/*
* Copyright (c) 2007 Pavel Jancik, Michal Kebrt
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup arm32mm
* @{
*/
/** @file
*/
#include <panic.h>
#include <arch/exception.h>
#include <arch/debug_print/print.h>
#include <arch/mm/page_fault.h>
#include <mm/as.h>
#include <genarch/mm/page_pt.h>
#include <arch.h>
#include <interrupt.h>
//TODO: remove in final version
static void print_istate(istate_t* istate);
static void print_istate(istate_t* istate) {
dprintf("\nIstate dump:\n");
dprintf(" r0:%X r1:%X r2:%X r3:%X\n", istate->r0, istate->r1, istate->r2, istate->r3);
dprintf(" r4:%X r5:%X r6:%X r7:%X\n", istate->r4, istate->r5, istate->r6, istate->r7);
dprintf(" r8:%X r8:%X r10:%X r11:%X\n", istate->r8, istate->r9, istate->r10, istate->r11);
dprintf(" r12:%X sp:%X lr:%X spsr:%X\n", istate->r12, istate->sp, istate->lr, istate->spsr);
}
/**
* \return Value stored in fault status register
*/
static inline fault_status_t read_fault_status_register() {
fault_status_union_t tmp;
asm volatile (
"mrc p15, 0, %0, c5, c0, 0"
: "=r"(tmp.dummy)
);
return tmp.fsr;
}
/**
* \return Virtual adress. Access on this addres caused exception
*/
static inline uintptr_t read_fault_address_register() {
uintptr_t tmp;
// Fault adress is stored in coprocessor15, register 6
asm volatile (
"mrc p15, 0, %0, c6, c0, 0"
: "=r"(tmp)
);
return tmp;
};
/** Check type of instruction
* \param i_code Instruction op code
* \return true if instruction is load or store, false otherwise
*/
static inline bool load_store_instruction(instruction_t i_code) {
// load store immediate offset
if (i_code.instr_type == 0x2) {
return true;
};
// load store register offset
if (i_code.instr_type == 0x3 && i_code.bit4 == 0) {
return true;
};
// load store multiple
if (i_code.instr_type == 0x4) {
return true;
};
// coprocessor load / strore
if (i_code.instr_type == 0x6) {
return true;
};
return false;
}
/** Check type of instruction
* \param i_code Instruction op code
* \return true if instruction is swap, false otherwise
*/
static inline bool swap_instruction(instruction_t i_code) {
// swap, swapb instruction
if (i_code.instr_type == 0x0 &&
(i_code.opcode == 0x8 || i_code.opcode == 0xA) &&
i_code.access == 0x0 && i_code.bits567 == 0x4 &&
i_code.bit4 == 1) {
return true;
};
return false;
}
/**
* Decode instruction and decide if try to read or write into memmory.
*
* \param instr_addr address of instruction which attempts access into memmory
* \param badvaddr Virtual address on which instruction tries to access
* \return type of access into memmory
* Note: return PF_ACESS_EXEC if no memmory acess
*/
//TODO: remove debug print in final version ... instead panic return PF_ACESS_EXEC
static pf_access_t get_memmory_access_type(uint32_t instr_addr, uintptr_t badvaddr) {
instruction_union_t tmp;
tmp.ip = instr_addr;
// get instruction op code
instruction_t i_code = *(tmp.instr);
// dprintf("get_instruction_memmory_access\n");
// dprintf(" instr_addr:%X\n",instr_addr);
// dprintf(" i_code:%X\n",i_code);
// dprintf(" i_code.condition:%d\n", i_code.condition);
// dprintf(" i_code.instr_type:%d\n",i_code.instr_type);
// dprintf(" i_code.opcode:%d\n",i_code.opcode);
// dprintf(" i_code.acess:%d\n", i_code.access);
// dprintf(" i_code.dummy:%d\n", i_code.dummy);
// dprintf(" i_code.bits567%d\n", i_code.bits567);
// dprintf(" i_code.bit4:%d\n", i_code.bit4);
// dprintf(" i_code.dummy1:%d\n", i_code.dummy1);
// undefined instructions ... (or special instructions)
if (i_code.condition == 0xf) {
panic("page_fault - on instruction not acessing to memmory (instr_code:%X, badvaddr:%X)",i_code, badvaddr);
return PF_ACCESS_EXEC;
};
// load store instructions
if (load_store_instruction(i_code)) {
if ( i_code.access == 1) {
return PF_ACCESS_READ;
} else {
return PF_ACCESS_WRITE;
}
};
// swap, swpb instruction
if (swap_instruction(i_code))
{
/* Swap instructions make read and write in one step.
* Type of access that caused exception have to page tables
* and access rights.
*/
//TODO: ALF!!!!! cann't use AS as is define as THE->as and THE structure is sored after stack_base of current thread
// but now ... in exception we have separate stacks <==> different stack_pointer ... so AS contains nonsence data
// same case as_page_fault .... it's nessesary to solve "stack" problem
pte_level1_t* pte = (pte_level1_t*)
pt_mapping_operations.mapping_find(AS, badvaddr);
ASSERT(pte);
/* check if read possible
* Note: Don't check PTE_READABLE because it returns 1 everytimes */
if ( !PTE_PRESENT(pte) ) {
return PF_ACCESS_READ;
}
if ( !PTE_WRITABLE(pte) ) {
return PF_ACCESS_WRITE;
}
else
// badvaddr is present readable and writeable but error occured ... why?
panic("page_fault - swap instruction, but address readable and writeable (instr_code:%X, badvaddr:%X)",i_code, badvaddr);
}
panic("page_fault - on instruction not acessing to memmory (instr_code:%X, badvaddr:%X)",i_code, badvaddr);
return PF_ACCESS_EXEC;
}
/**
* Routine that solves exception data_abourt
* ... you try to load or store value into invalid memmory address
* \param istate State of CPU when data abourt occured
* \param n number of exception
*/
//TODO: remove debug prints in final tested version
void data_abort(int n, istate_t *istate) {
fault_status_t fsr = read_fault_status_register();
uintptr_t page = read_fault_address_register();
pf_access_t access = get_memmory_access_type( istate->lr, page);
// print_istate(istate);
dprintf(" page fault : ip:%X, va:%X, status:%x(%x), access:%d\n", istate->lr, page, fsr.status,fsr, access);
/* Alf: Will be commented until stack problem will be solved ...
as_page_fault make consequent page faults*/
int ret = as_page_fault(page, access, istate);
dprintf(" as_page_fault ret:%d\n", ret);
if (ret == AS_PF_FAULT) {
fault_if_from_uspace(istate, "Page fault: %#x", page);
panic("page fault\n");
}
// TODO: Remove this ... now for testing purposes ... it's bad to test page faults in kernel, where no page faults should occures
panic("page fault ... solved\n");
}
/**
* Routine that solves exception prefetch_about
* ... you try to execute instruction on invalid address
* \param istate State of CPU when prefetch abourt occured
* \param n number of exception
*/
void prefetch_abort(int n, istate_t *istate) {
// Prefetch can be made be bkpt instruction
print_istate(istate);
dprintf(" prefetch_abourt ... instruction on adress:%x can't be fetched\n", istate->lr);
/* Alf: Will be commented until stack problem will be solved ...
as_page_fault make consequent page faults*/
int ret = as_page_fault(istate->lr, PF_ACCESS_EXEC, istate);
dprintf(" as_page_fault ret:%d\n", ret);
if (ret == AS_PF_FAULT) {
panic("page fault - instruction fetch at addr:%X\n", istate->lr);
}
panic("Prefetch abourt ... solved");
}
/** @}
*/