[1] | 1 | /* |
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| 2 | * hal_uspace.c - implementation of Generic User Space Access API for MIPS32 |
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| 3 | * |
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[657] | 4 | * Author Alain Greiner (2016,2017,2018,2019,2020) |
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[1] | 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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[457] | 24 | #include <hal_kernel_types.h> |
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[1] | 25 | #include <hal_uspace.h> |
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[626] | 26 | #include <hal_special.h> |
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[1] | 27 | #include <hal_irqmask.h> |
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| 28 | |
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[425] | 29 | #include <printk.h> |
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| 30 | #include <thread.h> |
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| 31 | |
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[626] | 32 | /////////////////////////////////////////////////////////////////////////////////////// |
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[658] | 33 | // Implementation note |
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[637] | 34 | // It works in a critical section, as it modifies two CP2 registers: |
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[626] | 35 | // It activates briefly the DATA_MMU by writing into the CP2_MODE register to access the |
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[654] | 36 | // user buffer, and modifies the CP2_DEXT register to access the kernel buffer. |
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[626] | 37 | // If the two buffers are aligned on a word boundary, it moves the data word per word |
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| 38 | // in a first loop, and moves byte per byte the remaining bytes in a second loop. |
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| 39 | // If the buffers are not aligned, it moves all data byte per byte. |
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| 40 | /////////////////////////////////////////////////////////////////////////////////////// |
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[637] | 41 | void hal_copy_from_uspace( xptr_t k_dst_xp, |
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| 42 | void * u_src_ptr, |
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[425] | 43 | uint32_t size ) |
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[1] | 44 | { |
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| 45 | uint32_t save_sr; |
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[637] | 46 | uint32_t words; // number of words (if buffers aligned) |
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| 47 | uint32_t src = (uint32_t)u_src_ptr; |
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| 48 | uint32_t dst = (uint32_t)GET_PTR( k_dst_xp ); |
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| 49 | uint32_t cxy = (uint32_t)GET_CXY( k_dst_xp ); |
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[626] | 50 | |
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[658] | 51 | assert( (CURRENT_THREAD->process->pid > 0), "must be called by an user thread" ); |
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| 52 | |
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[610] | 53 | #if DEBUG_HAL_USPACE |
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[626] | 54 | thread_t * this = CURRENT_THREAD; |
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| 55 | uint32_t cycle = (uint32_t)hal_get_cycles(); |
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| 56 | if( cycle > DEBUG_HAL_USPACE ) |
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| 57 | printk("\n[%s] thread[%x,%x] enter / %d bytes / u_buf(%x,%x) -> k_buf(%x,%x) / cycle %d\n", |
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[637] | 58 | __FUNCTION__, this->process->pid, this->trdid, size, local_cxy, src, cxy, dst, cycle ); |
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[610] | 59 | #endif |
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| 60 | |
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[626] | 61 | if( (dst & 0x3) || (src & 0x3) ) words = 0; // do it all in bytes |
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| 62 | else words = size >> 2; |
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[1] | 63 | |
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[626] | 64 | // enter critical section |
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[1] | 65 | hal_disable_irq( &save_sr ); |
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| 66 | |
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[626] | 67 | asm volatile( ".set noreorder \n" |
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| 68 | |
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| 69 | /* initialise registers */ |
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| 70 | "move $8, %0 \n" /* $8 <= src */ |
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| 71 | "move $9, %1 \n" /* $9 <= dst */ |
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| 72 | "move $10, %2 \n" /* $10 <= words */ |
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| 73 | "move $11, %3 \n" /* $11 <= size */ |
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| 74 | "mfc2 $12, $1 \n" /* $12 <= old MMU_MODE */ |
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| 75 | "ori $13, $12, 0x4 \n" /* $13 <= MMU_MODE with DTLB */ |
