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ca54502b MS |
1 | /* |
2 | * Low-level system-call handling, trap handlers and context-switching | |
3 | * | |
4 | * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> | |
5 | * Copyright (C) 2008-2009 PetaLogix | |
6 | * Copyright (C) 2003 John Williams <jwilliams@itee.uq.edu.au> | |
7 | * Copyright (C) 2001,2002 NEC Corporation | |
8 | * Copyright (C) 2001,2002 Miles Bader <miles@gnu.org> | |
9 | * | |
10 | * This file is subject to the terms and conditions of the GNU General | |
11 | * Public License. See the file COPYING in the main directory of this | |
12 | * archive for more details. | |
13 | * | |
14 | * Written by Miles Bader <miles@gnu.org> | |
15 | * Heavily modified by John Williams for Microblaze | |
16 | */ | |
17 | ||
18 | #include <linux/sys.h> | |
19 | #include <linux/linkage.h> | |
20 | ||
21 | #include <asm/entry.h> | |
22 | #include <asm/current.h> | |
23 | #include <asm/processor.h> | |
24 | #include <asm/exceptions.h> | |
25 | #include <asm/asm-offsets.h> | |
26 | #include <asm/thread_info.h> | |
27 | ||
28 | #include <asm/page.h> | |
29 | #include <asm/unistd.h> | |
30 | ||
31 | #include <linux/errno.h> | |
32 | #include <asm/signal.h> | |
33 | ||
11d51360 MS |
34 | #undef DEBUG |
35 | ||
ca54502b MS |
36 | /* The size of a state save frame. */ |
37 | #define STATE_SAVE_SIZE (PT_SIZE + STATE_SAVE_ARG_SPACE) | |
38 | ||
39 | /* The offset of the struct pt_regs in a `state save frame' on the stack. */ | |
40 | #define PTO STATE_SAVE_ARG_SPACE /* 24 the space for args */ | |
41 | ||
42 | #define C_ENTRY(name) .globl name; .align 4; name | |
43 | ||
44 | /* | |
45 | * Various ways of setting and clearing BIP in flags reg. | |
46 | * This is mucky, but necessary using microblaze version that | |
47 | * allows msr ops to write to BIP | |
48 | */ | |
49 | #if CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR | |
50 | .macro clear_bip | |
66f7de86 | 51 | msrclr r0, MSR_BIP |
ca54502b MS |
52 | nop |
53 | .endm | |
54 | ||
55 | .macro set_bip | |
66f7de86 | 56 | msrset r0, MSR_BIP |
ca54502b MS |
57 | nop |
58 | .endm | |
59 | ||
60 | .macro clear_eip | |
66f7de86 | 61 | msrclr r0, MSR_EIP |
ca54502b MS |
62 | nop |
63 | .endm | |
64 | ||
65 | .macro set_ee | |
66f7de86 | 66 | msrset r0, MSR_EE |
ca54502b MS |
67 | nop |
68 | .endm | |
69 | ||
70 | .macro disable_irq | |
66f7de86 | 71 | msrclr r0, MSR_IE |
ca54502b MS |
72 | nop |
73 | .endm | |
74 | ||
75 | .macro enable_irq | |
66f7de86 | 76 | msrset r0, MSR_IE |
ca54502b MS |
77 | nop |
78 | .endm | |
79 | ||
80 | .macro set_ums | |
66f7de86 | 81 | msrset r0, MSR_UMS |
ca54502b | 82 | nop |
66f7de86 | 83 | msrclr r0, MSR_VMS |
ca54502b MS |
84 | nop |
85 | .endm | |
86 | ||
87 | .macro set_vms | |
66f7de86 | 88 | msrclr r0, MSR_UMS |
ca54502b | 89 | nop |
66f7de86 | 90 | msrset r0, MSR_VMS |
ca54502b MS |
91 | nop |
92 | .endm | |
93 | ||
b318067e | 94 | .macro clear_ums |
66f7de86 | 95 | msrclr r0, MSR_UMS |
b318067e MS |
96 | nop |
97 | .endm | |
98 | ||
ca54502b | 99 | .macro clear_vms_ums |
66f7de86 | 100 | msrclr r0, MSR_VMS | MSR_UMS |
ca54502b MS |
101 | nop |
102 | .endm | |
103 | #else | |
104 | .macro clear_bip | |
105 | mfs r11, rmsr | |
106 | nop | |
107 | andi r11, r11, ~MSR_BIP | |
108 | mts rmsr, r11 | |
109 | nop | |
110 | .endm | |
111 | ||
112 | .macro set_bip | |
113 | mfs r11, rmsr | |
114 | nop | |
115 | ori r11, r11, MSR_BIP | |
116 | mts rmsr, r11 | |
117 | nop | |
118 | .endm | |
119 | ||
120 | .macro clear_eip | |
121 | mfs r11, rmsr | |
122 | nop | |
123 | andi r11, r11, ~MSR_EIP | |
124 | mts rmsr, r11 | |
125 | nop | |
126 | .endm | |
127 | ||
128 | .macro set_ee | |
129 | mfs r11, rmsr | |
130 | nop | |
131 | ori r11, r11, MSR_EE | |
132 | mts rmsr, r11 | |
133 | nop | |
134 | .endm | |
135 | ||
136 | .macro disable_irq | |
137 | mfs r11, rmsr | |
138 | nop | |
139 | andi r11, r11, ~MSR_IE | |
140 | mts rmsr, r11 | |
141 | nop | |
142 | .endm | |
143 | ||
144 | .macro enable_irq | |
145 | mfs r11, rmsr | |
146 | nop | |
147 | ori r11, r11, MSR_IE | |
148 | mts rmsr, r11 | |
149 | nop | |
150 | .endm | |
151 | ||
152 | .macro set_ums | |
153 | mfs r11, rmsr | |
154 | nop | |
155 | ori r11, r11, MSR_VMS | |
156 | andni r11, r11, MSR_UMS | |
157 | mts rmsr, r11 | |
158 | nop | |
159 | .endm | |
160 | ||
161 | .macro set_vms | |
162 | mfs r11, rmsr | |
163 | nop | |
164 | ori r11, r11, MSR_VMS | |
165 | andni r11, r11, MSR_UMS | |
166 | mts rmsr, r11 | |
167 | nop | |
168 | .endm | |
169 | ||
b318067e MS |
170 | .macro clear_ums |
171 | mfs r11, rmsr | |
172 | nop | |
173 | andni r11, r11, MSR_UMS | |
174 | mts rmsr,r11 | |
175 | nop | |
176 | .endm | |
177 | ||
ca54502b MS |
178 | .macro clear_vms_ums |
179 | mfs r11, rmsr | |
180 | nop | |
181 | andni r11, r11, (MSR_VMS|MSR_UMS) | |
182 | mts rmsr,r11 | |
183 | nop | |
184 | .endm | |
185 | #endif | |
186 | ||
187 | /* Define how to call high-level functions. With MMU, virtual mode must be | |
188 | * enabled when calling the high-level function. Clobbers R11. | |
189 | * VM_ON, VM_OFF, DO_JUMP_BIPCLR, DO_CALL | |
190 | */ | |
191 | ||
192 | /* turn on virtual protected mode save */ | |
193 | #define VM_ON \ | |
a4a94dbf | 194 | set_ums; \ |
ca54502b | 195 | rted r0, 2f; \ |
a4a94dbf MS |
196 | nop; \ |
197 | 2: | |
ca54502b MS |
198 | |
199 | /* turn off virtual protected mode save and user mode save*/ | |
