1/*	$NetBSD: frame.h,v 1.48 2020/08/14 16:18:36 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
 59struct 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
 72struct clockframe {
 73	struct trapframe cf_tf;
 74};
 75
 76/*
 77 * Stack frame. Used during stack traces (db_trace.c)
 78 */
 79struct 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
 87void 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) */		;\
13210:
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#define DO_PENDING_AST(lbl)						;\
1551:	ldr	r1, [r5, #L_MD_ASTPENDING] /* Pending AST? */		;\
156	tst	r1, #1							;\
157	beq	lbl			/* Nope. Just bail */		;\
158	bic	r0, r1, #1		 /* clear AST */		;\
159	str	r0, [r5, #L_MD_ASTPENDING]				;\
160	CPSIE_I(r6, r6)			/* Restore interrupts */	;\
161	mov	r0, sp							;\
162	bl	_C_LABEL(ast)		/* ast(frame) */		;\
163	CPSID_I(r0, r6)			/* Disable interrupts */	;\
164	b	1b			/* test again */
165
166/*
167 * AST_ALIGNMENT_FAULT_LOCALS and ENABLE_ALIGNMENT_FAULTS
168 * These are used in order to support dynamic enabling/disabling of
169 * alignment faults when executing old a.out ARM binaries.
170 *
171 * Note that when ENABLE_ALIGNMENTS_FAULTS finishes r4 will contain
172 * curcpu() and r5 containing curlwp.  DO_AST_AND_RESTORE_ALIGNMENT_FAULTS
173 * relies on r4 and r5 being preserved.
174 */
175#ifdef EXEC_AOUT
176#define	AST_ALIGNMENT_FAULT_LOCALS					\
177.Laflt_cpufuncs:							;\
178	.word	_C_LABEL(cpufuncs)
179
180/*
181 * This macro must be invoked following PUSHFRAMEINSVC or PUSHFRAME at
182 * the top of interrupt/exception handlers.
183 *
184 * When invoked, r0 *must* contain the value of SPSR on the current
185 * trap/interrupt frame. This is always the case if ENABLE_ALIGNMENT_FAULTS
186 * is invoked immediately after PUSHFRAMEINSVC or PUSHFRAME.
187 */
188#define	ENABLE_ALIGNMENT_FAULTS						\
189	and	r7, r0, #(PSR_MODE)	/* Test for USR32 mode */	;\
190	cmp	r7, #(PSR_USR32_MODE)					;\
191	GET_CURX(r4, r5)		/* r4 = curcpu, r5 = curlwp */	;\
192	bne	1f			/* Not USR mode skip AFLT */	;\
193	ldr	r1, [r5, #L_MD_FLAGS]	/* Fetch l_md.md_flags */	;\
194	tst	r1, #MDLWP_NOALIGNFLT					;\
195	beq	1f			/* AFLTs already enabled */	;\
196	ldr	r2, .Laflt_cpufuncs					;\
197	ldr	r1, [r4, #CI_CTRL]	/* Fetch control register */	;\
198	mov	r0, #-1							;\
199	BL_CF_CONTROL(r2)		/* Enable alignment faults */	;\
2001:	/* done */
201
202/*
203 * This macro must be invoked just before PULLFRAMEFROMSVCANDEXIT or
204 * PULLFRAME at the end of interrupt/exception handlers.  We know that
205 * r4 points to curcpu() and r5 points to curlwp since that is what
206 * ENABLE_ALIGNMENT_FAULTS did for us.
