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1/*
2 * linux/arch/unicore32/lib/backtrace.S
3 *
4 * Code specific to PKUnity SoC and UniCore ISA
5 *
6 * Copyright (C) 2001-2010 GUAN Xue-tao
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <linux/linkage.h>
13#include <asm/assembler.h>
14 .text
15
16@ fp is 0 or stack frame
17
18#define frame v4
19#define sv_fp v5
20#define sv_pc v6
21#define offset v8
22
23ENTRY(__backtrace)
24 mov r0, fp
25
26ENTRY(c_backtrace)
27
28#if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK)
29 mov pc, lr
30ENDPROC(__backtrace)
31ENDPROC(c_backtrace)
32#else
33 stm.w (v4 - v8, lr), [sp-] @ Save an extra register
34 @ so we have a location...
35 mov.a frame, r0 @ if frame pointer is zero
36 beq no_frame @ we have no stack frames
37
381: stm.w (pc), [sp-] @ calculate offset of PC stored
39 ldw.w r0, [sp]+, #4 @ by stmfd for this CPU
40 adr r1, 1b
41 sub offset, r0, r1
42
43/*
44 * Stack frame layout:
45 * optionally saved caller registers (r4 - r10)
46 * saved fp
47 * saved sp
48 * saved lr
49 * frame => saved pc
50 * optionally saved arguments (r0 - r3)
51 * saved sp => <next word>
52 *
53 * Functions start with the following code sequence:
54 * mov ip, sp
55 * stm.w (r0 - r3), [sp-] (optional)
56 * corrected pc => stm.w sp, (..., fp, ip, lr, pc)
57 */
58for_each_frame:
59
601001: ldw sv_pc, [frame+], #0 @ get saved pc
611002: ldw sv_fp, [frame+], #-12 @ get saved fp
62
63 sub sv_pc, sv_pc, offset @ Correct PC for prefetching
64
651003: ldw r2, [sv_pc+], #-4 @ if stmfd sp, {args} exists,
66 ldw r3, .Ldsi+4 @ adjust saved 'pc' back one
67 cxor.a r3, r2 >> #14 @ instruction
68 beq 201f
69 sub r0, sv_pc, #4 @ allow for mov
70 b 202f
71201:
72 sub r0, sv_pc, #8 @ allow for mov + stmia
73202:
74 ldw r1, [frame+], #-4 @ get saved lr
75 mov r2, frame
76 b.l dump_backtrace_entry
77
78 ldw r1, [sv_pc+], #-4 @ if stmfd sp, {args} exists,
79 ldw r3, .Ldsi+4
80 cxor.a r3, r1 >> #14
81 bne 1004f
82 ldw r0, [frame+], #-8 @ get sp
83 sub r0, r0, #4 @ point at the last arg
84 b.l .Ldumpstm @ dump saved registers
85
861004: ldw r1, [sv_pc+], #0 @ if stmfd {, fp, ip, lr, pc}
87 ldw r3, .Ldsi @ instruction exists,
88 cxor.a r3, r1 >> #14
89 bne 201f
90 sub r0, frame, #16
91 b.l .Ldumpstm @ dump saved registers
92201:
93 cxor.a sv_fp, #0 @ zero saved fp means
94 beq no_frame @ no further frames
95
96 csub.a sv_fp, frame @ next frame must be
97 mov frame, sv_fp @ above the current frame
98 bua for_each_frame
99
1001006: adr r0, .Lbad
101 mov r1, frame
102 b.l printk
103no_frame: ldm.w (v4 - v8, pc), [sp]+
104ENDPROC(__backtrace)
105ENDPROC(c_backtrace)
106
107 .pushsection __ex_table,"a"
108 .align 3
109 .long 1001b, 1006b
110 .long 1002b, 1006b
111 .long 1003b, 1006b
112 .long 1004b, 1006b
113 .popsection
114
115#define instr v4
116#define reg v5
117#define stack v6
118
119.Ldumpstm: stm.w (instr, reg, stack, v7, lr), [sp-]
120 mov stack, r0
121 mov instr, r1
122 mov reg, #14
123 mov v7, #0
1241: mov r3, #1
125 csub.a reg, #8
126 bne 201f
127 sub reg, reg, #3
128201:
129 cand.a instr, r3 << reg
130 beq 2f
131 add v7, v7, #1
132 cxor.a v7, #6
133 cmoveq v7, #1
134 cmoveq r1, #'\n'
135 cmovne r1, #' '
136 ldw.w r3, [stack]+, #-4
137 mov r2, reg
138 csub.a r2, #8
139 bsl 201f
140 sub r2, r2, #3
141201:
142 cand.a instr, #0x40 @ if H is 1, high 16 regs
143 beq 201f
144 add r2, r2, #0x10 @ so r2 need add 16
145201:
146 adr r0, .Lfp
147 b.l printk
1482: sub.a reg, reg, #1
149 bns 1b
150 cxor.a v7, #0
151 beq 201f
152 adr r0, .Lcr
153 b.l printk
154201: ldm.w (instr, reg, stack, v7, pc), [sp]+
155
156.Lfp: .asciz "%cr%d:%08x"
157.Lcr: .asciz "\n"
158.Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n"
159 .align
160.Ldsi: .word 0x92eec000 >> 14 @ stm.w sp, (... fp, ip, lr, pc)
161 .word 0x92e10000 >> 14 @ stm.w sp, ()
162
163#endif
1/*
2 * linux/arch/unicore32/lib/backtrace.S
3 *
4 * Code specific to PKUnity SoC and UniCore ISA
5 *
6 * Copyright (C) 2001-2010 GUAN Xue-tao
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <linux/linkage.h>
13#include <asm/assembler.h>
14 .text
15
16@ fp is 0 or stack frame
17
18#define frame v4
19#define sv_fp v5
20#define sv_pc v6
21#define offset v8
22
23ENTRY(__backtrace)
24 mov r0, fp
25
26ENTRY(c_backtrace)
27
28#if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK)
29 mov pc, lr
30ENDPROC(__backtrace)
31ENDPROC(c_backtrace)
32#else
33 stm.w (v4 - v8, lr), [sp-] @ Save an extra register
34 @ so we have a location...
