| 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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| 4 | * Author Alain Greiner (2016,2017,2018,2019,2020) |
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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 <hal_kernel_types.h> |
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| 25 | #include <hal_uspace.h> |
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| 26 | #include <hal_special.h> |
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| 27 | #include <hal_irqmask.h> |
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| 28 | |
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| 29 | #include <printk.h> |
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| 30 | #include <thread.h> |
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| 31 | |
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| 32 | /////////////////////////////////////////////////////////////////////////////////////// |
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| 33 | // Implementation note |
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| 34 | // It works in a critical section, as it modifies two CP2 registers: |
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| 35 | // It activates briefly the DATA_MMU by writing into the CP2_MODE register to access the |
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| 36 | // user buffer, and modifies the CP2_DEXT register to access the kernel buffer. |
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| 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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| 41 | void hal_copy_from_uspace( xptr_t k_dst_xp, |
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| 42 | void * u_src_ptr, |
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| 43 | uint32_t size ) |
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| 44 | { |
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| 45 | uint32_t save_sr; |
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| 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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| 50 | |
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| 51 | assert( __FUNCTION__, (CURRENT_THREAD->process->pid > 0), |
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| 52 | "must be called by an user thread" ); |
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| 53 | |
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| 54 | #if DEBUG_HAL_USPACE |
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| 55 | thread_t * this = CURRENT_THREAD; |
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| 56 | uint32_t cycle = (uint32_t)hal_get_cycles(); |
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| 57 | if( cycle > DEBUG_HAL_USPACE ) |
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| 58 | printk("\n[%s] thread[%x,%x] enter / %d bytes / u_buf(%x,%x) -> k_buf(%x,%x) / cycle %d\n", |
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| 59 | __FUNCTION__, this->process->pid, this->trdid, size, local_cxy, src, cxy, dst, cycle ); |
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| 60 | #endif |
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| 61 | |
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| 62 | if( (dst & 0x3) || (src & 0x3) ) words = 0; // do it all in bytes |
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| 63 | else words = size >> 2; |
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| 64 | |
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| 65 | // enter critical section |
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| 66 | hal_disable_irq( &save_sr ); |
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| 67 | |
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| 68 | asm volatile( ".set noreorder \n" |
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| 69 | |
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| 70 | /* initialise registers */ |
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| 71 | "move $8, %0 \n" /* $8 <= src */ |
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| 72 | "move $9, %1 \n" /* $9 <= dst */ |
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| 73 | "move $10, %2 \n" /* $10 <= words */ |
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| 74 | "move $11, %3 \n" /* $11 <= size */ |
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| 75 | "mfc2 $12, $1 \n" /* $12 <= old MMU_MODE */ |
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| 76 | "ori $13, $12, 0x4 \n" /* $13 <= MMU_MODE with DTLB */ |
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| 77 | |
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| 78 | /* save MMU_DEXT register */ |
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| 79 | "mfc2 $16, $24 \n" /* $16 <= old MMU_DEXT */ |
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| 80 | "mtc2 %4, $24 \n" /* MMU_DEXT <= dst_cxy */ |
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| 81 | |
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| 82 | /* transfer one word per iteration in first loop if aligned */ |
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| 83 | "move $15, $10 \n" /* $15 <= words ($15 == i) */ |
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| 84 | "1: \n" |
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| 85 | "beq $15, $0, 2f \n" /* exit loop if (i==0) */ |
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| 86 | "nop \n" |
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| 87 | "mtc2 $13, $1 \n" /* MMU_MODE <= DTLB ON */ |
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| 88 | "lw $14, 0($8) \n" /* word from user space */ |
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| 89 | "mtc2 $12, $1 \n" /* restore old MMU_MODE */ |
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| 90 | "sw $14, 0($9) \n" /* word to kernel space */ |
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| 91 | "addi $15, $15, -1 \n" /* i-- */ |
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| 92 | "addi $8, $8, 4 \n" /* src += 4 bytes */ |
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| 93 | "j 1b \n" |
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| 94 | "addi $9, $9, 4 \n" /* dst += 4 bytes */ |
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| 95 | |
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| 96 | /* transfer one byte per iteration in this second loop */ |
