xref: /netbsd-src/sys/arch/arm/include/arm32/frame.h (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: frame.h,v 1.45 2017/07/07 16:59:35 skrll Exp $	*/
2 
3 /*
4  * Copyright (c) 1994-1997 Mark Brinicombe.
5  * Copyright (c) 1994 Brini.
6  * All rights reserved.
7  *
8  * This code is derived from software written for Brini by Mark Brinicombe
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by Brini.
21  * 4. The name of the company nor the name of the author may be used to
22  *    endorse or promote products derived from this software without specific
23  *    prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED
26  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
27  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28  * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
29  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
30  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  * RiscBSD kernel project
38  *
39  * frame.h
40  *
41  * Stack frames structures
42  *
43  * Created      : 30/09/94
44  */
45 
46 #ifndef _ARM32_FRAME_H_
47 #define _ARM32_FRAME_H_
48 
49 #include <arm/frame.h>		/* Common ARM stack frames */
50 
51 #ifndef _LOCORE
52 
53 /*
54  * Switch frame.
55  *
56  * Should be a multiple of 8 bytes for dumpsys.
57  */
58 
59 struct switchframe {
60 	u_int	sf_r4;
61 	u_int	sf_r5;
62 	u_int	sf_r6;
63 	u_int	sf_r7;
64 	u_int	sf_sp;
65 	u_int	sf_pc;
66 };
67 
68 /*
69  * System stack frames.
70  */
71 
72 struct clockframe {
73 	struct trapframe cf_tf;
74 };
75 
76 /*
77  * Stack frame. Used during stack traces (db_trace.c)
78  */
79 struct frame {
80 	u_int	fr_fp;
81 	u_int	fr_sp;
82 	u_int	fr_lr;
83 	u_int	fr_pc;
84 };
85 
86 #ifdef _KERNEL
87 void validate_trapframe(trapframe_t *, int);
88 #endif /* _KERNEL */
89 
90 #else /* _LOCORE */
91 
92 #include "opt_compat_netbsd.h"
93 #include "opt_execfmt.h"
94 #include "opt_multiprocessor.h"
95 #include "opt_cpuoptions.h"
96 #include "opt_arm_debug.h"
97 #include "opt_cputypes.h"
98 #include "opt_dtrace.h"
99 
100 #include <arm/locore.h>
101 
102 /*
103  * This macro is used by DO_AST_AND_RESTORE_ALIGNMENT_FAULTS to process
104  * any pending softints.
105  */
106 #ifdef _ARM_ARCH_4T
107 #define	B_CF_CONTROL(rX)						;\
108 	ldr	ip, [rX, #CF_CONTROL]	/* get function addr */		;\
109 	bx	ip			/* branch to cpu_control */
110 #else
111 #define	B_CF_CONTROL(rX)						;\
112 	ldr	pc, [rX, #CF_CONTROL]	/* branch to cpu_control */
113 #endif
114 #ifdef _ARM_ARCH_5T
115 #define	BL_CF_CONTROL(rX)						;\
116 	ldr	ip, [rX, #CF_CONTROL]	/* get function addr */		;\
117 	blx	ip			/* call cpu_control */
118 #else
119 #define	BL_CF_CONTROL(rX)						;\
120 	mov	lr, pc							;\
121 	ldr	pc, [rX, #CF_CONTROL]	/* call cpu_control */
122 #endif
123 #if defined(__HAVE_FAST_SOFTINTS) && !defined(__HAVE_PIC_FAST_SOFTINTS)
124 #define	DO_PENDING_SOFTINTS						\
125 	ldr	r0, [r4, #CI_INTR_DEPTH]/* Get current intr depth */	;\
126 	cmp	r0, #0			/* Test for 0. */		;\
127 	bne	10f			/*   skip softints if != 0 */	;\
128 	ldr	r0, [r4, #CI_CPL]	/* Get current priority level */;\
129 	ldr	r1, [r4, #CI_SOFTINTS]	/* Get pending softint mask */	;\
130 	lsrs	r0, r1, r0		/* shift mask by cpl */		;\
