1 /* SPDX-License-Identifier: GPL-2.0-or-later * <<
2 /* 1 /*
3 * OpenRISC entry.S !! 2 * This file is subject to the terms and conditions of the GNU General Public
4 * !! 3 * License. See the file "COPYING" in the main directory of this archive
5 * Linux architectural port borrowing liberall !! 4 * for more details.
6 * others. All original copyrights apply as p !! 5 *
7 * declaration. !! 6 * Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
8 * !! 7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9 * Modifications for the OpenRISC architecture !! 8 * Copyright (C) 2001 MIPS Technologies, Inc.
10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@ !! 9 */
11 * Copyright (C) 2005 Gyorgy Jeney <nog@bsemi.c !! 10
12 * Copyright (C) 2010-2011 Jonas Bonn <jonas@so !! 11 #include <asm/asm.h>
13 */ !! 12 #include <asm/asmmacro.h>
14 !! 13 #include <asm/compiler.h>
15 #include <linux/linkage.h> !! 14 #include <asm/irqflags.h>
16 #include <linux/pgtable.h> !! 15 #include <asm/regdef.h>
17 !! 16 #include <asm/mipsregs.h>
18 #include <asm/processor.h> !! 17 #include <asm/stackframe.h>
19 #include <asm/unistd.h> !! 18 #include <asm/isadep.h>
20 #include <asm/thread_info.h> 19 #include <asm/thread_info.h>
21 #include <asm/errno.h> !! 20 #include <asm/war.h>
22 #include <asm/spr_defs.h> <<
23 #include <asm/page.h> <<
24 #include <asm/mmu.h> <<
25 #include <asm/asm-offsets.h> <<
26 <<
27 #define DISABLE_INTERRUPTS(t1,t2) <<
28 l.mfspr t2,r0,SPR_SR <<
29 l.movhi t1,hi(~(SPR_SR_IEE|SPR_SR_TEE) <<
30 l.ori t1,t1,lo(~(SPR_SR_IEE|SPR_SR_T <<
31 l.and t2,t2,t1 <<
32 l.mtspr r0,t2,SPR_SR <<
33 <<
34 #define ENABLE_INTERRUPTS(t1) <<
35 l.mfspr t1,r0,SPR_SR <<
36 l.ori t1,t1,lo(SPR_SR_IEE|SPR_SR_TEE <<
37 l.mtspr r0,t1,SPR_SR <<
38 <<
39 /* =========================================== <<
40 21
41 #ifdef CONFIG_TRACE_IRQFLAGS !! 22 #ifndef CONFIG_PREEMPT
42 /* !! 23 #define resume_kernel restore_all
43 * Trace irq on/off creating a stack frame. <<
44 */ <<
45 #define TRACE_IRQS_OP(trace_op) <<
46 l.sw -8(r1),r2 /* store frame <<
47 l.sw -4(r1),r9 /* store retur <<
48 l.addi r2,r1,0 /* move sp to <<
49 l.jal trace_op <<
50 l.addi r1,r1,-8 <<
51 l.ori r1,r2,0 /* restore sp <<
52 l.lwz r9,-4(r1) /* restore ret <<
53 l.lwz r2,-8(r1) /* restore fp <<
54 /* <<
55 * Trace irq on/off and save registers we need <<
56 * clobbered. <<
57 */ <<
58 #define TRACE_IRQS_SAVE(t1,trace_op) <<
59 l.sw -12(r1),t1 /* save extra <<
60 l.sw -8(r1),r2 /* store frame <<
61 l.sw -4(r1),r9 /* store retur <<
62 l.addi r2,r1,0 /* move sp to <<
63 l.jal trace_op <<
64 l.addi r1,r1,-12 <<
65 l.ori r1,r2,0 /* restore sp <<
66 l.lwz r9,-4(r1) /* restore ret <<
67 l.lwz r2,-8(r1) /* restore fp <<
68 l.lwz t1,-12(r1) /* restore ext <<
69 <<
70 #define TRACE_IRQS_OFF TRACE_IRQS_OP(trace_ha <<
71 #define TRACE_IRQS_ON TRACE_IRQS_OP(trace_ha <<
72 #define TRACE_IRQS_ON_SYSCALL <<
73 TRACE_IRQS_SAVE(r10,trace_hardirqs_on) <<
74 l.lwz r3,PT_GPR3(r1) <<
75 l.lwz r4,PT_GPR4(r1) <<
76 l.lwz r5,PT_GPR5(r1) <<
77 l.lwz r6,PT_GPR6(r1) <<
78 l.lwz r7,PT_GPR7(r1) <<
79 l.lwz r8,PT_GPR8(r1) <<
80 l.lwz r11,PT_GPR11(r1) <<
81 #define TRACE_IRQS_OFF_ENTRY <<
82 l.lwz r5,PT_SR(r1) <<
83 l.andi r3,r5,(SPR_SR_IEE|SPR_SR_TEE) <<
84 l.sfeq r5,r0 /* skip trace <<
85 l.bf 1f <<
86 l.nop <<
87 TRACE_IRQS_SAVE(r4,trace_hardirqs_off) <<
88 1: <<
89 #else 24 #else
90 #define TRACE_IRQS_OFF !! 25 #define __ret_from_irq ret_from_exception
91 #define TRACE_IRQS_ON <<
92 #define TRACE_IRQS_OFF_ENTRY <<
93 #define TRACE_IRQS_ON_SYSCALL <<
94 #endif 26 #endif
95 27
96 /* !! 28 .text
97 * We need to disable interrupts at beginning !! 29 .align 5
98 * since interrupt might come in after we've l !! 30 #ifndef CONFIG_PREEMPT
99 * and overwrite EPC with address somewhere in !! 31 FEXPORT(ret_from_exception)
100 * which is of course wrong! !! 32 local_irq_disable # preempt stop
101 */ !! 33 b __ret_from_irq
102 !! 34 #endif
103 #define RESTORE_ALL !! 35 FEXPORT(ret_from_irq)
104 DISABLE_INTERRUPTS(r3,r4) !! 36 LONG_S s0, TI_REGS($28)
105 l.lwz r3,PT_PC(r1) !! 37 FEXPORT(__ret_from_irq)
106 l.mtspr r0,r3,SPR_EPCR_BASE !! 38 /*
107 l.lwz r3,PT_SR(r1) !! 39 * We can be coming here from a syscall done in the kernel space,
108 l.mtspr r0,r3,SPR_ESR_BASE !! 40 * e.g. a failed kernel_execve().
