2 * Copyright (c) 2007 Matthew T. Emmerton <matt@gsicomp.on.ca>
4 * Copyright (c) 2007 Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Neither the name of the author nor the names of its contributors
13 * may be used to endorse or promote products derived from this software
14 * without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <machine/asm.h>
30 #include <cpu/specialreg.h>
31 #include <asmcontext.h>
34 * int get_mcontext(mcontext_t *mcp : rdi)
36 * Copy the caller's context into the mcontext, %rax excepted.
39 .set get_mcontext,_get_mcontext
41 movq $0,MC_ONSTACK(%rdi) /* MC_ONSTACK(%rdi) */
42 movq %rdi,MC_RDI(%rdi)
43 movq %rsi,MC_RSI(%rdi)
44 movq %rdx,MC_RDX(%rdi)
47 /* movq %rax,MC_RAX(%rdi) - not needed, replaced below */
48 movq %rbx,MC_RBX(%rdi)
49 /* movq %rcx,MC_RCX(%rdi) - not needed, scratch */
50 movq %rbp,MC_RBP(%rdi)
51 movq %r10,MC_R10(%rdi)
52 movq %r11,MC_R11(%rdi)
53 movq %r12,MC_R12(%rdi)
54 movq %r13,MC_R13(%rdi)
55 movq %r14,MC_R14(%rdi)
56 movq %r15,MC_R15(%rdi)
61 /* MC_RIP(%rdi) - see below */
63 movq $KUCSEL,MC_CS(%rdi)
67 /* MC_RSP(%rdi) - see below */
71 * FP registers are scratch, do not save or restore, but make
72 * sure the context can be restored by a signal handler (where
73 * they might not be) by properly initializing the FP control
76 movl $_MC_FPOWNED_NONE,MC_OWNEDFP(%rdi)
77 movl $_MC_FPFMT_NODEV,MC_FPFORMAT(%rdi)
79 movl $_MC_FPFMT_YMM,MC_FPFORMAT(%rdi)
82 movq $CPU_XFEATURE_X87 | CPU_XFEATURE_SSE | CPU_XFEATURE_YMM,%rax
88 * Saved stack pointer as if we had returned from this
91 movq %rsp,MC_RSP(%rdi)
100 * Saved instruction pointer as if we had returned from
104 movq %rdx,MC_RIP(%rdi)
107 * On restore as if procedure returned the value 1
114 movl $SIZEOF_MCONTEXT_T,MC_LEN(%rdi)
125 * int set_mcontext(mcontext_t *mcp)
127 * Load the register context, effectively switching to the
131 .set set_mcontext,_set_mcontext
134 * Restore FP regs (might be needed if the context was
135 * taken out of a signal context).
137 cmpl $_MC_FPFMT_NODEV,MC_FPFORMAT(%rdi)
140 movq $CPU_XFEATURE_X87 | CPU_XFEATURE_SSE | CPU_XFEATURE_YMM,%rax
142 xrstor MC_FPREGS(%rsi) /* hack assumes cpu supports this */
146 /* MC_ONSTACK(%rdi) */
147 /* MC_RDI(%rdi) - see below */
148 movq MC_RSI(%rdi),%rsi
149 movq MC_RDX(%rdi),%rdx
152 /* MC_RAX(%rdi) - see below */
153 movq MC_RBX(%rdi),%rbx
154 movq MC_RCX(%rdi),%rcx
155 movq MC_RBP(%rdi),%rbp
156 movq MC_R10(%rdi),%r10
157 movq MC_R11(%rdi),%r11
158 movq MC_R12(%rdi),%r12
159 movq MC_R13(%rdi),%r13
160 movq MC_R14(%rdi),%r14
161 movq MC_R15(%rdi),%r15
162 /* MC_TRAPNO(%rdi) */
166 /* MC_RIP(%rdi) - see below */
168 /* MC_RFLAGS(%rdi) - see below */
169 /* MC_RSP(%rdi) - see below */
173 * Load the new stack pointer
175 movq MC_RSP(%rdi),%rsp
178 * Push the return pc so we can 'ret' to it.
180 * Push the flags so we can restore them just prior to the retq
181 * (in case setcontext is called
184 * XXX this can cream stuff under the stack pointer, which should
185 * normally be ok but its a side effect I'd rather not have.
188 pushq MC_RFLAGS(%rdi)
191 * Finally rax and rdi
193 movq MC_RAX(%rdi),%rax
194 movq MC_RDI(%rdi),%rdi
199 .section .note.GNU-stack,"",%progbits