xref: /illumos-gate/usr/src/uts/common/io/cpuid_drv.c (revision 12596538)
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  */
27 
28 
29 #include <sys/types.h>
30 #include <sys/file.h>
31 #include <sys/errno.h>
32 #include <sys/open.h>
33 #include <sys/cred.h>
34 #include <sys/conf.h>
35 #include <sys/stat.h>
36 #include <sys/processor.h>
37 #include <sys/cpuvar.h>
38 #include <sys/kmem.h>
39 #include <sys/modctl.h>
40 #include <sys/ddi.h>
41 #include <sys/sunddi.h>
42 #include <sys/policy.h>
43 
44 #include <sys/auxv.h>
45 #include <sys/cpuid_drv.h>
46 #include <sys/systeminfo.h>
47 
48 #if defined(__x86)
49 #include <sys/x86_archext.h>
50 #endif
51 
52 static dev_info_t *cpuid_devi;
53 
54 /*ARGSUSED*/
55 static int
cpuid_getinfo(dev_info_t * devi,ddi_info_cmd_t cmd,void * arg,void ** result)56 cpuid_getinfo(dev_info_t *devi, ddi_info_cmd_t cmd, void *arg, void **result)
57 {
58 	switch (cmd) {
59 	case DDI_INFO_DEVT2DEVINFO:
60 	case DDI_INFO_DEVT2INSTANCE:
61 		break;
62 	default:
63 		return (DDI_FAILURE);
64 	}
65 
66 	switch (getminor((dev_t)arg)) {
67 	case CPUID_SELF_CPUID_MINOR:
68 		break;
69 	default:
70 		return (DDI_FAILURE);
71 	}
72 
73 	if (cmd == DDI_INFO_DEVT2INSTANCE)
74 		*result = 0;
75 	else
76 		*result = cpuid_devi;
77 	return (DDI_SUCCESS);
78 }
79 
80 static int
cpuid_attach(dev_info_t * devi,ddi_attach_cmd_t cmd)81 cpuid_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
82 {
83 	if (cmd != DDI_ATTACH)
84 		return (DDI_FAILURE);
85 	cpuid_devi = devi;
86 
87 	return (ddi_create_minor_node(devi, CPUID_DRIVER_SELF_NODE, S_IFCHR,
88 	    CPUID_SELF_CPUID_MINOR, DDI_PSEUDO, 0));
89 }
90 
91 static int
cpuid_detach(dev_info_t * devi,ddi_detach_cmd_t cmd)92 cpuid_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
93 {
94 	if (cmd != DDI_DETACH)
95 		return (DDI_FAILURE);
96 	ddi_remove_minor_node(devi, NULL);
97 	cpuid_devi = NULL;
98 	return (DDI_SUCCESS);
99 }
100 
101 /*ARGSUSED1*/
102 static int
cpuid_open(dev_t * dev,int flag,int otyp,cred_t * cr)103 cpuid_open(dev_t *dev, int flag, int otyp, cred_t *cr)
104 {
105 	return (getminor(*dev) == CPUID_SELF_CPUID_MINOR ? 0 : ENXIO);
106 }
107 
108 #if defined(_HAVE_CPUID_INSN)
109 
110 /*ARGSUSED*/
111 static int
cpuid_read(dev_t dev,uio_t * uio,cred_t * cr)112 cpuid_read(dev_t dev, uio_t *uio, cred_t *cr)
113 {
114 	struct cpuid_regs crs;
115 	int error = 0;
116 
117 	if (!is_x86_feature(x86_featureset, X86FSET_CPUID))
118 		return (ENXIO);
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
cpuid_ioctl(dev_t dev,int cmd,intptr_t arg,int mode,cred_t * cr,int * rval)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 #if defined(_SYSCALL32_IMPL)
173 		} else if (strcmp(areq, architecture_32) == 0) {
174 			STRUCT_FSET(h, cgh_hwcap[0], auxv_hwcap32);
175 			STRUCT_FSET(h, cgh_hwcap[1], auxv_hwcap32_2);
176 #endif
177 		} else {
178 			STRUCT_FSET(h, cgh_hwcap[0], 0);
179 			STRUCT_FSET(h, cgh_hwcap[1], 0);
180 		}
181 		if (ddi_copyout(STRUCT_BUF(h),
182 		    (void *)arg, STRUCT_SIZE(h), mode))
183 			return (EFAULT);
184 		return (0);
185 	}
186 
187 #ifdef __x86
188 	case CPUID_RDMSR: {
189 		struct cpuid_rdmsr crm = { 0, };
190 		label_t label;
191 
192 		if (secpolicy_sys_config(cr, B_FALSE) != 0)
193 			return (EPERM);
194 
195 		if (ddi_copyin((void *)arg, &crm, sizeof (crm), mode))
196 			return (EFAULT);
197 
198 		kpreempt_disable();
199 
200 		if (on_fault(&label)) {
201 			kpreempt_enable();
202 			return (ENOENT);
203 		}
204 
205 		crm.cr_msr_val = rdmsr(crm.cr_msr_nr);
206 
207 		no_fault();
208 		kpreempt_enable();
209 
210 		if (ddi_copyout(&crm, (void *)arg, sizeof (crm), mode))
211 			return (EFAULT);
212 		return (0);
213 	}
214 #endif
215 
216 	default:
217 		return (ENOTTY);
218 	}
219 }
220 
221 static struct cb_ops cpuid_cb_ops = {
222 	cpuid_open,
223 	nulldev,	/* close */
224 	nodev,		/* strategy */
225 	nodev,		/* print */
226 	nodev,		/* dump */
227 	cpuid_read,
228 	nodev,		/* write */
229 	cpuid_ioctl,
230 	nodev,		/* devmap */
231 	nodev,		/* mmap */
232 	nodev,		/* segmap */
233 	nochpoll,	/* poll */
234 	ddi_prop_op,
235 	NULL,
236 	D_64BIT | D_NEW | D_MP
237 };
238 
239 static struct dev_ops cpuid_dv_ops = {
240 	DEVO_REV,
241 	0,
242 	cpuid_getinfo,
243 	nulldev,	/* identify */
244 	nulldev,	/* probe */
245 	cpuid_attach,
246 	cpuid_detach,
247 	nodev,		/* reset */
248 	&cpuid_cb_ops,
249 	(struct bus_ops *)0,
250 	NULL,
251 	ddi_quiesce_not_needed,		/* quiesce */
252 };
253 
254 static struct modldrv modldrv = {
255 	&mod_driverops,
256 	"cpuid driver",
257 	&cpuid_dv_ops
258 };
259 
260 static struct modlinkage modl = {
261 	MODREV_1,
262 	&modldrv
263 };
264 
265 int
_init(void)266 _init(void)
267 {
268 	return (mod_install(&modl));
269 }
270 
271 int
_fini(void)272 _fini(void)
273 {
274 	return (mod_remove(&modl));
275 }
276 
277 int
_info(struct modinfo * modinfo)278 _info(struct modinfo *modinfo)
279 {
280 	return (mod_info(&modl, modinfo));
281 }
282