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[407] | 76 | |
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[654] | 77 | /* save MMU_DEXT register */ |
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| 78 | "mfc2 $16, $24 \n" /* $16 <= old MMU_DEXT */ |
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| 79 | "mtc2 %4, $24 \n" /* MMU_DEXT <= dst_cxy */ |
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[1] | 80 | |
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[626] | 81 | /* transfer one word per iteration in first loop if aligned */ |
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| 82 | "move $15, $10 \n" /* $15 <= words ($15 == i) */ |
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| 83 | "1: \n" |
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| 84 | "beq $15, $0, 2f \n" /* exit loop if (i==0) */ |
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| 85 | "nop \n" |
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| 86 | "mtc2 $13, $1 \n" /* MMU_MODE <= DTLB ON */ |
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| 87 | "lw $14, 0($8) \n" /* word from user space */ |
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| 88 | "mtc2 $12, $1 \n" /* restore old MMU_MODE */ |
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| 89 | "sw $14, 0($9) \n" /* word to kernel space */ |
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| 90 | "addi $15, $15, -1 \n" /* i-- */ |
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| 91 | "addi $8, $8, 4 \n" /* src += 4 bytes */ |
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| 92 | "j 1b \n" |
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| 93 | "addi $9, $9, 4 \n" /* dst += 4 bytes */ |
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[1] | 94 | |
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[626] | 95 | /* transfer one byte per iteration in this second loop */ |
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| 96 | "2: \n" |
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| 97 | "sll $15, $10, 2 \n" /* $15 <= words*4 ($15 == i) */ |
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| 98 | "3: \n" |
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| 99 | "beq $15, $11, 4f \n" /* exit loop if (i == size) */ |
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| 100 | "nop \n" |
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| 101 | "mtc2 $13, $1 \n" /* MMU_MODE <= DTLB ON */ |
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| 102 | "lb $14, 0($8) \n" /* byte from user space */ |
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| 103 | "mtc2 $12, $1 \n" /* restore omd MMU_MODE */ |
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| 104 | "sb $14, 0($9) \n" /* byte to kernel space */ |
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| 105 | "addi $15, $15, 1 \n" /* i++ */ |
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| 106 | "addi $8, $8, 1 \n" /* src += 1 byte */ |
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| 107 | "j 3b \n" |
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| 108 | "addi $9, $9, 1 \n" /* dst += 1 byte */ |
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[1] | 109 | |
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[654] | 110 | /* restore MMU_DEXT register */ |
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[626] | 111 | "4: \n" |
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[654] | 112 | "mtc2 $16, $24 \n" /* MMU_DEXT <= $16 */ |
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[626] | 113 | ".set reorder \n" |
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| 114 | : |
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[637] | 115 | : "r"(src) , "r"(dst) , "r"(words) , "r"(size) , "r"(cxy) |
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[626] | 116 | : "$8","$9","$10","$11","$12","$13","$14","$15","$16","memory" ); |
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[1] | 117 | |
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[626] | 118 | // exit critical section |
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[1] | 119 | hal_restore_irq( save_sr ); |
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| 120 | |
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[610] | 121 | #if DEBUG_HAL_USPACE |
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[626] | 122 | cycle = (uint32_t)hal_get_cycles(); |
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| 123 | if( cycle > DEBUG_HAL_USPACE ) |
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| 124 | printk("\n[%s] thread[%x,%x] moved %d bytes / u_buf(%x,%x) -> k_buf(%x,%x) / cycle %d\n", |
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[637] | 125 | __FUNCTION__, this->process->pid, this->trdid, size, local_cxy, src, cxy, dst, cycle ); |
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[610] | 126 | #endif |
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| 127 | |
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[87] | 128 | } // end hal_copy_from_uspace() |
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| 129 | |
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[626] | 130 | /////////////////////////////////////////////////////////////////////////////////////// |
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[658] | 131 | // Implementation note |
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[637] | 132 | // It works in a critical section, as it modifies two CP2 registers: |
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[626] | 133 | // It activates briefly the DATA_MMU by writing into the CP2_MODE register to access the |
