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Michal Simekca545022009-05-26 16:30:21 +02001/*
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
Michal Simek11d51362009-12-07 08:21:34 +010034#undef DEBUG
35
Michal Simekca545022009-05-26 16:30:21 +020036/* 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
Michal Simek66f7de862010-06-22 17:52:47 +020051 msrclr r0, MSR_BIP
Michal Simekca545022009-05-26 16:30:21 +020052 nop
53 .endm
54
55 .macro set_bip
Michal Simek66f7de862010-06-22 17:52:47 +020056 msrset r0, MSR_BIP
Michal Simekca545022009-05-26 16:30:21 +020057 nop
58 .endm
59
60 .macro clear_eip
Michal Simek66f7de862010-06-22 17:52:47 +020061 msrclr r0, MSR_EIP
Michal Simekca545022009-05-26 16:30:21 +020062 nop
63 .endm
64
65 .macro set_ee
Michal Simek66f7de862010-06-22 17:52:47 +020066 msrset r0, MSR_EE
Michal Simekca545022009-05-26 16:30:21 +020067 nop
68 .endm
69
70 .macro disable_irq
Michal Simek66f7de862010-06-22 17:52:47 +020071 msrclr r0, MSR_IE
Michal Simekca545022009-05-26 16:30:21 +020072 nop
73 .endm
74
75 .macro enable_irq
Michal Simek66f7de862010-06-22 17:52:47 +020076 msrset r0, MSR_IE
Michal Simekca545022009-05-26 16:30:21 +020077 nop
78 .endm
79
80 .macro set_ums
Michal Simek66f7de862010-06-22 17:52:47 +020081 msrset r0, MSR_UMS
Michal Simekca545022009-05-26 16:30:21 +020082 nop
Michal Simek66f7de862010-06-22 17:52:47 +020083 msrclr r0, MSR_VMS
Michal Simekca545022009-05-26 16:30:21 +020084 nop
85 .endm
86
87 .macro set_vms
Michal Simek66f7de862010-06-22 17:52:47 +020088 msrclr r0, MSR_UMS
Michal Simekca545022009-05-26 16:30:21 +020089 nop
Michal Simek66f7de862010-06-22 17:52:47 +020090 msrset r0, MSR_VMS
Michal Simekca545022009-05-26 16:30:21 +020091 nop
92 .endm
93
Michal Simekb3180672010-06-22 17:46:27 +020094 .macro clear_ums
Michal Simek66f7de862010-06-22 17:52:47 +020095 msrclr r0, MSR_UMS
Michal Simekb3180672010-06-22 17:46:27 +020096 nop
97 .endm
98
Michal Simekca545022009-05-26 16:30:21 +020099 .macro clear_vms_ums
Michal Simek66f7de862010-06-22 17:52:47 +0200100 msrclr r0, MSR_VMS | MSR_UMS
Michal Simekca545022009-05-26 16:30:21 +0200101 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
Michal Simekb3180672010-06-22 17:46:27 +0200170 .macro clear_ums
171 mfs r11, rmsr
172 nop
173 andni r11, r11, MSR_UMS
174 mts rmsr,r11
175 nop
176 .endm
177
Michal Simekca545022009-05-26 16:30:21 +0200178 .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 \
Michal Simeka4a94db2010-06-22 13:15:53 +0200194 set_ums; \
Michal Simekca545022009-05-26 16:30:21 +0200195 rted r0, 2f; \
Michal Simeka4a94db2010-06-22 13:15:53 +0200196 nop; \
1972:
Michal Simekca545022009-05-26 16:30:21 +0200198
199/* turn off virtual protected mode save and user mode save*/
200#define VM_OFF \
Michal Simeka4a94db2010-06-22 13:15:53 +0200201 clear_vms_ums; \
Michal Simekca545022009-05-26 16:30:21 +0200202 rted r0, TOPHYS(1f); \
Michal Simeka4a94db2010-06-22 13:15:53 +0200203 nop; \
2041:
Michal Simekca545022009-05-26 16:30:21 +0200205
206#define SAVE_REGS \
207 swi r2, r1, PTO+PT_R2; /* Save SDA */ \
Michal Simek36f60952010-06-22 13:27:43 +0200208 swi r3, r1, PTO+PT_R3; \
209 swi r4, r1, PTO+PT_R4; \
Michal Simekca545022009-05-26 16:30:21 +0200210 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 */ \
Michal Simek36f60952010-06-22 13:27:43 +0200244 lwi r3, r1, PTO+PT_R3; \
245 lwi r4, r1, PTO+PT_R4; \
Michal Simekca545022009-05-26 16:30:21 +0200246 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
Michal Simeke5d2af22010-06-22 17:58:26 +0200272#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)); \
282 tophys(r1,r1); \
283 addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */\
284 SAVE_REGS \
285 swi r1, r1, PTO+PT_MODE; \
286 brid 2f; \
287 nop; /* Fill delay slot */ \
2881: /* User-mode state save. */ \
289 lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */\
290 tophys(r1,r1); \
291 lwi r1, r1, TS_THREAD_INFO; /* get the thread info */ \
292 addik r1, r1, THREAD_SIZE; /* calculate kernel stack pointer */\
293 tophys(r1,r1); \
294 addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */\
295 SAVE_REGS \
296 swi r0, r1, PTO + PT_MODE; /* Was in user-mode. */ \
297 lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \
298 swi r11, r1, PTO+PT_R1; /* Store user SP. */ \
299 /* MS: I am clearing UMS even in case when I come from kernel space */ \
300 clear_ums; \
3012: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
302
Michal Simekca545022009-05-26 16:30:21 +0200303.text
304
305/*
306 * User trap.
307 *
308 * System calls are handled here.
