xref: /openbsd-src/sys/arch/arm/include/frame.h (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: frame.h,v 1.10 2016/04/25 08:00:43 patrick Exp $	*/
2 /*	$NetBSD: frame.h,v 1.9 2003/12/01 08:48:33 scw Exp $	*/
3 
4 /*
5  * Copyright (c) 1994-1997 Mark Brinicombe.
6  * Copyright (c) 1994 Brini.
7  * All rights reserved.
8  *
9  * This code is derived from software written for Brini by Mark Brinicombe
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by Brini.
22  * 4. The name of the company nor the name of the author may be used to
23  *    endorse or promote products derived from this software without specific
24  *    prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED
27  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
28  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29  * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
30  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
31  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
32  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  * RiscBSD kernel project
39  *
40  * frame.h
41  *
42  * Stack frames structures
43  *
44  * Created      : 30/09/94
45  */
46 
47 #ifndef _ARM_FRAME_H_
48 #define _ARM_FRAME_H_
49 
50 #ifndef _LOCORE
51 
52 #include <sys/signal.h>
53 
54 /*
55  * Trap frame.  Pushed onto the kernel stack on a trap (synchronous exception).
56  */
57 
58 typedef struct trapframe {
59 	register_t tf_spsr;
60 	register_t tf_r0;
61 	register_t tf_r1;
62 	register_t tf_r2;
63 	register_t tf_r3;
64 	register_t tf_r4;
65 	register_t tf_r5;
66 	register_t tf_r6;
67 	register_t tf_r7;
68 	register_t tf_r8;
69 	register_t tf_r9;
70 	register_t tf_r10;
71 	register_t tf_r11;
72 	register_t tf_r12;
73 	register_t tf_usr_sp;
74 	register_t tf_usr_lr;
75 	register_t tf_svc_sp;
76 	register_t tf_svc_lr;
77 	register_t tf_pc;
78 	register_t tf_pad;
79 } trapframe_t;
80 
81 /* Register numbers */
82 #define tf_r13 tf_usr_sp
83 #define tf_r14 tf_usr_lr
84 #define tf_r15 tf_pc
85 
86 /*
87  * Signal frame.  Pushed onto user stack before calling sigcode.
88  */
89 
90 struct sigframe {
91 	int	sf_signum;
92 	siginfo_t *sf_sip;
93 	struct	sigcontext *sf_scp;
94 	sig_t	sf_handler;
95 	struct	sigcontext sf_sc;
96 	siginfo_t sf_si;
97 };
98 
99 /* the pointers are used in the trampoline code to locate the ucontext */
100 #if 0
101 struct sigframe_siginfo {
102 	siginfo_t	sf_si;		/* actual saved siginfo */
103 	ucontext_t	sf_uc;		/* actual saved ucontext */
104 };
105 #endif
106 
107 #if 0
108 #ifdef _KERNEL
109 void sendsig_sigcontext(const ksiginfo_t *, const sigset_t *);
110 #endif
111 #endif
112 
113 #endif /* _LOCORE */
114 
115 #ifndef _LOCORE
116 
117 /*
118  * System stack frames.
119  */
120 
121 typedef struct irqframe {
122 	unsigned int if_spsr;
123 	unsigned int if_r0;
124 	unsigned int if_r1;
125 	unsigned int if_r2;
126 	unsigned int if_r3;
127 	unsigned int if_r4;
128 	unsigned int if_r5;
129 	unsigned int if_r6;
130 	unsigned int if_r7;
131 	unsigned int if_r8;
132 	unsigned int if_r9;
133 	unsigned int if_r10;
134 	unsigned int if_r11;
135 	unsigned int if_r12;
136 	unsigned int if_usr_sp;
137 	unsigned int if_usr_lr;
138 	unsigned int if_svc_sp;
139 	unsigned int if_svc_lr;
140 	unsigned int if_pc;
141 	unsigned int if_pad;
142 } irqframe_t;
143 
144 #define clockframe irqframe
145 
146 /*
147  * Switch frame
148  */
149 
150 struct switchframe {
151 	u_int	sf_pad;
152 	u_int	sf_r4;
153 	u_int	sf_r5;
154 	u_int	sf_r6;
155 	u_int	sf_r7;
156 	u_int	sf_pc;
157 };
158 
159 /*
160  * Stack frame. Used during stack traces (db_trace.c)
161  */
162 struct frame {
163 	u_int	fr_fp;
164 	u_int	fr_sp;
165 	u_int	fr_lr;
166 	u_int	fr_pc;
167 };
168 
169 #else /* _LOCORE */
170 
171 #define	AST_LOCALS							 \
172 .Laflt_astpending:							;\
173 	.word	_C_LABEL(astpending)
174 
175 #define	DO_AST								 \
176 	ldr	r0, [sp]		/* Get the SPSR from stack */	;\
177 	mrs	r4, cpsr		/* save CPSR */			;\
178 	and	r0, r0, #(PSR_MODE)	/* Returning to USR mode? */	;\
179 	teq	r0, #(PSR_USR32_MODE)					;\
180 	ldreq	r5, .Laflt_astpending					;\
181 	bne	2f			/* Nope, get out now */		;\
182 	bic	r4, r4, #(PSR_I)					;\
183 1:	orr	r0, r4, #(PSR_I)	/* Disable IRQs */		;\
184 	msr	cpsr_c, r0						;\
185 	ldr	r1, [r5]		/* Pending AST? */		;\
186 	teq	r1, #0x00000000						;\
187 	beq	2f			/* Nope. Just bail */		;\
188 	mov	r1, #0x00000000						;\
189 	str	r1, [r5]		/* Clear astpending */		;\
190 	msr	cpsr_c, r4		/* Restore interrupts */	;\
191 	mov	r0, sp							;\
192 	adr	lr, 1b							;\
193 	b	_C_LABEL(ast)		/* ast(frame) */		;\
194 2:
195 
196 /*
197  * ASM macros for pushing and pulling trapframes from the stack
198  *
199  * These macros are used to handle the irqframe and trapframe structures
200  * defined above.
