1/*
2 * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * @OSF_COPYRIGHT@
30 */
31/*
32 * Mach Operating System
33 * Copyright (c) 1991,1990 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
49 *  School of Computer Science
50 *  Carnegie Mellon University
51 *  Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56
57#include <mach_rt.h>
58#include <platforms.h>
59#include <mach_kdp.h>
60#include <mach_assert.h>
61
62#include <sys/errno.h>
63#include <i386/asm.h>
64#include <i386/cpuid.h>
65#include <i386/eflags.h>
66#include <i386/proc_reg.h>
67#include <i386/trap.h>
68#include <assym.s>
69#include <mach/exception_types.h>
70#include <config_dtrace.h>
71
72#define _ARCH_I386_ASM_HELP_H_          /* Prevent inclusion of user header */
73#include <mach/i386/syscall_sw.h>
74
75#include <i386/mp.h>
76
77/*
78 * Fault recovery.
79 */
80
81#ifdef	__MACHO__
82#define	RECOVERY_SECTION	.section	__VECTORS, __recover
83#else
84#define	RECOVERY_SECTION	.text
85#define	RECOVERY_SECTION	.text
86#endif
87
88#define	RECOVER_TABLE_START	\
89	.align 3		; \
90	.globl	EXT(recover_table) ;\
91LEXT(recover_table)		;\
92	.text
93
94#define	RECOVER(addr)		\
95	.align	3;		\
96	.quad	9f		;\
97	.quad	addr		;\
98	.text			;\
999:
100
101#define	RECOVER_TABLE_END		\
102	.align	3			;\
103	.globl	EXT(recover_table_end)	;\
104LEXT(recover_table_end)			;\
105	.text
106
107/*
108 * Allocate recovery and table.
109 */
110	RECOVERY_SECTION
111	RECOVER_TABLE_START
112
113/*
114 * int rdmsr_carefully(uint32_t msr, uint32_t *lo, uint32_t *hi)
115 */
116ENTRY(rdmsr_carefully)
117	movl	%edi, %ecx
118	movq	%rdx, %rdi
119	RECOVERY_SECTION
120	RECOVER(rdmsr_fail)
121	rdmsr
122	movl	%eax, (%rsi)
123	movl	%edx, (%rdi)
124	xorl	%eax, %eax
125	ret
126
127rdmsr_fail:
128	movq	$1, %rax
129	ret
130
131/*
132 * int rdmsr64_carefully(uint32_t msr, uint64_t *val);
133 */
134
135ENTRY(rdmsr64_carefully)
136	movl	%edi, %ecx
137	RECOVERY_SECTION
138	RECOVER(rdmsr64_carefully_fail)
139	rdmsr
140	movl	%eax, (%rsi)
141	movl	%edx, 4(%rsi)
142	xorl	%eax, %eax
143	ret
144rdmsr64_carefully_fail:
145	movl	$1, %eax
146	ret
147/*
148 * int wrmsr64_carefully(uint32_t msr, uint64_t val);
149 */
150
151ENTRY(wrmsr_carefully)
152	movl	%edi, %ecx
153	movl	%esi, %eax
154	shr	$32, %rsi
155	movl	%esi, %edx
156	RECOVERY_SECTION
157	RECOVER(wrmsr_fail)
158	wrmsr
159	xorl	%eax, %eax
160	ret
161wrmsr_fail:
162	movl	$1, %eax
163	ret
164
165.globl	EXT(thread_exception_return)
166.globl	EXT(thread_bootstrap_return)
167LEXT(thread_bootstrap_return)
168#if CONFIG_DTRACE
169	call EXT(dtrace_thread_bootstrap)
170#endif
171
172LEXT(thread_exception_return)
173	cli
174	xorl	%ecx, %ecx		/* don't check if we're in the PFZ */
175	jmp	EXT(return_from_trap)
176
177/*
178 * Copyin/out from user/kernel address space.
179 * rdi:	source address
180 * rsi:	destination address
181 * rdx:	byte count
182 */
183Entry(_bcopy)
184// TODO not pop regs; movq; think about 32 bit or 64 bit byte count
185	xchgq	%rdi, %rsi		/* source %rsi, dest %rdi */
186
187	cld				/* count up */
188	movl	%edx,%ecx		/* move by longwords first */
189	shrl	$3,%ecx
190	RECOVERY_SECTION
191	RECOVER(_bcopy_fail)
192	rep
193	movsq				/* move longwords */
194
195	movl	%edx,%ecx		/* now move remaining bytes */
196	andl	$7,%ecx
197	RECOVERY_SECTION
198	RECOVER(_bcopy_fail)
199	rep
200	movsb
201
202	xorl	%eax,%eax		/* return 0 for success */
203	ret				/* and return */
204
205_bcopy_fail:
206	movl	$(EFAULT),%eax		/* return error for failure */
207	ret
208
209Entry(pmap_safe_read)
210	RECOVERY_SECTION
211	RECOVER(_pmap_safe_read_fail)
212	movq	(%rdi), %rcx
213	mov	%rcx, (%rsi)
214	mov	$1, %eax
215	ret
216_pmap_safe_read_fail:
217	xor	%eax, %eax
218	ret
219
220
221
222/*
223 * Copyin string from user/kern address space.
224 * rdi:	source address
225 * rsi:	destination address
226 * rdx:	max byte count
227 * rcx:	actual byte count (OUT)
228 */
229Entry(_bcopystr)
230	pushq	%rdi
231	xchgq	%rdi, %rsi		/* source %rsi, dest %rdi */
232
233	xorl	%eax,%eax		/* set to 0 here so that high 24 bits */
234					/* are 0 for the cmpl against 0 */
2352:
236	RECOVERY_SECTION
237	RECOVER(_bcopystr_fail)		/* copy bytes... */
238	movb	(%rsi),%al
239	incq	%rsi
240	testq	%rdi,%rdi		/* if kernel address is ... */
241	jz	3f			/* not NULL */
242	movb	%al,(%rdi)		/* copy the byte */
243	incq	%rdi
2443:
245	testl	%eax,%eax		/* did we just stuff the 0-byte? */
246	jz	4f			/* yes, return 0 already in %eax */
247	decq	%rdx			/* decrement #bytes left in buffer */
248	jnz	2b			/* buffer not full, copy another byte */
249	movl	$(ENAMETOOLONG),%eax	/* buffer full, no \0: ENAMETOOLONG */
2504:
251	cmpq	$0,%rcx			/* get OUT len ptr */
252	jz	_bcopystr_ret		/* if null, just return */
253	subq	(%rsp),%rsi
254	movq	%rsi,(%rcx)		/* else set OUT arg to xfer len */
255	popq	%rdi			/* restore registers */
256_bcopystr_ret:
257	ret				/* and return */
258
259_bcopystr_fail:
260	popq	%rdi			/* restore registers */
261	movl	$(EFAULT),%eax		/* return error for failure */
262	ret
263
264/*
265 * Done with recovery table.
266 */
267	RECOVERY_SECTION
268	RECOVER_TABLE_END
269
270