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: | |
5a157d5b | 72 | andcc %g2, _TIF_DO_NOTIFY_RESUME_MASK, %g0 |
1da177e4 LT |
73 | bz,a ret_trap_continue |
74 | ld [%sp + STACKFRAME_SZ + PT_PSR], %t_psr | |
75 | ||
5a157d5b | 76 | mov %g2, %o2 |
2d7d5f05 | 77 | mov %l5, %o1 |
5a157d5b | 78 | call do_notify_resume |
2d7d5f05 | 79 | add %sp, STACKFRAME_SZ, %o0 ! pt_regs ptr |
1da177e4 LT |
80 | |
81 | /* Fall through. */ | |
82 | ld [%sp + STACKFRAME_SZ + PT_PSR], %t_psr | |
83 | clr %l6 | |
84 | ret_trap_continue: | |
28e61036 DM |
85 | sethi %hi(PSR_SYSCALL), %g1 |
86 | andn %t_psr, %g1, %t_psr | |
1da177e4 LT |
87 | wr %t_psr, 0x0, %psr |
88 | WRITE_PAUSE | |
89 | ||
90 | ld [%curptr + TI_W_SAVED], %twin_tmp1 | |
91 | orcc %g0, %twin_tmp1, %g0 | |
92 | be ret_trap_nobufwins | |
93 | nop | |
94 | ||
95 | wr %t_psr, PSR_ET, %psr | |
96 | WRITE_PAUSE | |
97 | ||
98 | mov 1, %o1 | |
99 | call try_to_clear_window_buffer | |
100 | add %sp, STACKFRAME_SZ, %o0 | |
101 | ||
102 | b signal_p | |
103 | ld [%curptr + TI_FLAGS], %g2 | |
104 | ||
105 | ret_trap_nobufwins: | |
106 | /* Load up the user's out registers so we can pull | |
107 | * a window from the stack, if necessary. | |
108 | */ | |
109 | LOAD_PT_INS(sp) | |
110 | ||
111 | /* If there are already live user windows in the | |
112 | * set we can return from trap safely. | |
113 | */ | |
114 | ld [%curptr + TI_UWINMASK], %twin_tmp1 | |
115 | orcc %g0, %twin_tmp1, %g0 | |
116 | bne ret_trap_userwins_ok | |
117 | nop | |
118 | ||
119 | /* Calculate new %wim, we have to pull a register | |
120 | * window from the users stack. | |
121 | */ | |
122 | ret_trap_pull_one_window: | |
123 | rd %wim, %t_wim | |
124 | sll %t_wim, 0x1, %twin_tmp1 | |
125 | rtrap_patch1: srl %t_wim, 0x7, %glob_tmp | |
126 | or %glob_tmp, %twin_tmp1, %glob_tmp | |
127 | rtrap_patch2: and %glob_tmp, 0xff, %glob_tmp | |
128 | ||
129 | wr %glob_tmp, 0x0, %wim | |
130 | ||
131 | /* Here comes the architecture specific | |
132 | * branch to the user stack checking routine | |
133 | * for return from traps. | |
134 | */ | |
135 | .globl rtrap_mmu_patchme | |
136 | rtrap_mmu_patchme: b sun4c_rett_stackchk | |
137 | andcc %fp, 0x7, %g0 | |
138 | ||
139 | ret_trap_userwins_ok: | |
140 | LOAD_PT_PRIV(sp, t_psr, t_pc, t_npc) | |
141 | or %t_pc, %t_npc, %g2 | |
142 | andcc %g2, 0x3, %g0 | |
8bf3028e | 143 | sethi %hi(PSR_SYSCALL), %g2 |
1da177e4 | 144 | be 1f |
28e61036 | 145 | andn %t_psr, %g2, %t_psr |
