1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_ARC_ENTRY_ARCV2_H
#define __ASM_ARC_ENTRY_ARCV2_H
#include <asm/asm-offsets.h>
#include <asm/dsp-impl.h>
#include <asm/irqflags-arcv2.h>
#include <asm/thread_info.h> /* For THREAD_SIZE */
/*
* Interrupt/Exception stack layout (pt_regs) for ARCv2
* (End of struct aligned to end of page [unless nested])
*
* INTERRUPT EXCEPTION
*
* manual --------------------- manual
* | orig_r0 |
* | event/ECR |
* | bta |
* | user_r25 |
* | gp |
* | fp |
* | sp |
* | r12 |
* | r30 |
* | r58 |
* | r59 |
* hw autosave ---------------------
* optional | r0 |
* | r1 |
* ~ ~
* | r9 |
* | r10 |
* | r11 |
* | blink |
* | lpe |
* | lps |
* | lpc |
* | ei base |
* | ldi base |
* | jli base |
* ---------------------
* hw autosave | pc / eret |
* mandatory | stat32 / erstatus |
* ---------------------
*/
/*------------------------------------------------------------------------*/
.macro INTERRUPT_PROLOGUE
; (A) Before jumping to Interrupt Vector, hardware micro-ops did following:
; 1. SP auto-switched to kernel mode stack
; 2. STATUS32.Z flag set if in U mode at time of interrupt (U:1,K:0)
; 3. Auto save: (mandatory) Push PC and STAT32 on stack
; hardware does even if CONFIG_ARC_IRQ_NO_AUTOSAVE
; 4. Auto save: (optional) r0-r11, blink, LPE,LPS,LPC, JLI,LDI,EI
;
; (B) Manually saved some regs: r12,r25,r30, sp,fp,gp, ACCL pair
#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE
; carve pt_regs on stack (case #3), PC/STAT32 already on stack
sub sp, sp, SZ_PT_REGS - 8
__SAVE_REGFILE_HARD
#else
; carve pt_regs on stack (case #4), which grew partially already
sub sp, sp, PT_r0
#endif
__SAVE_REGFILE_SOFT
.endm
/*------------------------------------------------------------------------*/
.macro EXCEPTION_PROLOGUE
; (A) Before jumping to Exception Vector, hardware micro-ops did following:
; 1. SP auto-switched to kernel mode stack
; 2. STATUS32.Z flag set if in U mode at time of exception (U:1,K:0)
;
; (B) Manually save the complete reg file below
sub sp, sp, SZ_PT_REGS ; carve pt_regs
; _HARD saves r10 clobbered by _SOFT as scratch hence comes first
__SAVE_REGFILE_HARD
__SAVE_REGFILE_SOFT
st r0, [sp] ; orig_r0
lr r10, [eret]
lr r11, [erstatus]
ST2 r10, r11, PT_ret
lr r10, [ecr]
lr r11, [erbta]
ST2 r10, r11, PT_event
; OUTPUT: r10 has ECR expected by EV_Trap
.endm
/*------------------------------------------------------------------------
* This macro saves the registers manually which would normally be autosaved
* by hardware on taken interrupts. It is used by
* - exception handlers (which don't have autosave)
* - interrupt autosave disabled due to CONFIG_ARC_IRQ_NO_AUTOSAVE
*/
.macro __SAVE_REGFILE_HARD
ST2 r0, r1, PT_r0
ST2 r2, r3, PT_r2
ST2 r4, r5, PT_r4
ST2 r6, r7, PT_r6
ST2 r8, r9, PT_r8
ST2 r10, r11, PT_r10
st blink, [sp, PT_blink]
lr r10, [lp_end]
lr r11, [lp_start]
ST2 r10, r11, PT_lpe
st lp_count, [sp, PT_lpc]
; skip JLI, LDI, EI for now
.endm
/*------------------------------------------------------------------------
* This macros saves a bunch of other registers which can't be autosaved for
* various reasons:
* - r12: the last caller saved scratch reg since hardware saves in pairs so r0-r11