309 *
310 * Syscall protocol:
311 * Syscall number in r12, args in r5-r10
312 * Return value in r3
313 *
314 * Trap entered via brki instruction, so BIP bit is set, and interrupts
315 * are masked. This is nice, means we don't have to CLI before state save
316 */
317C_ENTRY(_user_exception):
318 swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */
319 addi r14, r14, 4 /* return address is 4 byte after call */
Michal Simekca545022009-05-26 16:30:21 +0200320
Michal Simek653e4472010-06-22 14:51:45 +0200321 mfs r1, rmsr
Michal Simek5c0d72b2010-06-22 14:00:12 +0200322 nop
Michal Simek653e4472010-06-22 14:51:45 +0200323 andi r1, r1, MSR_UMS
324 bnei r1, 1f
Michal Simek5c0d72b2010-06-22 14:00:12 +0200325
326/* Kernel-mode state save - kernel execve */
Michal Simek653e4472010-06-22 14:51:45 +0200327 lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/
328 tophys(r1,r1);
Michal Simekca545022009-05-26 16:30:21 +0200329
330 addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
331 SAVE_REGS
332
Michal Simek77f6d222010-06-22 16:39:56 +0200333 swi r1, r1, PTO + PT_MODE; /* pt_regs -> kernel mode */
Michal Simekca545022009-05-26 16:30:21 +0200334 brid 2f;
335 nop; /* Fill delay slot */
336
337/* User-mode state save. */
3381:
Michal Simekca545022009-05-26 16:30:21 +0200339 lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
340 tophys(r1,r1);
341 lwi r1, r1, TS_THREAD_INFO; /* get stack from task_struct */
342/* calculate kernel stack pointer from task struct 8k */
343 addik r1, r1, THREAD_SIZE;
344 tophys(r1,r1);
345
346 addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
347 SAVE_REGS
348
Michal Simek77f6d222010-06-22 16:39:56 +0200349 swi r0, r1, PTO + PT_MODE; /* Was in user-mode. */
Michal Simekca545022009-05-26 16:30:21 +0200350 lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
351 swi r11, r1, PTO+PT_R1; /* Store user SP. */
Michal Simekb1d70c62010-01-22 10:24:06 +01003522: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
Michal Simekca545022009-05-26 16:30:21 +0200353 /* Save away the syscall number. */
354 swi r12, r1, PTO+PT_R0;
355 tovirt(r1,r1)
356
Michal Simekca545022009-05-26 16:30:21 +0200357/* where the trap should return need -8 to adjust for rtsd r15, 8*/
358/* Jump to the appropriate function for the system call number in r12
359 * (r12 is not preserved), or return an error if r12 is not valid. The LP
360 * register should point to the location where
361 * the called function should return. [note that MAKE_SYS_CALL uses label 1] */
Michal Simek23575482009-08-24 13:26:04 +0200362
363 # Step into virtual mode.
364 set_vms;
365 addik r11, r0, 3f
366 rtid r11, 0
367 nop
3683:
Michal Simekb1d70c62010-01-22 10:24:06 +0100369 lwi r11, CURRENT_TASK, TS_THREAD_INFO /* get thread info */
Michal Simek23575482009-08-24 13:26:04 +0200370 lwi r11, r11, TI_FLAGS /* get flags in thread info */
371 andi r11, r11, _TIF_WORK_SYSCALL_MASK
372 beqi r11, 4f
373
374 addik r3, r0, -ENOSYS
375 swi r3, r1, PTO + PT_R3
376 brlid r15, do_syscall_trace_enter
377 addik r5, r1, PTO + PT_R0
378
379 # do_syscall_trace_enter returns the new syscall nr.
380 addk r12, r0, r3
381 lwi r5, r1, PTO+PT_R5;
382 lwi r6, r1, PTO+PT_R6;
383 lwi r7, r1, PTO+PT_R7;
384 lwi r8, r1, PTO+PT_R8;
385 lwi r9, r1, PTO+PT_R9;
386 lwi r10, r1, PTO+PT_R10;
3874:
388/* Jump to the appropriate function for the system call number in r12
389 * (r12 is not preserved), or return an error if r12 is not valid.
390 * The LP register should point to the location where the called function
391 * should return. [note that MAKE_SYS_CALL uses label 1] */
392 /* See if the system call number is valid */
Michal Simekca545022009-05-26 16:30:21 +0200393 addi r11, r12, -__NR_syscalls;
Michal Simek23575482009-08-24 13:26:04 +0200394 bgei r11,5f;
Michal Simekca545022009-05-26 16:30:21 +0200395 /* Figure out which function to use for this system call. */
396 /* Note Microblaze barrel shift is optional, so don't rely on it */
397 add r12, r12, r12; /* convert num -> ptr */
398 add r12, r12, r12;
399
Michal Simek11d51362009-12-07 08:21:34 +0100400#ifdef DEBUG
Michal Simekca545022009-05-26 16:30:21 +0200401 /* Trac syscalls and stored them to r0_ram */
Michal Simek23575482009-08-24 13:26:04 +0200402 lwi r3, r12, 0x400 + r0_ram
Michal Simekca545022009-05-26 16:30:21 +0200403 addi r3, r3, 1
Michal Simek23575482009-08-24 13:26:04 +0200404 swi r3, r12, 0x400 + r0_ram
Michal Simek11d51362009-12-07 08:21:34 +0100405#endif
Michal Simekca545022009-05-26 16:30:21 +0200406
Michal Simek23575482009-08-24 13:26:04 +0200407 # Find and jump into the syscall handler.
