1/*
2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
3 *
4 *   This program is free software; you can redistribute it and/or
5 *   modify it under the terms of the GNU General Public License
6 *   as published by the Free Software Foundation, version 2.
7 *
8 *   This program is distributed in the hope that it will be useful, but
9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 *   NON INFRINGEMENT.  See the GNU General Public License for
12 *   more details.
13 *
14 * Linux interrupt vectors.
15 */
16
17#include <linux/linkage.h>
18#include <linux/errno.h>
19#include <linux/init.h>
20#include <linux/unistd.h>
21#include <asm/ptrace.h>
22#include <asm/thread_info.h>
23#include <asm/irqflags.h>
24#include <asm/atomic.h>
25#include <asm/asm-offsets.h>
26#include <hv/hypervisor.h>
27#include <arch/abi.h>
28#include <arch/interrupts.h>
29#include <arch/spr_def.h>
30
31#ifdef CONFIG_PREEMPT
32# error "No support for kernel preemption currently"
33#endif
34
35#define PTREGS_PTR(reg, ptreg) addli reg, sp, C_ABI_SAVE_AREA_SIZE + (ptreg)
36
37#define PTREGS_OFFSET_SYSCALL PTREGS_OFFSET_REG(TREG_SYSCALL_NR)
38
39#if !CHIP_HAS_WH64()
40	/* By making this an empty macro, we can use wh64 in the code. */
41	.macro  wh64 reg
42	.endm
43#endif
44
45	.macro  push_reg reg, ptr=sp, delta=-4
46	{
47	 sw     \ptr, \reg
48	 addli  \ptr, \ptr, \delta
49	}
50	.endm
51
52	.macro  pop_reg reg, ptr=sp, delta=4
53	{
54	 lw     \reg, \ptr
55	 addli  \ptr, \ptr, \delta
56	}
57	.endm
58
59	.macro  pop_reg_zero reg, zreg, ptr=sp, delta=4
60	{
61	 move   \zreg, zero
62	 lw     \reg, \ptr
63	 addi   \ptr, \ptr, \delta
64	}
65	.endm
66
67	.macro  push_extra_callee_saves reg
68	PTREGS_PTR(\reg, PTREGS_OFFSET_REG(51))
69	push_reg r51, \reg
70	push_reg r50, \reg
71	push_reg r49, \reg
72	push_reg r48, \reg
73	push_reg r47, \reg
74	push_reg r46, \reg
75	push_reg r45, \reg
76	push_reg r44, \reg
77	push_reg r43, \reg
78	push_reg r42, \reg
79	push_reg r41, \reg
80	push_reg r40, \reg
81	push_reg r39, \reg
82	push_reg r38, \reg
83	push_reg r37, \reg
84	push_reg r36, \reg
85	push_reg r35, \reg
86	push_reg r34, \reg, PTREGS_OFFSET_BASE - PTREGS_OFFSET_REG(34)
87	.endm
88
89	.macro  panic str
90	.pushsection .rodata, "a"
911:
92	.asciz  "\str"
93	.popsection
94	{
95	 moveli r0, lo16(1b)
96	}
97	{
98	 auli   r0, r0, ha16(1b)
99	 jal    panic
100	}
101	.endm
102
103#ifdef __COLLECT_LINKER_FEEDBACK__
104	.pushsection .text.intvec_feedback,"ax"
105intvec_feedback:
106	.popsection
107#endif
108
109	/*
110	 * Default interrupt handler.
111	 *
112	 * vecnum is where we'll put this code.
113	 * c_routine is the C routine we'll call.
114	 *
115	 * The C routine is passed two arguments:
116	 * - A pointer to the pt_regs state.
117	 * - The interrupt vector number.
118	 *
119	 * The "processing" argument specifies the code for processing
120	 * the interrupt. Defaults to "handle_interrupt".
121	 */
122	.macro  int_hand vecnum, vecname, c_routine, processing=handle_interrupt
123	.org    (\vecnum << 8)
124intvec_\vecname:
125	.ifc    \vecnum, INT_SWINT_1
126	blz     TREG_SYSCALL_NR_NAME, sys_cmpxchg
127	.endif
128
129	/* Temporarily save a register so we have somewhere to work. */
130
131	mtspr   SPR_SYSTEM_SAVE_K_1, r0
132	mfspr   r0, SPR_EX_CONTEXT_K_1
133
134	/* The cmpxchg code clears sp to force us to reset it here on fault. */
135	{
136	 bz     sp, 2f
137	 andi   r0, r0, SPR_EX_CONTEXT_1_1__PL_MASK  /* mask off ICS */
138	}
139
140	.ifc    \vecnum, INT_DOUBLE_FAULT
141	/*
142	 * For double-faults from user-space, fall through to the normal
143	 * register save and stack setup path.  Otherwise, it's the
144	 * hypervisor giving us one last chance to dump diagnostics, and we
145	 * branch to the kernel_double_fault routine to do so.
146	 */
147	bz      r0, 1f
148	j       _kernel_double_fault
1491:
150	.else
151	/*
152	 * If we're coming from user-space, then set sp to the top of
153	 * the kernel stack.  Otherwise, assume sp is already valid.
154	 */
155	{
156	 bnz    r0, 0f
157	 move   r0, sp
158	}
159	.endif
160
161	.ifc    \c_routine, do_page_fault
162	/*
163	 * The page_fault handler may be downcalled directly by the
164	 * hypervisor even when Linux is running and has ICS set.
165	 *
166	 * In this case the contents of EX_CONTEXT_K_1 reflect the
167	 * previous fault and can't be relied on to choose whether or
168	 * not to reinitialize the stack pointer.  So we add a test
169	 * to see whether SYSTEM_SAVE_K_2 has the high bit set,
170	 * and if so we don't reinitialize sp, since we must be coming
171	 * from Linux.  (In fact the precise case is !(val & ~1),
172	 * but any Linux PC has to have the high bit set.)
173	 *
174	 * Note that the hypervisor *always* sets SYSTEM_SAVE_K_2 for
175	 * any path that turns into a downcall to one of our TLB handlers.
176	 */
177	mfspr   r0, SPR_SYSTEM_SAVE_K_2
178	{
179	 blz    r0, 0f    /* high bit in S_S_1_2 is for a PC to use */
180	 move   r0, sp
181	}
182	.endif
183
1842:
185	/*
186	 * SYSTEM_SAVE_K_0 holds the cpu number in the low bits, and
187	 * the current stack top in the higher bits.  So we recover
188	 * our stack top by just masking off the low bits, then
189	 * point sp at the top aligned address on the actual stack page.
190	 */
191	mfspr   r0, SPR_SYSTEM_SAVE_K_0
192	mm      r0, r0, zero, LOG2_THREAD_SIZE, 31
193
1940:
195	/*
196	 * Align the stack mod 64 so we can properly predict what
197	 * cache lines we need to write-hint to reduce memory fetch
198	 * latency as we enter the kernel.  The layout of memory is
199	 * as follows, with cache line 0 at the lowest VA, and cache
200	 * line 4 just below the r0 value this "andi" computes.
201	 * Note that we never write to cache line 4, and we skip
202	 * cache line 1 for syscalls.
203	 *
204	 *    cache line 4: ptregs padding (two words)
205	 *    cache line 3: r46...lr, pc, ex1, faultnum, orig_r0, flags, pad
206	 *    cache line 2: r30...r45
207	 *    cache line 1: r14...r29
208	 *    cache line 0: 2 x frame, r0..r13
209	 */
210	andi    r0, r0, -64
211
212	/*
213	 * Push the first four registers on the stack, so that we can set
214	 * them to vector-unique values before we jump to the common code.
215	 *
216	 * Registers are pushed on the stack as a struct pt_regs,
217	 * with the sp initially just above the struct, and when we're
218	 * done, sp points to the base of the struct, minus
219	 * C_ABI_SAVE_AREA_SIZE, so we can directly jal to C code.
220	 *
221	 * This routine saves just the first four registers, plus the
222	 * stack context so we can do proper backtracing right away,
223	 * and defers to handle_interrupt to save the rest.
224	 * The backtracer needs pc, ex1, lr, sp, r52, and faultnum.
225	 */
226	addli   r0, r0, PTREGS_OFFSET_LR - (PTREGS_SIZE + KSTK_PTREGS_GAP)
227	wh64    r0    /* cache line 3 */
228	{
229	 sw     r0, lr
230	 addli  r0, r0, PTREGS_OFFSET_SP - PTREGS_OFFSET_LR
231	}
232	{
233	 sw     r0, sp
234	 addli  sp, r0, PTREGS_OFFSET_REG(52) - PTREGS_OFFSET_SP
235	}
236	{
237	 sw     sp, r52
238	 addli  sp, sp, PTREGS_OFFSET_REG(1) - PTREGS_OFFSET_REG(52)
239	}
240	wh64    sp    /* cache line 0 */
241	{
242	 sw     sp, r1
243	 addli  sp, sp, PTREGS_OFFSET_REG(2) - PTREGS_OFFSET_REG(1)
244	}
245	{
246	 sw     sp, r2
247	 addli  sp, sp, PTREGS_OFFSET_REG(3) - PTREGS_OFFSET_REG(2)
248	}
249	{
250	 sw     sp, r3
251	 addli  sp, sp, PTREGS_OFFSET_PC - PTREGS_OFFSET_REG(3)
252	}
253	mfspr   r0, SPR_EX_CONTEXT_K_0
254	.ifc \processing,handle_syscall
255	/*
256	 * Bump the saved PC by one bundle so that when we return, we won't
257	 * execute the same swint instruction again.  We need to do this while
258	 * we're in the critical section.