131 	blne	_C_LABEL(dosoftints)	/* dosoftints(void) */		;\
132 10:
133 #else
134 #define	DO_PENDING_SOFTINTS		/* nothing */
135 #endif
136 
137 #ifdef _ARM_ARCH_6
138 #define	GET_CPSR(rb)			/* nothing */
139 #define	CPSID_I(ra,rb)			cpsid	i
140 #define	CPSIE_I(ra,rb)			cpsie	i
141 #else
142 #define	GET_CPSR(rb)							\
143 	mrs	rb, cpsr		/* fetch CPSR */
144 
145 #define	CPSID_I(ra,rb)							\
146 	orr	ra, rb, #(IF32_bits)					;\
147 	msr	cpsr_c, ra		/* Disable interrupts */
148 
149 #define	CPSIE_I(ra,rb)							\
150 	bic	ra, rb, #(IF32_bits)					;\
151 	msr	cpsr_c, ra		/* Restore interrupts */
152 #endif
153 
154 #ifdef __HAVE_PREEMPTION
155 #define DO_CLEAR_ASTPENDING						\
156 	mvn	r1, #1			/* complement of 1 */		;\
157 	add	r0, r4, #CI_ASTPENDING	/* address of astpending */	;\
158 	bl	_C_LABEL(atomic_and_uint) /* clear AST */
159 #else
160 #define DO_CLEAR_ASTPENDING						\
161 	mov	r0, #0							;\
162 	str	r0, [r4, #CI_ASTPENDING] /* clear AST */
163 #endif
164 
165 #define DO_PENDING_AST(lbl)						;\
166 1:	ldr	r1, [r4, #CI_ASTPENDING] /* Pending AST? */		;\
167 	tst	r1, #0x00000001						;\
168 	beq	lbl			/* Nope. Just bail */		;\
169 	DO_CLEAR_ASTPENDING						;\
170 	CPSIE_I(r5, r5)			/* Restore interrupts */	;\
171 	mov	r0, sp							;\
172 	bl	_C_LABEL(ast)		/* ast(frame) */		;\
173 	CPSID_I(r0, r5)			/* Disable interrupts */	;\
174 	b	1b			/* test again */
175 
176 /*
177  * AST_ALIGNMENT_FAULT_LOCALS and ENABLE_ALIGNMENT_FAULTS
178  * These are used in order to support dynamic enabling/disabling of
179  * alignment faults when executing old a.out ARM binaries.
180  *
181  * Note that when ENABLE_ALIGNMENTS_FAULTS finishes r4 will contain
182  * pointer to the cpu's cpu_info.  DO_AST_AND_RESTORE_ALIGNMENT_FAULTS
183  * relies on r4 being preserved.
184  */
185 #ifdef EXEC_AOUT
186 #define	AST_ALIGNMENT_FAULT_LOCALS					\
187 .Laflt_cpufuncs:							;\
188 	.word	_C_LABEL(cpufuncs)
189 
190 /*
191  * This macro must be invoked following PUSHFRAMEINSVC or PUSHFRAME at
192  * the top of interrupt/exception handlers.
193  *
194  * When invoked, r0 *must* contain the value of SPSR on the current
195  * trap/interrupt frame. This is always the case if ENABLE_ALIGNMENT_FAULTS
196  * is invoked immediately after PUSHFRAMEINSVC or PUSHFRAME.
197  */
198 #define	ENABLE_ALIGNMENT_FAULTS						\
199 	and	r7, r0, #(PSR_MODE)	/* Test for USR32 mode */	;\
200 	cmp	r7, #(PSR_USR32_MODE)					;\
201 	GET_CURCPU(r4)			/* r4 = cpuinfo */		;\
202 	bne	1f			/* Not USR mode skip AFLT */	;\
203 	ldr	r1, [r4, #CI_CURLWP]	/* get curlwp from cpu_info */	;\
204 	ldr	r1, [r1, #L_MD_FLAGS]	/* Fetch l_md.md_flags */	;\
205 	tst	r1, #MDLWP_NOALIGNFLT					;\
206 	beq	1f			/* AFLTs already enabled */	;\
207 	ldr	r2, .Laflt_cpufuncs					;\
208 	ldr	r1, [r4, #CI_CTRL]	/* Fetch control register */	;\
209 	mov	r0, #-1							;\
210 	BL_CF_CONTROL(r2)		/* Enable alignment faults */	;\
211 1:	/* done */
212 
213 /*
214  * This macro must be invoked just before PULLFRAMEFROMSVCANDEXIT or
215  * PULLFRAME at the end of interrupt/exception handlers.  We know that
216  * r4 points to cpu_info since that is what ENABLE_ALIGNMENT_FAULTS did
217  * for use.