408 lwi r12, r12, sys_call_table
409 /* where the trap should return need -8 to adjust for rtsd r15, 8 */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200410 addi r15, r0, ret_from_trap-8
Michal Simek23575482009-08-24 13:26:04 +0200411 bra r12
412
Michal Simekca545022009-05-26 16:30:21 +0200413 /* The syscall number is invalid, return an error. */
Michal Simek23575482009-08-24 13:26:04 +02004145:
Michal Simekca545022009-05-26 16:30:21 +0200415 addi r3, r0, -ENOSYS;
416 rtsd r15,8; /* looks like a normal subroutine return */
417 or r0, r0, r0
418
419
Michal Simek23575482009-08-24 13:26:04 +0200420/* Entry point used to return from a syscall/trap */
Michal Simekca545022009-05-26 16:30:21 +0200421/* We re-enable BIP bit before state restore */
422C_ENTRY(ret_from_trap):
Michal Simekb1d70c62010-01-22 10:24:06 +0100423 swi r3, r1, PTO + PT_R3
424 swi r4, r1, PTO + PT_R4
425
Michal Simek77f6d222010-06-22 16:39:56 +0200426 lwi r11, r1, PTO + PT_MODE;
Michal Simek36f60952010-06-22 13:27:43 +0200427/* See if returning to kernel mode, if so, skip resched &c. */
428 bnei r11, 2f;
Michal Simekca545022009-05-26 16:30:21 +0200429 /* We're returning to user mode, so check for various conditions that
430 * trigger rescheduling. */
Michal Simekb1d70c62010-01-22 10:24:06 +0100431 /* FIXME: Restructure all these flag checks. */
432 lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
Michal Simek23575482009-08-24 13:26:04 +0200433 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
434 andi r11, r11, _TIF_WORK_SYSCALL_MASK
435 beqi r11, 1f
436
Michal Simek23575482009-08-24 13:26:04 +0200437 brlid r15, do_syscall_trace_leave
438 addik r5, r1, PTO + PT_R0
Michal Simek23575482009-08-24 13:26:04 +02004391:
Michal Simek23575482009-08-24 13:26:04 +0200440 /* We're returning to user mode, so check for various conditions that
441 * trigger rescheduling. */
Michal Simekb1d70c62010-01-22 10:24:06 +0100442 /* get thread info from current task */
443 lwi r11, CURRENT_TASK, TS_THREAD_INFO;
Michal Simekca545022009-05-26 16:30:21 +0200444 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
445 andi r11, r11, _TIF_NEED_RESCHED;
446 beqi r11, 5f;
447
Michal Simekca545022009-05-26 16:30:21 +0200448 bralid r15, schedule; /* Call scheduler */
449 nop; /* delay slot */
Michal Simekca545022009-05-26 16:30:21 +0200450
451 /* Maybe handle a signal */
Michal Simekb1d70c62010-01-22 10:24:06 +01004525: /* get thread info from current task*/
453 lwi r11, CURRENT_TASK, TS_THREAD_INFO;
Michal Simekca545022009-05-26 16:30:21 +0200454 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
455 andi r11, r11, _TIF_SIGPENDING;
456 beqi r11, 1f; /* Signals to handle, handle them */
457
Michal Simekb9ea77e2010-07-28 12:40:02 +0200458 addik r5, r1, PTO; /* Arg 1: struct pt_regs *regs */
Michal Simekca545022009-05-26 16:30:21 +0200459 addi r7, r0, 1; /* Arg 3: int in_syscall */
460 bralid r15, do_signal; /* Handle any signals */
Michal Simek841d6e82010-01-22 14:28:36 +0100461 add r6, r0, r0; /* Arg 2: sigset_t *oldset */
Michal Simekb1d70c62010-01-22 10:24:06 +0100462
463/* Finally, return to user state. */
Michal Simek96014cc2010-06-22 14:05:43 +02004641: set_bip; /* Ints masked for state restore */
Michal Simek8633beb2010-02-22 13:24:43 +0100465 swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
Michal Simekca545022009-05-26 16:30:21 +0200466 VM_OFF;
467 tophys(r1,r1);
468 RESTORE_REGS;
469 addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
470 lwi r1, r1, PT_R1 - PT_SIZE;/* Restore user stack pointer. */
471 bri 6f;
472
473/* Return to kernel state. */
Michal Simek96014cc2010-06-22 14:05:43 +02004742: set_bip; /* Ints masked for state restore */
475 VM_OFF;
Michal Simekca545022009-05-26 16:30:21 +0200476 tophys(r1,r1);
477 RESTORE_REGS;
478 addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
479 tovirt(r1,r1);
4806:
481TRAP_return: /* Make global symbol for debugging */
482 rtbd r14, 0; /* Instructions to return from an IRQ */
483 nop;
484
485
486/* These syscalls need access to the struct pt_regs on the stack, so we
487 implement them in assembly (they're basically all wrappers anyway). */
488
489C_ENTRY(sys_fork_wrapper):
490 addi r5, r0, SIGCHLD /* Arg 0: flags */
491 lwi r6, r1, PTO+PT_R1 /* Arg 1: child SP (use parent's) */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200492 addik r7, r1, PTO /* Arg 2: parent context */
Michal Simekca545022009-05-26 16:30:21 +0200493 add r8. r0, r0 /* Arg 3: (unused) */
494 add r9, r0, r0; /* Arg 4: (unused) */
495 add r10, r0, r0; /* Arg 5: (unused) */
496 brid do_fork /* Do real work (tail-call) */
497 nop;
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). */
504C_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 ) */
508 add r3, r0, r0; /* Child's fork call should return 0. */
509 brid ret_from_trap; /* Do normal trap return */
510 nop;
511
Arnd Bergmanne5135882009-06-18 19:55:30 +0200512C_ENTRY(sys_vfork):
513 brid microblaze_vfork /* Do real work (tail-call) */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200514 addik r5, r1, PTO
