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review.evervolv.com / android_kernel_htc_msm8960 / 3487d1d4414fbfab5d98ec559e6f84f55520cb15 / . / arch / sparc64 / kernel / winfixup.S
blob: c0545d089c96b33803555c36e355711ba0a276c9 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]1/* $Id: winfixup.S,v 1.30 2002/02/09 19:49:30 davem Exp $
2 *
3 * winfixup.S: Handle cases where user stack pointer is found to be bogus.
4 *
5 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
6 */
7
8#include <asm/asi.h>
9#include <asm/head.h>
10#include <asm/page.h>
11#include <asm/ptrace.h>
12#include <asm/processor.h>
13#include <asm/spitfire.h>
14#include <asm/thread_info.h>
15
16 .text
17
18set_pcontext:
David S. Miller0835ae02005-10-04 15:23:20 -0700[diff] [blame]19 sethi %hi(sparc64_kern_pri_context), %l1
20 ldx [%l1 + %lo(sparc64_kern_pri_context)], %l1
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]21 mov PRIMARY_CONTEXT, %g1
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]22 stxa %l1, [%g1] ASI_DMMU
David S. Miller4da808c2006-01-31 18:33:00 -0800[diff] [blame]23 sethi %hi(KERNBASE), %l1
24 flush %l1
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]25 retl
26 nop
27
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]28 .align 32
29
30 /* Here are the rules, pay attention.
31 *
32 * The kernel is disallowed from touching user space while
33 * the trap level is greater than zero, except for from within
34 * the window spill/fill handlers. This must be followed
35 * so that we can easily detect the case where we tried to
36 * spill/fill with a bogus (or unmapped) user stack pointer.
37 *
38 * These are layed out in a special way for cache reasons,
39 * don't touch...
40 */
41 .globl fill_fixup, spill_fixup
42fill_fixup:
David S. Miller56fb4df2006-02-26 23:24:22 -0800[diff] [blame]43 TRAP_LOAD_THREAD_REG
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]44 rdpr %tstate, %g1
45 andcc %g1, TSTATE_PRIV, %g0
46 or %g4, FAULT_CODE_WINFIXUP, %g4
47 be,pt %xcc, window_scheisse_from_user_common
48 and %g1, TSTATE_CWP, %g1
49
50 /* This is the extremely complex case, but it does happen from
51 * time to time if things are just right. Essentially the restore
52 * done in rtrap right before going back to user mode, with tl=1
53 * and that levels trap stack registers all setup, took a fill trap,
54 * the user stack was not mapped in the tlb, and tlb miss occurred,
55 * the pte found was not valid, and a simple ref bit watch update
56 * could not satisfy the miss, so we got here.
57 *
58 * We must carefully unwind the state so we get back to tl=0, preserve
59 * all the register values we were going to give to the user. Luckily
60 * most things are where they need to be, we also have the address
61 * which triggered the fault handy as well.
62 *
63 * Also note that we must preserve %l5 and %l6. If the user was
64 * returning from a system call, we must make it look this way
65 * after we process the fill fault on the users stack.
66 *
67 * First, get into the window where the original restore was executed.
68 */
69
70 rdpr %wstate, %g2 ! Grab user mode wstate.
71 wrpr %g1, %cwp ! Get into the right window.
72 sll %g2, 3, %g2 ! NORMAL-->OTHER
73
74 wrpr %g0, 0x0, %canrestore ! Standard etrap stuff.
75 wrpr %g2, 0x0, %wstate ! This must be consistent.
76 wrpr %g0, 0x0, %otherwin ! We know this.
77 call set_pcontext ! Change contexts...
78 nop
79 rdpr %pstate, %l1 ! Prepare to change globals.
80 mov %g6, %o7 ! Get current.
81
82 andn %l1, PSTATE_MM, %l1 ! We want to be in RMO
83 stb %g4, [%g6 + TI_FAULT_CODE]
84 stx %g5, [%g6 + TI_FAULT_ADDR]
85 wrpr %g0, 0x0, %tl ! Out of trap levels.