218  */
219 #define	DO_AST_AND_RESTORE_ALIGNMENT_FAULTS				\
220 	DO_PENDING_SOFTINTS						;\
221 	GET_CPSR(r5)			/* save CPSR */			;\
222 	CPSID_I(r1, r5)			/* Disable interrupts */	;\
223 	cmp	r7, #(PSR_USR32_MODE)	/* Returning to USR mode? */	;\
224 	bne	3f			/* Nope, get out now */		;\
225 	DO_PENDING_AST(2f)		/* Pending AST? */		;\
226 2:	ldr	r1, [r4, #CI_CURLWP]	/* get curlwp from cpu_info */	;\
227 	ldr	r0, [r1, #L_MD_FLAGS]	/* get md_flags from lwp */	;\
228 	tst	r0, #MDLWP_NOALIGNFLT					;\
229 	beq	3f			/* Keep AFLTs enabled */	;\
230 	ldr	r1, [r4, #CI_CTRL]	/* Fetch control register */	;\
231 	ldr	r2, .Laflt_cpufuncs					;\
232 	mov	r0, #-1							;\
233 	bic	r1, r1, #CPU_CONTROL_AFLT_ENABLE  /* Disable AFLTs */	;\
234 	BL_CF_CONTROL(r2)		/* Set new CTRL reg value */	;\
235 3:	/* done */
236 
237 #else	/* !EXEC_AOUT */
238 
239 #define	AST_ALIGNMENT_FAULT_LOCALS
240 
241 #define	ENABLE_ALIGNMENT_FAULTS						\
242 	and	r7, r0, #(PSR_MODE)	/* Test for USR32 mode */	;\
243 	GET_CURCPU(r4)			/* r4 = cpuinfo */
244 
245 
246 #define	DO_AST_AND_RESTORE_ALIGNMENT_FAULTS				\
247 	DO_PENDING_SOFTINTS						;\
248 	GET_CPSR(r5)			/* save CPSR */			;\
249 	CPSID_I(r1, r5)			/* Disable interrupts */	;\
250 	cmp	r7, #(PSR_USR32_MODE)					;\
251 	bne	2f			/* Nope, get out now */		;\
252 	DO_PENDING_AST(2f)		/* Pending AST? */		;\
253 2:	/* done */
254 #endif /* EXEC_AOUT */
255 
256 #ifndef _ARM_ARCH_6
257 #ifdef ARM_LOCK_CAS_DEBUG
258 #define	LOCK_CAS_DEBUG_LOCALS						 \
259 .L_lock_cas_restart:							;\
260 	.word	_C_LABEL(_lock_cas_restart)
261 
262 #if defined(__ARMEB__)
263 #define	LOCK_CAS_DEBUG_COUNT_RESTART					 \
264 	ble	99f							;\
265 	ldr	r0, .L_lock_cas_restart					;\
266 	ldmia	r0, {r1-r2}		/* load ev_count */		;\
267 	adds	r2, r2, #1		/* 64-bit incr (lo) */		;\
268 	adc	r1, r1, #0		/* 64-bit incr (hi) */		;\
269 	stmia	r0, {r1-r2}		/* store ev_count */
270 #else /* __ARMEB__ */
271 #define	LOCK_CAS_DEBUG_COUNT_RESTART					 \
272 	ble	99f							;\
273 	ldr	r0, .L_lock_cas_restart					;\
274 	ldmia	r0, {r1-r2}		/* load ev_count */		;\
275 	adds	r1, r1, #1		/* 64-bit incr (lo) */		;\
276 	adc	r2, r2, #0		/* 64-bit incr (hi) */		;\
277 	stmia	r0, {r1-r2}		/* store ev_count */
278 #endif /* __ARMEB__ */
279 #else /* ARM_LOCK_CAS_DEBUG */
280 #define	LOCK_CAS_DEBUG_LOCALS		/* nothing */
281 #define	LOCK_CAS_DEBUG_COUNT_RESTART	/* nothing */
