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 platform device implementations.
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/build_bug.h>
16 #include <linux/device.h>
17 #include <linux/module.h>
18 #include <linux/pci.h>
19 #include <linux/platform_device.h>
20 #include <linux/sysfs.h>
21 
22 #include <asm/amd/node.h>
23 
24 #include "hsmp.h"
25 
26 #define DRIVER_NAME		"amd_hsmp"
27 
28 /*
29  * To access specific HSMP mailbox register, s/w writes the SMN address of HSMP mailbox
30  * register into the SMN_INDEX register, and reads/writes the SMN_DATA reg.
31  * Below are required SMN address for HSMP Mailbox register offsets in SMU address space
32  */
33 #define SMN_HSMP_BASE		0x3B00000
34 #define SMN_HSMP_MSG_ID		0x0010534
35 #define SMN_HSMP_MSG_ID_F1A_M0H	0x0010934
36 #define SMN_HSMP_MSG_RESP	0x0010980
37 #define SMN_HSMP_MSG_DATA	0x00109E0
38 
39 static struct hsmp_plat_device *hsmp_pdev;
40 
41 static int amd_hsmp_pci_rdwr(struct hsmp_socket *sock, u32 offset,
42 			     u32 *value, bool write)
43 {
44 	return amd_smn_hsmp_rdwr(sock->sock_ind, sock->mbinfo.base_addr + offset, value, write);
45 }
46 
47 static ssize_t hsmp_metric_tbl_plat_read(struct file *filp, struct kobject *kobj,
48 					 const struct bin_attribute *bin_attr, char *buf,
49 					 loff_t off, size_t count)
50 {
51 	struct hsmp_socket *sock;
52 	u16 sock_ind;
53 
54 	sock_ind = (uintptr_t)bin_attr->private;
55 	if (sock_ind >= hsmp_pdev->num_sockets)
56 		return -EINVAL;
57 
58 	sock = &hsmp_pdev->sock[sock_ind];
59 
60 	return hsmp_metric_tbl_read(sock, buf, count);
61 }
62 
63 static umode_t hsmp_is_sock_attr_visible(struct kobject *kobj,
64 					 const struct bin_attribute *battr, int id)
65 {
66 	u16 sock_ind;
67 
68 	sock_ind = (uintptr_t)battr->private;
69 
70 	if (id == 0 && sock_ind >= hsmp_pdev->num_sockets)
71 		return SYSFS_GROUP_INVISIBLE;
72 
73 	if (hsmp_pdev->proto_ver == HSMP_PROTO_VER6)
74 		return battr->attr.mode;
75 
76 	return 0;
77 }
78 
79 /*
80  * AMD supports maximum of 8 sockets in a system.
81  * Static array of 8 + 1(for NULL) elements is created below
82  * to create sysfs groups for sockets.
83  * is_bin_visible function is used to show / hide the necessary groups.
84  *
85  * Validate the maximum number against MAX_AMD_NUM_NODES. If this changes,
86  * then the attributes and groups below must be adjusted.
