blob: 4c06e1a46a25f814cda68124f9c4b3ff53151b85 [file] [log] [blame]
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)); \
Michal Simek287503f2010-06-22 18:16:07 +0200282 /* 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; \
Michal Simeke5d2af22010-06-22 17:58:26 +0200286 SAVE_REGS \
Michal Simeke5d2af22010-06-22 17:58:26 +0200287 brid 2f; \
Michal Simekda233552010-06-22 18:02:06 +0200288 swi r1, r1, PTO+PT_MODE; \
Michal Simeke5d2af22010-06-22 17:58:26 +02002891: /* 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 */ \
Michal Simek287503f2010-06-22 18:16:07 +0200293 /* 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; \
Michal Simeke5d2af22010-06-22 17:58:26 +0200298 SAVE_REGS \
Michal Simeke5d2af22010-06-22 17:58:26 +0200299 lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \
300 swi r11, r1, PTO+PT_R1; /* Store user SP. */ \
Michal Simeke7741072010-06-22 18:00:35 +0200301 swi r0, r1, PTO + PT_MODE; /* Was in user-mode. */ \
Michal Simeke5d2af22010-06-22 17:58:26 +0200302 /* MS: I am clearing UMS even in case when I come from kernel space */ \
303 clear_ums; \
3042: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
305
Michal Simekca545022009-05-26 16:30:21 +0200306.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 */
320C_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 */
Michal Simekca545022009-05-26 16:30:21 +0200323
Michal Simek653e4472010-06-22 14:51:45 +0200324 mfs r1, rmsr
Michal Simek5c0d72b2010-06-22 14:00:12 +0200325 nop
Michal Simek653e4472010-06-22 14:51:45 +0200326 andi r1, r1, MSR_UMS
327 bnei r1, 1f
Michal Simek5c0d72b2010-06-22 14:00:12 +0200328
329/* Kernel-mode state save - kernel execve */
Michal Simek653e4472010-06-22 14:51:45 +0200330 lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/
331 tophys(r1,r1);
Michal Simekca545022009-05-26 16:30:21 +0200332
333 addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
334 SAVE_REGS
335
Michal Simek77f6d222010-06-22 16:39:56 +0200336 swi r1, r1, PTO + PT_MODE; /* pt_regs -> kernel mode */
Michal Simekca545022009-05-26 16:30:21 +0200337 brid 2f;
338 nop; /* Fill delay slot */
339
340/* User-mode state save. */
3411:
Michal Simekca545022009-05-26 16:30:21 +0200342 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
Michal Simek77f6d222010-06-22 16:39:56 +0200352 swi r0, r1, PTO + PT_MODE; /* Was in user-mode. */
Michal Simekca545022009-05-26 16:30:21 +0200353 lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
354 swi r11, r1, PTO+PT_R1; /* Store user SP. */
Michal Simek25f6e592010-06-22 18:29:05 +0200355 clear_ums;
Michal Simekb1d70c62010-01-22 10:24:06 +01003562: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
Michal Simekca545022009-05-26 16:30:21 +0200357 /* Save away the syscall number. */
358 swi r12, r1, PTO+PT_R0;
359 tovirt(r1,r1)
360
Michal Simekca545022009-05-26 16:30:21 +0200361/* where the trap should return need -8 to adjust for rtsd r15, 8*/
362/* Jump to the appropriate function for the system call number in r12
363 * (r12 is not preserved), or return an error if r12 is not valid. The LP
364 * register should point to the location where
365 * the called function should return. [note that MAKE_SYS_CALL uses label 1] */
Michal Simek23575482009-08-24 13:26:04 +0200366
Michal Simek25f6e592010-06-22 18:29:05 +0200367 /* Step into virtual mode */
368 rtbd r0, 3f
Michal Simek23575482009-08-24 13:26:04 +0200369 nop
3703:
Michal Simekb1d70c62010-01-22 10:24:06 +0100371 lwi r11, CURRENT_TASK, TS_THREAD_INFO /* get thread info */
Michal Simek23575482009-08-24 13:26:04 +0200372 lwi r11, r11, TI_FLAGS /* get flags in thread info */
373 andi r11, r11, _TIF_WORK_SYSCALL_MASK
374 beqi r11, 4f
375
376 addik r3, r0, -ENOSYS
377 swi r3, r1, PTO + PT_R3
378 brlid r15, do_syscall_trace_enter
379 addik r5, r1, PTO + PT_R0
380
381 # do_syscall_trace_enter returns the new syscall nr.
