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2278 | jancik | 1 | /* |
2 | * Copyright (c) 2007 Pavel Jancik, Michal Kebrt |
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3 | * All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * |
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9 | * - Redistributions of source code must retain the above copyright |
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10 | * notice, this list of conditions and the following disclaimer. |
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11 | * - Redistributions in binary form must reproduce the above copyright |
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12 | * notice, this list of conditions and the following disclaimer in the |
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13 | * documentation and/or other materials provided with the distribution. |
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14 | * - The name of the author may not be used to endorse or promote products |
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15 | * derived from this software without specific prior written permission. |
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16 | * |
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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27 | */ |
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28 | |||
29 | /** @addtogroup arm32mm |
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30 | * @{ |
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31 | */ |
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32 | /** @file |
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2410 | stepan | 33 | * @brief Page fault related functions. |
2278 | jancik | 34 | */ |
35 | #include <panic.h> |
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36 | #include <arch/exception.h> |
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2326 | kebrt | 37 | #include <arch/debug/print.h> |
2278 | jancik | 38 | #include <arch/mm/page_fault.h> |
39 | #include <mm/as.h> |
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40 | #include <genarch/mm/page_pt.h> |
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41 | #include <arch.h> |
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2284 | stepan | 42 | #include <interrupt.h> |
2278 | jancik | 43 | |
44 | |||
2304 | kebrt | 45 | /** Returns value stored in fault status register. |
46 | * |
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2362 | jancik | 47 | * @return Value stored in CP15 fault status register (FSR). |
2304 | kebrt | 48 | */ |
49 | static inline fault_status_t read_fault_status_register(void) |
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50 | { |
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51 | fault_status_union_t fsu; |
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2278 | jancik | 52 | |
2415 | kebrt | 53 | // fault status is stored in CP15 register 5 |
2304 | kebrt | 54 | asm volatile ( |
2278 | jancik | 55 | "mrc p15, 0, %0, c5, c0, 0" |
2304 | kebrt | 56 | : "=r"(fsu.dummy) |
2278 | jancik | 57 | ); |
2304 | kebrt | 58 | return fsu.fs; |
2278 | jancik | 59 | } |
60 | |||
2304 | kebrt | 61 | |
62 | /** Returns FAR (fault address register) content. |
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63 | * |
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2362 | jancik | 64 | * @return FAR (fault address register) content (address that caused a page fault) |
2278 | jancik | 65 | */ |
2304 | kebrt | 66 | static inline uintptr_t read_fault_address_register(void) |
67 | { |
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68 | uintptr_t ret; |
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69 | |||
70 | // fault adress is stored in CP15 register 6 |
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2278 | jancik | 71 | asm volatile ( |
72 | "mrc p15, 0, %0, c6, c0, 0" |
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2304 | kebrt | 73 | : "=r"(ret) |
2278 | jancik | 74 | ); |
2304 | kebrt | 75 | return ret; |
76 | } |
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2278 | jancik | 77 | |
2304 | kebrt | 78 | |
2415 | kebrt | 79 | /** Decides whether the instruction is load/store or not. |
2304 | kebrt | 80 | * |
2362 | jancik | 81 | * @param instr Instruction |
2304 | kebrt | 82 | * |
2362 | jancik | 83 | * @return true when instruction is load/store, false otherwise |
2278 | jancik | 84 | */ |
2304 | kebrt | 85 | static inline bool is_load_store_instruction(instruction_t instr) |
86 | { |
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87 | // load store immediate offset |
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88 | if (instr.type == 0x2) { |
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2278 | jancik | 89 | return true; |
2304 | kebrt | 90 | } |
2278 | jancik | 91 | |
2304 | kebrt | 92 | // load store register offset |
93 | if (instr.type == 0x3 && instr.bit4 == 0) { |
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2278 | jancik | 94 | return true; |
2304 | kebrt | 95 | } |
2278 | jancik | 96 | |
2304 | kebrt | 97 | // load store multiple |
98 | if (instr.type == 0x4) { |
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2278 | jancik | 99 | return true; |
2304 | kebrt | 100 | } |
2278 | jancik | 101 | |
2304 | kebrt | 102 | // coprocessor load/store |
103 | if (instr.type == 0x6) { |
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2278 | jancik | 104 | return true; |
2304 | kebrt | 105 | } |
2278 | jancik | 106 | |
107 | return false; |
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108 | } |
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109 | |||
2304 | kebrt | 110 | |
111 | /** Decides whether the instructions is swap or not. |
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112 | * |
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2362 | jancik | 113 | * @param instr Instruction |
2304 | kebrt | 114 | * |
