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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
88278ca2 | 2 | /* |
1da177e4 LT |
3 | * rtrap.S: Return from Sparc trap low-level code. |
4 | * | |
5 | * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) | |
6 | */ | |
7 | ||
8 | #include <asm/page.h> | |
9 | #include <asm/ptrace.h> | |
10 | #include <asm/psr.h> | |
11 | #include <asm/asi.h> | |
12 | #include <asm/smp.h> | |
13 | #include <asm/contregs.h> | |
14 | #include <asm/winmacro.h> | |
15 | #include <asm/asmmacro.h> | |
16 | #include <asm/thread_info.h> | |
17 | ||
18 | #define t_psr l0 | |
19 | #define t_pc l1 | |
20 | #define t_npc l2 | |
21 | #define t_wim l3 | |
22 | #define twin_tmp1 l4 | |
23 | #define glob_tmp g4 | |
24 | #define curptr g6 | |
25 | ||
26 | /* 7 WINDOW SPARC PATCH INSTRUCTIONS */ | |
27 | .globl rtrap_7win_patch1, rtrap_7win_patch2, rtrap_7win_patch3 | |
28 | .globl rtrap_7win_patch4, rtrap_7win_patch5 | |
29 | rtrap_7win_patch1: srl %t_wim, 0x6, %glob_tmp | |
30 | rtrap_7win_patch2: and %glob_tmp, 0x7f, %glob_tmp | |
31 | rtrap_7win_patch3: srl %g1, 7, %g2 | |
32 | rtrap_7win_patch4: srl %g2, 6, %g2 | |
33 | rtrap_7win_patch5: and %g1, 0x7f, %g1 | |
34 | /* END OF PATCH INSTRUCTIONS */ | |
35 | ||
36 | /* We need to check for a few things which are: | |
37 | * 1) The need to call schedule() because this | |
38 | * processes quantum is up. | |
39 | * 2) Pending signals for this process, if any | |
40 | * exist we need to call do_signal() to do | |
41 | * the needy. | |
42 | * | |
43 | * Else we just check if the rett would land us | |
44 | * in an invalid window, if so we need to grab | |
45 | * it off the user/kernel stack first. | |
46 | */ | |
47 | ||
48 | .globl ret_trap_entry, rtrap_patch1, rtrap_patch2 | |
49 | .globl rtrap_patch3, rtrap_patch4, rtrap_patch5 | |
50 | .globl ret_trap_lockless_ipi | |
51 | ret_trap_entry: | |
52 | ret_trap_lockless_ipi: | |
53 | andcc %t_psr, PSR_PS, %g0 | |
28e61036 | 54 | sethi %hi(PSR_SYSCALL), %g1 |
1da177e4 | 55 | be 1f |
28e61036 | 56 | andn %t_psr, %g1, %t_psr |
1da177e4 LT |
57 | |
58 | wr %t_psr, 0x0, %psr | |
59 | b ret_trap_kernel | |
60 | nop | |
61 | ||
62 | 1: | |
63 | ld [%curptr + TI_FLAGS], %g2 | |
64 | andcc %g2, (_TIF_NEED_RESCHED), %g0 | |
65 | be signal_p | |
66 | nop | |
67 | ||
68 | call schedule | |
69 | nop | |
70 | ||
71 | ld [%curptr + TI_FLAGS], %g2 | |
72 | signal_p: | |
5a157d5b | 73 | andcc %g2, _TIF_DO_NOTIFY_RESUME_MASK, %g0 |
1da177e4 LT |
74 | bz,a ret_trap_continue |
75 | ld [%sp + STACKFRAME_SZ + PT_PSR], %t_psr | |
76 | ||
5a157d5b | 77 | mov %g2, %o2 |
2d7d5f05 | 78 | mov %l5, %o1 |
5a157d5b | 79 | call do_notify_resume |
2d7d5f05 | 80 | add %sp, STACKFRAME_SZ, %o0 ! pt_regs ptr |
1da177e4 | 81 | |
caebf910 AV |
82 | b signal_p |
83 | ld [%curptr + TI_FLAGS], %g2 | |
84 | ||
1da177e4 | 85 | ret_trap_continue: |
28e61036 DM |
86 | sethi %hi(PSR_SYSCALL), %g1 |
87 | andn %t_psr, %g1, %t_psr | |
1da177e4 LT |