382 addk r12, r0, r3
383 lwi r5, r1, PTO+PT_R5;
384 lwi r6, r1, PTO+PT_R6;
385 lwi r7, r1, PTO+PT_R7;
386 lwi r8, r1, PTO+PT_R8;
387 lwi r9, r1, PTO+PT_R9;
388 lwi r10, r1, PTO+PT_R10;
3894:
390/* Jump to the appropriate function for the system call number in r12
391 * (r12 is not preserved), or return an error if r12 is not valid.
392 * The LP register should point to the location where the called function
393 * should return. [note that MAKE_SYS_CALL uses label 1] */
394 /* See if the system call number is valid */
Michal Simekca545022009-05-26 16:30:21 +0200395 addi r11, r12, -__NR_syscalls;
Michal Simek23575482009-08-24 13:26:04 +0200396 bgei r11,5f;
Michal Simekca545022009-05-26 16:30:21 +0200397 /* Figure out which function to use for this system call. */
398 /* Note Microblaze barrel shift is optional, so don't rely on it */
399 add r12, r12, r12; /* convert num -> ptr */
400 add r12, r12, r12;
401
Michal Simek11d51362009-12-07 08:21:34 +0100402#ifdef DEBUG
Michal Simekca545022009-05-26 16:30:21 +0200403 /* Trac syscalls and stored them to r0_ram */
Michal Simek23575482009-08-24 13:26:04 +0200404 lwi r3, r12, 0x400 + r0_ram
Michal Simekca545022009-05-26 16:30:21 +0200405 addi r3, r3, 1
Michal Simek23575482009-08-24 13:26:04 +0200406 swi r3, r12, 0x400 + r0_ram
Michal Simek11d51362009-12-07 08:21:34 +0100407#endif
Michal Simekca545022009-05-26 16:30:21 +0200408
Michal Simek23575482009-08-24 13:26:04 +0200409 # Find and jump into the syscall handler.
410 lwi r12, r12, sys_call_table
411 /* where the trap should return need -8 to adjust for rtsd r15, 8 */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200412 addi r15, r0, ret_from_trap-8
Michal Simek23575482009-08-24 13:26:04 +0200413 bra r12
414
Michal Simekca545022009-05-26 16:30:21 +0200415 /* The syscall number is invalid, return an error. */
Michal Simek23575482009-08-24 13:26:04 +02004165:
Michal Simek9814cc12010-06-22 18:09:29 +0200417 rtsd r15, 8; /* looks like a normal subroutine return */
Michal Simekca545022009-05-26 16:30:21 +0200418 addi r3, r0, -ENOSYS;
Michal Simekca545022009-05-26 16:30:21 +0200419
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) */
Michal Simekca545022009-05-26 16:30:21 +0200495 brid do_fork /* Do real work (tail-call) */
Michal Simek9814cc12010-06-22 18:09:29 +0200496 add r10, r0, r0; /* Arg 5: (unused) */
Michal Simekca545022009-05-26 16:30:21 +0200497
498/* This the initial entry point for a new child thread, with an appropriate
499 stack in place that makes it look the the child is in the middle of an
500 syscall. This function is actually `returned to' from switch_thread
501 (copy_thread makes ret_from_fork the return address in each new thread's
502 saved context). */
503C_ENTRY(ret_from_fork):
504 bralid r15, schedule_tail; /* ...which is schedule_tail's arg */
505 add r3, r5, r0; /* switch_thread returns the prev task */
506 /* ( in the delay slot ) */
Michal Simekca545022009-05-26 16:30:21 +0200507 brid ret_from_trap; /* Do normal trap return */
Michal Simek9814cc12010-06-22 18:09:29 +0200508 add r3, r0, r0; /* Child's fork call should return 0. */
Michal Simekca545022009-05-26 16:30:21 +0200509
Arnd Bergmanne5135882009-06-18 19:55:30 +0200510C_ENTRY(sys_vfork):
511 brid microblaze_vfork /* Do real work (tail-call) */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200512 addik r5, r1, PTO
Michal Simekca545022009-05-26 16:30:21 +0200513