259	 */
260	addi    r0, r0, 8
261	.endif
262	{
263	 sw     sp, r0
264	 addli  sp, sp, PTREGS_OFFSET_EX1 - PTREGS_OFFSET_PC
265	}
266	mfspr   r0, SPR_EX_CONTEXT_K_1
267	{
268	 sw     sp, r0
269	 addi   sp, sp, PTREGS_OFFSET_FAULTNUM - PTREGS_OFFSET_EX1
270	/*
271	 * Use r0 for syscalls so it's a temporary; use r1 for interrupts
272	 * so that it gets passed through unchanged to the handler routine.
273	 * Note that the .if conditional confusingly spans bundles.
274	 */
275	 .ifc \processing,handle_syscall
276	 movei  r0, \vecnum
277	}
278	{
279	 sw     sp, r0
280	 .else
281	 movei  r1, \vecnum
282	}
283	{
284	 sw     sp, r1
285	 .endif
286	 addli  sp, sp, PTREGS_OFFSET_REG(0) - PTREGS_OFFSET_FAULTNUM
287	}
288	mfspr   r0, SPR_SYSTEM_SAVE_K_1    /* Original r0 */
289	{
290	 sw     sp, r0
291	 addi   sp, sp, -PTREGS_OFFSET_REG(0) - 4
292	}
293	{
294	 sw     sp, zero        /* write zero into "Next SP" frame pointer */
295	 addi   sp, sp, -4      /* leave SP pointing at bottom of frame */
296	}
297	.ifc \processing,handle_syscall
298	j       handle_syscall
299	.else
300	/*
301	 * Capture per-interrupt SPR context to registers.
302	 * We overload the meaning of r3 on this path such that if its bit 31
303	 * is set, we have to mask all interrupts including NMIs before
304	 * clearing the interrupt critical section bit.
305	 * See discussion below at "finish_interrupt_save".
306	 */
307	.ifc \c_routine, do_page_fault
308	mfspr   r2, SPR_SYSTEM_SAVE_K_3   /* address of page fault */
309	mfspr   r3, SPR_SYSTEM_SAVE_K_2   /* info about page fault */
310	.else
311	.ifc \vecnum, INT_DOUBLE_FAULT
312	{
313	 mfspr  r2, SPR_SYSTEM_SAVE_K_2   /* double fault info from HV */
314	 movei  r3, 0
315	}
316	.else
317	.ifc \c_routine, do_trap
318	{
319	 mfspr  r2, GPV_REASON
320	 movei  r3, 0
321	}
322	.else
323	.ifc \c_routine, op_handle_perf_interrupt
324	{
325	 mfspr  r2, PERF_COUNT_STS
326	 movei  r3, -1   /* not used, but set for consistency */
327	}
328	.else
329#if CHIP_HAS_AUX_PERF_COUNTERS()
330	.ifc \c_routine, op_handle_aux_perf_interrupt
331	{
332	 mfspr  r2, AUX_PERF_COUNT_STS
333	 movei  r3, -1   /* not used, but set for consistency */
334	}
335	.else
336#endif
337	movei   r3, 0
338#if CHIP_HAS_AUX_PERF_COUNTERS()
339	.endif
340#endif
341	.endif
342	.endif
343	.endif
344	.endif
345	/* Put function pointer in r0 */
346	moveli  r0, lo16(\c_routine)
347	{
348	 auli   r0, r0, ha16(\c_routine)
349	 j       \processing
350	}
351	.endif
352	ENDPROC(intvec_\vecname)
353
354#ifdef __COLLECT_LINKER_FEEDBACK__
355	.pushsection .text.intvec_feedback,"ax"
356	.org    (\vecnum << 5)
357	FEEDBACK_ENTER_EXPLICIT(intvec_\vecname, .intrpt1, 1 << 8)
358	jrp     lr
359	.popsection
360#endif
361
362	.endm
363
364
365	/*
366	 * Save the rest of the registers that we didn't save in the actual
367	 * vector itself.  We can't use r0-r10 inclusive here.
368	 */
369	.macro  finish_interrupt_save, function
370
371	/* If it's a syscall, save a proper orig_r0, otherwise just zero. */
372	PTREGS_PTR(r52, PTREGS_OFFSET_ORIG_R0)
373	{
374	 .ifc \function,handle_syscall
375	 sw     r52, r0
376	 .else
377	 sw     r52, zero
378	 .endif
379	 PTREGS_PTR(r52, PTREGS_OFFSET_TP)
380	}
381
382	/*
383	 * For ordinary syscalls, we save neither caller- nor callee-
384	 * save registers, since the syscall invoker doesn't expect the
385	 * caller-saves to be saved, and the called kernel functions will
386	 * take care of saving the callee-saves for us.
387	 *
388	 * For interrupts we save just the caller-save registers.  Saving
389	 * them is required (since the "caller" can't save them).  Again,
390	 * the called kernel functions will restore the callee-save
391	 * registers for us appropriately.
392	 *
393	 * On return, we normally restore nothing special for syscalls,
394	 * and just the caller-save registers for interrupts.
395	 *
396	 * However, there are some important caveats to all this:
397	 *
398	 * - We always save a few callee-save registers to give us
399	 *   some scratchpad registers to carry across function calls.
400	 *
401	 * - fork/vfork/etc require us to save all the callee-save
402	 *   registers, which we do in PTREGS_SYSCALL_ALL_REGS, below.
403	 *
404	 * - We always save r0..r5 and r10 for syscalls, since we need
405	 *   to reload them a bit later for the actual kernel call, and
406	 *   since we might need them for -ERESTARTNOINTR, etc.
407	 *
408	 * - Before invoking a signal handler, we save the unsaved
409	 *   callee-save registers so they are visible to the
410	 *   signal handler or any ptracer.
411	 *
412	 * - If the unsaved callee-save registers are modified, we set
413	 *   a bit in pt_regs so we know to reload them from pt_regs
414	 *   and not just rely on the kernel function unwinding.
415	 *   (Done for ptrace register writes and SA_SIGINFO handler.)
416	 */
417	{
418	 sw     r52, tp
419	 PTREGS_PTR(r52, PTREGS_OFFSET_REG(33))
420	}
421	wh64    r52    /* cache line 2 */
422	push_reg r33, r52
423	push_reg r32, r52
424	push_reg r31, r52
425	.ifc \function,handle_syscall
426	push_reg r30, r52, PTREGS_OFFSET_SYSCALL - PTREGS_OFFSET_REG(30)
427	push_reg TREG_SYSCALL_NR_NAME, r52, \
428	  PTREGS_OFFSET_REG(5) - PTREGS_OFFSET_SYSCALL
429	.else
430
431	push_reg r30, r52, PTREGS_OFFSET_REG(29) - PTREGS_OFFSET_REG(30)
432	wh64    r52    /* cache line 1 */
433	push_reg r29, r52
434	push_reg r28, r52
435	push_reg r27, r52
436	push_reg r26, r52
437	push_reg r25, r52
438	push_reg r24, r52
439	push_reg r23, r52
440	push_reg r22, r52
441	push_reg r21, r52
442	push_reg r20, r52
443	push_reg r19, r52
444	push_reg r18, r52
445	push_reg r17, r52
446	push_reg r16, r52
447	push_reg r15, r52
448	push_reg r14, r52
449	push_reg r13, r52
450	push_reg r12, r52
451	push_reg r11, r52
452	push_reg r10, r52
453	push_reg r9, r52
454	push_reg r8, r52
455	push_reg r7, r52
456	push_reg r6, r52
457
458	.endif
459
460	push_reg r5, r52
461	sw      r52, r4
462
463	/* Load tp with our per-cpu offset. */
464#ifdef CONFIG_SMP
465	{
466	 mfspr  r20, SPR_SYSTEM_SAVE_K_0
467	 moveli r21, lo16(__per_cpu_offset)
468	}
469	{
470	 auli   r21, r21, ha16(__per_cpu_offset)
471	 mm     r20, r20, zero, 0, LOG2_THREAD_SIZE-1
472	}
473	s2a     r20, r20, r21
474	lw      tp, r20
475#else
476	move    tp, zero
477#endif
478
479	/*
480	 * If we will be returning to the kernel, we will need to
481	 * reset the interrupt masks to the state they had before.
482	 * Set DISABLE_IRQ in flags iff we came from PL1 with irqs disabled.
483	 * We load flags in r32 here so we can jump to .Lrestore_regs
484	 * directly after do_page_fault_ics() if necessary.
485	 */
486	mfspr   r32, SPR_EX_CONTEXT_K_1
487	{
488	 andi   r32, r32, SPR_EX_CONTEXT_1_1__PL_MASK  /* mask off ICS */
489	 PTREGS_PTR(r21, PTREGS_OFFSET_FLAGS)
490	}
491	bzt     r32, 1f       /* zero if from user space */
492	IRQS_DISABLED(r32)    /* zero if irqs enabled */
493#if PT_FLAGS_DISABLE_IRQ != 1
494# error Value of IRQS_DISABLED used to set PT_FLAGS_DISABLE_IRQ; fix
495#endif
4961:
497	.ifnc \function,handle_syscall
498	/* Record the fact that we saved the caller-save registers above. */
499	ori     r32, r32, PT_FLAGS_CALLER_SAVES
500	.endif
501	sw      r21, r32
502
503#ifdef __COLLECT_LINKER_FEEDBACK__
504	/*
505	 * Notify the feedback routines that we were in the
506	 * appropriate fixed interrupt vector area.  Note that we
507	 * still have ICS set at this point, so we can't invoke any
508	 * atomic operations or we will panic.  The feedback
509	 * routines internally preserve r0..r10 and r30 up.
510	 */
511	.ifnc \function,handle_syscall
512	shli    r20, r1, 5
513	.else
514	moveli  r20, INT_SWINT_1 << 5
515	.endif
516	addli   r20, r20, lo16(intvec_feedback)
517	auli    r20, r20, ha16(intvec_feedback)
518	jalr    r20
519
520	/* And now notify the feedback routines that we are here. */
521	FEEDBACK_ENTER(\function)
522#endif
523
524	/*
525	 * we've captured enough state to the stack (including in
526	 * particular our EX_CONTEXT state) that we can now release
527	 * the interrupt critical section and replace it with our
528	 * standard "interrupts disabled" mask value.  This allows
529	 * synchronous interrupts (and profile interrupts) to punch
530	 * through from this point onwards.
