source: trunk/kernel/syscalls/sys_write.c @ 635

Last change on this file since 635 was 635, checked in by alain, 17 months ago

This version is a major evolution: The physical memory allocators,
defined in the kmem.c, ppm.c, and kcm.c files have been modified
to support remote accesses. The RPCs that were previously user
to allocate physical memory in a remote cluster have been removed.
This has been done to cure a dead-lock in case of concurrent page-faults.

This version 2.2 has been tested on a (4 clusters / 2 cores per cluster)
TSAR architecture, for both the "sort" and the "fft" applications.

File size: 8.9 KB
Line 
1/*
2 * sys_write.c - Kernel function implementing the "write" system call.
3 *
4 * Author        Alain Greiner (2016,2017,2018,2019)
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_vmm.h>
27#include <hal_uspace.h>
28#include <hal_irqmask.h>
29#include <hal_special.h>
30#include <errno.h>
31#include <vfs.h>
32#include <vmm.h>
33#include <thread.h>
34#include <printk.h>
35#include <process.h>
36
37
38extern uint32_t enter_sys_write;
39extern uint32_t enter_devfs_write;
40extern uint32_t enter_txt_write;
41extern uint32_t enter_chdev_cmd_write;
42extern uint32_t enter_chdev_server_write;
43extern uint32_t enter_tty_cmd_write;
44extern uint32_t enter_tty_isr_write;
45extern uint32_t exit_tty_isr_write;
46extern uint32_t exit_tty_cmd_write;
47extern uint32_t exit_chdev_server_write;
48extern uint32_t exit_chdev_cmd_write;
49extern uint32_t exit_txt_write;
50extern uint32_t exit_devfs_write;
51extern uint32_t exit_sys_write;
52
53//////////////////////////////////
54int sys_write( uint32_t   file_id,
55               void     * vaddr,
56               uint32_t   count )
57{
58    error_t       error;
59    vseg_t      * vseg;            // required for user space checking
60        xptr_t        file_xp;         // remote file extended pointer
61    vfs_file_t  * file_ptr;        // remote file local pointer
62    cxy_t         file_cxy;        // remote file cluster identifier
63    uint32_t      file_type;       // file type
64    uint32_t      file_offset;     // current file offset
65    uint32_t      file_attr;       // file_attribute
66    vfs_inode_t * inode_ptr;       // local pointer on associated inode
67    uint32_t      nbytes;          // number of bytes actually written
68    reg_t         save_sr;         // required to enable IRQs during syscall
69
70        thread_t    * this = CURRENT_THREAD;
71        process_t   * process = this->process;
72
73#if (DEBUG_SYS_WRITE || CONFIG_INSTRUMENTATION_SYSCALLS)
74uint64_t     tm_start = hal_get_cycles();
75#endif
76
77#if DEBUG_SYS_WRITE
78if( DEBUG_SYS_WRITE < tm_start )
79printk("\n[%s] thread[%x,%x] enter / vaddr %x / %d bytes / cycle %d\n",
80__FUNCTION__, process->pid, this->trdid, vaddr, count, (uint32_t)tm_start );
81#endif
82 
83#if (DEBUG_SYS_WRITE & 1)
84enter_sys_write = (uint32_t)tm_start;
85#endif
86
87    // check file_id argument
88        if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
89        {
90
91#if DEBUG_SYSCALLS_ERROR
92printk("\n[ERROR] in %s : thread[%x,%x] illegal file descriptor index %d\n",
93__FUNCTION__, process->pid, this->trdid, file_id );
94#endif
95        this->errno = EBADFD;
96                return -1;
97        }
98
99    // check user buffer in user space
100    error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg );
101
102    if ( error )
103    {
104
105#if DEBUG_SYSCALLS_ERROR
106printk("\n[ERROR] in %s : thread[%x,%x] user buffer unmapped %x\n",
107__FUNCTION__ , process->pid, this->trdid, (intptr_t)vaddr );
108#endif
109                this->errno = EINVAL;
110                return -1;
111    }
112
113    // get extended pointer on remote file descriptor
114    file_xp = process_fd_get_xptr( process , file_id );
115
116    if( file_xp == XPTR_NULL )
117    {
118
119#if DEBUG_SYSCALLS_ERROR
120printk("\n[ERROR] in %s : thread[%x,%x] undefined file descriptor = %d\n",
121__FUNCTION__, process->pid, this->trdid, file_id );
122#endif
123                this->errno = EBADFD;
124                return -1;
125    }
126
127    // get file descriptor cluster and local pointer
128    file_ptr = GET_PTR( file_xp );
129    file_cxy = GET_CXY( file_xp );
130
131    // get file type, offset, aatributes, and associated inode
132    file_type   = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) );
133    file_offset = hal_remote_l32( XPTR( file_cxy , &file_ptr->offset ) );
134    inode_ptr   = hal_remote_lpt( XPTR( file_cxy , &file_ptr->inode ) );
135    file_attr   = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) );
136
137    // enable IRQs
138    hal_enable_irq( &save_sr );
139
140    // action depend on file type
141    if( file_type == INODE_TYPE_FILE )  // write to a file mapper
142    {
143        // check file writable
144        if( (file_attr & FD_ATTR_WRITE_ENABLE) == 0 )
145            {
146
