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Commit | Line | Data |
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88278ca2 | 1 | /* |
1da177e4 LT |
2 | * rtrap.S: Return from Sparc trap low-level code. |
3 | * | |
4 | * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) | |
5 | */ | |
6 | ||
7 | #include <asm/page.h> | |
8 | #include <asm/ptrace.h> | |
9 | #include <asm/psr.h> | |
10 | #include <asm/asi.h> | |
11 | #include <asm/smp.h> | |
12 | #include <asm/contregs.h> | |
13 | #include <asm/winmacro.h> | |
14 | #include <asm/asmmacro.h> | |
15 | #include <asm/thread_info.h> | |
16 | ||
17 | #define t_psr l0 | |
18 | #define t_pc l1 | |
19 | #define t_npc l2 | |
20 | #define t_wim l3 | |
21 | #define twin_tmp1 l4 | |
22 | #define glob_tmp g4 | |
23 | #define curptr g6 | |
24 | ||
25 | /* 7 WINDOW SPARC PATCH INSTRUCTIONS */ | |
26 | .globl rtrap_7win_patch1, rtrap_7win_patch2, rtrap_7win_patch3 | |
27 | .globl rtrap_7win_patch4, rtrap_7win_patch5 | |
28 | rtrap_7win_patch1: srl %t_wim, 0x6, %glob_tmp | |
29 | rtrap_7win_patch2: and %glob_tmp, 0x7f, %glob_tmp | |
30 | rtrap_7win_patch3: srl %g1, 7, %g2 | |
31 | rtrap_7win_patch4: srl %g2, 6, %g2 | |
32 | rtrap_7win_patch5: and %g1, 0x7f, %g1 | |
33 | /* END OF PATCH INSTRUCTIONS */ | |
34 | ||
35 | /* We need to check for a few things which are: | |
36 | * 1) The need to call schedule() because this | |
37 | * processes quantum is up. | |
38 | * 2) Pending signals for this process, if any | |
39 | * exist we need to call do_signal() to do | |
40 | * the needy. | |
41 | * | |
42 | * Else we just check if the rett would land us | |
43 | * in an invalid window, if so we need to grab | |
44 | * it off the user/kernel stack first. | |
45 | */ | |
46 | ||
47 | .globl ret_trap_entry, rtrap_patch1, rtrap_patch2 | |
48 | .globl rtrap_patch3, rtrap_patch4, rtrap_patch5 | |
49 | .globl ret_trap_lockless_ipi | |
50 | ret_trap_entry: | |
51 | ret_trap_lockless_ipi: | |
52 | andcc %t_psr, PSR_PS, %g0 | |
28e61036 | 53 | sethi %hi(PSR_SYSCALL), %g1 |
1da177e4 | 54 | be 1f |
28e61036 | 55 | andn %t_psr, %g1, %t_psr |
1da177e4 LT |
56 | |
57 | wr %t_psr, 0x0, %psr | |
58 | b ret_trap_kernel | |
59 | nop | |
60 | ||
61 | 1: | |
62 | ld [%curptr + TI_FLAGS], %g2 | |
63 | andcc %g2, (_TIF_NEED_RESCHED), %g0 | |
64 | be signal_p | |
65 | nop | |
66 | ||
67 | call schedule | |
68 | nop | |
69 | ||
70 | ld [%curptr + TI_FLAGS], %g2 | |
71 | signal_p: | |
2d7d5f05 | 72 | andcc %g2, (_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK), %g0 |
1da177e4 LT |
73 | bz,a ret_trap_continue |
74 | ld [%sp + STACKFRAME_SZ + PT_PSR], %t_psr | |
75 | ||
2d7d5f05 | 76 | mov %l5, %o1 |
1da177e4 | 77 | call do_signal |
2d7d5f05 | 78 | add %sp, STACKFRAME_SZ, %o0 ! pt_regs ptr |
1da177e4 LT |
79 | |
80 | /* Fall through. */ | |
81 | ld [%sp + STACKFRAME_SZ + PT_PSR], %t_psr | |
82 | clr %l6 | |
83 | ret_trap_continue: | |
28e61036 DM |
84 | sethi %hi(PSR_SYSCALL), %g1 |
85 | andn %t_psr, %g1, %t_psr | |
1da177e4 LT |
86 | wr %t_psr, 0x0, %psr |
87 | WRITE_PAUSE | |
88 | ||
89 | ld [%curptr + TI_W_SAVED], %twin_tmp1 | |
90 | orcc %g0, %twin_tmp1, %g0 | |
91 | be ret_trap_nobufwins | |
92 | nop | |
93 | ||
94 | wr %t_psr, PSR_ET, %psr | |
95 | WRITE_PAUSE | |
96 | ||
