Subversion Repositories HelenOS

Rev

Rev 4018 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2464 jermar 1
/*
2
 * Copyright (c) 2007 Pavel Jancik, Michal Kebrt
3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
29
/** @addtogroup arm32mm
30
 * @{
31
 */
32
/** @file
33
 *  @brief Page fault related functions.
34
 */
35
#include <panic.h>
36
#include <arch/exception.h>
37
#include <arch/mm/page_fault.h>
38
#include <mm/as.h>
39
#include <genarch/mm/page_pt.h>
40
#include <arch.h>
41
#include <interrupt.h>
3094 svoboda 42
#include <print.h>
2464 jermar 43
 
44
/** Returns value stored in fault status register.
45
 *
46
 *  @return Value stored in CP15 fault status register (FSR).
47
 */
48
static inline fault_status_t read_fault_status_register(void)
49
{
50
    fault_status_union_t fsu;
4018 decky 51
 
2464 jermar 52
    /* fault status is stored in CP15 register 5 */
53
    asm volatile (
4018 decky 54
        "mrc p15, 0, %[dummy], c5, c0, 0"
55
        : [dummy] "=r" (fsu.dummy)
2464 jermar 56
    );
4018 decky 57
 
2464 jermar 58
    return fsu.fs;
59
}
60
 
61
/** Returns FAR (fault address register) content.
62
 *
63
 * @return FAR (fault address register) content (address that caused a page
4018 decky 64
 *         fault)
2464 jermar 65
 */
66
static inline uintptr_t read_fault_address_register(void)
67
{
68
    uintptr_t ret;
4018 decky 69
 
2464 jermar 70
    /* fault adress is stored in CP15 register 6 */
71
    asm volatile (
4018 decky 72
        "mrc p15, 0, %[ret], c6, c0, 0"
73
        : [ret] "=r" (ret)
2464 jermar 74
    );
4018 decky 75
 
2464 jermar 76
    return ret;
77
}
78
 
79
/** Decides whether the instruction is load/store or not.
80
 *
81
 * @param instr Instruction
82
 *
83
 * @return true when instruction is load/store, false otherwise
4018 decky 84
 *
2464 jermar 85
 */
86
static inline bool is_load_store_instruction(instruction_t instr)
87
{
88
    /* load store immediate offset */
4018 decky 89
    if (instr.type == 0x2)
2464 jermar 90
        return true;
4018 decky 91
 
2464 jermar 92
    /* load store register offset */
4018 decky 93
    if ((instr.type == 0x3) && (instr.bit4 == 0))
2464 jermar 94
        return true;
4018 decky 95
 
2464 jermar 96
    /* load store multiple */
4018 decky 97
    if (instr.type == 0x4)
2464 jermar 98
        return true;
4018 decky 99
 
2464 jermar 100
    /* oprocessor load/store */
4018 decky 101
    if (instr.type == 0x6)
2464 jermar 102
        return true;
4018 decky 103
 
2464 jermar 104
    return false;
105
}
106
 
107
/** Decides whether the instruction is swap or not.
108
 *
109
 * @param instr Instruction
110
 *
111
 * @return true when instruction is swap, false otherwise
112
 */
113
static inline bool is_swap_instruction(instruction_t instr)
114
{
115
    /* swap, swapb instruction */
4018 decky 116
    if ((instr.type == 0x0) &&
117
        ((instr.opcode == 0x8) || (instr.opcode == 0xa)) &&
118
        (instr.access == 0x0) && (instr.bits567 == 0x4) && (instr.bit4 == 1))
2464 jermar 119
        return true;
4018 decky 120
 
2464 jermar 121
    return false;
122
}
123
 
124
/** Decides whether read or write into memory is requested.
125
 *
126
 * @param instr_addr   Address of instruction which tries to access memory.
127
 * @param badvaddr     Virtual address the instruction tries to access.
128
 *
129
 * @return Type of access into memory, PF_ACCESS_EXEC if no memory access is
130
 *     requested.
131
 */
132
static pf_access_t get_memory_access_type(uint32_t instr_addr,
133
    uintptr_t badvaddr)
134
{
135
    instruction_union_t instr_union;
136
    instr_union.pc = instr_addr;
137
 
138
    instruction_t instr = *(instr_union.instr);
139
 
140
    /* undefined instructions */
141
    if (instr.condition == 0xf) {
3790 svoboda 142
        panic("page_fault - instruction does not access memory "
143
            "(instr_code: %x, badvaddr:%x).", instr, badvaddr);
2464 jermar 144
        return PF_ACCESS_EXEC;
145
    }
146
 
147
    /* load store instructions */
148
    if (is_load_store_instruction(instr)) {
149
        if (instr.access == 1) {
150
            return PF_ACCESS_READ;
151
        } else {
152
            return PF_ACCESS_WRITE;
153
        }
154
    }
155
 
156
    /* swap, swpb instruction */
157
    if (is_swap_instruction(instr)) {
158
        return PF_ACCESS_WRITE;
159
    }
160
 
161
    panic("page_fault - instruction doesn't access memory "
3790 svoboda 162
        "(instr_code: %x, badvaddr:%x).", instr, badvaddr);
2464 jermar 163
 
164
    return PF_ACCESS_EXEC;
165
}
166
 
167
/** Handles "data abort" exception (load or store at invalid address).
168
 *
169
 * @param exc_no    Exception number.
170
 * @param istate    CPU state when exception occured.
171
 */
172
void data_abort(int exc_no, istate_t *istate)
173
{
2772 jermar 174
    fault_status_t fsr __attribute__ ((unused)) =
175
        read_fault_status_register();
2464 jermar 176
    uintptr_t badvaddr = read_fault_address_register();
177
 
178
    pf_access_t access = get_memory_access_type(istate->pc, badvaddr);
179
 
180
    int ret = as_page_fault(badvaddr, access, istate);
181
 
182
    if (ret == AS_PF_FAULT) {
183
        print_istate(istate);
4117 decky 184
        printf("page fault - pc: %x, va: %x, status: %x(%x), "
2464 jermar 185
            "access:%d\n", istate->pc, badvaddr, fsr.status, fsr,
186
            access);
4117 decky 187
 
3790 svoboda 188
        fault_if_from_uspace(istate, "Page fault: %#x.", badvaddr);
189
        panic("Page fault.");
2464 jermar 190
    }
191
}
192
 
193
/** Handles "prefetch abort" exception (instruction couldn't be executed).
194
 *
195
 * @param exc_no    Exception number.
196
 * @param istate    CPU state when exception occured.
197
 */
198
void prefetch_abort(int exc_no, istate_t *istate)
199
{
200
    int ret = as_page_fault(istate->pc, PF_ACCESS_EXEC, istate);
201
 
202
    if (ret == AS_PF_FAULT) {
4117 decky 203
        printf("prefetch_abort\n");
2464 jermar 204
        print_istate(istate);
3790 svoboda 205
        panic("page fault - prefetch_abort at address: %x.",
2464 jermar 206
            istate->pc);
207
    }
208
}
209
 
210
/** @}
211
 */