200 | #define VM_OFF \ | |
a4a94dbf | 201 | clear_vms_ums; \ |
ca54502b | 202 | rted r0, TOPHYS(1f); \ |
a4a94dbf MS |
203 | nop; \ |
204 | 1: | |
ca54502b MS |
205 | |
206 | #define SAVE_REGS \ | |
207 | swi r2, r1, PTO+PT_R2; /* Save SDA */ \ | |
36f60954 MS |
208 | swi r3, r1, PTO+PT_R3; \ |
209 | swi r4, r1, PTO+PT_R4; \ | |
ca54502b MS |
210 | swi r5, r1, PTO+PT_R5; \ |
211 | swi r6, r1, PTO+PT_R6; \ | |
212 | swi r7, r1, PTO+PT_R7; \ | |
213 | swi r8, r1, PTO+PT_R8; \ | |
214 | swi r9, r1, PTO+PT_R9; \ | |
215 | swi r10, r1, PTO+PT_R10; \ | |
216 | swi r11, r1, PTO+PT_R11; /* save clobbered regs after rval */\ | |
217 | swi r12, r1, PTO+PT_R12; \ | |
218 | swi r13, r1, PTO+PT_R13; /* Save SDA2 */ \ | |
219 | swi r14, r1, PTO+PT_PC; /* PC, before IRQ/trap */ \ | |
220 | swi r15, r1, PTO+PT_R15; /* Save LP */ \ | |
221 | swi r18, r1, PTO+PT_R18; /* Save asm scratch reg */ \ | |
222 | swi r19, r1, PTO+PT_R19; \ | |
223 | swi r20, r1, PTO+PT_R20; \ | |
224 | swi r21, r1, PTO+PT_R21; \ | |
225 | swi r22, r1, PTO+PT_R22; \ | |
226 | swi r23, r1, PTO+PT_R23; \ | |
227 | swi r24, r1, PTO+PT_R24; \ | |
228 | swi r25, r1, PTO+PT_R25; \ | |
229 | swi r26, r1, PTO+PT_R26; \ | |
230 | swi r27, r1, PTO+PT_R27; \ | |
231 | swi r28, r1, PTO+PT_R28; \ | |
232 | swi r29, r1, PTO+PT_R29; \ | |
233 | swi r30, r1, PTO+PT_R30; \ | |
234 | swi r31, r1, PTO+PT_R31; /* Save current task reg */ \ | |
235 | mfs r11, rmsr; /* save MSR */ \ | |
236 | nop; \ | |
237 | swi r11, r1, PTO+PT_MSR; | |
238 | ||
239 | #define RESTORE_REGS \ | |
240 | lwi r11, r1, PTO+PT_MSR; \ | |
241 | mts rmsr , r11; \ | |
242 | nop; \ | |
243 | lwi r2, r1, PTO+PT_R2; /* restore SDA */ \ | |
36f60954 MS |
244 | lwi r3, r1, PTO+PT_R3; \ |
245 | lwi r4, r1, PTO+PT_R4; \ | |
ca54502b MS |
246 | lwi r5, r1, PTO+PT_R5; \ |
247 | lwi r6, r1, PTO+PT_R6; \ | |
248 | lwi r7, r1, PTO+PT_R7; \ | |
249 | lwi r8, r1, PTO+PT_R8; \ | |
250 | lwi r9, r1, PTO+PT_R9; \ | |
251 | lwi r10, r1, PTO+PT_R10; \ | |
252 | lwi r11, r1, PTO+PT_R11; /* restore clobbered regs after rval */\ | |
253 | lwi r12, r1, PTO+PT_R12; \ | |
254 | lwi r13, r1, PTO+PT_R13; /* restore SDA2 */ \ | |
255 | lwi r14, r1, PTO+PT_PC; /* RESTORE_LINK PC, before IRQ/trap */\ | |
256 | lwi r15, r1, PTO+PT_R15; /* restore LP */ \ | |
257 | lwi r18, r1, PTO+PT_R18; /* restore asm scratch reg */ \ | |
258 | lwi r19, r1, PTO+PT_R19; \ | |
259 | lwi r20, r1, PTO+PT_R20; \ | |
260 | lwi r21, r1, PTO+PT_R21; \ | |
261 | lwi r22, r1, PTO+PT_R22; \ | |
262 | lwi r23, r1, PTO+PT_R23; \ | |
263 | lwi r24, r1, PTO+PT_R24; \ | |
264 | lwi r25, r1, PTO+PT_R25; \ | |
265 | lwi r26, r1, PTO+PT_R26; \ | |
266 | lwi r27, r1, PTO+PT_R27; \ | |
267 | lwi r28, r1, PTO+PT_R28; \ | |
268 | lwi r29, r1, PTO+PT_R29; \ | |
269 | lwi r30, r1, PTO+PT_R30; \ | |
270 | lwi r31, r1, PTO+PT_R31; /* Restore cur task reg */ | |
271 | ||
e5d2af2b MS |
272 | #define SAVE_STATE \ |
273 | swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* save stack */ \ | |
274 | /* See if already in kernel mode.*/ \ | |
275 | mfs r1, rmsr; \ | |
276 | nop; \ | |
277 | andi r1, r1, MSR_UMS; \ | |
278 | bnei r1, 1f; \ | |
279 | /* Kernel-mode state save. */ \ | |
280 | /* Reload kernel stack-ptr. */ \ | |
281 | lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); \ | |
287503fa MS |
282 | /* FIXME: I can add these two lines to one */ \ |
283 | /* tophys(r1,r1); */ \ | |
284 | /* addik r1, r1, -STATE_SAVE_SIZE; */ \ | |
285 | addik r1, r1, CONFIG_KERNEL_BASE_ADDR - CONFIG_KERNEL_START - STATE_SAVE_SIZE; \ | |
e5d2af2b | 286 | SAVE_REGS \ |
e5d2af2b | 287 | brid 2f; \ |
da233552 | 288 | swi r1, r1, PTO+PT_MODE; \ |
e5d2af2b MS |
289 | 1: /* User-mode state save. */ \ |
290 | lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */\ | |
291 | tophys(r1,r1); \ | |
292 | lwi r1, r1, TS_THREAD_INFO; /* get the thread info */ \ | |
287503fa MS |
293 | /* MS these three instructions can be added to one */ \ |
294 | /* addik r1, r1, THREAD_SIZE; */ \ | |
295 | /* tophys(r1,r1); */ \ | |
296 | /* addik r1, r1, -STATE_SAVE_SIZE; */ \ | |
297 | addik r1, r1, THREAD_SIZE + CONFIG_KERNEL_BASE_ADDR - CONFIG_KERNEL_START - STATE_SAVE_SIZE; \ | |
e5d2af2b | 298 | SAVE_REGS \ |
e5d2af2b MS |
299 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \ |
300 | swi r11, r1, PTO+PT_R1; /* Store user SP. */ \ | |
e7741075 | 301 | swi r0, r1, PTO + PT_MODE; /* Was in user-mode. */ \ |
e5d2af2b MS |
302 | /* MS: I am clearing UMS even in case when I come from kernel space */ \ |
303 | clear_ums; \ | |
304 | 2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); | |
305 | ||
ca54502b MS |
306 | .text |
307 | ||
308 | /* | |
309 | * User trap. | |
310 | * | |
311 | * System calls are handled here. | |
312 | * | |
313 | * Syscall protocol: | |
314 | * Syscall number in r12, args in r5-r10 | |
315 | * Return value in r3 | |
316 | * | |
317 | * Trap entered via brki instruction, so BIP bit is set, and interrupts | |
318 | * are masked. This is nice, means we don't have to CLI before state save | |
319 | */ | |
320 | C_ENTRY(_user_exception): | |
321 | swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ | |
322 | addi r14, r14, 4 /* return address is 4 byte after call */ | |
ca54502b | 323 | |
653e447e | 324 | mfs r1, rmsr |
5c0d72b1 | 325 | nop |
653e447e MS |
326 | andi r1, r1, MSR_UMS |
327 | bnei r1, 1f | |
5c0d72b1 MS |
328 | |
329 | /* Kernel-mode state save - kernel execve */ | |