Arnd Bergmanne5135882009-06-18 19:55:30 +0200514C_ENTRY(sys_clone):
Michal Simekca545022009-05-26 16:30:21 +0200515 bnei r6, 1f; /* See if child SP arg (arg 1) is 0. */
Michal Simek570e3e22010-06-04 13:06:27 +0200516 lwi r6, r1, PTO + PT_R1; /* If so, use paret's stack ptr */
Michal Simekb9ea77e2010-07-28 12:40:02 +02005171: addik r7, r1, PTO; /* Arg 2: parent context */
518 add r8, r0, r0; /* Arg 3: (unused) */
519 add r9, r0, r0; /* Arg 4: (unused) */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200520 brid do_fork /* Do real work (tail-call) */
Michal Simek9814cc12010-06-22 18:09:29 +0200521 add r10, r0, r0; /* Arg 5: (unused) */
Michal Simekca545022009-05-26 16:30:21 +0200522
Arnd Bergmanne5135882009-06-18 19:55:30 +0200523C_ENTRY(sys_execve):
Arnd Bergmanne5135882009-06-18 19:55:30 +0200524 brid microblaze_execve; /* Do real work (tail-call).*/
Michal Simek9814cc12010-06-22 18:09:29 +0200525 addik r8, r1, PTO; /* add user context as 4th arg */
Michal Simekca545022009-05-26 16:30:21 +0200526
Michal Simekca545022009-05-26 16:30:21 +0200527C_ENTRY(sys_rt_sigreturn_wrapper):
528 swi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
529 swi r4, r1, PTO+PT_R4;
Michal Simekca545022009-05-26 16:30:21 +0200530 brlid r15, sys_rt_sigreturn /* Do real work */
Michal Simek9814cc12010-06-22 18:09:29 +0200531 addik r5, r1, PTO; /* add user context as 1st arg */
Michal Simekca545022009-05-26 16:30:21 +0200532 lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
533 lwi r4, r1, PTO+PT_R4;
534 bri ret_from_trap /* fall through will not work here due to align */
535 nop;
536
537/*
538 * HW EXCEPTION rutine start
539 */
Michal Simekca545022009-05-26 16:30:21 +0200540C_ENTRY(full_exception_trap):
Michal Simekca545022009-05-26 16:30:21 +0200541 /* adjust exception address for privileged instruction
542 * for finding where is it */
543 addik r17, r17, -4
544 SAVE_STATE /* Save registers */
Michal Simek06a54602010-06-22 16:22:01 +0200545 /* PC, before IRQ/trap - this is one instruction above */
546 swi r17, r1, PTO+PT_PC;
547 tovirt(r1,r1)
Michal Simekca545022009-05-26 16:30:21 +0200548 /* FIXME this can be store directly in PT_ESR reg.
549 * I tested it but there is a fault */
550 /* where the trap should return need -8 to adjust for rtsd r15, 8 */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200551 addik r15, r0, ret_from_exc - 8
Michal Simekca545022009-05-26 16:30:21 +0200552 mfs r6, resr
553 nop
554 mfs r7, rfsr; /* save FSR */
555 nop
Michal Simek131e4e92009-09-28 08:50:53 +0200556 mts rfsr, r0; /* Clear sticky fsr */
557 nop
Michal Simekc318d482010-06-22 16:25:31 +0200558 rted r0, full_exception
Michal Simek9814cc12010-06-22 18:09:29 +0200559 addik r5, r1, PTO /* parameter struct pt_regs * regs */
Michal Simekca545022009-05-26 16:30:21 +0200560
561/*
562 * Unaligned data trap.
563 *
564 * Unaligned data trap last on 4k page is handled here.
565 *
566 * Trap entered via exception, so EE bit is set, and interrupts
567 * are masked. This is nice, means we don't have to CLI before state save
568 *
569 * The assembler routine is in "arch/microblaze/kernel/hw_exception_handler.S"
570 */
571C_ENTRY(unaligned_data_trap):
Michal Simek8b110d12010-06-17 16:03:05 +0200572 /* MS: I have to save r11 value and then restore it because
573 * set_bit, clear_eip, set_ee use r11 as temp register if MSR
574 * instructions are not used. We don't need to do if MSR instructions
575 * are used and they use r0 instead of r11.