* - r30: free reg, used by gcc as scratch
* - ACCL/ACCH pair when they exist
*/
.macro __SAVE_REGFILE_SOFT
ST2 gp, fp, PT_r26 ; gp (r26), fp (r27)
st r12, [sp, PT_sp + 4]
st r30, [sp, PT_sp + 8]
; Saving pt_regs->sp correctly requires some extra work due to the way
; Auto stack switch works
; - U mode: retrieve it from AUX_USER_SP
; - K mode: add the offset from current SP where H/w starts auto push
;
; 1. Utilize the fact that Z bit is set if Intr taken in U mode
; 2. Upon entry SP is always saved (for any inspection, unwinding etc),
; but on return, restored only if U mode
lr r10, [AUX_USER_SP] ; U mode SP
; ISA requires ADD.nz to have same dest and src reg operands
mov.nz r10, sp
add.nz r10, r10, SZ_PT_REGS ; K mode SP
st r10, [sp, PT_sp] ; SP (pt_regs->sp)
#ifdef CONFIG_ARC_CURR_IN_REG
st r25, [sp, PT_user_r25]
GET_CURR_TASK_ON_CPU r25
#endif
#ifdef CONFIG_ARC_HAS_ACCL_REGS
ST2 r58, r59, PT_r58
#endif
/* clobbers r10, r11 registers pair */
DSP_SAVE_REGFILE_IRQ
.endm
/*------------------------------------------------------------------------*/
.macro __RESTORE_REGFILE_SOFT
LD2 gp, fp, PT_r26 ; gp (r26), fp (r27)
ld r12, [sp, PT_r12]
ld r30, [sp, PT_r30]
; Restore SP (into AUX_USER_SP) only if returning to U mode
; - for K mode, it will be implicitly restored as stack is unwound
; - Z flag set on K is inverse of what hardware does on interrupt entry
; but that doesn't really matter
bz 1f
ld r10, [sp, PT_sp] ; SP (pt_regs->sp)
sr r10, [AUX_USER_SP]
1:
#ifdef CONFIG_ARC_CURR_IN_REG
ld r25, [sp, PT_user_r25]
#endif
/* clobbers r10, r11 registers pair */
DSP_RESTORE_REGFILE_IRQ
#ifdef CONFIG_ARC_HAS_ACCL_REGS
LD2 r58, r59, PT_r58
#endif
.endm
/*------------------------------------------------------------------------*/
.macro __RESTORE_REGFILE_HARD
ld blink, [sp, PT_blink]
LD2 r10, r11, PT_lpe
sr r10, [lp_end]
sr r11, [lp_start]
ld r10, [sp, PT_lpc] ; lp_count can't be target of LD
mov lp_count, r10
LD2 r0, r1, PT_r0
LD2 r2, r3, PT_r2
LD2 r4, r5, PT_r4
LD2 r6, r7, PT_r6
LD2 r8, r9, PT_r8
LD2 r10, r11, PT_r10
.endm
/*------------------------------------------------------------------------*/
.macro INTERRUPT_EPILOGUE
; INPUT: r0 has STAT32 of calling context
; INPUT: Z flag set if returning to K mode
; _SOFT clobbers r10 restored by _HARD hence the order
__RESTORE_REGFILE_SOFT
#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE
__RESTORE_REGFILE_HARD
add sp, sp, SZ_PT_REGS - 8
#else
add sp, sp, PT_r0
#endif
.endm
/*------------------------------------------------------------------------*/
.macro EXCEPTION_EPILOGUE
; INPUT: r0 has STAT32 of calling context
btst r0, STATUS_U_BIT ; Z flag set if K, used in restoring SP
ld r10, [sp, PT_event + 4]
sr r10, [erbta]
LD2 r10, r11, PT_ret
sr r10, [eret]
sr r11, [erstatus]
__RESTORE_REGFILE_SOFT
__RESTORE_REGFILE_HARD
add sp, sp, SZ_PT_REGS
.endm
.macro FAKE_RET_FROM_EXCPN
lr r9, [status32]
bic r9, r9, STATUS_AE_MASK
or r9, r9, STATUS_IE_MASK
kflag r9
.endm
/* Get thread_info of "current" tsk */
.macro GET_CURR_THR_INFO_FROM_SP reg
bmskn \reg, sp, THREAD_SHIFT - 1
.endm
/* Get CPU-ID of this core */
.macro GET_CPU_ID reg
lr \reg, [identity]
xbfu \reg, \reg, 0xE8 /* 00111 01000 */
/* M = 8-1 N = 8 */
.endm
#endif
|
