| blob | 222742ddc0d6a656ae16b3e5eb9ae5ba0ddb3691 |
1 /*
2 * arch/sh/kernel/cpu/sh2a/entry.S
3 *
4 * The SH-2A exception entry
5 *
6 * Copyright (C) 2008 Yoshinori Sato
7 * Based on arch/sh/kernel/cpu/sh2/entry.S
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file "COPYING" in the main directory of this archive
11 * for more details.
12 */
14 #include <linux/linkage.h>
15 #include <asm/asm-offsets.h>
16 #include <asm/thread_info.h>
17 #include <cpu/mmu_context.h>
18 #include <asm/unistd.h>
19 #include <asm/errno.h>
20 #include <asm/page.h>
22 /* Offsets to the stack */
23 OFF_R0 = 0 /* Return value. New ABI also arg4 */
24 OFF_R1 = 4 /* New ABI: arg5 */
25 OFF_R2 = 8 /* New ABI: arg6 */
26 OFF_R3 = 12 /* New ABI: syscall_nr */
27 OFF_R4 = 16 /* New ABI: arg0 */
28 OFF_R5 = 20 /* New ABI: arg1 */
29 OFF_R6 = 24 /* New ABI: arg2 */
30 OFF_R7 = 28 /* New ABI: arg3 */
31 OFF_SP = (15*4)
32 OFF_PC = (16*4)
33 OFF_SR = (16*4+2*4)
34 OFF_TRA = (16*4+6*4)
36 #include <asm/entry-macros.S>
38 ENTRY(exception_handler)
39 ! stack
40 ! r0 <- point sp
41 ! r1
42 ! pc
43 ! sr
44 ! r0 = temporary
45 ! r1 = vector (pseudo EXPEVT / INTEVT / TRA)
46 mov.l r2,@-sp
47 cli
48 mov.l $cpu_mode,r2
49 bld.b #6,@(0,r2) !previus SR.MD
50 bst.b #6,@(4*4,r15) !set cpu mode to SR.MD
51 bt 1f
52 ! switch to kernel mode
53 bset.b #6,@(0,r2) !set SR.MD
54 mov.l $current_thread_info,r2
55 mov.l @r2,r2
56 mov #(THREAD_SIZE >> 8),r0
57 shll8 r0
58 add r2,r0 ! r0 = kernel stack tail
59 mov r15,r2 ! r2 = user stack top
60 mov r0,r15 ! switch kernel stack
61 mov.l r1,@-r15 ! TRA
62 sts.l macl, @-r15
63 sts.l mach, @-r15
64 stc.l gbr, @-r15
65 mov.l @(4*4,r2),r0
66 mov.l r0,@-r15 ! original SR
67 sts.l pr,@-r15
68 mov.l @(3*4,r2),r0
69 mov.l r0,@-r15 ! original PC
70 mov r2,r0
71 add #(3+2)*4,r0 ! rewind r0 - r3 + exception frame
72 lds r0,pr ! pr = original SP
73 movmu.l r3,@-r15 ! save regs
74 mov r2,r8 ! r8 = previus stack top
75 mov r1,r9 ! r9 = interrupt vector
76 ! restore previous stack
77 mov.l @r8+,r2
78 mov.l @r8+,r0
79 mov.l @r8+,r1
80 bra 2f
81 movml.l r2,@-r15
82 1:
83 ! in kernel exception
84 mov r15,r2
85 add #-((OFF_TRA + 4) - OFF_PC) + 5*4,r15
86 movmu.l r3,@-r15
87 mov r2,r8 ! r8 = previous stack top
88 mov r1,r9 ! r9 = interrupt vector
89 ! restore exception frame & regs
90 mov.l @r8+,r2 ! old R2
91 mov.l @r8+,r0 ! old R0
92 mov.l @r8+,r1 ! old R1
93 mov.l @r8+,r10 ! old PC
94 mov.l @r8+,r11 ! old SR
95 movml.l r2,@-r15
96 mov.l r10,@(OFF_PC,r15)
97 mov.l r11,@(OFF_SR,r15)
98 mov.l r8,@(OFF_SP,r15) ! save old sp
99 mov r15,r8
100 add #OFF_TRA + 4,r8
101 mov.l r9,@-r8
102 sts.l macl,@-r8
103 sts.l mach,@-r8
104 stc.l gbr,@-r8
105 add #-4,r8
106 sts.l pr,@-r8
107 2:
108 ! dispatch exception / interrupt
109 mov #64,r8
110 cmp/hs r8,r9
111 bt interrupt_entry ! vec >= 64 is interrupt