576 * I am using ENTRY_SP which should be primary used only for stack
577 * pointer saving. */
578 swi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
579 set_bip; /* equalize initial state for all possible entries */
580 clear_eip;
581 set_ee;
582 lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
Michal Simekca545022009-05-26 16:30:21 +0200583 SAVE_STATE /* Save registers.*/
Michal Simek06a54602010-06-22 16:22:01 +0200584 /* PC, before IRQ/trap - this is one instruction above */
585 swi r17, r1, PTO+PT_PC;
586 tovirt(r1,r1)
Michal Simekca545022009-05-26 16:30:21 +0200587 /* where the trap should return need -8 to adjust for rtsd r15, 8 */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200588 addik r15, r0, ret_from_exc-8
Michal Simekca545022009-05-26 16:30:21 +0200589 mfs r3, resr /* ESR */
590 nop
591 mfs r4, rear /* EAR */
592 nop
Michal Simekc318d482010-06-22 16:25:31 +0200593 rtbd r0, _unaligned_data_exception
Michal Simekb9ea77e2010-07-28 12:40:02 +0200594 addik r7, r1, PTO /* parameter struct pt_regs * regs */
Michal Simekca545022009-05-26 16:30:21 +0200595
596/*
597 * Page fault traps.
598 *
599 * If the real exception handler (from hw_exception_handler.S) didn't find
600 * the mapping for the process, then we're thrown here to handle such situation.
601 *
602 * Trap entered via exceptions, so EE bit is set, and interrupts
603 * are masked. This is nice, means we don't have to CLI before state save
604 *
605 * Build a standard exception frame for TLB Access errors. All TLB exceptions
606 * will bail out to this point if they can't resolve the lightweight TLB fault.
607 *
608 * The C function called is in "arch/microblaze/mm/fault.c", declared as:
609 * void do_page_fault(struct pt_regs *regs,
610 * unsigned long address,
611 * unsigned long error_code)
612 */
613/* data and intruction trap - which is choose is resolved int fault.c */
614C_ENTRY(page_fault_data_trap):
Michal Simekca545022009-05-26 16:30:21 +0200615 SAVE_STATE /* Save registers.*/
Michal Simek06a54602010-06-22 16:22:01 +0200616 /* PC, before IRQ/trap - this is one instruction above */
617 swi r17, r1, PTO+PT_PC;
618 tovirt(r1,r1)
Michal Simekca545022009-05-26 16:30:21 +0200619 /* where the trap should return need -8 to adjust for rtsd r15, 8 */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200620 addik r15, r0, ret_from_exc-8
Michal Simekca545022009-05-26 16:30:21 +0200621 mfs r6, rear /* parameter unsigned long address */
622 nop
623 mfs r7, resr /* parameter unsigned long error_code */
624 nop
Michal Simekc318d482010-06-22 16:25:31 +0200625 rted r0, do_page_fault
Michal Simek9814cc12010-06-22 18:09:29 +0200626 addik r5, r1, PTO /* parameter struct pt_regs * regs */
Michal Simekca545022009-05-26 16:30:21 +0200627
628C_ENTRY(page_fault_instr_trap):
Michal Simekca545022009-05-26 16:30:21 +0200629 SAVE_STATE /* Save registers.*/
Michal Simek06a54602010-06-22 16:22:01 +0200630 /* PC, before IRQ/trap - this is one instruction above */
631 swi r17, r1, PTO+PT_PC;
632 tovirt(r1,r1)
Michal Simekca545022009-05-26 16:30:21 +0200633 /* where the trap should return need -8 to adjust for rtsd r15, 8 */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200634 addik r15, r0, ret_from_exc-8
Michal Simekca545022009-05-26 16:30:21 +0200635 mfs r6, rear /* parameter unsigned long address */
636 nop
637 ori r7, r0, 0 /* parameter unsigned long error_code */
Michal Simek9814cc12010-06-22 18:09:29 +0200638 rted r0, do_page_fault
