xref: /linux/arch/arc/include/asm/entry.h (revision 1918693ff1891ba57af22dbbf511cf300158a975)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
4  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
5  */
6 
7 #ifndef __ASM_ARC_ENTRY_H
8 #define __ASM_ARC_ENTRY_H
9 
10 #include <asm/unistd.h>		/* For NR_syscalls defination */
11 #include <asm/arcregs.h>
12 #include <asm/ptrace.h>
13 #include <asm/processor.h>	/* For VMALLOC_START */
14 #include <asm/mmu.h>
15 
16 #ifdef __ASSEMBLY__
17 
18 #ifdef CONFIG_ISA_ARCOMPACT
19 #include <asm/entry-compact.h>	/* ISA specific bits */
20 #else
21 #include <asm/entry-arcv2.h>
22 #endif
23 
24 /* Note on the LD/ST addr modes with addr reg wback
25  *
26  * LD.a same as LD.aw
27  *
28  * LD.a    reg1, [reg2, x]  => Pre Incr
29  *      Eff Addr for load = [reg2 + x]
30  *
31  * LD.ab   reg1, [reg2, x]  => Post Incr
32  *      Eff Addr for load = [reg2]
33  */
34 
35 .macro PUSH reg
36 	st.a	\reg, [sp, -4]
37 .endm
38 
39 .macro PUSHAX aux
40 	lr	r9, [\aux]
41 	PUSH	r9
42 .endm
43 
44 .macro POP reg
45 	ld.ab	\reg, [sp, 4]
46 .endm
47 
48 .macro POPAX aux
49 	POP	r9
50 	sr	r9, [\aux]
51 .endm
52 
53 /*--------------------------------------------------------------
54  * Helpers to save/restore Scratch Regs:
55  * used by Interrupt/Exception Prologue/Epilogue
56  *-------------------------------------------------------------*/
57 .macro  SAVE_R0_TO_R12
58 	PUSH	r0
59 	PUSH	r1
60 	PUSH	r2
61 	PUSH	r3
62 	PUSH	r4
63 	PUSH	r5
64 	PUSH	r6
65 	PUSH	r7
66 	PUSH	r8
67 	PUSH	r9
68 	PUSH	r10
69 	PUSH	r11
70 	PUSH	r12
71 .endm
72 
73 .macro RESTORE_R12_TO_R0
74 	POP	r12
75 	POP	r11
76 	POP	r10
77 	POP	r9
78 	POP	r8
79 	POP	r7
80 	POP	r6
81 	POP	r5
82 	POP	r4
83 	POP	r3
84 	POP	r2
85 	POP	r1
86 	POP	r0
87 
88 .endm
89 
90 /*--------------------------------------------------------------
91  * Helpers to save/restore callee-saved regs:
92  * used by several macros below
93  *-------------------------------------------------------------*/
94 .macro SAVE_R13_TO_R24
95 	PUSH	r13
96 	PUSH	r14
97 	PUSH	r15
98 	PUSH	r16
99 	PUSH	r17
100 	PUSH	r18
101 	PUSH	r19
102 	PUSH	r20
103 	PUSH	r21
104 	PUSH	r22
105 	PUSH	r23
106 	PUSH	r24
107 .endm
108 
109 .macro RESTORE_R24_TO_R13
110 	POP	r24
111 	POP	r23
112 	POP	r22
113 	POP	r21
114 	POP	r20
115 	POP	r19
116 	POP	r18
117 	POP	r17
118 	POP	r16
119 	POP	r15
120 	POP	r14
121 	POP	r13
122 .endm
123 
124 /*--------------------------------------------------------------
125  * Collect User Mode callee regs as struct callee_regs - needed by
126  * fork/do_signal/unaligned-access-emulation.
127  * (By default only scratch regs are saved on entry to kernel)
128  *
129  * Special handling for r25 if used for caching Task Pointer.
130  * It would have been saved in task->thread.user_r25 already, but to keep
131  * the interface same it is copied into regular r25 placeholder in
132  * struct callee_regs.
133  *-------------------------------------------------------------*/
134 .macro SAVE_CALLEE_SAVED_USER
135 
136 	mov	r12, sp		; save SP as ref to pt_regs
137 	SAVE_R13_TO_R24
138 
139 #ifdef CONFIG_ARC_CURR_IN_REG
140 	; Retrieve orig r25 and save it with rest of callee_regs
141 	ld	r12, [r12, PT_user_r25]
142 	PUSH	r12
143 #else
144 	PUSH	r25
145 #endif
146 
147 .endm
148 
149 /*--------------------------------------------------------------
150  * Save kernel Mode callee regs at the time of Contect Switch.
151  *
152  * Special handling for r25 if used for caching Task Pointer.
