| 1 | /* |
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| 2 | * sys_read.c - Kernel function implementing the "read" system call. |
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| 3 | * |
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| 4 | * Author Alain Greiner (2016,2017,2018,2019) |
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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_vmm.h> |
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| 27 | #include <hal_uspace.h> |
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| 28 | #include <hal_irqmask.h> |
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| 29 | #include <hal_special.h> |
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| 30 | #include <errno.h> |
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| 31 | #include <vfs.h> |
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| 32 | #include <vmm.h> |
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| 33 | #include <thread.h> |
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| 34 | #include <printk.h> |
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| 35 | #include <process.h> |
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| 36 | |
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| 37 | |
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| 38 | extern uint32_t enter_sys_read; |
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| 39 | extern uint32_t enter_devfs_read; |
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| 40 | extern uint32_t enter_txt_read; |
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| 41 | extern uint32_t enter_chdev_cmd_read; |
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| 42 | extern uint32_t enter_chdev_server_read; |
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| 43 | extern uint32_t enter_tty_cmd_read; |
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| 44 | extern uint32_t enter_tty_isr_read; |
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| 45 | extern uint32_t exit_tty_isr_read; |
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| 46 | extern uint32_t exit_tty_cmd_read; |
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| 47 | extern uint32_t exit_chdev_server_read; |
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| 48 | extern uint32_t exit_chdev_cmd_read; |
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| 49 | extern uint32_t exit_txt_read; |
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| 50 | extern uint32_t exit_devfs_read; |
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| 51 | extern uint32_t exit_sys_read; |
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| 52 | |
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| 53 | |
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| 54 | ///////////////////////////////// |
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| 55 | int sys_read( uint32_t file_id, |
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| 56 | void * vaddr, |
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| 57 | uint32_t count ) |
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| 58 | { |
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| 59 | error_t error; |
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| 60 | vseg_t * vseg; // required for user space checking |
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| 61 | xptr_t file_xp; // remote file extended pointer |
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| 62 | vfs_file_t * file_ptr; // remote file local pointer |
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| 63 | cxy_t file_cxy; // remote file cluster identifier |
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| 64 | uint32_t file_type; // file type |
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| 65 | uint32_t file_attr; // file_attribute |
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| 66 | uint32_t nbytes; // number of bytes actually read |
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| 67 | reg_t save_sr; // required to enable IRQs during syscall |
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| 68 | |
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| 69 | thread_t * this = CURRENT_THREAD; |
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| 70 | process_t * process = this->process; |
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| 71 | xptr_t process_owner_xp = process->owner_xp; |
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| 72 | |
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| 73 | #if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS) |
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| 74 | uint64_t tm_start = hal_get_cycles(); |
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| 75 | #endif |
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| 76 | |
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| 77 | #if DEBUG_SYS_READ |
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| 78 | if( DEBUG_SYS_READ < tm_start ) |
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| 79 | printk("\n[%s] thread[%x,%x] enter / vaddr %x / count %d / cycle %d\n", |
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| 80 | __FUNCTION__, process->pid, this->trdid, vaddr, count, (uint32_t)tm_start ); |
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| 81 | #endif |
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| 82 | |
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| 83 | #if (DEBUG_SYS_READ & 1) |
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| 84 | enter_sys_read = (uint32_t)tm_start; |
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| 85 | #endif |
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| 86 | |
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| 87 | // check file_id argument |
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| 88 | if( file_id >= CONFIG_PROCESS_FILE_MAX_NR ) |
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| 89 | { |
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| 90 | |
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| 91 | #if DEBUG_SYSCALLS_ERROR |
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| 92 | printk("\n[ERROR] in %s : thread[%x,%x] illegal file descriptor index %d\n", |
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| 93 | __FUNCTION__ , process->pid, this->trdid, file_id ); |
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| 94 | #endif |
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| 95 | this->errno = EBADFD; |
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| 96 | return -1; |
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| 97 | } |
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| 98 | |
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| 99 | // check user buffer in user space |
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| 100 | error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg ); |
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| 101 | |
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| 102 | if ( error ) |
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| 103 | { |
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| 104 | |
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| 105 | #if DEBUG_SYSCALLS_ERROR |
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| 106 | printk("\n[ERROR] in %s : thread[%x,%x] user buffer unmapped %x\n", |
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| 107 | __FUNCTION__ , process->pid, this->trdid, (intptr_t)vaddr ); |
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| 108 | #endif |
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| 109 | this->errno = EINVAL; |
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| 110 | return -1; |
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| 111 | } |
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| 112 | |
