Merge ../linus
[linux-2.6] / arch / sparc64 / kernel / rtrap.S
1 /* $Id: rtrap.S,v 1.61 2002/02/09 19:49:31 davem Exp $
2  * rtrap.S: Preparing for return from trap on Sparc V9.
3  *
4  * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
5  * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
6  */
7
8
9 #include <asm/asi.h>
10 #include <asm/pstate.h>
11 #include <asm/ptrace.h>
12 #include <asm/spitfire.h>
13 #include <asm/head.h>
14 #include <asm/visasm.h>
15 #include <asm/processor.h>
16
17 #define         RTRAP_PSTATE            (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV|PSTATE_IE)
18 #define         RTRAP_PSTATE_IRQOFF     (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV)
19 #define         RTRAP_PSTATE_AG_IRQOFF  (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV|PSTATE_AG)
20
21                 /* Register %l6 keeps track of whether we are returning
22                  * from a system call or not.  It is cleared if we call
23                  * do_notify_resume, and it must not be otherwise modified
24                  * until we fully commit to returning to userspace.
25                  */
26
27                 .text
28                 .align                  32
29 __handle_softirq:
30                 call                    do_softirq
31                  nop
32                 ba,a,pt                 %xcc, __handle_softirq_continue
33                  nop
34 __handle_preemption:
35                 call                    schedule
36                  wrpr                   %g0, RTRAP_PSTATE, %pstate
37                 ba,pt                   %xcc, __handle_preemption_continue
38                  wrpr                   %g0, RTRAP_PSTATE_IRQOFF, %pstate
39
40 __handle_user_windows:
41                 call                    fault_in_user_windows
42                  wrpr                   %g0, RTRAP_PSTATE, %pstate
43                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
44                 /* Redo sched+sig checks */
45                 ldx                     [%g6 + TI_FLAGS], %l0
46                 andcc                   %l0, _TIF_NEED_RESCHED, %g0
47
48                 be,pt                   %xcc, 1f
49                  nop
50                 call                    schedule
51                  wrpr                   %g0, RTRAP_PSTATE, %pstate
52                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
53                 ldx                     [%g6 + TI_FLAGS], %l0
54
55 1:              andcc                   %l0, (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), %g0
56                 be,pt                   %xcc, __handle_user_windows_continue
57                  nop
58                 mov                     %l5, %o1
59                 mov                     %l6, %o2
60                 add                     %sp, PTREGS_OFF, %o0
61                 mov                     %l0, %o3
62
63                 call                    do_notify_resume
64                  wrpr                   %g0, RTRAP_PSTATE, %pstate
65                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
66                 clr                     %l6
67                 /* Signal delivery can modify pt_regs tstate, so we must
68                  * reload it.
69                  */
70                 ldx                     [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
71                 sethi                   %hi(0xf << 20), %l4
72                 and                     %l1, %l4, %l4
73                 ba,pt                   %xcc, __handle_user_windows_continue
74
75                  andn                   %l1, %l4, %l1
76 __handle_perfctrs:
77                 call                    update_perfctrs
78                  wrpr                   %g0, RTRAP_PSTATE, %pstate
79                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
80                 ldub                    [%g6 + TI_WSAVED], %o2
81                 brz,pt                  %o2, 1f
82                  nop
83                 /* Redo userwin+sched+sig checks */
84                 call                    fault_in_user_windows
85
86                  wrpr                   %g0, RTRAP_PSTATE, %pstate
87                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
88                 ldx                     [%g6 + TI_FLAGS], %l0
89                 andcc                   %l0, _TIF_NEED_RESCHED, %g0
90                 be,pt                   %xcc, 1f
91
92                  nop
93                 call                    schedule
94                  wrpr                   %g0, RTRAP_PSTATE, %pstate
95                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
96                 ldx                     [%g6 + TI_FLAGS], %l0
97 1:              andcc                   %l0, (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), %g0
98
99                 be,pt                   %xcc, __handle_perfctrs_continue
100                  sethi                  %hi(TSTATE_PEF), %o0
101                 mov                     %l5, %o1
102                 mov                     %l6, %o2
103                 add                     %sp, PTREGS_OFF, %o0
104                 mov                     %l0, %o3
105                 call                    do_notify_resume
106
107                  wrpr                   %g0, RTRAP_PSTATE, %pstate
108                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
109                 clr                     %l6
110                 /* Signal delivery can modify pt_regs tstate, so we must
111                  * reload it.