97 | mov 1, %o1 | |
98 | call try_to_clear_window_buffer | |
99 | add %sp, STACKFRAME_SZ, %o0 | |
100 | ||
101 | b signal_p | |
102 | ld [%curptr + TI_FLAGS], %g2 | |
103 | ||
104 | ret_trap_nobufwins: | |
105 | /* Load up the user's out registers so we can pull | |
106 | * a window from the stack, if necessary. | |
107 | */ | |
108 | LOAD_PT_INS(sp) | |
109 | ||
110 | /* If there are already live user windows in the | |
111 | * set we can return from trap safely. | |
112 | */ | |
113 | ld [%curptr + TI_UWINMASK], %twin_tmp1 | |
114 | orcc %g0, %twin_tmp1, %g0 | |
115 | bne ret_trap_userwins_ok | |
116 | nop | |
117 | ||
118 | /* Calculate new %wim, we have to pull a register | |
119 | * window from the users stack. | |
120 | */ | |
121 | ret_trap_pull_one_window: | |
122 | rd %wim, %t_wim | |
123 | sll %t_wim, 0x1, %twin_tmp1 | |
124 | rtrap_patch1: srl %t_wim, 0x7, %glob_tmp | |
125 | or %glob_tmp, %twin_tmp1, %glob_tmp | |
126 | rtrap_patch2: and %glob_tmp, 0xff, %glob_tmp | |
127 | ||
128 | wr %glob_tmp, 0x0, %wim | |
129 | ||
130 | /* Here comes the architecture specific | |
131 | * branch to the user stack checking routine | |
132 | * for return from traps. | |
133 | */ | |
134 | .globl rtrap_mmu_patchme | |
135 | rtrap_mmu_patchme: b sun4c_rett_stackchk | |
136 | andcc %fp, 0x7, %g0 | |
137 | ||
138 | ret_trap_userwins_ok: | |
139 | LOAD_PT_PRIV(sp, t_psr, t_pc, t_npc) | |
140 | or %t_pc, %t_npc, %g2 | |
141 | andcc %g2, 0x3, %g0 | |
8bf3028e | 142 | sethi %hi(PSR_SYSCALL), %g2 |
1da177e4 | 143 | be 1f |
28e61036 | 144 | andn %t_psr, %g2, %t_psr |
1da177e4 LT |
145 | |
146 | b ret_trap_unaligned_pc | |
147 | add %sp, STACKFRAME_SZ, %o0 | |
148 | ||
149 | 1: | |
150 | LOAD_PT_YREG(sp, g1) | |
151 | LOAD_PT_GLOBALS(sp) | |
152 | ||
153 | wr %t_psr, 0x0, %psr | |
154 | WRITE_PAUSE | |
155 | ||
156 | jmp %t_pc | |
157 | rett %t_npc | |
158 | ||
159 | ret_trap_unaligned_pc: | |
160 | ld [%sp + STACKFRAME_SZ + PT_PC], %o1 | |
161 | ld [%sp + STACKFRAME_SZ + PT_NPC], %o2 | |
162 | ld [%sp + STACKFRAME_SZ + PT_PSR], %o3 | |
163 | ||
164 | wr %t_wim, 0x0, %wim ! or else... | |
165 | ||
166 | wr %t_psr, PSR_ET, %psr | |
167 | WRITE_PAUSE | |
168 | ||
169 | call do_memaccess_unaligned | |
170 | nop | |
171 | ||
172 | b signal_p | |
173 | ld [%curptr + TI_FLAGS], %g2 | |
174 | ||
175 | ret_trap_kernel: | |
176 | /* Will the rett land us in the invalid window? */ | |
177 | mov 2, %g1 | |
178 | sll %g1, %t_psr, %g1 | |
179 | rtrap_patch3: srl %g1, 8, %g2 | |
180 | or %g1, %g2, %g1 | |
181 | rd %wim, %g2 | |
182 | andcc %g2, %g1, %g0 | |
183 | be 1f ! Nope, just return from the trap | |
184 | sll %g2, 0x1, %g1 | |
185 | ||
186 | /* We have to grab a window before returning. */ | |
187 | rtrap_patch4: srl %g2, 7, %g2 | |
188 | or %g1, %g2, %g1 | |
189 | rtrap_patch5: and %g1, 0xff, %g1 | |
190 | ||
191 | wr %g1, 0x0, %wim | |
192 | ||
193 | /* Grrr, make sure we load from the right %sp... */ | |
194 | LOAD_PT_ALL(sp, t_psr, t_pc, t_npc, g1) | |
195 | ||
196 | restore %g0, %g0, %g0 | |
197 | LOAD_WINDOW(sp) | |
198 | b 2f | |
199 | save %g0, %g0, %g0 | |
200 | ||
201 | /* Reload the entire frame in case this is from a | |
202 | * kernel system call or whatever... | |
203 | */ | |
204 | 1: | |