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| 97 | "2: \n" |
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| 98 | "sll $15, $10, 2 \n" /* $15 <= words*4 ($15 == i) */ |
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| 99 | "3: \n" |
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| 100 | "beq $15, $11, 4f \n" /* exit loop if (i == size) */ |
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| 101 | "nop \n" |
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| 102 | "mtc2 $13, $1 \n" /* MMU_MODE <= DTLB ON */ |
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| 103 | "lb $14, 0($8) \n" /* byte from user space */ |
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| 104 | "mtc2 $12, $1 \n" /* restore omd MMU_MODE */ |
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| 105 | "sb $14, 0($9) \n" /* byte to kernel space */ |
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| 106 | "addi $15, $15, 1 \n" /* i++ */ |
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| 107 | "addi $8, $8, 1 \n" /* src += 1 byte */ |
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| 108 | "j 3b \n" |
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| 109 | "addi $9, $9, 1 \n" /* dst += 1 byte */ |
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| 110 | |
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| 111 | /* restore MMU_DEXT register */ |
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| 112 | "4: \n" |
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| 113 | "mtc2 $16, $24 \n" /* MMU_DEXT <= $16 */ |
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| 114 | ".set reorder \n" |
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| 115 | : |
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| 116 | : "r"(src) , "r"(dst) , "r"(words) , "r"(size) , "r"(cxy) |
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| 117 | : "$8","$9","$10","$11","$12","$13","$14","$15","$16","memory" ); |
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| 118 | |
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| 119 | // exit critical section |
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| 120 | hal_restore_irq( save_sr ); |
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| 121 | |
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| 122 | #if DEBUG_HAL_USPACE |
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| 123 | cycle = (uint32_t)hal_get_cycles(); |
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| 124 | if( cycle > DEBUG_HAL_USPACE ) |
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| 125 | printk("\n[%s] thread[%x,%x] moved %d bytes / u_buf(%x,%x) -> k_buf(%x,%x) / cycle %d\n", |
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| 126 | __FUNCTION__, this->process->pid, this->trdid, size, local_cxy, src, cxy, dst, cycle ); |
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| 127 | #endif |
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| 128 | |
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| 129 | } // end hal_copy_from_uspace() |
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| 130 | |
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| 131 | /////////////////////////////////////////////////////////////////////////////////////// |
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| 132 | // Implementation note |
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| 133 | // It works in a critical section, as it modifies two CP2 registers: |
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| 134 | // It activates briefly the DATA_MMU by writing into the CP2_MODE register to access the |
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| 135 | // user buffer, and modifies the CP2_DEXT register to access the kernel buffer. |
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| 136 | // If the two buffers are aligned on a word boundary, it moves the data word per word |
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| 137 | // in a first loop, and moves byte per byte the remaining bytes in a second loop. |
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| 138 | // If the buffers are not word aligned, it moves all data byte per byte. |
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| 139 | /////////////////////////////////////////////////////////////////////////////////////// |
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| 140 | void hal_copy_to_uspace( void * u_dst_ptr, |
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| 141 | xptr_t k_src_xp, |
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| 142 | uint32_t size ) |
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| 143 | { |
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| 144 | uint32_t save_sr; |
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| 145 | uint32_t words; // number of words (if buffers aligned) |
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| 146 | uint32_t dst = (uint32_t)u_dst_ptr; |
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| 147 | uint32_t src = (uint32_t)GET_PTR( k_src_xp ); |
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| 148 | uint32_t cxy = (uint32_t)GET_CXY( k_src_xp ); |
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| 149 | |
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| 150 | assert( __FUNCTION__, (CURRENT_THREAD->process->pid > 0), |
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| 151 | "must be called by an user thread" ); |
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| 152 | |
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| 153 | #if DEBUG_HAL_USPACE |
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| 154 | thread_t * this = CURRENT_THREAD; |
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| 155 | uint32_t cycle = (uint32_t)hal_get_cycles(); |
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| 156 | if( cycle > DEBUG_HAL_USPACE ) |
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| 157 | printk("\n[%s] thread[%x,%x] enter / %d bytes / k_buf(%x,%x) -> u_buf(%x,%x) / cycle %d\n", |
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| 158 | __FUNCTION__, this->process->pid, this->trdid, size, cxy, src, local_cxy, dst, cycle ); |
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| 159 | #endif |
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| 160 | |
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| 161 | if( (dst & 0x3) || (src & 0x3) ) words = 0; // not aligned |
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| 162 | else words = size >> 2; |