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[654] | 134 | // user buffer, and modifies the CP2_DEXT register to access the kernel buffer. |
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[626] | 135 | // If the two buffers are aligned on a word boundary, it moves the data word per word |
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| 136 | // in a first loop, and moves byte per byte the remaining bytes in a second loop. |
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[647] | 137 | // If the buffers are not word aligned, it moves all data byte per byte. |
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[626] | 138 | /////////////////////////////////////////////////////////////////////////////////////// |
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[637] | 139 | void hal_copy_to_uspace( void * u_dst_ptr, |
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| 140 | xptr_t k_src_xp, |
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[1] | 141 | uint32_t size ) |
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| 142 | { |
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| 143 | uint32_t save_sr; |
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[637] | 144 | uint32_t words; // number of words (if buffers aligned) |
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| 145 | uint32_t dst = (uint32_t)u_dst_ptr; |
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| 146 | uint32_t src = (uint32_t)GET_PTR( k_src_xp ); |
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| 147 | uint32_t cxy = (uint32_t)GET_CXY( k_src_xp ); |
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[1] | 148 | |
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[658] | 149 | assert( (CURRENT_THREAD->process->pid > 0), "must be called by an user thread" ); |
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| 150 | |
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[610] | 151 | #if DEBUG_HAL_USPACE |
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[626] | 152 | thread_t * this = CURRENT_THREAD; |
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| 153 | uint32_t cycle = (uint32_t)hal_get_cycles(); |
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| 154 | if( cycle > DEBUG_HAL_USPACE ) |
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| 155 | printk("\n[%s] thread[%x,%x] enter / %d bytes / k_buf(%x,%x) -> u_buf(%x,%x) / cycle %d\n", |
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[637] | 156 | __FUNCTION__, this->process->pid, this->trdid, size, cxy, src, local_cxy, dst, cycle ); |
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[610] | 157 | #endif |
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| 158 | |
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[626] | 159 | if( (dst & 0x3) || (src & 0x3) ) words = 0; // not aligned |
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| 160 | else words = size >> 2; |
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[1] | 161 | |
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[626] | 162 | // enter critical section |
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[1] | 163 | hal_disable_irq( &save_sr ); |
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| 164 | |
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[626] | 165 | asm volatile( ".set noreorder \n" |
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| 166 | |
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| 167 | /* initialise registers */ |
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| 168 | "move $8, %0 \n" /* $8 <= k_src */ |
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| 169 | "move $9, %1 \n" /* $9 <= u_dst */ |
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| 170 | "move $10, %2 \n" /* $10 <= words */ |
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| 171 | "move $11, %3 \n" /* $11 <= size */ |
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| 172 | "mfc2 $12, $1 \n" /* $12 <= old MMU_MODE */ |
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| 173 | "ori $13, $12, 0x4 \n" /* $13 <= MMU_MODE with DTLB */ |
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[1] | 174 | |
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[654] | 175 | /* save MMU_DEXT register */ |
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| 176 | "mfc2 $16, $24 \n" /* $16 <= old MMU_DEXT */ |
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| 177 | "mtc2 %4, $24 \n" /* MMU_DEXT <= cxy */ |
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[1] | 178 | |
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[626] | 179 | /* transfer one word per iteration in first loop if aligned */ |
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| 180 | "move $15, $10 \n" /* $15 <= words ($15 == i) */ |
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| 181 | "1: \n" |
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| 182 | "beq $15, $0, 2f \n" /* exit loop if (i==0) */ |
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| 183 | "nop \n" |
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| 184 | "lw $14, 0($8) \n" /* load from kernel space */ |
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| 185 | "mtc2 $13, $1 \n" /* MMU_MODE <= DTLB ON */ |
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| 186 | "sw $14, 0($9) \n" /* store to user space */ |
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| 187 | "mtc2 $12, $1 \n" /* restore old MMU_MODE */ |
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| 188 | "addi $15, $15, -1 \n" /* i-- */ |
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| 189 | "addi $8, $8, 4 \n" /* src += 4 bytes */ |