112                  */
113                 ldx                     [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
114                 sethi                   %hi(0xf << 20), %l4
115                 and                     %l1, %l4, %l4
116                 andn                    %l1, %l4, %l1
117                 ba,pt                   %xcc, __handle_perfctrs_continue
118
119                  sethi                  %hi(TSTATE_PEF), %o0
120 __handle_userfpu:
121                 rd                      %fprs, %l5
122                 andcc                   %l5, FPRS_FEF, %g0
123                 sethi                   %hi(TSTATE_PEF), %o0
124                 be,a,pn                 %icc, __handle_userfpu_continue
125                  andn                   %l1, %o0, %l1
126                 ba,a,pt                 %xcc, __handle_userfpu_continue
127
128 __handle_signal:
129                 mov                     %l5, %o1
130                 mov                     %l6, %o2
131                 add                     %sp, PTREGS_OFF, %o0
132                 mov                     %l0, %o3
133                 call                    do_notify_resume
134                  wrpr                   %g0, RTRAP_PSTATE, %pstate
135                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
136                 clr                     %l6
137
138                 /* Signal delivery can modify pt_regs tstate, so we must
139                  * reload it.
140                  */
141                 ldx                     [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
142                 sethi                   %hi(0xf << 20), %l4
143                 and                     %l1, %l4, %l4
144                 ba,pt                   %xcc, __handle_signal_continue
145                  andn                   %l1, %l4, %l1
146
147                 .align                  64
148                 .globl                  rtrap_irq, rtrap_clr_l6, rtrap, irqsz_patchme, rtrap_xcall
149 rtrap_irq:
150 rtrap_clr_l6:   clr                     %l6
151 rtrap:
152 #ifndef CONFIG_SMP
153                 sethi                   %hi(per_cpu____cpu_data), %l0
154                 lduw                    [%l0 + %lo(per_cpu____cpu_data)], %l1
155 #else
156                 sethi                   %hi(per_cpu____cpu_data), %l0
157                 or                      %l0, %lo(per_cpu____cpu_data), %l0
158                 lduw                    [%l0 + %g5], %l1
159 #endif
160                 cmp                     %l1, 0
161
162                 /* mm/ultra.S:xcall_report_regs KNOWS about this load. */
163                 bne,pn                  %icc, __handle_softirq
164                  ldx                    [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
165 __handle_softirq_continue:
166 rtrap_xcall:
167                 sethi                   %hi(0xf << 20), %l4
168                 and                     %l1, %l4, %l4
169                 andn                    %l1, %l4, %l1
170                 srl                     %l4, 20, %l4
171 #ifdef CONFIG_TRACE_IRQFLAGS
172                 brnz,pn                 %l4, rtrap_no_irq_enable
173                  nop
174                 call                    trace_hardirqs_on
175                  nop
176                 wrpr                    %l4, %pil
177 rtrap_no_irq_enable:
178 #endif
179                 andcc                   %l1, TSTATE_PRIV, %l3
180                 bne,pn                  %icc, to_kernel
181                  nop
182
183                 /* We must hold IRQs off and atomically test schedule+signal
184                  * state, then hold them off all the way back to userspace.
185                  * If we are returning to kernel, none of this matters.  Note
186                  * that we are disabling interrupts via PSTATE_IE, not using
187                  * %pil.
188                  *
189                  * If we do not do this, there is a window where we would do
190                  * the tests, later the signal/resched event arrives but we do
191                  * not process it since we are still in kernel mode.  It would
192                  * take until the next local IRQ before the signal/resched
193                  * event would be handled.
194                  *
195                  * This also means that if we have to deal with performance
196                  * counters or user windows, we have to redo all of these
197                  * sched+signal checks with IRQs disabled.
