source: trunk/hal/generic/hal_context.h @ 296

Last change on this file since 296 was 296, checked in by alain, 4 years ago

Several modifs in the generic scheduler and in the hal_context to
fix the context switch mechanism.

File size: 7.6 KB
Line 
1/*
2 * hal_context.h - Generic Thread Context Access API definition.
3 *
4 * Author  Alain Greiner    (2016)
5 *
6 * Copyright (c) UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2.0 of the License.
13 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#ifndef  _HAL_CONTEXT_H_
25#define  _HAL_CONTEXT_H_
26
27//////////////////////////////////////////////////////////////////////////////////////////
28//        Generic Thread Context API definition (implementation in hal_context.c)
29//
30// A thread context is defined by the two (core specific) structures hal_cpu_context_t
31// and hal_fpu_context_t, defined in hal_context.c file, that are accessed with generic
32// void* pointers stored in the thread descriptor.
33// - the "hal_context_t" structure is used to store the CPU registers values that
34//   have not been saved in the kernel stack by the interrupt handler.
35// - the "hal_fpu_context_t" structure is used to save the FPU registers when required.
36//////////////////////////////////////////////////////////////////////////////////////////
37
38/**** Forward declarations ****/
39
40struct thread_s;
41
42/****************************************************************************************
43 * This function allocates, from the local cluster, the physical memory required for
44 * the thread CPU context, initialises it, and links the context to the thread.
45 ****************************************************************************************
46 * @ thread  : pointer on the thread descriptor.
47 * @ return 0 if success / return ENOMEM if error
48 ***************************************************************************************/
49error_t hal_cpu_context_create( struct thread_s * thread );
50
51/****************************************************************************************
52 * This function allocates, from the local cluster, the physical memory required for
53 * a thread CPU context, initialises it from values contained in "src" thread context,
54 * and links the context to the "dst" thread.
55 ****************************************************************************************
56 * @ dst  : pointer on the destination thread descriptor.
57 * @ src  : pointer on the source thread descriptor.
58 * @ return 0 if success / return ENOMEM if error
59 ***************************************************************************************/
60error_t hal_cpu_context_copy( struct thread_s * dst,
61                              struct thread_s * src );
62
63/****************************************************************************************
64 * This function releases the physical memory allocated for a thread CPU context.
65 ****************************************************************************************
66 * @ thread  : pointer on the thread descriptor.
67 ***************************************************************************************/
68void hal_cpu_context_destroy( struct thread_s * thread );
69
70/****************************************************************************************
71 * This function saves in the thread context the CPU registers values that must be
72 * saved at context switch.
73 ****************************************************************************************
74 * @ ctx     : pointer on cpu context.
75 ***************************************************************************************/
76void hal_cpu_context_save( void * ctx );
77
78/****************************************************************************************
79 * This function restores from the thread context the CPU registers values that must
80 * be restored at context switch.
81 ****************************************************************************************
82 * @ ctx     : pointer on cpu context.
83 ***************************************************************************************/
84void hal_cpu_context_restore( void * ctx );
85
86/****************************************************************************************
87 * This function loads the relevant CPU registers from values contained in
88 * the thread context. It should be called for a thread that has not been executed yet.
89 * It reset the loadable flag in thread descriptor.
90 ****************************************************************************************
91 * @ thread  : pointer on the thread descriptor.
92 ***************************************************************************************/
93void hal_cpu_context_load( struct thread_s * thread );
94
95
96/****************************************************************************************
97 * This function allocates, from the local cluster, the physical memory required for
98 * the thread FPU context, and initialises the thread pointer.
99 ****************************************************************************************
100 * @ thread  : pointer on the thread descriptor.
101 * @ return 0 if success / return ENOMEM if error
102 ***************************************************************************************/
103error_t hal_fpu_context_create( struct thread_s * thread );
104
105/****************************************************************************************
106 * This function allocates, from the local cluster, the physical memory required for
107 * a thread FPU context, initialises it from values contained in "src" thread context,
108 * and link the context to the "dst" thread.
109 ****************************************************************************************
110 * @ dst  : pointer on the destination thread descriptor.
111 * @ src  : pointer on the source thread descriptor.
112 * @ return 0 if success / return ENOMEM if error
113 ***************************************************************************************/
114error_t hal_fpu_context_copy( struct thread_s * dst,
115                           struct thread_s * src );
116
117/****************************************************************************************
118 * This function releases the physical memory allocated for a FPU context.
119 ****************************************************************************************
120 * @ thread  : pointer on the thread descriptor.
121 ***************************************************************************************/
122void hal_fpu_context_destroy( struct thread_s * thread );
123
124/****************************************************************************************
125 * This function saves in the thread uzone the FPU registers values.
126 ****************************************************************************************
127 * @ thread  : pointer on the thread descriptor.
128 ***************************************************************************************/
129void hal_fpu_context_save( struct thread_s * thread );
130
131/****************************************************************************************
132 * This function restores from the thread uzone the FPU registers values.
133 ****************************************************************************************
134 * @ thread  : pointer on the thread descriptor.
135 ***************************************************************************************/
136void hal_fpu_context_restore( struct thread_s * thread );
137
138#endif  /* _HAL_CONTEXT_H_ */
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