WebSVN – HelenOS – Diff – /branches/arm/kernel/arch/arm32/src/mm/page_fault.c


/*
 * 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
 *  @brief Page fault related functions.
 */
#include <panic.h>
#include <arch/exception.h>
#include <arch/debug/print.h>
#include <arch/mm/page_fault.h>
#include <mm/as.h>
#include <genarch/mm/page_pt.h>
#include <arch.h>
#include <interrupt.h>
 
 
/** Returns value stored in fault status register.
 
 *
 *  @return Value stored in CP15 fault status register (FSR).
 */
static inline fault_status_t read_fault_status_register(void)
{
    fault_status_union_t fsu;
 
    // fault status is stored in CP15 register 5
    asm volatile (
        "mrc p15, 0, %0, c5, c0, 0"
        : "=r"(fsu.dummy)
    );
    return fsu.fs;
}
 
 
/** Returns FAR (fault address register) content.
 *
 *  @return FAR (fault address register) content (address that caused a page fault)
 */
static inline uintptr_t read_fault_address_register(void)
{
    uintptr_t ret;
   
    // fault adress is stored in CP15 register 6
    asm volatile (
        "mrc p15, 0, %0, c6, c0, 0"
        : "=r"(ret)
    );
    return ret;
}
 
 
/** Decides whether the instruction is load/store or not.
 *
 * @param instr Instruction
 *
 * @return true when instruction is load/store, false otherwise
 */
static inline bool is_load_store_instruction(instruction_t instr)
{
    // load store immediate offset
    if (instr.type == 0x2) {
        return true;
    }
 
    // load store register offset
    if (instr.type == 0x3 && instr.bit4 == 0) {
        return true;
    }
 
    // load store multiple
    if (instr.type == 0x4) {
        return true;
    }
 
    // coprocessor load/store
    if (instr.type == 0x6) {
        return true;
    }
 
    return false;
}
 
 
/** Decides whether the instructions is swap or not.
 *
 * @param instr Instruction
 *
 * @return true when instruction is swap, false otherwise
 */
static inline bool is_swap_instruction(instruction_t instr)
{
    // swap, swapb instruction
    if (instr.type == 0x0 &&
        (instr.opcode == 0x8 || instr.opcode == 0xa) &&
        instr.access == 0x0 && instr.bits567 == 0x4 && instr.bit4 == 1) {
        return true;
    }
 
    return false;
}
 
 
/** Decides whether read or write into memory is requested.
 *
 * @param instr_addr   Address of instruction which tries to access memory.
 * @param badvaddr     Virtual address the instruction tries to access.
 *
 
 * @return Type of access into memmory, #PF_ACCESS_EXEC if no memory access is requested.
 */
static pf_access_t get_memory_access_type(uint32_t instr_addr, uintptr_t badvaddr)
{  
    instruction_union_t instr_union;
    instr_union.pc = instr_addr;
 
    instruction_t instr = *(instr_union.instr);
 
    // undefined instructions
    if (instr.condition == 0xf) {
        panic("page_fault - instruction doesn't access memory (instr_code: %x, badvaddr:%x)",
            instr, badvaddr);
        return PF_ACCESS_EXEC;
    }
 
    // load store instructions
    if (is_load_store_instruction(instr)) {
        if (instr.access == 1) {
            return PF_ACCESS_READ;
        } else {
            return PF_ACCESS_WRITE;
        }
    }
 
    // swap, swpb instruction
    if (is_swap_instruction(instr)) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
        return PF_ACCESS_WRITE;
 
 
 
 
 
    }
 
    panic("page_fault - instruction doesn't access memory (instr_code: %x, badvaddr:%x)",
        instr, badvaddr);
 
    return PF_ACCESS_EXEC;
}
 
/** Handles "data abort" exception (load or store at invalid address).
 *
 * @param exc_no    Exception number.
 * @param istate    CPU state when exception occured.
 */
void data_abort(int exc_no, istate_t *istate)
{
    fault_status_t fsr = read_fault_status_register();
    uintptr_t badvaddr = read_fault_address_register();
 
    pf_access_t access = get_memory_access_type(istate->pc, badvaddr);
   
    int ret = as_page_fault(badvaddr, access, istate);
 
    if (ret == AS_PF_FAULT) {
        print_istate(istate);
        dprintf("page fault - pc: %x, va: %x, status: %x(%x), access:%d\n",
            istate->pc, badvaddr, fsr.status, fsr, access);
 
        fault_if_from_uspace(istate, "Page fault: %#x", badvaddr);
        panic("page fault\n");
    }
}
 