198                  */
199 to_user:        wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
200                 wrpr                    0, %pil
201 __handle_preemption_continue:
202                 ldx                     [%g6 + TI_FLAGS], %l0
203                 sethi                   %hi(_TIF_USER_WORK_MASK), %o0
204                 or                      %o0, %lo(_TIF_USER_WORK_MASK), %o0
205                 andcc                   %l0, %o0, %g0
206                 sethi                   %hi(TSTATE_PEF), %o0
207                 be,pt                   %xcc, user_nowork
208                  andcc                  %l1, %o0, %g0
209                 andcc                   %l0, _TIF_NEED_RESCHED, %g0
210                 bne,pn                  %xcc, __handle_preemption
211                  andcc                  %l0, (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), %g0
212                 bne,pn                  %xcc, __handle_signal
213 __handle_signal_continue:
214                  ldub                   [%g6 + TI_WSAVED], %o2
215                 brnz,pn                 %o2, __handle_user_windows
216                  nop
217 __handle_user_windows_continue:
218                 ldx                     [%g6 + TI_FLAGS], %l5
219                 andcc                   %l5, _TIF_PERFCTR, %g0
220                 sethi                   %hi(TSTATE_PEF), %o0
221                 bne,pn                  %xcc, __handle_perfctrs
222 __handle_perfctrs_continue:
223                  andcc                  %l1, %o0, %g0
224
225                 /* This fpdepth clear is necessary for non-syscall rtraps only */
226 user_nowork:
227                 bne,pn                  %xcc, __handle_userfpu
228                  stb                    %g0, [%g6 + TI_FPDEPTH]
229 __handle_userfpu_continue:
230
231 rt_continue:    ldx                     [%sp + PTREGS_OFF + PT_V9_G1], %g1
232                 ldx                     [%sp + PTREGS_OFF + PT_V9_G2], %g2
233
234                 ldx                     [%sp + PTREGS_OFF + PT_V9_G3], %g3
235                 ldx                     [%sp + PTREGS_OFF + PT_V9_G4], %g4
236                 ldx                     [%sp + PTREGS_OFF + PT_V9_G5], %g5
237                 brz,pt                  %l3, 1f
238                 mov                     %g6, %l2
239
240                 /* Must do this before thread reg is clobbered below.  */
241                 LOAD_PER_CPU_BASE(%g5, %g6, %i0, %i1, %i2)
242 1:
243                 ldx                     [%sp + PTREGS_OFF + PT_V9_G6], %g6
244                 ldx                     [%sp + PTREGS_OFF + PT_V9_G7], %g7
245
246                 /* Normal globals are restored, go to trap globals.  */
247 661:            wrpr                    %g0, RTRAP_PSTATE_AG_IRQOFF, %pstate
248                 nop
249                 .section                .sun4v_2insn_patch, "ax"
250                 .word                   661b
251                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
252                 SET_GL(1)
253                 .previous
254
255                 mov                     %l2, %g6
256
257                 ldx                     [%sp + PTREGS_OFF + PT_V9_I0], %i0
258                 ldx                     [%sp + PTREGS_OFF + PT_V9_I1], %i1
259
260                 ldx                     [%sp + PTREGS_OFF + PT_V9_I2], %i2
261                 ldx                     [%sp + PTREGS_OFF + PT_V9_I3], %i3
262                 ldx                     [%sp + PTREGS_OFF + PT_V9_I4], %i4
263                 ldx                     [%sp + PTREGS_OFF + PT_V9_I5], %i5
264                 ldx                     [%sp + PTREGS_OFF + PT_V9_I6], %i6
265                 ldx                     [%sp + PTREGS_OFF + PT_V9_I7], %i7
266                 ldx                     [%sp + PTREGS_OFF + PT_V9_TPC], %l2
267                 ldx                     [%sp + PTREGS_OFF + PT_V9_TNPC], %o2
268
269                 ld                      [%sp + PTREGS_OFF + PT_V9_Y], %o3
270                 wr                      %o3, %g0, %y
271                 wrpr                    %l4, 0x0, %pil
