| 1 | /*
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| 2 | * sys_read.c - read bytes from a file
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| 3 | *
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| 4 | * Author Alain Greiner (2016,2017,2018)
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| 5 | *
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| 6 | * Copyright (c) UPMC Sorbonne Universites
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| 7 | *
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| 8 | * This file is part of ALMOS-MKH.
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| 9 | *
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| 10 | * ALMOS-MKH is free software; you can redistribute it and/or modify it
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| 11 | * under the terms of the GNU General Public License as published by
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| 12 | * the Free Software Foundation; version 2.0 of the License.
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| 13 | *
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| 14 | * ALMOS-MKH is distributed in the hope that it will be useful, but
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| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of
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| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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| 17 | * General Public License for more details.
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| 18 | *
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| 19 | * You should have received a copy of the GNU General Public License
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| 20 | * along with ALMOS-MKH; if not, write to the Free Software Foundation,
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| 21 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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| 22 | */
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| 23 |
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| 24 | #include <kernel_config.h>
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| 25 | #include <hal_kernel_types.h>
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| 26 | #include <hal_uspace.h>
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| 27 | #include <hal_irqmask.h>
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| 28 | #include <hal_special.h>
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| 29 | #include <errno.h>
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| 30 | #include <vfs.h>
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| 31 | #include <vmm.h>
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| 32 | #include <thread.h>
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| 33 | #include <printk.h>
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| 34 | #include <process.h>
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| 35 |
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| 36 |
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| 37 | extern uint32_t enter_sys_read;
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| 38 | extern uint32_t enter_devfs_read;
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| 39 | extern uint32_t enter_txt_read;
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| 40 | extern uint32_t enter_chdev_cmd_read;
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| 41 | extern uint32_t enter_chdev_server_read;
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| 42 | extern uint32_t enter_tty_cmd_read;
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| 43 | extern uint32_t enter_tty_isr_read;
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| 44 | extern uint32_t exit_tty_isr_read;
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| 45 | extern uint32_t exit_tty_cmd_read;
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| 46 | extern uint32_t exit_chdev_server_read;
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| 47 | extern uint32_t exit_chdev_cmd_read;
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| 48 | extern uint32_t exit_txt_read;
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| 49 | extern uint32_t exit_devfs_read;
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| 50 | extern uint32_t exit_sys_read;
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| 51 |
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| 52 |
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| 53 | /////////////////////////////////
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| 54 | int sys_read( uint32_t file_id,
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| 55 | void * vaddr,
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| 56 | uint32_t count )
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| 57 | {
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| 58 | error_t error;
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| 59 | vseg_t * vseg; // required for user space checking
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| 60 | xptr_t file_xp; // remote file extended pointer
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| 61 | uint32_t nbytes; // number of bytes actually read
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| 62 | reg_t save_sr; // required to enable IRQs during syscall
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| 63 |
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| 64 | thread_t * this = CURRENT_THREAD;
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| 65 | process_t * process = this->process;
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| 66 | xptr_t process_owner_xp = process->owner_xp;
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| 67 |
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| 68 | #if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS)
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| 69 | uint64_t tm_start = hal_get_cycles();
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| 70 | #endif
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| 71 |
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| 72 | #if DEBUG_SYS_READ
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| 73 | if( DEBUG_SYS_READ < tm_start )
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| 74 | printk("\n[DBG] %s : thread[%x,%x] enter / vaddr %x / count %d / cycle %d\n",
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| 75 | __FUNCTION__, process->pid, this->trdid, vaddr, count, (uint32_t)tm_start );
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| 76 | #endif
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| 77 |
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| 78 | #if (DEBUG_SYS_READ & 1)
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| 79 | enter_sys_read = (uint32_t)tm_start;
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| 80 | #endif
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| 81 |
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| 82 | // check file_id argument
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| 83 | if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
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| 84 | {
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| 85 |
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| 86 | #if DEBUG_SYSCALLS_ERROR
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| 87 | printk("\n[ERROR] in %s : thread[%x,%x] illegal file descriptor index = %d\n",
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| 88 | __FUNCTION__ , process->pid, this->trdid, file_id );
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| 89 | #endif