Michal Simekca545022009-05-26 16:30:21 +0200515
Arnd Bergmanne5135882009-06-18 19:55:30 +0200516C_ENTRY(sys_clone):
Michal Simekca545022009-05-26 16:30:21 +0200517 bnei r6, 1f; /* See if child SP arg (arg 1) is 0. */
Michal Simek570e3e22010-06-04 13:06:27 +0200518 lwi r6, r1, PTO + PT_R1; /* If so, use paret's stack ptr */
Michal Simekb9ea77e2010-07-28 12:40:02 +02005191: addik r7, r1, PTO; /* Arg 2: parent context */
520 add r8, r0, r0; /* Arg 3: (unused) */
521 add r9, r0, r0; /* Arg 4: (unused) */
522 add r10, r0, r0; /* Arg 5: (unused) */
523 brid do_fork /* Do real work (tail-call) */
524 nop;
Michal Simekca545022009-05-26 16:30:21 +0200525
Arnd Bergmanne5135882009-06-18 19:55:30 +0200526C_ENTRY(sys_execve):
Michal Simekb9ea77e2010-07-28 12:40:02 +0200527 addik r8, r1, PTO; /* add user context as 4th arg */
Arnd Bergmanne5135882009-06-18 19:55:30 +0200528 brid microblaze_execve; /* Do real work (tail-call).*/
Michal Simekca545022009-05-26 16:30:21 +0200529 nop;
530
Michal Simekca545022009-05-26 16:30:21 +0200531C_ENTRY(sys_rt_sigreturn_wrapper):
532 swi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
533 swi r4, r1, PTO+PT_R4;
Michal Simekb9ea77e2010-07-28 12:40:02 +0200534 addik r5, r1, PTO; /* add user context as 1st arg */
Michal Simekca545022009-05-26 16:30:21 +0200535 brlid r15, sys_rt_sigreturn /* Do real work */
536 nop;
537 lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
538 lwi r4, r1, PTO+PT_R4;
539 bri ret_from_trap /* fall through will not work here due to align */
540 nop;
541
542/*
543 * HW EXCEPTION rutine start
544 */
Michal Simekca545022009-05-26 16:30:21 +0200545C_ENTRY(full_exception_trap):
Michal Simekca545022009-05-26 16:30:21 +0200546 /* adjust exception address for privileged instruction
547 * for finding where is it */
548 addik r17, r17, -4
549 SAVE_STATE /* Save registers */
Michal Simek06a54602010-06-22 16:22:01 +0200550 /* PC, before IRQ/trap - this is one instruction above */
551 swi r17, r1, PTO+PT_PC;
552 tovirt(r1,r1)
Michal Simekca545022009-05-26 16:30:21 +0200553 /* FIXME this can be store directly in PT_ESR reg.
554 * I tested it but there is a fault */
555 /* where the trap should return need -8 to adjust for rtsd r15, 8 */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200556 addik r15, r0, ret_from_exc - 8
557 addik r5, r1, PTO /* parameter struct pt_regs * regs */
Michal Simekca545022009-05-26 16:30:21 +0200558 mfs r6, resr
559 nop
560 mfs r7, rfsr; /* save FSR */
561 nop
Michal Simek131e4e92009-09-28 08:50:53 +0200562 mts rfsr, r0; /* Clear sticky fsr */
563 nop
Michal Simekc318d482010-06-22 16:25:31 +0200564 rted r0, full_exception
565 nop
Michal Simekca545022009-05-26 16:30:21 +0200566
567/*
568 * Unaligned data trap.
569 *
570 * Unaligned data trap last on 4k page is handled here.
571 *
572 * Trap entered via exception, so EE bit is set, and interrupts
573 * are masked. This is nice, means we don't have to CLI before state save
574 *
575 * The assembler routine is in "arch/microblaze/kernel/hw_exception_handler.S"
576 */
577C_ENTRY(unaligned_data_trap):
Michal Simek8b110d12010-06-17 16:03:05 +0200578 /* MS: I have to save r11 value and then restore it because
579 * set_bit, clear_eip, set_ee use r11 as temp register if MSR
580 * instructions are not used. We don't need to do if MSR instructions
581 * are used and they use r0 instead of r11.
582 * I am using ENTRY_SP which should be primary used only for stack
583 * pointer saving. */
584 swi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
585 set_bip; /* equalize initial state for all possible entries */
586 clear_eip;
587 set_ee;
588 lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
Michal Simekca545022009-05-26 16:30:21 +0200589 SAVE_STATE /* Save registers.*/
Michal Simek06a54602010-06-22 16:22:01 +0200590 /* PC, before IRQ/trap - this is one instruction above */
591 swi r17, r1, PTO+PT_PC;
592 tovirt(r1,r1)
Michal Simekca545022009-05-26 16:30:21 +0200593 /* where the trap should return need -8 to adjust for rtsd r15, 8 */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200594 addik r15, r0, ret_from_exc-8
Michal Simekca545022009-05-26 16:30:21 +0200595 mfs r3, resr /* ESR */
596 nop
597 mfs r4, rear /* EAR */
598 nop
Michal Simekc318d482010-06-22 16:25:31 +0200599 rtbd r0, _unaligned_data_exception
Michal Simekb9ea77e2010-07-28 12:40:02 +0200600 addik r7, r1, PTO /* parameter struct pt_regs * regs */
Michal Simekca545022009-05-26 16:30:21 +0200601
602/*
603 * Page fault traps.
604 *
605 * If the real exception handler (from hw_exception_handler.S) didn't find
606 * the mapping for the process, then we're thrown here to handle such situation.
607 *
608 * Trap entered via exceptions, so EE bit is set, and interrupts
609 * are masked. This is nice, means we don't have to CLI before state save
610 *
611 * Build a standard exception frame for TLB Access errors. All TLB exceptions
612 * will bail out to this point if they can't resolve the lightweight TLB fault.