531	 *
532	 * If bit 31 of r3 is set during a non-NMI interrupt, we know we
533	 * are on the path where the hypervisor has punched through our
534	 * ICS with a page fault, so we call out to do_page_fault_ics()
535	 * to figure out what to do with it.  If the fault was in
536	 * an atomic op, we unlock the atomic lock, adjust the
537	 * saved register state a little, and return "zero" in r4,
538	 * falling through into the normal page-fault interrupt code.
539	 * If the fault was in a kernel-space atomic operation, then
540	 * do_page_fault_ics() resolves it itself, returns "one" in r4,
541	 * and as a result goes directly to restoring registers and iret,
542	 * without trying to adjust the interrupt masks at all.
543	 * The do_page_fault_ics() API involves passing and returning
544	 * a five-word struct (in registers) to avoid writing the
545	 * save and restore code here.
546	 */
547	.ifc \function,handle_nmi
548	IRQ_DISABLE_ALL(r20)
549	.else
550	.ifnc \function,handle_syscall
551	bgezt   r3, 1f
552	{
553	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
554	 jal    do_page_fault_ics
555	}
556	FEEDBACK_REENTER(\function)
557	bzt     r4, 1f
558	j       .Lrestore_regs
5591:
560	.endif
561	IRQ_DISABLE(r20, r21)
562	.endif
563	mtspr   INTERRUPT_CRITICAL_SECTION, zero
564
565#if CHIP_HAS_WH64()
566	/*
567	 * Prepare the first 256 stack bytes to be rapidly accessible
568	 * without having to fetch the background data.  We don't really
569	 * know how far to write-hint, but kernel stacks generally
570	 * aren't that big, and write-hinting here does take some time.
571	 */
572	addi    r52, sp, -64
573	{
574	 wh64   r52
575	 addi   r52, r52, -64
576	}
577	{
578	 wh64   r52
579	 addi   r52, r52, -64
580	}
581	{
582	 wh64   r52
583	 addi   r52, r52, -64
584	}
585	wh64    r52
586#endif
587
588#ifdef CONFIG_TRACE_IRQFLAGS
589	.ifnc \function,handle_nmi
590	/*
591	 * We finally have enough state set up to notify the irq
592	 * tracing code that irqs were disabled on entry to the handler.
593	 * The TRACE_IRQS_OFF call clobbers registers r0-r29.
594	 * For syscalls, we already have the register state saved away
595	 * on the stack, so we don't bother to do any register saves here,
596	 * and later we pop the registers back off the kernel stack.
597	 * For interrupt handlers, save r0-r3 in callee-saved registers.
598	 */
599	.ifnc \function,handle_syscall
600	{ move r30, r0; move r31, r1 }
601	{ move r32, r2; move r33, r3 }
602	.endif
603	TRACE_IRQS_OFF
604	.ifnc \function,handle_syscall
605	{ move r0, r30; move r1, r31 }
606	{ move r2, r32; move r3, r33 }
607	.endif
608	.endif
609#endif
610
611	.endm
612
613	.macro  check_single_stepping, kind, not_single_stepping
614	/*
615	 * Check for single stepping in user-level priv
616	 *   kind can be "normal", "ill", or "syscall"
617	 * At end, if fall-thru
618	 *   r29: thread_info->step_state
619	 *   r28: &pt_regs->pc
620	 *   r27: pt_regs->pc
621	 *   r26: thread_info->step_state->buffer
622	 */
623
624	/* Check for single stepping */
625	GET_THREAD_INFO(r29)
626	{
627	 /* Get pointer to field holding step state */
628	 addi   r29, r29, THREAD_INFO_STEP_STATE_OFFSET
629
630	 /* Get pointer to EX1 in register state */
631	 PTREGS_PTR(r27, PTREGS_OFFSET_EX1)
632	}
633	{
634	 /* Get pointer to field holding PC */
635	 PTREGS_PTR(r28, PTREGS_OFFSET_PC)
636
637	 /* Load the pointer to the step state */
638	 lw     r29, r29
639	}
640	/* Load EX1 */
641	lw      r27, r27
642	{
643	 /* Points to flags */
644	 addi   r23, r29, SINGLESTEP_STATE_FLAGS_OFFSET
645
646	 /* No single stepping if there is no step state structure */
647	 bzt    r29, \not_single_stepping
648	}
649	{
650	 /* mask off ICS and any other high bits */
651	 andi   r27, r27, SPR_EX_CONTEXT_1_1__PL_MASK
652
653	 /* Load pointer to single step instruction buffer */
654	 lw     r26, r29
655	}
656	/* Check priv state */
657	bnz     r27, \not_single_stepping
658
659	/* Get flags */
660	lw      r22, r23
661	{
662	 /* Branch if single-step mode not enabled */
663	 bbnst  r22, \not_single_stepping
664
665	 /* Clear enabled flag */
666	 andi   r22, r22, ~SINGLESTEP_STATE_MASK_IS_ENABLED
667	}
668	.ifc \kind,normal
669	{
670	 /* Load PC */
671	 lw     r27, r28
672
673	 /* Point to the entry containing the original PC */
674	 addi   r24, r29, SINGLESTEP_STATE_ORIG_PC_OFFSET
675	}
676	{
677	 /* Disable single stepping flag */
678	 sw     r23, r22
679	}
680	{
681	 /* Get the original pc */
682	 lw     r24, r24
683
684	 /* See if the PC is at the start of the single step buffer */
685	 seq    r25, r26, r27
686	}
687	/*
688	 * NOTE: it is really expected that the PC be in the single step buffer
689	 *       at this point
690	 */
691	bzt     r25, \not_single_stepping
692
693	/* Restore the original PC */
694	sw      r28, r24
695	.else
696	.ifc \kind,syscall
697	{
698	 /* Load PC */
699	 lw     r27, r28
700
701	 /* Point to the entry containing the next PC */
702	 addi   r24, r29, SINGLESTEP_STATE_NEXT_PC_OFFSET
703	}
704	{
705	 /* Increment the stopped PC by the bundle size */
706	 addi   r26, r26, 8
707
708	 /* Disable single stepping flag */
709	 sw     r23, r22
710	}
711	{
712	 /* Get the next pc */
713	 lw     r24, r24
714
715	 /*
716	  * See if the PC is one bundle past the start of the
717	  * single step buffer
718	  */
719	 seq    r25, r26, r27
720	}
721	{
722	 /*
723	  * NOTE: it is really expected that the PC be in the
724	  * single step buffer at this point
725	  */
726	 bzt    r25, \not_single_stepping
727	}
728	/* Set to the next PC */
729	sw      r28, r24
730	.else
731	{
732	 /* Point to 3rd bundle in buffer */
733	 addi   r25, r26, 16
734
735	 /* Load PC */
736	 lw      r27, r28
737	}
738	{
739	 /* Disable single stepping flag */
740	 sw      r23, r22
741
742	 /* See if the PC is in the single step buffer */
743	 slte_u  r24, r26, r27
744	}
745	{
746	 slte_u r25, r27, r25
747
748	 /*
749	  * NOTE: it is really expected that the PC be in the
750	  * single step buffer at this point
751	  */
752	 bzt    r24, \not_single_stepping
753	}
754	bzt     r25, \not_single_stepping
755	.endif
756	.endif
757	.endm
758
759	/*
760	 * Redispatch a downcall.
761	 */
762	.macro  dc_dispatch vecnum, vecname
763	.org    (\vecnum << 8)
764intvec_\vecname:
765	j       hv_downcall_dispatch
766	ENDPROC(intvec_\vecname)
767	.endm
768
769	/*
770	 * Common code for most interrupts.  The C function we're eventually
771	 * going to is in r0, and the faultnum is in r1; the original
772	 * values for those registers are on the stack.
773	 */
774	.pushsection .text.handle_interrupt,"ax"
775handle_interrupt:
776	finish_interrupt_save handle_interrupt
777
778	/*
779	 * Check for if we are single stepping in user level. If so, then
780	 * we need to restore the PC.
781	 */
782
783	check_single_stepping normal, .Ldispatch_interrupt
784.Ldispatch_interrupt:
785
786	/* Jump to the C routine; it should enable irqs as soon as possible. */
787	{
788	 jalr   r0
789	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
790	}
791	FEEDBACK_REENTER(handle_interrupt)
792	{
793	 movei  r30, 0   /* not an NMI */
794	 j      interrupt_return
795	}
796	STD_ENDPROC(handle_interrupt)
797
798/*
799 * This routine takes a boolean in r30 indicating if this is an NMI.
800 * If so, we also expect a boolean in r31 indicating whether to
801 * re-enable the oprofile interrupts.
802 */
803STD_ENTRY(interrupt_return)
804	/* If we're resuming to kernel space, don't check thread flags. */
805	{
806	 bnz    r30, .Lrestore_all  /* NMIs don't special-case user-space */
807	 PTREGS_PTR(r29, PTREGS_OFFSET_EX1)
808	}
809	lw      r29, r29
810	andi    r29, r29, SPR_EX_CONTEXT_1_1__PL_MASK  /* mask off ICS */
811	{
812	 bzt    r29, .Lresume_userspace
813	 PTREGS_PTR(r29, PTREGS_OFFSET_PC)
814	}
815
816	/* If we're resuming to _cpu_idle_nap, bump PC forward by 8. */
817	{
818	 lw     r28, r29
819	 moveli r27, lo16(_cpu_idle_nap)
820	}
821	{
822	 auli   r27, r27, ha16(_cpu_idle_nap)
823	}
824	{
825	 seq    r27, r27, r28
826	}
827	{
828	 bbns   r27, .Lrestore_all
829	 addi   r28, r28, 8
830	}
831	sw      r29, r28
832	j       .Lrestore_all
833
834.Lresume_userspace:
835	FEEDBACK_REENTER(interrupt_return)
836
837	/*
838	 * Disable interrupts so as to make sure we don't
839	 * miss an interrupt that sets any of the thread flags (like
840	 * need_resched or sigpending) between sampling and the iret.
