source: trunk/kernel/devices/dev_txt.c @ 527

Last change on this file since 527 was 527, checked in by viala@…, 3 years ago

Rewrite if-then-else return function into switch case.

For safety reason and performance:

1) Safety: GCC complain with a warning if you forgot an enum variant.
2) code-gen just outperform naive if-then-else.

File size: 7.5 KB
Line 
1/*
2 * dev_txt.c - TXT (Text Terminal) generic device API implementation.
3 *
4 * Author  Alain Greiner    (2016)
5 *
6 * Copyright (c) UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MK
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-kernel; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#include <hal_kernel_types.h>
25#include <hal_special.h>
26#include <hal_remote.h>
27#include <hal_drivers.h>
28#include <thread.h>
29#include <chdev.h>
30#include <rpc.h>
31#include <printk.h>
32#include <dev_txt.h>
33
34/////////////////////////////////////////////////////////////////////////////////////////
35// Extern global variables
36/////////////////////////////////////////////////////////////////////////////////////////
37
38extern chdev_directory_t  chdev_dir;         // allocated in kernel_init.c
39
40#if (DEBUG_SYS_READ & 1)
41extern uint32_t enter_txt_read;
42extern uint32_t exit_txt_read;
43#endif
44
45#if (DEBUG_SYS_WRITE & 1)
46extern uint32_t enter_txt_write;
47extern uint32_t exit_txt_write;
48#endif
49
50////////////////////////////////////////
51const char * dev_txt_type_str( dev_txt_cmd_t type )
52{
53  switch (type) {
54    case (TXT_SYNC_WRITE): return "TXT_SYNC_WRITE";
55    case (TXT_READ):       return "TXT_READ";
56    case (TXT_WRITE):      return "TXT_WRITE";
57    default:               return "undefined";
58  }
59}
60
61//////////////////////////////////
62void dev_txt_init( chdev_t * txt )
63{
64    // For all TXT channels other than the TXT0 (kernel terminal),
65    // the PIC chdev must be initialized before the TXT chdev, because
66    // the TXT chdev initialization requires the routing of an external IRQ
67
68    xptr_t    pic_xp  = chdev_dir.pic;
69    uint32_t  channel = txt->channel;
70    uint32_t  impl    = txt->impl;
71    bool_t    is_rx   = txt->is_rx;
72
73    assert( (pic_xp != XPTR_NULL) || (channel == 0) ,
74            "PIC not initialised before TXT" );
75
76    // set chdev name
77    if( is_rx ) snprintf( txt->name , 16 , "txt%d_rx" , channel );
78    else        snprintf( txt->name , 16 , "txt%d_tx" , channel );
79
80    // set TXT chdev extension
81    txt->ext.txt.owner_xp = XPTR_NULL;
82    xlist_root_init( XPTR( local_cxy, &txt->ext.txt.root ) );
83    remote_spinlock_init( XPTR( local_cxy , &txt->ext.txt.lock ) );
84   
85    // call driver init function
86    hal_drivers_txt_init(txt, impl);
87
88    // no server thread and no IRQ routing for TXT0
89    // no server thread for IMPL_TXT_RS2 (multiplexed in software, not hardware)
90    if( channel != 0 && impl != IMPL_TXT_RS2 )
91    {
92        // select a core to execute the server thread
93        lid_t lid = cluster_select_local_core();
94
95        // bind IRQ to the selected core
96        dev_pic_bind_irq( lid , txt );
97
98        // enable IRQ
99        dev_pic_enable_irq( lid , XPTR( local_cxy , txt ) );
100
101        // create server thread
102        thread_t * new_thread;
103        error_t    error;
104
105        error = thread_kernel_create( &new_thread,
106                                      THREAD_DEV,
107                                      &chdev_sequencial_server,
108                                      txt,
109                                      lid );
110
111        assert( (error == 0) , "cannot create server thread" );
112
113        // set "server" field in chdev descriptor
114        txt->server = new_thread;
115
116        // set "chdev" field in thread descriptor
117        new_thread->chdev = txt;
118
119        // unblock server thread
120        thread_unblock( XPTR( local_cxy , new_thread ) , THREAD_BLOCKED_GLOBAL );
121    }
122}
123
124//////////////////////////////////////////////////////////////////////////////////