109 l.lwz r2,PT_GPR2(r1) !! 41 */
110 l.lwz r3,PT_GPR3(r1) !! 42 resume_userspace_check:
111 l.lwz r4,PT_GPR4(r1) !! 43 LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
112 l.lwz r5,PT_GPR5(r1) !! 44 andi t0, t0, KU_USER
113 l.lwz r6,PT_GPR6(r1) !! 45 beqz t0, resume_kernel
114 l.lwz r7,PT_GPR7(r1) !! 46
115 l.lwz r8,PT_GPR8(r1) !! 47 resume_userspace:
116 l.lwz r9,PT_GPR9(r1) !! 48 local_irq_disable # make sure we dont miss an
117 l.lwz r10,PT_GPR10(r1) !! 49 # interrupt setting need_resched
118 l.lwz r11,PT_GPR11(r1) !! 50 # between sampling and return
119 l.lwz r12,PT_GPR12(r1) !! 51 LONG_L a2, TI_FLAGS($28) # current->work
120 l.lwz r13,PT_GPR13(r1) !! 52 andi t0, a2, _TIF_WORK_MASK # (ignoring syscall_trace)
121 l.lwz r14,PT_GPR14(r1) !! 53 bnez t0, work_pending
122 l.lwz r15,PT_GPR15(r1) !! 54 j restore_all
123 l.lwz r16,PT_GPR16(r1) !! 55
124 l.lwz r17,PT_GPR17(r1) !! 56 #ifdef CONFIG_PREEMPT
125 l.lwz r18,PT_GPR18(r1) !! 57 resume_kernel:
126 l.lwz r19,PT_GPR19(r1) !! 58 local_irq_disable
127 l.lwz r20,PT_GPR20(r1) !! 59 lw t0, TI_PRE_COUNT($28)
128 l.lwz r21,PT_GPR21(r1) !! 60 bnez t0, restore_all
129 l.lwz r22,PT_GPR22(r1) !! 61 need_resched:
130 l.lwz r23,PT_GPR23(r1) !! 62 LONG_L t0, TI_FLAGS($28)
131 l.lwz r24,PT_GPR24(r1) !! 63 andi t1, t0, _TIF_NEED_RESCHED
132 l.lwz r25,PT_GPR25(r1) !! 64 beqz t1, restore_all
133 l.lwz r26,PT_GPR26(r1) !! 65 LONG_L t0, PT_STATUS(sp) # Interrupts off?
134 l.lwz r27,PT_GPR27(r1) !! 66 andi t0, 1
135 l.lwz r28,PT_GPR28(r1) !! 67 beqz t0, restore_all
136 l.lwz r29,PT_GPR29(r1) !! 68 jal preempt_schedule_irq
137 l.lwz r30,PT_GPR30(r1) !! 69 b need_resched
138 l.lwz r31,PT_GPR31(r1) !! 70 #endif
139 l.lwz r1,PT_SP(r1) !! 71
140 l.rfe !! 72 FEXPORT(ret_from_kernel_thread)
141 !! 73 jal schedule_tail # a0 = struct task_struct *prev
142 !! 74 move a0, s1
143 #define EXCEPTION_ENTRY(handler) !! 75 jal s0
144 .global handler !! 76 j syscall_exit
145 handler: !! 77
146 /* r1, EPCR, ESR a already saved */ !! 78 FEXPORT(ret_from_fork)
147 l.sw PT_GPR2(r1),r2 !! 79 jal schedule_tail # a0 = struct task_struct *prev
148 l.sw PT_GPR3(r1),r3 !! 80
149 /* r4 already save */ !! 81 FEXPORT(syscall_exit)
150 l.sw PT_GPR5(r1),r5 !! 82 #ifdef CONFIG_DEBUG_RSEQ
151 l.sw PT_GPR6(r1),r6 !! 83 move a0, sp
152 l.sw PT_GPR7(r1),r7 !! 84 jal rseq_syscall
153 l.sw PT_GPR8(r1),r8 !! 85 #endif
154 l.sw PT_GPR9(r1),r9 !! 86 local_irq_disable # make sure need_resched and
155 /* r10 already saved */ !! 87 # signals dont change between
156 l.sw PT_GPR11(r1),r11 !! 88 # sampling and return
157 /* r12 already saved */ !! 89 LONG_L a2, TI_FLAGS($28) # current->work
158 l.sw PT_GPR13(r1),r13 !! 90 li t0, _TIF_ALLWORK_MASK
159 l.sw PT_GPR14(r1),r14 !! 91 and t0, a2, t0
160 l.sw PT_GPR15(r1),r15 !! 92 bnez t0, syscall_exit_work
161 l.sw PT_GPR16(r1),r16 !! 93
162 l.sw PT_GPR17(r1),r17 !! 94 restore_all: # restore full frame
163 l.sw PT_GPR18(r1),r18 !! 95 .set noat
164 l.sw PT_GPR19(r1),r19 !! 96 RESTORE_TEMP
165 l.sw PT_GPR20(r1),r20 !! 97 RESTORE_AT
166 l.sw PT_GPR21(r1),r21 !! 98 RESTORE_STATIC
167 l.sw PT_GPR22(r1),r22 !! 99 restore_partial: # restore partial frame
168 l.sw PT_GPR23(r1),r23 !! 100 #ifdef CONFIG_TRACE_IRQFLAGS
169 l.sw PT_GPR24(r1),r24 !! 101 SAVE_STATIC
170 l.sw PT_GPR25(r1),r25 !! 102 SAVE_AT
171 l.sw PT_GPR26(r1),r26 !! 103 SAVE_TEMP
172 l.sw PT_GPR27(r1),r27 !! 104 LONG_L v0, PT_STATUS(sp)
173 l.sw PT_GPR28(r1),r28 !! 105 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
174 l.sw PT_GPR29(r1),r29 !! 106 and v0, ST0_IEP
175 /* r30 already save */ <<
176 l.sw PT_GPR31(r1),r31 <<
177 TRACE_IRQS_OFF_ENTRY <<
178 /* Store -1 in orig_gpr11 for non-sysc <<
179 l.addi r30,r0,-1 <<
180 l.sw PT_ORIG_GPR11(r1),r30 <<
181 <<
182 #define UNHANDLED_EXCEPTION(handler,vector) <<
183 .global handler <<
184 handler: <<
185 /* r1, EPCR, ESR already saved */ <<
186 l.sw PT_GPR2(r1),r2 <<
187 l.sw PT_GPR3(r1),r3 <<
188 l.sw PT_GPR5(r1),r5 <<
189 l.sw PT_GPR6(r1),r6 <<
190 l.sw PT_GPR7(r1),r7 <<
191 l.sw PT_GPR8(r1),r8 <<
192 l.sw PT_GPR9(r1),r9 <<
193 /* r10 already saved */ <<
194 l.sw PT_GPR11(r1),r11 <<
195 /* r12 already saved */ <<
196 l.sw PT_GPR13(r1),r13 <<
197 l.sw PT_GPR14(r1),r14 <<
198 l.sw PT_GPR15(r1),r15 <<
199 l.sw PT_GPR16(r1),r16 <<
200 l.sw PT_GPR17(r1),r17 <<
201 l.sw PT_GPR18(r1),r18 <<
202 l.sw PT_GPR19(r1),r19 <<
203 l.sw PT_GPR20(r1),r20 <<
204 l.sw PT_GPR21(r1),r21 <<
205 l.sw PT_GPR22(r1),r22 <<
206 l.sw PT_GPR23(r1),r23 <<
207 l.sw PT_GPR24(r1),r24 <<
208 l.sw PT_GPR25(r1),r25 <<
209 l.sw PT_GPR26(r1),r26 <<
210 l.sw PT_GPR27(r1),r27 <<
211 l.sw PT_GPR28(r1),r28 <<
212 l.sw PT_GPR29(r1),r29 <<
213 /* r30 already saved */ <<
214 l.sw PT_GPR31(r1),r31 <<
215 /* Store -1 in orig_gpr11 for non-sysc <<
216 l.addi r30,r0,-1 <<
217 l.sw PT_ORIG_GPR11(r1),r30 <<
218 l.addi r3,r1,0 <<
219 /* r4 is exception EA */ <<
220 l.addi r5,r0,vector <<