/** Handles "prefetch abort" exception (instruction couldn't be executed).
 *
 * @param exc_no    Exception number.
 * @param istate    CPU state when exception occured.
 */
void prefetch_abort(int exc_no, istate_t *istate)
{
    int ret = as_page_fault(istate->pc, PF_ACCESS_EXEC, istate);
 
    if (ret == AS_PF_FAULT) {
        dprintf("prefetch_abort\n");
        print_istate(istate);
        panic("page fault - prefetch_abort at address: %x\n", istate->pc);
    }
}
 
/** @}
 */
 
 

Rev 2410	Rev 2415
1	/*	1	/*
2	* Copyright (c) 2007 Pavel Jancik, Michal Kebrt	2	* Copyright (c) 2007 Pavel Jancik, Michal Kebrt
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	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	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.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	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	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	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	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	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	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.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup arm32mm	29	/** @addtogroup arm32mm
30	* @{	30	* @{
31	*/	31	*/
32	/** @file	32	/** @file
33	* @brief Page fault related functions.	33	* @brief Page fault related functions.
34	*/	34	*/
35	#include <panic.h>	35	#include <panic.h>
36	#include <arch/exception.h>	36	#include <arch/exception.h>
37	#include <arch/debug/print.h>	37	#include <arch/debug/print.h>
38	#include <arch/mm/page_fault.h>	38	#include <arch/mm/page_fault.h>
39	#include <mm/as.h>	39	#include <mm/as.h>
40	#include <genarch/mm/page_pt.h>	40	#include <genarch/mm/page_pt.h>
41	#include <arch.h>	41	#include <arch.h>
42	#include <interrupt.h>	42	#include <interrupt.h>
43		43
44		44
45	/** Returns value stored in fault status register.	45	/** Returns value stored in fault status register.
46	* FSR contain reason of page fault	-
47	*	46	*
48	* @return Value stored in CP15 fault status register (FSR).	47	* @return Value stored in CP15 fault status register (FSR).
49	*/	48	*/
50	static inline fault_status_t read_fault_status_register(void)	49	static inline fault_status_t read_fault_status_register(void)
51	{	50	{
52	fault_status_union_t fsu;	51	fault_status_union_t fsu;
53		52
54	// fault adress is stored in CP15 register 5	53	// fault status is stored in CP15 register 5
55	asm volatile (	54	asm volatile (
56	"mrc p15, 0, %0, c5, c0, 0"	55	"mrc p15, 0, %0, c5, c0, 0"
57	: "=r"(fsu.dummy)	56	: "=r"(fsu.dummy)
58	);	57	);
59	return fsu.fs;	58	return fsu.fs;
60	}	59	}
61		60
62		61
63	/** Returns FAR (fault address register) content.	62	/** Returns FAR (fault address register) content.
64	*	63	*
65	* @return FAR (fault address register) content (address that caused a page fault)	64	* @return FAR (fault address register) content (address that caused a page fault)
66	*/	65	*/
67	static inline uintptr_t read_fault_address_register(void)	66	static inline uintptr_t read_fault_address_register(void)
68	{	67	{
69	uintptr_t ret;	68	uintptr_t ret;
70		69
71	// fault adress is stored in CP15 register 6	70	// fault adress is stored in CP15 register 6
72	asm volatile (	71	asm volatile (
73	"mrc p15, 0, %0, c6, c0, 0"	72	"mrc p15, 0, %0, c6, c0, 0"
74	: "=r"(ret)	73	: "=r"(ret)
75	);	74	);
76	return ret;	75	return ret;
77	}	76	}
78		77
79		78
80	/** Decides whether the instructions is load/store or not.	79	/** Decides whether the instruction is load/store or not.
81	*	80	*
82	* @param instr Instruction	81	* @param instr Instruction
83	*	82	*
84	* @return true when instruction is load/store, false otherwise	83	* @return true when instruction is load/store, false otherwise
85	*/	84	*/
86	static inline bool is_load_store_instruction(instruction_t instr)	85	static inline bool is_load_store_instruction(instruction_t instr)
