1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Low Level Interrupts/Traps/Exceptions(non-T
4 *
5 * Copyright (C) 2014-15 Synopsys, Inc. (www.s
6 * Copyright (C) 2004, 2007-2010, 2011-2012 Sy
7 *
8 * vineetg: May 2011
9 * -Userspace unaligned access emulation
10 *
11 * vineetg: Feb 2011 (ptrace low level code fi
12 * -traced syscall return code (r0) was not s
13 * into user reg-file when traded task rets
14 * -syscalls needing arch-wrappers (mainly fo
15 * were not invoking post-syscall trace hook
16 * ret_from_system_call)
17 *
18 * vineetg: Nov 2010:
19 * -Vector table jumps (@8 bytes) converted i
20 * -To maintain the slot size of 8 bytes/vect
21 * not executed at runtime.
22 *
23 * vineetg: Nov 2009 (Everything needed for TI
24 * -do_signal()invoked upon TIF_RESTORE_SIGMA
25 * -Wrappers for sys_{,rt_}sigsuspend() no lo
26 * need ptregs anymore
27 *
28 * Vineetg: Oct 2009
29 * -In a rare scenario, Process gets a Priv-V
30 * out. Since we don't do FAKE RTIE for Priv
31 * active (AE bit enabled). This causes a d
32 * exception. Thus FAKE RTIE needed in low l
33 * Instr Error could also cause similar scen
34 *
35 * Vineetg: March 2009 (Supporting 2 levels of
36 *
37 * Vineetg: Aug 28th 2008: Bug #94984
38 * -Zero Overhead Loop Context shd be cleared
39 * Normally CPU does this automatically, how
40 * we need to explicitly do this. The proble
41 * FAKE_RET_FROM_EXCPN and FAKE_RET_FROM_EXC
42 * was being "CLEARED" rather then "SET". Si
43 * setting it and not clearing it clears ZOL
44 *
45 * Vineetg: May 16th, 2008
46 * - r25 now contains the Current Task when i
47 *
48 * Vineetg: Dec 22, 2007
49 * Minor Surgery of Low Level ISR to make i
50 * - MMU_SCRATCH0 Reg used for freeing up r
51 * - _current_task is made an array of NR_C
52 * - Access of _current_task wrapped inside
53 * team agrees for a dedicated reg, no o
54 *
55 * Amit Bhor, Rahul Trivedi, Kanika Nema, Same
56 */
57
58 #include <linux/errno.h>
59 #include <linux/linkage.h> /* {ENTRY,EXIT
60 #include <asm/entry.h>
61 #include <asm/irqflags.h>
62
63 .cpu A7
64
65 ;############################ Vector Table ###
66
67 .macro VECTOR lbl
68 #if 1 /* Just in case, build breaks */
69 j \lbl
70 #else
71 b \lbl
72 nop
73 #endif
74 .endm
75
76 .section .vector, "ax",@progbits
77 .align 4
78
79 /* Each entry in the vector table must occupy
80 * across sections (.vector to .text) we are g
81 * will use the 'j limm' form of the instructi
82 * a section other than .vector.