221 l.jal unhandled_exception <<
222 l.nop <<
223 l.j _ret_from_exception <<
224 l.nop <<
225 <<
226 /* clobbers 'reg' */ <<
227 #define CLEAR_LWA_FLAG(reg) \ <<
228 l.movhi reg,hi(lwa_flag) ;\ <<
229 l.ori reg,reg,lo(lwa_flag) ;\ <<
230 l.sw 0(reg),r0 <<
231 /* <<
232 * NOTE: one should never assume that SPR_EPC, <<
233 * contain the same values as when excep <<
234 * occured. in fact they never do. if yo <<
235 * values saved on stack (for SPR_EPC, S <<
236 * of r4 (for SPR_EEAR). for details loo <<
237 * in 'arch/openrisc/kernel/head.S' <<
238 */ <<
239 <<
240 /* =========================================== <<
241 <<
242 /* ---[ 0x100: RESET exception ]-------------- <<
243 <<
244 EXCEPTION_ENTRY(_tng_kernel_start) <<
245 l.jal _start <<
246 l.andi r0,r0,0 <<
247 <<
248 /* ---[ 0x200: BUS exception ]---------------- <<
249 <<
250 EXCEPTION_ENTRY(_bus_fault_handler) <<
251 CLEAR_LWA_FLAG(r3) <<
252 /* r4: EA of fault (set by EXCEPTION_H <<
253 l.jal do_bus_fault <<
254 l.addi r3,r1,0 /* pt_regs */ <<
255 <<
256 l.j _ret_from_exception <<
257 l.nop <<
258 <<
259 /* ---[ 0x300: Data Page Fault exception ]---- <<
260 EXCEPTION_ENTRY(_dtlb_miss_page_fault_handler) <<
261 CLEAR_LWA_FLAG(r3) <<
262 l.and r5,r5,r0 <<
263 l.j 1f <<
264 l.nop <<
265 <<
266 EXCEPTION_ENTRY(_data_page_fault_handler) <<
267 CLEAR_LWA_FLAG(r3) <<
268 /* set up parameters for do_page_fault <<
269 l.ori r5,r0,0x300 // <<
270 1: <<
271 l.addi r3,r1,0 // <<
272 /* r4 set be EXCEPTION_HANDLE */ // <<
273 <<
274 #ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX <<
275 l.lwz r6,PT_PC(r3) // <<
276 l.lwz r6,0(r6) // <<
277 <<
278 l.srli r6,r6,26 // <<
279 l.sfeqi r6,0 // <<
280 l.bf 8f <<
281 l.sfeqi r6,1 // <<
282 l.bf 8f <<
283 l.sfeqi r6,3 // <<
284 l.bf 8f <<
285 l.sfeqi r6,4 // <<
286 l.bf 8f <<
287 l.sfeqi r6,0x11 // <<
288 l.bf 8f <<
289 l.sfeqi r6,0x12 // <<
290 l.bf 8f <<
291 l.nop <<
292 <<
293 l.j 9f <<
294 l.nop <<
295 <<
296 8: // offending insn is in delay slot <<
297 l.lwz r6,PT_PC(r3) // <<
298 l.addi r6,r6,4 <<
299 l.lwz r6,0(r6) // <<
300 l.srli r6,r6,26 // <<
301 9: // offending instruction opcode loaded in r <<
302 <<
303 #else 107 #else
304 !! 108 and v0, ST0_IE
305 l.mfspr r6,r0,SPR_SR // <<
306 l.andi r6,r6,SPR_SR_DSX // <<
307 l.sfne r6,r0 // <<
308 l.bnf 7f <<
309 l.lwz r6,PT_PC(r3) // <<
310 <<
311 l.addi r6,r6,4 // <<
312 7: <<
313 l.lwz r6,0(r6) // <<
314 l.srli r6,r6,26 // <<
315 #endif 109 #endif
316 !! 110 beqz v0, 1f
317 l.sfgeui r6,0x33 // !! 111 jal trace_hardirqs_on
318 l.bnf 1f !! 112 b 2f
319 l.sfleui r6,0x37 !! 113 1: jal trace_hardirqs_off
320 l.bnf 1f <<
321 l.ori r6,r0,0x1 // <<
322 l.j 2f <<
323 l.nop <<
324 1: l.ori r6,r0,0x0 // <<
325 2: 114 2:
326 !! 115 RESTORE_TEMP
327 /* call fault.c handler in openrisc/mm !! 116 RESTORE_AT
328 l.jal do_page_fault !! 117 RESTORE_STATIC
329 l.nop !! 118 #endif
330 l.j _ret_from_exception !! 119 RESTORE_SOME
331 l.nop !! 120 RESTORE_SP_AND_RET
332 !! 121 .set at
333 /* ---[ 0x400: Insn Page Fault exception ]---- !! 122
334 EXCEPTION_ENTRY(_itlb_miss_page_fault_handler) !! 123 work_pending:
335 CLEAR_LWA_FLAG(r3) !! 124 andi t0, a2, _TIF_NEED_RESCHED # a2 is preloaded with TI_FLAGS
336 l.and r5,r5,r0 !! 125 beqz t0, work_notifysig
337 l.j 1f !! 126 work_resched:
338 l.nop <<
339 <<
340 EXCEPTION_ENTRY(_insn_page_fault_handler) <<
341 CLEAR_LWA_FLAG(r3) <<
342 /* set up parameters for do_page_fault <<
343 l.ori r5,r0,0x400 // <<
344 1: <<
345 l.addi r3,r1,0 // <<
346 /* r4 set be EXCEPTION_HANDLE */ // <<
347 l.ori r6,r0,0x0 // <<
348 <<
349 /* call fault.c handler in openrisc/mm <<
350 l.jal do_page_fault <<
351 l.nop <<
352 l.j _ret_from_exception <<
353 l.nop <<
354 <<
355 <<
356 /* ---[ 0x500: Timer exception ]-------------- <<
357 <<
358 EXCEPTION_ENTRY(_timer_handler) <<
359 CLEAR_LWA_FLAG(r3) <<
360 l.jal timer_interrupt <<
361 l.addi r3,r1,0 /* pt_regs */ <<
362 <<
363 l.j _ret_from_intr <<
364 l.nop <<
365 <<
366 /* ---[ 0x600: Alignment exception ]---------- <<
367 <<
368 EXCEPTION_ENTRY(_alignment_handler) <<
369 CLEAR_LWA_FLAG(r3) <<
370 /* r4: EA of fault (set by EXCEPTION_H <<
371 l.jal do_unaligned_access <<
372 l.addi r3,r1,0 /* pt_regs */ <<
373 <<
374 l.j _ret_from_exception <<
375 l.nop <<
376 <<
377 #if 0 <<
378 EXCEPTION_ENTRY(_alignment_handler) <<
379 // l.mfspr r2,r0,SPR_EEAR_BASE /* L <<
380 l.addi r2,r4,0 <<
381 // l.mfspr r5,r0,SPR_EPCR_BASE /* L <<
382 l.lwz r5,PT_PC(r1) <<
383 <<
384 l.lwz r3,0(r5) /* Loa <<
385 l.srli r4,r3,26 /* Shi <<
386 <<
387 l.sfeqi r4,0x00 /* Che <<
388 l.bf jmp <<
389 l.sfeqi r4,0x01 <<
390 l.bf jmp <<
391 l.sfeqi r4,0x03 <<
392 l.bf jmp <<
393 l.sfeqi r4,0x04 <<
394 l.bf jmp <<
395 l.sfeqi r4,0x11 <<
396 l.bf jr <<
397 l.sfeqi r4,0x12 <<
398 l.bf jr <<
399 l.nop <<
400 l.j 1f <<
401 l.addi r5,r5,4 /* Inc <<
402 <<
403 jmp: <<
404 l.slli r4,r3,6 /* Get <<
405 l.srai r4,r4,4 <<
406 <<