272                 wrpr                    %g0, 0x1, %tl
273                 wrpr                    %l1, %g0, %tstate
274                 wrpr                    %l2, %g0, %tpc
275                 wrpr                    %o2, %g0, %tnpc
276
277                 brnz,pn                 %l3, kern_rtt
278                  mov                    PRIMARY_CONTEXT, %l7
279
280 661:            ldxa                    [%l7 + %l7] ASI_DMMU, %l0
281                 .section                .sun4v_1insn_patch, "ax"
282                 .word                   661b
283                 ldxa                    [%l7 + %l7] ASI_MMU, %l0
284                 .previous
285
286                 sethi                   %hi(sparc64_kern_pri_nuc_bits), %l1
287                 ldx                     [%l1 + %lo(sparc64_kern_pri_nuc_bits)], %l1
288                 or                      %l0, %l1, %l0
289
290 661:            stxa                    %l0, [%l7] ASI_DMMU
291                 .section                .sun4v_1insn_patch, "ax"
292                 .word                   661b
293                 stxa                    %l0, [%l7] ASI_MMU
294                 .previous
295
296                 sethi                   %hi(KERNBASE), %l7
297                 flush                   %l7
298                 rdpr                    %wstate, %l1
299                 rdpr                    %otherwin, %l2
300                 srl                     %l1, 3, %l1
301
302                 wrpr                    %l2, %g0, %canrestore
303                 wrpr                    %l1, %g0, %wstate
304                 brnz,pt                 %l2, user_rtt_restore
305                  wrpr                   %g0, %g0, %otherwin
306
307                 ldx                     [%g6 + TI_FLAGS], %g3
308                 wr                      %g0, ASI_AIUP, %asi
309                 rdpr                    %cwp, %g1
310                 andcc                   %g3, _TIF_32BIT, %g0
311                 sub                     %g1, 1, %g1
312                 bne,pt                  %xcc, user_rtt_fill_32bit
313                  wrpr                   %g1, %cwp
314                 ba,a,pt                 %xcc, user_rtt_fill_64bit
315
316 user_rtt_fill_fixup:
317                 rdpr    %cwp, %g1
318                 add     %g1, 1, %g1
319                 wrpr    %g1, 0x0, %cwp
320
321                 rdpr    %wstate, %g2
322                 sll     %g2, 3, %g2
323                 wrpr    %g2, 0x0, %wstate
324
325                 /* We know %canrestore and %otherwin are both zero.  */
326
327                 sethi   %hi(sparc64_kern_pri_context), %g2
328                 ldx     [%g2 + %lo(sparc64_kern_pri_context)], %g2
329                 mov     PRIMARY_CONTEXT, %g1
330
331 661:            stxa    %g2, [%g1] ASI_DMMU
332                 .section .sun4v_1insn_patch, "ax"
333                 .word   661b
334                 stxa    %g2, [%g1] ASI_MMU
335                 .previous
336
337                 sethi   %hi(KERNBASE), %g1
338                 flush   %g1
339
340                 or      %g4, FAULT_CODE_WINFIXUP, %g4
341                 stb     %g4, [%g6 + TI_FAULT_CODE]
342                 stx     %g5, [%g6 + TI_FAULT_ADDR]
343
344                 mov     %g6, %l1
345                 wrpr    %g0, 0x0, %tl
346
347 661:            nop
348                 .section                .sun4v_1insn_patch, "ax"
349                 .word                   661b
350                 SET_GL(0)
351                 .previous
352
353                 wrpr    %g0, RTRAP_PSTATE, %pstate
354
355                 mov     %l1, %g6
356                 ldx     [%g6 + TI_TASK], %g4
357                 LOAD_PER_CPU_BASE(%g5, %g6, %g1, %g2, %g3)
358                 call    do_sparc64_fault
359                  add    %sp, PTREGS_OFF, %o0
360                 ba,pt   %xcc, rtrap
361                  nop
362
363 user_rtt_pre_restore:
364                 add                     %g1, 1, %g1
365                 wrpr                    %g1, 0x0, %cwp
366
367 user_rtt_restore:
368                 restore
369                 rdpr                    %canrestore, %g1
