xref: /linux/drivers/platform/x86/amd/hsmp/acpi.c (revision 92c025db52bb94a032eb3d473bb81e62c19ddbd3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * AMD HSMP Platform Driver
4  * Copyright (c) 2024, AMD.
5  * All Rights Reserved.
6  *
7  * This file provides an ACPI based driver implementation for HSMP interface.
8  */
9 
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 
12 #include <asm/amd_hsmp.h>
13 
14 #include <linux/acpi.h>
15 #include <linux/device.h>
16 #include <linux/dev_printk.h>
17 #include <linux/ioport.h>
18 #include <linux/kstrtox.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/sysfs.h>
22 #include <linux/uuid.h>
23 
24 #include <uapi/asm-generic/errno-base.h>
25 
26 #include <asm/amd_node.h>
27 
28 #include "hsmp.h"
29 
30 #define DRIVER_NAME		"hsmp_acpi"
31 
32 /* These are the strings specified in ACPI table */
33 #define MSG_IDOFF_STR		"MsgIdOffset"
34 #define MSG_ARGOFF_STR		"MsgArgOffset"
35 #define MSG_RESPOFF_STR		"MsgRspOffset"
36 
37 static struct hsmp_plat_device *hsmp_pdev;
38 
39 static int amd_hsmp_acpi_rdwr(struct hsmp_socket *sock, u32 offset,
40 			      u32 *value, bool write)
41 {
42 	if (write)
43 		iowrite32(*value, sock->virt_base_addr + offset);
44 	else
45 		*value = ioread32(sock->virt_base_addr + offset);
46 
47 	return 0;
48 }
49 
50 /* This is the UUID used for HSMP */
51 static const guid_t acpi_hsmp_uuid = GUID_INIT(0xb74d619d, 0x5707, 0x48bd,
52 						0xa6, 0x9f, 0x4e, 0xa2,
53 						0x87, 0x1f, 0xc2, 0xf6);
54 
55 static inline bool is_acpi_hsmp_uuid(union acpi_object *obj)
56 {
57 	if (obj->type == ACPI_TYPE_BUFFER && obj->buffer.length == UUID_SIZE)
58 		return guid_equal((guid_t *)obj->buffer.pointer, &acpi_hsmp_uuid);
59 
60 	return false;
61 }
62 
63 static inline int hsmp_get_uid(struct device *dev, u16 *sock_ind)
64 {
65 	char *uid;
66 
67 	/*
68 	 * UID (ID00, ID01..IDXX) is used for differentiating sockets,
69 	 * read it and strip the "ID" part of it and convert the remaining
70 	 * bytes to integer.
71 	 */
72 	uid = acpi_device_uid(ACPI_COMPANION(dev));
73 
74 	return kstrtou16(uid + 2, 10, sock_ind);
75 }
76 
77 static acpi_status hsmp_resource(struct acpi_resource *res, void *data)
78 {
79 	struct hsmp_socket *sock = data;
80 	struct resource r;
81 
82 	switch (res->type) {
83 	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
84 		if (!acpi_dev_resource_memory(res, &r))
85 			return AE_ERROR;
86 		if (!r.start || r.end < r.start || !(r.flags & IORESOURCE_MEM_WRITEABLE))
87 			return AE_ERROR;
88 		sock->mbinfo.base_addr = r.start;
89 		sock->mbinfo.size = resource_size(&r);
90 		break;
91 	case ACPI_RESOURCE_TYPE_END_TAG:
92 		break;
93 	default:
94 		return AE_ERROR;
95 	}
96 
97 	return AE_OK;
98 }
99 
100 static int hsmp_read_acpi_dsd(struct hsmp_socket *sock)
101 {
102 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
103 	union acpi_object *guid, *mailbox_package;
104 	union acpi_object *dsd;
105 	acpi_status status;
106 	int ret = 0;
107 	int j;
108 
109 	status = acpi_evaluate_object_typed(ACPI_HANDLE(sock->dev), "_DSD", NULL,
110 					    &buf, ACPI_TYPE_PACKAGE);
111 	if (ACPI_FAILURE(status)) {
112 		dev_err(sock->dev, "Failed to read mailbox reg offsets from DSD table, err: %s\n",
113 			acpi_format_exception(status));
114 		return -ENODEV;
115 	}
116 
117 	dsd = buf.pointer;
118 
119 	/* HSMP _DSD property should contain 2 objects.