282 #endif /* ARM_LOCK_CAS_DEBUG */
283 
284 #define	LOCK_CAS_CHECK_LOCALS						 \
285 .L_lock_cas:								;\
286 	.word	_C_LABEL(_lock_cas)					;\
287 .L_lock_cas_end:							;\
288 	.word	_C_LABEL(_lock_cas_end)					;\
289 LOCK_CAS_DEBUG_LOCALS
290 
291 #define	LOCK_CAS_CHECK							 \
292 	ldr	r0, [sp]		/* get saved PSR */		;\
293 	and	r0, r0, #(PSR_MODE)	/* check for SVC32 mode */	;\
294 	cmp	r0, #(PSR_SVC32_MODE)					;\
295 	bne	99f			/* nope, get out now */		;\
296 	ldr	r0, [sp, #(TF_PC)]					;\
297 	ldr	r1, .L_lock_cas_end					;\
298 	cmp	r0, r1							;\
299 	bge	99f							;\
300 	ldr	r1, .L_lock_cas						;\
301 	cmp	r0, r1							;\
302 	strgt	r1, [sp, #(TF_PC)]					;\
303 	LOCK_CAS_DEBUG_COUNT_RESTART					;\
304 99:
305 
306 #else
307 #define	LOCK_CAS_CHECK			/* nothing */
308 #define	LOCK_CAS_CHECK_LOCALS		/* nothing */
309 #endif
310 
311 /*
312  * ASM macros for pushing and pulling trapframes from the stack
313  *
314  * These macros are used to handle the trapframe structure defined above.
315  */
316 
317 /*
318  * PUSHFRAME - macro to push a trap frame on the stack in the current mode
319  * Since the current mode is used, the SVC lr field is not defined.
320  */
321 
322 #ifdef CPU_SA110
323 /*
324  * NOTE: r13 and r14 are stored separately as a work around for the
325  * SA110 rev 2 STM^ bug
326  */
327 #define	PUSHUSERREGS							   \
328 	stmia	sp, {r0-r12};		/* Push the user mode registers */ \
329 	add	r0, sp, #(TF_USR_SP-TF_R0); /* Adjust the stack pointer */ \
330 	stmia	r0, {r13-r14}^		/* Push the user mode registers */
331 #else
332 #define	PUSHUSERREGS							   \
333 	stmia	sp, {r0-r14}^		/* Push the user mode registers */
334 #endif
335 
336 #define PUSHFRAME							   \
337 	str	lr, [sp, #-4]!;		/* Push the return address */	   \
338 	sub	sp, sp, #(TF_PC-TF_R0);	/* Adjust the stack pointer */	   \
339 	PUSHUSERREGS;			/* Push the user mode registers */ \
340 	mov     r0, r0;                 /* NOP for previous instruction */ \
341 	mrs	r0, spsr;		/* Get the SPSR */		   \
342 	str	r0, [sp, #-TF_R0]!	/* Push the SPSR on the stack */
343 
344 /*
345  * Push a minimal trapframe so we can dispatch an interrupt from the
346  * idle loop.  The only reason the idle loop wakes up is to dispatch
347  * interrupts so why take the avoid of a full exception when we can do
348  * something minimal.
