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