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| 190 | "j 1b \n" |
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| 191 | "addi $9, $9, 4 \n" /* dst += 4 bytes */ |
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[1] | 192 | |
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[626] | 193 | /* transfer one byte per iteration in this second loop */ |
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| 194 | "2: \n" |
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| 195 | "sll $15, $10, 2 \n" /* $15 <= words*4 ($15 == i) */ |
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| 196 | "3: \n" |
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| 197 | "beq $15, $11, 4f \n" /* exit loop if (i == size) */ |
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| 198 | "nop \n" |
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| 199 | "lb $14, 0($8) \n" /* byte from kernel space */ |
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| 200 | "mtc2 $13, $1 \n" /* MMU_MODE <= DTLB ON */ |
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| 201 | "sb $14, 0($9) \n" /* byte to user space */ |
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| 202 | "mtc2 $12, $1 \n" /* restore omd MMU_MODE */ |
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| 203 | "addi $15, $15, 1 \n" /* i++ */ |
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| 204 | "addi $8, $8, 1 \n" /* src += 1 byte */ |
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| 205 | "j 3b \n" |
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| 206 | "addi $9, $9, 1 \n" /* dst += 1 byte */ |
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[1] | 207 | |
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[654] | 208 | /* restore MMU_DEXT register */ |
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[626] | 209 | "4: \n" |
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[654] | 210 | "mtc2 $16, $24 \n" /* MMU_DEXT <= $16 */ |
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[626] | 211 | ".set reorder \n" |
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| 212 | : |
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[637] | 213 | : "r"(src) , "r"(dst) , "r"(words) , "r"(size) , "r"(cxy) |
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[626] | 214 | : "$8","$9","$10","$11","$12","$13","$14","$15","$16","memory" ); |
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| 215 | |
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| 216 | // exit critical section |
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[1] | 217 | hal_restore_irq( save_sr ); |
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| 218 | |
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[610] | 219 | #if DEBUG_HAL_USPACE |
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[626] | 220 | cycle = (uint32_t)hal_get_cycles(); |
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| 221 | if( cycle > DEBUG_HAL_USPACE ) |
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| 222 | printk("\n[%s] thread[%x,%x] moved %d bytes / k_buf(%x,%x) -> u_buf(%x,%x) / cycle %d\n", |
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[637] | 223 | __FUNCTION__, this->process->pid, this->trdid, size, cxy, src, local_cxy, dst, cycle ); |
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[610] | 224 | #endif |
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| 225 | |
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[87] | 226 | } // end hal_copy_to_uspace() |
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| 227 | |
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[637] | 228 | ///////////////////////////////////////////////// |
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| 229 | void hal_strcpy_from_uspace( xptr_t k_dst_xp, |
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| 230 | char * u_src_ptr, |
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[407] | 231 | uint32_t size ) |
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[87] | 232 | { |
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[407] | 233 | uint32_t save_sr; |
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[637] | 234 | uint32_t src = (uint32_t)u_src_ptr; |
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| 235 | uint32_t dst = (uint32_t)GET_PTR( k_dst_xp ); |
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| 236 | uint32_t cxy = (uint32_t)GET_CXY( k_dst_xp ); |
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[87] | 237 | |
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[658] | 238 | assert( (CURRENT_THREAD->process->pid > 0), "must be called by an user thread" ); |
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| 239 | |
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[87] | 240 | hal_disable_irq( &save_sr ); |
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| 241 | |
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[425] | 242 | // loop on characters while ( (character != NUL) and (count < size ) ) |
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[637] | 243 | |
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[87] | 244 | asm volatile( |
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[407] | 245 | ".set noreorder \n" |
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[637] | 246 | |
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[654] | 247 | /* save old MMU_DEXT and set cxy in it */ |
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| 248 | "mfc2 $16, $24 \n" /* $16 <= old MMU_DEXT */ |
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| 249 | "mtc2 %3, $24 \n" /* MMU_DEXT <= cxy */ |