112 mov #32,r8
113 cmp/hs r8,r9
114 bt trap_entry ! 64 > vec >= 32 is trap
116 mov.l 4f,r8
117 mov r9,r4
118 shll2 r9
119 add r9,r8
120 mov.l @r8,r8 ! exception handler address
121 tst r8,r8
122 bf 3f
123 mov.l 8f,r8 ! unhandled exception
124 3:
125 mov.l 5f,r10
126 jmp @r8
127 lds r10,pr
129 interrupt_entry:
130 mov r9,r4
131 mov r15,r5
132 mov.l 7f,r8
133 mov.l 6f,r9
134 jmp @r8
135 lds r9,pr
137 .align 2
138 4: .long exception_handling_table
139 5: .long ret_from_exception
140 6: .long ret_from_irq
141 7: .long do_IRQ
142 8: .long exception_error
144 trap_entry:
145 mov #0x30,r8
146 cmp/ge r8,r9 ! vector 0x20-0x2f is systemcall
147 bt 1f
148 add #-0x10,r9 ! convert SH2 to SH3/4 ABI
149 1:
150 shll2 r9 ! TRA
151 bra system_call ! jump common systemcall entry
152 mov r9,r8
154 #if defined(CONFIG_SH_STANDARD_BIOS)
155 /* Unwind the stack and jmp to the debug entry */
156 ENTRY(sh_bios_handler)
157 mov r15,r0
158 add #(22-4)*4-4,r0
159 ldc.l @r0+,gbr
160 lds.l @r0+,mach
161 lds.l @r0+,macl
162 mov r15,r0
163 mov.l @(OFF_SP,r0),r1
164 mov.l @(OFF_SR,r2),r3
165 mov.l r3,@-r1
166 mov.l @(OFF_SP,r2),r3
167 mov.l r3,@-r1
168 mov r15,r0
169 add #(22-4)*4-8,r0
170 mov.l 1f,r2
171 mov.l @r2,r2
172 stc sr,r3
173 mov.l r2,@r0
174 mov.l r3,@(4,r0)
175 mov.l r1,@(8,r0)
176 movml.l @r15+,r14
177 add #8,r15
178 lds.l @r15+, pr
179 mov.l @r15+,r15
180 rte
181 nop
182 .align 2
183 1: .long gdb_vbr_vector
184 #endif /* CONFIG_SH_STANDARD_BIOS */
186 ENTRY(address_error_trap_handler)
187 mov r15,r4 ! regs
188 mov.l @(OFF_PC,r15),r6 ! pc
189 mov.l 1f,r0
190 jmp @r0
191 mov #0,r5 ! writeaccess is unknown
193 .align 2
194 1: .long do_address_error
196 restore_all:
197 stc sr,r0
198 or #0xf0,r0
199 ldc r0,sr ! all interrupt block (same BL = 1)
200 ! restore special register
201 ! overlap exception frame
202 mov r15,r0
203 add #17*4,r0
204 lds.l @r0+,pr
205 add #4,r0
206 ldc.l @r0+,gbr
207 lds.l @r0+,mach
208 lds.l @r0+,macl
209 mov r15,r0
210 mov.l $cpu_mode,r2
211 bld.b #6,@(OFF_SR,r15)
212 bst.b #6,@(0,r2) ! save CPU mode
213 mov.l @(OFF_SR,r0),r1
214 shll2 r1
215 shlr2 r1 ! clear MD bit
216 mov.l @(OFF_SP,r0),r2
217 add #-8,r2
218 mov.l r2,@(OFF_SP,r0) ! point exception frame top
219 mov.l r1,@(4,r2) ! set sr
220 mov.l @(OFF_PC,r0),r1
221 mov.l r1,@r2 ! set pc
222 get_current_thread_info r0, r1
223 mov.l $current_thread_info,r1
224 mov.l r0,@r1
225 movml.l @r15+,r14
226 mov.l @r15,r15
227 rte
228 nop
230 .align 2
231 $current_thread_info:
232 .long __current_thread_info
233 $cpu_mode:
234 .long __cpu_mode
236 ! common exception handler
237 #include "../../entry-common.S"
239 .data
240 ! cpu operation mode
241 ! bit30 = MD (compatible SH3/4)
242 __cpu_mode:
243 .long 0x40000000
245 .section .bss
246 __current_thread_info:
247 .long 0
249 ENTRY(exception_handling_table)
250 .space 4*32