407 l.lwz r3,4(r5) /* Loa <<
408 <<
409 l.add r5,r5,r4 /* Cal <<
410 <<
411 l.j 1f <<
412 l.srli r4,r3,26 /* Shi <<
413 <<
414 jr: <<
415 l.slli r4,r3,9 /* Shi <<
416 l.andi r4,r4,0x7c <<
417 <<
418 l.lwz r3,4(r5) /* Loa <<
419 <<
420 l.add r4,r4,r1 /* Loa <<
421 l.lwz r5,0(r4) <<
422 <<
423 l.srli r4,r3,26 /* Shi <<
424 <<
425 <<
426 1: <<
427 // l.mtspr r0,r5,SPR_EPCR_BASE <<
428 l.sw PT_PC(r1),r5 <<
429 <<
430 l.sfeqi r4,0x26 <<
431 l.bf lhs <<
432 l.sfeqi r4,0x25 <<
433 l.bf lhz <<
434 l.sfeqi r4,0x22 <<
435 l.bf lws <<
436 l.sfeqi r4,0x21 <<
437 l.bf lwz <<
438 l.sfeqi r4,0x37 <<
439 l.bf sh <<
440 l.sfeqi r4,0x35 <<
441 l.bf sw <<
442 l.nop <<
443 <<
444 1: l.j 1b /* I d <<
445 l.nop <<
446 <<
447 lhs: l.lbs r5,0(r2) <<
448 l.slli r5,r5,8 <<
449 l.lbz r6,1(r2) <<
450 l.or r5,r5,r6 <<
451 l.srli r4,r3,19 <<
452 l.andi r4,r4,0x7c <<
453 l.add r4,r4,r1 <<
454 l.j align_end <<
455 l.sw 0(r4),r5 <<
456 <<
457 lhz: l.lbz r5,0(r2) <<
458 l.slli r5,r5,8 <<
459 l.lbz r6,1(r2) <<
460 l.or r5,r5,r6 <<
461 l.srli r4,r3,19 <<
462 l.andi r4,r4,0x7c <<
463 l.add r4,r4,r1 <<
464 l.j align_end <<
465 l.sw 0(r4),r5 <<
466 <<
467 lws: l.lbs r5,0(r2) <<
468 l.slli r5,r5,24 <<
469 l.lbz r6,1(r2) <<
470 l.slli r6,r6,16 <<
471 l.or r5,r5,r6 <<
472 l.lbz r6,2(r2) <<
473 l.slli r6,r6,8 <<
474 l.or r5,r5,r6 <<
475 l.lbz r6,3(r2) <<
476 l.or r5,r5,r6 <<
477 l.srli r4,r3,19 <<
478 l.andi r4,r4,0x7c <<
479 l.add r4,r4,r1 <<
480 l.j align_end <<
481 l.sw 0(r4),r5 <<
482 <<
483 lwz: l.lbz r5,0(r2) <<
484 l.slli r5,r5,24 <<
485 l.lbz r6,1(r2) <<
486 l.slli r6,r6,16 <<
487 l.or r5,r5,r6 <<
488 l.lbz r6,2(r2) <<
489 l.slli r6,r6,8 <<
490 l.or r5,r5,r6 <<
491 l.lbz r6,3(r2) <<
492 l.or r5,r5,r6 <<
493 l.srli r4,r3,19 <<
494 l.andi r4,r4,0x7c <<
495 l.add r4,r4,r1 <<
496 l.j align_end <<
497 l.sw 0(r4),r5 <<
498 <<
499 sh: <<
500 l.srli r4,r3,9 <<
501 l.andi r4,r4,0x7c <<
502 l.add r4,r4,r1 <<
503 l.lwz r5,0(r4) <<
504 l.sb 1(r2),r5 <<
505 l.srli r5,r5,8 <<
506 l.j align_end <<
507 l.sb 0(r2),r5 <<
508 <<
509 sw: <<
510 l.srli r4,r3,9 <<
511 l.andi r4,r4,0x7c <<
512 l.add r4,r4,r1 <<
513 l.lwz r5,0(r4) <<
514 l.sb 3(r2),r5 <<
515 l.srli r5,r5,8 <<
516 l.sb 2(r2),r5 <<
517 l.srli r5,r5,8 <<
518 l.sb 1(r2),r5 <<
519 l.srli r5,r5,8 <<
520 l.j align_end <<
521 l.sb 0(r2),r5 <<
522 <<
523 align_end: <<
524 l.j _ret_from_intr <<
525 l.nop <<
526 #endif <<
527 <<
528 /* ---[ 0x700: Illegal insn exception ]------- <<
529 <<
530 EXCEPTION_ENTRY(_illegal_instruction_handler) <<
531 /* r4: EA of fault (set by EXCEPTION_H <<
532 l.jal do_illegal_instruction <<
533 l.addi r3,r1,0 /* pt_regs */ <<
534 <<
535 l.j _ret_from_exception <<
536 l.nop <<
537 <<
538 /* ---[ 0x800: External interrupt exception ]- <<
539 <<
540 EXCEPTION_ENTRY(_external_irq_handler) <<
541 #ifdef CONFIG_OPENRISC_ESR_EXCEPTION_BUG_CHECK <<
542 l.lwz r4,PT_SR(r1) // wer <<
543 l.andi r4,r4,SPR_SR_IEE <<
544 l.sfeqi r4,0 <<
545 l.bnf 1f // ext <<
546 l.nop <<
547 <<
548 #ifdef CONFIG_PRINTK <<
549 l.addi r1,r1,-0x8 <<
550 l.movhi r3,hi(42f) <<
551 l.ori r3,r3,lo(42f) <<
552 l.sw 0x0(r1),r3 <<
553 l.jal _printk <<
554 l.sw 0x4(r1),r4 <<
555 l.addi r1,r1,0x8 <<
556 <<
557 .section .rodata, "a" <<
558 42: <<
559 .string "\n\rESR interrupt bug <<
560 .align 4 <<
561 .previous <<
562 #endif <<
563 <<
564 l.ori r4,r4,SPR_SR_IEE // fix <<
565 // l.sw PT_SR(r1),r4 <<
566 1: <<
567 #endif <<
568 CLEAR_LWA_FLAG(r3) <<
569 l.addi r3,r1,0 <<
570 l.movhi r8,hi(generic_handle_arch_irq) <<
571 l.ori r8,r8,lo(generic_handle_arch_i <<
572 l.jalr r8 <<
573 l.nop <<
574 l.j _ret_from_intr <<
575 l.nop <<
576 <<
577 /* ---[ 0x900: DTLB miss exception ]---------- <<
578 <<
579 <<
580 /* ---[ 0xa00: ITLB miss exception ]---------- <<
581 <<
582 <<
583 /* ---[ 0xb00: Range exception ]-------------- <<
584 <<
585 UNHANDLED_EXCEPTION(_vector_0xb00,0xb00) <<
586 <<
587 /* ---[ 0xc00: Syscall exception ]------------ <<
588 <<
589 /* <<
590 * Syscalls are a special type of exception in <<
591 * _explicitly_ invoked by userspace and can t <<
592 * held to conform to the same ABI as normal f <<
593 * respect to whether registers are preserved <<
594 * or not. <<
595 */ <<
596 <<
597 /* Upon syscall entry we just save the callee- <<
598 * and not the call-clobbered ones. <<
599 */ <<
600 <<
601 _string_syscall_return: <<
602 .string "syscall r9:0x%08x -> syscall( <<
603 .align 4 <<
604 <<
605 ENTRY(_sys_call_handler) <<
606 /* r1, EPCR, ESR a already saved */ <<
607 l.sw PT_GPR2(r1),r2 <<
608 /* r3-r8 must be saved because syscall <<
609 * on us being able to restart the sys <<
610 * they should be clobbered, otherwise <<
611 */ <<
612 l.sw PT_GPR3(r1),r3 <<
613 /* <<
614 * r4 already saved <<
615 * r4 holds the EEAR address of the fa <<
616 * then load the original r4 <<
617 */ <<
618 CLEAR_LWA_FLAG(r4) <<
619 l.lwz r4,PT_GPR4(r1) <<
620 l.sw PT_GPR5(r1),r5 <<
621 l.sw PT_GPR6(r1),r6 <<