86 wrpr %l1, (PSTATE_IE | PSTATE_AG | PSTATE_RMO), %pstate
87 mov %o7, %g6
88 ldx [%g6 + TI_TASK], %g4
David S. Miller56fb4df2006-02-26 23:24:22 -0800[diff] [blame]89 LOAD_PER_CPU_BASE(%g1, %g2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]90
91 /* This is the same as below, except we handle this a bit special
92 * since we must preserve %l5 and %l6, see comment above.
93 */
94 call do_sparc64_fault
95 add %sp, PTREGS_OFF, %o0
96 ba,pt %xcc, rtrap
97 nop ! yes, nop is correct
98
99 /* Be very careful about usage of the alternate globals here.
100 * You cannot touch %g4/%g5 as that has the fault information
101 * should this be from usermode. Also be careful for the case
102 * where we get here from the save instruction in etrap.S when
103 * coming from either user or kernel (does not matter which, it
104 * is the same problem in both cases). Essentially this means
105 * do not touch %g7 or %g2 so we handle the two cases fine.
106 */
107spill_fixup:
David S. Miller56fb4df2006-02-26 23:24:22 -0800[diff] [blame]108 TRAP_LOAD_THREAD_REG
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]109 ldx [%g6 + TI_FLAGS], %g1
110 andcc %g1, _TIF_32BIT, %g0
111 ldub [%g6 + TI_WSAVED], %g1
112
113 sll %g1, 3, %g3
114 add %g6, %g3, %g3
115 stx %sp, [%g3 + TI_RWIN_SPTRS]
116 sll %g1, 7, %g3
117 bne,pt %xcc, 1f
118 add %g6, %g3, %g3
119 stx %l0, [%g3 + TI_REG_WINDOW + 0x00]
120 stx %l1, [%g3 + TI_REG_WINDOW + 0x08]
121
122 stx %l2, [%g3 + TI_REG_WINDOW + 0x10]
123 stx %l3, [%g3 + TI_REG_WINDOW + 0x18]
124 stx %l4, [%g3 + TI_REG_WINDOW + 0x20]
125 stx %l5, [%g3 + TI_REG_WINDOW + 0x28]
126 stx %l6, [%g3 + TI_REG_WINDOW + 0x30]
127 stx %l7, [%g3 + TI_REG_WINDOW + 0x38]
128 stx %i0, [%g3 + TI_REG_WINDOW + 0x40]
129 stx %i1, [%g3 + TI_REG_WINDOW + 0x48]
130
131 stx %i2, [%g3 + TI_REG_WINDOW + 0x50]
132 stx %i3, [%g3 + TI_REG_WINDOW + 0x58]
133 stx %i4, [%g3 + TI_REG_WINDOW + 0x60]
134 stx %i5, [%g3 + TI_REG_WINDOW + 0x68]
135 stx %i6, [%g3 + TI_REG_WINDOW + 0x70]
136 b,pt %xcc, 2f
137 stx %i7, [%g3 + TI_REG_WINDOW + 0x78]
1381: stw %l0, [%g3 + TI_REG_WINDOW + 0x00]
139
140 stw %l1, [%g3 + TI_REG_WINDOW + 0x04]
141 stw %l2, [%g3 + TI_REG_WINDOW + 0x08]
142 stw %l3, [%g3 + TI_REG_WINDOW + 0x0c]
143 stw %l4, [%g3 + TI_REG_WINDOW + 0x10]
144 stw %l5, [%g3 + TI_REG_WINDOW + 0x14]
145 stw %l6, [%g3 + TI_REG_WINDOW + 0x18]
146 stw %l7, [%g3 + TI_REG_WINDOW + 0x1c]
147 stw %i0, [%g3 + TI_REG_WINDOW + 0x20]
148
149 stw %i1, [%g3 + TI_REG_WINDOW + 0x24]
150 stw %i2, [%g3 + TI_REG_WINDOW + 0x28]
151 stw %i3, [%g3 + TI_REG_WINDOW + 0x2c]
152 stw %i4, [%g3 + TI_REG_WINDOW + 0x30]
153 stw %i5, [%g3 + TI_REG_WINDOW + 0x34]
154 stw %i6, [%g3 + TI_REG_WINDOW + 0x38]
155 stw %i7, [%g3 + TI_REG_WINDOW + 0x3c]