841	 * Routines like schedule() or do_signal() may re-enable
842	 * interrupts before returning.
843	 */
844	IRQ_DISABLE(r20, r21)
845	TRACE_IRQS_OFF  /* Note: clobbers registers r0-r29 */
846
847	/* Get base of stack in r32; note r30/31 are used as arguments here. */
848	GET_THREAD_INFO(r32)
849
850
851	/* Check to see if there is any work to do before returning to user. */
852	{
853	 addi   r29, r32, THREAD_INFO_FLAGS_OFFSET
854	 moveli r28, lo16(_TIF_ALLWORK_MASK)
855	}
856	{
857	 lw     r29, r29
858	 auli   r28, r28, ha16(_TIF_ALLWORK_MASK)
859	}
860	and     r28, r29, r28
861	bnz     r28, .Lwork_pending
862
863	/*
864	 * In the NMI case we
865	 * omit the call to single_process_check_nohz, which normally checks
866	 * to see if we should start or stop the scheduler tick, because
867	 * we can't call arbitrary Linux code from an NMI context.
868	 * We always call the homecache TLB deferral code to re-trigger
869	 * the deferral mechanism.
870	 *
871	 * The other chunk of responsibility this code has is to reset the
872	 * interrupt masks appropriately to reset irqs and NMIs.  We have
873	 * to call TRACE_IRQS_OFF and TRACE_IRQS_ON to support all the
874	 * lockdep-type stuff, but we can't set ICS until afterwards, since
875	 * ICS can only be used in very tight chunks of code to avoid
876	 * tripping over various assertions that it is off.
877	 *
878	 * (There is what looks like a window of vulnerability here since
879	 * we might take a profile interrupt between the two SPR writes
880	 * that set the mask, but since we write the low SPR word first,
881	 * and our interrupt entry code checks the low SPR word, any
882	 * profile interrupt will actually disable interrupts in both SPRs
883	 * before returning, which is OK.)
884	 */
885.Lrestore_all:
886	PTREGS_PTR(r0, PTREGS_OFFSET_EX1)
887	{
888	 lw     r0, r0
889	 PTREGS_PTR(r32, PTREGS_OFFSET_FLAGS)
890	}
891	{
892	 andi   r0, r0, SPR_EX_CONTEXT_1_1__PL_MASK
893	 lw     r32, r32
894	}
895	bnz    r0, 1f
896	j       2f
897#if PT_FLAGS_DISABLE_IRQ != 1
898# error Assuming PT_FLAGS_DISABLE_IRQ == 1 so we can use bbnst below
899#endif
9001:	bbnst   r32, 2f
901	IRQ_DISABLE(r20,r21)
902	TRACE_IRQS_OFF
903	movei   r0, 1
904	mtspr   INTERRUPT_CRITICAL_SECTION, r0
905	bzt     r30, .Lrestore_regs
906	j       3f
9072:	TRACE_IRQS_ON
908	movei   r0, 1
909	mtspr   INTERRUPT_CRITICAL_SECTION, r0
910	IRQ_ENABLE(r20, r21)
911	bzt     r30, .Lrestore_regs
9123:
913
914
915	/*
916	 * We now commit to returning from this interrupt, since we will be
917	 * doing things like setting EX_CONTEXT SPRs and unwinding the stack
918	 * frame.  No calls should be made to any other code after this point.
919	 * This code should only be entered with ICS set.
920	 * r32 must still be set to ptregs.flags.
921	 * We launch loads to each cache line separately first, so we can
922	 * get some parallelism out of the memory subsystem.
923	 * We start zeroing caller-saved registers throughout, since
924	 * that will save some cycles if this turns out to be a syscall.
925	 */
926.Lrestore_regs:
927	FEEDBACK_REENTER(interrupt_return)   /* called from elsewhere */
928
929	/*
930	 * Rotate so we have one high bit and one low bit to test.
931	 * - low bit says whether to restore all the callee-saved registers,
932	 *   or just r30-r33, and r52 up.
933	 * - high bit (i.e. sign bit) says whether to restore all the
934	 *   caller-saved registers, or just r0.
935	 */
936#if PT_FLAGS_CALLER_SAVES != 2 || PT_FLAGS_RESTORE_REGS != 4
937# error Rotate trick does not work :-)
938#endif
939	{
940	 rli    r20, r32, 30
941	 PTREGS_PTR(sp, PTREGS_OFFSET_REG(0))
942	}
943
944	/*
945	 * Load cache lines 0, 2, and 3 in that order, then use
946	 * the last loaded value, which makes it likely that the other
947	 * cache lines have also loaded, at which point we should be
948	 * able to safely read all the remaining words on those cache
949	 * lines without waiting for the memory subsystem.
950	 */
951	pop_reg_zero r0, r28, sp, PTREGS_OFFSET_REG(30) - PTREGS_OFFSET_REG(0)
952	pop_reg_zero r30, r2, sp, PTREGS_OFFSET_PC - PTREGS_OFFSET_REG(30)
953	pop_reg_zero r21, r3, sp, PTREGS_OFFSET_EX1 - PTREGS_OFFSET_PC
954	pop_reg_zero lr, r4, sp, PTREGS_OFFSET_REG(52) - PTREGS_OFFSET_EX1
955	{
956	 mtspr  SPR_EX_CONTEXT_K_0, r21
957	 move   r5, zero
958	}
959	{
960	 mtspr  SPR_EX_CONTEXT_K_1, lr
961	 andi   lr, lr, SPR_EX_CONTEXT_1_1__PL_MASK  /* mask off ICS */
962	}
963
964	/* Restore callee-saveds that we actually use. */
965	pop_reg_zero r52, r6, sp, PTREGS_OFFSET_REG(31) - PTREGS_OFFSET_REG(52)
966	pop_reg_zero r31, r7
967	pop_reg_zero r32, r8
968	pop_reg_zero r33, r9, sp, PTREGS_OFFSET_REG(29) - PTREGS_OFFSET_REG(33)
969
970	/*
971	 * If we modified other callee-saveds, restore them now.
972	 * This is rare, but could be via ptrace or signal handler.
973	 */
974	{
975	 move   r10, zero
976	 bbs    r20, .Lrestore_callees
977	}
978.Lcontinue_restore_regs:
979
980	/* Check if we're returning from a syscall. */
981	{
982	 move   r11, zero
983	 blzt   r20, 1f  /* no, so go restore callee-save registers */
984	}
985
986	/*
987	 * Check if we're returning to userspace.
988	 * Note that if we're not, we don't worry about zeroing everything.
989	 */
990	{
991	 addli  sp, sp, PTREGS_OFFSET_LR - PTREGS_OFFSET_REG(29)
992	 bnz    lr, .Lkernel_return
993	}
994
995	/*
996	 * On return from syscall, we've restored r0 from pt_regs, but we
997	 * clear the remainder of the caller-saved registers.  We could
998	 * restore the syscall arguments, but there's not much point,
999	 * and it ensures user programs aren't trying to use the
1000	 * caller-saves if we clear them, as well as avoiding leaking
1001	 * kernel pointers into userspace.
1002	 */
1003	pop_reg_zero lr, r12, sp, PTREGS_OFFSET_TP - PTREGS_OFFSET_LR
1004	pop_reg_zero tp, r13, sp, PTREGS_OFFSET_SP - PTREGS_OFFSET_TP
1005	{
1006	 lw     sp, sp
1007	 move   r14, zero
1008	 move   r15, zero
1009	}
1010	{ move r16, zero; move r17, zero }
1011	{ move r18, zero; move r19, zero }
1012	{ move r20, zero; move r21, zero }
1013	{ move r22, zero; move r23, zero }
1014	{ move r24, zero; move r25, zero }
1015	{ move r26, zero; move r27, zero }
1016
1017	/* Set r1 to errno if we are returning an error, otherwise zero. */
1018	{
1019	 moveli r29, 4096
1020	 sub    r1, zero, r0
1021	}
1022	slt_u   r29, r1, r29
1023	{
1024	 mnz    r1, r29, r1
1025	 move   r29, zero
1026	}
1027	iret
1028
1029	/*
1030	 * Not a syscall, so restore caller-saved registers.
1031	 * First kick off a load for cache line 1, which we're touching
1032	 * for the first time here.
1033	 */
1034	.align 64
10351:	pop_reg r29, sp, PTREGS_OFFSET_REG(1) - PTREGS_OFFSET_REG(29)
1036	pop_reg r1
1037	pop_reg r2
1038	pop_reg r3
1039	pop_reg r4
1040	pop_reg r5
1041	pop_reg r6
1042	pop_reg r7
1043	pop_reg r8
1044	pop_reg r9
1045	pop_reg r10
1046	pop_reg r11
1047	pop_reg r12
1048	pop_reg r13
1049	pop_reg r14
1050	pop_reg r15
1051	pop_reg r16
1052	pop_reg r17
1053	pop_reg r18
1054	pop_reg r19
1055	pop_reg r20
1056	pop_reg r21
1057	pop_reg r22
1058	pop_reg r23
1059	pop_reg r24
1060	pop_reg r25
1061	pop_reg r26
1062	pop_reg r27
1063	pop_reg r28, sp, PTREGS_OFFSET_LR - PTREGS_OFFSET_REG(28)
1064	/* r29 already restored above */
1065	bnz     lr, .Lkernel_return
1066	pop_reg lr, sp, PTREGS_OFFSET_TP - PTREGS_OFFSET_LR
1067	pop_reg tp, sp, PTREGS_OFFSET_SP - PTREGS_OFFSET_TP
1068	lw      sp, sp
1069	iret
1070
1071	/*
1072	 * We can't restore tp when in kernel mode, since a thread might
1073	 * have migrated from another cpu and brought a stale tp value.
