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 #define DRIVER_VERSION		"2.3"
28 
29 /*
30  * To access specific HSMP mailbox register, s/w writes the SMN address of HSMP mailbox
31  * register into the SMN_INDEX register, and reads/writes the SMN_DATA reg.
32  * Below are required SMN address for HSMP Mailbox register offsets in SMU address space
33  */
34 #define SMN_HSMP_BASE		0x3B00000
35 #define SMN_HSMP_MSG_ID		0x0010534
36 #define SMN_HSMP_MSG_ID_F1A_M0H	0x0010934
37 #define SMN_HSMP_MSG_RESP	0x0010980
38 #define SMN_HSMP_MSG_DATA	0x00109E0
39 
40 static struct hsmp_plat_device *hsmp_pdev;
41 
amd_hsmp_pci_rdwr(struct hsmp_socket * sock,u32 offset,u32 * value,bool write)42 static int amd_hsmp_pci_rdwr(struct hsmp_socket *sock, u32 offset,
43 			     u32 *value, bool write)
44 {
45 	return amd_smn_hsmp_rdwr(sock->sock_ind, sock->mbinfo.base_addr + offset, value, write);
46 }
47 
hsmp_metric_tbl_plat_read(struct file * filp,struct kobject * kobj,const struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)48 static ssize_t hsmp_metric_tbl_plat_read(struct file *filp, struct kobject *kobj,
49 					 const struct bin_attribute *bin_attr, char *buf,
50 					 loff_t off, size_t count)
51 {
52 	struct hsmp_socket *sock;
53 	u16 sock_ind;
54 
55 	sock_ind = (uintptr_t)bin_attr->private;
56 	if (sock_ind >= hsmp_pdev->num_sockets)
57 		return -EINVAL;
58 
59 	sock = &hsmp_pdev->sock[sock_ind];
60 
61 	return hsmp_metric_tbl_read(sock, buf, count);
62 }
63 
hsmp_is_sock_attr_visible(struct kobject * kobj,const struct bin_attribute * battr,int id)64 static umode_t hsmp_is_sock_attr_visible(struct kobject *kobj,
65 					 const struct bin_attribute *battr, int id)
66 {
67 	u16 sock_ind;
68 
69 	sock_ind = (uintptr_t)battr->private;
70 
71 	if (id == 0 && sock_ind >= hsmp_pdev->num_sockets)
72 		return SYSFS_GROUP_INVISIBLE;
73 
74 	if (hsmp_pdev->proto_ver == HSMP_PROTO_VER6)
75 		return battr->attr.mode;
76 
77 	return 0;
78 }
79 
80 /*
81  * AMD supports maximum of 8 sockets in a system.
82  * Static array of 8 + 1(for NULL) elements is created below
83  * to create sysfs groups for sockets.
84  * is_bin_visible function is used to show / hide the necessary groups.
85  *
86  * Validate the maximum number against MAX_AMD_NUM_NODES. If this changes,
87  * then the attributes and groups below must be adjusted.
88  */
89 static_assert(MAX_AMD_NUM_NODES == 8);
90 
91 #define HSMP_BIN_ATTR(index, _list)					\
92 static const struct bin_attribute attr##index = {			\
93 	.attr = { .name = HSMP_METRICS_TABLE_NAME, .mode = 0444},	\
94 	.private = (void *)index,					\
95 	.read_new = hsmp_metric_tbl_plat_read,				\
96 	.size = sizeof(struct hsmp_metric_table),			\
97 };									\
98 static const struct bin_attribute _list[] = {				\
99 	&attr##index,							\
100 	NULL								\
101 }
102 
103 HSMP_BIN_ATTR(0, *sock0_attr_list);
104 HSMP_BIN_ATTR(1, *sock1_attr_list);
105 HSMP_BIN_ATTR(2, *sock2_attr_list);
106 HSMP_BIN_ATTR(3, *sock3_attr_list);
107 HSMP_BIN_ATTR(4, *sock4_attr_list);
108 HSMP_BIN_ATTR(5, *sock5_attr_list);
109 HSMP_BIN_ATTR(6, *sock6_attr_list);