1562: add %g1, 1, %g1
157
158 stb %g1, [%g6 + TI_WSAVED]
159 rdpr %tstate, %g1
160 andcc %g1, TSTATE_PRIV, %g0
161 saved
162 and %g1, TSTATE_CWP, %g1
163 be,pn %xcc, window_scheisse_from_user_common
164 mov FAULT_CODE_WRITE | FAULT_CODE_DTLB | FAULT_CODE_WINFIXUP, %g4
165 retry
166
167window_scheisse_from_user_common:
168 stb %g4, [%g6 + TI_FAULT_CODE]
169 stx %g5, [%g6 + TI_FAULT_ADDR]
170 wrpr %g1, %cwp
171 ba,pt %xcc, etrap
172 rd %pc, %g7
173 call do_sparc64_fault
174 add %sp, PTREGS_OFF, %o0
175 ba,a,pt %xcc, rtrap_clr_l6
176
177 .globl winfix_mna, fill_fixup_mna, spill_fixup_mna
178winfix_mna:
179 andn %g3, 0x7f, %g3
180 add %g3, 0x78, %g3
181 wrpr %g3, %tnpc
182 done
183fill_fixup_mna:
David S. Miller56fb4df2006-02-26 23:24:22 -0800[diff] [blame]184 TRAP_LOAD_THREAD_REG
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]185 rdpr %tstate, %g1
186 andcc %g1, TSTATE_PRIV, %g0
187 be,pt %xcc, window_mna_from_user_common
188 and %g1, TSTATE_CWP, %g1
189
190 /* Please, see fill_fixup commentary about why we must preserve
191 * %l5 and %l6 to preserve absolute correct semantics.
192 */
193 rdpr %wstate, %g2 ! Grab user mode wstate.
194 wrpr %g1, %cwp ! Get into the right window.
195 sll %g2, 3, %g2 ! NORMAL-->OTHER
196 wrpr %g0, 0x0, %canrestore ! Standard etrap stuff.
197
198 wrpr %g2, 0x0, %wstate ! This must be consistent.
199 wrpr %g0, 0x0, %otherwin ! We know this.
200 call set_pcontext ! Change contexts...
201 nop
202 rdpr %pstate, %l1 ! Prepare to change globals.
203 mov %g4, %o2 ! Setup args for
204 mov %g5, %o1 ! final call to mem_address_unaligned.
205 andn %l1, PSTATE_MM, %l1 ! We want to be in RMO
206
207 mov %g6, %o7 ! Stash away current.
208 wrpr %g0, 0x0, %tl ! Out of trap levels.
209 wrpr %l1, (PSTATE_IE | PSTATE_AG | PSTATE_RMO), %pstate
210 mov %o7, %g6 ! Get current back.
211 ldx [%g6 + TI_TASK], %g4 ! Finish it.
David S. Miller56fb4df2006-02-26 23:24:22 -0800[diff] [blame]212 LOAD_PER_CPU_BASE(%g1, %g2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]213 call mem_address_unaligned
214 add %sp, PTREGS_OFF, %o0
215
216 b,pt %xcc, rtrap
217 nop ! yes, the nop is correct
218spill_fixup_mna:
David S. Miller56fb4df2006-02-26 23:24:22 -0800[diff] [blame]219 TRAP_LOAD_THREAD_REG
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]220 ldx [%g6 + TI_FLAGS], %g1
221 andcc %g1, _TIF_32BIT, %g0
222 ldub [%g6 + TI_WSAVED], %g1
223 sll %g1, 3, %g3
224 add %g6, %g3, %g3
225 stx %sp, [%g3 + TI_RWIN_SPTRS]
226
227 sll %g1, 7, %g3
228 bne,pt %xcc, 1f
229 add %g6, %g3, %g3
230 stx %l0, [%g3 + TI_REG_WINDOW + 0x00]
231 stx %l1, [%g3 + TI_REG_WINDOW + 0x08]
232 stx %l2, [%g3 + TI_REG_WINDOW + 0x10]
233 stx %l3, [%g3 + TI_REG_WINDOW + 0x18]
