1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* 2 /*
3 * wof.S: Sparc window overflow handler. 3 * wof.S: Sparc window overflow handler.
4 * 4 *
5 * Copyright (C) 1995 David S. Miller (davem@c 5 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
6 */ 6 */
7 7
8 #include <asm/contregs.h> 8 #include <asm/contregs.h>
9 #include <asm/page.h> 9 #include <asm/page.h>
10 #include <asm/ptrace.h> 10 #include <asm/ptrace.h>
11 #include <asm/psr.h> 11 #include <asm/psr.h>
12 #include <asm/smp.h> 12 #include <asm/smp.h>
13 #include <asm/asi.h> 13 #include <asm/asi.h>
14 #include <asm/winmacro.h> 14 #include <asm/winmacro.h>
15 #include <asm/asmmacro.h> 15 #include <asm/asmmacro.h>
16 #include <asm/thread_info.h> 16 #include <asm/thread_info.h>
17 17
18 /* WARNING: This routine is hairy and _very_ c 18 /* WARNING: This routine is hairy and _very_ complicated, but it
19 * must be as fast as possible as it 19 * must be as fast as possible as it handles the allocation
20 * of register windows to the user an 20 * of register windows to the user and kernel. If you touch
21 * this code be _very_ careful as man 21 * this code be _very_ careful as many other pieces of the
22 * kernel depend upon how this code b 22 * kernel depend upon how this code behaves. You have been
23 * duly warned... 23 * duly warned...
24 */ 24 */
25 25
26 /* We define macro's for registers which have 26 /* We define macro's for registers which have a fixed
27 * meaning throughout this entire routine. Th 27 * meaning throughout this entire routine. The 'T' in
28 * the comments mean that the register can onl 28 * the comments mean that the register can only be
29 * accessed when in the 'trap' window, 'G' mea 29 * accessed when in the 'trap' window, 'G' means
30 * accessible in any window. Do not change th 30 * accessible in any window. Do not change these registers
31 * after they have been set, until you are rea 31 * after they have been set, until you are ready to return
32 * from the trap. 32 * from the trap.
33 */ 33 */
34 #define t_psr l0 /* %psr at trap time 34 #define t_psr l0 /* %psr at trap time T */
35 #define t_pc l1 /* PC for trap return 35 #define t_pc l1 /* PC for trap return T */
36 #define t_npc l2 /* NPC for trap return 36 #define t_npc l2 /* NPC for trap return T */
37 #define t_wim l3 /* %wim at trap time 37 #define t_wim l3 /* %wim at trap time T */
38 #define saved_g5 l5 /* Global save register 38 #define saved_g5 l5 /* Global save register T */
39 #define saved_g6 l6 /* Global save register 39 #define saved_g6 l6 /* Global save register T */
40 #define curptr g6 /* Gets set to 'current 40 #define curptr g6 /* Gets set to 'current' then stays G */
41 41
42 /* Now registers whose values can change withi 42 /* Now registers whose values can change within the handler. */
43 #define twin_tmp l4 /* Temp reg, only usabl 43 #define twin_tmp l4 /* Temp reg, only usable in trap window T */
44 #define glob_tmp g5 /* Global temporary reg 44 #define glob_tmp g5 /* Global temporary reg, usable anywhere G */
45 45
46 .text 46 .text
47 .align 4 47 .align 4
48 /* BEGINNING OF PATCH INSTRUCTIONS */ 48 /* BEGINNING OF PATCH INSTRUCTIONS */
49 /* On a 7-window Sparc the boot code p 49 /* On a 7-window Sparc the boot code patches spnwin_*
50 * instructions with the following one 50 * instructions with the following ones.