1074	 */
1075.Lkernel_return:
1076	pop_reg lr, sp, PTREGS_OFFSET_SP - PTREGS_OFFSET_LR
1077	lw      sp, sp
1078	iret
1079
1080	/* Restore callee-saved registers from r34 to r51. */
1081.Lrestore_callees:
1082	addli  sp, sp, PTREGS_OFFSET_REG(34) - PTREGS_OFFSET_REG(29)
1083	pop_reg r34
1084	pop_reg r35
1085	pop_reg r36
1086	pop_reg r37
1087	pop_reg r38
1088	pop_reg r39
1089	pop_reg r40
1090	pop_reg r41
1091	pop_reg r42
1092	pop_reg r43
1093	pop_reg r44
1094	pop_reg r45
1095	pop_reg r46
1096	pop_reg r47
1097	pop_reg r48
1098	pop_reg r49
1099	pop_reg r50
1100	pop_reg r51, sp, PTREGS_OFFSET_REG(29) - PTREGS_OFFSET_REG(51)
1101	j .Lcontinue_restore_regs
1102
1103.Lwork_pending:
1104	/* Mask the reschedule flag */
1105	andi    r28, r29, _TIF_NEED_RESCHED
1106
1107	{
1108	 /*
1109	  * If the NEED_RESCHED flag is called, we call schedule(), which
1110	  * may drop this context right here and go do something else.
1111	  * On return, jump back to .Lresume_userspace and recheck.
1112	  */
1113	 bz     r28, .Lasync_tlb
1114
1115	 /* Mask the async-tlb flag */
1116	 andi   r28, r29, _TIF_ASYNC_TLB
1117	}
1118
1119	jal     schedule
1120	FEEDBACK_REENTER(interrupt_return)
1121
1122	/* Reload the flags and check again */
1123	j       .Lresume_userspace
1124
1125.Lasync_tlb:
1126	{
1127	 bz     r28, .Lneed_sigpending
1128
1129	 /* Mask the sigpending flag */
1130	 andi   r28, r29, _TIF_SIGPENDING
1131	}
1132
1133	PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
1134	jal     do_async_page_fault
1135	FEEDBACK_REENTER(interrupt_return)
1136
1137	/*
1138	 * Go restart the "resume userspace" process.  We may have
1139	 * fired a signal, and we need to disable interrupts again.
1140	 */
1141	j       .Lresume_userspace
1142
1143.Lneed_sigpending:
1144	/*
1145	 * At this point we are either doing signal handling or single-step,
1146	 * so either way make sure we have all the registers saved.
1147	 */
1148	push_extra_callee_saves r0
1149
1150	{
1151	 /* If no signal pending, skip to singlestep check */
1152	 bz     r28, .Lneed_singlestep
1153
1154	 /* Mask the singlestep flag */
1155	 andi   r28, r29, _TIF_SINGLESTEP
1156	}
1157
1158	jal     do_signal
1159	FEEDBACK_REENTER(interrupt_return)
1160
1161	/* Reload the flags and check again */
1162	j       .Lresume_userspace
1163
1164.Lneed_singlestep:
1165	{
1166	 /* Get a pointer to the EX1 field */
1167	 PTREGS_PTR(r29, PTREGS_OFFSET_EX1)
1168
1169	 /* If we get here, our bit must be set. */
1170	 bz     r28, .Lwork_confusion
1171	}
1172	/* If we are in priv mode, don't single step */
1173	lw      r28, r29
1174	andi    r28, r28, SPR_EX_CONTEXT_1_1__PL_MASK  /* mask off ICS */
1175	bnz     r28, .Lrestore_all
1176
1177	/* Allow interrupts within the single step code */
1178	TRACE_IRQS_ON  /* Note: clobbers registers r0-r29 */
1179	IRQ_ENABLE(r20, r21)
1180
1181	/* try to single-step the current instruction */
1182	PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
1183	jal     single_step_once
1184	FEEDBACK_REENTER(interrupt_return)
1185
1186	/* Re-disable interrupts.  TRACE_IRQS_OFF in .Lrestore_all. */
1187	IRQ_DISABLE(r20,r21)
1188
1189	j       .Lrestore_all
1190
1191.Lwork_confusion:
1192	move    r0, r28
1193	panic   "thread_info allwork flags unhandled on userspace resume: %#x"
1194
1195	STD_ENDPROC(interrupt_return)
1196
1197	/*
1198	 * Some interrupts don't check for single stepping
1199	 */
1200	.pushsection .text.handle_interrupt_no_single_step,"ax"
1201handle_interrupt_no_single_step:
1202	finish_interrupt_save handle_interrupt_no_single_step
1203	{
1204	 jalr   r0
1205	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
1206	}
1207	FEEDBACK_REENTER(handle_interrupt_no_single_step)
1208	{
1209	 movei  r30, 0   /* not an NMI */
1210	 j      interrupt_return
1211	}
1212	STD_ENDPROC(handle_interrupt_no_single_step)
1213
1214	/*
1215	 * "NMI" interrupts mask ALL interrupts before calling the
1216	 * handler, and don't check thread flags, etc., on the way
1217	 * back out.  In general, the only things we do here for NMIs
1218	 * are the register save/restore, fixing the PC if we were
1219	 * doing single step, and the dataplane kernel-TLB management.
1220	 * We don't (for example) deal with start/stop of the sched tick.
1221	 */
1222	.pushsection .text.handle_nmi,"ax"
1223handle_nmi:
1224	finish_interrupt_save handle_nmi
1225	check_single_stepping normal, .Ldispatch_nmi
1226.Ldispatch_nmi:
1227	{
1228	 jalr   r0
1229	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
1230	}
1231	FEEDBACK_REENTER(handle_nmi)
1232	j       interrupt_return
1233	STD_ENDPROC(handle_nmi)
1234
1235	/*
1236	 * Parallel code for syscalls to handle_interrupt.
1237	 */
1238	.pushsection .text.handle_syscall,"ax"
1239handle_syscall:
1240	finish_interrupt_save handle_syscall
1241
1242	/*
1243	 * Check for if we are single stepping in user level. If so, then
1244	 * we need to restore the PC.
1245	 */
1246	check_single_stepping syscall, .Ldispatch_syscall
1247.Ldispatch_syscall:
1248
1249	/* Enable irqs. */
1250	TRACE_IRQS_ON
1251	IRQ_ENABLE(r20, r21)
1252
1253	/* Bump the counter for syscalls made on this tile. */
1254	moveli  r20, lo16(irq_stat + IRQ_CPUSTAT_SYSCALL_COUNT_OFFSET)
1255	auli    r20, r20, ha16(irq_stat + IRQ_CPUSTAT_SYSCALL_COUNT_OFFSET)
1256	add     r20, r20, tp
1257	lw      r21, r20
1258	addi    r21, r21, 1
1259	sw      r20, r21
1260
1261	/* Trace syscalls, if requested. */
1262	GET_THREAD_INFO(r31)
1263	addi	r31, r31, THREAD_INFO_FLAGS_OFFSET
1264	lw	r30, r31
1265	andi    r30, r30, _TIF_SYSCALL_TRACE
1266	bzt	r30, .Lrestore_syscall_regs
1267	jal	do_syscall_trace
1268	FEEDBACK_REENTER(handle_syscall)
1269
1270	/*
1271	 * We always reload our registers from the stack at this
1272	 * point.  They might be valid, if we didn't build with
1273	 * TRACE_IRQFLAGS, and this isn't a dataplane tile, and we're not
1274	 * doing syscall tracing, but there are enough cases now that it
1275	 * seems simplest just to do the reload unconditionally.
1276	 */
1277.Lrestore_syscall_regs:
1278	PTREGS_PTR(r11, PTREGS_OFFSET_REG(0))
1279	pop_reg r0, r11
1280	pop_reg r1, r11
1281	pop_reg r2, r11
1282	pop_reg r3, r11
1283	pop_reg r4, r11
1284	pop_reg r5, r11, PTREGS_OFFSET_SYSCALL - PTREGS_OFFSET_REG(5)
1285	pop_reg TREG_SYSCALL_NR_NAME, r11
1286
1287	/* Ensure that the syscall number is within the legal range. */
1288	moveli  r21, __NR_syscalls
1289	{
1290	 slt_u  r21, TREG_SYSCALL_NR_NAME, r21
1291	 moveli r20, lo16(sys_call_table)
1292	}
1293	{
1294	 bbns   r21, .Linvalid_syscall
1295	 auli   r20, r20, ha16(sys_call_table)
1296	}
1297	s2a     r20, TREG_SYSCALL_NR_NAME, r20
1298	lw      r20, r20
1299
1300	/* Jump to syscall handler. */
1301	jalr    r20
1302.Lhandle_syscall_link: /* value of "lr" after "jalr r20" above */
1303
1304	/*
1305	 * Write our r0 onto the stack so it gets restored instead
1306	 * of whatever the user had there before.
1307	 */
1308	PTREGS_PTR(r29, PTREGS_OFFSET_REG(0))
1309	sw      r29, r0
1310
1311.Lsyscall_sigreturn_skip:
1312	FEEDBACK_REENTER(handle_syscall)
1313
1314	/* Do syscall trace again, if requested. */
1315	lw	r30, r31
1316	andi    r30, r30, _TIF_SYSCALL_TRACE
1317	bzt     r30, 1f
1318	jal	do_syscall_trace
1319	FEEDBACK_REENTER(handle_syscall)
13201:	j       .Lresume_userspace   /* jump into middle of interrupt_return */
1321
1322.Linvalid_syscall:
1323	/* Report an invalid syscall back to the user program */
1324	{
1325	 PTREGS_PTR(r29, PTREGS_OFFSET_REG(0))
1326	 movei  r28, -ENOSYS
1327	}
1328	sw      r29, r28
1329	j       .Lresume_userspace   /* jump into middle of interrupt_return */
1330	STD_ENDPROC(handle_syscall)
1331
1332	/* Return the address for oprofile to suppress in backtraces. */
1333STD_ENTRY_SECTION(handle_syscall_link_address, .text.handle_syscall)
1334	lnk     r0
1335	{
1336	 addli  r0, r0, .Lhandle_syscall_link - .