125// This static function is called by dev_txt_read(), dev_txt_write() functions.
126////////////////////////////////////i/////////////////////////////////////////////
127static error_t dev_txt_access( uint32_t   type,
128                               uint32_t   channel,
129                               char     * buffer,
130                               uint32_t   count )
131{
132    xptr_t     dev_xp;
133    thread_t * this = CURRENT_THREAD;
134
135    // check channel argument
136    assert( (channel < CONFIG_MAX_TXT_CHANNELS) , "illegal channel index" );
137
138    // get extended pointer on remote TXT chdev descriptor
139    if( type == TXT_WRITE )  dev_xp = chdev_dir.txt_tx[channel];
140    else                     dev_xp = chdev_dir.txt_rx[channel];
141
142    assert( (dev_xp != XPTR_NULL) , "undefined TXT chdev descriptor" );
143
144    // register command in calling thread descriptor
145    this->txt_cmd.dev_xp  = dev_xp;
146    this->txt_cmd.type    = type;
147    this->txt_cmd.buf_xp  = XPTR( local_cxy , buffer );
148    this->txt_cmd.count   = count;
149
150    // register client thread in waiting queue, activate server thread
151    // block client thread on THREAD_BLOCKED_IO and deschedule.
152    // it is re-activated by the ISR signaling IO operation completion.
153    chdev_register_command( dev_xp );
154
155    // return I/O operation status from calling thread descriptor
156    return this->txt_cmd.error;
157}
158
159/////////////////////////////////////////
160error_t dev_txt_write( uint32_t   channel,
161                       char     * buffer,
162                       uint32_t   count )
163{
164
165#if (DEBUG_SYS_WRITE & 1)
166enter_txt_write = hal_time_stamp();
167#endif
168
169#if DEBUG_DEV_TXT_TX
170uint32_t cycle = (uint32_t)hal_get_cycles();
171if( DEBUG_DEV_TXT_TX < cycle )
172printk("\n[DBG] %s : thread %x enters / cycle %d\n", __FUNCTION__, CURRENT_THREAD, cycle );
173#endif
174
175    return dev_txt_access( TXT_WRITE , channel , buffer , count );
176
177#if DEBUG_DEV_TXT_TX
178cycle = (uint32_t)hal_get_cycles();
179if( DEBUG_DEV_TXT_TX < cycle )
180printk("\n[DBG] %s : thread %x exit / cycle %d\n", __FUNCTION__, CURRENT_THREAD, cycle );
181#endif
182
183#if (DEBUG_SYS_WRITE & 1)
184exit_txt_write = hal_time_stamp();
185#endif
186
187}
188
189/////////////////////////////////////////
190error_t dev_txt_read( uint32_t   channel,
191                      char     * buffer )
192{
193
194#if (DEBUG_SYS_READ & 1)
195enter_txt_read = hal_time_stamp();
196#endif
197
198#if DEBUG_DEV_TXT_RX
199uint32_t cycle = (uint32_t)hal_get_cycles();
200if( DEBUG_DEV_TXT_RX < cycle )
201printk("\n[DBG] %s : thread %x enters / cycle %d\n", __FUNCTION__, CURRENT_THREAD, cycle );
202#endif
203
204    return dev_txt_access( TXT_READ , channel , buffer , 1 );
205
206#if DEBUG_DEV_TXT_RX
207cycle = (uint32_t)hal_get_cycles();
208if( DEBUG_DEV_TXT_RX < cycle )
209printk("\n[DBG] %s : thread %x exit / cycle %d\n", __FUNCTION__, CURRENT_THREAD, cycle );
210#endif
211
212#if (DEBUG_SYS_READ & 1)
213exit_txt_read = hal_time_stamp();
214#endif
215
216}
217
218//////////////////////////////////////////////
219error_t dev_txt_sync_write( char     * buffer,
220                            uint32_t   count )
221{
222    // get extended pointer on TXT[0] chdev
223    xptr_t  dev_xp = chdev_dir.txt_tx[0];
224
225    assert( (dev_xp != XPTR_NULL) ,
226    "undefined TXT0 chdev descriptor" );
227
228    // get TXTO chdev cluster and local pointer
229    cxy_t    dev_cxy  = GET_CXY( dev_xp );
230    chdev_t * dev_ptr = (chdev_t *)GET_PTR( dev_xp );
231
232    // get driver command function
233    dev_aux_t * aux = (dev_aux_t *)hal_remote_lpt( XPTR( dev_cxy , &dev_ptr->aux ) );
234
235    // build arguments structure
236    txt_sync_args_t  args;
237    args.dev_xp = dev_xp;
238    args.buffer = buffer;
239    args.count  = count;
240
241    // call driver function
242    aux( &args );
243
244    return 0;
245}
246
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