source: trunk/kernel/libk/remote_busylock.c @ 623

Last change on this file since 623 was 619, checked in by alain, 5 years ago

1) Fix a bug in KSH : after the "load" command,

the [ksh] prompt is now printed after completion
of the loaded application.

2) Fix a bug in vmm_handle_cow() : the copy-on-write

use now a hal_remote_memcpy() to replicate the page content.


File size: 4.9 KB
Line 
1/*
2 * remote_busylock.c - remote kernel busy-waiting lock implementation.
3 *
4 * Authors     Alain Greiner (2016,2017,2018)
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#include <kernel_config.h>
25#include <hal_kernel_types.h>
26#include <hal_irqmask.h>
27#include <hal_special.h>
28#include <hal_remote.h>
29#include <thread.h>
30#include <remote_busylock.h>
31
32//////////////////////////////////////////////////////////////////////////////
33//                Extern global variables
34//////////////////////////////////////////////////////////////////////////////
35
36extern char               * lock_type_str[];    // allocated in kernel_init.c
37extern chdev_directory_t    chdev_dir;          // allocated in kernel_init.c
38
39
40////////////////////////////////////////////
41void remote_busylock_init( xptr_t   lock_xp,
42                           uint32_t type )
43{
44    // get remote lock cluster and local pointer
45    cxy_t        lock_cxy = GET_CXY( lock_xp );
46    busylock_t * lock_ptr = GET_PTR( lock_xp );
47
48    hal_remote_s32( XPTR( lock_cxy , &lock_ptr->ticket  ) , 0 );
49    hal_remote_s32( XPTR( lock_cxy , &lock_ptr->current ) , 0 );
50    hal_remote_s32( XPTR( lock_cxy , &lock_ptr->type    ) , type );
51
52#if DEBUG_BUSYLOCK
53    xlist_entry_init( XPTR( lock_cxy , &lock_ptr->xlist ) ); 
54#endif
55
56}
57
58////////////////////////////////////////////////
59void remote_busylock_acquire( xptr_t   lock_xp )
60{
61    reg_t      save_sr;
62    thread_t * this = CURRENT_THREAD;
63
64    // get remote lock cluster and local pointer
65    cxy_t        lock_cxy = GET_CXY( lock_xp );
66    busylock_t * lock_ptr = GET_PTR( lock_xp );
67
68    // enter critical section
69    hal_disable_irq( &save_sr );
70 
71    // get one ticket
72    uint32_t ticket = hal_remote_atomic_add( XPTR( lock_cxy , &lock_ptr->ticket ) , 1 );
73
74    // poll current until success
75    xptr_t current_xp = XPTR( lock_cxy , &lock_ptr->current );
76    while( hal_remote_l32( current_xp ) != ticket ) asm volatile ("nop");
77
78    // increment thread locks counter
79    this->busylocks++;
80
81    // save SR in lock descriptor
82    hal_remote_s32( XPTR( lock_cxy , &lock_ptr->save_sr ) , save_sr );
83
84    // memory barrier to update busylock and thread state
85    hal_fence();
86   
87#if DEBUG_BUSYLOCK
88uint32_t type = hal_remote_l32( XPTR( lock_cxy , &lock_ptr->type ) );
89if( (type != LOCK_CHDEV_TXT0) &&
90    ((uint32_t)hal_get_cycles() > DEBUG_BUSYLOCK) )
91{
92    xptr_t root_xp = XPTR( local_cxy , &this->busylocks_root );
93
94    // update thread list of busyslocks
95    xlist_add_last( root_xp , XPTR( lock_cxy  , &lock_ptr->xlist ) );
96}
97#endif
98
99#if( DEBUG_BUSYLOCK && DEBUG_BUSYLOCK_THREAD_XP )
100if( (type != LOCK_CHDEV_TXT0) && 
101    (XPTR( local_cxy , this ) == DEBUG_BUSYLOCK_THREAD_XP) )
102{
103    printk("\n[%s] thread[%x,%x] ACQUIRE lock %s\n",
104    __FUNCTION__, this->process->pid, this->trdid, lock_type_str[type] );
105}
106#endif
107
108}  // end remote_busylock_acquire()
109
110///////////////////////////////////////////////
111void remote_busylock_release( xptr_t  lock_xp )
112{
113    thread_t * this = CURRENT_THREAD;
114
115    // memory barrier to update the protected object
116    hal_fence();
117
118    // get remote lock cluster and local pointer
119    cxy_t        lock_cxy = GET_CXY( lock_xp );
120    busylock_t * lock_ptr = GET_PTR( lock_xp );
121
122    // update lock state
123    hal_remote_atomic_add( XPTR( lock_cxy , &lock_ptr->current ) , 1 );
124
125    // decrement thread locks counter
126    this->busylocks--;
127
128    // memory barrier to update busylock and thread state
129    hal_fence();
130
131#if DEBUG_BUSYLOCK
132uint32_t type = hal_remote_l32( XPTR( lock_cxy , &lock_ptr->type ) );
133if( (type != LOCK_CHDEV_TXT0) && 
134    (XPTR( local_cxy , this ) == DEBUG_BUSYLOCK_THREAD_XP) &&
135    ((uint32_t)hal_get_cycles() > DEBUG_BUSYLOCK) )
136{
137    // remove lock from thread list of busyslocks
138    xlist_unlink( XPTR( lock_cxy  , &lock_ptr->xlist ) );
139}
140#endif
141
142#if (DEBUG_BUSYLOCK && DEBUG_BUSYLOCK_THREAD_XP )
143if( (type != LOCK_CHDEV_TXT0) && 
144    (XPTR( local_cxy , this ) == DEBUG_BUSYLOCK_THREAD_XP) )
145{
146    printk("\n[%s] thread[%x,%x] RELEASE lock %s\n",
147    __FUNCTION__, this->process->pid, this->trdid, lock_type_str[type] );
148}
149#endif
150                                 
151    // exit critical section
152    hal_restore_irq( hal_remote_l32( XPTR( lock_cxy , &lock_ptr->save_sr ) ) );
153 
154}  // end remote_busylock_release()
155
156
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