207 */
208#define	DO_AST_AND_RESTORE_ALIGNMENT_FAULTS				\
209	DO_PENDING_SOFTINTS						;\
210	GET_CPSR(r6)			/* save CPSR */			;\
211	CPSID_I(r1, r6)			/* Disable interrupts */	;\
212	cmp	r7, #(PSR_USR32_MODE)	/* Returning to USR mode? */	;\
213	bne	3f			/* Nope, get out now */		;\
214	DO_PENDING_AST(2f)		/* Pending AST? */		;\
2152:	ldr	r1, [r4, #CI_CURLWP]	/* get curlwp from cpu_info */	;\
216	ldr	r0, [r1, #L_MD_FLAGS]	/* get md_flags from lwp */	;\
217	tst	r0, #MDLWP_NOALIGNFLT					;\
218	beq	3f			/* Keep AFLTs enabled */	;\
219	ldr	r1, [r4, #CI_CTRL]	/* Fetch control register */	;\
220	ldr	r2, .Laflt_cpufuncs					;\
221	mov	r0, #-1							;\
222	bic	r1, r1, #CPU_CONTROL_AFLT_ENABLE  /* Disable AFLTs */	;\
223	BL_CF_CONTROL(r2)		/* Set new CTRL reg value */	;\
2243:	/* done */
225
226#else	/* !EXEC_AOUT */
227
228#define	AST_ALIGNMENT_FAULT_LOCALS
229
230#define	ENABLE_ALIGNMENT_FAULTS						\
231	and	r7, r0, #(PSR_MODE)	/* Test for USR32 mode */	;\
232	GET_CURX(r4, r5)		/* r4 = curcpu, r5 = curlwp */
233
234
235#define	DO_AST_AND_RESTORE_ALIGNMENT_FAULTS				\
236	DO_PENDING_SOFTINTS						;\
237	GET_CPSR(r6)			/* save CPSR */			;\
238	CPSID_I(r1, r6)			/* Disable interrupts */	;\
239	cmp	r7, #(PSR_USR32_MODE)					;\
240	bne	2f			/* Nope, get out now */		;\
241	DO_PENDING_AST(2f)		/* Pending AST? */		;\
2422:	/* done */
243#endif /* EXEC_AOUT */
244
245#ifndef _ARM_ARCH_6
246#ifdef ARM_LOCK_CAS_DEBUG
247#define	LOCK_CAS_DEBUG_LOCALS						 \
248.L_lock_cas_restart:							;\
249	.word	_C_LABEL(_lock_cas_restart)
250
251#if defined(__ARMEB__)
252#define	LOCK_CAS_DEBUG_COUNT_RESTART					 \
253	ble	99f							;\
254	ldr	r0, .L_lock_cas_restart					;\
255	ldmia	r0, {r1-r2}		/* load ev_count */		;\
256	adds	r2, r2, #1		/* 64-bit incr (lo) */		;\
257	adc	r1, r1, #0		/* 64-bit incr (hi) */		;\
258	stmia	r0, {r1-r2}		/* store ev_count */
259#else /* __ARMEB__ */
260#define	LOCK_CAS_DEBUG_COUNT_RESTART					 \
261	ble	99f							;\
262	ldr	r0, .L_lock_cas_restart					;\
263	ldmia	r0, {r1-r2}		/* load ev_count */		;\
264	adds	r1, r1, #1		/* 64-bit incr (lo) */		;\
265	adc	r2, r2, #0		/* 64-bit incr (hi) */		;\
266	stmia	r0, {r1-r2}		/* store ev_count */
267#endif /* __ARMEB__ */
268#else /* ARM_LOCK_CAS_DEBUG */
269#define	LOCK_CAS_DEBUG_LOCALS		/* nothing */
270#define	LOCK_CAS_DEBUG_COUNT_RESTART	/* nothing */
271#endif /* ARM_LOCK_CAS_DEBUG */
272
273#define	LOCK_CAS_CHECK_LOCALS						 \
274.L_lock_cas:								;\
275	.word	_C_LABEL(_lock_cas)					;\
276.L_lock_cas_end:							;\
277	.word	_C_LABEL(_lock_cas_end)					;\
278LOCK_CAS_DEBUG_LOCALS
279
280#define	LOCK_CAS_CHECK							 \
281	ldr	r0, [sp]		/* get saved PSR */		;\
282	and	r0, r0, #(PSR_MODE)	/* check for SVC32 mode */	;\
283	cmp	r0, #(PSR_SVC32_MODE)					;\
284	bne	99f			/* nope, get out now */		;\
285	ldr	r0, [sp, #(TF_PC)]					;\
286	ldr	r1, .L_lock_cas_end					;\
287	cmp	r0, r1							;\
288	bge	99f							;\
289	ldr	r1, .L_lock_cas						;\
290	cmp	r0, r1							;\
291	strgt	r1, [sp, #(TF_PC)]					;\
292	LOCK_CAS_DEBUG_COUNT_RESTART					;\
29399:
294
295#else
296#define	LOCK_CAS_CHECK			/* nothing */
297#define	LOCK_CAS_CHECK_LOCALS		/* nothing */
298#endif
299
300/*
301 * ASM macros for pushing and pulling trapframes from the stack
302 *
303 * These macros are used to handle the trapframe structure defined above.
304 */
305
306/*
307 * PUSHFRAME - macro to push a trap frame on the stack in the current mode
308 * Since the current mode is used, the SVC lr field is not defined.