653e447e MS |
330 | lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/ |
331 | tophys(r1,r1); | |
ca54502b MS |
332 | |
333 | addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ | |
334 | SAVE_REGS | |
335 | ||
77f6d226 | 336 | swi r1, r1, PTO + PT_MODE; /* pt_regs -> kernel mode */ |
ca54502b MS |
337 | brid 2f; |
338 | nop; /* Fill delay slot */ | |
339 | ||
340 | /* User-mode state save. */ | |
341 | 1: | |
ca54502b MS |
342 | lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */ |
343 | tophys(r1,r1); | |
344 | lwi r1, r1, TS_THREAD_INFO; /* get stack from task_struct */ | |
345 | /* calculate kernel stack pointer from task struct 8k */ | |
346 | addik r1, r1, THREAD_SIZE; | |
347 | tophys(r1,r1); | |
348 | ||
349 | addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ | |
350 | SAVE_REGS | |
351 | ||
77f6d226 | 352 | swi r0, r1, PTO + PT_MODE; /* Was in user-mode. */ |
ca54502b MS |
353 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); |
354 | swi r11, r1, PTO+PT_R1; /* Store user SP. */ | |
b1d70c62 | 355 | 2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); |
ca54502b MS |
356 | /* Save away the syscall number. */ |
357 | swi r12, r1, PTO+PT_R0; | |
358 | tovirt(r1,r1) | |
359 | ||
ca54502b MS |
360 | /* where the trap should return need -8 to adjust for rtsd r15, 8*/ |
361 | /* Jump to the appropriate function for the system call number in r12 | |
362 | * (r12 is not preserved), or return an error if r12 is not valid. The LP | |
363 | * register should point to the location where | |
364 | * the called function should return. [note that MAKE_SYS_CALL uses label 1] */ | |
23575483 MS |
365 | |
366 | # Step into virtual mode. | |
367 | set_vms; | |
368 | addik r11, r0, 3f | |
369 | rtid r11, 0 | |
370 | nop | |
371 | 3: | |
b1d70c62 | 372 | lwi r11, CURRENT_TASK, TS_THREAD_INFO /* get thread info */ |
23575483 MS |
373 | lwi r11, r11, TI_FLAGS /* get flags in thread info */ |
374 | andi r11, r11, _TIF_WORK_SYSCALL_MASK | |
375 | beqi r11, 4f | |
376 | ||
377 | addik r3, r0, -ENOSYS | |
378 | swi r3, r1, PTO + PT_R3 | |
379 | brlid r15, do_syscall_trace_enter | |
380 | addik r5, r1, PTO + PT_R0 | |
381 | ||
382 | # do_syscall_trace_enter returns the new syscall nr. | |
383 | addk r12, r0, r3 | |
384 | lwi r5, r1, PTO+PT_R5; | |
385 | lwi r6, r1, PTO+PT_R6; | |
386 | lwi r7, r1, PTO+PT_R7; | |
387 | lwi r8, r1, PTO+PT_R8; | |
388 | lwi r9, r1, PTO+PT_R9; | |
389 | lwi r10, r1, PTO+PT_R10; | |
390 | 4: | |
391 | /* Jump to the appropriate function for the system call number in r12 | |
392 | * (r12 is not preserved), or return an error if r12 is not valid. | |
393 | * The LP register should point to the location where the called function | |
394 | * should return. [note that MAKE_SYS_CALL uses label 1] */ | |
395 | /* See if the system call number is valid */ | |
ca54502b | 396 | addi r11, r12, -__NR_syscalls; |
23575483 | 397 | bgei r11,5f; |
ca54502b MS |
398 | /* Figure out which function to use for this system call. */ |
399 | /* Note Microblaze barrel shift is optional, so don't rely on it */ | |
400 | add r12, r12, r12; /* convert num -> ptr */ | |
401 | add r12, r12, r12; | |
402 | ||
11d51360 | 403 | #ifdef DEBUG |
ca54502b | 404 | /* Trac syscalls and stored them to r0_ram */ |
23575483 | 405 | lwi r3, r12, 0x400 + r0_ram |
ca54502b | 406 | addi r3, r3, 1 |
23575483 | 407 | swi r3, r12, 0x400 + r0_ram |
11d51360 | 408 | #endif |
23575483 MS |
409 | |
410 | # Find and jump into the syscall handler. | |
411 | lwi r12, r12, sys_call_table | |
412 | /* where the trap should return need -8 to adjust for rtsd r15, 8 */ | |
b9ea77e2 | 413 | addi r15, r0, ret_from_trap-8 |
23575483 | 414 | bra r12 |
ca54502b | 415 | |
ca54502b | 416 | /* The syscall number is invalid, return an error. */ |
23575483 | 417 | 5: |
9814cc11 | 418 | rtsd r15, 8; /* looks like a normal subroutine return */ |
ca54502b | 419 | addi r3, r0, -ENOSYS; |
ca54502b | 420 | |
23575483 | 421 | /* Entry point used to return from a syscall/trap */ |
ca54502b MS |
422 | /* We re-enable BIP bit before state restore */ |
423 | C_ENTRY(ret_from_trap): | |
b1d70c62 MS |
424 | swi r3, r1, PTO + PT_R3 |
425 | swi r4, r1, PTO + PT_R4 | |
426 | ||
77f6d226 | 427 | lwi r11, r1, PTO + PT_MODE; |
36f60954 MS |
428 | /* See if returning to kernel mode, if so, skip resched &c. */ |
429 | bnei r11, 2f; | |
23575483 MS |
430 | /* We're returning to user mode, so check for various conditions that |
431 | * trigger rescheduling. */ | |
b1d70c62 MS |
432 | /* FIXME: Restructure all these flag checks. */ |
433 | lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */ | |
23575483 MS |
434 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
435 | andi r11, r11, _TIF_WORK_SYSCALL_MASK | |
436 | beqi r11, 1f | |
437 | ||
23575483 MS |
438 | brlid r15, do_syscall_trace_leave |
439 | addik r5, r1, PTO + PT_R0 | |
23575483 | 440 | 1: |
ca54502b MS |
441 | /* We're returning to user mode, so check for various conditions that |
442 | * trigger rescheduling. */ | |
b1d70c62 MS |
443 | /* get thread info from current task */ |
444 | lwi r11, CURRENT_TASK, TS_THREAD_INFO; | |
ca54502b MS |
445 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
446 | andi r11, r11, _TIF_NEED_RESCHED; | |
447 | beqi r11, 5f; | |
448 | ||
ca54502b MS |
449 | bralid r15, schedule; /* Call scheduler */ |
450 | nop; /* delay slot */ | |
ca54502b MS |