51 */ 51 */
52 .globl spnwin_patch1_7win, spnwin_pat 52 .globl spnwin_patch1_7win, spnwin_patch2_7win, spnwin_patch3_7win
53 spnwin_patch1_7win: sll %t_wim, 6, %gl 53 spnwin_patch1_7win: sll %t_wim, 6, %glob_tmp
54 spnwin_patch2_7win: and %glob_tmp, 0x7 54 spnwin_patch2_7win: and %glob_tmp, 0x7f, %glob_tmp
55 spnwin_patch3_7win: and %twin_tmp, 0x7 55 spnwin_patch3_7win: and %twin_tmp, 0x7f, %twin_tmp
56 /* END OF PATCH INSTRUCTIONS */ 56 /* END OF PATCH INSTRUCTIONS */
57 57
58 /* The trap entry point has done the f 58 /* The trap entry point has done the following:
59 * 59 *
60 * rd %psr, %l0 60 * rd %psr, %l0
61 * rd %wim, %l3 61 * rd %wim, %l3
62 * b spill_window_entry 62 * b spill_window_entry
63 * andcc %l0, PSR_PS, %g0 63 * andcc %l0, PSR_PS, %g0
64 */ 64 */
65 65
66 /* Datum current_thread_info->uwinmask 66 /* Datum current_thread_info->uwinmask contains at all times a bitmask
67 * where if any user windows are activ 67 * where if any user windows are active, at least one bit will
68 * be set in to mask. If no user wind 68 * be set in to mask. If no user windows are active, the bitmask
69 * will be all zeroes. 69 * will be all zeroes.
70 */ 70 */
71 .globl spill_window_entry 71 .globl spill_window_entry
72 .globl spnwin_patch1, spnwin_patch2, 72 .globl spnwin_patch1, spnwin_patch2, spnwin_patch3
73 spill_window_entry: 73 spill_window_entry:
74 /* LOCATION: Trap Window */ 74 /* LOCATION: Trap Window */
75 75
76 mov %g5, %saved_g5 ! save 76 mov %g5, %saved_g5 ! save away global temp register
77 mov %g6, %saved_g6 ! save 77 mov %g6, %saved_g6 ! save away 'current' ptr register
78 78
79 /* Compute what the new %wim will be i 79 /* Compute what the new %wim will be if we save the
80 * window properly in this trap handle 80 * window properly in this trap handler.
81 * 81 *
82 * newwim = ((%wim>>1) | (%wim<<(nwind 82 * newwim = ((%wim>>1) | (%wim<<(nwindows - 1)));
83 */ 83 */
84 srl %t_wim, 0x1, %twin_tmp 84 srl %t_wim, 0x1, %twin_tmp
85 spnwin_patch1: sll %t_wim, 7, %glob_tmp 85 spnwin_patch1: sll %t_wim, 7, %glob_tmp
86 or %glob_tmp, %twin_tmp, 86 or %glob_tmp, %twin_tmp, %glob_tmp
87 spnwin_patch2: and %glob_tmp, 0xff, %glob 87 spnwin_patch2: and %glob_tmp, 0xff, %glob_tmp
88 88
89 /* The trap entry point has set the co 89 /* The trap entry point has set the condition codes
90 * up for us to see if this is from us 90 * up for us to see if this is from user or kernel.
91 * Get the load of 'curptr' out of the 91 * Get the load of 'curptr' out of the way.
92 */ 92 */
93 LOAD_CURRENT(curptr, twin_tmp) 93 LOAD_CURRENT(curptr, twin_tmp)
94 94
95 andcc %t_psr, PSR_PS, %g0 95 andcc %t_psr, PSR_PS, %g0
96 be,a spwin_fromuser 96 be,a spwin_fromuser ! all user wins, branch
97 save %g0, %g0, %g0 97 save %g0, %g0, %g0 ! Go where saving will occur
98 98
99 /* See if any user windows are active 99 /* See if any user windows are active in the set. */
100 ld [%curptr + TI_UWINMASK], %twin 100 ld [%curptr + TI_UWINMASK], %twin_tmp ! grab win mask
101 orcc %g0, %twin_tmp, %g0 101 orcc %g0, %twin_tmp, %g0 ! check for set bits
102 bne spwin_exist_uwins 102 bne spwin_exist_uwins ! yep, there are some
103 andn %twin_tmp, %glob_tmp, %twin_tm 103 andn %twin_tmp, %glob_tmp, %twin_tmp ! compute new uwinmask
104 104
105 /* Save into the window which must be 105 /* Save into the window which must be saved and do it.
