xref: /illumos-gate/usr/src/uts/common/io/cpuid_drv.c (revision 42b53e0fbc5c05289c3d334bb864b784fafe5ce4)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 /*
25  * Copyright 2019 Joyent, Inc.
26  * Copyright 2022 Oxide Computer Co.
27  */
28 
29 
30 #include <sys/types.h>
31 #include <sys/file.h>
32 #include <sys/errno.h>
33 #include <sys/open.h>
34 #include <sys/cred.h>
35 #include <sys/conf.h>
36 #include <sys/stat.h>
37 #include <sys/processor.h>
38 #include <sys/cpuvar.h>
39 #include <sys/kmem.h>
40 #include <sys/modctl.h>
41 #include <sys/ddi.h>
42 #include <sys/sunddi.h>
43 #include <sys/policy.h>
44 
45 #include <sys/auxv.h>
46 #include <sys/cpuid_drv.h>
47 #include <sys/systeminfo.h>
48 
49 #if defined(__x86)
50 #include <sys/x86_archext.h>
51 #endif
52 
53 static dev_info_t *cpuid_devi;
54 
55 /*ARGSUSED*/
56 static int
57 cpuid_getinfo(dev_info_t *devi, ddi_info_cmd_t cmd, void *arg, void **result)
58 {
59 	switch (cmd) {
60 	case DDI_INFO_DEVT2DEVINFO:
61 	case DDI_INFO_DEVT2INSTANCE:
62 		break;
63 	default:
64 		return (DDI_FAILURE);
65 	}
66 
67 	switch (getminor((dev_t)arg)) {
68 	case CPUID_SELF_CPUID_MINOR:
69 		break;
70 	default:
71 		return (DDI_FAILURE);
72 	}
73 
74 	if (cmd == DDI_INFO_DEVT2INSTANCE)
75 		*result = 0;
76 	else
77 		*result = cpuid_devi;
78 	return (DDI_SUCCESS);
79 }
80 
81 static int
82 cpuid_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
83 {
84 	if (cmd != DDI_ATTACH)
85 		return (DDI_FAILURE);
86 	cpuid_devi = devi;
87 
88 	return (ddi_create_minor_node(devi, CPUID_DRIVER_SELF_NODE, S_IFCHR,
89 	    CPUID_SELF_CPUID_MINOR, DDI_PSEUDO, 0));
90 }
91 
92 static int
93 cpuid_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
94 {
95 	if (cmd != DDI_DETACH)
96 		return (DDI_FAILURE);
97 	ddi_remove_minor_node(devi, NULL);
98 	cpuid_devi = NULL;
99 	return (DDI_SUCCESS);
100 }
101 
102 /*ARGSUSED1*/
103 static int
104 cpuid_open(dev_t *dev, int flag, int otyp, cred_t *cr)
105 {
106 	return (getminor(*dev) == CPUID_SELF_CPUID_MINOR ? 0 : ENXIO);
107 }
108 
109 #if defined(_HAVE_CPUID_INSN)
110 
111 /*ARGSUSED*/
112 static int
113 cpuid_read(dev_t dev, uio_t *uio, cred_t *cr)
114 {
115 	struct cpuid_regs crs;
116 	int error = 0;
117 
118 	ASSERT(is_x86_feature(x86_featureset, X86FSET_CPUID));
119 
120 	if (uio->uio_resid & (sizeof (crs) - 1))
121 		return (EINVAL);
122 
123 	while (uio->uio_resid > 0) {
124 		u_offset_t uoff;
125 
126 		if ((uoff = (u_offset_t)uio->uio_loffset) > UINT_MAX) {
127 			error = EINVAL;
128 			break;
129 		}
130 
131 		crs.cp_eax = (uint32_t)uoff;
132 		crs.cp_ebx = crs.cp_ecx = crs.cp_edx = 0;
133 		(void) cpuid_insn(NULL, &crs);
134 
135 		if ((error = uiomove(&crs, sizeof (crs), UIO_READ, uio)) != 0)
136 			break;
137 		uio->uio_loffset = uoff + 1;
138 	}
139 
140 	return (error);
141 }
142 
143 #else
144 
145 #define	cpuid_read	nodev
146 
147 #endif	/* _HAVE_CPUID_INSN */
148 
149 /*ARGSUSED*/
150 static int
151 cpuid_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *cr, int *rval)