87  */
88 static_assert(MAX_AMD_NUM_NODES == 8);
89 
90 #define HSMP_BIN_ATTR(index, _list)					\
91 static const struct bin_attribute attr##index = {			\
92 	.attr = { .name = HSMP_METRICS_TABLE_NAME, .mode = 0444},	\
93 	.private = (void *)index,					\
94 	.read_new = hsmp_metric_tbl_plat_read,				\
95 	.size = sizeof(struct hsmp_metric_table),			\
96 };									\
97 static const struct bin_attribute _list[] = {				\
98 	&attr##index,							\
99 	NULL								\
100 }
101 
102 HSMP_BIN_ATTR(0, *sock0_attr_list);
103 HSMP_BIN_ATTR(1, *sock1_attr_list);
104 HSMP_BIN_ATTR(2, *sock2_attr_list);
105 HSMP_BIN_ATTR(3, *sock3_attr_list);
106 HSMP_BIN_ATTR(4, *sock4_attr_list);
107 HSMP_BIN_ATTR(5, *sock5_attr_list);
108 HSMP_BIN_ATTR(6, *sock6_attr_list);
109 HSMP_BIN_ATTR(7, *sock7_attr_list);
110 
111 #define HSMP_BIN_ATTR_GRP(index, _list, _name)			\
112 static const struct attribute_group sock##index##_attr_grp = {	\
113 	.bin_attrs_new = _list,					\
114 	.is_bin_visible = hsmp_is_sock_attr_visible,		\
115 	.name = #_name,						\
116 }
117 
118 HSMP_BIN_ATTR_GRP(0, sock0_attr_list, socket0);
119 HSMP_BIN_ATTR_GRP(1, sock1_attr_list, socket1);
120 HSMP_BIN_ATTR_GRP(2, sock2_attr_list, socket2);
121 HSMP_BIN_ATTR_GRP(3, sock3_attr_list, socket3);
122 HSMP_BIN_ATTR_GRP(4, sock4_attr_list, socket4);
123 HSMP_BIN_ATTR_GRP(5, sock5_attr_list, socket5);
124 HSMP_BIN_ATTR_GRP(6, sock6_attr_list, socket6);
125 HSMP_BIN_ATTR_GRP(7, sock7_attr_list, socket7);
126 
127 static const struct attribute_group *hsmp_groups[] = {
128 	&sock0_attr_grp,
129 	&sock1_attr_grp,
130 	&sock2_attr_grp,
131 	&sock3_attr_grp,
132 	&sock4_attr_grp,
133 	&sock5_attr_grp,
134 	&sock6_attr_grp,
135 	&sock7_attr_grp,
136 	NULL
137 };
138 
139 static inline bool is_f1a_m0h(void)
140 {
141 	if (boot_cpu_data.x86 == 0x1A && boot_cpu_data.x86_model <= 0x0F)
142 		return true;
143 
144 	return false;
145 }
146 
147 static int init_platform_device(struct device *dev)
148 {
149 	struct hsmp_socket *sock;
150 	int ret, i;
151 
152 	for (i = 0; i < hsmp_pdev->num_sockets; i++) {
153 		sock = &hsmp_pdev->sock[i];
154 		sock->sock_ind			= i;
155 		sock->dev			= dev;
156 		sock->mbinfo.base_addr		= SMN_HSMP_BASE;
157 		sock->amd_hsmp_rdwr		= amd_hsmp_pci_rdwr;
158 
159 		/*
160 		 * This is a transitional change from non-ACPI to ACPI, only
161 		 * family 0x1A, model 0x00 platform is supported for both ACPI and non-ACPI.
162 		 */
163 		if (is_f1a_m0h())
164 			sock->mbinfo.msg_id_off	= SMN_HSMP_MSG_ID_F1A_M0H;
165 		else
166 			sock->mbinfo.msg_id_off	= SMN_HSMP_MSG_ID;
167 
168 		sock->mbinfo.msg_resp_off	= SMN_HSMP_MSG_RESP;
169 		sock->mbinfo.msg_arg_off	= SMN_HSMP_MSG_DATA;
170 		sema_init(&sock->hsmp_sem, 1);
171 
172 		/* Test the hsmp interface on each socket */
173 		ret = hsmp_test(i, 0xDEADBEEF);
174 		if (ret) {
175 			dev_err(dev, "HSMP test message failed on Fam:%x model:%x\n",
176 				boot_cpu_data.x86, boot_cpu_data.x86_model);
177 			dev_err(dev, "Is HSMP disabled in BIOS ?\n");
178 			return ret;
179 		}
180 
181 		ret = hsmp_cache_proto_ver(i);
182 		if (ret) {
183 			dev_err(dev, "Failed to read HSMP protocol version\n");
184 			return ret;
185 		}
186 
187 		if (hsmp_pdev->proto_ver == HSMP_PROTO_VER6) {
188 			ret = hsmp_get_tbl_dram_base(i);
189 			if (ret)
190 				dev_err(dev, "Failed to init metric table\n");
191 		}
192 
193 		/* Register with hwmon interface for reporting power */
194 		ret = hsmp_create_sensor(dev, i);
195 		if (ret)
