1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * ARCv2 ISA based core Low Level Intr/Traps/E
4 *
5 * Copyright (C) 2013 Synopsys, Inc. (www.syno
6 */
7
8 #include <linux/linkage.h> /* ARC_{ENTRY,EXI
9 #include <asm/entry.h> /* SAVE_ALL_{INT1
10 #include <asm/errno.h>
11 #include <asm/arcregs.h>
12 #include <asm/irqflags.h>
13 #include <asm/mmu.h>
14
15 ; A maximum number of supported interrupts in
16 ; This number is not equal to the maximum inte
17 ; first 16 lines are reserved for exceptions a
18 #define NR_CPU_IRQS 240
19
20 .cpu HS
21
22 #define VECTOR .word
23
24 ;############################ Vector Table ###
25
26 .section .vector,"a",@progbits
27 .align 4
28
29 # Initial 16 slots are Exception Vectors
30 VECTOR res_service ; Reset Vector
31 VECTOR mem_service ; Mem exceptio
32 VECTOR instr_service ; Instrn Error
33 VECTOR EV_MachineCheck ; Fatal Machin
34 VECTOR EV_TLBMissI ; Instruction
35 VECTOR EV_TLBMissD ; Data TLB mis
36 VECTOR EV_TLBProtV ; Protection V
37 VECTOR EV_PrivilegeV ; Privilege Vi
38 VECTOR EV_SWI ; Software Bre
39 VECTOR EV_Trap ; Trap excepti
40 VECTOR EV_Extension ; Extn Instruc
41 VECTOR EV_DivZero ; Divide by Ze
42 VECTOR EV_DCError ; Data Cache E
43 VECTOR EV_Misaligned ; Misaligned D
44 VECTOR reserved ; Reserved slo
45 VECTOR reserved ; Reserved slo
46
47 # Begin Interrupt Vectors
48 VECTOR handle_interrupt ; (16) Timer0
49 VECTOR handle_interrupt ; unused (Time
50 VECTOR handle_interrupt ; unused (WDT)
51 VECTOR handle_interrupt ; (19) Inter c
52 VECTOR handle_interrupt ; (20) perf In
53 VECTOR handle_interrupt ; (21) Softwar
54 VECTOR handle_interrupt ; unused
55 VECTOR handle_interrupt ; (23) unused
56 # End of fixed IRQs
57
58 .rept NR_CPU_IRQS - 8
59 VECTOR handle_interrupt
60 .endr
61
62 .section .text, "ax",@progbits
63
64 reserved:
65 flag 1 ; Unexpected event, ha
66
67 ;##################### Interrupt Handling ####
68
69 ENTRY(handle_interrupt)
70
71 INTERRUPT_PROLOGUE
72
73 # irq control APIs local_irq_save/rest
74 # global interrupt enable bits in STAT
75 # However a taken interrupt doesn't cl
76 # query in hard ISR path would return
77 # trips genirq interrupt handling asse
78 #
79 # So do a "soft" disable of interrupts
80 #
81 # Note this disable is only for consis
82 # will be disabled anyways even w/o th
83 # separately in AUX_IRQ_ACT.active and
84 # unless this one returns (or higher p
85
86 IRQ_DISABLE
87
88 ; icause is banked: one per priority l
89 ; so a higher prio interrupt taken her
90 lr r0, [ICAUSE]
91 mov blink, ret_from_exception
92
93 b.d arch_do_IRQ
94 mov r1, sp
95
96 END(handle_interrupt)
97
98 ;################### Non TLB Exception Handlin
99
100 ENTRY(EV_SWI)
101 ; TODO: implement this
102 EXCEPTION_PROLOGUE
103 b ret_from_exception
104 END(EV_SWI)
105
106 ENTRY(EV_DivZero)
107 ; TODO: implement this
108 EXCEPTION_PROLOGUE
109 b ret_from_exception
110 END(EV_DivZero)
111
112 ENTRY(EV_DCError)
113 ; TODO: implement this
114 EXCEPTION_PROLOGUE
115 b ret_from_exception
116 END(EV_DCError)
117
118 ; --------------------------------------------
119 ; Memory Error Exception Handler
120 ; - Unlike ARCompact, handles Bus errors for
121 ; Instruction fetch or Data access, under
122 ; --------------------------------------------
123
124 ENTRY(mem_service)
125
126 EXCEPTION_PROLOGUE
127
128 bl do_memory_error
129 b ret_from_exception
130 END(mem_service)
131
132 ENTRY(EV_Misaligned)
133
134 EXCEPTION_PROLOGUE
135
136 SAVE_CALLEE_SAVED_USER
137 mov r2, sp ; callee_regs
138
139 bl do_misaligned_access
140
141 ; TBD: optimize - do this only if a ca
142 ; either a dst of emulated LD/ST or sr
143 RESTORE_CALLEE_SAVED_USER
144
145 b ret_from_exception
146 END(EV_Misaligned)
147
148 ; --------------------------------------------
149 ; Protection Violation Exception Handler
150 ; --------------------------------------------
151
152 ENTRY(EV_TLBProtV)
153
154 EXCEPTION_PROLOGUE
155
156 mov blink, ret_from_exception
157 b do_page_fault
158
159 END(EV_TLBProtV)
160
161 ; From Linux standpoint Slow Path I/D TLB Miss
162 ; need to call do_page_fault().