309 */
310
311#ifdef CPU_SA110
312/*
313 * NOTE: r13 and r14 are stored separately as a work around for the
314 * SA110 rev 2 STM^ bug
315 */
316#define	PUSHUSERREGS							   \
317	stmia	sp, {r0-r12};		/* Push the user mode registers */ \
318	add	r0, sp, #(TF_USR_SP-TF_R0); /* Adjust the stack pointer */ \
319	stmia	r0, {r13-r14}^		/* Push the user mode registers */
320#else
321#define	PUSHUSERREGS							   \
322	stmia	sp, {r0-r14}^		/* Push the user mode registers */
323#endif
324
325#define PUSHFRAME							   \
326	str	lr, [sp, #-4]!;		/* Push the return address */	   \
327	sub	sp, sp, #(TF_PC-TF_R0);	/* Adjust the stack pointer */	   \
328	PUSHUSERREGS;			/* Push the user mode registers */ \
329	mov     r0, r0;                 /* NOP for previous instruction */ \
330	mrs	r0, spsr;		/* Get the SPSR */		   \
331	str	r0, [sp, #-TF_R0]!	/* Push the SPSR on the stack */
332
333/*
334 * Push a minimal trapframe so we can dispatch an interrupt from the
335 * idle loop.  The only reason the idle loop wakes up is to dispatch
336 * interrupts so why take the avoid of a full exception when we can do
337 * something minimal.
338 */
339#define PUSHIDLEFRAME							   \
340	str	lr, [sp, #-4]!;		/* save SVC32 lr */		   \
341	str	r6, [sp, #(TF_R6-TF_PC)]!; /* save callee-saved r6 */	   \
342	str	r4, [sp, #(TF_R4-TF_R6)]!; /* save callee-saved r4 */	   \
343	mrs	r0, cpsr;		/* Get the CPSR */		   \
344	str	r0, [sp, #(-TF_R4)]!	/* Push the CPSR on the stack */
345
346/*
347 * Push a trapframe to be used by cpu_switchto
348 */
349#define PUSHSWITCHFRAME(rX)						\
350	mov	ip, sp;							\
351	sub	sp, sp, #(TRAPFRAMESIZE-TF_R12); /* Adjust the stack pointer */ \
352	push	{r4-r11};		/* Push the callee saved registers */ \
353	sub	sp, sp, #TF_R4;		/* reserve rest of trapframe */	\
354	str	ip, [sp, #TF_SVC_SP];					\
355	str	lr, [sp, #TF_SVC_LR];					\
356	str	lr, [sp, #TF_PC];					\
357	mrs	rX, cpsr;		/* Get the CPSR */		\
358	str	rX, [sp, #TF_SPSR]	/* save in trapframe */
359
360#define PUSHSWITCHFRAME1						   \
361	mov	ip, sp;							   \
362	sub	sp, sp, #(TRAPFRAMESIZE-TF_R8); /* Adjust the stack pointer */ \
363	push	{r4-r7};		/* Push some of 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
369#if defined(_ARM_ARCH_DWORD_OK) && __ARM_EABI__
370#define	PUSHSWITCHFRAME2						\
371	strd	r10, [sp, #TF_R10];	/* save r10 & r11 */		\
372	strd	r8, [sp, #TF_R8];	/* save r8 & r9 */		\
373	mrs	r0, cpsr;		/* Get the CPSR */		\
374	str	r0, [sp, #TF_SPSR]	/* save in trapframe */
375#else
376#define	PUSHSWITCHFRAME2						\
377	add	r0, sp, #TF_R8;		/* get ptr to r8 and above */	\
378	stmia	r0, {r8-r11};		/* save rest of registers */	\
379	mrs	r0, cpsr;		/* Get the CPSR */		\
380	str	r0, [sp, #TF_SPSR]	/* save in trapframe */
381#endif
382
383/*
384 * PULLFRAME - macro to pull a trap frame from the stack in the current mode
385 * Since the current mode is used, the SVC lr field is ignored.
386 */
387
388#define PULLFRAME							   \
389	ldr     r0, [sp], #TF_R0;	/* Pop the SPSR from stack */	   \
390	msr     spsr_fsxc, r0;						   \
391	ldmia   sp, {r0-r14}^;		/* Restore registers (usr mode) */ \
392	mov     r0, r0;                 /* NOP for previous instruction */ \
393	add	sp, sp, #(TF_PC-TF_R0);	/* Adjust the stack pointer */	   \
394 	ldr	lr, [sp], #4		/* Pop the return address */
395
396#define PULLIDLEFRAME							   \
397	add	sp, sp, #TF_R4;		/* Adjust the stack pointer */	   \
398	ldr	r4, [sp], #(TF_R6-TF_R4); /* restore callee-saved r4 */	   \
399	ldr	r6, [sp], #(TF_PC-TF_R6); /* restore callee-saved r6 */	   \
400 	ldr	lr, [sp], #4		/* Pop the return address */
401
402/*
403 * Pop a trapframe to be used by cpu_switchto (don't touch r0 & r1).
