2 * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
3 * Copyright (C) 2007-2009 PetaLogix
4 * Copyright (C) 2006 Atmark Techno, Inc.
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
11 #include <linux/linkage.h>
12 #include <asm/thread_info.h>
13 #include <linux/errno.h>
14 #include <asm/entry.h>
15 #include <asm/asm-offsets.h>
16 #include <asm/registers.h>
17 #include <asm/unistd.h>
18 #include <asm/percpu.h>
19 #include <asm/signal.h>
21 #if CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR
36 andi r11, r11, ~MSR_IE
48 andi r11, r11, ~MSR_BIP
54 swi r1, r0, PER_CPU(ENTRY_SP) /* save the current sp */
55 swi r11, r0, PER_CPU(R11_SAVE) /* temporarily save r11 */
56 lwi r11, r0, PER_CPU(KM) /* load mode indicator */
59 brid 2f /* jump over */
60 addik r1, r1, (-PT_SIZE) /* room for pt_regs (delay slot) */
61 1: /* switch to kernel stack */
62 lwi r1, r0, PER_CPU(CURRENT_SAVE) /* get the saved current */
63 lwi r1, r1, TS_THREAD_INFO /* get the thread info */
64 /* calculate kernel stack pointer */
65 addik r1, r1, THREAD_SIZE - PT_SIZE
67 swi r11, r1, PT_MODE /* store the mode */
68 lwi r11, r0, PER_CPU(R11_SAVE) /* reload r11 */
100 /* special purpose registers */
109 /* reload original stack pointer and save it */
110 lwi r11, r0, PER_CPU(ENTRY_SP)
112 /* update mode indicator we are in kernel mode */
114 swi r11, r0, PER_CPU(KM)
116 lwi r31, r0, PER_CPU(CURRENT_SAVE)
117 /* prepare the link register, the argument and jump */
118 addik r15, r0, ret_from_intr - 8
125 bneid r11, no_intr_resched
127 lwi r6, r31, TS_THREAD_INFO /* get thread info */
128 lwi r19, r6, TI_FLAGS /* get flags in thread info */
129 /* do an extra work if any bits are set */
131 andi r11, r19, _TIF_NEED_RESCHED
135 1: andi r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME
136 beqid r11, no_intr_resched
138 bralid r15, do_notify_resume
142 /* Disable interrupts, we are now committed to the state restore */
145 /* save mode indicator */
147 swi r11, r0, PER_CPU(KM)
150 swi r31, r0, PER_CPU(CURRENT_SAVE)
152 /* special purpose registers */
199 ENTRY(_user_exception)
200 swi r1, r0, PER_CPU(ENTRY_SP) /* save the current sp */
201 swi r11, r0, PER_CPU(R11_SAVE) /* temporarily save r11 */
202 lwi r11, r0, PER_CPU(KM) /* load mode indicator */
203 beqid r11, 1f /* Already in kernel mode? */
205 brid 2f /* jump over */
206 addik r1, r1, (-PT_SIZE) /* Room for pt_regs (delay slot) */
207 1: /* Switch to kernel stack */
208 lwi r1, r0, PER_CPU(CURRENT_SAVE) /* get the saved current */
209 lwi r1, r1, TS_THREAD_INFO /* get the thread info */
210 /* calculate kernel stack pointer */
211 addik r1, r1, THREAD_SIZE - PT_SIZE
213 swi r11, r1, PT_MODE /* store the mode */
214 lwi r11, r0, PER_CPU(R11_SAVE) /* reload r11 */
215 /* save them on stack */
217 swi r3, r1, PT_R3 /* r3: _always_ in clobber list; see unistd.h */
218 swi r4, r1, PT_R4 /* r4: _always_ in clobber list; see unistd.h */
226 /* r12: _always_ in clobber list; see unistd.h */
229 /* r14: _always_ in clobber list; see unistd.h */
231 /* but we want to return to the next inst. */
233 swi r14, r1, PT_PC /* increment by 4 and store in pc */
253 nop /* make sure IE bit is in effect */
254 clear_bip /* once IE is in effect it is safe to clear BIP */
257 /* special purpose registers */
266 /* reload original stack pointer and save it */
267 lwi r11, r0, PER_CPU(ENTRY_SP)
269 /* update mode indicator we are in kernel mode */
271 swi r11, r0, PER_CPU(KM)
273 lwi r31, r0, PER_CPU(CURRENT_SAVE)
274 /* re-enable interrupts now we are in kernel mode */
277 /* See if the system call number is valid. */
278 addi r11, r12, -__NR_syscalls
279 bgei r11, 1f /* return to user if not valid */
280 /* Figure out which function to use for this system call. */
281 /* Note Microblaze barrel shift is optional, so don't rely on it */
282 add r12, r12, r12 /* convert num -> ptr */
283 addik r30, r0, 1 /* restarts allowed */
285 lwi r12, r12, sys_call_table /* Get function pointer */
286 addik r15, r0, ret_to_user-8 /* set return address */
287 bra r12 /* Make the system call. */
288 bri 0 /* won't reach here */
290 brid ret_to_user /* jump to syscall epilogue */
291 addi r3, r0, -ENOSYS /* set errno in delay slot */
294 * Debug traps are like a system call, but entered via brki r14, 0x60