613 *
614 * The C function called is in "arch/microblaze/mm/fault.c", declared as:
615 * void do_page_fault(struct pt_regs *regs,
616 * unsigned long address,
617 * unsigned long error_code)
618 */
619/* data and intruction trap - which is choose is resolved int fault.c */
620C_ENTRY(page_fault_data_trap):
Michal Simekca545022009-05-26 16:30:21 +0200621 SAVE_STATE /* Save registers.*/
Michal Simek06a54602010-06-22 16:22:01 +0200622 /* PC, before IRQ/trap - this is one instruction above */
623 swi r17, r1, PTO+PT_PC;
624 tovirt(r1,r1)
Michal Simekca545022009-05-26 16:30:21 +0200625 /* where the trap should return need -8 to adjust for rtsd r15, 8 */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200626 addik r15, r0, ret_from_exc-8
627 addik r5, r1, PTO /* parameter struct pt_regs * regs */
Michal Simekca545022009-05-26 16:30:21 +0200628 mfs r6, rear /* parameter unsigned long address */
629 nop
630 mfs r7, resr /* parameter unsigned long error_code */
631 nop
Michal Simekc318d482010-06-22 16:25:31 +0200632 rted r0, do_page_fault
633 nop
Michal Simekca545022009-05-26 16:30:21 +0200634
635C_ENTRY(page_fault_instr_trap):
Michal Simekca545022009-05-26 16:30:21 +0200636 SAVE_STATE /* Save registers.*/
Michal Simek06a54602010-06-22 16:22:01 +0200637 /* PC, before IRQ/trap - this is one instruction above */
638 swi r17, r1, PTO+PT_PC;
639 tovirt(r1,r1)
Michal Simekca545022009-05-26 16:30:21 +0200640 /* where the trap should return need -8 to adjust for rtsd r15, 8 */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200641 addik r15, r0, ret_from_exc-8
642 addik r5, r1, PTO /* parameter struct pt_regs * regs */
Michal Simekca545022009-05-26 16:30:21 +0200643 mfs r6, rear /* parameter unsigned long address */
644 nop
Michal Simekc318d482010-06-22 16:25:31 +0200645 rted r0, do_page_fault
Michal Simekca545022009-05-26 16:30:21 +0200646 ori r7, r0, 0 /* parameter unsigned long error_code */
Michal Simekca545022009-05-26 16:30:21 +0200647
648/* Entry point used to return from an exception. */
649C_ENTRY(ret_from_exc):
Michal Simek77f6d222010-06-22 16:39:56 +0200650 lwi r11, r1, PTO + PT_MODE;
Michal Simekca545022009-05-26 16:30:21 +0200651 bnei r11, 2f; /* See if returning to kernel mode, */
652 /* ... if so, skip resched &c. */
653
654 /* We're returning to user mode, so check for various conditions that
655 trigger rescheduling. */
Michal Simekb1d70c62010-01-22 10:24:06 +0100656 lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
Michal Simekca545022009-05-26 16:30:21 +0200657 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
658 andi r11, r11, _TIF_NEED_RESCHED;
659 beqi r11, 5f;
660
661/* Call the scheduler before returning from a syscall/trap. */
662 bralid r15, schedule; /* Call scheduler */
663 nop; /* delay slot */
664
665 /* Maybe handle a signal */
Michal Simekb1d70c62010-01-22 10:24:06 +01006665: lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
Michal Simekca545022009-05-26 16:30:21 +0200667 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
668 andi r11, r11, _TIF_SIGPENDING;
669 beqi r11, 1f; /* Signals to handle, handle them */
670
671 /*
672 * Handle a signal return; Pending signals should be in r18.
673 *
674 * Not all registers are saved by the normal trap/interrupt entry
675 * points (for instance, call-saved registers (because the normal
676 * C-compiler calling sequence in the kernel makes sure they're
677 * preserved), and call-clobbered registers in the case of
678 * traps), but signal handlers may want to examine or change the
679 * complete register state. Here we save anything not saved by
680 * the normal entry sequence, so that it may be safely restored
Michal Simek36f60952010-06-22 13:27:43 +0200681 * (in a possibly modified form) after do_signal returns. */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200682 addik r5, r1, PTO; /* Arg 1: struct pt_regs *regs */
Michal Simekca545022009-05-26 16:30:21 +0200683 addi r7, r0, 0; /* Arg 3: int in_syscall */
684 bralid r15, do_signal; /* Handle any signals */
Michal Simek841d6e82010-01-22 14:28:36 +0100685 add r6, r0, r0; /* Arg 2: sigset_t *oldset */
Michal Simekca545022009-05-26 16:30:21 +0200686
687/* Finally, return to user state. */
Michal Simek96014cc2010-06-22 14:05:43 +02006881: set_bip; /* Ints masked for state restore */
Michal Simek8633beb2010-02-22 13:24:43 +0100689 swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
Michal Simekca545022009-05-26 16:30:21 +0200690 VM_OFF;
691 tophys(r1,r1);
692
Michal Simekca545022009-05-26 16:30:21 +0200693 RESTORE_REGS;
694 addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
695
696 lwi r1, r1, PT_R1 - PT_SIZE; /* Restore user stack pointer. */
697 bri 6f;
698/* Return to kernel state. */
Michal Simek96014cc2010-06-22 14:05:43 +02006992: set_bip; /* Ints masked for state restore */
700 VM_OFF;
Michal Simekca545022009-05-26 16:30:21 +0200701 tophys(r1,r1);
Michal Simekca545022009-05-26 16:30:21 +0200702 RESTORE_REGS;
703 addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
704
705 tovirt(r1,r1);
7066:
707EXC_return: /* Make global symbol for debugging */
708 rtbd r14, 0; /* Instructions to return from an IRQ */
709 nop;
710
711/*
712 * HW EXCEPTION rutine end
713 */
714
715/*
716 * Hardware maskable interrupts.
717 *
718 * The stack-pointer (r1) should have already been saved to the memory
719 * location PER_CPU(ENTRY_SP).