83 */
84
85 ; ********* Critical System Events ***********
86 VECTOR res_service ; 0x0, Reset
87 VECTOR mem_service ; 0x8, Mem ex
88 VECTOR instr_service ; 0x10, Instr
89
90 ; ******************** Device ISRs ***********
91 #ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
92 VECTOR handle_interrupt_level2
93 #else
94 VECTOR handle_interrupt_level1
95 #endif
96
97 .rept 28
98 VECTOR handle_interrupt_level1 ; Other devic
99 .endr
100
101 /* FOR ARC600: timer = 0x3, uart = 0x8, emac =
102
103 ; ******************** Exceptions ************
104 VECTOR EV_MachineCheck ; 0x100, Fata
105 VECTOR EV_TLBMissI ; 0x108, Inst
106 VECTOR EV_TLBMissD ; 0x110, Data
107 VECTOR EV_TLBProtV ; 0x118, Prot
108 ; or
109 VECTOR EV_PrivilegeV ; 0x120, Priv
110 VECTOR EV_Trap ; 0x128, Trap
111 VECTOR EV_Extension ; 0x130, Extn
112
113 .rept 24
114 VECTOR reserved ; Reserved Ex
115 .endr
116
117
118 ;##################### Scratch Mem for IRQ sta
119
120 ARCFP_DATA int1_saved_reg
121 .align 32
122 .type int1_saved_reg, @object
123 .size int1_saved_reg, 4
124 int1_saved_reg:
125 .zero 4
126
127 /* Each Interrupt level needs its own scratch
128 ARCFP_DATA int2_saved_reg
129 .type int2_saved_reg, @object
130 .size int2_saved_reg, 4
131 int2_saved_reg:
132 .zero 4
133
134 ; --------------------------------------------
135 .section .text, "ax",@progbits
136
137
138 reserved:
139 flag 1 ; Unexpected event, ha
140
141 ;##################### Interrupt Handling ####
142
143 #ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
144 ; --------------------------------------------
145 ; Level 2 ISR: Can interrupt a Level 1 ISR
146 ; --------------------------------------------
147 ENTRY(handle_interrupt_level2)
148
149 INTERRUPT_PROLOGUE 2
150
151 ;-------------------------------------
152 ; if L2 IRQ interrupted a L1 ISR, disa
153 ;
154 ; This is to avoid a potential L1-L2-L
155 ; -L1 IRQ taken
156 ; -L2 interrupts L1 (before L1 ISR co
157 ; -preemption off IRQ, user task in s
158 ; -RTIE to userspace
159 ; Returns from L2 context fine
160 ; But both L1 and L2 re-enabled,
161 ; while prev L1 is still unservi
162 ;
163 ;-------------------------------------
164
165 ; L2 interrupting L1 implies both L2 a
166 ; However both A2 and A1 are NOT set i
167 ; need to check STATUS32_L2 to determi
168
169 ld r9, [sp, PT_status32] ; get
170 bbit0 r9, STATUS_A1_BIT, 1f ; L1 n
171
172 ; bump thread_info->preempt_count (Dis
173 GET_CURR_THR_INFO_FROM_SP r10
174 ld r9, [r10, THREAD_INFO_PREEMPT_
175 add r9, r9, 1
176 st r9, [r10, THREAD_INFO_PREEMPT_
177
178 1:
179 ;-------------------------------------
180 ; setup params for Linux common ISR an
181 ;-------------------------------------
182 lr r0, [icause2]
183 and r0, r0, 0x1f
184
185 bl.d @arch_do_IRQ
186 mov r1, sp
187
188 mov r8,0x2
189 sr r8, [AUX_IRQ_LV12] ; clear bi
190
191 b ret_from_exception
192
193 END(handle_interrupt_level2)
194
195 #endif
196
197 ; --------------------------------------------
198 ; User Mode Memory Bus Error Interrupt Handler
199 ; (Kernel mode memory errors handled via separ
200 ; --------------------------------------------
201 ENTRY(mem_service)
202
203 INTERRUPT_PROLOGUE 2
204
205 mov r0, ilink2
206 mov r1, sp
207
208 ; User process needs to be killed with
209 ; out of the L2 interrupt context (dro
210 ; off to "C" code where SIGBUS in enqu
211 lr r3, [status32]
212 bclr r3, r3, STATUS_A2_BIT
213 or r3, r3, (STATUS_E1_MASK|STATUS_E2_
214 sr r3, [status32_l2]
215 mov ilink2, 1f
216 rtie
217 1:
218 bl do_memory_error
219 b ret_from_exception
220 END(mem_service)
221
222 ; --------------------------------------------
223 ; Level 1 ISR
224 ; --------------------------------------------
225 ENTRY(handle_interrupt_level1)
226
227 INTERRUPT_PROLOGUE 1
228
229 lr r0, [icause1]
230 and r0, r0, 0x1f
231
