Merge rsync://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[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                 andcc                   %l1, TSTATE_PRIV, %l3
169                 and                     %l1, %l4, %l4
170                 bne,pn                  %icc, to_kernel
171                  andn                   %l1, %l4, %l1
172
173                 /* We must hold IRQs off and atomically test schedule+signal
174                  * state, then hold them off all the way back to userspace.
175                  * If we are returning to kernel, none of this matters.
176                  *
177                  * If we do not do this, there is a window where we would do
178                  * the tests, later the signal/resched event arrives but we do
179                  * not process it since we are still in kernel mode.  It would
180                  * take until the next local IRQ before the signal/resched
181                  * event would be handled.
182                  *
183                  * This also means that if we have to deal with performance
184                  * counters or user windows, we have to redo all of these
185                  * sched+signal checks with IRQs disabled.
186                  */
187 to_user:        wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
188                 wrpr                    0, %pil
189 __handle_preemption_continue:
190                 ldx                     [%g6 + TI_FLAGS], %l0
191                 sethi                   %hi(_TIF_USER_WORK_MASK), %o0
192                 or                      %o0, %lo(_TIF_USER_WORK_MASK), %o0
193                 andcc                   %l0, %o0, %g0
194                 sethi                   %hi(TSTATE_PEF), %o0
195                 be,pt                   %xcc, user_nowork
196                  andcc                  %l1, %o0, %g0
197                 andcc                   %l0, _TIF_NEED_RESCHED, %g0
198                 bne,pn                  %xcc, __handle_preemption
199                  andcc                  %l0, (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), %g0
200                 bne,pn                  %xcc, __handle_signal
201 __handle_signal_continue:
202                  ldub                   [%g6 + TI_WSAVED], %o2
203                 brnz,pn                 %o2, __handle_user_windows
204                  nop
205 __handle_user_windows_continue:
206                 ldx                     [%g6 + TI_FLAGS], %l5
207                 andcc                   %l5, _TIF_PERFCTR, %g0
208                 sethi                   %hi(TSTATE_PEF), %o0
209                 bne,pn                  %xcc, __handle_perfctrs
210 __handle_perfctrs_continue:
211                  andcc                  %l1, %o0, %g0
212
213                 /* This fpdepth clear is necessary for non-syscall rtraps only */
214 user_nowork:
215                 bne,pn                  %xcc, __handle_userfpu
216                  stb                    %g0, [%g6 + TI_FPDEPTH]
217 __handle_userfpu_continue:
218
219 rt_continue:    ldx                     [%sp + PTREGS_OFF + PT_V9_G1], %g1
220                 ldx                     [%sp + PTREGS_OFF + PT_V9_G2], %g2
221
222                 ldx                     [%sp + PTREGS_OFF + PT_V9_G3], %g3
223                 ldx                     [%sp + PTREGS_OFF + PT_V9_G4], %g4
224                 ldx                     [%sp + PTREGS_OFF + PT_V9_G5], %g5
225                 brz,pt                  %l3, 1f
226                 mov                     %g6, %l2
227
228                 /* Must do this before thread reg is clobbered below.  */
229                 LOAD_PER_CPU_BASE(%g5, %g6, %i0, %i1, %i2)
230 1:
231                 ldx                     [%sp + PTREGS_OFF + PT_V9_G6], %g6
232                 ldx                     [%sp + PTREGS_OFF + PT_V9_G7], %g7
233
234                 /* Normal globals are restored, go to trap globals.  */
235 661:            wrpr                    %g0, RTRAP_PSTATE_AG_IRQOFF, %pstate
236                 nop
237                 .section                .sun4v_2insn_patch, "ax"
238                 .word                   661b
239                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
240                 SET_GL(1)
241                 .previous
242
243                 mov                     %l2, %g6
244
245                 ldx                     [%sp + PTREGS_OFF + PT_V9_I0], %i0
246                 ldx                     [%sp + PTREGS_OFF + PT_V9_I1], %i1
247
248                 ldx                     [%sp + PTREGS_OFF + PT_V9_I2], %i2