196 			dev_err(dev, "Failed to register HSMP sensors with hwmon\n");
197 	}
198 
199 	return 0;
200 }
201 
202 static int hsmp_pltdrv_probe(struct platform_device *pdev)
203 {
204 	int ret;
205 
206 	hsmp_pdev->sock = devm_kcalloc(&pdev->dev, hsmp_pdev->num_sockets,
207 				       sizeof(*hsmp_pdev->sock),
208 				       GFP_KERNEL);
209 	if (!hsmp_pdev->sock)
210 		return -ENOMEM;
211 
212 	ret = init_platform_device(&pdev->dev);
213 	if (ret) {
214 		dev_err(&pdev->dev, "Failed to init HSMP mailbox\n");
215 		return ret;
216 	}
217 
218 	return hsmp_misc_register(&pdev->dev);
219 }
220 
221 static void hsmp_pltdrv_remove(struct platform_device *pdev)
222 {
223 	hsmp_misc_deregister();
224 }
225 
226 static struct platform_driver amd_hsmp_driver = {
227 	.probe		= hsmp_pltdrv_probe,
228 	.remove		= hsmp_pltdrv_remove,
229 	.driver		= {
230 		.name	= DRIVER_NAME,
231 		.dev_groups = hsmp_groups,
232 	},
233 };
234 
235 static struct platform_device *amd_hsmp_platdev;
236 
237 static int hsmp_plat_dev_register(void)
238 {
239 	int ret;
240 
241 	amd_hsmp_platdev = platform_device_alloc(DRIVER_NAME, PLATFORM_DEVID_NONE);
242 	if (!amd_hsmp_platdev)
243 		return -ENOMEM;
244 
245 	ret = platform_device_add(amd_hsmp_platdev);
246 	if (ret)
247 		platform_device_put(amd_hsmp_platdev);
248 
249 	return ret;
250 }
251 
252 /*
253  * This check is only needed for backward compatibility of previous platforms.
254  * All new platforms are expected to support ACPI based probing.
255  */
256 static bool legacy_hsmp_support(void)
257 {
258 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
259 		return false;
260 
261 	switch (boot_cpu_data.x86) {
262 	case 0x19:
263 		switch (boot_cpu_data.x86_model) {
264 		case 0x00 ... 0x1F:
265 		case 0x30 ... 0x3F:
266 		case 0x90 ... 0x9F:
267 		case 0xA0 ... 0xAF:
268 			return true;
269 		default:
270 			return false;
271 		}
272 	case 0x1A:
273 		switch (boot_cpu_data.x86_model) {
274 		case 0x00 ... 0x0F:
275 			return true;
276 		default:
277 			return false;
278 		}
279 	default:
280 		return false;
281 	}
282 
283 	return false;
284 }
285 
286 static int __init hsmp_plt_init(void)
287 {
288 	int ret = -ENODEV;
289 
290 	if (!legacy_hsmp_support()) {
291 		pr_info("HSMP is not supported on Family:%x model:%x\n",
292 			boot_cpu_data.x86, boot_cpu_data.x86_model);
293 		return ret;
294 	}
295 
296 	if (acpi_dev_present(ACPI_HSMP_DEVICE_HID, NULL, -1))
297 		return -ENODEV;
298 
299 	hsmp_pdev = get_hsmp_pdev();
300 	if (!hsmp_pdev)
301 		return -ENOMEM;
302 
303 	/*
304 	 * amd_num_nodes() returns number of SMN/DF interfaces present in the system
305 	 * if we have N SMN/DF interfaces that ideally means N sockets
306 	 */
307 	hsmp_pdev->num_sockets = amd_num_nodes();
308 	if (hsmp_pdev->num_sockets == 0 || hsmp_pdev->num_sockets > MAX_AMD_NUM_NODES)
309 		return ret;
310 
311 	ret = platform_driver_register(&amd_hsmp_driver);
312 	if (ret)
313 		return ret;
314 
315 	ret = hsmp_plat_dev_register();
316 	if (ret)
317 		platform_driver_unregister(&amd_hsmp_driver);
318 
319 	return ret;
320 }
321 
322 static void __exit hsmp_plt_exit(void)
323 {
324 	platform_device_unregister(amd_hsmp_platdev);
325 	platform_driver_unregister(&amd_hsmp_driver);
326 }
327 
328 device_initcall(hsmp_plt_init);
329 module_exit(hsmp_plt_exit);
330 
331 MODULE_IMPORT_NS("AMD_HSMP");
332 MODULE_DESCRIPTION("AMD HSMP Platform Interface Driver");
333 MODULE_VERSION(DRIVER_VERSION);
334 MODULE_LICENSE("GPL");
335