234 stx %l4, [%g3 + TI_REG_WINDOW + 0x20]
235
236 stx %l5, [%g3 + TI_REG_WINDOW + 0x28]
237 stx %l6, [%g3 + TI_REG_WINDOW + 0x30]
238 stx %l7, [%g3 + TI_REG_WINDOW + 0x38]
239 stx %i0, [%g3 + TI_REG_WINDOW + 0x40]
240 stx %i1, [%g3 + TI_REG_WINDOW + 0x48]
241 stx %i2, [%g3 + TI_REG_WINDOW + 0x50]
242 stx %i3, [%g3 + TI_REG_WINDOW + 0x58]
243 stx %i4, [%g3 + TI_REG_WINDOW + 0x60]
244
245 stx %i5, [%g3 + TI_REG_WINDOW + 0x68]
246 stx %i6, [%g3 + TI_REG_WINDOW + 0x70]
247 stx %i7, [%g3 + TI_REG_WINDOW + 0x78]
248 b,pt %xcc, 2f
249 add %g1, 1, %g1
2501: std %l0, [%g3 + TI_REG_WINDOW + 0x00]
251 std %l2, [%g3 + TI_REG_WINDOW + 0x08]
252 std %l4, [%g3 + TI_REG_WINDOW + 0x10]
253
254 std %l6, [%g3 + TI_REG_WINDOW + 0x18]
255 std %i0, [%g3 + TI_REG_WINDOW + 0x20]
256 std %i2, [%g3 + TI_REG_WINDOW + 0x28]
257 std %i4, [%g3 + TI_REG_WINDOW + 0x30]
258 std %i6, [%g3 + TI_REG_WINDOW + 0x38]
259 add %g1, 1, %g1
2602: stb %g1, [%g6 + TI_WSAVED]
261 rdpr %tstate, %g1
262
263 andcc %g1, TSTATE_PRIV, %g0
264 saved
265 be,pn %xcc, window_mna_from_user_common
266 and %g1, TSTATE_CWP, %g1
267 retry
268window_mna_from_user_common:
269 wrpr %g1, %cwp
270 sethi %hi(109f), %g7
271 ba,pt %xcc, etrap
272109: or %g7, %lo(109b), %g7
273 mov %l4, %o2
274 mov %l5, %o1
275 call mem_address_unaligned
276 add %sp, PTREGS_OFF, %o0
277 ba,pt %xcc, rtrap
278 clr %l6
279
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]280 .globl winfix_dax, fill_fixup_dax, spill_fixup_dax
281winfix_dax:
282 andn %g3, 0x7f, %g3
283 add %g3, 0x74, %g3
284 wrpr %g3, %tnpc
285 done
286fill_fixup_dax:
David S. Miller56fb4df2006-02-26 23:24:22 -0800[diff] [blame]287 TRAP_LOAD_THREAD_REG
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]288 rdpr %tstate, %g1
289 andcc %g1, TSTATE_PRIV, %g0
290 be,pt %xcc, window_dax_from_user_common
291 and %g1, TSTATE_CWP, %g1
292
293 /* Please, see fill_fixup commentary about why we must preserve
294 * %l5 and %l6 to preserve absolute correct semantics.
295 */
296 rdpr %wstate, %g2 ! Grab user mode wstate.
297 wrpr %g1, %cwp ! Get into the right window.
298 sll %g2, 3, %g2 ! NORMAL-->OTHER
299 wrpr %g0, 0x0, %canrestore ! Standard etrap stuff.
300
301 wrpr %g2, 0x0, %wstate ! This must be consistent.
302 wrpr %g0, 0x0, %otherwin ! We know this.
303 call set_pcontext ! Change contexts...
304 nop
305 rdpr %pstate, %l1 ! Prepare to change globals.
306 mov %g4, %o1 ! Setup args for
David S. Miller6c52a962005-08-29 12:45:11 -0700[diff] [blame]307 mov %g5, %o2 ! final call to spitfire_data_access_exception.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]308 andn %l1, PSTATE_MM, %l1 ! We want to be in RMO
309
310 mov %g6, %o7 ! Stash away current.
311 wrpr %g0, 0x0, %tl ! Out of trap levels.