205 | LOAD_PT_ALL(sp, t_psr, t_pc, t_npc, g1) | |
206 | 2: | |
28e61036 DM |
207 | sethi %hi(PSR_SYSCALL), %twin_tmp1 |
208 | andn %t_psr, %twin_tmp1, %t_psr | |
1da177e4 LT |
209 | wr %t_psr, 0x0, %psr |
210 | WRITE_PAUSE | |
211 | ||
212 | jmp %t_pc | |
213 | rett %t_npc | |
214 | ||
215 | ret_trap_user_stack_is_bolixed: | |
216 | wr %t_wim, 0x0, %wim | |
217 | ||
218 | wr %t_psr, PSR_ET, %psr | |
219 | WRITE_PAUSE | |
220 | ||
221 | call window_ret_fault | |
222 | add %sp, STACKFRAME_SZ, %o0 | |
223 | ||
224 | b signal_p | |
225 | ld [%curptr + TI_FLAGS], %g2 | |
226 | ||
227 | ||
228 | .globl sun4c_rett_stackchk | |
229 | sun4c_rett_stackchk: | |
230 | be 1f | |
231 | and %fp, 0xfff, %g1 ! delay slot | |
232 | ||
233 | b ret_trap_user_stack_is_bolixed + 0x4 | |
234 | wr %t_wim, 0x0, %wim | |
235 | ||
236 | /* See if we have to check the sanity of one page or two */ | |
237 | 1: | |
238 | add %g1, 0x38, %g1 | |
239 | sra %fp, 29, %g2 | |
240 | add %g2, 0x1, %g2 | |
241 | andncc %g2, 0x1, %g0 | |
242 | be 1f | |
243 | andncc %g1, 0xff8, %g0 | |
244 | ||
245 | /* %sp is in vma hole, yuck */ | |
246 | b ret_trap_user_stack_is_bolixed + 0x4 | |
247 | wr %t_wim, 0x0, %wim | |
248 | ||
249 | 1: | |
250 | be sun4c_rett_onepage /* Only one page to check */ | |
251 | lda [%fp] ASI_PTE, %g2 | |
252 | ||
253 | sun4c_rett_twopages: | |
254 | add %fp, 0x38, %g1 | |
255 | sra %g1, 29, %g2 | |
256 | add %g2, 0x1, %g2 | |
257 | andncc %g2, 0x1, %g0 | |
258 | be 1f | |
259 | lda [%g1] ASI_PTE, %g2 | |
260 | ||
261 | /* Second page is in vma hole */ | |
262 | b ret_trap_user_stack_is_bolixed + 0x4 | |
263 | wr %t_wim, 0x0, %wim | |
264 | ||
265 | 1: | |
266 | srl %g2, 29, %g2 | |
267 | andcc %g2, 0x4, %g0 | |
268 | bne sun4c_rett_onepage | |
269 | lda [%fp] ASI_PTE, %g2 | |
270 | ||
271 | /* Second page has bad perms */ | |
272 | b ret_trap_user_stack_is_bolixed + 0x4 | |
273 | wr %t_wim, 0x0, %wim | |
274 | ||
275 | sun4c_rett_onepage: | |
276 | srl %g2, 29, %g2 | |
277 | andcc %g2, 0x4, %g0 | |
278 | bne,a 1f | |
279 | restore %g0, %g0, %g0 | |
280 | ||
281 | /* A page had bad page permissions, losing... */ | |
282 | b ret_trap_user_stack_is_bolixed + 0x4 | |
283 | wr %t_wim, 0x0, %wim | |
284 | ||
285 | /* Whee, things are ok, load the window and continue. */ | |
286 | 1: | |
287 | LOAD_WINDOW(sp) | |
288 | ||
289 | b ret_trap_userwins_ok | |
290 | save %g0, %g0, %g0 | |
291 | ||
292 | .globl srmmu_rett_stackchk | |
293 | srmmu_rett_stackchk: | |
294 | bne ret_trap_user_stack_is_bolixed | |
295 | sethi %hi(PAGE_OFFSET), %g1 | |
296 | cmp %g1, %fp | |
297 | bleu ret_trap_user_stack_is_bolixed | |
298 | mov AC_M_SFSR, %g1 | |
299 | lda [%g1] ASI_M_MMUREGS, %g0 | |
300 | ||
301 | lda [%g0] ASI_M_MMUREGS, %g1 | |
302 | or %g1, 0x2, %g1 | |
303 | sta %g1, [%g0] ASI_M_MMUREGS | |
304 | ||
305 | restore %g0, %g0, %g0 | |
306 | ||
307 | LOAD_WINDOW(sp) | |
308 | ||
309 | save %g0, %g0, %g0 | |
310 | ||
311 | andn %g1, 0x2, %g1 | |
312 | sta %g1, [%g0] ASI_M_MMUREGS | |
313 | ||
314 | mov AC_M_SFAR, %g2 | |
315 | lda [%g2] ASI_M_MMUREGS, %g2 | |
316 | ||
317 | mov AC_M_SFSR, %g1 | |
318 | lda [%g1] ASI_M_MMUREGS, %g1 | |
319 | andcc %g1, 0x2, %g0 | |
320 | be ret_trap_userwins_ok | |
321 | nop | |
322 | ||
323 | b,a ret_trap_user_stack_is_bolixed |