120 	 * 1. guid which is an acpi object of type ACPI_TYPE_BUFFER
121 	 * 2. mailbox which is an acpi object of type ACPI_TYPE_PACKAGE
122 	 *    This mailbox object contains 3 more acpi objects of type
123 	 *    ACPI_TYPE_PACKAGE for holding msgid, msgresp, msgarg offsets
124 	 *    these packages inturn contain 2 acpi objects of type
125 	 *    ACPI_TYPE_STRING and ACPI_TYPE_INTEGER
126 	 */
127 	if (!dsd || dsd->type != ACPI_TYPE_PACKAGE || dsd->package.count != 2) {
128 		ret = -EINVAL;
129 		goto free_buf;
130 	}
131 
132 	guid = &dsd->package.elements[0];
133 	mailbox_package = &dsd->package.elements[1];
134 	if (!is_acpi_hsmp_uuid(guid) || mailbox_package->type != ACPI_TYPE_PACKAGE) {
135 		dev_err(sock->dev, "Invalid hsmp _DSD table data\n");
136 		ret = -EINVAL;
137 		goto free_buf;
138 	}
139 
140 	for (j = 0; j < mailbox_package->package.count; j++) {
141 		union acpi_object *msgobj, *msgstr, *msgint;
142 
143 		msgobj	= &mailbox_package->package.elements[j];
144 		msgstr	= &msgobj->package.elements[0];
145 		msgint	= &msgobj->package.elements[1];
146 
147 		/* package should have 1 string and 1 integer object */
148 		if (msgobj->type != ACPI_TYPE_PACKAGE ||
149 		    msgstr->type != ACPI_TYPE_STRING ||
150 		    msgint->type != ACPI_TYPE_INTEGER) {
151 			ret = -EINVAL;
152 			goto free_buf;
153 		}
154 
155 		if (!strncmp(msgstr->string.pointer, MSG_IDOFF_STR,
156 			     msgstr->string.length)) {
157 			sock->mbinfo.msg_id_off = msgint->integer.value;
158 		} else if (!strncmp(msgstr->string.pointer, MSG_RESPOFF_STR,
159 				    msgstr->string.length)) {
160 			sock->mbinfo.msg_resp_off =  msgint->integer.value;
161 		} else if (!strncmp(msgstr->string.pointer, MSG_ARGOFF_STR,
162 				    msgstr->string.length)) {
163 			sock->mbinfo.msg_arg_off = msgint->integer.value;
164 		} else {
165 			ret = -ENOENT;
166 			goto free_buf;
167 		}
168 	}
169 
170 	if (!sock->mbinfo.msg_id_off || !sock->mbinfo.msg_resp_off ||
171 	    !sock->mbinfo.msg_arg_off)
172 		ret = -EINVAL;
173 
174 free_buf:
175 	ACPI_FREE(buf.pointer);
176 	return ret;
177 }
178 
179 static int hsmp_read_acpi_crs(struct hsmp_socket *sock)
180 {
181 	acpi_status status;
182 
183 	status = acpi_walk_resources(ACPI_HANDLE(sock->dev), METHOD_NAME__CRS,
184 				     hsmp_resource, sock);
185 	if (ACPI_FAILURE(status)) {
186 		dev_err(sock->dev, "Failed to look up MP1 base address from CRS method, err: %s\n",
187 			acpi_format_exception(status));
188 		return -EINVAL;
189 	}
190 	if (!sock->mbinfo.base_addr || !sock->mbinfo.size)
191 		return -EINVAL;
192 
193 	/* The mapped region should be un-cached */
194 	sock->virt_base_addr = devm_ioremap_uc(sock->dev, sock->mbinfo.base_addr,
195 					       sock->mbinfo.size);
196 	if (!sock->virt_base_addr) {
197 		dev_err(sock->dev, "Failed to ioremap MP1 base address\n");
198 		return -ENOMEM;
199 	}
200 
201 	return 0;
202 }
203 
204 /* Parse the ACPI table to read the data */
205 static int hsmp_parse_acpi_table(struct device *dev, u16 sock_ind)
206 {
207 	struct hsmp_socket *sock = &hsmp_pdev->sock[sock_ind];
208 	int ret;
209 
210 	sock->sock_ind		= sock_ind;
211 	sock->dev		= dev;
212 	sock->amd_hsmp_rdwr	= amd_hsmp_acpi_rdwr;
213 
214 	sema_init(&sock->hsmp_sem, 1);
215 
216 	dev_set_drvdata(dev, sock);
217 
218 	/* Read MP1 base address from CRS method */
219 	ret = hsmp_read_acpi_crs(sock);
220 	if (ret)
221 		return ret;
222 
223 	/* Read mailbox offsets from DSD table */
224 	return hsmp_read_acpi_dsd(sock);
225 }
226 
227 static ssize_t hsmp_metric_tbl_acpi_read(struct file *filp, struct kobject *kobj,
228 					 const struct bin_attribute *bin_attr, char *buf,
229 					 loff_t off, size_t count)
230 {
231 	struct device *dev = container_of(kobj, struct device, kobj);
232 	struct hsmp_socket *sock = dev_get_drvdata(dev);
233 
234 	return hsmp_metric_tbl_read(sock, buf, count);
235 }