349  */
350 #define PUSHIDLEFRAME							   \
351 	str	lr, [sp, #-4]!;		/* save SVC32 lr */		   \
352 	str	r6, [sp, #(TF_R6-TF_PC)]!; /* save callee-saved r6 */	   \
353 	str	r4, [sp, #(TF_R4-TF_R6)]!; /* save callee-saved r4 */	   \
354 	mrs	r0, cpsr;		/* Get the CPSR */		   \
355 	str	r0, [sp, #(-TF_R4)]!	/* Push the CPSR on the stack */
356 
357 /*
358  * Push a trapframe to be used by cpu_switchto
359  */
360 #define PUSHSWITCHFRAME(rX)						\
361 	mov	ip, sp;							\
362 	sub	sp, sp, #(TRAPFRAMESIZE-TF_R12); /* Adjust the stack pointer */ \
363 	push	{r4-r11};		/* Push the callee saved registers */ \
364 	sub	sp, sp, #TF_R4;		/* reserve rest of trapframe */	\
365 	str	ip, [sp, #TF_SVC_SP];					\
366 	str	lr, [sp, #TF_SVC_LR];					\
367 	str	lr, [sp, #TF_PC];					\
368 	mrs	rX, cpsr;		/* Get the CPSR */		\
369 	str	rX, [sp, #TF_SPSR]	/* save in trapframe */
370 
371 #define PUSHSWITCHFRAME1						   \
372 	mov	ip, sp;							   \
373 	sub	sp, sp, #(TRAPFRAMESIZE-TF_R8); /* Adjust the stack pointer */ \
374 	push	{r4-r7};		/* Push some of the callee saved registers */ \
375 	sub	sp, sp, #TF_R4;		/* reserve rest of trapframe */	\
376 	str	ip, [sp, #TF_SVC_SP];					\
377 	str	lr, [sp, #TF_SVC_LR];					\
378 	str	lr, [sp, #TF_PC]
379 
380 #if defined(_ARM_ARCH_DWORD_OK) && __ARM_EABI__
381 #define	PUSHSWITCHFRAME2						\
382 	strd	r10, [sp, #TF_R10];	/* save r10 & r11 */		\
383 	strd	r8, [sp, #TF_R8];	/* save r8 & r9 */		\
384 	mrs	r0, cpsr;		/* Get the CPSR */		\
385 	str	r0, [sp, #TF_SPSR]	/* save in trapframe */
386 #else
387 #define	PUSHSWITCHFRAME2						\
388 	add	r0, sp, #TF_R8;		/* get ptr to r8 and above */	\
389 	stmia	r0, {r8-r11};		/* save rest of registers */	\
390 	mrs	r0, cpsr;		/* Get the CPSR */		\
391 	str	r0, [sp, #TF_SPSR]	/* save in trapframe */
392 #endif
393 
394 /*
395  * PULLFRAME - macro to pull a trap frame from the stack in the current mode
396  * Since the current mode is used, the SVC lr field is ignored.
397  */
398 
399 #define PULLFRAME							   \
400 	ldr     r0, [sp], #TF_R0;	/* Pop the SPSR from stack */	   \
401 	msr     spsr_fsxc, r0;						   \
402 	ldmia   sp, {r0-r14}^;		/* Restore registers (usr mode) */ \
403 	mov     r0, r0;                 /* NOP for previous instruction */ \
404 	add	sp, sp, #(TF_PC-TF_R0);	/* Adjust the stack pointer */	   \
405  	ldr	lr, [sp], #0x0004	/* Pop the return address */
406 
407 #define PULLIDLEFRAME							   \
408 	add	sp, sp, #TF_R4;		/* Adjust the stack pointer */	   \
409 	ldr	r4, [sp], #(TF_R6-TF_R4); /* restore callee-saved r4 */	   \
410 	ldr	r6, [sp], #(TF_PC-TF_R6); /* restore callee-saved r6 */	   \
411  	ldr	lr, [sp], #4		/* Pop the return address */
412 
413 /*
414  * Pop a trapframe to be used by cpu_switchto (don't touch r0 & r1).
415  */
416 #define PULLSWITCHFRAME							\
417 	add	sp, sp, #TF_R4;		/* Adjust the stack pointer */	\
418 	pop	{r4-r11};		/* pop the callee saved registers */ \
419 	add	sp, sp, #(TF_PC-TF_R12); /* Adjust the stack pointer */	\
420 	ldr	lr, [sp], #4;		/* pop the return address */
421 
422 /*
423  * PUSHFRAMEINSVC - macro to push a trap frame on the stack in SVC32 mode
424  * This should only be used if the processor is not currently in SVC32
425  * mode. The processor mode is switched to SVC mode and the trap frame is
426  * stored. The SVC lr field is used to store the previous value of
427  * lr in SVC mode.