622 l.sw PT_GPR7(r1),r7 <<
623 l.sw PT_GPR8(r1),r8 <<
624 l.sw PT_GPR9(r1),r9 <<
625 /* r10 already saved */ <<
626 l.sw PT_GPR11(r1),r11 <<
627 /* orig_gpr11 must be set for syscalls <<
628 l.sw PT_ORIG_GPR11(r1),r11 <<
629 /* r12,r13 already saved */ <<
630 <<
631 /* r14-r28 (even) aren't touched by th <<
632 * so we don't need to save them. How <<
633 * to userspace via a call to switch() <<
634 * switch() effectively clobbers them. <<
635 * such functions is handled in their <<
636 * and clone, below). <<
637 <<
638 /* r30 is the only register we clobber <<
639 /* r30 already saved */ <<
640 /* l.sw PT_GPR30(r1),r30 */ <<
641 <<
642 _syscall_check_trace_enter: <<
643 /* syscalls run with interrupts enable <<
644 TRACE_IRQS_ON_SYSCALL <<
645 ENABLE_INTERRUPTS(r29) // ena <<
646 <<
647 /* If TIF_SYSCALL_TRACE is set, then w <<
648 l.lwz r30,TI_FLAGS(r10) <<
649 l.andi r30,r30,_TIF_SYSCALL_TRACE <<
650 l.sfne r30,r0 <<
651 l.bf _syscall_trace_enter <<
652 l.nop <<
653 <<
654 _syscall_check: <<
655 /* Ensure that the syscall number is r <<
656 l.sfgeui r11,__NR_syscalls <<
657 l.bf _syscall_badsys <<
658 l.nop <<
659 <<
660 _syscall_call: <<
661 l.movhi r29,hi(sys_call_table) <<
662 l.ori r29,r29,lo(sys_call_table) <<
663 l.slli r11,r11,2 <<
664 l.add r29,r29,r11 <<
665 l.lwz r29,0(r29) <<
666 <<
667 l.jalr r29 <<
668 l.nop <<
669 <<
670 _syscall_return: <<
671 /* All syscalls return here... just pa <<
672 * which does it in a round-about way. <<
673 */ <<
674 l.sw PT_GPR11(r1),r11 // <<
675 <<
676 #if 0 <<
677 _syscall_debug: <<
678 l.movhi r3,hi(_string_syscall_return) <<
679 l.ori r3,r3,lo(_string_syscall_retur <<
680 l.ori r27,r0,2 <<
681 l.sw -4(r1),r27 <<
682 l.sw -8(r1),r11 <<
683 l.lwz r29,PT_ORIG_GPR11(r1) <<
684 l.sw -12(r1),r29 <<
685 l.lwz r29,PT_GPR9(r1) <<
686 l.sw -16(r1),r29 <<
687 l.movhi r27,hi(_printk) <<
688 l.ori r27,r27,lo(_printk) <<
689 l.jalr r27 <<
690 l.addi r1,r1,-16 <<
691 l.addi r1,r1,16 <<
692 #endif <<
693 #if 0 <<
694 _syscall_show_regs: <<
695 l.movhi r27,hi(show_registers) <<
696 l.ori r27,r27,lo(show_registers) <<
697 l.jalr r27 <<
698 l.or r3,r1,r1 <<
699 #endif <<
700 <<
701 _syscall_check_trace_leave: <<
702 /* r30 is a callee-saved register so t <<
703 * _TIF_SYSCALL_TRACE flag from _sysca <<
704 * _syscall_trace_leave expects syscal <<
705 */ <<
706 l.sfne r30,r0 <<
707 l.bf _syscall_trace_leave <<
708 l.nop <<
709 <<
710 /* This is where the exception-return code beg <<
711 * disabled the rest of the way here because w <<
712 * interrupts that set NEED_RESCHED or SIGNALP <<
713 <<
714 _syscall_check_work: <<
715 /* Here we need to disable interrupts <<
716 DISABLE_INTERRUPTS(r27,r29) <<
717 TRACE_IRQS_OFF <<
718 l.lwz r30,TI_FLAGS(r10) <<
719 l.andi r30,r30,_TIF_WORK_MASK <<
720 l.sfne r30,r0 <<
721 <<
722 l.bnf _syscall_resume_userspace <<
723 l.nop <<
724 <<
725 /* Work pending follows a different re <<
726 * make sure that all the call-saved r <<
727 * before branching... <<
728 */ <<
729 l.sw PT_GPR14(r1),r14 <<
730 l.sw PT_GPR16(r1),r16 <<
731 l.sw PT_GPR18(r1),r18 <<
732 l.sw PT_GPR20(r1),r20 <<
733 l.sw PT_GPR22(r1),r22 <<
734 l.sw PT_GPR24(r1),r24 <<
735 l.sw PT_GPR26(r1),r26 <<
736 l.sw PT_GPR28(r1),r28 <<
737 <<
738 /* _work_pending needs to be called wi <<
739 l.j _work_pending <<
740 l.nop <<
741 <<
742 _syscall_resume_userspace: <<
743 // ENABLE_INTERRUPTS(r29) <<
744 <<
745 <<
746 /* This is the hot path for returning to users <<
747 * work to be done and the branch to _work_pen <<
748 * return to userspace will be done via the no <<
749 * that path restores _all_ registers and will <<
750 * registers with whatever garbage is in pt_re <<
751 * registers are clobbered anyway and because <<
752 * in the context of the extra work that _work <<
753 <<
754 /* Once again, syscalls are special and only g <<
755 * same registers as a normal function call */ <<
756 <<
757 /* The assumption here is that the registers r <<
758 * don't need to be restored... be sure that t <<
759 */ <<
760 <<
761 /* This is still too much... we should only be <<
762 * clobbered... we should even be using 'scrat <<
763 * we don't need to restore anything, hardly.. <<
764 */ <<
765 <<
766 l.lwz r2,PT_GPR2(r1) <<
767 <<
768 /* Restore args */ <<
769 /* r3-r8 are technically clobbered, bu <<
770 * to be restored... <<
771 */ <<
772 l.lwz r3,PT_GPR3(r1) <<
773 l.lwz r4,PT_GPR4(r1) <<
774 l.lwz r5,PT_GPR5(r1) <<
775 l.lwz r6,PT_GPR6(r1) <<
776 l.lwz r7,PT_GPR7(r1) <<
777 l.lwz r8,PT_GPR8(r1) <<
778 <<
779 l.lwz r9,PT_GPR9(r1) <<
780 l.lwz r10,PT_GPR10(r1) <<
781 l.lwz r11,PT_GPR11(r1) <<
782 <<
783 /* r30 is the only register we clobber <<
784 l.lwz r30,PT_GPR30(r1) <<
785 <<
786 /* Here we use r13-r19 (odd) as scratc <<
787 l.lwz r13,PT_PC(r1) <<
788 l.lwz r15,PT_SR(r1) <<
789 l.lwz r1,PT_SP(r1) <<
790 /* Interrupts need to be disabled for <<
791 * so that another interrupt doesn't c <<