2362 | jancik | 115 | * @return true when instruction is swap, false otherwise |
2278 | jancik | 116 | */ |
2304 | kebrt | 117 | static inline bool is_swap_instruction(instruction_t instr) |
118 | { |
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2278 | jancik | 119 | // swap, swapb instruction |
2304 | kebrt | 120 | if (instr.type == 0x0 && |
121 | (instr.opcode == 0x8 || instr.opcode == 0xa) && |
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122 | instr.access == 0x0 && instr.bits567 == 0x4 && instr.bit4 == 1) { |
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2278 | jancik | 123 | return true; |
2304 | kebrt | 124 | } |
2278 | jancik | 125 | |
126 | return false; |
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127 | } |
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128 | |||
129 | |||
2304 | kebrt | 130 | /** Decides whether read or write into memory is requested. |
2278 | jancik | 131 | * |
2415 | kebrt | 132 | * @param instr_addr Address of instruction which tries to access memory. |
133 | * @param badvaddr Virtual address the instruction tries to access. |
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2304 | kebrt | 134 | * |
2418 | kebrt | 135 | * @return Type of access into memory, PF_ACCESS_EXEC if no memory access is requested. |
2278 | jancik | 136 | */ |
2304 | kebrt | 137 | static pf_access_t get_memory_access_type(uint32_t instr_addr, uintptr_t badvaddr) |
138 | { |
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139 | instruction_union_t instr_union; |
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140 | instr_union.pc = instr_addr; |
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2278 | jancik | 141 | |
2304 | kebrt | 142 | instruction_t instr = *(instr_union.instr); |
2278 | jancik | 143 | |
2304 | kebrt | 144 | // undefined instructions |
145 | if (instr.condition == 0xf) { |
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2415 | kebrt | 146 | panic("page_fault - instruction doesn't access memory (instr_code: %x, badvaddr:%x)", |
2304 | kebrt | 147 | instr, badvaddr); |
2278 | jancik | 148 | return PF_ACCESS_EXEC; |
2304 | kebrt | 149 | } |
2278 | jancik | 150 | |
151 | // load store instructions |
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2304 | kebrt | 152 | if (is_load_store_instruction(instr)) { |
153 | if (instr.access == 1) { |
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2278 | jancik | 154 | return PF_ACCESS_READ; |
155 | } else { |
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156 | return PF_ACCESS_WRITE; |
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157 | } |
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2304 | kebrt | 158 | } |
2278 | jancik | 159 | |
160 | // swap, swpb instruction |
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2304 | kebrt | 161 | if (is_swap_instruction(instr)) { |
2415 | kebrt | 162 | return PF_ACCESS_WRITE; |
2278 | jancik | 163 | } |
2304 | kebrt | 164 | |
2415 | kebrt | 165 | panic("page_fault - instruction doesn't access memory (instr_code: %x, badvaddr:%x)", |
2304 | kebrt | 166 | instr, badvaddr); |
167 | |||
2278 | jancik | 168 | return PF_ACCESS_EXEC; |
169 | } |
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170 | |||
2304 | kebrt | 171 | /** Handles "data abort" exception (load or store at invalid address). |
172 | * |
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2415 | kebrt | 173 | * @param exc_no Exception number. |
174 | * @param istate CPU state when exception occured. |
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2278 | jancik | 175 | */ |
2304 | kebrt | 176 | void data_abort(int exc_no, istate_t *istate) |
177 | { |
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178 | fault_status_t fsr = read_fault_status_register(); |
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179 | uintptr_t badvaddr = read_fault_address_register(); |
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2278 | jancik | 180 | |
2304 | kebrt | 181 | pf_access_t access = get_memory_access_type(istate->pc, badvaddr); |
182 | |||
183 | int ret = as_page_fault(badvaddr, access, istate); |
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2278 | jancik | 184 | |
2304 | kebrt | 185 | if (ret == AS_PF_FAULT) { |
186 | print_istate(istate); |
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187 | dprintf("page fault - pc: %x, va: %x, status: %x(%x), access:%d\n", |
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188 | istate->pc, badvaddr, fsr.status, fsr, access); |
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2278 | jancik | 189 | |
2304 | kebrt | 190 | fault_if_from_uspace(istate, "Page fault: %#x", badvaddr); |
2298 | stepan | 191 | panic("page fault\n"); |
2304 | kebrt | 192 | } |
2278 | jancik | 193 | } |
194 | |||
2304 | kebrt | 195 | /** Handles "prefetch abort" exception (instruction couldn't be executed). |
196 | * |
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2415 | kebrt | 197 | * @param exc_no Exception number. |
198 | * @param istate CPU state when exception occured. |
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2278 | jancik | 199 | */ |
2304 | kebrt | 200 | void prefetch_abort(int exc_no, istate_t *istate) |
201 | { |
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2298 | stepan | 202 | int ret = as_page_fault(istate->pc, PF_ACCESS_EXEC, istate); |
2278 | jancik | 203 | |
2304 | kebrt | 204 | if (ret == AS_PF_FAULT) { |
205 | dprintf("prefetch_abort\n"); |
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206 | print_istate(istate); |
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207 | panic("page fault - prefetch_abort at address: %x\n", istate->pc); |
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208 | } |
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2278 | jancik | 209 | } |
210 | |||
211 | /** @} |
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212 | */ |
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213 |