428  *
429  * NOTE: r13 and r14 are stored separately as a work around for the
430  * SA110 rev 2 STM^ bug
431  */
432 
433 #ifdef _ARM_ARCH_6
434 #define	SET_CPSR_MODE(tmp, mode)	\
435 	cps	#(mode)
436 #else
437 #define	SET_CPSR_MODE(tmp, mode)	\
438 	mrs     tmp, cpsr; 		/* Get the CPSR */		   \
439 	bic     tmp, tmp, #(PSR_MODE);	/* Fix for SVC mode */		   \
440 	orr     tmp, tmp, #(mode);					   \
441 	msr     cpsr_c, tmp		/* Punch into SVC mode */
442 #endif
443 
444 #define PUSHXXXREGSANDSWITCH						   \
445 	stmdb	sp, {r0-r3};		/* Save 4 registers */		   \
446 	mov	r0, lr;			/* Save xxx32 r14 */		   \
447 	mov	r1, sp;			/* Save xxx32 sp */		   \
448 	mrs	r3, spsr;		/* Save xxx32 spsr */		   \
449 	SET_CPSR_MODE(r2, PSR_SVC32_MODE)
450 
451 #ifdef KDTRACE_HOOKS
452 #define PUSHDTRACEGAP							   \
453 	and	r2, r3, #(PSR_MODE);					   \
454 	cmp	r2, #(PSR_SVC32_MODE);	/* were we in SVC mode? */	   \
455 	mov	r2, sp;							   \
456 	subeq	r2, r2, #(4 * 16);	/* if so, leave a gap for dtrace */
457 #else
458 #define PUSHDTRACEGAP							   \
459 	mov	r2, sp
460 #endif
461 
462 #define PUSHTRAPFRAME(rX)						   \
463 	bic	r2, rX, #7;		/* Align new SVC sp */		   \
464 	str	r0, [r2, #-4]!;		/* Push return address */	   \
465 	stmdb	r2!, {sp, lr};		/* Push SVC sp, lr */		   \
466 	mov	sp, r2;			/* Keep stack aligned */	   \
467 	msr     spsr_fsxc, r3;		/* Restore correct spsr */	   \
468 	ldmdb	r1, {r0-r3};		/* Restore 4 regs from xxx mode */ \
469 	sub	sp, sp, #(TF_SVC_SP-TF_R0); /* Adjust the stack pointer */ \
470 	PUSHUSERREGS;			/* Push the user mode registers */ \
471 	mov     r0, r0;                 /* NOP for previous instruction */ \
472 	mrs	r0, spsr;		/* Get the SPSR */		   \
473 	str	r0, [sp, #-TF_R0]!	/* Push the SPSR onto the stack */
474 
475 #define PUSHFRAMEINSVC							   \
476 	PUSHXXXREGSANDSWITCH;						   \
477 	PUSHTRAPFRAME(sp)
478 
479 /*
480  * PULLFRAMEFROMSVCANDEXIT - macro to pull a trap frame from the stack
481  * in SVC32 mode and restore the saved processor mode and PC.
482  * This should be used when the SVC lr register needs to be restored on
483  * exit.
484  */
485 
486 #define PULLFRAMEFROMSVCANDEXIT						   \
487 	ldr     r0, [sp], #0x0008;	/* Pop the SPSR from stack */	   \
488 	msr     spsr_fsxc, r0;		/* restore SPSR */		   \
489 	ldmia   sp, {r0-r14}^;		/* Restore registers (usr mode) */ \
490 	mov     r0, r0;	  		/* NOP for previous instruction */ \
491 	add	sp, sp, #(TF_SVC_SP-TF_R0); /* Adjust the stack pointer */ \
492 	ldmia	sp, {sp, lr, pc}^	/* Restore lr and exit */
493 
494 #endif /* _LOCORE */
495 
496 #endif /* _ARM32_FRAME_H_ */
497