792 * them before we can use them for our <<
793 DISABLE_INTERRUPTS(r17,r19) <<
794 l.mtspr r0,r13,SPR_EPCR_BASE <<
795 l.mtspr r0,r15,SPR_ESR_BASE <<
796 l.rfe <<
797 <<
798 /* End of hot path! <<
799 * Keep the below tracing and error handling o <<
800 */ <<
801 <<
802 _syscall_trace_enter: <<
803 /* Here we pass pt_regs to do_syscall_ <<
804 * that function is really getting all <<
805 * pt_regs isn't a complete set of use <<
806 * ones relevant to the syscall... <<
807 * <<
808 * Note use of delay slot for setting <<
809 */ <<
810 l.jal do_syscall_trace_enter <<
811 l.addi r3,r1,0 <<
812 <<
813 /* Restore arguments (not preserved ac <<
814 * so that we can do the syscall for r <<
815 * hot path. <<
816 */ <<
817 l.lwz r11,PT_GPR11(r1) <<
818 l.lwz r3,PT_GPR3(r1) <<
819 l.lwz r4,PT_GPR4(r1) <<
820 l.lwz r5,PT_GPR5(r1) <<
821 l.lwz r6,PT_GPR6(r1) <<
822 l.lwz r7,PT_GPR7(r1) <<
823 <<
824 l.j _syscall_check <<
825 l.lwz r8,PT_GPR8(r1) <<
826 <<
827 _syscall_trace_leave: <<
828 l.jal do_syscall_trace_leave <<
829 l.addi r3,r1,0 <<
830 <<
831 l.j _syscall_check_work <<
832 l.nop <<
833 <<
834 _syscall_badsys: <<
835 /* Here we effectively pretend to have <<
836 * syscall that returns -ENOSYS and th <<
837 * syscall hot path. <<
838 * Note that "return value" is set in <<
839 */ <<
840 l.j _syscall_return <<
841 l.addi r11,r0,-ENOSYS <<
842 <<
843 /******* END SYSCALL HANDLING *******/ <<
844 <<
845 /* ---[ 0xd00: Floating Point exception ]----- <<
846 <<
847 EXCEPTION_ENTRY(_fpe_trap_handler) <<
848 CLEAR_LWA_FLAG(r3) <<
849 <<
850 /* r4: EA of fault (set by EXCEPTION_H <<
851 l.jal do_fpe_trap <<
852 l.addi r3,r1,0 /* pt_regs */ <<
853 <<
854 l.j _ret_from_exception <<
855 l.nop <<
856 <<
857 /* ---[ 0xe00: Trap exception ]--------------- <<
858 <<
859 EXCEPTION_ENTRY(_trap_handler) <<
860 CLEAR_LWA_FLAG(r3) <<
861 /* r4: EA of fault (set by EXCEPTION_H <<
862 l.jal do_trap <<
863 l.addi r3,r1,0 /* pt_regs */ <<
864 <<
865 l.j _ret_from_exception <<
866 l.nop <<
867 <<
868 /* ---[ 0xf00: Reserved exception ]----------- <<
869 <<
870 UNHANDLED_EXCEPTION(_vector_0xf00,0xf00) <<
871 <<
872 /* ---[ 0x1000: Reserved exception ]---------- <<
873 <<
874 UNHANDLED_EXCEPTION(_vector_0x1000,0x1000) <<
875 <<
876 /* ---[ 0x1100: Reserved exception ]---------- <<
877 <<
878 UNHANDLED_EXCEPTION(_vector_0x1100,0x1100) <<
879 <<
880 /* ---[ 0x1200: Reserved exception ]---------- <<
881 <<
882 UNHANDLED_EXCEPTION(_vector_0x1200,0x1200) <<
883 <<
884 /* ---[ 0x1300: Reserved exception ]---------- <<
885 <<
886 UNHANDLED_EXCEPTION(_vector_0x1300,0x1300) <<
887 <<
888 /* ---[ 0x1400: Reserved exception ]---------- <<
889 <<
890 UNHANDLED_EXCEPTION(_vector_0x1400,0x1400) <<
891 <<
892 /* ---[ 0x1500: Reserved exception ]---------- <<
893 <<
894 UNHANDLED_EXCEPTION(_vector_0x1500,0x1500) <<
895 <<
896 /* ---[ 0x1600: Reserved exception ]---------- <<
897 <<
898 UNHANDLED_EXCEPTION(_vector_0x1600,0x1600) <<
899 <<
900 /* ---[ 0x1700: Reserved exception ]---------- <<
901 <<
902 UNHANDLED_EXCEPTION(_vector_0x1700,0x1700) <<
903 <<
904 /* ---[ 0x1800: Reserved exception ]---------- <<
905 <<
906 UNHANDLED_EXCEPTION(_vector_0x1800,0x1800) <<
907 <<
908 /* ---[ 0x1900: Reserved exception ]---------- <<
909 <<
910 UNHANDLED_EXCEPTION(_vector_0x1900,0x1900) <<
911 <<
912 /* ---[ 0x1a00: Reserved exception ]---------- <<
913 <<
914 UNHANDLED_EXCEPTION(_vector_0x1a00,0x1a00) <<
915 <<
916 /* ---[ 0x1b00: Reserved exception ]---------- <<
917 <<
918 UNHANDLED_EXCEPTION(_vector_0x1b00,0x1b00) <<
919 <<
920 /* ---[ 0x1c00: Reserved exception ]---------- <<
921 <<
922 UNHANDLED_EXCEPTION(_vector_0x1c00,0x1c00) <<
923 <<
924 /* ---[ 0x1d00: Reserved exception ]---------- <<
925 <<
926 UNHANDLED_EXCEPTION(_vector_0x1d00,0x1d00) <<
927 <<
928 /* ---[ 0x1e00: Reserved exception ]---------- <<
929 <<
930 UNHANDLED_EXCEPTION(_vector_0x1e00,0x1e00) <<
931 <<
932 /* ---[ 0x1f00: Reserved exception ]---------- <<
933 <<
934 UNHANDLED_EXCEPTION(_vector_0x1f00,0x1f00) <<
935 <<
936 /* =========================================== <<
937 <<
938 _resume_userspace: <<
939 DISABLE_INTERRUPTS(r3,r4) <<
940 TRACE_IRQS_OFF 127 TRACE_IRQS_OFF
941 l.lwz r4,TI_FLAGS(r10) !! 128 jal schedule
942 l.andi r13,r4,_TIF_WORK_MASK <<
943 l.sfeqi r13,0 <<
944 l.bf _restore_all <<
945 l.nop <<
946 <<
947 _work_pending: <<
948 l.lwz r5,PT_ORIG_GPR11(r1) <<
949 l.sfltsi r5,0 <<
950 l.bnf 1f <<
951 l.nop <<
952 l.andi r5,r5,0 <<
953 1: <<
954 l.jal do_work_pending <<
955 l.ori r3,r1,0 /* pt_ <<
956 129
957 l.sfeqi r11,0 !! 130 local_irq_disable # make sure need_resched and
958 l.bf _restore_all !! 131 # signals dont change between
959 l.nop !! 132 # sampling and return
960 l.sfltsi r11,0 !! 133 LONG_L a2, TI_FLAGS($28)
961 l.bnf 1f !! 134 andi t0, a2, _TIF_WORK_MASK # is there any work to be done
962 l.nop !! 135 # other than syscall tracing?