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| 90 | this->errno = EBADFD;
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| 91 | return -1;
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| 92 | }
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| 93 |
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| 94 | // check user buffer in user space
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| 95 | error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg );
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| 96 |
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| 97 | if ( error )
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| 98 | {
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| 99 |
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| 100 | #if DEBUG_SYSCALLS_ERROR
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| 101 | printk("\n[ERROR] in %s : thread[%x,%x] user buffer unmapped %x\n",
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| 102 | __FUNCTION__ , process->pid, this->trdid, (intptr_t)vaddr );
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| 103 | vmm_display( process , false );
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| 104 | #endif
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| 105 | this->errno = EINVAL;
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| 106 | return -1;
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| 107 | }
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| 108 |
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| 109 | // enable IRQs
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| 110 | hal_enable_irq( &save_sr );
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| 111 |
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| 112 | // get extended pointer on remote file descriptor
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| 113 | file_xp = process_fd_get_xptr( process , file_id );
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| 114 |
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| 115 | if( file_xp == XPTR_NULL )
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| 116 | {
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| 117 |
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| 118 | #if DEBUG_SYSCALLS_ERROR
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| 119 | printk("\n[ERROR] in %s : thread[%x,%x] undefined fd_id %d\n",
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| 120 | __FUNCTION__, process->pid, this->trdid, file_id );
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| 121 | #endif
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| 122 | this->errno = EBADFD;
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| 123 | return -1;
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| 124 | }
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| 125 |
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| 126 | // get file descriptor cluster and local pointer
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| 127 | vfs_file_t * file_ptr = GET_PTR( file_xp );
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| 128 | cxy_t file_cxy = GET_CXY( file_xp );
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| 129 |
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| 130 | // get file type
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| 131 | vfs_inode_type_t type = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) );
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| 132 |
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| 133 | // action depend on file type
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| 134 | if( type == INODE_TYPE_FILE ) // check file readable & read from mapper
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| 135 | {
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| 136 | // check file readable
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| 137 | uint32_t attr = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) );
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| 138 |
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| 139 | if( (attr & FD_ATTR_READ_ENABLE) == 0 )
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| 140 | {
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| 141 |
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| 142 | #if DEBUG_SYSCALLS_ERROR
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| 143 | printk("\n[ERROR] in %s : thread[%x,%x] file %d not readable\n",
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| 144 | __FUNCTION__, process->pid, this->trdid, file_id );
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| 145 | #endif
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| 146 | this->errno = EBADFD;
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| 147 | return -1;
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| 148 | }
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| 149 |
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| 150 | // move count bytes from mapper
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| 151 | nbytes = vfs_user_move( true, // from mapper to buffer
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| 152 | file_xp,
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| 153 | vaddr,
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| 154 | count );
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| 155 | }
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| 156 | else if( type == INODE_TYPE_DEV ) // check ownership & read from device
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| 157 | {
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| 158 | // get cluster and pointers on TXT_RX chdev
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| 159 | xptr_t chdev_xp = chdev_from_file( file_xp );
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| 160 | cxy_t chdev_cxy = GET_CXY( chdev_xp );
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| 161 | chdev_t * chdev_ptr = GET_PTR( chdev_xp );
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| 162 |
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| 163 | volatile xptr_t txt_owner_xp;
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| 164 | uint32_t iter = 0;
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| 165 |
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| 166 | while( 1 )
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| 167 | {
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| 168 | // extended pointer on TXT owner process
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| 169 | txt_owner_xp = hal_remote_l64( XPTR( chdev_cxy , &chdev_ptr->ext.txt.owner_xp ) );
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| 170 |
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| 171 | // check TXT_RX ownership
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| 172 | if ( process_owner_xp != txt_owner_xp )
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| 173 | {
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| 174 | if( (iter & 0xFFF) == 0 )
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| 175 | printk("\n[WARNING] in %s : thread[%x,%x] wait TXT_RX / cycle %d\n",
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| 176 | __FUNCTION__, process->pid, this->trdid, (uint32_t)hal_get_cycles() );
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| 177 |
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| 178 | // deschedule without blocking
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| 179 | sched_yield( "wait TXT_RX ownership" );
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| 180 |
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| 181 | iter++;
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| 182 | }