1337	 jrp    lr
1338	}
1339	STD_ENDPROC(handle_syscall_link_address)
1340
1341STD_ENTRY(ret_from_fork)
1342	jal     sim_notify_fork
1343	jal     schedule_tail
1344	FEEDBACK_REENTER(ret_from_fork)
1345	j       .Lresume_userspace   /* jump into middle of interrupt_return */
1346	STD_ENDPROC(ret_from_fork)
1347
1348	/*
1349	 * Code for ill interrupt.
1350	 */
1351	.pushsection .text.handle_ill,"ax"
1352handle_ill:
1353	finish_interrupt_save handle_ill
1354
1355	/*
1356	 * Check for if we are single stepping in user level. If so, then
1357	 * we need to restore the PC.
1358	 */
1359	check_single_stepping ill, .Ldispatch_normal_ill
1360
1361	{
1362	 /* See if the PC is the 1st bundle in the buffer */
1363	 seq    r25, r27, r26
1364
1365	 /* Point to the 2nd bundle in the buffer */
1366	 addi   r26, r26, 8
1367	}
1368	{
1369	 /* Point to the original pc */
1370	 addi   r24, r29, SINGLESTEP_STATE_ORIG_PC_OFFSET
1371
1372	 /* Branch if the PC is the 1st bundle in the buffer */
1373	 bnz    r25, 3f
1374	}
1375	{
1376	 /* See if the PC is the 2nd bundle of the buffer */
1377	 seq    r25, r27, r26
1378
1379	 /* Set PC to next instruction */
1380	 addi   r24, r29, SINGLESTEP_STATE_NEXT_PC_OFFSET
1381	}
1382	{
1383	 /* Point to flags */
1384	 addi   r25, r29, SINGLESTEP_STATE_FLAGS_OFFSET
1385
1386	 /* Branch if PC is in the second bundle */
1387	 bz     r25, 2f
1388	}
1389	/* Load flags */
1390	lw      r25, r25
1391	{
1392	 /*
1393	  * Get the offset for the register to restore
1394	  * Note: the lower bound is 2, so we have implicit scaling by 4.
1395	  *  No multiplication of the register number by the size of a register
1396	  *  is needed.
1397	  */
1398	 mm     r27, r25, zero, SINGLESTEP_STATE_TARGET_LB, \
1399		SINGLESTEP_STATE_TARGET_UB
1400
1401	 /* Mask Rewrite_LR */
1402	 andi   r25, r25, SINGLESTEP_STATE_MASK_UPDATE
1403	}
1404	{
1405	 addi   r29, r29, SINGLESTEP_STATE_UPDATE_VALUE_OFFSET
1406
1407	 /* Don't rewrite temp register */
1408	 bz     r25, 3f
1409	}
1410	{
1411	 /* Get the temp value */
1412	 lw     r29, r29
1413
1414	 /* Point to where the register is stored */
1415	 add    r27, r27, sp
1416	}
1417
1418	/* Add in the C ABI save area size to the register offset */
1419	addi    r27, r27, C_ABI_SAVE_AREA_SIZE
1420
1421	/* Restore the user's register with the temp value */
1422	sw      r27, r29
1423	j       3f
1424
14252:
1426	/* Must be in the third bundle */
1427	addi    r24, r29, SINGLESTEP_STATE_BRANCH_NEXT_PC_OFFSET
1428
14293:
1430	/* set PC and continue */
1431	lw      r26, r24
1432	sw      r28, r26
1433
1434	/*
1435	 * Clear TIF_SINGLESTEP to prevent recursion if we execute an ill.
1436	 * The normal non-arch flow redundantly clears TIF_SINGLESTEP, but we
1437	 * need to clear it here and can't really impose on all other arches.
1438	 * So what's another write between friends?
1439	 */
1440	GET_THREAD_INFO(r0)
1441
1442	addi    r1, r0, THREAD_INFO_FLAGS_OFFSET
1443	{
1444	 lw     r2, r1
1445	 addi   r0, r0, THREAD_INFO_TASK_OFFSET  /* currently a no-op */
1446	}
1447	andi    r2, r2, ~_TIF_SINGLESTEP
1448	sw      r1, r2
1449
1450	/* Issue a sigtrap */
1451	{
1452	 lw     r0, r0          /* indirect thru thread_info to get task_info*/
1453	 addi   r1, sp, C_ABI_SAVE_AREA_SIZE  /* put ptregs pointer into r1 */
1454	 move   r2, zero        /* load error code into r2 */
1455	}
1456
1457	jal     send_sigtrap    /* issue a SIGTRAP */
1458	FEEDBACK_REENTER(handle_ill)
1459	j       .Lresume_userspace   /* jump into middle of interrupt_return */
1460
1461.Ldispatch_normal_ill:
1462	{
1463	 jalr   r0
1464	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
1465	}
1466	FEEDBACK_REENTER(handle_ill)
1467	{
1468	 movei  r30, 0   /* not an NMI */
1469	 j      interrupt_return
1470	}
1471	STD_ENDPROC(handle_ill)
1472
1473/* Various stub interrupt handlers and syscall handlers */
1474
1475STD_ENTRY_LOCAL(_kernel_double_fault)
1476	mfspr   r1, SPR_EX_CONTEXT_K_0
1477	move    r2, lr
1478	move    r3, sp
1479	move    r4, r52
1480	addi    sp, sp, -C_ABI_SAVE_AREA_SIZE
1481	j       kernel_double_fault
1482	STD_ENDPROC(_kernel_double_fault)
1483
1484STD_ENTRY_LOCAL(bad_intr)
1485	mfspr   r2, SPR_EX_CONTEXT_K_0
1486	panic   "Unhandled interrupt %#x: PC %#lx"
1487	STD_ENDPROC(bad_intr)
1488
1489/* Put address of pt_regs in reg and jump. */
1490#define PTREGS_SYSCALL(x, reg)                          \
1491	STD_ENTRY(_##x);                                \
1492	{                                               \
1493	 PTREGS_PTR(reg, PTREGS_OFFSET_BASE);           \
1494	 j      x                                       \
1495	};                                              \
1496	STD_ENDPROC(_##x)
1497
1498/*
1499 * Special-case sigreturn to not write r0 to the stack on return.
1500 * This is technically more efficient, but it also avoids difficulties
1501 * in the 64-bit OS when handling 32-bit compat code, since we must not
1502 * sign-extend r0 for the sigreturn return-value case.
1503 */
1504#define PTREGS_SYSCALL_SIGRETURN(x, reg)                \
1505	STD_ENTRY(_##x);                                \
1506	addli   lr, lr, .Lsyscall_sigreturn_skip - .Lhandle_syscall_link; \
1507	{                                               \
1508	 PTREGS_PTR(reg, PTREGS_OFFSET_BASE);           \
1509	 j      x                                       \
1510	};                                              \
1511	STD_ENDPROC(_##x)
1512
1513PTREGS_SYSCALL(sys_execve, r3)
1514PTREGS_SYSCALL(sys_sigaltstack, r2)
1515PTREGS_SYSCALL_SIGRETURN(sys_rt_sigreturn, r0)
1516PTREGS_SYSCALL(sys_cmpxchg_badaddr, r1)
1517
1518/* Save additional callee-saves to pt_regs, put address in r4 and jump. */
1519STD_ENTRY(_sys_clone)
1520	push_extra_callee_saves r4
1521	j       sys_clone
1522	STD_ENDPROC(_sys_clone)
1523
1524/*
1525 * This entrypoint is taken for the cmpxchg and atomic_update fast
1526 * swints.  We may wish to generalize it to other fast swints at some
1527 * point, but for now there are just two very similar ones, which
1528 * makes it faster.
1529 *
1530 * The fast swint code is designed to have a small footprint.  It does
1531 * not save or restore any GPRs, counting on the caller-save registers
1532 * to be available to it on entry.  It does not modify any callee-save
1533 * registers (including "lr").  It does not check what PL it is being
1534 * called at, so you'd better not call it other than at PL0.
1535 * The <atomic.h> wrapper assumes it only clobbers r20-r29, so if
1536 * it ever is necessary to use more registers, be aware.
1537 *
1538 * It does not use the stack, but since it might be re-interrupted by
1539 * a page fault which would assume the stack was valid, it does
1540 * save/restore the stack pointer and zero it out to make sure it gets reset.
1541 * Since we always keep interrupts disabled, the hypervisor won't
1542 * clobber our EX_CONTEXT_K_x registers, so we don't save/restore them
1543 * (other than to advance the PC on return).
1544 *
1545 * We have to manually validate the user vs kernel address range
1546 * (since at PL1 we can read/write both), and for performance reasons
1547 * we don't allow cmpxchg on the fc000000 memory region, since we only
1548 * validate that the user address is below PAGE_OFFSET.
1549 *
1550 * We place it in the __HEAD section to ensure it is relatively
1551 * near to the intvec_SWINT_1 code (reachable by a conditional branch).
1552 *
1553 * Must match register usage in do_page_fault().
1554 */
1555	__HEAD
1556	.align 64
1557	/* Align much later jump on the start of a cache line. */
1558#if !ATOMIC_LOCKS_FOUND_VIA_TABLE()
1559	nop
1560#if PAGE_SIZE >= 0x10000
1561	nop
1562#endif
1563#endif
1564ENTRY(sys_cmpxchg)
1565
1566	/*
1567	 * Save "sp" and set it zero for any possible page fault.
1568	 *
1569	 * HACK: We want to both zero sp and check r0's alignment,
1570	 * so we do both at once. If "sp" becomes nonzero we
1571	 * know r0 is unaligned and branch to the error handler that
1572	 * restores sp, so this is OK.