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| 113 | // get extended pointer on remote file descriptor |
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| 114 | file_xp = process_fd_get_xptr( process , file_id ); |
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| 115 | |
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| 116 | if( file_xp == XPTR_NULL ) |
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| 117 | { |
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| 118 | |
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| 119 | #if DEBUG_SYSCALLS_ERROR |
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| 120 | printk("\n[ERROR] in %s : thread[%x,%x] undefined fd_id %d\n", |
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| 121 | __FUNCTION__, process->pid, this->trdid, file_id ); |
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| 122 | #endif |
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| 123 | this->errno = EBADFD; |
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| 124 | return -1; |
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| 125 | } |
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| 126 | |
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| 127 | // get file descriptor cluster and local pointer |
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| 128 | file_ptr = GET_PTR( file_xp ); |
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| 129 | file_cxy = GET_CXY( file_xp ); |
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| 130 | |
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| 131 | // get file type and attributes |
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| 132 | file_type = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) ); |
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| 133 | file_attr = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) ); |
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| 134 | |
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| 135 | // enable IRQs |
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| 136 | hal_enable_irq( &save_sr ); |
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| 137 | |
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| 138 | // action depend on file type |
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| 139 | if( file_type == INODE_TYPE_FILE ) // read from file mapper |
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| 140 | { |
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| 141 | // check file readable |
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| 142 | if( (file_attr & FD_ATTR_READ_ENABLE) == 0 ) |
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| 143 | { |
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| 144 | |
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| 145 | #if DEBUG_SYSCALLS_ERROR |
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| 146 | printk("\n[ERROR] in %s : thread[%x,%x] file %d not readable\n", |
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| 147 | __FUNCTION__, process->pid, this->trdid, file_id ); |
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| 148 | #endif |
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| 149 | hal_restore_irq( save_sr ); |
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| 150 | this->errno = EBADFD; |
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| 151 | return -1; |
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| 152 | } |
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| 153 | |
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| 154 | // move count bytes from mapper |
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| 155 | nbytes = vfs_user_move( true, // from mapper to buffer |
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| 156 | file_xp, |
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| 157 | vaddr, |
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| 158 | count ); |
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| 159 | if( nbytes != count ) |
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| 160 | { |
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| 161 | |
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| 162 | #if DEBUG_SYSCALLS_ERROR |
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| 163 | printk("\n[ERROR] in %s : thread[%x,‰x] cannot read %d bytes from file %d\n", |
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| 164 | __FUNCTION__, process->pid, this->trdid, count, file_id ); |
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| 165 | #endif |
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| 166 | this->errno = EIO; |
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| 167 | hal_restore_irq( save_sr ); |
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| 168 | return -1; |
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| 169 | } |
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| 170 | } |
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| 171 | else if( file_type == INODE_TYPE_DEV ) // read from TXT device |
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| 172 | { |
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| 173 | // get cluster and pointers on TXT_RX chdev |
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| 174 | xptr_t chdev_xp = chdev_from_file( file_xp ); |
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| 175 | cxy_t chdev_cxy = GET_CXY( chdev_xp ); |
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| 176 | chdev_t * chdev_ptr = GET_PTR( chdev_xp ); |
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| 177 | |
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| 178 | volatile xptr_t txt_owner_xp; |
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| 179 | uint32_t iter = 0; |
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| 180 | |
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| 181 | while( 1 ) |
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| 182 | { |
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| 183 | // extended pointer on TXT owner process |
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| 184 | txt_owner_xp = hal_remote_l64( XPTR( chdev_cxy , &chdev_ptr->ext.txt.owner_xp ) ); |
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| 185 | |
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| 186 | // check TXT_RX ownership |
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| 187 | if ( process_owner_xp != txt_owner_xp ) |
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| 188 | { |
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| 189 | if( (iter & 0xFFF) == 0 ) |
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| 190 | printk("\n[WARNING] in %s : thread[%x,%x] wait TXT_RX / cycle %d\n", |
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| 191 | __FUNCTION__, process->pid, this->trdid, (uint32_t)hal_get_cycles() ); |
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| 192 | |
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| 193 | // deschedule without blocking |
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| 194 | sched_yield( "wait TXT_RX ownership" ); |
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| 195 | |
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| 196 | iter++; |
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| 197 | } |
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| 198 | else |
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| 199 | { |
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| 200 | break; |
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| 201 | } |
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| 202 | } |
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| 203 | |
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| 204 | // move count bytes from device |