451 | |
452 | /* Maybe handle a signal */ | |
b1d70c62 MS |
453 | 5: /* get thread info from current task*/ |
454 | lwi r11, CURRENT_TASK, TS_THREAD_INFO; | |
ca54502b MS |
455 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
456 | andi r11, r11, _TIF_SIGPENDING; | |
457 | beqi r11, 1f; /* Signals to handle, handle them */ | |
458 | ||
b9ea77e2 | 459 | addik r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ |
ca54502b MS |
460 | addi r7, r0, 1; /* Arg 3: int in_syscall */ |
461 | bralid r15, do_signal; /* Handle any signals */ | |
841d6e8c | 462 | add r6, r0, r0; /* Arg 2: sigset_t *oldset */ |
b1d70c62 MS |
463 | |
464 | /* Finally, return to user state. */ | |
96014cc3 | 465 | 1: set_bip; /* Ints masked for state restore */ |
8633bebc | 466 | swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */ |
ca54502b MS |
467 | VM_OFF; |
468 | tophys(r1,r1); | |
469 | RESTORE_REGS; | |
470 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ | |
471 | lwi r1, r1, PT_R1 - PT_SIZE;/* Restore user stack pointer. */ | |
472 | bri 6f; | |
473 | ||
474 | /* Return to kernel state. */ | |
96014cc3 MS |
475 | 2: set_bip; /* Ints masked for state restore */ |
476 | VM_OFF; | |
ca54502b MS |
477 | tophys(r1,r1); |
478 | RESTORE_REGS; | |
479 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ | |
480 | tovirt(r1,r1); | |
481 | 6: | |
482 | TRAP_return: /* Make global symbol for debugging */ | |
483 | rtbd r14, 0; /* Instructions to return from an IRQ */ | |
484 | nop; | |
485 | ||
486 | ||
487 | /* These syscalls need access to the struct pt_regs on the stack, so we | |
488 | implement them in assembly (they're basically all wrappers anyway). */ | |
489 | ||
490 | C_ENTRY(sys_fork_wrapper): | |
491 | addi r5, r0, SIGCHLD /* Arg 0: flags */ | |
492 | lwi r6, r1, PTO+PT_R1 /* Arg 1: child SP (use parent's) */ | |
b9ea77e2 | 493 | addik r7, r1, PTO /* Arg 2: parent context */ |
ca54502b MS |
494 | add r8. r0, r0 /* Arg 3: (unused) */ |
495 | add r9, r0, r0; /* Arg 4: (unused) */ | |
ca54502b | 496 | brid do_fork /* Do real work (tail-call) */ |
9814cc11 | 497 | add r10, r0, r0; /* Arg 5: (unused) */ |
ca54502b MS |
498 | |
499 | /* This the initial entry point for a new child thread, with an appropriate | |
500 | stack in place that makes it look the the child is in the middle of an | |
501 | syscall. This function is actually `returned to' from switch_thread | |
502 | (copy_thread makes ret_from_fork the return address in each new thread's | |
503 | saved context). */ | |
504 | C_ENTRY(ret_from_fork): | |
505 | bralid r15, schedule_tail; /* ...which is schedule_tail's arg */ | |
506 | add r3, r5, r0; /* switch_thread returns the prev task */ | |
507 | /* ( in the delay slot ) */ | |
ca54502b | 508 | brid ret_from_trap; /* Do normal trap return */ |
9814cc11 | 509 | add r3, r0, r0; /* Child's fork call should return 0. */ |
ca54502b | 510 | |
e513588f AB |
511 | C_ENTRY(sys_vfork): |
512 | brid microblaze_vfork /* Do real work (tail-call) */ | |
b9ea77e2 | 513 | addik r5, r1, PTO |
ca54502b | 514 | |
e513588f | 515 | C_ENTRY(sys_clone): |
ca54502b | 516 | bnei r6, 1f; /* See if child SP arg (arg 1) is 0. */ |
570e3e23 | 517 | lwi r6, r1, PTO + PT_R1; /* If so, use paret's stack ptr */ |
b9ea77e2 MS |
518 | 1: addik r7, r1, PTO; /* Arg 2: parent context */ |
519 | add r8, r0, r0; /* Arg 3: (unused) */ | |
520 | add r9, r0, r0; /* Arg 4: (unused) */ | |
b9ea77e2 | 521 | brid do_fork /* Do real work (tail-call) */ |
9814cc11 | 522 | add r10, r0, r0; /* Arg 5: (unused) */ |
ca54502b | 523 | |
e513588f | 524 | C_ENTRY(sys_execve): |
e513588f | 525 | brid microblaze_execve; /* Do real work (tail-call).*/ |
9814cc11 | 526 | addik r8, r1, PTO; /* add user context as 4th arg */ |
ca54502b | 527 | |
ca54502b MS |
528 | C_ENTRY(sys_rt_sigreturn_wrapper): |
529 | swi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ | |
530 | swi r4, r1, PTO+PT_R4; | |
ca54502b | 531 | brlid r15, sys_rt_sigreturn /* Do real work */ |
9814cc11 | 532 | addik r5, r1, PTO; /* add user context as 1st arg */ |
ca54502b MS |
533 | lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ |
534 | lwi r4, r1, PTO+PT_R4; | |
535 | bri ret_from_trap /* fall through will not work here due to align */ | |
536 | nop; | |
537 | ||
538 | /* | |
539 | * HW EXCEPTION rutine start | |
540 | */ | |
ca54502b | 541 | C_ENTRY(full_exception_trap): |
ca54502b MS |
542 | /* adjust exception address for privileged instruction |
543 | * for finding where is it */ | |
544 | addik r17, r17, -4 | |
545 | SAVE_STATE /* Save registers */ | |
06a54604 MS |
546 | /* PC, before IRQ/trap - this is one instruction above */ |
547 | swi r17, r1, PTO+PT_PC; | |
548 | tovirt(r1,r1) | |
ca54502b MS |
549 | /* FIXME this can be store directly in PT_ESR reg. |
550 | * I tested it but there is a fault */ | |
551 | /* where the trap should return need -8 to adjust for rtsd r15, 8 */ | |
b9ea77e2 | 552 | addik r15, r0, ret_from_exc - 8 |
ca54502b MS |
553 | mfs r6, resr |
554 | nop | |
555 | mfs r7, rfsr; /* save FSR */ | |
556 | nop | |
131e4e97 MS |
557 | mts rfsr, r0; /* Clear sticky fsr */ |
558 | nop | |
c318d483 | 559 | rted r0, full_exception |
9814cc11 | 560 | addik r5, r1, PTO /* parameter struct pt_regs * regs */ |
ca54502b MS |
561 | |
562 | /* | |
563 | * Unaligned data trap. | |
564 | * | |
565 | * Unaligned data trap last on 4k page is handled here. | |
566 | * | |