106 * Basically if we are here, this mean 106 * Basically if we are here, this means that we trapped
107 * from kernel mode with only kernel w 107 * from kernel mode with only kernel windows in the register
108 * file. 108 * file.
109 */ 109 */
110 save %g0, %g0, %g0 ! save 110 save %g0, %g0, %g0 ! save into the window to stash away
111 wr %glob_tmp, 0x0, %wim ! set 111 wr %glob_tmp, 0x0, %wim ! set new %wim, this is safe now
112 112
113 spwin_no_userwins_from_kernel: 113 spwin_no_userwins_from_kernel:
114 /* LOCATION: Window to be saved */ 114 /* LOCATION: Window to be saved */
115 115
116 STORE_WINDOW(sp) ! stas 116 STORE_WINDOW(sp) ! stash the window
117 restore %g0, %g0, %g0 ! go b 117 restore %g0, %g0, %g0 ! go back into trap window
118 118
119 /* LOCATION: Trap window */ 119 /* LOCATION: Trap window */
120 mov %saved_g5, %g5 ! rest 120 mov %saved_g5, %g5 ! restore %glob_tmp
121 mov %saved_g6, %g6 ! rest 121 mov %saved_g6, %g6 ! restore %curptr
122 wr %t_psr, 0x0, %psr ! rest 122 wr %t_psr, 0x0, %psr ! restore condition codes in %psr
123 WRITE_PAUSE ! wast 123 WRITE_PAUSE ! waste some time
124 jmp %t_pc ! Retu 124 jmp %t_pc ! Return from trap
125 rett %t_npc ! we a 125 rett %t_npc ! we are done
126 126
127 spwin_exist_uwins: 127 spwin_exist_uwins:
128 /* LOCATION: Trap window */ 128 /* LOCATION: Trap window */
129 129
130 /* Wow, user windows have to be dealt 130 /* Wow, user windows have to be dealt with, this is dirty
131 * and messy as all hell. And difficu 131 * and messy as all hell. And difficult to follow if you
132 * are approaching the infamous regist 132 * are approaching the infamous register window trap handling
133 * problem for the first time. DON'T L 133 * problem for the first time. DON'T LOOK!
134 * 134 *
135 * Note that how the execution path wo 135 * Note that how the execution path works out, the new %wim
136 * will be left for us in the global t 136 * will be left for us in the global temporary register,
137 * %glob_tmp. We cannot set the new % 137 * %glob_tmp. We cannot set the new %wim first because we
138 * need to save into the appropriate w 138 * need to save into the appropriate window without inducing
139 * a trap (traps are off, we'd get a w 139 * a trap (traps are off, we'd get a watchdog wheee)...
140 * But first, store the new user windo 140 * But first, store the new user window mask calculated
141 * above. 141 * above.
142 */ 142 */
143 st %twin_tmp, [%curptr + TI_UWINM 143 st %twin_tmp, [%curptr + TI_UWINMASK]
144 save %g0, %g0, %g0 ! Go t 144 save %g0, %g0, %g0 ! Go to where the saving will occur
145 145
146 spwin_fromuser: 146 spwin_fromuser:
147 /* LOCATION: Window to be saved */ 147 /* LOCATION: Window to be saved */
148 wr %glob_tmp, 0x0, %wim ! Now 148 wr %glob_tmp, 0x0, %wim ! Now it is safe to set new %wim
149 149
150 /* LOCATION: Window to be saved */ 150 /* LOCATION: Window to be saved */
151 151
152 /* This instruction branches to a rout 152 /* This instruction branches to a routine which will check
153 * to validity of the users stack poin 153 * to validity of the users stack pointer by whatever means
154 * are necessary. This means that thi 154 * are necessary. This means that this is architecture
155 * specific and thus this branch instr 155 * specific and thus this branch instruction will need to
156 * be patched at boot time once the ma 156 * be patched at boot time once the machine type is known.