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[637] | 250 | |
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[407] | 251 | "move $11, %0 \n" /* $11 <= count == size */ |
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| 252 | "move $12, %1 \n" /* $12 <= u_src */ |
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| 253 | "move $13, %2 \n" /* $13 <= k_dst */ |
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[637] | 254 | "mfc2 $15, $1 \n" /* $15 <= MMU_MODE */ |
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| 255 | "ori $14, $15, 0x4 \n" /* $14 <= MMU_MODE / DTLB ON */ |
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| 256 | |
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[407] | 257 | "1: \n" |
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[87] | 258 | "mtc2 $14, $1 \n" /* MMU_MODE <= DTLB ON */ |
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[407] | 259 | "lb $10, 0($12) \n" /* read char from user space */ |
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[637] | 260 | "mtc2 $15, $1 \n" /* MMU_MODE <= DTLB OFF */ |
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[407] | 261 | "sb $10, 0($13) \n" /* store char to kernel space */ |
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[425] | 262 | "beq $10, $0, 2f \n" /* exit if char = 0 */ |
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[407] | 263 | "addi $11, $11, -1 \n" /* decrement count */ |
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| 264 | "addi $12, $12, 1 \n" /* increment u_src pointer */ |
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| 265 | "beq $11, $0, 2f \n" /* exit if count == 0 */ |
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| 266 | "addi $13, $13, 1 \n" /* increment k_src pointer */ |
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| 267 | "j 1b \n" /* jump to next iteration */ |
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| 268 | "2: \n" |
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[87] | 269 | "nop \n" |
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[637] | 270 | |
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[654] | 271 | /* restore old MMU_DEXT register */ |
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| 272 | "mtc2 $16, $24 \n" /* MMU_DEXT <= $16 */ |
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[637] | 273 | |
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[407] | 274 | ".set reorder \n" |
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| 275 | : |
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[637] | 276 | : "r"(size) , "r"(src) , "r"(dst) , "r"(cxy) |
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| 277 | : "$10","$11","$12","$13","$14","$15","$16" ); |
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[407] | 278 | |
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| 279 | hal_restore_irq( save_sr ); |
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[87] | 280 | |
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| 281 | } // hal_strcpy_from_uspace() |
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| 282 | |
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[637] | 283 | //////////////////////////////////////////////// |
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| 284 | void hal_strcpy_to_uspace( char * u_dst_ptr, |
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| 285 | xptr_t k_src_xp, |
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[407] | 286 | uint32_t size ) |
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[121] | 287 | { |
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[407] | 288 | uint32_t save_sr; |
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[637] | 289 | uint32_t dst = (uint32_t)u_dst_ptr; |
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| 290 | uint32_t src = (uint32_t)GET_PTR( k_src_xp ); |
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| 291 | uint32_t cxy = (uint32_t)GET_CXY( k_src_xp ); |
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[87] | 292 | |
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[658] | 293 | assert( (CURRENT_THREAD->process->pid > 0), "must be called by an user thread" ); |
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| 294 | |
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[87] | 295 | hal_disable_irq( &save_sr ); |
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| 296 | |
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[407] | 297 | // loop on characters while ( (character != NUL) and (count < size) ) |
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[637] | 298 | |
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[87] | 299 | asm volatile( |
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[407] | 300 | ".set noreorder \n" |
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[637] | 301 | |
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[654] | 302 | /* save old MMU_DEXT and set cxy in it */ |
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| 303 | "mfc2 $16, $24 \n" /* $16 <= old MMU_DEXT */ |
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| 304 | "mtc2 %3, $24 \n" /* MMU_DEXT <= cxy */ |
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[637] | 305 | |
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[407] | 306 | "move $11, %0 \n" /* $11 <= count == size */ |
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| 307 | "move $12, %1 \n" /* $12 <= k_src */ |
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| 308 | "move $13, %2 \n" /* $13 <= u_dst */ |
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[637] | 309 | "mfc2 $15, $1 \n" /* $15 <= MMU_MODE */ |