567 | * Trap entered via exception, so EE bit is set, and interrupts | |
568 | * are masked. This is nice, means we don't have to CLI before state save | |
569 | * | |
570 | * The assembler routine is in "arch/microblaze/kernel/hw_exception_handler.S" | |
571 | */ | |
572 | C_ENTRY(unaligned_data_trap): | |
8b110d15 MS |
573 | /* MS: I have to save r11 value and then restore it because |
574 | * set_bit, clear_eip, set_ee use r11 as temp register if MSR | |
575 | * instructions are not used. We don't need to do if MSR instructions | |
576 | * are used and they use r0 instead of r11. | |
577 | * I am using ENTRY_SP which should be primary used only for stack | |
578 | * pointer saving. */ | |
579 | swi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); | |
580 | set_bip; /* equalize initial state for all possible entries */ | |
581 | clear_eip; | |
582 | set_ee; | |
583 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); | |
ca54502b | 584 | SAVE_STATE /* Save registers.*/ |
06a54604 MS |
585 | /* PC, before IRQ/trap - this is one instruction above */ |
586 | swi r17, r1, PTO+PT_PC; | |
587 | tovirt(r1,r1) | |
ca54502b | 588 | /* where the trap should return need -8 to adjust for rtsd r15, 8 */ |
b9ea77e2 | 589 | addik r15, r0, ret_from_exc-8 |
ca54502b MS |
590 | mfs r3, resr /* ESR */ |
591 | nop | |
592 | mfs r4, rear /* EAR */ | |
593 | nop | |
c318d483 | 594 | rtbd r0, _unaligned_data_exception |
b9ea77e2 | 595 | addik r7, r1, PTO /* parameter struct pt_regs * regs */ |
ca54502b MS |
596 | |
597 | /* | |
598 | * Page fault traps. | |
599 | * | |
600 | * If the real exception handler (from hw_exception_handler.S) didn't find | |
601 | * the mapping for the process, then we're thrown here to handle such situation. | |
602 | * | |
603 | * Trap entered via exceptions, so EE bit is set, and interrupts | |
604 | * are masked. This is nice, means we don't have to CLI before state save | |
605 | * | |
606 | * Build a standard exception frame for TLB Access errors. All TLB exceptions | |
607 | * will bail out to this point if they can't resolve the lightweight TLB fault. | |
608 | * | |
609 | * The C function called is in "arch/microblaze/mm/fault.c", declared as: | |
610 | * void do_page_fault(struct pt_regs *regs, | |
611 | * unsigned long address, | |
612 | * unsigned long error_code) | |
613 | */ | |
614 | /* data and intruction trap - which is choose is resolved int fault.c */ | |
615 | C_ENTRY(page_fault_data_trap): | |
ca54502b | 616 | SAVE_STATE /* Save registers.*/ |
06a54604 MS |
617 | /* PC, before IRQ/trap - this is one instruction above */ |
618 | swi r17, r1, PTO+PT_PC; | |
619 | tovirt(r1,r1) | |
ca54502b | 620 | /* where the trap should return need -8 to adjust for rtsd r15, 8 */ |
b9ea77e2 | 621 | addik r15, r0, ret_from_exc-8 |
ca54502b MS |
622 | mfs r6, rear /* parameter unsigned long address */ |
623 | nop | |
624 | mfs r7, resr /* parameter unsigned long error_code */ | |
625 | nop | |
c318d483 | 626 | rted r0, do_page_fault |
9814cc11 | 627 | addik r5, r1, PTO /* parameter struct pt_regs * regs */ |
ca54502b MS |
628 | |
629 | C_ENTRY(page_fault_instr_trap): | |
ca54502b | 630 | SAVE_STATE /* Save registers.*/ |
06a54604 MS |
631 | /* PC, before IRQ/trap - this is one instruction above */ |
632 | swi r17, r1, PTO+PT_PC; | |
633 | tovirt(r1,r1) | |
ca54502b | 634 | /* where the trap should return need -8 to adjust for rtsd r15, 8 */ |
b9ea77e2 | 635 | addik r15, r0, ret_from_exc-8 |
ca54502b MS |
636 | mfs r6, rear /* parameter unsigned long address */ |
637 | nop | |
638 | ori r7, r0, 0 /* parameter unsigned long error_code */ | |
9814cc11 MS |
639 | rted r0, do_page_fault |
640 | addik r5, r1, PTO /* parameter struct pt_regs * regs */ | |
ca54502b MS |
641 | |
642 | /* Entry point used to return from an exception. */ | |
643 | C_ENTRY(ret_from_exc): | |
77f6d226 | 644 | lwi r11, r1, PTO + PT_MODE; |
ca54502b MS |
645 | bnei r11, 2f; /* See if returning to kernel mode, */ |
646 | /* ... if so, skip resched &c. */ | |
647 | ||
648 | /* We're returning to user mode, so check for various conditions that | |
649 | trigger rescheduling. */ | |
b1d70c62 | 650 | lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */ |
ca54502b MS |
651 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
652 | andi r11, r11, _TIF_NEED_RESCHED; | |
653 | beqi r11, 5f; | |
654 | ||
655 | /* Call the scheduler before returning from a syscall/trap. */ | |
656 | bralid r15, schedule; /* Call scheduler */ | |
657 | nop; /* delay slot */ | |
658 | ||
659 | /* Maybe handle a signal */ | |
b1d70c62 | 660 | 5: lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */ |
ca54502b MS |
661 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
662 | andi r11, r11, _TIF_SIGPENDING; | |
663 | beqi r11, 1f; /* Signals to handle, handle them */ | |
664 | ||
665 | /* | |
666 | * Handle a signal return; Pending signals should be in r18. | |
667 | * | |
668 | * Not all registers are saved by the normal trap/interrupt entry | |
669 | * points (for instance, call-saved registers (because the normal | |
670 | * C-compiler calling sequence in the kernel makes sure they're | |
671 | * preserved), and call-clobbered registers in the case of | |
672 | * traps), but signal handlers may want to examine or change the | |
673 | * complete register state. Here we save anything not saved by | |
674 | * the normal entry sequence, so that it may be safely restored | |