720 */
721C_ENTRY(_interrupt):
722/* MS: we are in physical address */
723/* Save registers, switch to proper stack, convert SP to virtual.*/
724 swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP))
Michal Simekca545022009-05-26 16:30:21 +0200725 /* MS: See if already in kernel mode. */
Michal Simek653e4472010-06-22 14:51:45 +0200726 mfs r1, rmsr
Michal Simek5c0d72b2010-06-22 14:00:12 +0200727 nop
Michal Simek653e4472010-06-22 14:51:45 +0200728 andi r1, r1, MSR_UMS
729 bnei r1, 1f
Michal Simekca545022009-05-26 16:30:21 +0200730
731/* Kernel-mode state save. */
Michal Simek653e4472010-06-22 14:51:45 +0200732 lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP))
733 tophys(r1,r1); /* MS: I have in r1 physical address where stack is */
Michal Simekca545022009-05-26 16:30:21 +0200734 /* save registers */
735/* MS: Make room on the stack -> activation record */
736 addik r1, r1, -STATE_SAVE_SIZE;
Michal Simekca545022009-05-26 16:30:21 +0200737 SAVE_REGS
Michal Simek77f6d222010-06-22 16:39:56 +0200738 swi r1, r1, PTO + PT_MODE; /* 0 - user mode, 1 - kernel mode */
Michal Simekca545022009-05-26 16:30:21 +0200739 brid 2f;
740 nop; /* MS: Fill delay slot */
741
7421:
743/* User-mode state save. */
Michal Simekca545022009-05-26 16:30:21 +0200744 /* MS: get the saved current */
745 lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
746 tophys(r1,r1);
747 lwi r1, r1, TS_THREAD_INFO;
748 addik r1, r1, THREAD_SIZE;
749 tophys(r1,r1);
750 /* save registers */
751 addik r1, r1, -STATE_SAVE_SIZE;
Michal Simekca545022009-05-26 16:30:21 +0200752 SAVE_REGS
753 /* calculate mode */
754 swi r0, r1, PTO + PT_MODE;
755 lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
756 swi r11, r1, PTO+PT_R1;
Michal Simekca545022009-05-26 16:30:21 +02007572:
Michal Simekb1d70c62010-01-22 10:24:06 +0100758 lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
Michal Simekca545022009-05-26 16:30:21 +0200759 tovirt(r1,r1)
Michal Simekb9ea77e2010-07-28 12:40:02 +0200760 addik r5, r1, PTO;
Michal Simekca545022009-05-26 16:30:21 +0200761 set_vms;
Michal Simekb9ea77e2010-07-28 12:40:02 +0200762 addik r11, r0, do_IRQ;
763 addik r15, r0, irq_call;
Michal Simekca545022009-05-26 16:30:21 +0200764irq_call:rtbd r11, 0;
765 nop;
766
767/* MS: we are in virtual mode */
768ret_from_irq:
769 lwi r11, r1, PTO + PT_MODE;
770 bnei r11, 2f;
771
Michal Simekb1d70c62010-01-22 10:24:06 +0100772 lwi r11, CURRENT_TASK, TS_THREAD_INFO;
Michal Simekca545022009-05-26 16:30:21 +0200773 lwi r11, r11, TI_FLAGS; /* MS: get flags from thread info */
774 andi r11, r11, _TIF_NEED_RESCHED;
775 beqi r11, 5f
776 bralid r15, schedule;
777 nop; /* delay slot */
778
779 /* Maybe handle a signal */
Michal Simekb1d70c62010-01-22 10:24:06 +01007805: lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* MS: get thread info */
Michal Simekca545022009-05-26 16:30:21 +0200781 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
782 andi r11, r11, _TIF_SIGPENDING;
783 beqid r11, no_intr_resched
784/* Handle a signal return; Pending signals should be in r18. */
785 addi r7, r0, 0; /* Arg 3: int in_syscall */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200786 addik r5, r1, PTO; /* Arg 1: struct pt_regs *regs */
Michal Simekca545022009-05-26 16:30:21 +0200787 bralid r15, do_signal; /* Handle any signals */
788 add r6, r0, r0; /* Arg 2: sigset_t *oldset */
789
790/* Finally, return to user state. */
791no_intr_resched:
792 /* Disable interrupts, we are now committed to the state restore */
793 disable_irq
Michal Simek8633beb2010-02-22 13:24:43 +0100794 swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE);
Michal Simekca545022009-05-26 16:30:21 +0200795 VM_OFF;
796 tophys(r1,r1);
Michal Simekca545022009-05-26 16:30:21 +0200797 RESTORE_REGS
798 addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */
799 lwi r1, r1, PT_R1 - PT_SIZE;
800 bri 6f;
801/* MS: Return to kernel state. */
Michal Simek77753792010-01-12 09:55:10 +01008022:
803#ifdef CONFIG_PREEMPT
Michal Simekb1d70c62010-01-22 10:24:06 +0100804 lwi r11, CURRENT_TASK, TS_THREAD_INFO;
Michal Simek77753792010-01-12 09:55:10 +0100805 /* MS: get preempt_count from thread info */
806 lwi r5, r11, TI_PREEMPT_COUNT;
807 bgti r5, restore;
808
809 lwi r5, r11, TI_FLAGS; /* get flags in thread info */
810 andi r5, r5, _TIF_NEED_RESCHED;
811 beqi r5, restore /* if zero jump over */
812
813preempt:
814 /* interrupts are off that's why I am calling preempt_chedule_irq */
815 bralid r15, preempt_schedule_irq
816 nop
Michal Simekb1d70c62010-01-22 10:24:06 +0100817 lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
Michal Simek77753792010-01-12 09:55:10 +0100818 lwi r5, r11, TI_FLAGS; /* get flags in thread info */
819 andi r5, r5, _TIF_NEED_RESCHED;
820 bnei r5, preempt /* if non zero jump to resched */
821restore:
822#endif
823 VM_OFF /* MS: turn off MMU */
Michal Simekca545022009-05-26 16:30:21 +0200824 tophys(r1,r1)
Michal Simekca545022009-05-26 16:30:21 +0200825 RESTORE_REGS
826 addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */
827 tovirt(r1,r1);
8286:
829IRQ_return: /* MS: Make global symbol for debugging */
830 rtid r14, 0
831 nop
832
833/*
834 * `Debug' trap
835 * We enter dbtrap in "BIP" (breakpoint) mode.
836 * So we exit the breakpoint mode with an 'rtbd' and proceed with the
837 * original dbtrap.