157 * This routine _shall not_ touch %cur 157 * This routine _shall not_ touch %curptr under any
158 * circumstances whatsoever! It will 158 * circumstances whatsoever! It will branch back to the
159 * label 'spwin_good_ustack' if the st 159 * label 'spwin_good_ustack' if the stack is ok but still
160 * needs to be dumped (SRMMU for insta 160 * needs to be dumped (SRMMU for instance will not need to
161 * do this) or 'spwin_finish_up' if th 161 * do this) or 'spwin_finish_up' if the stack is ok and the
162 * registers have already been saved. 162 * registers have already been saved. If the stack is found
163 * to be bogus for some reason the rou 163 * to be bogus for some reason the routine shall branch to
164 * the label 'spwin_user_stack_is_boli 164 * the label 'spwin_user_stack_is_bolixed' which will take
165 * care of things at that point. 165 * care of things at that point.
166 */ 166 */
167 b spwin_srmmu_stackchk 167 b spwin_srmmu_stackchk
168 andcc %sp, 0x7, %g0 168 andcc %sp, 0x7, %g0
169 169
170 spwin_good_ustack: 170 spwin_good_ustack:
171 /* LOCATION: Window to be saved */ 171 /* LOCATION: Window to be saved */
172 172
173 /* The users stack is ok and we can sa 173 /* The users stack is ok and we can safely save it at
174 * %sp. 174 * %sp.
175 */ 175 */
176 STORE_WINDOW(sp) 176 STORE_WINDOW(sp)
177 177
178 spwin_finish_up: 178 spwin_finish_up:
179 restore %g0, %g0, %g0 /* Bac 179 restore %g0, %g0, %g0 /* Back to trap window. */
180 180
181 /* LOCATION: Trap window */ 181 /* LOCATION: Trap window */
182 182
183 /* We have spilled successfully, and w 183 /* We have spilled successfully, and we have properly stored
184 * the appropriate window onto the sta 184 * the appropriate window onto the stack.
185 */ 185 */
186 186
187 /* Restore saved globals */ 187 /* Restore saved globals */
188 mov %saved_g5, %g5 188 mov %saved_g5, %g5
189 mov %saved_g6, %g6 189 mov %saved_g6, %g6
190 190
191 wr %t_psr, 0x0, %psr 191 wr %t_psr, 0x0, %psr
192 WRITE_PAUSE 192 WRITE_PAUSE
193 jmp %t_pc 193 jmp %t_pc
194 rett %t_npc 194 rett %t_npc
195 195
196 spwin_user_stack_is_bolixed: 196 spwin_user_stack_is_bolixed:
197 /* LOCATION: Window to be saved */ 197 /* LOCATION: Window to be saved */
198 198
199 /* Wheee, user has trashed his/her sta 199 /* Wheee, user has trashed his/her stack. We have to decide
200 * how to proceed based upon whether w 200 * how to proceed based upon whether we came from kernel mode
201 * or not. If we came from kernel mod 201 * or not. If we came from kernel mode, toss the window into
202 * a special buffer and proceed, the k 202 * a special buffer and proceed, the kernel _needs_ a window
203 * and we could be in an interrupt han 203 * and we could be in an interrupt handler so timing is crucial.
204 * If we came from user land we build 204 * If we came from user land we build a full stack frame and call
205 * c-code to gun down the process. 205 * c-code to gun down the process.
206 */ 206 */
207 rd %psr, %glob_tmp 207 rd %psr, %glob_tmp
208 andcc %glob_tmp, PSR_PS, %g0 208 andcc %glob_tmp, PSR_PS, %g0
209 bne spwin_bad_ustack_from_kernel 209 bne spwin_bad_ustack_from_kernel
210 nop 210 nop
211 211
212 /* Oh well, throw this one window into 212 /* Oh well, throw this one window into the per-task window
213 * buffer, the first one. 213 * buffer, the first one.