87	{	86	{
88	// load store immediate offset	87	// load store immediate offset
89	if (instr.type == 0x2) {	88	if (instr.type == 0x2) {
90	return true;	89	return true;
91	}	90	}
92		91
93	// load store register offset	92	// load store register offset
94	if (instr.type == 0x3 && instr.bit4 == 0) {	93	if (instr.type == 0x3 && instr.bit4 == 0) {
95	return true;	94	return true;
96	}	95	}
97		96
98	// load store multiple	97	// load store multiple
99	if (instr.type == 0x4) {	98	if (instr.type == 0x4) {
100	return true;	99	return true;
101	}	100	}
102		101
103	// coprocessor load/store	102	// coprocessor load/store
104	if (instr.type == 0x6) {	103	if (instr.type == 0x6) {
105	return true;	104	return true;
106	}	105	}
107		106
108	return false;	107	return false;
109	}	108	}
110		109
111		110
112	/** Decides whether the instructions is swap or not.	111	/** Decides whether the instructions is swap or not.
113	*	112	*
114	* @param instr Instruction	113	* @param instr Instruction
115	*	114	*
116	* @return true when instruction is swap, false otherwise	115	* @return true when instruction is swap, false otherwise
117	*/	116	*/
118	static inline bool is_swap_instruction(instruction_t instr)	117	static inline bool is_swap_instruction(instruction_t instr)
119	{	118	{
120	// swap, swapb instruction	119	// swap, swapb instruction
121	if (instr.type == 0x0 &&	120	if (instr.type == 0x0 &&
122	(instr.opcode == 0x8 \|\| instr.opcode == 0xa) &&	121	(instr.opcode == 0x8 \|\| instr.opcode == 0xa) &&
123	instr.access == 0x0 && instr.bits567 == 0x4 && instr.bit4 == 1) {	122	instr.access == 0x0 && instr.bits567 == 0x4 && instr.bit4 == 1) {
124	return true;	123	return true;
125	}	124	}
126		125
127	return false;	126	return false;
128	}	127	}
129		128
130		129
131	/** Decides whether read or write into memory is requested.	130	/** Decides whether read or write into memory is requested.
132	*	131	*
133	* @param instr_addr Address of instruction which tries to access memory	132	* @param instr_addr Address of instruction which tries to access memory.
134	* @param badvaddr Virtual address the instruction tries to access	133	* @param badvaddr Virtual address the instruction tries to access.
135	*	134	*
136	* @return Type of access into memmory	-
137	* Note: Returns #PF_ACCESS_EXEC if no memory access is requested	135	* @return Type of access into memmory, #PF_ACCESS_EXEC if no memory access is requested.
138	*/	136	*/
139	static pf_access_t get_memory_access_type(uint32_t instr_addr, uintptr_t badvaddr)	137	static pf_access_t get_memory_access_type(uint32_t instr_addr, uintptr_t badvaddr)
140	{	138	{
141	instruction_union_t instr_union;	139	instruction_union_t instr_union;
142	instr_union.pc = instr_addr;	140	instr_union.pc = instr_addr;
143		141
144	instruction_t instr = *(instr_union.instr);	142	instruction_t instr = *(instr_union.instr);
145		143
146	// undefined instructions	144	// undefined instructions
147	if (instr.condition == 0xf) {	145	if (instr.condition == 0xf) {
148	panic("page_fault - instruction not access memmory (instr_code: %x, badvaddr:%x)",	146	panic("page_fault - instruction doesn't access memory (instr_code: %x, badvaddr:%x)",
149	instr, badvaddr);	147	instr, badvaddr);
150	return PF_ACCESS_EXEC;	148	return PF_ACCESS_EXEC;
151	}	149	}
152		150
153	// load store instructions	151	// load store instructions
154	if (is_load_store_instruction(instr)) {	152	if (is_load_store_instruction(instr)) {
155	if (instr.access == 1) {	153	if (instr.access == 1) {
156	return PF_ACCESS_READ;	154	return PF_ACCESS_READ;
157	} else {	155	} else {
158	return PF_ACCESS_WRITE;	156	return PF_ACCESS_WRITE;
159	}	157	}
160	}	158	}
161		159
162	// swap, swpb instruction	160	// swap, swpb instruction
163	if (is_swap_instruction(instr)) {	161	if (is_swap_instruction(instr)) {
