xref: /freebsd/sys/amd64/amd64/initcpu.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
1 /*-
2  * Copyright (c) KATO Takenori, 1997, 1998.
3  *
4  * All rights reserved.  Unpublished rights reserved under the copyright
5  * laws of Japan.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer as
13  *    the first lines of this file unmodified.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include "opt_cpu.h"
34 
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/pcpu.h>
38 #include <sys/systm.h>
39 #include <sys/sysctl.h>
40 
41 #include <machine/cputypes.h>
42 #include <machine/md_var.h>
43 #include <machine/specialreg.h>
44 
45 #include <vm/vm.h>
46 #include <vm/pmap.h>
47 
48 static int	hw_instruction_sse;
49 SYSCTL_INT(_hw, OID_AUTO, instruction_sse, CTLFLAG_RD,
50     &hw_instruction_sse, 0, "SIMD/MMX2 instructions available in CPU");
51 /*
52  * -1: automatic (default)
53  *  0: keep enable CLFLUSH
54  *  1: force disable CLFLUSH
55  */
56 static int	hw_clflush_disable = -1;
57 
58 int	cpu;			/* Are we 386, 386sx, 486, etc? */
59 u_int	cpu_feature;		/* Feature flags */
60 u_int	cpu_feature2;		/* Feature flags */
61 u_int	amd_feature;		/* AMD feature flags */
62 u_int	amd_feature2;		/* AMD feature flags */
63 u_int	amd_pminfo;		/* AMD advanced power management info */
64 u_int	via_feature_rng;	/* VIA RNG features */
65 u_int	via_feature_xcrypt;	/* VIA ACE features */
66 u_int	cpu_high;		/* Highest arg to CPUID */
67 u_int	cpu_exthigh;		/* Highest arg to extended CPUID */
68 u_int	cpu_id;			/* Stepping ID */
69 u_int	cpu_procinfo;		/* HyperThreading Info / Brand Index / CLFUSH */
70 u_int	cpu_procinfo2;		/* Multicore info */
71 char	cpu_vendor[20];		/* CPU Origin code */
72 u_int	cpu_vendor_id;		/* CPU vendor ID */
73 u_int	cpu_fxsr;		/* SSE enabled */
74 u_int	cpu_mxcsr_mask;		/* Valid bits in mxcsr */
75 u_int	cpu_clflush_line_size = 32;
76 u_int	cpu_stdext_feature;
77 u_int	cpu_max_ext_state_size;
78 u_int	cpu_mon_mwait_flags;	/* MONITOR/MWAIT flags (CPUID.05H.ECX) */
79 u_int	cpu_mon_min_size;	/* MONITOR minimum range size, bytes */
80 u_int	cpu_mon_max_size;	/* MONITOR minimum range size, bytes */
81 
82 SYSCTL_UINT(_hw, OID_AUTO, via_feature_rng, CTLFLAG_RD,
83 	&via_feature_rng, 0, "VIA RNG feature available in CPU");
84 SYSCTL_UINT(_hw, OID_AUTO, via_feature_xcrypt, CTLFLAG_RD,
85 	&via_feature_xcrypt, 0, "VIA xcrypt feature available in CPU");
86 
87 static void
88 init_amd(void)
89 {
90 
91 	/*
92 	 * Work around Erratum 721 for Family 10h and 12h processors.
93 	 * These processors may incorrectly update the stack pointer
94 	 * after a long series of push and/or near-call instructions,
95 	 * or a long series of pop and/or near-return instructions.
96 	 *
97 	 * http://support.amd.com/us/Processor_TechDocs/41322_10h_Rev_Gd.pdf
98 	 * http://support.amd.com/us/Processor_TechDocs/44739_12h_Rev_Gd.pdf
99 	 *
100 	 * Hypervisors do not provide access to the errata MSR,
101 	 * causing #GP exception on attempt to apply the errata.  The
102 	 * MSR write shall be done on host and persist globally
103 	 * anyway, so do not try to do it when under virtualization.
104 	 */
105 	switch (CPUID_TO_FAMILY(cpu_id)) {
106 	case 0x10:
107 	case 0x12:
108 		if ((cpu_feature2 & CPUID2_HV) == 0)
109 			wrmsr(0xc0011029, rdmsr(0xc0011029) | 1);
110 		break;
111 	}
112 }
113 
114 /*
115  * Initialize special VIA features
116  */
117 static void
118 init_via(void)
119 {
120 	u_int regs[4], val;
121 
122 	/*
123 	 * Check extended CPUID for PadLock features.