214 */ 214 */
215 st %sp, [%curptr + TI_RWIN_SPTRS] 215 st %sp, [%curptr + TI_RWIN_SPTRS]
216 STORE_WINDOW(curptr + TI_REG_WINDOW) 216 STORE_WINDOW(curptr + TI_REG_WINDOW)
217 restore %g0, %g0, %g0 217 restore %g0, %g0, %g0
218 218
219 /* LOCATION: Trap Window */ 219 /* LOCATION: Trap Window */
220 220
221 /* Back in the trap window, update win 221 /* Back in the trap window, update winbuffer save count. */
222 mov 1, %twin_tmp 222 mov 1, %twin_tmp
223 st %twin_tmp, [%curptr + TI_W_SAV 223 st %twin_tmp, [%curptr + TI_W_SAVED]
224 224
225 /* Compute new user window mas 225 /* Compute new user window mask. What we are basically
226 * doing is taking two windows 226 * doing is taking two windows, the invalid one at trap
227 * time and the one we attempt 227 * time and the one we attempted to throw onto the users
228 * stack, and saying that ever 228 * stack, and saying that everything else is an ok user
229 * window. umask = ((~(%t_wim 229 * window. umask = ((~(%t_wim | %wim)) & valid_wim_bits)
230 */ 230 */
231 rd %wim, %twin_tmp 231 rd %wim, %twin_tmp
232 or %twin_tmp, %t_wim, %tw 232 or %twin_tmp, %t_wim, %twin_tmp
233 not %twin_tmp 233 not %twin_tmp
234 spnwin_patch3: and %twin_tmp, 0xff, %twin 234 spnwin_patch3: and %twin_tmp, 0xff, %twin_tmp ! patched on 7win Sparcs
235 st %twin_tmp, [%curptr + 235 st %twin_tmp, [%curptr + TI_UWINMASK]
236 236
237 #define STACK_OFFSET (THREAD_SIZE - TRACEREG_S 237 #define STACK_OFFSET (THREAD_SIZE - TRACEREG_SZ - STACKFRAME_SZ)
238 238
239 sethi %hi(STACK_OFFSET), %sp 239 sethi %hi(STACK_OFFSET), %sp
240 or %sp, %lo(STACK_OFFSET), %sp 240 or %sp, %lo(STACK_OFFSET), %sp
241 add %curptr, %sp, %sp 241 add %curptr, %sp, %sp
242 242
243 /* Restore the saved globals and build 243 /* Restore the saved globals and build a pt_regs frame. */
244 mov %saved_g5, %g5 244 mov %saved_g5, %g5
245 mov %saved_g6, %g6 245 mov %saved_g6, %g6
246 STORE_PT_ALL(sp, t_psr, t_pc, t_npc, g 246 STORE_PT_ALL(sp, t_psr, t_pc, t_npc, g1)
247 247
248 sethi %hi(STACK_OFFSET), %g6 248 sethi %hi(STACK_OFFSET), %g6
249 or %g6, %lo(STACK_OFFSET), %g6 249 or %g6, %lo(STACK_OFFSET), %g6
250 sub %sp, %g6, %g6 ! curp 250 sub %sp, %g6, %g6 ! curptr
251 251
252 /* Turn on traps and call c-code to de 252 /* Turn on traps and call c-code to deal with it. */
253 wr %t_psr, PSR_ET, %psr 253 wr %t_psr, PSR_ET, %psr
254 nop 254 nop
255 call window_overflow_fault 255 call window_overflow_fault
256 nop 256 nop
257 257
258 /* Return from trap if C-code actually 258 /* Return from trap if C-code actually fixes things, if it
259 * doesn't then we never get this far 259 * doesn't then we never get this far as the process will
260 * be given the look of death from Com 260 * be given the look of death from Commander Peanut.
261 */ 261 */
262 b ret_trap_entry 262 b ret_trap_entry
263 clr %l6 263 clr %l6
264 264
265 spwin_bad_ustack_from_kernel: 265 spwin_bad_ustack_from_kernel:
266 /* LOCATION: Window to be saved */ 266 /* LOCATION: Window to be saved */
267 267
268 /* The kernel provoked a spill window 268 /* The kernel provoked a spill window trap, but the window we
269 * need to save is a user one and the 269 * need to save is a user one and the process has trashed its
270 * stack pointer. We need to be quick 270 * stack pointer. We need to be quick, so we throw it into
271 * a per-process window buffer until w 271 * a per-process window buffer until we can properly handle
272 * this later on. 272 * this later on.