36f60954 | 675 | * (in a possibly modified form) after do_signal returns. */ |
b9ea77e2 | 676 | addik r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ |
ca54502b MS |
677 | addi r7, r0, 0; /* Arg 3: int in_syscall */ |
678 | bralid r15, do_signal; /* Handle any signals */ | |
841d6e8c | 679 | add r6, r0, r0; /* Arg 2: sigset_t *oldset */ |
ca54502b MS |
680 | |
681 | /* Finally, return to user state. */ | |
96014cc3 | 682 | 1: set_bip; /* Ints masked for state restore */ |
8633bebc | 683 | swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */ |
ca54502b MS |
684 | VM_OFF; |
685 | tophys(r1,r1); | |
686 | ||
ca54502b MS |
687 | RESTORE_REGS; |
688 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ | |
689 | ||
690 | lwi r1, r1, PT_R1 - PT_SIZE; /* Restore user stack pointer. */ | |
691 | bri 6f; | |
692 | /* Return to kernel state. */ | |
96014cc3 MS |
693 | 2: set_bip; /* Ints masked for state restore */ |
694 | VM_OFF; | |
ca54502b | 695 | tophys(r1,r1); |
ca54502b MS |
696 | RESTORE_REGS; |
697 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ | |
698 | ||
699 | tovirt(r1,r1); | |
700 | 6: | |
701 | EXC_return: /* Make global symbol for debugging */ | |
702 | rtbd r14, 0; /* Instructions to return from an IRQ */ | |
703 | nop; | |
704 | ||
705 | /* | |
706 | * HW EXCEPTION rutine end | |
707 | */ | |
708 | ||
709 | /* | |
710 | * Hardware maskable interrupts. | |
711 | * | |
712 | * The stack-pointer (r1) should have already been saved to the memory | |
713 | * location PER_CPU(ENTRY_SP). | |
714 | */ | |
715 | C_ENTRY(_interrupt): | |
716 | /* MS: we are in physical address */ | |
717 | /* Save registers, switch to proper stack, convert SP to virtual.*/ | |
718 | swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) | |
ca54502b | 719 | /* MS: See if already in kernel mode. */ |
653e447e | 720 | mfs r1, rmsr |
5c0d72b1 | 721 | nop |
653e447e MS |
722 | andi r1, r1, MSR_UMS |
723 | bnei r1, 1f | |
ca54502b MS |
724 | |
725 | /* Kernel-mode state save. */ | |
653e447e MS |
726 | lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) |
727 | tophys(r1,r1); /* MS: I have in r1 physical address where stack is */ | |
ca54502b MS |
728 | /* save registers */ |
729 | /* MS: Make room on the stack -> activation record */ | |
730 | addik r1, r1, -STATE_SAVE_SIZE; | |
ca54502b | 731 | SAVE_REGS |
77f6d226 | 732 | swi r1, r1, PTO + PT_MODE; /* 0 - user mode, 1 - kernel mode */ |
ca54502b MS |
733 | brid 2f; |
734 | nop; /* MS: Fill delay slot */ | |
735 | ||
736 | 1: | |
737 | /* User-mode state save. */ | |
ca54502b MS |
738 | /* MS: get the saved current */ |
739 | lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); | |
740 | tophys(r1,r1); | |
741 | lwi r1, r1, TS_THREAD_INFO; | |
742 | addik r1, r1, THREAD_SIZE; | |
743 | tophys(r1,r1); | |
744 | /* save registers */ | |
745 | addik r1, r1, -STATE_SAVE_SIZE; | |
ca54502b MS |
746 | SAVE_REGS |
747 | /* calculate mode */ | |
748 | swi r0, r1, PTO + PT_MODE; | |
749 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); | |
750 | swi r11, r1, PTO+PT_R1; | |
ca54502b | 751 | 2: |
b1d70c62 | 752 | lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); |
ca54502b | 753 | tovirt(r1,r1) |
b9ea77e2 | 754 | addik r5, r1, PTO; |
ca54502b | 755 | set_vms; |
b9ea77e2 MS |
756 | addik r11, r0, do_IRQ; |
757 | addik r15, r0, irq_call; | |
ca54502b MS |
758 | irq_call:rtbd r11, 0; |
759 | nop; | |
760 | ||
761 | /* MS: we are in virtual mode */ | |
762 | ret_from_irq: | |
763 | lwi r11, r1, PTO + PT_MODE; | |
764 | bnei r11, 2f; | |
765 | ||
b1d70c62 | 766 | lwi r11, CURRENT_TASK, TS_THREAD_INFO; |
ca54502b MS |
767 | lwi r11, r11, TI_FLAGS; /* MS: get flags from thread info */ |
768 | andi r11, r11, _TIF_NEED_RESCHED; | |
769 | beqi r11, 5f | |
770 | bralid r15, schedule; | |
771 | nop; /* delay slot */ | |
772 | ||
773 | /* Maybe handle a signal */ | |
b1d70c62 | 774 | 5: lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* MS: get thread info */ |
ca54502b MS |
775 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
776 | andi r11, r11, _TIF_SIGPENDING; | |
777 | beqid r11, no_intr_resched | |
778 | /* Handle a signal return; Pending signals should be in r18. */ | |
779 | addi r7, r0, 0; /* Arg 3: int in_syscall */ | |
b9ea77e2 | 780 | addik r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ |
ca54502b MS |
781 | bralid r15, do_signal; /* Handle any signals */ |
782 | add r6, r0, r0; /* Arg 2: sigset_t *oldset */ | |
783 | ||
784 | /* Finally, return to user state. */ | |
785 | no_intr_resched: | |
786 | /* Disable interrupts, we are now committed to the state restore */ | |
787 | disable_irq | |
8633bebc | 788 | swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); |
ca54502b MS |
789 | VM_OFF; |
790 | tophys(r1,r1); | |
ca54502b MS |
791 | RESTORE_REGS |
792 | addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */ | |
793 | lwi r1, r1, PT_R1 - PT_SIZE; | |
794 | bri 6f; | |
795 | /* MS: Return to kernel state. */ | |
77753790 MS |
796 | 2: |
797 | #ifdef CONFIG_PREEMPT | |
b1d70c62 | 798 | lwi r11, CURRENT_TASK, TS_THREAD_INFO; |
77753790 MS |
799 | /* MS: get preempt_count from thread info */ |
800 | lwi r5, r11, TI_PREEMPT_COUNT; | |
801 | bgti r5, restore; | |
802 | ||
803 | lwi r5, r11, TI_FLAGS; /* get flags in thread info */ | |
804 | andi r5, r5, _TIF_NEED_RESCHED; | |
805 | beqi r5, restore /* if zero jump over */ | |
