
196 	case ACCESS_LOCAL:
197 		if (bir) {
198 			dev_err(dev,
199 				"Unsupported BAR index %d for access type %d\n",
200 				bir, header->access_type);
201 			return -EINVAL;
202 		}
203 		/*
204 		 * For access_type LOCAL, the base address is as follows:
205 		 * base address = end of discovery region + base offset
206 		 */
207 		entry->base_addr = disc_res->end + 1 + header->base_offset;
208 
209 		/*
210 		 * Some hardware use a different calculation for the base address
211 		 * when access_type == ACCESS_LOCAL. On the these systems
212 		 * ACCESS_LOCAL refers to an address in the same BAR as the
213 		 * header but at a fixed offset. But as the header address was
214 		 * supplied to the driver, we don't know which BAR it was in.
215 		 * So search for the bar whose range includes the header address.
216 		 */
217 		if (intel_pmt_is_early_client_hw(dev)) {
218 			int i;
219 
220 			entry->base_addr = 0;
221 			for (i = 0; i < 6; i++)
222 				if (disc_res->start >= pci_resource_start(pci_dev, i) &&
223 				   (disc_res->start <= pci_resource_end(pci_dev, i))) {
224 					entry->base_addr = pci_resource_start(pci_dev, i) +
225 							   header->base_offset;
226 					break;
227 				}
228 			if (!entry->base_addr)
229 				return -EINVAL;
230 		}
231 
232 		break;
233 	case ACCESS_BARID:
234 		/* Use the provided base address if it exists */
235 		if (ivdev->base_addr) {
236 			entry->base_addr = ivdev->base_addr +
237 				   GET_ADDRESS(header->base_offset);
238 			break;
239 		}
240 
241 		/*
242 		 * If another BAR was specified then the base offset
243 		 * represents the offset within that BAR. SO retrieve the
244 		 * address from the parent PCI device and add offset.
245 		 */
246 		entry->base_addr = pci_resource_start(pci_dev, bir) +
247 				   GET_ADDRESS(header->base_offset);
248 		break;
249 	default:
250 		dev_err(dev, "Unsupported access type %d\n",
251 			header->access_type);
252 		return -EINVAL;
253 	}
254 
255 	entry->guid = header->guid;
256 	entry->size = header->size;
257 	entry->cb = ivdev->priv_data;
258 
259 	return 0;
260 }
261 
262 static int intel_pmt_dev_register(struct intel_pmt_entry *entry,
263 				  struct intel_pmt_namespace *ns,
264 				  struct device *parent)
265 {
266 	struct intel_vsec_device *ivdev = dev_to_ivdev(parent);
267 	struct resource res = {0};
268 	struct device *dev;
269 	int ret;
270 
271 	ret = xa_alloc(ns->xa, &entry->devid, entry, PMT_XA_LIMIT, GFP_KERNEL);
272 	if (ret)
273 		return ret;
274 
275 	dev = device_create(&intel_pmt_class, parent, MKDEV(0, 0), entry,
276 			    "%s%d", ns->name, entry->devid);
277 
278 	if (IS_ERR(dev)) {
279 		dev_err(parent, "Could not create %s%d device node\n",
280 			ns->name, entry->devid);
281 		ret = PTR_ERR(dev);
282 		goto fail_dev_create;
283 	}
284 
285 	entry->kobj = &dev->kobj;
286 
287 	if (ns->attr_grp) {
288 		ret = sysfs_create_group(entry->kobj, ns->attr_grp);
289 		if (ret)
290 			goto fail_sysfs_create_group;
291 	}
292 
293 	/* if size is 0 assume no data buffer, so no file needed */
294 	if (!entry->size)
295 		return 0;
296 
297 	res.start = entry->base_addr;
298 	res.end = res.start + entry->size - 1;
299 	res.flags = IORESOURCE_MEM;
300 
301 	entry->base = devm_ioremap_resource(dev, &res);
302 	if (IS_ERR(entry->base)) {
303 		ret = PTR_ERR(entry->base);
304 		goto fail_ioremap;
305 	}
306 
307 	sysfs_bin_attr_init(&entry->pmt_bin_attr);
308 	entry->pmt_bin_attr.attr.name = ns->name;
309 	entry->pmt_bin_attr.attr.mode = 0440;
310 	entry->pmt_bin_attr.mmap = intel_pmt_mmap;
311 	entry->pmt_bin_attr.read = intel_pmt_read;
312 	entry->pmt_bin_attr.size = entry->size;
313 
314 	ret = sysfs_create_bin_file(&dev->kobj, &entry->pmt_bin_attr);
315 	if (ret)
316 		goto fail_ioremap;
317 
318 	if (ns->pmt_add_endpoint) {
319 		ret = ns->pmt_add_endpoint(ivdev, entry);
320 		if (ret)
321 			goto fail_add_endpoint;
322 	}
323 
324 	return 0;
325 
326 fail_add_endpoint:
327 	sysfs_remove_bin_file(entry->kobj, &entry->pmt_bin_attr);
328 fail_ioremap:
329 	if (ns->attr_grp)
330 		sysfs_remove_group(entry->kobj, ns->attr_grp);
331 fail_sysfs_create_group:
332 	device_unregister(dev);
333 fail_dev_create:
334 	xa_erase(ns->xa, entry->devid);
335 
336 	return ret;
337 }
338 
339 int intel_pmt_dev_create(struct intel_pmt_entry *entry, struct intel_pmt_namespace *ns,
340 			 struct intel_vsec_device *intel_vsec_dev, int idx)
341 {
342 	struct device *dev = &intel_vsec_dev->auxdev.dev;
343 	struct resource	*disc_res;
344 	int ret;
345 
346 	disc_res = &intel_vsec_dev->resource[idx];
347 
348 	entry->disc_table = devm_ioremap_resource(dev, disc_res);
349 	if (IS_ERR(entry->disc_table))
350 		return PTR_ERR(entry->disc_table);
351 
352 	ret = ns->pmt_header_decode(entry, dev);
353 	if (ret)
354 		return ret;
355 
356 	ret = intel_pmt_populate_entry(entry, intel_vsec_dev, disc_res);
357 	if (ret)
358 		return ret;
359 
360 	return intel_pmt_dev_register(entry, ns, dev);
361 }
362 EXPORT_SYMBOL_NS_GPL(intel_pmt_dev_create, INTEL_PMT);
363 
364 void intel_pmt_dev_destroy(struct intel_pmt_entry *entry,
365 			   struct intel_pmt_namespace *ns)
366 {
367 	struct device *dev = kobj_to_dev(entry->kobj);
368 
369 	if (entry->size)
370 		sysfs_remove_bin_file(entry->kobj, &entry->pmt_bin_attr);
371 
372 	if (ns->attr_grp)
373 		sysfs_remove_group(entry->kobj, ns->attr_grp);
374 
375 	device_unregister(dev);
376 	xa_erase(ns->xa, entry->devid);
377 }
378 EXPORT_SYMBOL_NS_GPL(intel_pmt_dev_destroy, INTEL_PMT);
379 
380 static int __init pmt_class_init(void)
381 {
382 	return class_register(&intel_pmt_class);
383 }
384 
385 static void __exit pmt_class_exit(void)
386 {
387 	class_unregister(&intel_pmt_class);
388 }
389 
390 module_init(pmt_class_init);
391 module_exit(pmt_class_exit);
392 
393 MODULE_AUTHOR("Alexander Duyck <alexander.h.duyck@linux.intel.com>");
394 MODULE_DESCRIPTION("Intel PMT Class driver");
395 MODULE_LICENSE("GPL v2");
396