312 wrpr %l1, (PSTATE_IE | PSTATE_AG | PSTATE_RMO), %pstate
313 mov %o7, %g6 ! Get current back.
314 ldx [%g6 + TI_TASK], %g4 ! Finish it.
David S. Miller56fb4df2006-02-26 23:24:22 -0800[diff] [blame]315 LOAD_PER_CPU_BASE(%g1, %g2)
David S. Miller6c52a962005-08-29 12:45:11 -0700[diff] [blame]316 call spitfire_data_access_exception
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]317 add %sp, PTREGS_OFF, %o0
318
319 b,pt %xcc, rtrap
320 nop ! yes, the nop is correct
321spill_fixup_dax:
David S. Miller56fb4df2006-02-26 23:24:22 -0800[diff] [blame]322 TRAP_LOAD_THREAD_REG
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]323 ldx [%g6 + TI_FLAGS], %g1
324 andcc %g1, _TIF_32BIT, %g0
325 ldub [%g6 + TI_WSAVED], %g1
326 sll %g1, 3, %g3
327 add %g6, %g3, %g3
328 stx %sp, [%g3 + TI_RWIN_SPTRS]
329
330 sll %g1, 7, %g3
331 bne,pt %xcc, 1f
332 add %g6, %g3, %g3
333 stx %l0, [%g3 + TI_REG_WINDOW + 0x00]
334 stx %l1, [%g3 + TI_REG_WINDOW + 0x08]
335 stx %l2, [%g3 + TI_REG_WINDOW + 0x10]
336 stx %l3, [%g3 + TI_REG_WINDOW + 0x18]
337 stx %l4, [%g3 + TI_REG_WINDOW + 0x20]
338
339 stx %l5, [%g3 + TI_REG_WINDOW + 0x28]
340 stx %l6, [%g3 + TI_REG_WINDOW + 0x30]
341 stx %l7, [%g3 + TI_REG_WINDOW + 0x38]
342 stx %i0, [%g3 + TI_REG_WINDOW + 0x40]
343 stx %i1, [%g3 + TI_REG_WINDOW + 0x48]
344 stx %i2, [%g3 + TI_REG_WINDOW + 0x50]
345 stx %i3, [%g3 + TI_REG_WINDOW + 0x58]
346 stx %i4, [%g3 + TI_REG_WINDOW + 0x60]
347
348 stx %i5, [%g3 + TI_REG_WINDOW + 0x68]
349 stx %i6, [%g3 + TI_REG_WINDOW + 0x70]
350 stx %i7, [%g3 + TI_REG_WINDOW + 0x78]
351 b,pt %xcc, 2f
352 add %g1, 1, %g1
3531: std %l0, [%g3 + TI_REG_WINDOW + 0x00]
354 std %l2, [%g3 + TI_REG_WINDOW + 0x08]
355 std %l4, [%g3 + TI_REG_WINDOW + 0x10]
356
357 std %l6, [%g3 + TI_REG_WINDOW + 0x18]
358 std %i0, [%g3 + TI_REG_WINDOW + 0x20]
359 std %i2, [%g3 + TI_REG_WINDOW + 0x28]
360 std %i4, [%g3 + TI_REG_WINDOW + 0x30]
361 std %i6, [%g3 + TI_REG_WINDOW + 0x38]
362 add %g1, 1, %g1
3632: stb %g1, [%g6 + TI_WSAVED]
364 rdpr %tstate, %g1
365
366 andcc %g1, TSTATE_PRIV, %g0
367 saved
368 be,pn %xcc, window_dax_from_user_common
369 and %g1, TSTATE_CWP, %g1
370 retry
371window_dax_from_user_common:
372 wrpr %g1, %cwp
373 sethi %hi(109f), %g7
374 ba,pt %xcc, etrap
375109: or %g7, %lo(109b), %g7
376 mov %l4, %o1
377 mov %l5, %o2
David S. Miller6c52a962005-08-29 12:45:11 -0700[diff] [blame]378 call spitfire_data_access_exception
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]379 add %sp, PTREGS_OFF, %o0
380 ba,pt %xcc, rtrap
381 clr %l6