mirror of
https://github.com/matrix-construct/construct
synced 2024-11-12 13:01:07 +01:00
70 lines
2.6 KiB
ArmAsm
70 lines
2.6 KiB
ArmAsm
// Matrix Construct
|
|
//
|
|
// Copyright (C) Matrix Construct Developers, Authors & Contributors
|
|
// Copyright (C) 2016-2019 Jason Volk <jason@zemos.net>
|
|
//
|
|
// Permission to use, copy, modify, and/or distribute this software for any
|
|
// purpose with or without fee is hereby granted, provided that the above
|
|
// copyright notice and this permission notice is present in all copies. The
|
|
// full license for this software is available in the LICENSE file.
|
|
|
|
//
|
|
// This context switch is smaller than asio's and fits in a single iline
|
|
//
|
|
|
|
#include <ircd/config.h>
|
|
#include <boost/version.hpp>
|
|
#if defined(__x86_64__) && defined(__ELF__)
|
|
|
|
.file "ctx_x86_64.S"
|
|
.globl jump_fcontext
|
|
|
|
// Sizes of additional items saved on context switch
|
|
.equiv x87_ctrl_sz, 0x04
|
|
.equiv mmx_ctrl_sz, 0x04
|
|
.equiv stack_prot_sz, 0x08
|
|
|
|
// Total size of all additional items
|
|
.if BOOST_VERSION >= 108100
|
|
.equiv alloc_sz, x87_ctrl_sz + mmx_ctrl_sz + stack_prot_sz
|
|
.else
|
|
.equiv alloc_sz, x87_ctrl_sz + mmx_ctrl_sz
|
|
.endif
|
|
|
|
.text
|
|
.type jump_fcontext, @function
|
|
|
|
.align 16
|
|
// returns struct transfer_t { void *fctx, *data; };
|
|
// param DI = void *to
|
|
// param SI = void *vp
|
|
jump_fcontext:
|
|
push %rbp // store rbp 0x30
|
|
push %rbx // store rbx 0x28
|
|
push %r15 // store r15 0x20
|
|
push %r14 // store r14 0x18
|
|
push %r13 // store r13 0x10
|
|
push %r12 // store r12 0x08
|
|
subq $alloc_sz, %rsp // additional allocation
|
|
fnstcw 0x04(%rsp) // store x87 control-word
|
|
stmxcsr 0x00(%rsp) // store MMX control- and status-word
|
|
xchgq %rsp, %rdi // swap stack
|
|
movq %rsi, %rdx // store transfer_t.data (retval)
|
|
movq %rdi, %rax // store transfer_t.fctx (retval)
|
|
ldmxcsr 0x00(%rsp) // load MMX control- and status-word
|
|
fldcw 0x04(%rsp) // load x87 control-word
|
|
addq $alloc_sz, %rsp // free allocation
|
|
pop %r12 // load r12 <-- LLd miss
|
|
pop %r13 // load r13
|
|
pop %r14 // load r14
|
|
pop %r15 // load r15
|
|
pop %rbx // load rbx
|
|
pop %rbp // load rbp <-- LLd miss
|
|
retq // enter context
|
|
|
|
// mark the size of jump_fcontext
|
|
.size jump_fcontext, .-jump_fcontext
|
|
|
|
// Mark that we don't need executable stack.
|
|
.section .note.GNU-stack, "", %progbits
|
|
#endif
|