1da177e4 LT |
146 | |
147 | b ret_trap_unaligned_pc | |
148 | add %sp, STACKFRAME_SZ, %o0 | |
149 | ||
150 | 1: | |
151 | LOAD_PT_YREG(sp, g1) | |
152 | LOAD_PT_GLOBALS(sp) | |
153 | ||
154 | wr %t_psr, 0x0, %psr | |
155 | WRITE_PAUSE | |
156 | ||
157 | jmp %t_pc | |
158 | rett %t_npc | |
159 | ||
160 | ret_trap_unaligned_pc: | |
161 | ld [%sp + STACKFRAME_SZ + PT_PC], %o1 | |
162 | ld [%sp + STACKFRAME_SZ + PT_NPC], %o2 | |
163 | ld [%sp + STACKFRAME_SZ + PT_PSR], %o3 | |
164 | ||
165 | wr %t_wim, 0x0, %wim ! or else... | |
166 | ||
167 | wr %t_psr, PSR_ET, %psr | |
168 | WRITE_PAUSE | |
169 | ||
170 | call do_memaccess_unaligned | |
171 | nop | |
172 | ||
173 | b signal_p | |
174 | ld [%curptr + TI_FLAGS], %g2 | |
175 | ||
176 | ret_trap_kernel: | |
177 | /* Will the rett land us in the invalid window? */ | |
178 | mov 2, %g1 | |
179 | sll %g1, %t_psr, %g1 | |
180 | rtrap_patch3: srl %g1, 8, %g2 | |
181 | or %g1, %g2, %g1 | |
182 | rd %wim, %g2 | |
183 | andcc %g2, %g1, %g0 | |
184 | be 1f ! Nope, just return from the trap | |
185 | sll %g2, 0x1, %g1 | |
186 | ||
187 | /* We have to grab a window before returning. */ | |
188 | rtrap_patch4: srl %g2, 7, %g2 | |
189 | or %g1, %g2, %g1 | |
190 | rtrap_patch5: and %g1, 0xff, %g1 | |
191 | ||
192 | wr %g1, 0x0, %wim | |
193 | ||
194 | /* Grrr, make sure we load from the right %sp... */ | |
195 | LOAD_PT_ALL(sp, t_psr, t_pc, t_npc, g1) | |
196 | ||
197 | restore %g0, %g0, %g0 | |
198 | LOAD_WINDOW(sp) | |
199 | b 2f | |
200 | save %g0, %g0, %g0 | |
201 | ||
202 | /* Reload the entire frame in case this is from a | |
203 | * kernel system call or whatever... | |
204 | */ | |
205 | 1: | |
206 | LOAD_PT_ALL(sp, t_psr, t_pc, t_npc, g1) | |
207 | 2: | |
28e61036 DM |
208 | sethi %hi(PSR_SYSCALL), %twin_tmp1 |
209 | andn %t_psr, %twin_tmp1, %t_psr | |
1da177e4 LT |
210 | wr %t_psr, 0x0, %psr |
211 | WRITE_PAUSE | |
212 | ||
213 | jmp %t_pc | |
214 | rett %t_npc | |
215 | ||
216 | ret_trap_user_stack_is_bolixed: | |
217 | wr %t_wim, 0x0, %wim | |
218 | ||
219 | wr %t_psr, PSR_ET, %psr | |
220 | WRITE_PAUSE | |
221 | ||
222 | call window_ret_fault | |
223 | add %sp, STACKFRAME_SZ, %o0 | |
224 | ||
225 | b signal_p | |
226 | ld [%curptr + TI_FLAGS], %g2 | |
227 | ||
1da177e4 LT |
228 | sun4c_rett_stackchk: |
229 | be 1f | |
230 | and %fp, 0xfff, %g1 ! delay slot | |
231 | ||
232 | b ret_trap_user_stack_is_bolixed + 0x4 | |
233 | wr %t_wim, 0x0, %wim | |
234 | ||