404 */
405#define PULLSWITCHFRAME							\
406	add	sp, sp, #TF_R4;		/* Adjust the stack pointer */	\
407	pop	{r4-r11};		/* pop the callee saved registers */ \
408	add	sp, sp, #(TF_PC-TF_R12); /* Adjust the stack pointer */	\
409	ldr	lr, [sp], #4;		/* pop the return address */
410
411/*
412 * PUSHFRAMEINSVC - macro to push a trap frame on the stack in SVC32 mode
413 * This should only be used if the processor is not currently in SVC32
414 * mode. The processor mode is switched to SVC mode and the trap frame is
415 * stored. The SVC lr field is used to store the previous value of
416 * lr in SVC mode.
417 *
418 * NOTE: r13 and r14 are stored separately as a work around for the
419 * SA110 rev 2 STM^ bug
420 */
421
422#ifdef _ARM_ARCH_6
423#define	SET_CPSR_MODE(tmp, mode)	\
424	cps	#(mode)
425#else
426#define	SET_CPSR_MODE(tmp, mode)	\
427	mrs     tmp, cpsr; 		/* Get the CPSR */		   \
428	bic     tmp, tmp, #(PSR_MODE);	/* Fix for SVC mode */		   \
429	orr     tmp, tmp, #(mode);					   \
430	msr     cpsr_c, tmp		/* Punch into SVC mode */
431#endif
432
433#define PUSHXXXREGSANDSWITCH						   \
434	stmdb	sp, {r0-r3};		/* Save 4 registers */		   \
435	mov	r0, lr;			/* Save xxx32 r14 */		   \
436	mov	r1, sp;			/* Save xxx32 sp */		   \
437	mrs	r3, spsr;		/* Save xxx32 spsr */		   \
438	SET_CPSR_MODE(r2, PSR_SVC32_MODE)
439
440#ifdef KDTRACE_HOOKS
441#define PUSHDTRACEGAP							   \
442	and	r2, r3, #(PSR_MODE);					   \
443	cmp	r2, #(PSR_SVC32_MODE);	/* were we in SVC mode? */	   \
444	mov	r2, sp;							   \
445	subeq	r2, r2, #(4 * 16);	/* if so, leave a gap for dtrace */
446#else
447#define PUSHDTRACEGAP							   \
448	mov	r2, sp
449#endif
450
451#define PUSHTRAPFRAME(rX)						   \
452	bic	r2, rX, #7;		/* Align new SVC sp */		   \
453	str	r0, [r2, #-4]!;		/* Push return address */	   \
454	stmdb	r2!, {sp, lr};		/* Push SVC sp, lr */		   \
455	mov	sp, r2;			/* Keep stack aligned */	   \
456	msr     spsr_fsxc, r3;		/* Restore correct spsr */	   \
457	ldmdb	r1, {r0-r3};		/* Restore 4 regs from xxx mode */ \
458	sub	sp, sp, #(TF_SVC_SP-TF_R0); /* Adjust the stack pointer */ \
459	PUSHUSERREGS;			/* Push the user mode registers */ \
460	mov     r0, r0;                 /* NOP for previous instruction */ \
461	mrs	r0, spsr;		/* Get the SPSR */		   \
462	str	r0, [sp, #-TF_R0]!	/* Push the SPSR onto the stack */
463
464#define PUSHFRAMEINSVC							   \
465	PUSHXXXREGSANDSWITCH;						   \
466	PUSHTRAPFRAME(sp)
467
468/*
469 * PULLFRAMEFROMSVCANDEXIT - macro to pull a trap frame from the stack
470 * in SVC32 mode and restore the saved processor mode and PC.
471 * This should be used when the SVC lr register needs to be restored on
472 * exit.
473 */
474
475#define PULLFRAMEFROMSVCANDEXIT						   \
476	ldr     r0, [sp], #TF_R0;	/* Pop the SPSR from stack */	   \
477	msr     spsr_fsxc, r0;		/* restore SPSR */		   \
478	ldmia   sp, {r0-r14}^;		/* Restore registers (usr mode) */ \
479	mov     r0, r0;	  		/* NOP for previous instruction */ \
480	add	sp, sp, #(TF_SVC_SP-TF_R0); /* Adjust the stack pointer */ \
481	ldmia	sp, {sp, lr, pc}^	/* Restore lr and exit */
482
483#endif /* _LOCORE */
484
485#endif /* _ARM32_FRAME_H_ */