diff options
Diffstat (limited to 'examples/performance-thread/common/arch/arm64/stack.h')
| -rw-r--r-- | examples/performance-thread/common/arch/arm64/stack.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/examples/performance-thread/common/arch/arm64/stack.h b/examples/performance-thread/common/arch/arm64/stack.h new file mode 100644 index 00000000..fa3b31e9 --- /dev/null +++ b/examples/performance-thread/common/arch/arm64/stack.h @@ -0,0 +1,84 @@ +/* + * BSD LICENSE + * + * Copyright (C) Cavium, Inc. 2017. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Cavium, Inc nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef STACK_H +#define STACK_H + +#ifdef __cplusplus +extern "C" { +#endif + +#include "lthread_int.h" + +/* + * Sets up the initial stack for the lthread. + */ +static inline void +arch_set_stack(struct lthread *lt, void *func) +{ + void **stack_top = (void *)((char *)(lt->stack) + lt->stack_size); + + /* + * Align stack_top to 16 bytes. Arm64 has the constraint that the + * stack pointer must always be quad-word aligned. + */ + stack_top = (void **)(((unsigned long)(stack_top)) & ~0xfUL); + + /* + * First Stack Frame + */ + stack_top[0] = NULL; + stack_top[-1] = NULL; + + /* + * Initialize the context + */ + lt->ctx.fp = &stack_top[-1]; + lt->ctx.sp = &stack_top[-2]; + + /* + * Here only the address of _lthread_exec is saved as the link + * register value. The argument to _lthread_exec i.e the address of + * the lthread struct is not saved. This is because the first + * argument to ctx_switch is the address of the new context, + * which also happens to be the address of required lthread struct. + * So while returning from ctx_switch into _thread_exec, parameter + * register x0 will always contain the required value. + */ + lt->ctx.lr = func; +} + +#ifdef __cplusplus +} +#endif + +#endif /* STACK_H_ */ |