164	/* Swap instructions make read and write in one step.	-
165	* Type of access that caused exception have to page tables	-
166	* and access rights.	-
167	*/	-
168		-
169	pte_level1_t* pte = (pte_level1_t*)	-
170	pt_mapping_operations.mapping_find(AS, badvaddr);	-
171		-
172	if ( pte == NULL ) {	-
173	return PF_ACCESS_READ;	-
174	}	-
175		-
176	/* check if read possible	-
177	* Note: Don't check PTE_READABLE because it returns 1 everytimes */	-
178	if ( !PTE_PRESENT(pte) ) {	-
179	return PF_ACCESS_READ;	-
180	}	-
181		-
182	if ( !PTE_WRITABLE(pte) ) {	-
183	return PF_ACCESS_WRITE;	162	return PF_ACCESS_WRITE;
184	} else {	-
185	// badvaddr is present readable and writeable but error occured ... why?	-
186	panic("page_fault - swap instruction, but address readable and writeable"	-
187	"(instr_code:%X, badvaddr:%X)", instr, badvaddr);	-
188	}	-
189	}	163	}
190		164
191	panic("page_fault - instruction not access memory (instr_code: %x, badvaddr:%x)",	165	panic("page_fault - instruction doesn't access memory (instr_code: %x, badvaddr:%x)",
192	instr, badvaddr);	166	instr, badvaddr);
193		167
194	return PF_ACCESS_EXEC;	168	return PF_ACCESS_EXEC;
195	}	169	}
196		170
197	/** Handles "data abort" exception (load or store at invalid address).	171	/** Handles "data abort" exception (load or store at invalid address).
198	*	172	*
199	* @param exc_no exception number	173	* @param exc_no Exception number.
200	* @param istate CPU state when exception occured	174	* @param istate CPU state when exception occured.
201	*/	175	*/
202	void data_abort(int exc_no, istate_t *istate)	176	void data_abort(int exc_no, istate_t *istate)
203	{	177	{
204	fault_status_t fsr = read_fault_status_register();	178	fault_status_t fsr = read_fault_status_register();
205	uintptr_t badvaddr = read_fault_address_register();	179	uintptr_t badvaddr = read_fault_address_register();
206		180
207	pf_access_t access = get_memory_access_type(istate->pc, badvaddr);	181	pf_access_t access = get_memory_access_type(istate->pc, badvaddr);
208		182
209	int ret = as_page_fault(badvaddr, access, istate);	183	int ret = as_page_fault(badvaddr, access, istate);
210		184
211	if (ret == AS_PF_FAULT) {	185	if (ret == AS_PF_FAULT) {
212	print_istate(istate);	186	print_istate(istate);
213	dprintf("page fault - pc: %x, va: %x, status: %x(%x), access:%d\n",	187	dprintf("page fault - pc: %x, va: %x, status: %x(%x), access:%d\n",
214	istate->pc, badvaddr, fsr.status, fsr, access);	188	istate->pc, badvaddr, fsr.status, fsr, access);
215		189
216	fault_if_from_uspace(istate, "Page fault: %#x", badvaddr);	190	fault_if_from_uspace(istate, "Page fault: %#x", badvaddr);
217	panic("page fault\n");	191	panic("page fault\n");
218	}	192	}
219	}	193	}
220		194
221	/** Handles "prefetch abort" exception (instruction couldn't be executed).	195	/** Handles "prefetch abort" exception (instruction couldn't be executed).
222	*	196	*
223	* @param exc_no exception number	197	* @param exc_no Exception number.
224	* @param istate CPU state when exception occured	198	* @param istate CPU state when exception occured.
225	*/	199	*/
226	void prefetch_abort(int exc_no, istate_t *istate)	200	void prefetch_abort(int exc_no, istate_t *istate)
227	{	201	{
228	int ret = as_page_fault(istate->pc, PF_ACCESS_EXEC, istate);	202	int ret = as_page_fault(istate->pc, PF_ACCESS_EXEC, istate);
229		203
230	if (ret == AS_PF_FAULT) {	204	if (ret == AS_PF_FAULT) {
231	dprintf("prefetch_abort\n");	205	dprintf("prefetch_abort\n");
232	print_istate(istate);	206	print_istate(istate);
233	panic("page fault - prefetch_abort at address: %x\n", istate->pc);	207	panic("page fault - prefetch_abort at address: %x\n", istate->pc);
234	}	208	}
235	}	209	}
236		210
237	/** @}	211	/** @}
238	*/	212	*/
239		213
240		214

Subversion Repositories HelenOS

(root)/branches/arm/kernel/arch/arm32/src/mm/page_fault.c – Rev 2410 → 2415