236 
237 static umode_t hsmp_is_sock_attr_visible(struct kobject *kobj,
238 					 const struct bin_attribute *battr, int id)
239 {
240 	if (hsmp_pdev->proto_ver == HSMP_PROTO_VER6)
241 		return battr->attr.mode;
242 
243 	return 0;
244 }
245 
246 static int init_acpi(struct device *dev)
247 {
248 	u16 sock_ind;
249 	int ret;
250 
251 	ret = hsmp_get_uid(dev, &sock_ind);
252 	if (ret)
253 		return ret;
254 	if (sock_ind >= hsmp_pdev->num_sockets)
255 		return -EINVAL;
256 
257 	ret = hsmp_parse_acpi_table(dev, sock_ind);
258 	if (ret) {
259 		dev_err(dev, "Failed to parse ACPI table\n");
260 		return ret;
261 	}
262 
263 	/* Test the hsmp interface */
264 	ret = hsmp_test(sock_ind, 0xDEADBEEF);
265 	if (ret) {
266 		dev_err(dev, "HSMP test message failed on Fam:%x model:%x\n",
267 			boot_cpu_data.x86, boot_cpu_data.x86_model);
268 		dev_err(dev, "Is HSMP disabled in BIOS ?\n");
269 		return ret;
270 	}
271 
272 	ret = hsmp_cache_proto_ver(sock_ind);
273 	if (ret) {
274 		dev_err(dev, "Failed to read HSMP protocol version\n");
275 		return ret;
276 	}
277 
278 	if (hsmp_pdev->proto_ver == HSMP_PROTO_VER6) {
279 		ret = hsmp_get_tbl_dram_base(sock_ind);
280 		if (ret)
281 			dev_err(dev, "Failed to init metric table\n");
282 	}
283 
284 	ret = hsmp_create_sensor(dev, sock_ind);
285 	if (ret)
286 		dev_err(dev, "Failed to register HSMP sensors with hwmon\n");
287 
288 	return ret;
289 }
290 
291 static const struct bin_attribute  hsmp_metric_tbl_attr = {
292 	.attr = { .name = HSMP_METRICS_TABLE_NAME, .mode = 0444},
293 	.read_new = hsmp_metric_tbl_acpi_read,
294 	.size = sizeof(struct hsmp_metric_table),
295 };
296 
297 static const struct bin_attribute *hsmp_attr_list[] = {
298 	&hsmp_metric_tbl_attr,
299 	NULL
300 };
301 
302 static const struct attribute_group hsmp_attr_grp = {
303 	.bin_attrs_new = hsmp_attr_list,
304 	.is_bin_visible = hsmp_is_sock_attr_visible,
305 };
306 
307 static const struct attribute_group *hsmp_groups[] = {
308 	&hsmp_attr_grp,
309 	NULL
310 };
311 
312 static const struct acpi_device_id amd_hsmp_acpi_ids[] = {
313 	{ACPI_HSMP_DEVICE_HID, 0},
314 	{}
315 };
316 MODULE_DEVICE_TABLE(acpi, amd_hsmp_acpi_ids);
317 
318 static int hsmp_acpi_probe(struct platform_device *pdev)
319 {
320 	int ret;
321 
322 	hsmp_pdev = get_hsmp_pdev();
323 	if (!hsmp_pdev)
324 		return -ENOMEM;
325 
326 	if (!hsmp_pdev->is_probed) {
327 		hsmp_pdev->num_sockets = amd_num_nodes();
328 		if (hsmp_pdev->num_sockets == 0 || hsmp_pdev->num_sockets > MAX_AMD_NUM_NODES)
329 			return -ENODEV;
330 
331 		hsmp_pdev->sock = devm_kcalloc(&pdev->dev, hsmp_pdev->num_sockets,
332 					       sizeof(*hsmp_pdev->sock),
333 					       GFP_KERNEL);
334 		if (!hsmp_pdev->sock)
335 			return -ENOMEM;
336 	}
337 
338 	ret = init_acpi(&pdev->dev);
339 	if (ret) {
340 		dev_err(&pdev->dev, "Failed to initialize HSMP interface.\n");
341 		return ret;
342 	}
343 
344 	if (!hsmp_pdev->is_probed) {
345 		ret = hsmp_misc_register(&pdev->dev);
346 		if (ret)
347 			return ret;
348 		hsmp_pdev->is_probed = true;
349 	}
350 
351 	return 0;
352 }
353 
354 static void hsmp_acpi_remove(struct platform_device *pdev)
355 {
356 	/*
357 	 * We register only one misc_device even on multi-socket system.
358 	 * So, deregister should happen only once.
359 	 */
360 	if (hsmp_pdev->is_probed) {
361 		hsmp_misc_deregister();
362 		hsmp_pdev->is_probed = false;
363 	}
364 }
365 
366 static struct platform_driver amd_hsmp_driver = {
367 	.probe		= hsmp_acpi_probe,
368 	.remove		= hsmp_acpi_remove,
369 	.driver		= {
370 		.name	= DRIVER_NAME,
371 		.acpi_match_table = amd_hsmp_acpi_ids,
372 		.dev_groups = hsmp_groups,
373 	},
374 };
375 
376 module_platform_driver(amd_hsmp_driver);
377 
378 MODULE_IMPORT_NS("AMD_HSMP");
379 MODULE_DESCRIPTION("AMD HSMP Platform Interface Driver");
380 MODULE_VERSION(DRIVER_VERSION);
381 MODULE_LICENSE("GPL");
382