235 | /* See if we have to check the sanity of one page or two */ | |
236 | 1: | |
237 | add %g1, 0x38, %g1 | |
238 | sra %fp, 29, %g2 | |
239 | add %g2, 0x1, %g2 | |
240 | andncc %g2, 0x1, %g0 | |
241 | be 1f | |
242 | andncc %g1, 0xff8, %g0 | |
243 | ||
244 | /* %sp is in vma hole, yuck */ | |
245 | b ret_trap_user_stack_is_bolixed + 0x4 | |
246 | wr %t_wim, 0x0, %wim | |
247 | ||
248 | 1: | |
249 | be sun4c_rett_onepage /* Only one page to check */ | |
250 | lda [%fp] ASI_PTE, %g2 | |
251 | ||
252 | sun4c_rett_twopages: | |
253 | add %fp, 0x38, %g1 | |
254 | sra %g1, 29, %g2 | |
255 | add %g2, 0x1, %g2 | |
256 | andncc %g2, 0x1, %g0 | |
257 | be 1f | |
258 | lda [%g1] ASI_PTE, %g2 | |
259 | ||
260 | /* Second page is in vma hole */ | |
261 | b ret_trap_user_stack_is_bolixed + 0x4 | |
262 | wr %t_wim, 0x0, %wim | |
263 | ||
264 | 1: | |
265 | srl %g2, 29, %g2 | |
266 | andcc %g2, 0x4, %g0 | |
267 | bne sun4c_rett_onepage | |
268 | lda [%fp] ASI_PTE, %g2 | |
269 | ||
270 | /* Second page has bad perms */ | |
271 | b ret_trap_user_stack_is_bolixed + 0x4 | |
272 | wr %t_wim, 0x0, %wim | |
273 | ||
274 | sun4c_rett_onepage: | |
275 | srl %g2, 29, %g2 | |
276 | andcc %g2, 0x4, %g0 | |
277 | bne,a 1f | |
278 | restore %g0, %g0, %g0 | |
279 | ||
280 | /* A page had bad page permissions, losing... */ | |
281 | b ret_trap_user_stack_is_bolixed + 0x4 | |
282 | wr %t_wim, 0x0, %wim | |
283 | ||
284 | /* Whee, things are ok, load the window and continue. */ | |
285 | 1: | |
286 | LOAD_WINDOW(sp) | |
287 | ||
288 | b ret_trap_userwins_ok | |
289 | save %g0, %g0, %g0 | |
290 | ||
291 | .globl srmmu_rett_stackchk | |
292 | srmmu_rett_stackchk: | |
293 | bne ret_trap_user_stack_is_bolixed | |
294 | sethi %hi(PAGE_OFFSET), %g1 | |
295 | cmp %g1, %fp | |
296 | bleu ret_trap_user_stack_is_bolixed | |
297 | mov AC_M_SFSR, %g1 | |
298 | lda [%g1] ASI_M_MMUREGS, %g0 | |
299 | ||
300 | lda [%g0] ASI_M_MMUREGS, %g1 | |
301 | or %g1, 0x2, %g1 | |
302 | sta %g1, [%g0] ASI_M_MMUREGS | |
303 | ||
304 | restore %g0, %g0, %g0 | |
305 | ||
306 | LOAD_WINDOW(sp) | |
307 | ||
308 | save %g0, %g0, %g0 | |
309 | ||
310 | andn %g1, 0x2, %g1 | |
311 | sta %g1, [%g0] ASI_M_MMUREGS | |
312 | ||
313 | mov AC_M_SFAR, %g2 | |
314 | lda [%g2] ASI_M_MMUREGS, %g2 | |
315 | ||
316 | mov AC_M_SFSR, %g1 | |
317 | lda [%g1] ASI_M_MMUREGS, %g1 | |
318 | andcc %g1, 0x2, %g0 | |
319 | be ret_trap_userwins_ok | |
320 | nop | |
321 | ||
322 | b,a ret_trap_user_stack_is_bolixed |