806 | ||
807 | preempt: | |
808 | /* interrupts are off that's why I am calling preempt_chedule_irq */ | |
809 | bralid r15, preempt_schedule_irq | |
810 | nop | |
b1d70c62 | 811 | lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */ |
77753790 MS |
812 | lwi r5, r11, TI_FLAGS; /* get flags in thread info */ |
813 | andi r5, r5, _TIF_NEED_RESCHED; | |
814 | bnei r5, preempt /* if non zero jump to resched */ | |
815 | restore: | |
816 | #endif | |
817 | VM_OFF /* MS: turn off MMU */ | |
ca54502b | 818 | tophys(r1,r1) |
ca54502b MS |
819 | RESTORE_REGS |
820 | addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */ | |
821 | tovirt(r1,r1); | |
822 | 6: | |
823 | IRQ_return: /* MS: Make global symbol for debugging */ | |
824 | rtid r14, 0 | |
825 | nop | |
826 | ||
827 | /* | |
828 | * `Debug' trap | |
829 | * We enter dbtrap in "BIP" (breakpoint) mode. | |
830 | * So we exit the breakpoint mode with an 'rtbd' and proceed with the | |
831 | * original dbtrap. | |
832 | * however, wait to save state first | |
833 | */ | |
834 | C_ENTRY(_debug_exception): | |
835 | /* BIP bit is set on entry, no interrupts can occur */ | |
836 | swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) | |
837 | ||
653e447e | 838 | mfs r1, rmsr |
5c0d72b1 | 839 | nop |
653e447e MS |
840 | andi r1, r1, MSR_UMS |
841 | bnei r1, 1f | |
ca54502b | 842 | /* Kernel-mode state save. */ |
653e447e MS |
843 | lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/ |
844 | tophys(r1,r1); | |
ca54502b MS |
845 | |
846 | addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ | |
ca54502b MS |
847 | SAVE_REGS; |
848 | ||
77f6d226 | 849 | swi r1, r1, PTO + PT_MODE; |
ca54502b MS |
850 | brid 2f; |
851 | nop; /* Fill delay slot */ | |
852 | 1: /* User-mode state save. */ | |
ca54502b MS |
853 | lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */ |
854 | tophys(r1,r1); | |
855 | lwi r1, r1, TS_THREAD_INFO; /* get the thread info */ | |
856 | addik r1, r1, THREAD_SIZE; /* calculate kernel stack pointer */ | |
857 | tophys(r1,r1); | |
858 | ||
859 | addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ | |
ca54502b MS |
860 | SAVE_REGS; |
861 | ||
77f6d226 | 862 | swi r0, r1, PTO + PT_MODE; /* Was in user-mode. */ |
ca54502b MS |
863 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); |
864 | swi r11, r1, PTO+PT_R1; /* Store user SP. */ | |
653e447e | 865 | 2: |
ca54502b MS |
866 | tovirt(r1,r1) |
867 | ||
06b28640 | 868 | set_vms; |
ca54502b MS |
869 | addi r5, r0, SIGTRAP /* send the trap signal */ |
870 | add r6, r0, CURRENT_TASK; /* Get current task ptr into r11 */ | |
871 | addk r7, r0, r0 /* 3rd param zero */ | |
06b28640 | 872 | dbtrap_call: rtbd r0, send_sig; |
b9ea77e2 | 873 | addik r15, r0, dbtrap_call; |
ca54502b MS |
874 | |
875 | set_bip; /* Ints masked for state restore*/ | |
77f6d226 | 876 | lwi r11, r1, PTO + PT_MODE; |
ca54502b MS |
877 | bnei r11, 2f; |
878 | ||
879 | /* Get current task ptr into r11 */ | |
b1d70c62 | 880 | lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */ |
ca54502b MS |
881 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
882 | andi r11, r11, _TIF_NEED_RESCHED; | |
883 | beqi r11, 5f; | |
884 | ||
885 | /* Call the scheduler before returning from a syscall/trap. */ | |
886 | ||
887 | bralid r15, schedule; /* Call scheduler */ | |
888 | nop; /* delay slot */ | |
889 | /* XXX Is PT_DTRACE handling needed here? */ | |
890 | /* XXX m68knommu also checks TASK_STATE & TASK_COUNTER here. */ | |
891 | ||
892 | /* Maybe handle a signal */ | |
b1d70c62 | 893 | 5: lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */ |
ca54502b MS |
894 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
895 | andi r11, r11, _TIF_SIGPENDING; | |
896 | beqi r11, 1f; /* Signals to handle, handle them */ | |
897 | ||
898 | /* Handle a signal return; Pending signals should be in r18. */ | |
899 | /* Not all registers are saved by the normal trap/interrupt entry | |
900 | points (for instance, call-saved registers (because the normal | |
901 | C-compiler calling sequence in the kernel makes sure they're | |
902 | preserved), and call-clobbered registers in the case of | |
903 | traps), but signal handlers may want to examine or change the | |
904 | complete register state. Here we save anything not saved by | |
905 | the normal entry sequence, so that it may be safely restored | |
906 | (in a possibly modified form) after do_signal returns. */ | |
907 | ||
b9ea77e2 | 908 | addik r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ |
ca54502b MS |
909 | addi r7, r0, 0; /* Arg 3: int in_syscall */ |
910 | bralid r15, do_signal; /* Handle any signals */ | |
841d6e8c | 911 | add r6, r0, r0; /* Arg 2: sigset_t *oldset */ |
ca54502b MS |
912 | |
913 | ||
914 | /* Finally, return to user state. */ | |
5c0d72b1 | 915 | 1: |
8633bebc | 916 | swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */ |
ca54502b MS |
917 | VM_OFF; |
918 | tophys(r1,r1); | |
919 | ||
ca54502b MS |
920 | RESTORE_REGS |
921 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ | |
922 | ||
923 | ||
924 | lwi r1, r1, PT_R1 - PT_SIZE; | |
925 | /* Restore user stack pointer. */ | |
926 | bri 6f; | |
927 | ||
928 | /* Return to kernel state. */ | |
929 | 2: VM_OFF; | |
930 | tophys(r1,r1); | |
ca54502b MS |
931 | RESTORE_REGS |
932 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ | |
933 | ||
934 | tovirt(r1,r1); | |