838 * however, wait to save state first
839 */
840C_ENTRY(_debug_exception):
841 /* BIP bit is set on entry, no interrupts can occur */
842 swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP))
843
Michal Simek653e4472010-06-22 14:51:45 +0200844 mfs r1, rmsr
Michal Simek5c0d72b2010-06-22 14:00:12 +0200845 nop
Michal Simek653e4472010-06-22 14:51:45 +0200846 andi r1, r1, MSR_UMS
847 bnei r1, 1f
Michal Simekca545022009-05-26 16:30:21 +0200848 /* Kernel-mode state save. */
Michal Simek653e4472010-06-22 14:51:45 +0200849 lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/
850 tophys(r1,r1);
Michal Simekca545022009-05-26 16:30:21 +0200851
852 addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
Michal Simekca545022009-05-26 16:30:21 +0200853 SAVE_REGS;
854
Michal Simek77f6d222010-06-22 16:39:56 +0200855 swi r1, r1, PTO + PT_MODE;
Michal Simekca545022009-05-26 16:30:21 +0200856 brid 2f;
857 nop; /* Fill delay slot */
8581: /* User-mode state save. */
Michal Simekca545022009-05-26 16:30:21 +0200859 lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
860 tophys(r1,r1);
861 lwi r1, r1, TS_THREAD_INFO; /* get the thread info */
862 addik r1, r1, THREAD_SIZE; /* calculate kernel stack pointer */
863 tophys(r1,r1);
864
865 addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
Michal Simekca545022009-05-26 16:30:21 +0200866 SAVE_REGS;
867
Michal Simek77f6d222010-06-22 16:39:56 +0200868 swi r0, r1, PTO + PT_MODE; /* Was in user-mode. */
Michal Simekca545022009-05-26 16:30:21 +0200869 lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
870 swi r11, r1, PTO+PT_R1; /* Store user SP. */
Michal Simek653e4472010-06-22 14:51:45 +02008712:
Michal Simekca545022009-05-26 16:30:21 +0200872 tovirt(r1,r1)
873
Michal Simek06b28642010-06-22 15:25:24 +0200874 set_vms;
Michal Simekca545022009-05-26 16:30:21 +0200875 addi r5, r0, SIGTRAP /* send the trap signal */
876 add r6, r0, CURRENT_TASK; /* Get current task ptr into r11 */
877 addk r7, r0, r0 /* 3rd param zero */
Michal Simek06b28642010-06-22 15:25:24 +0200878dbtrap_call: rtbd r0, send_sig;
Michal Simekb9ea77e2010-07-28 12:40:02 +0200879 addik r15, r0, dbtrap_call;
Michal Simekca545022009-05-26 16:30:21 +0200880
881 set_bip; /* Ints masked for state restore*/
Michal Simek77f6d222010-06-22 16:39:56 +0200882 lwi r11, r1, PTO + PT_MODE;
Michal Simekca545022009-05-26 16:30:21 +0200883 bnei r11, 2f;
884
885 /* Get current task ptr into r11 */
Michal Simekb1d70c62010-01-22 10:24:06 +0100886 lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
Michal Simekca545022009-05-26 16:30:21 +0200887 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
888 andi r11, r11, _TIF_NEED_RESCHED;
889 beqi r11, 5f;
890
891/* Call the scheduler before returning from a syscall/trap. */
892
893 bralid r15, schedule; /* Call scheduler */
894 nop; /* delay slot */
895 /* XXX Is PT_DTRACE handling needed here? */
896 /* XXX m68knommu also checks TASK_STATE & TASK_COUNTER here. */
897
898 /* Maybe handle a signal */
Michal Simekb1d70c62010-01-22 10:24:06 +01008995: lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
Michal Simekca545022009-05-26 16:30:21 +0200900 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
901 andi r11, r11, _TIF_SIGPENDING;
902 beqi r11, 1f; /* Signals to handle, handle them */
903
904/* Handle a signal return; Pending signals should be in r18. */
905 /* Not all registers are saved by the normal trap/interrupt entry
906 points (for instance, call-saved registers (because the normal
907 C-compiler calling sequence in the kernel makes sure they're
908 preserved), and call-clobbered registers in the case of
909 traps), but signal handlers may want to examine or change the
910 complete register state. Here we save anything not saved by
911 the normal entry sequence, so that it may be safely restored
912 (in a possibly modified form) after do_signal returns. */
913
Michal Simekb9ea77e2010-07-28 12:40:02 +0200914 addik r5, r1, PTO; /* Arg 1: struct pt_regs *regs */
Michal Simekca545022009-05-26 16:30:21 +0200915 addi r7, r0, 0; /* Arg 3: int in_syscall */
916 bralid r15, do_signal; /* Handle any signals */
Michal Simek841d6e82010-01-22 14:28:36 +0100917 add r6, r0, r0; /* Arg 2: sigset_t *oldset */
Michal Simekca545022009-05-26 16:30:21 +0200918
919
920/* Finally, return to user state. */
Michal Simek5c0d72b2010-06-22 14:00:12 +02009211:
Michal Simek8633beb2010-02-22 13:24:43 +0100922 swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
Michal Simekca545022009-05-26 16:30:21 +0200923 VM_OFF;
924 tophys(r1,r1);
925
Michal Simekca545022009-05-26 16:30:21 +0200926 RESTORE_REGS
927 addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
928
929
930 lwi r1, r1, PT_R1 - PT_SIZE;
931 /* Restore user stack pointer. */
932 bri 6f;
933
934/* Return to kernel state. */
9352: VM_OFF;
936 tophys(r1,r1);
Michal Simekca545022009-05-26 16:30:21 +0200937 RESTORE_REGS
938 addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
939
940 tovirt(r1,r1);
9416:
942DBTRAP_return: /* Make global symbol for debugging */
943 rtbd r14, 0; /* Instructions to return from an IRQ */
944 nop;
945
946
947
948ENTRY(_switch_to)
949 /* prepare return value */
Michal Simekb1d70c62010-01-22 10:24:06 +0100950 addk r3, r0, CURRENT_TASK
Michal Simekca545022009-05-26 16:30:21 +0200951
952 /* save registers in cpu_context */
953 /* use r11 and r12, volatile registers, as temp register */
954 /* give start of cpu_context for previous process */
955 addik r11, r5, TI_CPU_CONTEXT
956 swi r1, r11, CC_R1
957 swi r2, r11, CC_R2
958 /* skip volatile registers.