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| 310 | "ori $14, $15, 0x4 \n" /* $14 <= MMU_MODE modified */ |
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| 311 | |
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[407] | 312 | "1: \n" |
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| 313 | "lb $10, 0($12) \n" /* read char from kernel space */ |
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[87] | 314 | "mtc2 $14, $1 \n" /* MMU_MODE <= DTLB ON */ |
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[407] | 315 | "sb $10, 0($13) \n" /* store char to user space */ |
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[637] | 316 | "mtc2 $15, $1 \n" /* MMU_MODE <= DTLB OFF */ |
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[425] | 317 | "beq $10, $0, 2f \n" /* exit if char == 0 */ |
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[407] | 318 | "addi $11, $11, -1 \n" /* decrement count */ |
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| 319 | "addi $12, $12, 1 \n" /* increment k_src pointer */ |
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[637] | 320 | "beq $11, $0, 2f \n" /* exit if count == 0 */ |
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[407] | 321 | "addi $13, $13, 1 \n" /* increment u_src pointer */ |
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| 322 | "j 1b \n" /* jump to next iteration */ |
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| 323 | "2: \n" |
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[87] | 324 | "nop \n" |
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[637] | 325 | |
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[654] | 326 | /* restore old MMU_DEXT register */ |
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| 327 | "mtc2 $16, $24 \n" /* MMU_DEXT <= $16 */ |
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[637] | 328 | |
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[407] | 329 | ".set reorder \n" |
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| 330 | : |
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[637] | 331 | : "r"(size) , "r"(src) , "r"(dst) , "r"(cxy) |
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| 332 | : "$10","$11","$12","$13","$14","$15","$16" ); |
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[407] | 333 | |
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| 334 | hal_restore_irq( save_sr ); |
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[87] | 335 | |
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[299] | 336 | } // hal_strcpy_to_uspace() |
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[87] | 337 | |
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[1] | 338 | /////////////////////////////////////////////// |
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| 339 | uint32_t hal_strlen_from_uspace( char * u_str ) |
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| 340 | { |
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| 341 | uint32_t save_sr; |
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[407] | 342 | uint32_t count = 0; |
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[425] | 343 | uint32_t str = (uint32_t)u_str; |
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[1] | 344 | |
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[658] | 345 | assert( (CURRENT_THREAD->process->pid > 0), "must be called by an user thread" ); |
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| 346 | |
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[1] | 347 | hal_disable_irq( &save_sr ); |
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| 348 | |
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| 349 | asm volatile( |
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[407] | 350 | ".set noreorder \n" |
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[425] | 351 | "move $13, %1 \n" /* $13 <= str */ |
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[625] | 352 | "mfc2 $15, $1 \n" /* $15 <= MMU_MODE (DTLB off) */ |
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[425] | 353 | "ori $14, $15, 0x4 \n" /* $14 <= mode DTLB on */ |
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[1] | 354 | "1: \n" |
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[425] | 355 | "mtc2 $14, $1 \n" /* set DTLB on */ |
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[625] | 356 | "lb $12, 0($13) \n" /* $12 <= one byte from u_space */ |
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[425] | 357 | "mtc2 $15, $1 \n" /* set DTLB off */ |
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[1] | 358 | "addi $13, $13, 1 \n" /* increment address */ |
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[407] | 359 | "bne $12, $0, 1b \n" /* loop until NUL found */ |
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| 360 | "addi %0, %0, 1 \n" /* increment count */ |
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| 361 | ".set reorder \n" |
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| 362 | : "+r"(count) |
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| 363 | : "r"(str) |
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| 364 | : "$12","$13","$14","$15" ); |
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[1] | 365 | |
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| 366 | hal_restore_irq( save_sr ); |
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| 367 | |
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| 368 | return count; |
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| 369 | } |
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| 370 | |
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