232 #ifdef CONFIG_TRACE_IRQFLAGS
233 ; icause1 needs to be read early, befo
234 ; can clobber scratch regs, hence use
235 push r0
236 TRACE_ASM_IRQ_DISABLE
237 pop r0
238 #endif
239
240 bl.d @arch_do_IRQ
241 mov r1, sp
242
243 mov r8,0x1
244 sr r8, [AUX_IRQ_LV12] ; clear bi
245
246 b ret_from_exception
247 END(handle_interrupt_level1)
248
249 ;################### Non TLB Exception Handlin
250
251 ; --------------------------------------------
252 ; Protection Violation Exception Handler
253 ; --------------------------------------------
254
255 ENTRY(EV_TLBProtV)
256
257 EXCEPTION_PROLOGUE ; ECR returned
258
259 ;------ (5) Type of Protection Violati
260 ;
261 ; ProtV Hardware Exception is triggere
262 ; -Access Violation : 00_23_(00|01
263 ; x r
264 ; -Unaligned Access : 00_23_04_00
265 bbit1 r10, ECR_C_BIT_PROTV_MISALIG_DAT
266
267 ;========= (6a) Access Violation Proce
268 bl do_page_fault
269 b ret_from_exception
270
271 ;========== (6b) Non aligned access ==
272 4:
273
274 SAVE_CALLEE_SAVED_USER
275 mov r2, sp ; callee_regs
276
277 bl do_misaligned_access
278
279 ; TBD: optimize - do this only if a ca
280 ; either a dst of emulated LD/ST or sr
281 RESTORE_CALLEE_SAVED_USER
282
283 b ret_from_exception
284
285 END(EV_TLBProtV)
286
287 ; Wrapper for Linux page fault handler called
288 ; Very similar to ProtV handler case (6a) abov
289 ; for Misaligned access
290 ;
291 ENTRY(call_do_page_fault)
292
293 EXCEPTION_PROLOGUE
294
295 mov blink, ret_from_exception
296 b do_page_fault
297
298 END(call_do_page_fault)
299
300 ;############# Common Handlers for ARCompact a
301
302 #include "entry.S"
303
304 ;############# Return from Intr/Excp/Trap (ARC
305 ;
306 ; Restore the saved sys context (common exit-p
307 ; IRQ shd definitely not happen between now an
308 ; All 2 entry points to here already disable i
309
310 .Lrestore_regs:
311
312 # Interrupts are actually disabled fro
313 # reenabled after we return from inter
314 # But irq tracer needs to be told now.
315 TRACE_ASM_IRQ_ENABLE
316
317 lr r10, [status32]
318
319 ; Restore REG File. In case multiple E
320 ; use the same priority as rtie: EXCPN
321 ; Note that we use realtime STATUS32 (
322 ; decide that.
323
324 and.f 0, r10, (STATUS_A1_MASK|STATUS
325 bz .Lexcep_or_pure_K_ret
326
327 ; Returning from Interrupts (Level 1 o
328
329 #ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
330
331 ; Level 2 interrupt return Path - from
332 bbit0 r10, STATUS_A2_BIT, not_level2_
333
334 ;-------------------------------------
335 ; However the context returning might
336 ; e.g. Task'A' user-code -> L2 intr ->
337 ; Special considerations needed for th
338
339 ld r9, [sp, PT_event] ; Ensur
340 brne r9, event_IRQ2, 149f
341
342 ;-------------------------------------
343 ; if L2 IRQ interrupted an L1 ISR, we
344 ; so that sched doesn't move to new ta
345 ; undeterministically. Now that we've
346 ; things to what they were, before ret
347 ;-------------------------------------
348
349 ld r9, [sp, PT_status32] ; get s
350 bbit0 r9, STATUS_A1_BIT, 149f ; L1 no
351
352 ; decrement thread_info->preempt_count
353 GET_CURR_THR_INFO_FROM_SP r10
354 ld r9, [r10, THREAD_INFO_PREEMPT_
355
356 ; paranoid check, given A1 was active
357 ; must not be 0 because we would have
358 ; If this does happen we simply HALT a
359 cmp r9, 0
360 bnz 2f
361 flag 1
362
363 2:
364 sub r9, r9, 1
365 st r9, [r10, THREAD_INFO_PREEMPT_
366
367 149:
368 INTERRUPT_EPILOGUE 2 ; return from
369 debug_marker_l2:
370 rtie
371
372 not_level2_interrupt:
373
374 #endif
375
376 INTERRUPT_EPILOGUE 1 ; return from
377 debug_marker_l1:
378 rtie
379
380 .Lexcep_or_pure_K_ret:
381
382 ;this case is for syscalls or Exceptio
383
384 EXCEPTION_EPILOGUE
385 debug_marker_syscall:
386 rtie
387
388 END(ret_from_exception)
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