1573	 *
1574	 * ICS is disabled right now so having a garbage but nonzero
1575	 * sp is OK, since we won't execute any faulting instructions
1576	 * when it is nonzero.
1577	 */
1578	{
1579	 move   r27, sp
1580	 andi	sp, r0, 3
1581	}
1582
1583	/*
1584	 * Get the lock address in ATOMIC_LOCK_REG, and also validate that the
1585	 * address is less than PAGE_OFFSET, since that won't trap at PL1.
1586	 * We only use bits less than PAGE_SHIFT to avoid having to worry
1587	 * about aliasing among multiple mappings of the same physical page,
1588	 * and we ignore the low 3 bits so we have one lock that covers
1589	 * both a cmpxchg64() and a cmpxchg() on either its low or high word.
1590	 * NOTE: this must match __atomic_hashed_lock() in lib/atomic_32.c.
1591	 */
1592
1593#if (PAGE_OFFSET & 0xffff) != 0
1594# error Code here assumes PAGE_OFFSET can be loaded with just hi16()
1595#endif
1596
1597#if ATOMIC_LOCKS_FOUND_VIA_TABLE()
1598	{
1599	 /* Check for unaligned input. */
1600	 bnz    sp, .Lcmpxchg_badaddr
1601	 mm     r25, r0, zero, 3, PAGE_SHIFT-1
1602	}
1603	{
1604	 crc32_32 r25, zero, r25
1605	 moveli r21, lo16(atomic_lock_ptr)
1606	}
1607	{
1608	 auli   r21, r21, ha16(atomic_lock_ptr)
1609	 auli   r23, zero, hi16(PAGE_OFFSET)  /* hugepage-aligned */
1610	}
1611	{
1612	 shri	r20, r25, 32 - ATOMIC_HASH_L1_SHIFT
1613	 slt_u  r23, r0, r23
1614
1615	 /*
1616	  * Ensure that the TLB is loaded before we take out the lock.
1617	  * On TILEPro, this will start fetching the value all the way
1618	  * into our L1 as well (and if it gets modified before we
1619	  * grab the lock, it will be invalidated from our cache
1620	  * before we reload it).  On tile64, we'll start fetching it
1621	  * into our L1 if we're the home, and if we're not, we'll
1622	  * still at least start fetching it into the home's L2.
1623	  */
1624	 lw	r26, r0
1625	}
1626	{
1627	 s2a    r21, r20, r21
1628	 bbns   r23, .Lcmpxchg_badaddr
1629	}
1630	{
1631	 lw     r21, r21
1632	 seqi	r23, TREG_SYSCALL_NR_NAME, __NR_FAST_cmpxchg64
1633	 andi	r25, r25, ATOMIC_HASH_L2_SIZE - 1
1634	}
1635	{
1636	 /* Branch away at this point if we're doing a 64-bit cmpxchg. */
1637	 bbs    r23, .Lcmpxchg64
1638	 andi   r23, r0, 7       /* Precompute alignment for cmpxchg64. */
1639	}
1640
1641	{
1642	 /*
1643	  * We very carefully align the code that actually runs with
1644	  * the lock held (nine bundles) so that we know it is all in
1645	  * the icache when we start.  This instruction (the jump) is
1646	  * at the start of the first cache line, address zero mod 64;
1647	  * we jump to somewhere in the second cache line to issue the
1648	  * tns, then jump back to finish up.
1649	  */
1650	 s2a	ATOMIC_LOCK_REG_NAME, r25, r21
1651	 j      .Lcmpxchg32_tns
1652	}
1653
1654#else /* ATOMIC_LOCKS_FOUND_VIA_TABLE() */
1655	{
1656	 /* Check for unaligned input. */
1657	 bnz    sp, .Lcmpxchg_badaddr
1658	 auli   r23, zero, hi16(PAGE_OFFSET)  /* hugepage-aligned */
1659	}
1660	{
1661	 /*
1662	  * Slide bits into position for 'mm'. We want to ignore
1663	  * the low 3 bits of r0, and consider only the next
1664	  * ATOMIC_HASH_SHIFT bits.
1665	  * Because of C pointer arithmetic, we want to compute this:
1666	  *
1667	  * ((char*)atomic_locks +
1668	  *  (((r0 >> 3) & (1 << (ATOMIC_HASH_SIZE - 1))) << 2))
1669	  *
1670	  * Instead of two shifts we just ">> 1", and use 'mm'
1671	  * to ignore the low and high bits we don't want.
1672	  */
1673	 shri	r25, r0, 1
1674
1675	 slt_u  r23, r0, r23
1676
1677	 /*
1678	  * Ensure that the TLB is loaded before we take out the lock.
1679	  * On tilepro, this will start fetching the value all the way
1680	  * into our L1 as well (and if it gets modified before we
1681	  * grab the lock, it will be invalidated from our cache
1682	  * before we reload it).  On tile64, we'll start fetching it
1683	  * into our L1 if we're the home, and if we're not, we'll
1684	  * still at least start fetching it into the home's L2.
1685	  */
1686	 lw	r26, r0
1687	}
1688	{
1689	 auli	r21, zero, ha16(atomic_locks)
1690
1691	 bbns   r23, .Lcmpxchg_badaddr
1692	}
1693#if PAGE_SIZE < 0x10000
1694	/* atomic_locks is page-aligned so for big pages we don't need this. */
1695	addli   r21, r21, lo16(atomic_locks)
1696#endif
1697	{
1698	 /*
1699	  * Insert the hash bits into the page-aligned pointer.
1700	  * ATOMIC_HASH_SHIFT is so big that we don't actually hash
1701	  * the unmasked address bits, as that may cause unnecessary
1702	  * collisions.
1703	  */
1704	 mm	ATOMIC_LOCK_REG_NAME, r25, r21, 2, (ATOMIC_HASH_SHIFT + 2) - 1
1705
1706	 seqi	r23, TREG_SYSCALL_NR_NAME, __NR_FAST_cmpxchg64
1707	}
1708	{
1709	 /* Branch away at this point if we're doing a 64-bit cmpxchg. */
1710	 bbs    r23, .Lcmpxchg64
1711	 andi   r23, r0, 7       /* Precompute alignment for cmpxchg64. */
1712	}
1713	{
1714	 /*
1715	  * We very carefully align the code that actually runs with
1716	  * the lock held (nine bundles) so that we know it is all in
1717	  * the icache when we start.  This instruction (the jump) is
1718	  * at the start of the first cache line, address zero mod 64;
1719	  * we jump to somewhere in the second cache line to issue the
1720	  * tns, then jump back to finish up.
1721	  */
1722	 j      .Lcmpxchg32_tns
1723	}
1724
1725#endif /* ATOMIC_LOCKS_FOUND_VIA_TABLE() */
1726
1727	ENTRY(__sys_cmpxchg_grab_lock)
1728
1729	/*
1730	 * Perform the actual cmpxchg or atomic_update.
1731	 * Note that the system <arch/atomic.h> header relies on
1732	 * atomic_update() to always perform an "mf", so don't make
1733	 * it optional or conditional without modifying that code.
1734	 */
1735.Ldo_cmpxchg32:
1736	{
1737	 lw     r21, r0
1738	 seqi	r23, TREG_SYSCALL_NR_NAME, __NR_FAST_atomic_update
1739	 move	r24, r2
1740	}
1741	{
1742	 seq    r22, r21, r1     /* See if cmpxchg matches. */
1743	 and	r25, r21, r1     /* If atomic_update, compute (*mem & mask) */
1744	}
1745	{
1746	 or	r22, r22, r23    /* Skip compare branch for atomic_update. */
1747	 add	r25, r25, r2     /* Compute (*mem & mask) + addend. */
1748	}
1749	{
1750	 mvnz	r24, r23, r25    /* Use atomic_update value if appropriate. */
1751	 bbns   r22, .Lcmpxchg32_mismatch
1752	}
1753	sw      r0, r24
1754
1755	/* Do slow mtspr here so the following "mf" waits less. */
1756	{
1757	 move   sp, r27
1758	 mtspr  SPR_EX_CONTEXT_K_0, r28
1759	}
1760	mf
1761
1762	/* The following instruction is the start of the second cache line. */
1763	{
1764	 move   r0, r21
1765	 sw     ATOMIC_LOCK_REG_NAME, zero
1766	}
1767	iret
1768
1769	/* Duplicated code here in the case where we don't overlap "mf" */
1770.Lcmpxchg32_mismatch:
1771	{
1772	 move   r0, r21
1773	 sw     ATOMIC_LOCK_REG_NAME, zero
1774	}
1775	{
1776	 move   sp, r27
1777	 mtspr  SPR_EX_CONTEXT_K_0, r28
1778	}
1779	iret
1780
1781	/*
1782	 * The locking code is the same for 32-bit cmpxchg/atomic_update,
1783	 * and for 64-bit cmpxchg.  We provide it as a macro and put
1784	 * it into both versions.  We can't share the code literally
1785	 * since it depends on having the right branch-back address.
1786	 * Note that the first few instructions should share the cache
1787	 * line with the second half of the actual locked code.
1788	 */
1789	.macro  cmpxchg_lock, bitwidth
1790
1791	/* Lock; if we succeed, jump back up to the read-modify-write. */
1792#ifdef CONFIG_SMP
1793	tns     r21, ATOMIC_LOCK_REG_NAME
1794#else
1795	/*
1796	 * Non-SMP preserves all the lock infrastructure, to keep the
1797	 * code simpler for the interesting (SMP) case.  However, we do
1798	 * one small optimization here and in atomic_asm.S, which is
1799	 * to fake out acquiring the actual lock in the atomic_lock table.