249                 ldx                     [%sp + PTREGS_OFF + PT_V9_I3], %i3
250                 ldx                     [%sp + PTREGS_OFF + PT_V9_I4], %i4
251                 ldx                     [%sp + PTREGS_OFF + PT_V9_I5], %i5
252                 ldx                     [%sp + PTREGS_OFF + PT_V9_I6], %i6
253                 ldx                     [%sp + PTREGS_OFF + PT_V9_I7], %i7
254                 ldx                     [%sp + PTREGS_OFF + PT_V9_TPC], %l2
255                 ldx                     [%sp + PTREGS_OFF + PT_V9_TNPC], %o2
256
257                 ld                      [%sp + PTREGS_OFF + PT_V9_Y], %o3
258                 wr                      %o3, %g0, %y
259                 srl                     %l4, 20, %l4
260                 wrpr                    %l4, 0x0, %pil
261                 wrpr                    %g0, 0x1, %tl
262                 wrpr                    %l1, %g0, %tstate
263                 wrpr                    %l2, %g0, %tpc
264                 wrpr                    %o2, %g0, %tnpc
265
266                 brnz,pn                 %l3, kern_rtt
267                  mov                    PRIMARY_CONTEXT, %l7
268
269 661:            ldxa                    [%l7 + %l7] ASI_DMMU, %l0
270                 .section                .sun4v_1insn_patch, "ax"
271                 .word                   661b
272                 ldxa                    [%l7 + %l7] ASI_MMU, %l0
273                 .previous
274
275                 sethi                   %hi(sparc64_kern_pri_nuc_bits), %l1
276                 ldx                     [%l1 + %lo(sparc64_kern_pri_nuc_bits)], %l1
277                 or                      %l0, %l1, %l0
278
279 661:            stxa                    %l0, [%l7] ASI_DMMU
280                 .section                .sun4v_1insn_patch, "ax"
281                 .word                   661b
282                 stxa                    %l0, [%l7] ASI_MMU
283                 .previous
284
285                 sethi                   %hi(KERNBASE), %l7
286                 flush                   %l7
287                 rdpr                    %wstate, %l1
288                 rdpr                    %otherwin, %l2
289                 srl                     %l1, 3, %l1
290
291                 wrpr                    %l2, %g0, %canrestore
292                 wrpr                    %l1, %g0, %wstate
293                 brnz,pt                 %l2, user_rtt_restore
294                  wrpr                   %g0, %g0, %otherwin
295
296                 ldx                     [%g6 + TI_FLAGS], %g3
297                 wr                      %g0, ASI_AIUP, %asi
298                 rdpr                    %cwp, %g1
299                 andcc                   %g3, _TIF_32BIT, %g0
300                 sub                     %g1, 1, %g1
301                 bne,pt                  %xcc, user_rtt_fill_32bit
302                  wrpr                   %g1, %cwp
303                 ba,a,pt                 %xcc, user_rtt_fill_64bit
304
305 user_rtt_fill_fixup:
306                 rdpr    %cwp, %g1
307                 add     %g1, 1, %g1
308                 wrpr    %g1, 0x0, %cwp
309
310                 rdpr    %wstate, %g2
311                 sll     %g2, 3, %g2
312                 wrpr    %g2, 0x0, %wstate
313
314                 /* We know %canrestore and %otherwin are both zero.  */
315
316                 sethi   %hi(sparc64_kern_pri_context), %g2
317                 ldx     [%g2 + %lo(sparc64_kern_pri_context)], %g2
318                 mov     PRIMARY_CONTEXT, %g1
319
320 661:            stxa    %g2, [%g1] ASI_DMMU
321                 .section .sun4v_1insn_patch, "ax"
322                 .word   661b
323                 stxa    %g2, [%g1] ASI_MMU
324                 .previous
325
326                 sethi   %hi(KERNBASE), %g1
327                 flush   %g1
328
329                 or      %g4, FAULT_CODE_WINFIXUP, %g4
330                 stb     %g4, [%g6 + TI_FAULT_CODE]
331                 stx     %g5, [%g6 + TI_FAULT_ADDR]
332
333                 mov     %g6, %l1
334                 wrpr    %g0, 0x0, %tl
335
336 661:            nop
337                 .section                .sun4v_1insn_patch, "ax"
338                 .word                   661b
339                 SET_GL(0)
340                 .previous
341
342                 wrpr    %g0, RTRAP_PSTATE, %pstate
343
344                 mov     %l1, %g6
345                 ldx     [%g6 + TI_TASK], %g4
346                 LOAD_PER_CPU_BASE(%g5, %g6, %g1, %g2, %g3)