370                 wrpr                    %g1, 0x0, %cleanwin
371                 retry
372                 nop
373
374 kern_rtt:       rdpr                    %canrestore, %g1
375                 brz,pn                  %g1, kern_rtt_fill
376                  nop
377 kern_rtt_restore:
378                 restore
379                 retry
380
381 to_kernel:
382 #ifdef CONFIG_PREEMPT
383                 ldsw                    [%g6 + TI_PRE_COUNT], %l5
384                 brnz                    %l5, kern_fpucheck
385                  ldx                    [%g6 + TI_FLAGS], %l5
386                 andcc                   %l5, _TIF_NEED_RESCHED, %g0
387                 be,pt                   %xcc, kern_fpucheck
388                  nop
389                 cmp                     %l4, 0
390                 bne,pn                  %xcc, kern_fpucheck
391                  sethi                  %hi(PREEMPT_ACTIVE), %l6
392                 stw                     %l6, [%g6 + TI_PRE_COUNT]
393                 call                    schedule
394                  nop
395                 ba,pt                   %xcc, rtrap
396                  stw                    %g0, [%g6 + TI_PRE_COUNT]
397 #endif
398 kern_fpucheck:  ldub                    [%g6 + TI_FPDEPTH], %l5
399                 brz,pt                  %l5, rt_continue
400                  srl                    %l5, 1, %o0
401                 add                     %g6, TI_FPSAVED, %l6
402                 ldub                    [%l6 + %o0], %l2
403                 sub                     %l5, 2, %l5
404
405                 add                     %g6, TI_GSR, %o1
406                 andcc                   %l2, (FPRS_FEF|FPRS_DU), %g0
407                 be,pt                   %icc, 2f
408                  and                    %l2, FPRS_DL, %l6
409                 andcc                   %l2, FPRS_FEF, %g0
410                 be,pn                   %icc, 5f
411                  sll                    %o0, 3, %o5
412                 rd                      %fprs, %g1
413
414                 wr                      %g1, FPRS_FEF, %fprs
415                 ldx                     [%o1 + %o5], %g1
416                 add                     %g6, TI_XFSR, %o1
417                 sll                     %o0, 8, %o2
418                 add                     %g6, TI_FPREGS, %o3
419                 brz,pn                  %l6, 1f
420                  add                    %g6, TI_FPREGS+0x40, %o4
421
422                 membar                  #Sync
423                 ldda                    [%o3 + %o2] ASI_BLK_P, %f0
424                 ldda                    [%o4 + %o2] ASI_BLK_P, %f16
425                 membar                  #Sync
426 1:              andcc                   %l2, FPRS_DU, %g0
427                 be,pn                   %icc, 1f
428                  wr                     %g1, 0, %gsr
429                 add                     %o2, 0x80, %o2
430                 membar                  #Sync
431                 ldda                    [%o3 + %o2] ASI_BLK_P, %f32
432                 ldda                    [%o4 + %o2] ASI_BLK_P, %f48
433 1:              membar                  #Sync
434                 ldx                     [%o1 + %o5], %fsr
435 2:              stb                     %l5, [%g6 + TI_FPDEPTH]
436                 ba,pt                   %xcc, rt_continue
437                  nop
438 5:              wr                      %g0, FPRS_FEF, %fprs
439                 sll                     %o0, 8, %o2
440
441                 add                     %g6, TI_FPREGS+0x80, %o3
442                 add                     %g6, TI_FPREGS+0xc0, %o4
443                 membar                  #Sync
444                 ldda                    [%o3 + %o2] ASI_BLK_P, %f32
445                 ldda                    [%o4 + %o2] ASI_BLK_P, %f48
446                 membar                  #Sync
447                 wr                      %g0, FPRS_DU, %fprs
448                 ba,pt                   %xcc, rt_continue
449                  stb                    %l5, [%g6 + TI_FPDEPTH]