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| 163 | |
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| 164 | // enter critical section |
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| 165 | hal_disable_irq( &save_sr ); |
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| 166 | |
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| 167 | asm volatile( ".set noreorder \n" |
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| 168 | |
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| 169 | /* initialise registers */ |
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| 170 | "move $8, %0 \n" /* $8 <= k_src */ |
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| 171 | "move $9, %1 \n" /* $9 <= u_dst */ |
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| 172 | "move $10, %2 \n" /* $10 <= words */ |
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| 173 | "move $11, %3 \n" /* $11 <= size */ |
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| 174 | "mfc2 $12, $1 \n" /* $12 <= old MMU_MODE */ |
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| 175 | "ori $13, $12, 0x4 \n" /* $13 <= MMU_MODE with DTLB */ |
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| 176 | |
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| 177 | /* save MMU_DEXT register */ |
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| 178 | "mfc2 $16, $24 \n" /* $16 <= old MMU_DEXT */ |
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| 179 | "mtc2 %4, $24 \n" /* MMU_DEXT <= cxy */ |
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| 180 | |
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| 181 | /* transfer one word per iteration in first loop if aligned */ |
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| 182 | "move $15, $10 \n" /* $15 <= words ($15 == i) */ |
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| 183 | "1: \n" |
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| 184 | "beq $15, $0, 2f \n" /* exit loop if (i==0) */ |
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| 185 | "nop \n" |
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| 186 | "lw $14, 0($8) \n" /* load from kernel space */ |
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| 187 | "mtc2 $13, $1 \n" /* MMU_MODE <= DTLB ON */ |
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| 188 | "sw $14, 0($9) \n" /* store to user space */ |
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| 189 | "mtc2 $12, $1 \n" /* restore old MMU_MODE */ |
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| 190 | "addi $15, $15, -1 \n" /* i-- */ |
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| 191 | "addi $8, $8, 4 \n" /* src += 4 bytes */ |
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| 192 | "j 1b \n" |
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| 193 | "addi $9, $9, 4 \n" /* dst += 4 bytes */ |
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| 194 | |
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| 195 | /* transfer one byte per iteration in this second loop */ |
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| 196 | "2: \n" |
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| 197 | "sll $15, $10, 2 \n" /* $15 <= words*4 ($15 == i) */ |
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| 198 | "3: \n" |
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| 199 | "beq $15, $11, 4f \n" /* exit loop if (i == size) */ |
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| 200 | "nop \n" |
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| 201 | "lb $14, 0($8) \n" /* byte from kernel space */ |
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| 202 | "mtc2 $13, $1 \n" /* MMU_MODE <= DTLB ON */ |
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| 203 | "sb $14, 0($9) \n" /* byte to user space */ |
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| 204 | "mtc2 $12, $1 \n" /* restore omd MMU_MODE */ |
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| 205 | "addi $15, $15, 1 \n" /* i++ */ |
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| 206 | "addi $8, $8, 1 \n" /* src += 1 byte */ |
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| 207 | "j 3b \n" |
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| 208 | "addi $9, $9, 1 \n" /* dst += 1 byte */ |
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| 209 | |
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| 210 | /* restore MMU_DEXT register */ |
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| 211 | "4: \n" |
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| 212 | "mtc2 $16, $24 \n" /* MMU_DEXT <= $16 */ |
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| 213 | ".set reorder \n" |
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| 214 | : |
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| 215 | : "r"(src) , "r"(dst) , "r"(words) , "r"(size) , "r"(cxy) |
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| 216 | : "$8","$9","$10","$11","$12","$13","$14","$15","$16","memory" ); |
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| 217 | |
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| 218 | // exit critical section |
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| 219 | hal_restore_irq( save_sr ); |
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| 220 | |
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| 221 | #if DEBUG_HAL_USPACE |
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| 222 | cycle = (uint32_t)hal_get_cycles(); |
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| 223 | if( cycle > DEBUG_HAL_USPACE ) |
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| 224 | printk("\n[%s] thread[%x,%x] moved %d bytes / k_buf(%x,%x) -> u_buf(%x,%x) / cycle %d\n", |
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| 225 | __FUNCTION__, this->process->pid, this->trdid, size, cxy, src, local_cxy, dst, cycle ); |
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| 226 | #endif |
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| 227 | |
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| 228 | } // end hal_copy_to_uspace() |
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| 229 | |
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| 230 | ///////////////////////////////////////////////// |
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| 231 | void hal_strcpy_from_uspace( xptr_t k_dst_xp, |
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| 232 | char * u_src_ptr, |