110 HSMP_BIN_ATTR(7, *sock7_attr_list);
111 
112 #define HSMP_BIN_ATTR_GRP(index, _list, _name)			\
113 static const struct attribute_group sock##index##_attr_grp = {	\
114 	.bin_attrs_new = _list,					\
115 	.is_bin_visible = hsmp_is_sock_attr_visible,		\
116 	.name = #_name,						\
117 }
118 
119 HSMP_BIN_ATTR_GRP(0, sock0_attr_list, socket0);
120 HSMP_BIN_ATTR_GRP(1, sock1_attr_list, socket1);
121 HSMP_BIN_ATTR_GRP(2, sock2_attr_list, socket2);
122 HSMP_BIN_ATTR_GRP(3, sock3_attr_list, socket3);
123 HSMP_BIN_ATTR_GRP(4, sock4_attr_list, socket4);
124 HSMP_BIN_ATTR_GRP(5, sock5_attr_list, socket5);
125 HSMP_BIN_ATTR_GRP(6, sock6_attr_list, socket6);
126 HSMP_BIN_ATTR_GRP(7, sock7_attr_list, socket7);
127 
128 static const struct attribute_group *hsmp_groups[] = {
129 	&sock0_attr_grp,
130 	&sock1_attr_grp,
131 	&sock2_attr_grp,
132 	&sock3_attr_grp,
133 	&sock4_attr_grp,
134 	&sock5_attr_grp,
135 	&sock6_attr_grp,
136 	&sock7_attr_grp,
137 	NULL
138 };
139 
is_f1a_m0h(void)140 static inline bool is_f1a_m0h(void)
141 {
142 	if (boot_cpu_data.x86 == 0x1A && boot_cpu_data.x86_model <= 0x0F)
143 		return true;
144 
145 	return false;
146 }
147 
init_platform_device(struct device * dev)148 static int init_platform_device(struct device *dev)
149 {
150 	struct hsmp_socket *sock;
151 	int ret, i;
152 
153 	for (i = 0; i < hsmp_pdev->num_sockets; i++) {
154 		sock = &hsmp_pdev->sock[i];
155 		sock->sock_ind			= i;
156 		sock->dev			= dev;
157 		sock->mbinfo.base_addr		= SMN_HSMP_BASE;
158 		sock->amd_hsmp_rdwr		= amd_hsmp_pci_rdwr;
159 
160 		/*
161 		 * This is a transitional change from non-ACPI to ACPI, only
162 		 * family 0x1A, model 0x00 platform is supported for both ACPI and non-ACPI.
163 		 */
164 		if (is_f1a_m0h())
165 			sock->mbinfo.msg_id_off	= SMN_HSMP_MSG_ID_F1A_M0H;
166 		else
167 			sock->mbinfo.msg_id_off	= SMN_HSMP_MSG_ID;
168 
169 		sock->mbinfo.msg_resp_off	= SMN_HSMP_MSG_RESP;
170 		sock->mbinfo.msg_arg_off	= SMN_HSMP_MSG_DATA;
171 		sema_init(&sock->hsmp_sem, 1);
172 
173 		/* Test the hsmp interface on each socket */
174 		ret = hsmp_test(i, 0xDEADBEEF);
175 		if (ret) {
176 			dev_err(dev, "HSMP test message failed on Fam:%x model:%x\n",
177 				boot_cpu_data.x86, boot_cpu_data.x86_model);
178 			dev_err(dev, "Is HSMP disabled in BIOS ?\n");
179 			return ret;
180 		}
181 
182 		ret = hsmp_cache_proto_ver(i);
183 		if (ret) {
184 			dev_err(dev, "Failed to read HSMP protocol version\n");
185 			return ret;
186 		}
187 
188 		if (hsmp_pdev->proto_ver == HSMP_PROTO_VER6) {
189 			ret = hsmp_get_tbl_dram_base(i);
190 			if (ret)
191 				dev_err(dev, "Failed to init metric table\n");
192 		}
193 	}
194 
195 	return 0;
196 }
197 
hsmp_pltdrv_probe(struct platform_device * pdev)198 static int hsmp_pltdrv_probe(struct platform_device *pdev)
199 {
200 	int ret;
201 
202 	hsmp_pdev->sock = devm_kcalloc(&pdev->dev, hsmp_pdev->num_sockets,
203 				       sizeof(*hsmp_pdev->sock),
204 				       GFP_KERNEL);
205 	if (!hsmp_pdev->sock)
206 		return -ENOMEM;
207 
208 	ret = init_platform_device(&pdev->dev);
209 	if (ret) {
210 		dev_err(&pdev->dev, "Failed to init HSMP mailbox\n");