1800	 */
1801	movei	r21, 0
1802#endif
1803
1804	/* Issue the slow SPR here while the tns result is in flight. */
1805	mfspr   r28, SPR_EX_CONTEXT_K_0
1806
1807	{
1808	 addi   r28, r28, 8    /* return to the instruction after the swint1 */
1809	 bzt    r21, .Ldo_cmpxchg\bitwidth
1810	}
1811	/*
1812	 * The preceding instruction is the last thing that must be
1813	 * on the second cache line.
1814	 */
1815
1816#ifdef CONFIG_SMP
1817	/*
1818	 * We failed to acquire the tns lock on our first try.  Now use
1819	 * bounded exponential backoff to retry, like __atomic_spinlock().
1820	 */
1821	{
1822	 moveli r23, 2048       /* maximum backoff time in cycles */
1823	 moveli r25, 32         /* starting backoff time in cycles */
1824	}
18251:	mfspr   r26, CYCLE_LOW  /* get start point for this backoff */
18262:	mfspr   r22, CYCLE_LOW  /* test to see if we've backed off enough */
1827	sub     r22, r22, r26
1828	slt     r22, r22, r25
1829	bbst    r22, 2b
1830	{
1831	 shli   r25, r25, 1     /* double the backoff; retry the tns */
1832	 tns    r21, ATOMIC_LOCK_REG_NAME
1833	}
1834	slt     r26, r23, r25   /* is the proposed backoff too big? */
1835	{
1836	 mvnz   r25, r26, r23
1837	 bzt    r21, .Ldo_cmpxchg\bitwidth
1838	}
1839	j       1b
1840#endif /* CONFIG_SMP */
1841	.endm
1842
1843.Lcmpxchg32_tns:
1844	cmpxchg_lock 32
1845
1846	/*
1847	 * This code is invoked from sys_cmpxchg after most of the
1848	 * preconditions have been checked.  We still need to check
1849	 * that r0 is 8-byte aligned, since if it's not we won't
1850	 * actually be atomic.  However, ATOMIC_LOCK_REG has the atomic
1851	 * lock pointer and r27/r28 have the saved SP/PC.
1852	 * r23 is holding "r0 & 7" so we can test for alignment.
1853	 * The compare value is in r2/r3; the new value is in r4/r5.
1854	 * On return, we must put the old value in r0/r1.
1855	 */
1856	.align 64
1857.Lcmpxchg64:
1858	{
1859#if ATOMIC_LOCKS_FOUND_VIA_TABLE()
1860	 s2a	ATOMIC_LOCK_REG_NAME, r25, r21
1861#endif
1862	 bzt     r23, .Lcmpxchg64_tns
1863	}
1864	j       .Lcmpxchg_badaddr
1865
1866.Ldo_cmpxchg64:
1867	{
1868	 lw     r21, r0
1869	 addi   r25, r0, 4
1870	}
1871	{
1872	 lw     r1, r25
1873	}
1874	seq     r26, r21, r2
1875	{
1876	 bz     r26, .Lcmpxchg64_mismatch
1877	 seq    r26, r1, r3
1878	}
1879	{
1880	 bz     r26, .Lcmpxchg64_mismatch
1881	}
1882	sw      r0, r4
1883	sw      r25, r5
1884
1885	/*
1886	 * The 32-bit path provides optimized "match" and "mismatch"
1887	 * iret paths, but we don't have enough bundles in this cache line
1888	 * to do that, so we just make even the "mismatch" path do an "mf".
1889	 */
1890.Lcmpxchg64_mismatch:
1891	{
1892	 move   sp, r27
1893	 mtspr  SPR_EX_CONTEXT_K_0, r28
1894	}
1895	mf
1896	{
1897	 move   r0, r21
1898	 sw     ATOMIC_LOCK_REG_NAME, zero
1899	}
1900	iret
1901
1902.Lcmpxchg64_tns:
1903	cmpxchg_lock 64
1904
1905
1906	/*
1907	 * Reset sp and revector to sys_cmpxchg_badaddr(), which will
1908	 * just raise the appropriate signal and exit.  Doing it this
1909	 * way means we don't have to duplicate the code in intvec.S's
1910	 * int_hand macro that locates the top of the stack.
1911	 */
1912.Lcmpxchg_badaddr:
1913	{
1914	 moveli TREG_SYSCALL_NR_NAME, __NR_cmpxchg_badaddr
1915	 move   sp, r27
1916	}
1917	j       intvec_SWINT_1
1918	ENDPROC(sys_cmpxchg)
1919	ENTRY(__sys_cmpxchg_end)
1920
1921
1922/* The single-step support may need to read all the registers. */
1923int_unalign:
1924	push_extra_callee_saves r0
1925	j       do_trap
1926
1927/* Include .intrpt1 array of interrupt vectors */
1928	.section ".intrpt1", "ax"
1929
1930#define op_handle_perf_interrupt bad_intr
1931#define op_handle_aux_perf_interrupt bad_intr
1932
1933#ifndef CONFIG_HARDWALL
1934#define do_hardwall_trap bad_intr
1935#endif
1936
1937	int_hand     INT_ITLB_MISS, ITLB_MISS, \
1938		     do_page_fault, handle_interrupt_no_single_step
1939	int_hand     INT_MEM_ERROR, MEM_ERROR, bad_intr
1940	int_hand     INT_ILL, ILL, do_trap, handle_ill
1941	int_hand     INT_GPV, GPV, do_trap
1942	int_hand     INT_SN_ACCESS, SN_ACCESS, do_trap
1943	int_hand     INT_IDN_ACCESS, IDN_ACCESS, do_trap
1944	int_hand     INT_UDN_ACCESS, UDN_ACCESS, do_trap
1945	int_hand     INT_IDN_REFILL, IDN_REFILL, bad_intr
1946	int_hand     INT_UDN_REFILL, UDN_REFILL, bad_intr
1947	int_hand     INT_IDN_COMPLETE, IDN_COMPLETE, bad_intr
1948	int_hand     INT_UDN_COMPLETE, UDN_COMPLETE, bad_intr
1949	int_hand     INT_SWINT_3, SWINT_3, do_trap
1950	int_hand     INT_SWINT_2, SWINT_2, do_trap
1951	int_hand     INT_SWINT_1, SWINT_1, SYSCALL, handle_syscall
1952	int_hand     INT_SWINT_0, SWINT_0, do_trap
1953	int_hand     INT_UNALIGN_DATA, UNALIGN_DATA, int_unalign
1954	int_hand     INT_DTLB_MISS, DTLB_MISS, do_page_fault
1955	int_hand     INT_DTLB_ACCESS, DTLB_ACCESS, do_page_fault
1956	int_hand     INT_DMATLB_MISS, DMATLB_MISS, do_page_fault
1957	int_hand     INT_DMATLB_ACCESS, DMATLB_ACCESS, do_page_fault
1958	int_hand     INT_SNITLB_MISS, SNITLB_MISS, do_page_fault
1959	int_hand     INT_SN_NOTIFY, SN_NOTIFY, bad_intr
1960	int_hand     INT_SN_FIREWALL, SN_FIREWALL, do_hardwall_trap
1961	int_hand     INT_IDN_FIREWALL, IDN_FIREWALL, bad_intr
1962	int_hand     INT_UDN_FIREWALL, UDN_FIREWALL, do_hardwall_trap
1963	int_hand     INT_TILE_TIMER, TILE_TIMER, do_timer_interrupt
1964	int_hand     INT_IDN_TIMER, IDN_TIMER, bad_intr
1965	int_hand     INT_UDN_TIMER, UDN_TIMER, bad_intr
1966	int_hand     INT_DMA_NOTIFY, DMA_NOTIFY, bad_intr
1967	int_hand     INT_IDN_CA, IDN_CA, bad_intr
1968	int_hand     INT_UDN_CA, UDN_CA, bad_intr
1969	int_hand     INT_IDN_AVAIL, IDN_AVAIL, bad_intr
1970	int_hand     INT_UDN_AVAIL, UDN_AVAIL, bad_intr
1971	int_hand     INT_PERF_COUNT, PERF_COUNT, \
1972		     op_handle_perf_interrupt, handle_nmi
1973	int_hand     INT_INTCTRL_3, INTCTRL_3, bad_intr
1974#if CONFIG_KERNEL_PL == 2
1975	dc_dispatch  INT_INTCTRL_2, INTCTRL_2
1976	int_hand     INT_INTCTRL_1, INTCTRL_1, bad_intr
1977#else
1978	int_hand     INT_INTCTRL_2, INTCTRL_2, bad_intr
1979	dc_dispatch  INT_INTCTRL_1, INTCTRL_1
1980#endif
1981	int_hand     INT_INTCTRL_0, INTCTRL_0, bad_intr
1982	int_hand     INT_MESSAGE_RCV_DWNCL, MESSAGE_RCV_DWNCL, \
1983		     hv_message_intr
1984	int_hand     INT_DEV_INTR_DWNCL, DEV_INTR_DWNCL, \
1985		     tile_dev_intr
1986	int_hand     INT_I_ASID, I_ASID, bad_intr
1987	int_hand     INT_D_ASID, D_ASID, bad_intr
1988	int_hand     INT_DMATLB_MISS_DWNCL, DMATLB_MISS_DWNCL, \
1989		     do_page_fault
1990	int_hand     INT_SNITLB_MISS_DWNCL, SNITLB_MISS_DWNCL, \
1991		     do_page_fault
1992	int_hand     INT_DMATLB_ACCESS_DWNCL, DMATLB_ACCESS_DWNCL, \
1993		     do_page_fault
1994	int_hand     INT_SN_CPL, SN_CPL, bad_intr
1995	int_hand     INT_DOUBLE_FAULT, DOUBLE_FAULT, do_trap
1996#if CHIP_HAS_AUX_PERF_COUNTERS()
1997	int_hand     INT_AUX_PERF_COUNT, AUX_PERF_COUNT, \
1998		     op_handle_aux_perf_interrupt, handle_nmi
1999#endif
2000
2001	/* Synthetic interrupt delivered only by the simulator */
2002	int_hand     INT_BREAKPOINT, BREAKPOINT, do_breakpoint
2003