97 lines
3.8 KiB
C
97 lines
3.8 KiB
C
|
/* strtask.c - Intel nanokernel APIs to start a task */
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Copyright (c) 2010-2014 Wind River Systems, Inc.
|
||
|
|
*
|
||
|
|
* Redistribution and use in source and binary forms, with or without
|
||
|
|
* modification, are permitted provided that the following conditions are met:
|
||
|
|
*
|
||
|
|
* 1) Redistributions of source code must retain the above copyright notice,
|
||
|
|
* this list of conditions and the following disclaimer.
|
||
|
|
*
|
||
|
|
* 2) 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.
|
||
|
|
*
|
||
|
|
* 3) Neither the name of Wind River Systems 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 HOLDER 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
DESCRIPTION
|
||
|
|
Intel-specific parts of start_task(). Only FP functionality currently.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifdef CONFIG_MICROKERNEL
|
||
|
|
|
||
|
|
#include <start_task_arch.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* The following IA-32-specific task group is used for tasks that use SSE
|
||
|
|
* instructions. It is *not* formally reserved by SysGen for this purpose.
|
||
|
|
* See comments in nanocontext.c regarding the use of SSE_GROUP, and comments
|
||
|
|
* in task.h regarding task groups reserved by SysGen.
|
||
|
|
*
|
||
|
|
* This identifier corresponds to the first user-defined task group.
|
||
|
|
* It must be updated if any changes are made to the reserved groups.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#define SSE_GROUP 0x10
|
||
|
|
|
||
|
|
/*******************************************************************************
|
||
|
|
*
|
||
|
|
* _StartTaskArch - Intel-specifc parts of task initialization
|
||
|
|
*
|
||
|
|
* RETURNS: N/A
|
||
|
|
*/
|
||
|
|
|
||
|
|
void _StartTaskArch(
|
||
|
|
struct k_proc *X, /* ptr to task control block */
|
||
|
|
unsigned int *pOpt /* context options container */
|
||
|
|
)
|
||
|
|
{
|
||
|
|
/*
|
||
|
|
* The IA-32 nanokernel implementation uses the USE_FP bit in the
|
||
|
|
* tCCS->flags structure as a "dirty bit". The USE_FP flag bit will be
|
||
|
|
* set whenever a context uses any non-integer capability, whether it's
|
||
|
|
* just the x87 FPU capability, SSE instructions, or a combination of
|
||
|
|
* both. The USE_SSE flag bit will only be set if a context uses SSE
|
||
|
|
* instructions.
|
||
|
|
*
|
||
|
|
* However, callers of nanoFiberStart(), task_fiber_start(), or even
|
||
|
|
* _NewContext() don't need to follow the protocol used by the IA-32
|
||
|
|
* nanokernel w.r.t. managing the tCCS->flags field. If a context
|
||
|
|
* will be utilizing just the x87 FPU capability, then the USE_FP
|
||
|
|
* option bit is specified. If a context will be utilizing SSE
|
||
|
|
* instructions (and possibly x87 FPU capability), then only the
|
||
|
|
* USE_SSE option bit needs to be specified.
|
||
|
|
*
|
||
|
|
* Likewise, the placement of tasks into "groups" doesn't need to follow
|
||
|
|
* the protocol used by the IA-32 nanokernel w.r.t. managing the
|
||
|
|
* tCCS->flags field. If a task will utilize just the x87 FPU
|
||
|
|
*capability,
|
||
|
|
* then the task only needs to be placed in the FPU_GROUP group.
|
||
|
|
* If a task utilizes SSE instructions (and possibly x87 FPU
|
||
|
|
*capability),
|
||
|
|
* then the task only needs to be placed in the SSE_GROUP group.
|
||
|
|
*/
|
||
|
|
|
||
|
|
*pOpt |= (X->Group & SSE_GROUP) ? USE_SSE
|
||
|
|
: (X->Group & FPU_GROUP) ? USE_FP : 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* CONFIG_MICROKERNEL */
|