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| 183 | else
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| 184 | {
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| 185 | break;
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| 186 | }
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| 187 | }
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| 188 |
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| 189 | // move count bytes from device
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| 190 | nbytes = devfs_user_move( true, // from device to buffer
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| 191 | file_xp,
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| 192 | vaddr,
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| 193 | count );
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| 194 |
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| 195 | }
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| 196 | else
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| 197 | {
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| 198 | nbytes = 0;
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| 199 | assert( false , "file type %d non supported yet\n", type );
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| 200 | }
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| 201 |
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| 202 | if( nbytes != count )
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| 203 | {
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| 204 |
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| 205 | #if DEBUG_SYSCALLS_ERROR
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| 206 | printk("\n[ERROR] in %s : thread[%x,‰x] cannot read data from file %d\n",
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| 207 | __FUNCTION__, process->pid, this->trdid, file_id );
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| 208 | #endif
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| 209 | this->errno = error;
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| 210 | return -1;
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| 211 | }
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| 212 |
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| 213 | // restore IRQs
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| 214 | hal_restore_irq( save_sr );
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| 215 |
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| 216 | hal_fence();
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| 217 |
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| 218 | #if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS)
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| 219 | uint64_t tm_end = hal_get_cycles();
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| 220 | #endif
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| 221 |
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| 222 | #if DEBUG_SYS_READ
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| 223 | if( DEBUG_SYS_READ < tm_end )
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| 224 | printk("\n[DBG] %s : thread[%x,%x] exit / cycle %d\n",
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| 225 | __FUNCTION__ , process->pid, this->trdid, (uint32_t)tm_end );
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| 226 | #endif
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| 227 |
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| 228 | #if CONFIG_INSTRUMENTATION_SYSCALLS
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| 229 | hal_atomic_add( &syscalls_cumul_cost[SYS_READ] , tm_end - tm_start );
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| 230 | hal_atomic_add( &syscalls_occurences[SYS_READ] , 1 );
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| 231 | #endif
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| 232 |
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| 233 | #if (DEBUG_SYS_READ & 1)
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| 234 | exit_sys_read = (uint32_t)tm_end;
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| 235 |
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| 236 | printk("\n***** timing to read one character *****\n"
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| 237 | " - enter_sys_read = %d / delta %d\n"
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| 238 | " - enter_devfs_read = %d / delta %d\n"
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| 239 | " - enter_txt_read = %d / delta %d\n"
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| 240 | " - enter_chdev_cmd_read = %d / delta %d\n"
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| 241 | " - enter_chdev_server_read = %d / delta %d\n"
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| 242 | " - enter_tty_cmd_read = %d / delta %d\n"
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| 243 | " - enter_tty_isr_read = %d / delta %d\n"
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| 244 | " - exit_tty_isr_read = %d / delta %d\n"
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| 245 | " - exit_tty_cmd_read = %d / delta %d\n"
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| 246 | " - exit_chdev_server_read = %d / delta %d\n"
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| 247 | " - exit_chdev_cmd_read = %d / delta %d\n"
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| 248 | " - exit_txt_read = %d / delta %d\n"
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| 249 | " - exit_devfs_read = %d / delta %d\n"
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| 250 | " - exit_sys_read = %d / delta %d\n",
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| 251 | enter_sys_read , 0 ,
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| 252 | enter_devfs_read , enter_devfs_read - enter_sys_read ,
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| 253 | enter_txt_read , enter_txt_read - enter_devfs_read ,
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| 254 | enter_chdev_cmd_read , enter_chdev_cmd_read - enter_txt_read ,
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| 255 | enter_chdev_server_read , enter_chdev_server_read - enter_chdev_cmd_read ,
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| 256 | enter_tty_cmd_read , enter_tty_cmd_read - enter_chdev_server_read ,
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| 257 | enter_tty_isr_read , enter_tty_isr_read - enter_tty_cmd_read ,
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| 258 | exit_tty_isr_read , exit_tty_isr_read - enter_tty_isr_read ,
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| 259 | exit_tty_cmd_read , exit_tty_cmd_read - exit_tty_isr_read ,
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| 260 | exit_chdev_server_read , exit_chdev_server_read - exit_tty_cmd_read ,
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| 261 | exit_chdev_cmd_read , exit_chdev_cmd_read - exit_chdev_server_read ,
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| 262 | exit_txt_read , exit_txt_read - exit_chdev_cmd_read ,
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| 263 | exit_devfs_read , exit_devfs_read - exit_txt_read ,
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| 264 | exit_sys_read , exit_sys_read - exit_devfs_read );
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| 265 | #endif
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| 266 |
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| 267 | return nbytes;
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| 268 |
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| 269 | } // end sys_read()
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