639 addik r5, r1, PTO /* parameter struct pt_regs * regs */
Michal Simekca545022009-05-26 16:30:21 +0200640
641/* Entry point used to return from an exception. */
642C_ENTRY(ret_from_exc):
Michal Simek77f6d222010-06-22 16:39:56 +0200643 lwi r11, r1, PTO + PT_MODE;
Michal Simekca545022009-05-26 16:30:21 +0200644 bnei r11, 2f; /* See if returning to kernel mode, */
645 /* ... if so, skip resched &c. */
646
647 /* We're returning to user mode, so check for various conditions that
648 trigger rescheduling. */
Michal Simekb1d70c62010-01-22 10:24:06 +0100649 lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
Michal Simekca545022009-05-26 16:30:21 +0200650 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
651 andi r11, r11, _TIF_NEED_RESCHED;
652 beqi r11, 5f;
653
654/* Call the scheduler before returning from a syscall/trap. */
655 bralid r15, schedule; /* Call scheduler */
656 nop; /* delay slot */
657
658 /* Maybe handle a signal */
Michal Simekb1d70c62010-01-22 10:24:06 +01006595: lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
Michal Simekca545022009-05-26 16:30:21 +0200660 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
661 andi r11, r11, _TIF_SIGPENDING;
662 beqi r11, 1f; /* Signals to handle, handle them */
663
664 /*
665 * Handle a signal return; Pending signals should be in r18.
666 *
667 * Not all registers are saved by the normal trap/interrupt entry
668 * points (for instance, call-saved registers (because the normal
669 * C-compiler calling sequence in the kernel makes sure they're
670 * preserved), and call-clobbered registers in the case of
671 * traps), but signal handlers may want to examine or change the
672 * complete register state. Here we save anything not saved by
673 * the normal entry sequence, so that it may be safely restored
Michal Simek36f60952010-06-22 13:27:43 +0200674 * (in a possibly modified form) after do_signal returns. */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200675 addik r5, r1, PTO; /* Arg 1: struct pt_regs *regs */
Michal Simekca545022009-05-26 16:30:21 +0200676 addi r7, r0, 0; /* Arg 3: int in_syscall */
677 bralid r15, do_signal; /* Handle any signals */
Michal Simek841d6e82010-01-22 14:28:36 +0100678 add r6, r0, r0; /* Arg 2: sigset_t *oldset */
Michal Simekca545022009-05-26 16:30:21 +0200679
680/* Finally, return to user state. */
Michal Simek96014cc2010-06-22 14:05:43 +02006811: set_bip; /* Ints masked for state restore */
Michal Simek8633beb2010-02-22 13:24:43 +0100682 swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
Michal Simekca545022009-05-26 16:30:21 +0200683 VM_OFF;
684 tophys(r1,r1);
685
Michal Simekca545022009-05-26 16:30:21 +0200686 RESTORE_REGS;
687 addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
688
689 lwi r1, r1, PT_R1 - PT_SIZE; /* Restore user stack pointer. */
690 bri 6f;
691/* Return to kernel state. */
Michal Simek96014cc2010-06-22 14:05:43 +02006922: set_bip; /* Ints masked for state restore */
693 VM_OFF;
Michal Simekca545022009-05-26 16:30:21 +0200694 tophys(r1,r1);
Michal Simekca545022009-05-26 16:30:21 +0200695 RESTORE_REGS;
696 addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
697
698 tovirt(r1,r1);
6996:
700EXC_return: /* Make global symbol for debugging */
701 rtbd r14, 0; /* Instructions to return from an IRQ */
702 nop;
703
704/*
705 * HW EXCEPTION rutine end
706 */
707
708/*
709 * Hardware maskable interrupts.
710 *
711 * The stack-pointer (r1) should have already been saved to the memory
712 * location PER_CPU(ENTRY_SP).