201  */
202 
203 /*
204  * CLREX - On ARMv7 machines that support atomic instructions, we need
205  * to clear the exclusive monitors on kernel exit, so that a userland
206  * atomic store can't succeed due to an unrelated outstanding atomic
207  * operation. ARM also highly recommends clearing the monitor on data
208  * aborts, as the monitor state after taking a data abort is unknown.
209  * Issuing a clrex on kernel entry and on kernel exit is the easiest
210  * way to take care of both issues and to make sure that the kernel
211  * and userland do not leave any outstanding reserves active.
212  */
213 #if defined(CPU_ARMv7)
214 #define CLREX clrex
215 #else
216 #define CLREX
217 #endif
218 
219 /*
220  * PUSHFRAME - macro to push a trap frame on the stack in the current mode
221  * Since the current mode is used, the SVC lr field is not defined.
222  */
223 
224 #define PUSHFRAME							   \
225 	CLREX;								   \
226 	sub	sp, sp, #4;		/* Align the stack */		   \
227 	str	lr, [sp, #-4]!;		/* Push the return address */	   \
228 	sub	sp, sp, #(4*17);	/* Adjust the stack pointer */	   \
229 	stmia	sp, {r0-r14}^;		/* Push the user mode registers */ \
230 	mov	r0, r0;			/* NOP for previous instruction */ \
231 	mrs	r0, spsr;		/* Put the SPSR on the stack */	   \
232 	str	r0, [sp, #-4]!
233 
234 /*
235  * PULLFRAME - macro to pull a trap frame from the stack in the current mode
236  * Since the current mode is used, the SVC lr field is ignored.
237  */
238 
239 #define PULLFRAME							   \
240 	CLREX;								   \
241 	ldr	r0, [sp], #0x0004;	/* Get the SPSR from stack */	   \
242 	msr	spsr_fsxc, r0;						   \
243 	ldmia	sp, {r0-r14}^;		/* Restore registers (usr mode) */ \
244 	mov	r0, r0;			/* NOP for previous instruction */ \
245 	add	sp, sp, #(4*17);	/* Adjust the stack pointer */	   \
246 	ldr	lr, [sp], #0x0004;	/* Pull the return address */	   \
247 	add	sp, sp, #4		/* Align the stack */
248 
249 /*
250  * PUSHFRAMEINSVC - macro to push a trap frame on the stack in SVC32 mode
251  * This should only be used if the processor is not currently in SVC32
252  * mode. The processor mode is switched to SVC mode and the trap frame is
253  * stored. The SVC lr field is used to store the previous value of
254  * lr in SVC mode.
255  */
256 
257 #define PUSHFRAMEINSVC							   \
258 	CLREX;								   \
259 	stmdb	sp, {r0-r3};		/* Save 4 registers */		   \
260 	mov	r0, lr;			/* Save xxx32 r14 */		   \
261 	mov	r1, sp;			/* Save xxx32 sp */		   \
262 	mrs	r3, spsr;		/* Save xxx32 spsr */		   \
263 	mrs	r2, cpsr; 		/* Get the CPSR */		   \
264 	bic	r2, r2, #(PSR_MODE);	/* Fix for SVC mode */		   \
265 	orr	r2, r2, #(PSR_SVC32_MODE);				   \
266 	msr	cpsr_c, r2;		/* Punch into SVC mode */	   \
267 	mov	r2, sp;			/* Save	SVC sp */		   \
268 	bic	sp, sp, #7;		/* Align sp to an 8-byte address */   \
269 	sub	sp, sp, #4;		/* Pad trapframe to keep alignment */ \
270 	str	r0, [sp, #-4]!;		/* Push return address */	   \
271 	str	lr, [sp, #-4]!;		/* Push SVC lr */		   \
272 	str	r2, [sp, #-4]!;		/* Push SVC sp */		   \
273 	msr	spsr_fsxc, r3;		/* Restore correct spsr */	   \
274 	ldmdb	r1, {r0-r3};		/* Restore 4 regs from xxx mode */ \
275 	sub	sp, sp, #(4*15);	/* Adjust the stack pointer */	   \
276 	stmia	sp, {r0-r14}^;		/* Push the user mode registers */ \
277 	mov	r0, r0;			/* NOP for previous instruction */ \
278 	mrs	r0, spsr;		/* Put the SPSR on the stack */	   \
279 	str	r0, [sp, #-4]!
280 
281 /*
282  * PULLFRAMEFROMSVCANDEXIT - macro to pull a trap frame from the stack
283  * in SVC32 mode and restore the saved processor mode and PC.
284  * This should be used when the SVC lr register needs to be restored on
285  * exit.
286  */
287 
288 #define PULLFRAMEFROMSVCANDEXIT						   \
289 	CLREX;								   \
290 	ldr	r0, [sp], #0x0004;	/* Get the SPSR from stack */	   \
291 	msr	spsr_fsxc, r0;		/* restore SPSR */		   \
292 	ldmia	sp, {r0-r14}^;		/* Restore registers (usr mode) */ \
293 	mov	r0, r0;			/* NOP for previous instruction */ \
294 	add	sp, sp, #(4*15);	/* Adjust the stack pointer */	   \
295 	ldmia	sp, {sp, lr, pc}^	/* Restore lr and exit */
296 
297 #endif /* _LOCORE */
298 
299 #endif /* _ARM_FRAME_H_ */
300 
301 /* End of frame.h */
302