347                 call    do_sparc64_fault
348                  add    %sp, PTREGS_OFF, %o0
349                 ba,pt   %xcc, rtrap
350                  nop
351
352 user_rtt_pre_restore:
353                 add                     %g1, 1, %g1
354                 wrpr                    %g1, 0x0, %cwp
355
356 user_rtt_restore:
357                 restore
358                 rdpr                    %canrestore, %g1
359                 wrpr                    %g1, 0x0, %cleanwin
360                 retry
361                 nop
362
363 kern_rtt:       rdpr                    %canrestore, %g1
364                 brz,pn                  %g1, kern_rtt_fill
365                  nop
366 kern_rtt_restore:
367                 restore
368                 retry
369
370 to_kernel:
371 #ifdef CONFIG_PREEMPT
372                 ldsw                    [%g6 + TI_PRE_COUNT], %l5
373                 brnz                    %l5, kern_fpucheck
374                  ldx                    [%g6 + TI_FLAGS], %l5
375                 andcc                   %l5, _TIF_NEED_RESCHED, %g0
376                 be,pt                   %xcc, kern_fpucheck
377                  srl                    %l4, 20, %l5
378                 cmp                     %l5, 0
379                 bne,pn                  %xcc, kern_fpucheck
380                  sethi                  %hi(PREEMPT_ACTIVE), %l6
381                 stw                     %l6, [%g6 + TI_PRE_COUNT]
382                 call                    schedule
383                  nop
384                 ba,pt                   %xcc, rtrap
385                  stw                    %g0, [%g6 + TI_PRE_COUNT]
386 #endif
387 kern_fpucheck:  ldub                    [%g6 + TI_FPDEPTH], %l5
388                 brz,pt                  %l5, rt_continue
389                  srl                    %l5, 1, %o0
390                 add                     %g6, TI_FPSAVED, %l6
391                 ldub                    [%l6 + %o0], %l2
392                 sub                     %l5, 2, %l5
393
394                 add                     %g6, TI_GSR, %o1
395                 andcc                   %l2, (FPRS_FEF|FPRS_DU), %g0
396                 be,pt                   %icc, 2f
397                  and                    %l2, FPRS_DL, %l6
398                 andcc                   %l2, FPRS_FEF, %g0
399                 be,pn                   %icc, 5f
400                  sll                    %o0, 3, %o5
401                 rd                      %fprs, %g1
402
403                 wr                      %g1, FPRS_FEF, %fprs
404                 ldx                     [%o1 + %o5], %g1
405                 add                     %g6, TI_XFSR, %o1
406                 sll                     %o0, 8, %o2
407                 add                     %g6, TI_FPREGS, %o3
408                 brz,pn                  %l6, 1f
409                  add                    %g6, TI_FPREGS+0x40, %o4
410
411                 membar                  #Sync
412                 ldda                    [%o3 + %o2] ASI_BLK_P, %f0
413                 ldda                    [%o4 + %o2] ASI_BLK_P, %f16
414                 membar                  #Sync
415 1:              andcc                   %l2, FPRS_DU, %g0
416                 be,pn                   %icc, 1f
417                  wr                     %g1, 0, %gsr
418                 add                     %o2, 0x80, %o2
419                 membar                  #Sync
420                 ldda                    [%o3 + %o2] ASI_BLK_P, %f32
421                 ldda                    [%o4 + %o2] ASI_BLK_P, %f48
422 1:              membar                  #Sync
423                 ldx                     [%o1 + %o5], %fsr
424 2:              stb                     %l5, [%g6 + TI_FPDEPTH]
425                 ba,pt                   %xcc, rt_continue
426                  nop
427 5:              wr                      %g0, FPRS_FEF, %fprs
428                 sll                     %o0, 8, %o2
429
430                 add                     %g6, TI_FPREGS+0x80, %o3
431                 add                     %g6, TI_FPREGS+0xc0, %o4
432                 membar                  #Sync
433                 ldda                    [%o3 + %o2] ASI_BLK_P, %f32
434                 ldda                    [%o4 + %o2] ASI_BLK_P, %f48
435                 membar                  #Sync
436                 wr                      %g0, FPRS_DU, %fprs
437                 ba,pt                   %xcc, rt_continue
438                  stb                    %l5, [%g6 + TI_FPDEPTH]