713 */
714C_ENTRY(_interrupt):
715/* MS: we are in physical address */
716/* Save registers, switch to proper stack, convert SP to virtual.*/
717 swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP))
Michal Simekca545022009-05-26 16:30:21 +0200718 /* MS: See if already in kernel mode. */
Michal Simek653e4472010-06-22 14:51:45 +0200719 mfs r1, rmsr
Michal Simek5c0d72b2010-06-22 14:00:12 +0200720 nop
Michal Simek653e4472010-06-22 14:51:45 +0200721 andi r1, r1, MSR_UMS
722 bnei r1, 1f
Michal Simekca545022009-05-26 16:30:21 +0200723
724/* Kernel-mode state save. */
Michal Simek653e4472010-06-22 14:51:45 +0200725 lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP))
726 tophys(r1,r1); /* MS: I have in r1 physical address where stack is */
Michal Simekca545022009-05-26 16:30:21 +0200727 /* save registers */
728/* MS: Make room on the stack -> activation record */
729 addik r1, r1, -STATE_SAVE_SIZE;
Michal Simekca545022009-05-26 16:30:21 +0200730 SAVE_REGS
Michal Simek77f6d222010-06-22 16:39:56 +0200731 swi r1, r1, PTO + PT_MODE; /* 0 - user mode, 1 - kernel mode */
Michal Simekca545022009-05-26 16:30:21 +0200732 brid 2f;
733 nop; /* MS: Fill delay slot */
734
7351:
736/* User-mode state save. */
Michal Simekca545022009-05-26 16:30:21 +0200737 /* MS: get the saved current */
738 lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
739 tophys(r1,r1);
740 lwi r1, r1, TS_THREAD_INFO;
741 addik r1, r1, THREAD_SIZE;
742 tophys(r1,r1);
743 /* save registers */
744 addik r1, r1, -STATE_SAVE_SIZE;
Michal Simekca545022009-05-26 16:30:21 +0200745 SAVE_REGS
746 /* calculate mode */
747 swi r0, r1, PTO + PT_MODE;
748 lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
749 swi r11, r1, PTO+PT_R1;
Michal Simekca545022009-05-26 16:30:21 +02007502:
Michal Simekb1d70c62010-01-22 10:24:06 +0100751 lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
Michal Simekca545022009-05-26 16:30:21 +0200752 tovirt(r1,r1)
Michal Simekb9ea77e2010-07-28 12:40:02 +0200753 addik r5, r1, PTO;
Michal Simekca545022009-05-26 16:30:21 +0200754 set_vms;
Michal Simekb9ea77e2010-07-28 12:40:02 +0200755 addik r11, r0, do_IRQ;
756 addik r15, r0, irq_call;
Michal Simekca545022009-05-26 16:30:21 +0200757irq_call:rtbd r11, 0;
758 nop;
759
760/* MS: we are in virtual mode */
761ret_from_irq:
762 lwi r11, r1, PTO + PT_MODE;
763 bnei r11, 2f;
764
Michal Simekb1d70c62010-01-22 10:24:06 +0100765 lwi r11, CURRENT_TASK, TS_THREAD_INFO;
Michal Simekca545022009-05-26 16:30:21 +0200766 lwi r11, r11, TI_FLAGS; /* MS: get flags from thread info */
767 andi r11, r11, _TIF_NEED_RESCHED;
768 beqi r11, 5f
769 bralid r15, schedule;
770 nop; /* delay slot */
771
772 /* Maybe handle a signal */
Michal Simekb1d70c62010-01-22 10:24:06 +01007735: lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* MS: get thread info */
Michal Simekca545022009-05-26 16:30:21 +0200774 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
775 andi r11, r11, _TIF_SIGPENDING;
776 beqid r11, no_intr_resched
777/* Handle a signal return; Pending signals should be in r18. */
778 addi r7, r0, 0; /* Arg 3: int in_syscall */
Michal Simekb9ea77e2010-07-28 12:40:02 +0200779 addik r5, r1, PTO; /* Arg 1: struct pt_regs *regs */
Michal Simekca545022009-05-26 16:30:21 +0200780 bralid r15, do_signal; /* Handle any signals */
781 add r6, r0, r0; /* Arg 2: sigset_t *oldset */
782
783/* Finally, return to user state. */
784no_intr_resched:
785 /* Disable interrupts, we are now committed to the state restore */
786 disable_irq
Michal Simek8633beb2010-02-22 13:24:43 +0100787 swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE);