88 | wr %t_psr, 0x0, %psr |
89 | WRITE_PAUSE | |
90 | ||
91 | ld [%curptr + TI_W_SAVED], %twin_tmp1 | |
92 | orcc %g0, %twin_tmp1, %g0 | |
93 | be ret_trap_nobufwins | |
94 | nop | |
95 | ||
96 | wr %t_psr, PSR_ET, %psr | |
97 | WRITE_PAUSE | |
98 | ||
99 | mov 1, %o1 | |
100 | call try_to_clear_window_buffer | |
101 | add %sp, STACKFRAME_SZ, %o0 | |
102 | ||
103 | b signal_p | |
104 | ld [%curptr + TI_FLAGS], %g2 | |
105 | ||
106 | ret_trap_nobufwins: | |
107 | /* Load up the user's out registers so we can pull | |
108 | * a window from the stack, if necessary. | |
109 | */ | |
110 | LOAD_PT_INS(sp) | |
111 | ||
112 | /* If there are already live user windows in the | |
113 | * set we can return from trap safely. | |
114 | */ | |
115 | ld [%curptr + TI_UWINMASK], %twin_tmp1 | |
116 | orcc %g0, %twin_tmp1, %g0 | |
117 | bne ret_trap_userwins_ok | |
118 | nop | |
119 | ||
120 | /* Calculate new %wim, we have to pull a register | |
121 | * window from the users stack. | |
122 | */ | |
123 | ret_trap_pull_one_window: | |
124 | rd %wim, %t_wim | |
125 | sll %t_wim, 0x1, %twin_tmp1 | |
126 | rtrap_patch1: srl %t_wim, 0x7, %glob_tmp | |
127 | or %glob_tmp, %twin_tmp1, %glob_tmp | |
128 | rtrap_patch2: and %glob_tmp, 0xff, %glob_tmp | |
129 | ||
130 | wr %glob_tmp, 0x0, %wim | |
131 | ||
ef136bc9 SR |
132 | /* Here comes the architecture specific |
133 | * branch to the user stack checking routine | |
134 | * for return from traps. | |
135 | */ | |
136 | b srmmu_rett_stackchk | |
137 | andcc %fp, 0x7, %g0 | |
1da177e4 LT |
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 | .globl srmmu_rett_stackchk |
229 | srmmu_rett_stackchk: | |
230 | bne ret_trap_user_stack_is_bolixed | |
231 | sethi %hi(PAGE_OFFSET), %g1 | |
232 | cmp %g1, %fp | |
233 | bleu ret_trap_user_stack_is_bolixed | |
234 | mov AC_M_SFSR, %g1 | |
1ec8cf62 SR |
235 | LEON_PI(lda [%g1] ASI_LEON_MMUREGS, %g0) |
236 | SUN_PI_(lda [%g1] ASI_M_MMUREGS, %g0) | |
1da177e4 | 237 | |
1ec8cf62 SR |
238 | LEON_PI(lda [%g0] ASI_LEON_MMUREGS, %g1) |
239 | SUN_PI_(lda [%g0] ASI_M_MMUREGS, %g1) | |
1da177e4 | 240 | or %g1, 0x2, %g1 |
1ec8cf62 SR |
241 | LEON_PI(sta %g1, [%g0] ASI_LEON_MMUREGS) |
242 | SUN_PI_(sta %g1, [%g0] ASI_M_MMUREGS) | |
1da177e4 LT |
243 | |
244 | restore %g0, %g0, %g0 | |
245 | ||
246 | LOAD_WINDOW(sp) | |
247 | ||
248 | save %g0, %g0, %g0 | |
249 | ||
250 | andn %g1, 0x2, %g1 | |
1ec8cf62 SR |
251 | LEON_PI(sta %g1, [%g0] ASI_LEON_MMUREGS) |
252 | SUN_PI_(sta %g1, [%g0] ASI_M_MMUREGS) | |
1da177e4 LT |
253 | |
254 | mov AC_M_SFAR, %g2 | |
1ec8cf62 SR |
255 | LEON_PI(lda [%g2] ASI_LEON_MMUREGS, %g2) |
256 | SUN_PI_(lda [%g2] ASI_M_MMUREGS, %g2) | |
1da177e4 LT |
257 | |
258 | mov AC_M_SFSR, %g1 | |
1ec8cf62 SR |
259 | LEON_PI(lda [%g1] ASI_LEON_MMUREGS, %g1) |
260 | SUN_PI_(lda [%g1] ASI_M_MMUREGS, %g1) | |
1da177e4 LT |
261 | andcc %g1, 0x2, %g0 |
262 | be ret_trap_userwins_ok | |
263 | nop | |
264 | ||
265 | b,a ret_trap_user_stack_is_bolixed |