xref: /openbmc/linux/arch/arc/include/asm/entry.h (revision a9ebfc40)
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_R25
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 	PUSH	r25
108 .endm
109 
110 .macro RESTORE_R25_TO_R13
111 	POP	r25
112 	POP	r24
113 	POP	r23
114 	POP	r22
115 	POP	r21
116 	POP	r20
117 	POP	r19
118 	POP	r18
119 	POP	r17
120 	POP	r16
121 	POP	r15
122 	POP	r14
123 	POP	r13
124 .endm
125 
126 /*
127  * save user mode callee regs as struct callee_regs
128  *  - needed by fork/do_signal/unaligned-access-emulation.
129  */
130 .macro SAVE_CALLEE_SAVED_USER
131 	SAVE_R13_TO_R25
132 .endm
133 
134 /*
135  * restore user mode callee regs as struct callee_regs
136  *  - could have been changed by ptrace tracer or unaligned-access fixup
137  */
138 .macro RESTORE_CALLEE_SAVED_USER
139 	RESTORE_R25_TO_R13
140 .endm
141 
142 /*
143  * save/restore kernel mode callee regs at the time of context switch
144  */
145 .macro SAVE_CALLEE_SAVED_KERNEL
146 	SAVE_R13_TO_R25
147 .endm
148 
149 .macro RESTORE_CALLEE_SAVED_KERNEL
150 	RESTORE_R25_TO_R13
151 .endm
152 
153 /*--------------------------------------------------------------
154  * Super FAST Restore callee saved regs by simply re-adjusting SP
155  *-------------------------------------------------------------*/
156 .macro DISCARD_CALLEE_SAVED_USER
157 	add     sp, sp, SZ_CALLEE_REGS
158 .endm
159 
160 /*-------------------------------------------------------------
161  * given a tsk struct, get to the base of it's kernel mode stack
162  * tsk->thread_info is really a PAGE, whose bottom hoists stack
163  * which grows upwards towards thread_info
164  *------------------------------------------------------------*/
165 
166 .macro GET_TSK_STACK_BASE tsk, out
167 
168 	/* Get task->thread_info (this is essentially start of a PAGE) */
169 	ld  \out, [\tsk, TASK_THREAD_INFO]
170 
171 	/* Go to end of page where stack begins (grows upwards) */
172 	add2 \out, \out, (THREAD_SIZE)/4
173 
174 .endm
175 
176 /*
177  * @reg [OUT] thread_info->flags of "current"
178  */
179 .macro GET_CURR_THR_INFO_FLAGS  reg
180 	GET_CURR_THR_INFO_FROM_SP  \reg
181 	ld  \reg, [\reg, THREAD_INFO_FLAGS]
182 .endm
183 
184 #ifdef CONFIG_SMP
185 
186 /*
187  * Retrieve the current running task on this CPU
188  *  - loads it from backing _current_task[] (and can't use the
189  *    caching reg for current task
190  */
191 .macro  GET_CURR_TASK_ON_CPU   reg
192 	GET_CPU_ID  \reg
193 	ld.as  \reg, [@_current_task, \reg]
194 .endm
195 
196 /*-------------------------------------------------
197  * Save a new task as the "current" task on this CPU
198  * 1. Determine curr CPU id.
199  * 2. Use it to index into _current_task[ ]
200  *
201  * Coded differently than GET_CURR_TASK_ON_CPU (which uses LD.AS)
202  * because ST r0, [r1, offset] can ONLY have s9 @offset
203  * while   LD can take s9 (4 byte insn) or LIMM (8 byte insn)
204  */
205 
206 .macro  SET_CURR_TASK_ON_CPU    tsk, tmp
207 	GET_CPU_ID  \tmp
208 	add2 \tmp, @_current_task, \tmp
209 	st   \tsk, [\tmp]
210 #ifdef CONFIG_ARC_CURR_IN_REG
211 	mov gp, \tsk
212 #endif
213 
214 .endm
215 
216 
217 #else   /* Uniprocessor implementation of macros */
218 
219 .macro  GET_CURR_TASK_ON_CPU    reg
220 	ld  \reg, [@_current_task]
221 .endm
222 
223 .macro  SET_CURR_TASK_ON_CPU    tsk, tmp
224 	st  \tsk, [@_current_task]
225 #ifdef CONFIG_ARC_CURR_IN_REG
226 	mov gp, \tsk
227 #endif
228 .endm
229 
230 #endif /* SMP / UNI */
231 
232 /*
233  * Get the ptr to some field of Current Task at @off in task struct
234  *  - Uses current task cached in reg if enabled
235  */
236 #ifdef CONFIG_ARC_CURR_IN_REG
237 
238 .macro GET_CURR_TASK_FIELD_PTR  off,  reg
239 	add \reg, gp, \off
240 .endm
241 
242 #else
243 
244 .macro GET_CURR_TASK_FIELD_PTR  off,  reg
245 	GET_CURR_TASK_ON_CPU  \reg
246 	add \reg, \reg, \off
247 .endm
248 
249 #endif	/* CONFIG_ARC_CURR_IN_REG */
250 
251 #else	/* !__ASSEMBLY__ */
252 
253 extern void do_signal(struct pt_regs *);
254 extern void do_notify_resume(struct pt_regs *);
255 extern int do_privilege_fault(unsigned long, struct pt_regs *);
256 extern int do_extension_fault(unsigned long, struct pt_regs *);
257 extern int insterror_is_error(unsigned long, struct pt_regs *);
258 extern int do_memory_error(unsigned long, struct pt_regs *);
259 extern int trap_is_brkpt(unsigned long, struct pt_regs *);
260 extern int do_misaligned_error(unsigned long, struct pt_regs *);
261 extern int do_trap5_error(unsigned long, struct pt_regs *);
262 extern int do_misaligned_access(unsigned long, struct pt_regs *, struct callee_regs *);
263 extern void do_machine_check_fault(unsigned long, struct pt_regs *);
264 extern void do_non_swi_trap(unsigned long, struct pt_regs *);
265 extern void do_insterror_or_kprobe(unsigned long, struct pt_regs *);
266 extern void do_page_fault(unsigned long, struct pt_regs *);
267 
268 #endif
269 
270 #endif  /* __ASM_ARC_ENTRY_H */
271