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| 233 | uint32_t size ) |
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| 234 | { |
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| 235 | uint32_t save_sr; |
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| 236 | uint32_t src = (uint32_t)u_src_ptr; |
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| 237 | uint32_t dst = (uint32_t)GET_PTR( k_dst_xp ); |
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| 238 | uint32_t cxy = (uint32_t)GET_CXY( k_dst_xp ); |
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| 239 | |
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| 240 | assert( __FUNCTION__, (CURRENT_THREAD->process->pid > 0), |
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| 241 | "must be called by an user thread" ); |
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| 242 | |
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| 243 | hal_disable_irq( &save_sr ); |
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| 244 | |
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| 245 | // loop on characters while ( (character != NUL) and (count < size ) ) |
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| 246 | |
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| 247 | asm volatile( |
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| 248 | ".set noreorder \n" |
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| 249 | |
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| 250 | /* save old MMU_DEXT and set cxy in it */ |
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| 251 | "mfc2 $16, $24 \n" /* $16 <= old MMU_DEXT */ |
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| 252 | "mtc2 %3, $24 \n" /* MMU_DEXT <= cxy */ |
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| 253 | |
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| 254 | "move $11, %0 \n" /* $11 <= count == size */ |
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| 255 | "move $12, %1 \n" /* $12 <= u_src */ |
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| 256 | "move $13, %2 \n" /* $13 <= k_dst */ |
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| 257 | "mfc2 $15, $1 \n" /* $15 <= MMU_MODE */ |
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| 258 | "ori $14, $15, 0x4 \n" /* $14 <= MMU_MODE / DTLB ON */ |
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| 259 | |
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| 260 | "1: \n" |
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| 261 | "mtc2 $14, $1 \n" /* MMU_MODE <= DTLB ON */ |
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| 262 | "lb $10, 0($12) \n" /* read char from user space */ |
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| 263 | "mtc2 $15, $1 \n" /* MMU_MODE <= DTLB OFF */ |
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| 264 | "sb $10, 0($13) \n" /* store char to kernel space */ |
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| 265 | "beq $10, $0, 2f \n" /* exit if char = 0 */ |
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| 266 | "addi $11, $11, -1 \n" /* decrement count */ |
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| 267 | "addi $12, $12, 1 \n" /* increment u_src pointer */ |
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| 268 | "beq $11, $0, 2f \n" /* exit if count == 0 */ |
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| 269 | "addi $13, $13, 1 \n" /* increment k_src pointer */ |
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| 270 | "j 1b \n" /* jump to next iteration */ |
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| 271 | "2: \n" |
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| 272 | "nop \n" |
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| 273 | |
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| 274 | /* restore old MMU_DEXT register */ |
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| 275 | "mtc2 $16, $24 \n" /* MMU_DEXT <= $16 */ |
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| 276 | |
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| 277 | ".set reorder \n" |
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| 278 | : |
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| 279 | : "r"(size) , "r"(src) , "r"(dst) , "r"(cxy) |
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| 280 | : "$10","$11","$12","$13","$14","$15","$16" ); |
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| 281 | |
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| 282 | hal_restore_irq( save_sr ); |
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| 283 | |
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| 284 | } // hal_strcpy_from_uspace() |
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| 285 | |
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| 286 | //////////////////////////////////////////////// |
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| 287 | void hal_strcpy_to_uspace( char * u_dst_ptr, |
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| 288 | xptr_t k_src_xp, |
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| 289 | uint32_t size ) |
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| 290 | { |
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| 291 | uint32_t save_sr; |
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| 292 | uint32_t dst = (uint32_t)u_dst_ptr; |
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| 293 | uint32_t src = (uint32_t)GET_PTR( k_src_xp ); |
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| 294 | uint32_t cxy = (uint32_t)GET_CXY( k_src_xp ); |
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| 295 | |
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| 296 | assert( __FUNCTION__, (CURRENT_THREAD->process->pid > 0), |
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| 297 | "must be called by an user thread" ); |
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| 298 | |
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| 299 | hal_disable_irq( &save_sr ); |
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| 300 | |
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| 301 | // loop on characters while ( (character != NUL) and (count < size) ) |
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| 302 | |
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| 303 | asm volatile( |
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| 304 | ".set noreorder \n" |
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| 305 | |