153  * Kernel simply skips saving it since it will be loaded with
154  * incoming task pointer anyways
155  *-------------------------------------------------------------*/
156 .macro SAVE_CALLEE_SAVED_KERNEL
157 
158 	SAVE_R13_TO_R24
159 
160 #ifdef CONFIG_ARC_CURR_IN_REG
161 	sub     sp, sp, 4
162 #else
163 	PUSH	r25
164 #endif
165 .endm
166 
167 /*--------------------------------------------------------------
168  * Opposite of SAVE_CALLEE_SAVED_KERNEL
169  *-------------------------------------------------------------*/
170 .macro RESTORE_CALLEE_SAVED_KERNEL
171 
172 #ifdef CONFIG_ARC_CURR_IN_REG
173 	add     sp, sp, 4  /* skip usual r25 placeholder */
174 #else
175 	POP	r25
176 #endif
177 	RESTORE_R24_TO_R13
178 .endm
179 
180 /*--------------------------------------------------------------
181  * Opposite of SAVE_CALLEE_SAVED_USER
182  *
183  * ptrace tracer or unaligned-access fixup might have changed a user mode
184  * callee reg which is saved back to usual r25 storage location
185  *-------------------------------------------------------------*/
186 .macro RESTORE_CALLEE_SAVED_USER
187 
188 #ifdef CONFIG_ARC_CURR_IN_REG
189 	POP	r12
190 #else
191 	POP	r25
192 #endif
193 	RESTORE_R24_TO_R13
194 
195 	; SP is back to start of pt_regs
196 #ifdef CONFIG_ARC_CURR_IN_REG
197 	st	r12, [sp, PT_user_r25]
198 #endif
199 .endm
200 
201 /*--------------------------------------------------------------
202  * Super FAST Restore callee saved regs by simply re-adjusting SP
203  *-------------------------------------------------------------*/
204 .macro DISCARD_CALLEE_SAVED_USER
205 	add     sp, sp, SZ_CALLEE_REGS
206 .endm
207 
208 /*-------------------------------------------------------------
209  * given a tsk struct, get to the base of it's kernel mode stack
210  * tsk->thread_info is really a PAGE, whose bottom hoists stack
211  * which grows upwards towards thread_info
212  *------------------------------------------------------------*/
213 
214 .macro GET_TSK_STACK_BASE tsk, out
215 
216 	/* Get task->thread_info (this is essentially start of a PAGE) */
217 	ld  \out, [\tsk, TASK_THREAD_INFO]
218 
219 	/* Go to end of page where stack begins (grows upwards) */
220 	add2 \out, \out, (THREAD_SIZE)/4
221 
222 .endm
223 
224 /*
225  * @reg [OUT] thread_info->flags of "current"
226  */
227 .macro GET_CURR_THR_INFO_FLAGS  reg
228 	GET_CURR_THR_INFO_FROM_SP  \reg
229 	ld  \reg, [\reg, THREAD_INFO_FLAGS]
230 .endm
231 
232 #ifdef CONFIG_SMP
233 
234 /*-------------------------------------------------
235  * Retrieve the current running task on this CPU
236  * 1. Determine curr CPU id.
237  * 2. Use it to index into _current_task[ ]
238  */
239 .macro  GET_CURR_TASK_ON_CPU   reg
240 	GET_CPU_ID  \reg
241 	ld.as  \reg, [@_current_task, \reg]
242 .endm
243 
244 /*-------------------------------------------------
245  * Save a new task as the "current" task on this CPU
246  * 1. Determine curr CPU id.
247  * 2. Use it to index into _current_task[ ]
248  *
249  * Coded differently than GET_CURR_TASK_ON_CPU (which uses LD.AS)
250  * because ST r0, [r1, offset] can ONLY have s9 @offset
251  * while   LD can take s9 (4 byte insn) or LIMM (8 byte insn)
252  */
253 
254 .macro  SET_CURR_TASK_ON_CPU    tsk, tmp
255 	GET_CPU_ID  \tmp
256 	add2 \tmp, @_current_task, \tmp
257 	st   \tsk, [\tmp]
258 #ifdef CONFIG_ARC_CURR_IN_REG
259 	mov r25, \tsk
260 #endif
261 
262 .endm
263 
264 
265 #else   /* Uniprocessor implementation of macros */
266 
267 .macro  GET_CURR_TASK_ON_CPU    reg
268 	ld  \reg, [@_current_task]
269 .endm
270 
271 .macro  SET_CURR_TASK_ON_CPU    tsk, tmp
272 	st  \tsk, [@_current_task]
273 #ifdef CONFIG_ARC_CURR_IN_REG
274 	mov r25, \tsk
275 #endif
276 .endm
277 
278 #endif /* SMP / UNI */
279 
280 /* ------------------------------------------------------------------
281  * Get the ptr to some field of Current Task at @off in task struct
282  *  -Uses r25 for Current task ptr if that is enabled
283  */
284 
285 #ifdef CONFIG_ARC_CURR_IN_REG
286 
287 .macro GET_CURR_TASK_FIELD_PTR  off,  reg
288 	add \reg, r25, \off
289 .endm
290 
291 #else
292 
293 .macro GET_CURR_TASK_FIELD_PTR  off,  reg
294 	GET_CURR_TASK_ON_CPU  \reg
295 	add \reg, \reg, \off
296 .endm
297 
298 #endif	/* CONFIG_ARC_CURR_IN_REG */
299 
300 #else	/* !__ASSEMBLY__ */
301 
302 extern void do_signal(struct pt_regs *);
303 extern void do_notify_resume(struct pt_regs *);
304 extern int do_privilege_fault(unsigned long, struct pt_regs *);
305 extern int do_extension_fault(unsigned long, struct pt_regs *);
306 extern int insterror_is_error(unsigned long, struct pt_regs *);
307 extern int do_memory_error(unsigned long, struct pt_regs *);
308 extern int trap_is_brkpt(unsigned long, struct pt_regs *);
309 extern int do_misaligned_error(unsigned long, struct pt_regs *);
310 extern int do_trap5_error(unsigned long, struct pt_regs *);
311 extern int do_misaligned_access(unsigned long, struct pt_regs *, struct callee_regs *);
312 extern void do_machine_check_fault(unsigned long, struct pt_regs *);
313 extern void do_non_swi_trap(unsigned long, struct pt_regs *);
314 extern void do_insterror_or_kprobe(unsigned long, struct pt_regs *);
315 extern void do_page_fault(unsigned long, struct pt_regs *);
316 
317 #endif
318 
319 #endif  /* __ASM_ARC_ENTRY_H */
320