35 mov.a frame, r0 @ if frame pointer is zero
36 beq no_frame @ we have no stack frames
37
381: stm.w (pc), [sp-] @ calculate offset of PC stored
39 ldw.w r0, [sp]+, #4 @ by stmfd for this CPU
40 adr r1, 1b
41 sub offset, r0, r1
42
43/*
44 * Stack frame layout:
45 * optionally saved caller registers (r4 - r10)
46 * saved fp
47 * saved sp
48 * saved lr
49 * frame => saved pc
50 * optionally saved arguments (r0 - r3)
51 * saved sp => <next word>
52 *
53 * Functions start with the following code sequence:
54 * mov ip, sp
55 * stm.w (r0 - r3), [sp-] (optional)
56 * corrected pc => stm.w sp, (..., fp, ip, lr, pc)
57 */
58for_each_frame:
59
601001: ldw sv_pc, [frame+], #0 @ get saved pc
611002: ldw sv_fp, [frame+], #-12 @ get saved fp
62
63 sub sv_pc, sv_pc, offset @ Correct PC for prefetching
64
651003: ldw r2, [sv_pc+], #-4 @ if stmfd sp, {args} exists,
66 ldw r3, .Ldsi+4 @ adjust saved 'pc' back one
67 cxor.a r3, r2 >> #14 @ instruction
68 beq 201f
69 sub r0, sv_pc, #4 @ allow for mov
70 b 202f
71201:
72 sub r0, sv_pc, #8 @ allow for mov + stmia
73202:
74 ldw r1, [frame+], #-4 @ get saved lr
75 mov r2, frame
76 b.l dump_backtrace_entry
77
78 ldw r1, [sv_pc+], #-4 @ if stmfd sp, {args} exists,
79 ldw r3, .Ldsi+4
80 cxor.a r3, r1 >> #14
81 bne 1004f
82 ldw r0, [frame+], #-8 @ get sp
83 sub r0, r0, #4 @ point at the last arg
84 b.l .Ldumpstm @ dump saved registers
85
861004: ldw r1, [sv_pc+], #0 @ if stmfd {, fp, ip, lr, pc}
87 ldw r3, .Ldsi @ instruction exists,
88 cxor.a r3, r1 >> #14
89 bne 201f
90 sub r0, frame, #16
91 b.l .Ldumpstm @ dump saved registers
92201:
93 cxor.a sv_fp, #0 @ zero saved fp means
94 beq no_frame @ no further frames
95
96 csub.a sv_fp, frame @ next frame must be
97 mov frame, sv_fp @ above the current frame
98 bua for_each_frame
99
1001006: adr r0, .Lbad
101 mov r1, frame
102 b.l printk
103no_frame: ldm.w (v4 - v8, pc), [sp]+
104ENDPROC(__backtrace)
105ENDPROC(c_backtrace)
106
107 .pushsection __ex_table,"a"
108 .align 3
109 .long 1001b, 1006b
110 .long 1002b, 1006b
111 .long 1003b, 1006b
112 .long 1004b, 1006b
113 .popsection
114
115#define instr v4
116#define reg v5
117#define stack v6
118
119.Ldumpstm: stm.w (instr, reg, stack, v7, lr), [sp-]
120 mov stack, r0
121 mov instr, r1
122 mov reg, #14
123 mov v7, #0
1241: mov r3, #1
125 csub.a reg, #8
126 bne 201f
127 sub reg, reg, #3
128201:
129 cand.a instr, r3 << reg
130 beq 2f
131 add v7, v7, #1
132 cxor.a v7, #6
133 cmoveq v7, #1
134 cmoveq r1, #'\n'
135 cmovne r1, #' '
136 ldw.w r3, [stack]+, #-4
137 mov r2, reg
138 csub.a r2, #8
139 bsl 201f
140 sub r2, r2, #3
141201:
142 cand.a instr, #0x40 @ if H is 1, high 16 regs
143 beq 201f
144 add r2, r2, #0x10 @ so r2 need add 16
145201:
146 adr r0, .Lfp
147 b.l printk
1482: sub.a reg, reg, #1
149 bns 1b
150 cxor.a v7, #0
151 beq 201f
152 adr r0, .Lcr
153 b.l printk
154201: ldm.w (instr, reg, stack, v7, pc), [sp]+
155
156.Lfp: .asciz "%cr%d:%08x"
157.Lcr: .asciz "\n"
158.Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n"
159 .align
160.Ldsi: .word 0x92eec000 >> 14 @ stm.w sp, (... fp, ip, lr, pc)
161 .word 0x92e10000 >> 14 @ stm.w sp, ()
162
163#endif