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| 306 | /* save old MMU_DEXT and set cxy in it */ |
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| 307 | "mfc2 $16, $24 \n" /* $16 <= old MMU_DEXT */ |
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| 308 | "mtc2 %3, $24 \n" /* MMU_DEXT <= cxy */ |
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| 309 | |
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| 310 | "move $11, %0 \n" /* $11 <= count == size */ |
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| 311 | "move $12, %1 \n" /* $12 <= k_src */ |
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| 312 | "move $13, %2 \n" /* $13 <= u_dst */ |
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| 313 | "mfc2 $15, $1 \n" /* $15 <= MMU_MODE */ |
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| 314 | "ori $14, $15, 0x4 \n" /* $14 <= MMU_MODE modified */ |
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| 315 | |
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| 316 | "1: \n" |
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| 317 | "lb $10, 0($12) \n" /* read char from kernel space */ |
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| 318 | "mtc2 $14, $1 \n" /* MMU_MODE <= DTLB ON */ |
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| 319 | "sb $10, 0($13) \n" /* store char to user space */ |
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| 320 | "mtc2 $15, $1 \n" /* MMU_MODE <= DTLB OFF */ |
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| 321 | "beq $10, $0, 2f \n" /* exit if char == 0 */ |
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| 322 | "addi $11, $11, -1 \n" /* decrement count */ |
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| 323 | "addi $12, $12, 1 \n" /* increment k_src pointer */ |
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| 324 | "beq $11, $0, 2f \n" /* exit if count == 0 */ |
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| 325 | "addi $13, $13, 1 \n" /* increment u_src pointer */ |
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| 326 | "j 1b \n" /* jump to next iteration */ |
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| 327 | "2: \n" |
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| 328 | "nop \n" |
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| 329 | |
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| 330 | /* restore old MMU_DEXT register */ |
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| 331 | "mtc2 $16, $24 \n" /* MMU_DEXT <= $16 */ |
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| 332 | |
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| 333 | ".set reorder \n" |
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| 334 | : |
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| 335 | : "r"(size) , "r"(src) , "r"(dst) , "r"(cxy) |
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| 336 | : "$10","$11","$12","$13","$14","$15","$16" ); |
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| 337 | |
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| 338 | hal_restore_irq( save_sr ); |
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| 339 | |
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| 340 | } // hal_strcpy_to_uspace() |
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| 341 | |
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| 342 | /////////////////////////////////////////////// |
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| 343 | uint32_t hal_strlen_from_uspace( char * u_str ) |
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| 344 | { |
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| 345 | uint32_t save_sr; |
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| 346 | uint32_t count = 0; |
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| 347 | uint32_t str = (uint32_t)u_str; |
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| 348 | |
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| 349 | assert( __FUNCTION__, (CURRENT_THREAD->process->pid > 0), |
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| 350 | "must be called by an user thread" ); |
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| 351 | |
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| 352 | hal_disable_irq( &save_sr ); |
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| 353 | |
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| 354 | asm volatile( |
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| 355 | ".set noreorder \n" |
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| 356 | "move $13, %1 \n" /* $13 <= str */ |
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| 357 | "mfc2 $15, $1 \n" /* $15 <= MMU_MODE (DTLB off) */ |
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| 358 | "ori $14, $15, 0x4 \n" /* $14 <= mode DTLB on */ |
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| 359 | "mtc2 $14, $1 \n" /* set DTLB on */ |
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| 360 | "1: \n" |
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| 361 | "lb $12, 0($13) \n" /* $12 <= one byte from u_space */ |
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| 362 | "beq $12, $0, 2f \n" /* exit loop when NUL found */ |
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| 363 | "addi $13, $13, 1 \n" /* increment address */ |
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| 364 | "j 1b \n" /* jump to next iteration */ |
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| 365 | "addi %0, %0, 1 \n" /* increment count if not NUL */ |
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| 366 | "2: \n" |
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| 367 | "mtc2 $15, $1 \n" /* set DTLB off */ |
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| 368 | ".set reorder \n" |
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| 369 | : "+r"(count) |
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| 370 | : "r"(str) |
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| 371 | : "$12","$13","$14","$15" ); |
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| 372 | |
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| 373 | hal_restore_irq( save_sr ); |
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| 374 | |
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| 375 | return count; |
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| 376 | } |
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| 377 | |
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