147#if DEBUG_SYSCALLS_ERROR
148printk("\n[ERROR] in %s : thread[%x,%x] file %d not writable\n",
149__FUNCTION__ , process->pid, this->trdid, file_id );
150#endif
151            hal_restore_irq( save_sr );
152                    this->errno = EBADFD;
153                    return -1;
154            }
155
156        // move count bytes to mapper
157        nbytes = vfs_user_move( false,               // from buffer to mapper
158                                file_xp,
159                                vaddr, 
160                                count );
161        if ( nbytes != count )
162        {
163
164#if DEBUG_SYSCALLS_ERROR
165printk("\n[ERROR] in %s : thread[%x,%x] cannot write %d bytes into file %d\n",
166__FUNCTION__ , process->pid, this->trdid, count, file_id );
167#endif
168            hal_restore_irq( save_sr );
169            this->errno = EIO;
170            return -1;
171
172        }
173
174        // update file size in inode descriptor
175        // only if (file_offset + count) > current_size
176        // note: the parent directory entry in mapper will
177        // be updated by the close syscall     
178        xptr_t inode_xp = XPTR( file_cxy , inode_ptr );
179        vfs_inode_update_size( inode_xp , file_offset + count );
180    }
181    else if( file_type == INODE_TYPE_DEV )  // write to TXT device
182    {
183        // move count bytes to device
184        nbytes = devfs_user_move( false,             // from buffer to device
185                                  file_xp,
186                                  vaddr,
187                                  count );
188        if( nbytes != count )
189        {
190
191#if DEBUG_SYSCALLS_ERROR
192printk("\n[ERROR] in %s : thread[%x,‰x] cannot write data to file %d\n",
193__FUNCTION__ , process->pid, this->trdid, file_id );
194#endif
195            hal_restore_irq( save_sr );
196            this->errno = EIO;
197            return -1;
198        }
199    }
200    else  // not FILE and not DEV
201    {
202
203#if DEBUG_SYSCALLS_ERROR
204printk("\n[ERROR] in %s : thread[%x,%x] / illegal inode type %\n",
205__FUNCTION__, vfs_inode_type_str( file_type ) );
206#endif
207        hal_restore_irq( save_sr );
208                this->errno = EBADFD;
209                return -1;
210    }
211
212    // restore IRQs
213    hal_restore_irq( save_sr );
214
215    hal_fence();
216
217#if (DEBUG_SYS_WRITE || CONFIG_INSTRUMENTATION_SYSCALLS)
218uint64_t     tm_end = hal_get_cycles();
219#endif
220
221#if DEBUG_SYS_WRITE
222if( DEBUG_SYS_WRITE < tm_end )
223printk("\n[%s] thread[%x,%x] exit / cycle %d\n",
224__FUNCTION__, process->pid, this->trdid, (uint32_t)tm_end );
225#endif
226 
227#if CONFIG_INSTRUMENTATION_SYSCALLS
228hal_atomic_add( &syscalls_cumul_cost[SYS_WRITE] , tm_end - tm_start );
229hal_atomic_add( &syscalls_occurences[SYS_WRITE] , 1 );
230#endif
231
232#if (DEBUG_SYS_WRITE & 1)
233exit_sys_write = (uint32_t)tm_end;
234
235printk("\n***** timing to write a string *****\n"
236" - enter_sys_write          = %d / delta %d\n"
237" - enter_devfs_write        = %d / delta %d\n"
238" - enter_txt_write          = %d / delta %d\n"
239" - enter_chdev_cmd_write    = %d / delta %d\n"
240" - enter_chdev_server_write = %d / delta %d\n"
241" - enter_tty_cmd_write      = %d / delta %d\n"
242" - enter_tty_isr_write      = %d / delta %d\n"
243" - exit_tty_isr_write       = %d / delta %d\n"
244" - exit_tty_cmd_write       = %d / delta %d\n"
245" - exit_chdev_server_write  = %d / delta %d\n"
246" - exit_chdev_cmd_write     = %d / delta %d\n"
247" - exit_txt_write           = %d / delta %d\n"
248" - exit_devfs_write         = %d / delta %d\n"
249" - exit_sys_write           = %d / delta %d\n",
250enter_sys_write          , 0 ,
251enter_devfs_write        , enter_devfs_write        - enter_sys_write          ,
252enter_txt_write          , enter_txt_write          - enter_devfs_write        ,
253enter_chdev_cmd_write    , enter_chdev_cmd_write    - enter_txt_write          ,
254enter_chdev_server_write , enter_chdev_server_write - enter_chdev_cmd_write    ,
255enter_tty_cmd_write      , enter_tty_cmd_write      - enter_chdev_server_write ,
256enter_tty_isr_write      , enter_tty_isr_write      - enter_tty_cmd_write      ,
257exit_tty_isr_write       , exit_tty_isr_write       - enter_tty_isr_write      ,
258exit_tty_cmd_write       , exit_tty_cmd_write       - exit_tty_isr_write       ,
259exit_chdev_server_write  , exit_chdev_server_write  - exit_tty_cmd_write       ,
260exit_chdev_cmd_write     , exit_chdev_cmd_write     - exit_chdev_server_write  ,
261exit_txt_write           , exit_txt_write           - exit_chdev_cmd_write     ,
262exit_devfs_write         , exit_devfs_write         - exit_txt_write           ,
263exit_sys_write           , exit_sys_write           - exit_devfs_write         );
264#endif
265 
266        return nbytes;
267
268}  // end sys_write()
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