963 l.and r11,r11,r0 !! 136 beqz t0, restore_all
964 l.ori r11,r11,__NR_restart_syscall !! 137 andi t0, a2, _TIF_NEED_RESCHED
965 l.j _syscall_check_trace_enter !! 138 bnez t0, work_resched
966 l.nop !! 139
967 1: !! 140 work_notifysig: # deal with pending signals and
968 l.lwz r11,PT_ORIG_GPR11(r1) !! 141 # notify-resume requests
969 /* Restore arg registers */ !! 142 move a0, sp
970 l.lwz r3,PT_GPR3(r1) !! 143 li a1, 0
971 l.lwz r4,PT_GPR4(r1) !! 144 jal do_notify_resume # a2 already loaded
972 l.lwz r5,PT_GPR5(r1) !! 145 j resume_userspace_check
973 l.lwz r6,PT_GPR6(r1) !! 146
974 l.lwz r7,PT_GPR7(r1) !! 147 FEXPORT(syscall_exit_partial)
975 l.j _syscall_check_trace_enter !! 148 #ifdef CONFIG_DEBUG_RSEQ
976 l.lwz r8,PT_GPR8(r1) !! 149 move a0, sp
977 !! 150 jal rseq_syscall
978 _restore_all: !! 151 #endif
979 #ifdef CONFIG_TRACE_IRQFLAGS !! 152 local_irq_disable # make sure need_resched doesn't
980 l.lwz r4,PT_SR(r1) !! 153 # change between and return
981 l.andi r3,r4,(SPR_SR_IEE|SPR_SR_TEE) !! 154 LONG_L a2, TI_FLAGS($28) # current->work
982 l.sfeq r3,r0 /* skip trace !! 155 li t0, _TIF_ALLWORK_MASK
983 l.bf skip_hardirqs_on !! 156 and t0, a2
984 l.nop !! 157 beqz t0, restore_partial
>> 158 SAVE_STATIC
>> 159 syscall_exit_work:
>> 160 LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
>> 161 andi t0, t0, KU_USER
>> 162 beqz t0, resume_kernel
>> 163 li t0, _TIF_WORK_SYSCALL_EXIT
>> 164 and t0, a2 # a2 is preloaded with TI_FLAGS
>> 165 beqz t0, work_pending # trace bit set?
>> 166 local_irq_enable # could let syscall_trace_leave()
>> 167 # call schedule() instead
985 TRACE_IRQS_ON 168 TRACE_IRQS_ON
986 skip_hardirqs_on: !! 169 move a0, sp
987 #endif !! 170 jal syscall_trace_leave
988 RESTORE_ALL !! 171 b resume_userspace
989 /* This returns to userspace code */ <<
990 <<
991 <<
992 ENTRY(_ret_from_intr) <<
993 ENTRY(_ret_from_exception) <<
994 l.lwz r4,PT_SR(r1) <<
995 l.andi r3,r4,SPR_SR_SM <<
996 l.sfeqi r3,0 <<
997 l.bnf _restore_all <<
998 l.nop <<
999 l.j _resume_userspace <<
1000 l.nop <<
1001 172
1002 ENTRY(ret_from_fork) !! 173 #if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6) || \
1003 l.jal schedule_tail !! 174 defined(CONFIG_MIPS_MT)
1004 l.nop <<
1005 <<
1006 /* Check if we are a kernel thread */ <<
1007 l.sfeqi r20,0 <<
1008 l.bf 1f <<
1009 l.nop <<
1010 <<
1011 /* ...we are a kernel thread so invok <<
1012 l.jalr r20 <<
1013 l.or r3,r22,r0 <<
1014 <<
1015 1: <<
1016 /* _syscall_returns expect r11 to con <<
1017 l.lwz r11,PT_GPR11(r1) <<
1018 <<
1019 /* The syscall fast path return expec <<
1020 * r14-r28 to be untouched, so we res <<
1021 * will have been effectively clobber <<
1022 * via the call to switch() <<
1023 */ <<
1024 l.lwz r14,PT_GPR14(r1) <<
1025 l.lwz r16,PT_GPR16(r1) <<
1026 l.lwz r18,PT_GPR18(r1) <<
1027 l.lwz r20,PT_GPR20(r1) <<
1028 l.lwz r22,PT_GPR22(r1) <<
1029 l.lwz r24,PT_GPR24(r1) <<
1030 l.lwz r26,PT_GPR26(r1) <<
1031 l.lwz r28,PT_GPR28(r1) <<
1032 <<
1033 l.j _syscall_return <<
1034 l.nop <<
1035 <<
1036 /* ========================================== <<
1037 175
1038 /* 176 /*
1039 * This routine switches between two differen !! 177 * MIPS32R2 Instruction Hazard Barrier - must be called
1040 * state of one is saved on its kernel stack. <<
1041 * of the other is restored from its kernel s <<
1042 * management hardware is updated to the seco <<
1043 * Finally, we can return to the second proce <<
1044 * <<
1045 * Note: there are two ways to get to the "go <<
1046 * of this code; either by coming in via the <<
1047 * or via "fork" which must set up an environ <<
1048 * to the "_switch" path. If you change this <<
1049 * SAVE_REGS macro), you'll have to change th <<
1050 */ <<
1051 <<
1052 <<
1053 /* _switch MUST never lay on page boundry, ca <<
1054 * effective addresses and beeing interrupted <<
1055 * dTLB miss seems to never accour in the bad <<
1056 * are from task structures which are always <<
1057 * <<
1058 * The problem happens in RESTORE_ALL where w <<
1059 * register, then load the previous register <<
1060 * the l.rfe instruction. If get TLB miss in <<
1061 * garbled and we end up calling l.rfe with t <<
1062 * holds for ESR) <<
1063 * 178 *
1064 * To avoid this problems it is sufficient to !! 179 * For C code use the inline version named instruction_hazard().