273 */ 273 */
274 SAVE_BOLIXED_USER_STACK(curptr, glob_t 274 SAVE_BOLIXED_USER_STACK(curptr, glob_tmp)
275 restore %g0, %g0, %g0 275 restore %g0, %g0, %g0
276 276
277 /* LOCATION: Trap window */ 277 /* LOCATION: Trap window */
278 278
279 /* Restore globals, condition codes in 279 /* Restore globals, condition codes in the %psr and
280 * return from trap. Note, restoring 280 * return from trap. Note, restoring %g6 when returning
281 * to kernel mode is not necessarily t 281 * to kernel mode is not necessarily these days. ;-)
282 */ 282 */
283 mov %saved_g5, %g5 283 mov %saved_g5, %g5
284 mov %saved_g6, %g6 284 mov %saved_g6, %g6
285 285
286 wr %t_psr, 0x0, %psr 286 wr %t_psr, 0x0, %psr
287 WRITE_PAUSE 287 WRITE_PAUSE
288 288
289 jmp %t_pc 289 jmp %t_pc
290 rett %t_npc 290 rett %t_npc
291 291
292 /* Undefine the register macros which would on 292 /* Undefine the register macros which would only cause trouble
293 * if used below. This helps find 'stupid' co 293 * if used below. This helps find 'stupid' coding errors that
294 * produce 'odd' behavior. The routines below 294 * produce 'odd' behavior. The routines below are allowed to
295 * make usage of glob_tmp and t_psr so we leav 295 * make usage of glob_tmp and t_psr so we leave them defined.
296 */ 296 */
297 #undef twin_tmp 297 #undef twin_tmp
298 #undef curptr 298 #undef curptr
299 #undef t_pc 299 #undef t_pc
300 #undef t_npc 300 #undef t_npc
301 #undef t_wim 301 #undef t_wim
302 #undef saved_g5 302 #undef saved_g5
303 #undef saved_g6 303 #undef saved_g6
304 304
305 /* Now come the per-architecture window overfl 305 /* Now come the per-architecture window overflow stack checking routines.
306 * As noted above %curptr cannot be touched by 306 * As noted above %curptr cannot be touched by this routine at all.
307 */ 307 */
308 308
309 /* This is a generic SRMMU routine. A 309 /* This is a generic SRMMU routine. As far as I know this
310 * works for all current v8/srmmu impl 310 * works for all current v8/srmmu implementations, we'll
311 * see... 311 * see...
312 */ 312 */
313 .globl spwin_srmmu_stackchk 313 .globl spwin_srmmu_stackchk
314 spwin_srmmu_stackchk: 314 spwin_srmmu_stackchk:
315 /* LOCATION: Window to be saved on the 315 /* LOCATION: Window to be saved on the stack */
316 316
317 /* Because of SMP concerns and speed w 317 /* Because of SMP concerns and speed we play a trick.
318 * We disable fault traps in the MMU c 318 * We disable fault traps in the MMU control register,
319 * Execute the stores, then check the 319 * Execute the stores, then check the fault registers
320 * to see what happens. I can hear Li 320 * to see what happens. I can hear Linus now
321 * "disgusting... broken hardware...". 321 * "disgusting... broken hardware...".
322 * 322 *
323 * But first, check to see if the user 323 * But first, check to see if the users stack has ended
324 * up in kernel vma, then we would suc 324 * up in kernel vma, then we would succeed for the 'wrong'
325 * reason... ;( Note that the 'sethi' 325 * reason... ;( Note that the 'sethi' below assumes the
326 * kernel is page aligned, which shoul 326 * kernel is page aligned, which should always be the case.