211 		return ret;
212 	}
213 
214 	return hsmp_misc_register(&pdev->dev);
215 }
216 
hsmp_pltdrv_remove(struct platform_device * pdev)217 static void hsmp_pltdrv_remove(struct platform_device *pdev)
218 {
219 	hsmp_misc_deregister();
220 }
221 
222 static struct platform_driver amd_hsmp_driver = {
223 	.probe		= hsmp_pltdrv_probe,
224 	.remove		= hsmp_pltdrv_remove,
225 	.driver		= {
226 		.name	= DRIVER_NAME,
227 		.dev_groups = hsmp_groups,
228 	},
229 };
230 
231 static struct platform_device *amd_hsmp_platdev;
232 
hsmp_plat_dev_register(void)233 static int hsmp_plat_dev_register(void)
234 {
235 	int ret;
236 
237 	amd_hsmp_platdev = platform_device_alloc(DRIVER_NAME, PLATFORM_DEVID_NONE);
238 	if (!amd_hsmp_platdev)
239 		return -ENOMEM;
240 
241 	ret = platform_device_add(amd_hsmp_platdev);
242 	if (ret)
243 		platform_device_put(amd_hsmp_platdev);
244 
245 	return ret;
246 }
247 
248 /*
249  * This check is only needed for backward compatibility of previous platforms.
250  * All new platforms are expected to support ACPI based probing.
251  */
legacy_hsmp_support(void)252 static bool legacy_hsmp_support(void)
253 {
254 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
255 		return false;
256 
257 	switch (boot_cpu_data.x86) {
258 	case 0x19:
259 		switch (boot_cpu_data.x86_model) {
260 		case 0x00 ... 0x1F:
261 		case 0x30 ... 0x3F:
262 		case 0x90 ... 0x9F:
263 		case 0xA0 ... 0xAF:
264 			return true;
265 		default:
266 			return false;
267 		}
268 	case 0x1A:
269 		switch (boot_cpu_data.x86_model) {
270 		case 0x00 ... 0x0F:
271 			return true;
272 		default:
273 			return false;
274 		}
275 	default:
276 		return false;
277 	}
278 
279 	return false;
280 }
281 
hsmp_plt_init(void)282 static int __init hsmp_plt_init(void)
283 {
284 	int ret = -ENODEV;
285 
286 	if (!legacy_hsmp_support()) {
287 		pr_info("HSMP is not supported on Family:%x model:%x\n",
288 			boot_cpu_data.x86, boot_cpu_data.x86_model);
289 		return ret;
290 	}
291 
292 	if (acpi_dev_present(ACPI_HSMP_DEVICE_HID, NULL, -1))
293 		return -ENODEV;
294 
295 	hsmp_pdev = get_hsmp_pdev();
296 	if (!hsmp_pdev)
297 		return -ENOMEM;
298 
299 	/*
300 	 * amd_num_nodes() returns number of SMN/DF interfaces present in the system
301 	 * if we have N SMN/DF interfaces that ideally means N sockets
302 	 */
303 	hsmp_pdev->num_sockets = amd_num_nodes();
304 	if (hsmp_pdev->num_sockets == 0 || hsmp_pdev->num_sockets > MAX_AMD_NUM_NODES)
305 		return ret;
306 
307 	ret = platform_driver_register(&amd_hsmp_driver);
308 	if (ret)
309 		return ret;
310 
311 	ret = hsmp_plat_dev_register();
312 	if (ret)
313 		platform_driver_unregister(&amd_hsmp_driver);
314 
315 	return ret;
316 }
317 
hsmp_plt_exit(void)318 static void __exit hsmp_plt_exit(void)
319 {
320 	platform_device_unregister(amd_hsmp_platdev);
321 	platform_driver_unregister(&amd_hsmp_driver);
322 }
323 
324 device_initcall(hsmp_plt_init);
325 module_exit(hsmp_plt_exit);
326 
327 MODULE_IMPORT_NS("AMD_HSMP");
328 MODULE_DESCRIPTION("AMD HSMP Platform Interface Driver");
329 MODULE_VERSION(DRIVER_VERSION);
330 MODULE_LICENSE("GPL");
331