163 ; ECR in pt_regs provides whether access was R
164
165 .global call_do_page_fault
166 .set call_do_page_fault, EV_TLBProtV
167
168 ;############# Common Handlers for ARCompact a
169
170 #include "entry.S"
171
172 ;############# Return from Intr/Excp/Trap (ARC
173 ;
174 ; Restore the saved sys context (common exit-p
175 ; IRQ shd definitely not happen between now an
176 ; All 2 entry points to here already disable i
177
178 .Lrestore_regs:
179 restore_regs:
180
181 # Interrpts are actually disabled from
182 # reenabled after we return from inter
183 # But irq tracer needs to be told now.
184 TRACE_ASM_IRQ_ENABLE
185
186 ld r0, [sp, PT_status32] ; U/K
187 lr r10, [AUX_IRQ_ACT]
188
189 bmsk r11, r10, 15 ; extr
190 breq r11, 0, .Lexcept_ret ; No i
191
192 ;####### Return from Intr #######
193
194 .Lisr_ret:
195
196 debug_marker_l1:
197 ; bbit1.nt r0, STATUS_DE_BIT, .Lintr_r
198 btst r0, STATUS_DE_BIT
199 bnz .Lintr_ret_to_delay_slot
200
201 ; Handle special case #1: (Entry via E
202 ;
203 ; Exception in U mode, preempted in ke
204 ; task now returning to U mode (riding
205 ; AUX_IRQ_ACTIVE won't have U bit set
206 ; won't be switched to correct U mode
207 ; So force AUX_IRQ_ACT.U for such a ca
208
209 btst r0, STATUS_U_BIT
210 bset.nz r11, r11, AUX_IRQ_ACT_BIT_U
211 sr r11, [AUX_IRQ_ACT]
212
213 INTERRUPT_EPILOGUE
214 rtie
215
216 ;####### Return from Exception / pure kernel m
217
218 .Lexcept_ret: ; Expects r0 has PT_status32
219
220 debug_marker_syscall:
221 EXCEPTION_EPILOGUE
222 rtie
223
224 ;####### Return from Intr to insn in delay slo
225
226 ; Handle special case #2: (Entry via Exception
227 ;
228 ; Intr returning to a Delay Slot (DS) insn
229 ; (since IRQ NOT allowed in DS in ARCv2, this
230 ; entry was via Exception in DS which got pree
231 ;
232 ; IRQ RTIE won't reliably restore DE bit and/o
233 ;
234 ; Solution is to drop out of interrupt context
235 ; and return from pure kernel mode which does
236
237 .Lintr_ret_to_delay_slot:
238 debug_marker_ds:
239
240 ld r2, [@intr_to_DE_cnt]
241 add r2, r2, 1
242 st r2, [@intr_to_DE_cnt]
243
244 ; drop out of interrupt context (clear
245 bmskn r11, r10, 15
246 sr r11, [AUX_IRQ_ACT]
247 b .Lexcept_ret
248
249 END(ret_from_exception)
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.