124 	 *
125 	 * http://www.via.com.tw/en/downloads/whitepapers/initiatives/padlock/programming_guide.pdf
126 	 */
127 	do_cpuid(0xc0000000, regs);
128 	if (regs[0] >= 0xc0000001) {
129 		do_cpuid(0xc0000001, regs);
130 		val = regs[3];
131 	} else
132 		return;
133 
134 	/* Enable RNG if present. */
135 	if ((val & VIA_CPUID_HAS_RNG) != 0) {
136 		via_feature_rng = VIA_HAS_RNG;
137 		wrmsr(0x110B, rdmsr(0x110B) | VIA_CPUID_DO_RNG);
138 	}
139 
140 	/* Enable PadLock if present. */
141 	if ((val & VIA_CPUID_HAS_ACE) != 0)
142 		via_feature_xcrypt |= VIA_HAS_AES;
143 	if ((val & VIA_CPUID_HAS_ACE2) != 0)
144 		via_feature_xcrypt |= VIA_HAS_AESCTR;
145 	if ((val & VIA_CPUID_HAS_PHE) != 0)
146 		via_feature_xcrypt |= VIA_HAS_SHA;
147 	if ((val & VIA_CPUID_HAS_PMM) != 0)
148 		via_feature_xcrypt |= VIA_HAS_MM;
149 	if (via_feature_xcrypt != 0)
150 		wrmsr(0x1107, rdmsr(0x1107) | (1 << 28));
151 }
152 
153 /*
154  * Initialize CPU control registers
155  */
156 void
157 initializecpu(void)
158 {
159 	uint64_t msr;
160 	uint32_t cr4;
161 
162 	cr4 = rcr4();
163 	if ((cpu_feature & CPUID_XMM) && (cpu_feature & CPUID_FXSR)) {
164 		cr4 |= CR4_FXSR | CR4_XMM;
165 		cpu_fxsr = hw_instruction_sse = 1;
166 	}
167 	if (cpu_stdext_feature & CPUID_STDEXT_FSGSBASE)
168 		cr4 |= CR4_FSGSBASE;
169 
170 	/*
171 	 * Postpone enabling the SMEP on the boot CPU until the page
172 	 * tables are switched from the boot loader identity mapping
173 	 * to the kernel tables.  The boot loader enables the U bit in
174 	 * its tables.
175 	 */
176 	if (!IS_BSP() && (cpu_stdext_feature & CPUID_STDEXT_SMEP))
177 		cr4 |= CR4_SMEP;
178 	load_cr4(cr4);
179 	if ((amd_feature & AMDID_NX) != 0) {
180 		msr = rdmsr(MSR_EFER) | EFER_NXE;
181 		wrmsr(MSR_EFER, msr);
182 		pg_nx = PG_NX;
183 	}
184 	switch (cpu_vendor_id) {
185 	case CPU_VENDOR_AMD:
186 		init_amd();
187 		break;
188 	case CPU_VENDOR_CENTAUR:
189 		init_via();
190 		break;
191 	}
192 }
193 
194 void
195 initializecpucache(void)
196 {
197 
198 	/*
199 	 * CPUID with %eax = 1, %ebx returns
200 	 * Bits 15-8: CLFLUSH line size
201 	 * 	(Value * 8 = cache line size in bytes)
202 	 */
203 	if ((cpu_feature & CPUID_CLFSH) != 0)
204 		cpu_clflush_line_size = ((cpu_procinfo >> 8) & 0xff) * 8;
205 	/*
206 	 * XXXKIB: (temporary) hack to work around traps generated
207 	 * when CLFLUSHing APIC register window under virtualization
208 	 * environments.  These environments tend to disable the
209 	 * CPUID_SS feature even though the native CPU supports it.
210 	 */
211 	TUNABLE_INT_FETCH("hw.clflush_disable", &hw_clflush_disable);
212 	if (vm_guest != VM_GUEST_NO && hw_clflush_disable == -1)
213 		cpu_feature &= ~CPUID_CLFSH;
214 	/*
215 	 * Allow to disable CLFLUSH feature manually by
216 	 * hw.clflush_disable tunable.
217 	 */
218 	if (hw_clflush_disable == 1)
219 		cpu_feature &= ~CPUID_CLFSH;
220 }
221