959 * they are saved on stack when we jumped to _switch_to() */
960 /* dedicated registers */
961 swi r13, r11, CC_R13
962 swi r14, r11, CC_R14
963 swi r15, r11, CC_R15
964 swi r16, r11, CC_R16
965 swi r17, r11, CC_R17
966 swi r18, r11, CC_R18
967 /* save non-volatile registers */
968 swi r19, r11, CC_R19
969 swi r20, r11, CC_R20
970 swi r21, r11, CC_R21
971 swi r22, r11, CC_R22
972 swi r23, r11, CC_R23
973 swi r24, r11, CC_R24
974 swi r25, r11, CC_R25
975 swi r26, r11, CC_R26
976 swi r27, r11, CC_R27
977 swi r28, r11, CC_R28
978 swi r29, r11, CC_R29
979 swi r30, r11, CC_R30
980 /* special purpose registers */
981 mfs r12, rmsr
982 nop
983 swi r12, r11, CC_MSR
984 mfs r12, rear
985 nop
986 swi r12, r11, CC_EAR
987 mfs r12, resr
988 nop
989 swi r12, r11, CC_ESR
990 mfs r12, rfsr
991 nop
992 swi r12, r11, CC_FSR
993
Michal Simekb1d70c62010-01-22 10:24:06 +0100994 /* update r31, the current-give me pointer to task which will be next */
995 lwi CURRENT_TASK, r6, TI_TASK
Michal Simekca545022009-05-26 16:30:21 +0200996 /* stored it to current_save too */
Michal Simekb1d70c62010-01-22 10:24:06 +0100997 swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE)
Michal Simekca545022009-05-26 16:30:21 +0200998
999 /* get new process' cpu context and restore */
1000 /* give me start where start context of next task */
1001 addik r11, r6, TI_CPU_CONTEXT
1002
1003 /* non-volatile registers */
1004 lwi r30, r11, CC_R30
1005 lwi r29, r11, CC_R29
1006 lwi r28, r11, CC_R28
1007 lwi r27, r11, CC_R27
1008 lwi r26, r11, CC_R26
1009 lwi r25, r11, CC_R25
1010 lwi r24, r11, CC_R24
1011 lwi r23, r11, CC_R23
1012 lwi r22, r11, CC_R22
1013 lwi r21, r11, CC_R21
1014 lwi r20, r11, CC_R20
1015 lwi r19, r11, CC_R19
1016 /* dedicated registers */
1017 lwi r18, r11, CC_R18
1018 lwi r17, r11, CC_R17
1019 lwi r16, r11, CC_R16
1020 lwi r15, r11, CC_R15
1021 lwi r14, r11, CC_R14
1022 lwi r13, r11, CC_R13
1023 /* skip volatile registers */
1024 lwi r2, r11, CC_R2
1025 lwi r1, r11, CC_R1
1026
1027 /* special purpose registers */
1028 lwi r12, r11, CC_FSR
1029 mts rfsr, r12
1030 nop
1031 lwi r12, r11, CC_MSR
1032 mts rmsr, r12
1033 nop
1034
1035 rtsd r15, 8
1036 nop
1037
1038ENTRY(_reset)
1039 brai 0x70; /* Jump back to FS-boot */
1040
1041ENTRY(_break)
1042 mfs r5, rmsr
1043 nop
1044 swi r5, r0, 0x250 + TOPHYS(r0_ram)
1045 mfs r5, resr
1046 nop
1047 swi r5, r0, 0x254 + TOPHYS(r0_ram)
1048 bri 0
1049
1050 /* These are compiled and loaded into high memory, then
1051 * copied into place in mach_early_setup */
1052 .section .init.ivt, "ax"
1053 .org 0x0
1054 /* this is very important - here is the reset vector */
1055 /* in current MMU branch you don't care what is here - it is
1056 * used from bootloader site - but this is correct for FS-BOOT */
1057 brai 0x70
1058 nop
1059 brai TOPHYS(_user_exception); /* syscall handler */
1060 brai TOPHYS(_interrupt); /* Interrupt handler */
1061 brai TOPHYS(_break); /* nmi trap handler */
1062 brai TOPHYS(_hw_exception_handler); /* HW exception handler */
1063
1064 .org 0x60
1065 brai TOPHYS(_debug_exception); /* debug trap handler*/
1066
1067.section .rodata,"a"
1068#include "syscall_table.S"
1069
1070syscall_table_size=(.-sys_call_table)
1071
Steven J. Magnanice3266c2010-04-27 12:37:54 -05001072type_SYSCALL:
1073 .ascii "SYSCALL\0"
1074type_IRQ:
1075 .ascii "IRQ\0"
1076type_IRQ_PREEMPT:
1077 .ascii "IRQ (PREEMPTED)\0"
1078type_SYSCALL_PREEMPT:
1079 .ascii " SYSCALL (PREEMPTED)\0"
1080
1081 /*
1082 * Trap decoding for stack unwinder
1083 * Tuples are (start addr, end addr, string)
1084 * If return address lies on [start addr, end addr],
1085 * unwinder displays 'string'
1086 */
1087
1088 .align 4
1089.global microblaze_trap_handlers
1090microblaze_trap_handlers:
1091 /* Exact matches come first */
1092 .word ret_from_trap; .word ret_from_trap ; .word type_SYSCALL
1093 .word ret_from_irq ; .word ret_from_irq ; .word type_IRQ
1094 /* Fuzzy matches go here */
1095 .word ret_from_irq ; .word no_intr_resched ; .word type_IRQ_PREEMPT
1096 .word ret_from_trap; .word TRAP_return ; .word type_SYSCALL_PREEMPT
1097 /* End of table */
1098 .word 0 ; .word 0 ; .word 0