935 | 6: | |
936 | DBTRAP_return: /* Make global symbol for debugging */ | |
937 | rtbd r14, 0; /* Instructions to return from an IRQ */ | |
938 | nop; | |
939 | ||
940 | ||
941 | ||
942 | ENTRY(_switch_to) | |
943 | /* prepare return value */ | |
b1d70c62 | 944 | addk r3, r0, CURRENT_TASK |
ca54502b MS |
945 | |
946 | /* save registers in cpu_context */ | |
947 | /* use r11 and r12, volatile registers, as temp register */ | |
948 | /* give start of cpu_context for previous process */ | |
949 | addik r11, r5, TI_CPU_CONTEXT | |
950 | swi r1, r11, CC_R1 | |
951 | swi r2, r11, CC_R2 | |
952 | /* skip volatile registers. | |
953 | * they are saved on stack when we jumped to _switch_to() */ | |
954 | /* dedicated registers */ | |
955 | swi r13, r11, CC_R13 | |
956 | swi r14, r11, CC_R14 | |
957 | swi r15, r11, CC_R15 | |
958 | swi r16, r11, CC_R16 | |
959 | swi r17, r11, CC_R17 | |
960 | swi r18, r11, CC_R18 | |
961 | /* save non-volatile registers */ | |
962 | swi r19, r11, CC_R19 | |
963 | swi r20, r11, CC_R20 | |
964 | swi r21, r11, CC_R21 | |
965 | swi r22, r11, CC_R22 | |
966 | swi r23, r11, CC_R23 | |
967 | swi r24, r11, CC_R24 | |
968 | swi r25, r11, CC_R25 | |
969 | swi r26, r11, CC_R26 | |
970 | swi r27, r11, CC_R27 | |
971 | swi r28, r11, CC_R28 | |
972 | swi r29, r11, CC_R29 | |
973 | swi r30, r11, CC_R30 | |
974 | /* special purpose registers */ | |
975 | mfs r12, rmsr | |
976 | nop | |
977 | swi r12, r11, CC_MSR | |
978 | mfs r12, rear | |
979 | nop | |
980 | swi r12, r11, CC_EAR | |
981 | mfs r12, resr | |
982 | nop | |
983 | swi r12, r11, CC_ESR | |
984 | mfs r12, rfsr | |
985 | nop | |
986 | swi r12, r11, CC_FSR | |
987 | ||
b1d70c62 MS |
988 | /* update r31, the current-give me pointer to task which will be next */ |
989 | lwi CURRENT_TASK, r6, TI_TASK | |
ca54502b | 990 | /* stored it to current_save too */ |
b1d70c62 | 991 | swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE) |
ca54502b MS |
992 | |
993 | /* get new process' cpu context and restore */ | |
994 | /* give me start where start context of next task */ | |
995 | addik r11, r6, TI_CPU_CONTEXT | |
996 | ||
997 | /* non-volatile registers */ | |
998 | lwi r30, r11, CC_R30 | |
999 | lwi r29, r11, CC_R29 | |
1000 | lwi r28, r11, CC_R28 | |
1001 | lwi r27, r11, CC_R27 | |
1002 | lwi r26, r11, CC_R26 | |
1003 | lwi r25, r11, CC_R25 | |
1004 | lwi r24, r11, CC_R24 | |
1005 | lwi r23, r11, CC_R23 | |
1006 | lwi r22, r11, CC_R22 | |
1007 | lwi r21, r11, CC_R21 | |
1008 | lwi r20, r11, CC_R20 | |
1009 | lwi r19, r11, CC_R19 | |
1010 | /* dedicated registers */ | |
1011 | lwi r18, r11, CC_R18 | |
1012 | lwi r17, r11, CC_R17 | |
1013 | lwi r16, r11, CC_R16 | |
1014 | lwi r15, r11, CC_R15 | |
1015 | lwi r14, r11, CC_R14 | |
1016 | lwi r13, r11, CC_R13 | |
1017 | /* skip volatile registers */ | |
1018 | lwi r2, r11, CC_R2 | |
1019 | lwi r1, r11, CC_R1 | |
1020 | ||
1021 | /* special purpose registers */ | |
1022 | lwi r12, r11, CC_FSR | |
1023 | mts rfsr, r12 | |
1024 | nop | |
1025 | lwi r12, r11, CC_MSR | |
1026 | mts rmsr, r12 | |
1027 | nop | |
1028 | ||
1029 | rtsd r15, 8 | |
1030 | nop | |
1031 | ||
1032 | ENTRY(_reset) | |
1033 | brai 0x70; /* Jump back to FS-boot */ | |
1034 | ||
1035 | ENTRY(_break) | |
1036 | mfs r5, rmsr | |
1037 | nop | |
1038 | swi r5, r0, 0x250 + TOPHYS(r0_ram) | |
1039 | mfs r5, resr | |
1040 | nop | |
1041 | swi r5, r0, 0x254 + TOPHYS(r0_ram) | |
1042 | bri 0 | |
1043 | ||
1044 | /* These are compiled and loaded into high memory, then | |
1045 | * copied into place in mach_early_setup */ | |
1046 | .section .init.ivt, "ax" | |
1047 | .org 0x0 | |
1048 | /* this is very important - here is the reset vector */ | |
1049 | /* in current MMU branch you don't care what is here - it is | |
1050 | * used from bootloader site - but this is correct for FS-BOOT */ | |
1051 | brai 0x70 | |
1052 | nop | |
1053 | brai TOPHYS(_user_exception); /* syscall handler */ | |
1054 | brai TOPHYS(_interrupt); /* Interrupt handler */ | |
1055 | brai TOPHYS(_break); /* nmi trap handler */ | |
1056 | brai TOPHYS(_hw_exception_handler); /* HW exception handler */ | |
1057 | ||
1058 | .org 0x60 | |
1059 | brai TOPHYS(_debug_exception); /* debug trap handler*/ | |
1060 | ||
1061 | .section .rodata,"a" | |
1062 | #include "syscall_table.S" | |
1063 | ||
1064 | syscall_table_size=(.-sys_call_table) | |
1065 | ||
ce3266c0 SM |
1066 | type_SYSCALL: |
1067 | .ascii "SYSCALL\0" | |
1068 | type_IRQ: | |
1069 | .ascii "IRQ\0" | |
1070 | type_IRQ_PREEMPT: | |
1071 | .ascii "IRQ (PREEMPTED)\0" | |
1072 | type_SYSCALL_PREEMPT: | |
1073 | .ascii " SYSCALL (PREEMPTED)\0" | |
1074 | ||
1075 | /* | |
1076 | * Trap decoding for stack unwinder | |
1077 | * Tuples are (start addr, end addr, string) | |
1078 | * If return address lies on [start addr, end addr], | |
1079 | * unwinder displays 'string' | |
1080 | */ | |
1081 | ||
1082 | .align 4 | |
1083 | .global microblaze_trap_handlers | |
1084 | microblaze_trap_handlers: | |
1085 | /* Exact matches come first */ | |
1086 | .word ret_from_trap; .word ret_from_trap ; .word type_SYSCALL | |
1087 | .word ret_from_irq ; .word ret_from_irq ; .word type_IRQ | |
1088 | /* Fuzzy matches go here */ | |
1089 | .word ret_from_irq ; .word no_intr_resched ; .word type_IRQ_PREEMPT | |
1090 | .word ret_from_trap; .word TRAP_return ; .word type_SYSCALL_PREEMPT | |
1091 | /* End of table */ | |
1092 | .word 0 ; .word 0 ; .word 0 |