xref: /illumos-gate/usr/src/uts/intel/os/arch_kdi.c (revision c61a1653a4d73dbc950dac7d96350fd6cb517486)
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 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  *
25  * Copyright 2018 Joyent, Inc.
26  */
27 
28 /*
29  * Kernel/Debugger Interface (KDI) routines.  Called during debugger under
30  * various system states (boot, while running, while the debugger has control).
31  * Functions intended for use while the debugger has control may not grab any
32  * locks or perform any functions that assume the availability of other system
33  * services.
34  */
35 
36 #include <sys/systm.h>
37 #include <sys/x86_archext.h>
38 #include <sys/kdi_impl.h>
39 #include <sys/smp_impldefs.h>
40 #include <sys/psm_types.h>
41 #include <sys/segments.h>
42 #include <sys/archsystm.h>
43 #include <sys/controlregs.h>
44 #include <sys/trap.h>
45 #include <sys/kobj.h>
46 #include <sys/kobj_impl.h>
47 #include <sys/clock_impl.h>
48 
49 static void
50 kdi_system_claim(void)
51 {
52 	lbolt_debug_entry();
53 
54 	psm_notifyf(PSM_DEBUG_ENTER);
55 }
56 
57 static void
58 kdi_system_release(void)
59 {
60 	psm_notifyf(PSM_DEBUG_EXIT);
61 
62 	lbolt_debug_return();
63 }
64 
65 static cpu_t *
66 kdi_gdt2cpu(uintptr_t gdtbase)
67 {
68 	cpu_t *cp = cpu_list;
69 
70 	if (cp == NULL)
71 		return (NULL);
72 
73 	do {
74 		if (gdtbase == (uintptr_t)cp->cpu_gdt)
75 			return (cp);
76 	} while ((cp = cp->cpu_next) != cpu_list);
77 
78 	return (NULL);
79 }
80 
81 #if defined(__amd64)
82 uintptr_t
83 kdi_gdt2gsbase(uintptr_t gdtbase)
84 {
85 	return ((uintptr_t)kdi_gdt2cpu(gdtbase));
86 }
87 #endif
88 
89 static uintptr_t
90 kdi_get_userlimit(void)
91 {
92 	return (_userlimit);
93 }
94 
95 static int
96 kdi_get_cpuinfo(uint_t *vendorp, uint_t *familyp, uint_t *modelp)
97 {
98 	desctbr_t gdtr;
99 	cpu_t *cpu;
100 
101 	/*
102 	 * CPU doesn't work until the GDT and gs/GSBASE have been set up.
103 	 * Boot-loaded kmdb will call us well before then, so we have to
104 	 * find the current cpu_t the hard way.
105 	 */
106 	rd_gdtr(&gdtr);
107 	if ((cpu = kdi_gdt2cpu(gdtr.dtr_base)) == NULL ||
108 	    !cpuid_checkpass(cpu, 1))
109 		return (EAGAIN); /* cpuid isn't done yet */
110 
111 	*vendorp = cpuid_getvendor(cpu);
112 	*familyp = cpuid_getfamily(cpu);
113 	*modelp = cpuid_getmodel(cpu);
114 
115 	return (0);
116 }
117 
118 void
119 kdi_idtr_set(gate_desc_t *idt, size_t limit)
120 {
121 	desctbr_t idtr;
122 
123 	/*
124 	 * This rare case could happen if we entered kmdb whilst still on the
125 	 * fake CPU set up by boot_kdi_tmpinit().  We're trying to restore the
126 	 * kernel's IDT that we saved on entry, but it was from the fake cpu_t
127 	 * rather than the real IDT (which is still boot's).  It's unpleasant,
128 	 * but we just encode knowledge that it's idt0 we want to restore.
129 	 */
130 	if (idt == NULL)
131 		idt = idt0;
132 
133 	CPU->cpu_m.mcpu_idt = idt;
134 	idtr.dtr_base = (uintptr_t)idt;
135 	idtr.dtr_limit = limit;
136 	kdi_idtr_write(&idtr);
137 }
138 
139 static void
140 kdi_plat_call(void (*platfn)(void))
141 {
142 	if (platfn != NULL)
143 		platfn();
144 }
145 
146 /*
147  * On Intel, most of these are shared between i86*, so this is really an
148  * arch_kdi_init().
149  */
150 void
151 mach_kdi_init(kdi_t *kdi)
152 {
153 	kdi->kdi_plat_call = kdi_plat_call;
154 	kdi->kdi_kmdb_enter = kmdb_enter;
155 	kdi->mkdi_activate = kdi_activate;
156 	kdi->mkdi_deactivate = kdi_deactivate;
157 	kdi->mkdi_idt_switch = kdi_idt_switch;
158 	kdi->mkdi_update_drreg = kdi_update_drreg;
159 	kdi->mkdi_get_userlimit = kdi_get_userlimit;
160 	kdi->mkdi_get_cpuinfo = kdi_get_cpuinfo;
161 	kdi->mkdi_stop_slaves = kdi_stop_slaves;
162 	kdi->mkdi_start_slaves = kdi_start_slaves;
163 	kdi->mkdi_slave_wait = kdi_slave_wait;
164 	kdi->mkdi_memrange_add = kdi_memrange_add;
165 	kdi->mkdi_reboot = kdi_reboot;
166 }
167 
168 void
169 plat_kdi_init(kdi_t *kdi)
170 {
171 	kdi->pkdi_system_claim = kdi_system_claim;
172 	kdi->pkdi_system_release = kdi_system_release;
173 }
174