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| 205 | nbytes = devfs_user_move( true, // from device to buffer |
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| 206 | file_xp, |
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| 207 | vaddr, |
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| 208 | count ); |
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| 209 | if( nbytes != count ) |
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| 210 | { |
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| 211 | |
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| 212 | #if DEBUG_SYSCALLS_ERROR |
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| 213 | printk("\n[ERROR] in %s : thread[%x,‰x] cannot read data from file %d\n", |
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| 214 | __FUNCTION__, process->pid, this->trdid, file_id ); |
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| 215 | #endif |
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| 216 | this->errno = EIO; |
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| 217 | hal_restore_irq( save_sr ); |
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| 218 | return -1; |
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| 219 | } |
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| 220 | } |
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| 221 | else // not FILE and not DEV |
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| 222 | { |
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| 223 | |
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| 224 | #if DEBUG_SYSCALLS_ERROR |
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| 225 | printk("\n[ERROR] in %s : thread[%x,%x] / illegal inode type %\n", |
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| 226 | __FUNCTION__, vfs_inode_type_str( file_type ) ); |
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| 227 | #endif |
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| 228 | this->errno = EBADFD; |
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| 229 | hal_restore_irq( save_sr ); |
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| 230 | return -1; |
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| 231 | } |
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| 232 | |
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| 233 | // restore IRQs |
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| 234 | hal_restore_irq( save_sr ); |
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| 235 | |
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| 236 | hal_fence(); |
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| 237 | |
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| 238 | #if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS) |
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| 239 | uint64_t tm_end = hal_get_cycles(); |
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| 240 | #endif |
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| 241 | |
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| 242 | #if DEBUG_SYS_READ |
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| 243 | if( DEBUG_SYS_READ < tm_end ) |
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| 244 | printk("\n[%s] thread[%x,%x] exit / cycle %d\n", |
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| 245 | __FUNCTION__ , process->pid, this->trdid, (uint32_t)tm_end ); |
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| 246 | #endif |
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| 247 | |
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| 248 | #if CONFIG_INSTRUMENTATION_SYSCALLS |
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| 249 | hal_atomic_add( &syscalls_cumul_cost[SYS_READ] , tm_end - tm_start ); |
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| 250 | hal_atomic_add( &syscalls_occurences[SYS_READ] , 1 ); |
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| 251 | #endif |
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| 252 | |
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| 253 | #if (DEBUG_SYS_READ & 1) |
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| 254 | exit_sys_read = (uint32_t)tm_end; |
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| 255 | |
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| 256 | printk("\n***** timing to read one character *****\n" |
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| 257 | " - enter_sys_read = %d / delta %d\n" |
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| 258 | " - enter_devfs_read = %d / delta %d\n" |
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| 259 | " - enter_txt_read = %d / delta %d\n" |
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| 260 | " - enter_chdev_cmd_read = %d / delta %d\n" |
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| 261 | " - enter_chdev_server_read = %d / delta %d\n" |
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| 262 | " - enter_tty_cmd_read = %d / delta %d\n" |
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| 263 | " - enter_tty_isr_read = %d / delta %d\n" |
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| 264 | " - exit_tty_isr_read = %d / delta %d\n" |
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| 265 | " - exit_tty_cmd_read = %d / delta %d\n" |
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| 266 | " - exit_chdev_server_read = %d / delta %d\n" |
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| 267 | " - exit_chdev_cmd_read = %d / delta %d\n" |
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| 268 | " - exit_txt_read = %d / delta %d\n" |
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| 269 | " - exit_devfs_read = %d / delta %d\n" |
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| 270 | " - exit_sys_read = %d / delta %d\n", |
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| 271 | enter_sys_read , 0 , |
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| 272 | enter_devfs_read , enter_devfs_read - enter_sys_read , |
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| 273 | enter_txt_read , enter_txt_read - enter_devfs_read , |
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| 274 | enter_chdev_cmd_read , enter_chdev_cmd_read - enter_txt_read , |
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| 275 | enter_chdev_server_read , enter_chdev_server_read - enter_chdev_cmd_read , |
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| 276 | enter_tty_cmd_read , enter_tty_cmd_read - enter_chdev_server_read , |
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| 277 | enter_tty_isr_read , enter_tty_isr_read - enter_tty_cmd_read , |
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| 278 | exit_tty_isr_read , exit_tty_isr_read - enter_tty_isr_read , |
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| 279 | exit_tty_cmd_read , exit_tty_cmd_read - exit_tty_isr_read , |
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| 280 | exit_chdev_server_read , exit_chdev_server_read - exit_tty_cmd_read , |
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| 281 | exit_chdev_cmd_read , exit_chdev_cmd_read - exit_chdev_server_read , |
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| 282 | exit_txt_read , exit_txt_read - exit_chdev_cmd_read , |
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| 283 | exit_devfs_read , exit_devfs_read - exit_txt_read , |
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| 284 | exit_sys_read , exit_sys_read - exit_devfs_read ); |
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| 285 | #endif |
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| 286 | |
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| 287 | return nbytes; |
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| 288 | |
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| 289 | } // end sys_read() |
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