1065 * some nice round number smaller than it's s <<
1066 */ 180 */
>> 181 LEAF(mips_ihb)
>> 182 .set MIPS_ISA_LEVEL_RAW
>> 183 jr.hb ra
>> 184 nop
>> 185 END(mips_ihb)
1067 186
1068 /* ABI rules apply here... we either enter _s !! 187 #endif /* CONFIG_CPU_MIPSR2 or CONFIG_CPU_MIPSR6 or CONFIG_MIPS_MT */
1069 * an imaginary call to which we shall return <<
1070 * way, we are a function call and only need <<
1071 * registers when we return. As such, we don <<
1072 * on the stack that we won't be returning as <<
1073 */ <<
1074 <<
1075 .align 0x400 <<
1076 ENTRY(_switch) <<
1077 /* We don't store SR as _switch only <<
1078 * the SR will be the same going in a <<
1079 <<
1080 /* Set up new pt_regs struct for savi <<
1081 l.addi r1,r1,-(INT_FRAME_SIZE) <<
1082 <<
1083 /* No need to store r1/PT_SP as it go <<
1084 l.sw PT_GPR2(r1),r2 <<
1085 l.sw PT_GPR9(r1),r9 <<
1086 <<
1087 /* Save callee-saved registers to the <<
1088 l.sw PT_GPR14(r1),r14 <<
1089 l.sw PT_GPR16(r1),r16 <<
1090 l.sw PT_GPR18(r1),r18 <<
1091 l.sw PT_GPR20(r1),r20 <<
1092 l.sw PT_GPR22(r1),r22 <<
1093 l.sw PT_GPR24(r1),r24 <<
1094 l.sw PT_GPR26(r1),r26 <<
1095 l.sw PT_GPR28(r1),r28 <<
1096 l.sw PT_GPR30(r1),r30 <<
1097 <<
1098 l.addi r11,r10,0 <<
1099 <<
1100 /* We use thread_info->ksp for storin <<
1101 * structure so that we can get back <<
1102 * to lose the value of thread_info-> <<
1103 * pt_regs->sp so that we can easily <<
1104 * live again... <<
1105 */ <<
1106 <<
1107 /* Save the old value of thread_info- <<
1108 l.lwz r29,TI_KSP(r10) <<
1109 l.sw PT_SP(r1),r29 <<
1110 <<
1111 /* Swap kernel stack pointers */ <<
1112 l.sw TI_KSP(r10),r1 <<
1113 l.or r10,r4,r0 <<
1114 l.lwz r1,TI_KSP(r10) <<
1115 <<
1116 /* Restore the old value of thread_in <<
1117 l.lwz r29,PT_SP(r1) <<
1118 l.sw TI_KSP(r10),r29 <<
1119 <<
1120 /* ...and restore the registers, exce <<
1121 * has already been set above. <<
1122 */ <<
1123 l.lwz r2,PT_GPR2(r1) <<
1124 l.lwz r9,PT_GPR9(r1) <<
1125 /* No need to restore r10 */ <<
1126 /* ...and do not restore r11 */ <<
1127 <<
1128 /* Restore callee-saved registers */ <<
1129 l.lwz r14,PT_GPR14(r1) <<
1130 l.lwz r16,PT_GPR16(r1) <<
1131 l.lwz r18,PT_GPR18(r1) <<
1132 l.lwz r20,PT_GPR20(r1) <<
1133 l.lwz r22,PT_GPR22(r1) <<
1134 l.lwz r24,PT_GPR24(r1) <<
1135 l.lwz r26,PT_GPR26(r1) <<
1136 l.lwz r28,PT_GPR28(r1) <<
1137 l.lwz r30,PT_GPR30(r1) <<
1138 <<
1139 /* Unwind stack to pre-switch state * <<
1140 l.addi r1,r1,(INT_FRAME_SIZE) <<
1141 <<
1142 /* Return via the link-register back <<
1143 * that may be either schedule(), ret <<
1144 * ret_from_kernel_thread(). If we a <<
1145 * we are expected to have set up the <<
1146 * hence we do so here unconditionall <<
1147 */ <<
1148 l.lwz r3,TI_TASK(r3) /* Lo <<
1149 l.jr r9 <<
1150 l.nop <<
1151 <<
1152 /* ========================================== <<
1153 <<
1154 /* These all use the delay slot for setting t <<
1155 * jump is always happening after the l.addi <<
1156 * <<
1157 * These are all just wrappers that don't tou <<
1158 * return from the "real" syscall function wi <<
1159 * code that did the l.jal that brought us he <<
1160 */ <<
1161 <<
1162 /* fork requires that we save all the callee- <<
1163 * are all effectively clobbered by the call <<
1164 * all the registers that aren't touched by t <<
1165 * weren't saved there. <<
1166 */ <<
1167 <<
1168 _fork_save_extra_regs_and_call: <<
1169 l.sw PT_GPR14(r1),r14 <<
1170 l.sw PT_GPR16(r1),r16 <<
1171 l.sw PT_GPR18(r1),r18 <<
1172 l.sw PT_GPR20(r1),r20 <<
1173 l.sw PT_GPR22(r1),r22 <<
1174 l.sw PT_GPR24(r1),r24 <<
1175 l.sw PT_GPR26(r1),r26 <<
1176 l.jr r29 <<
1177 l.sw PT_GPR28(r1),r28 <<
1178 <<
1179 ENTRY(__sys_clone) <<
1180 l.movhi r29,hi(sys_clone) <<
1181 l.j _fork_save_extra_regs_and_cal <<
1182 l.ori r29,r29,lo(sys_clone) <<
1183 <<
1184 ENTRY(__sys_clone3) <<
1185 l.movhi r29,hi(sys_clone3) <<
1186 l.j _fork_save_extra_regs_and_cal <<
1187 l.ori r29,r29,lo(sys_clone3) <<
1188 <<
1189 ENTRY(__sys_fork) <<
1190 l.movhi r29,hi(sys_fork) <<
1191 l.j _fork_save_extra_regs_and_cal <<
1192 l.ori r29,r29,lo(sys_fork) <<
1193 <<
1194 ENTRY(sys_rt_sigreturn) <<
1195 l.jal _sys_rt_sigreturn <<
1196 l.addi r3,r1,0 <<
1197 l.sfne r30,r0 <<
1198 l.bnf _no_syscall_trace <<
1199 l.nop <<
1200 l.jal do_syscall_trace_leave <<
1201 l.addi r3,r1,0 <<
1202 _no_syscall_trace: <<
1203 l.j _resume_userspace <<
1204 l.nop <<
1205 <<
1206 /* This is a catch-all syscall for atomic ins <<
1207 * The functions takes a variable number of p <<
1208 * particular flavour of atomic you want... p <<
1209 * the atomic in question. Currently, this f <<
1210 * following variants: <<
1211 * <<
1212 * XCHG: <<
1213 * @flag: 1 <<
1214 * @ptr1: <<
1215 * @ptr2: <<
1216 * Atomically exchange the values in pointers <<
1217 * <<
1218 */ <<
1219 <<
1220 ENTRY(sys_or1k_atomic) <<
1221 /* FIXME: This ignores r3 and always <<
1222 DISABLE_INTERRUPTS(r17,r19) <<
1223 l.lwz r29,0(r4) <<
1224 l.lwz r27,0(r5) <<
1225 l.sw 0(r4),r27 <<
1226 l.sw 0(r5),r29 <<
1227 ENABLE_INTERRUPTS(r17) <<
1228 l.jr r9 <<
1229 l.or r11,r0,r0 <<
1230 <<
1231 /* ========================================== <<
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