295 * All we need to do is send the SIGTRAP signal to current, ptrace and
296 * do_notify_resume will handle the rest
298 ENTRY(_debug_exception)
299 swi r1, r0, PER_CPU(ENTRY_SP) /* save the current sp */
300 lwi r1, r0, PER_CPU(CURRENT_SAVE) /* get the saved current */
301 lwi r1, r1, TS_THREAD_INFO /* get the thread info */
302 addik r1, r1, THREAD_SIZE - PT_SIZE /* get the kernel stack */
303 swi r11, r0, PER_CPU(R11_SAVE) /* temporarily save r11 */
304 lwi r11, r0, PER_CPU(KM) /* load mode indicator */
306 swi r11, r1, PT_MODE /* store the mode */
307 lwi r11, r0, PER_CPU(R11_SAVE) /* reload r11 */
308 /* save them on stack */
310 swi r3, r1, PT_R3 /* r3: _always_ in clobber list; see unistd.h */
311 swi r4, r1, PT_R4 /* r4: _always_ in clobber list; see unistd.h */
319 /* r12: _always_ in clobber list; see unistd.h */
322 /* r14: _always_ in clobber list; see unistd.h */
324 swi r14, r1, PT_PC /* Will return to interrupted instruction */
344 nop /* make sure IE bit is in effect */
345 clear_bip /* once IE is in effect it is safe to clear BIP */
348 /* special purpose registers */
357 /* reload original stack pointer and save it */
358 lwi r11, r0, PER_CPU(ENTRY_SP)
360 /* update mode indicator we are in kernel mode */
362 swi r11, r0, PER_CPU(KM)
364 lwi r31, r0, PER_CPU(CURRENT_SAVE)
365 /* re-enable interrupts now we are in kernel mode */
368 addi r5, r0, SIGTRAP /* sending the trap signal */
369 add r6, r0, r31 /* to current */
371 add r7, r0, r0 /* 3rd param zero */
373 addik r30, r0, 1 /* restarts allowed ??? */
374 /* Restore r3/r4 to work around how ret_to_user works */
382 /* struct task_struct *_switch_to(struct thread_info *prev,
383 struct thread_info *next); */
385 /* prepare return value */
388 /* save registers in cpu_context */
389 /* use r11 and r12, volatile registers, as temp register */
390 addik r11, r5, TI_CPU_CONTEXT
393 /* skip volatile registers.
394 * they are saved on stack when we jumped to _switch_to() */
395 /* dedicated registers */
402 /* save non-volatile registers */
415 /* special purpose registers */
425 /* update r31, the current */
427 swi r31, r0, PER_CPU(CURRENT_SAVE)
429 /* get new process' cpu context and restore */
430 addik r11, r6, TI_CPU_CONTEXT
432 /* special purpose registers */
441 /* non-volatile registers */
454 /* dedicated registers */
461 /* skip volatile registers */
470 brlid r15, schedule_tail
472 swi r31, r1, PT_R31 /* save r31 in user context. */
473 /* will soon be restored to r31 in ret_to_user */
478 ENTRY(ret_from_kernel_thread)
479 brlid r15, schedule_tail
491 andi r11, r19, _TIF_NEED_RESCHED
495 1: andi r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME
496 beqi r11, no_work_pending
498 bralid r15, do_notify_resume
505 swi r4, r1, PT_R4 /* return val */
506 swi r3, r1, PT_R3 /* return val */
508 lwi r6, r31, TS_THREAD_INFO /* get thread info */
509 lwi r19, r6, TI_FLAGS /* get flags in thread info */
510 bnei r19, work_pending /* do an extra work if any bits are set */
516 swi r31, r0, PER_CPU(CURRENT_SAVE)
517 /* save mode indicator */
519 swi r18, r0, PER_CPU(KM)
521 /* special purpose registers */
558 lwi r4, r1, PT_R4 /* return val */
559 lwi r3, r1, PT_R3 /* return val */
566 sys_rt_sigreturn_wrapper:
567 addk r30, r0, r0 /* no restarts for this one */
568 brid sys_rt_sigreturn
571 /* Interrupt vector table */
572 .section .init.ivt, "ax"
578 brai _hw_exception_handler
580 brai _debug_exception
583 #include "syscall_table.S"
585 syscall_table_size=(.-sys_call_table)
592 .ascii "IRQ (PREEMPTED)\0"
593 type_SYSCALL_PREEMPT:
594 .ascii " SYSCALL (PREEMPTED)\0"
597 * Trap decoding for stack unwinder
598 * Tuples are (start addr, end addr, string)
599 * If return address lies on [start addr, end addr],
600 * unwinder displays 'string'
604 .global microblaze_trap_handlers
605 microblaze_trap_handlers:
606 /* Exact matches come first */
607 .word ret_to_user ; .word ret_to_user ; .word type_SYSCALL
608 .word ret_from_intr; .word ret_from_intr ; .word type_IRQ
609 /* Fuzzy matches go here */
610 .word ret_from_intr; .word no_intr_resched; .word type_IRQ_PREEMPT
611 .word work_pending ; .word no_work_pending; .word type_SYSCALL_PREEMPT
613 .word 0 ; .word 0 ; .word 0