152 {
153 	char areq[16];
154 	void *ustr;
155 
156 	switch (cmd) {
157 	case CPUID_GET_HWCAP: {
158 		STRUCT_DECL(cpuid_get_hwcap, h);
159 
160 		STRUCT_INIT(h, mode);
161 		if (ddi_copyin((void *)arg,
162 		    STRUCT_BUF(h), STRUCT_SIZE(h), mode))
163 			return (EFAULT);
164 		if ((ustr = STRUCT_FGETP(h, cgh_archname)) != NULL &&
165 		    copyinstr(ustr, areq, sizeof (areq), NULL) != 0)
166 			return (EFAULT);
167 		areq[sizeof (areq) - 1] = '\0';
168 
169 		if (strcmp(areq, architecture) == 0) {
170 			STRUCT_FSET(h, cgh_hwcap[0], auxv_hwcap);
171 			STRUCT_FSET(h, cgh_hwcap[1], auxv_hwcap_2);
172 			STRUCT_FSET(h, cgh_hwcap[2], auxv_hwcap_3);
173 #if defined(_SYSCALL32_IMPL)
174 		} else if (strcmp(areq, architecture_32) == 0) {
175 			STRUCT_FSET(h, cgh_hwcap[0], auxv_hwcap32);
176 			STRUCT_FSET(h, cgh_hwcap[1], auxv_hwcap32_2);
177 			STRUCT_FSET(h, cgh_hwcap[2], auxv_hwcap32_3);
178 #endif
179 		} else {
180 			STRUCT_FSET(h, cgh_hwcap[0], 0);
181 			STRUCT_FSET(h, cgh_hwcap[1], 0);
182 			STRUCT_FSET(h, cgh_hwcap[2], 0);
183 		}
184 		if (ddi_copyout(STRUCT_BUF(h),
185 		    (void *)arg, STRUCT_SIZE(h), mode))
186 			return (EFAULT);
187 		return (0);
188 	}
189 
190 #ifdef __x86
191 	case CPUID_RDMSR: {
192 		struct cpuid_rdmsr crm = { 0, };
193 		label_t label;
194 
195 		if (secpolicy_sys_config(cr, B_FALSE) != 0)
196 			return (EPERM);
197 
198 		if (ddi_copyin((void *)arg, &crm, sizeof (crm), mode))
199 			return (EFAULT);
200 
201 		kpreempt_disable();
202 
203 		if (on_fault(&label)) {
204 			kpreempt_enable();
205 			return (ENOENT);
206 		}
207 
208 		crm.cr_msr_val = rdmsr(crm.cr_msr_nr);
209 
210 		no_fault();
211 		kpreempt_enable();
212 
213 		if (ddi_copyout(&crm, (void *)arg, sizeof (crm), mode))
214 			return (EFAULT);
215 		return (0);
216 	}
217 #endif
218 
219 	default:
220 		return (ENOTTY);
221 	}
222 }
223 
224 static struct cb_ops cpuid_cb_ops = {
225 	cpuid_open,
226 	nulldev,	/* close */
227 	nodev,		/* strategy */
228 	nodev,		/* print */
229 	nodev,		/* dump */
230 	cpuid_read,
231 	nodev,		/* write */
232 	cpuid_ioctl,
233 	nodev,		/* devmap */
234 	nodev,		/* mmap */
235 	nodev,		/* segmap */
236 	nochpoll,	/* poll */
237 	ddi_prop_op,
238 	NULL,
239 	D_64BIT | D_NEW | D_MP
240 };
241 
242 static struct dev_ops cpuid_dv_ops = {
243 	DEVO_REV,
244 	0,
245 	cpuid_getinfo,
246 	nulldev,	/* identify */
247 	nulldev,	/* probe */
248 	cpuid_attach,
249 	cpuid_detach,
250 	nodev,		/* reset */
251 	&cpuid_cb_ops,
252 	(struct bus_ops *)0,
253 	NULL,
254 	ddi_quiesce_not_needed,		/* quiesce */
255 };
256 
257 static struct modldrv modldrv = {
258 	&mod_driverops,
259 	"cpuid driver",
260 	&cpuid_dv_ops
261 };
262 
263 static struct modlinkage modl = {
264 	MODREV_1,
265 	&modldrv
266 };
267 
268 int
269 _init(void)
270 {
271 	return (mod_install(&modl));
272 }
273 
274 int
275 _fini(void)
276 {
277 	return (mod_remove(&modl));
278 }
279 
280 int
281 _info(struct modinfo *modinfo)
282 {
283 	return (mod_info(&modl, modinfo));
284 }
285