327 */ 327 */
328 /* Check results of callers andcc %sp, 328 /* Check results of callers andcc %sp, 0x7, %g0 */
329 bne spwin_user_stack_is_bolixed 329 bne spwin_user_stack_is_bolixed
330 sethi %hi(PAGE_OFFSET), %glob_tmp 330 sethi %hi(PAGE_OFFSET), %glob_tmp
331 cmp %glob_tmp, %sp 331 cmp %glob_tmp, %sp
332 bleu spwin_user_stack_is_bolixed 332 bleu spwin_user_stack_is_bolixed
333 mov AC_M_SFSR, %glob_tmp 333 mov AC_M_SFSR, %glob_tmp
334 334
335 /* Clear the fault status and turn on 335 /* Clear the fault status and turn on the no_fault bit. */
336 LEON_PI(lda [%glob_tmp] ASI_LEON_MMUREGS, 336 LEON_PI(lda [%glob_tmp] ASI_LEON_MMUREGS, %g0) ! eat SFSR
337 SUN_PI_(lda [%glob_tmp] ASI_M_MMUREGS, %g0 337 SUN_PI_(lda [%glob_tmp] ASI_M_MMUREGS, %g0) ! eat SFSR
338 338
339 LEON_PI(lda [%g0] ASI_LEON_MMUREGS, %glob_ 339 LEON_PI(lda [%g0] ASI_LEON_MMUREGS, %glob_tmp) ! read MMU control
340 SUN_PI_(lda [%g0] ASI_M_MMUREGS, %glob_tmp 340 SUN_PI_(lda [%g0] ASI_M_MMUREGS, %glob_tmp) ! read MMU control
341 or %glob_tmp, 0x2, %glob_tmp 341 or %glob_tmp, 0x2, %glob_tmp ! or in no_fault bit
342 LEON_PI(sta %glob_tmp, [%g0] ASI_LEON_MMUR 342 LEON_PI(sta %glob_tmp, [%g0] ASI_LEON_MMUREGS) ! set it
343 SUN_PI_(sta %glob_tmp, [%g0] ASI_M_MMUREGS 343 SUN_PI_(sta %glob_tmp, [%g0] ASI_M_MMUREGS) ! set it
344 344
345 /* Dump the registers and cross finger 345 /* Dump the registers and cross fingers. */
346 STORE_WINDOW(sp) 346 STORE_WINDOW(sp)
347 347
348 /* Clear the no_fault bit and check th 348 /* Clear the no_fault bit and check the status. */
349 andn %glob_tmp, 0x2, %glob_tmp 349 andn %glob_tmp, 0x2, %glob_tmp
350 LEON_PI(sta %glob_tmp, [%g0] ASI_LEON_MMUR 350 LEON_PI(sta %glob_tmp, [%g0] ASI_LEON_MMUREGS)
351 SUN_PI_(sta %glob_tmp, [%g0] ASI_M_MMUREGS 351 SUN_PI_(sta %glob_tmp, [%g0] ASI_M_MMUREGS)
352 352
353 mov AC_M_SFAR, %glob_tmp 353 mov AC_M_SFAR, %glob_tmp
354 LEON_PI(lda [%glob_tmp] ASI_LEON_MMUREGS, 354 LEON_PI(lda [%glob_tmp] ASI_LEON_MMUREGS, %g0)
355 SUN_PI_(lda [%glob_tmp] ASI_M_MMUREGS, %g0 355 SUN_PI_(lda [%glob_tmp] ASI_M_MMUREGS, %g0)
356 356
357 mov AC_M_SFSR, %glob_tmp 357 mov AC_M_SFSR, %glob_tmp
358 LEON_PI(lda [%glob_tmp] ASI_LEON_MMUREGS, 358 LEON_PI(lda [%glob_tmp] ASI_LEON_MMUREGS, %glob_tmp)
359 SUN_PI_(lda [%glob_tmp] ASI_M_MMUREGS, %gl 359 SUN_PI_(lda [%glob_tmp] ASI_M_MMUREGS, %glob_tmp)
360 andcc %glob_tmp, 0x2, %g0 360 andcc %glob_tmp, 0x2, %g0 ! did we fault?
361 be,a spwin_finish_up + 0x4 361 be,a spwin_finish_up + 0x4 ! cool beans, success
362 restore %g0, %g0, %g0 362 restore %g0, %g0, %g0
363 363
364 rd %psr, %glob_tmp 364 rd %psr, %glob_tmp
365 b spwin_user_stack_is_bolixed + 365 b spwin_user_stack_is_bolixed + 0x4 ! we faulted, ugh
366 nop 366 nop
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