Michal Simekca545022009-05-26 16:30:21 +0200788 VM_OFF;
789 tophys(r1,r1);
Michal Simekca545022009-05-26 16:30:21 +0200790 RESTORE_REGS
791 addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */
792 lwi r1, r1, PT_R1 - PT_SIZE;
793 bri 6f;
794/* MS: Return to kernel state. */
Michal Simek77753792010-01-12 09:55:10 +01007952:
796#ifdef CONFIG_PREEMPT
Michal Simekb1d70c62010-01-22 10:24:06 +0100797 lwi r11, CURRENT_TASK, TS_THREAD_INFO;
Michal Simek77753792010-01-12 09:55:10 +0100798 /* MS: get preempt_count from thread info */
799 lwi r5, r11, TI_PREEMPT_COUNT;
800 bgti r5, restore;
801
802 lwi r5, r11, TI_FLAGS; /* get flags in thread info */
803 andi r5, r5, _TIF_NEED_RESCHED;
804 beqi r5, restore /* if zero jump over */
805
806preempt:
807 /* interrupts are off that's why I am calling preempt_chedule_irq */
808 bralid r15, preempt_schedule_irq
809 nop
Michal Simekb1d70c62010-01-22 10:24:06 +0100810 lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
Michal Simek77753792010-01-12 09:55:10 +0100811 lwi r5, r11, TI_FLAGS; /* get flags in thread info */
812 andi r5, r5, _TIF_NEED_RESCHED;
813 bnei r5, preempt /* if non zero jump to resched */
814restore:
815#endif
816 VM_OFF /* MS: turn off MMU */
Michal Simekca545022009-05-26 16:30:21 +0200817 tophys(r1,r1)
Michal Simekca545022009-05-26 16:30:21 +0200818 RESTORE_REGS
819 addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */
820 tovirt(r1,r1);
8216:
822IRQ_return: /* MS: Make global symbol for debugging */
823 rtid r14, 0
824 nop
825
826/*
827 * `Debug' trap
828 * We enter dbtrap in "BIP" (breakpoint) mode.
829 * So we exit the breakpoint mode with an 'rtbd' and proceed with the
830 * original dbtrap.
831 * however, wait to save state first
832 */
833C_ENTRY(_debug_exception):
834 /* BIP bit is set on entry, no interrupts can occur */
835 swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP))
836
Michal Simek653e4472010-06-22 14:51:45 +0200837 mfs r1, rmsr
Michal Simek5c0d72b2010-06-22 14:00:12 +0200838 nop
Michal Simek653e4472010-06-22 14:51:45 +0200839 andi r1, r1, MSR_UMS
840 bnei r1, 1f
Michal Simekca545022009-05-26 16:30:21 +0200841 /* Kernel-mode state save. */
Michal Simek653e4472010-06-22 14:51:45 +0200842 lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/
843 tophys(r1,r1);
Michal Simekca545022009-05-26 16:30:21 +0200844
845 addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
Michal Simekca545022009-05-26 16:30:21 +0200846 SAVE_REGS;
847
Michal Simek77f6d222010-06-22 16:39:56 +0200848 swi r1, r1, PTO + PT_MODE;
Michal Simekca545022009-05-26 16:30:21 +0200849 brid 2f;
850 nop; /* Fill delay slot */
8511: /* User-mode state save. */
Michal Simekca545022009-05-26 16:30:21 +0200852 lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
853 tophys(r1,r1);
854 lwi r1, r1, TS_THREAD_INFO; /* get the thread info */
855 addik r1, r1, THREAD_SIZE; /* calculate kernel stack pointer */
856 tophys(r1,r1);
857
858 addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
Michal Simekca545022009-05-26 16:30:21 +0200859 SAVE_REGS;
860
Michal Simek77f6d222010-06-22 16:39:56 +0200861 swi r0, r1, PTO + PT_MODE; /* Was in user-mode. */
Michal Simekca545022009-05-26 16:30:21 +0200862 lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
863 swi r11, r1, PTO+PT_R1; /* Store user SP. */
Michal Simek653e4472010-06-22 14:51:45 +02008642:
Michal Simekca545022009-05-26 16:30:21 +0200865 tovirt(r1,r1)
866
Michal Simek06b28642010-06-22 15:25:24 +0200867 set_vms;
Michal Simekca545022009-05-26 16:30:21 +0200868 addi r5, r0, SIGTRAP /* send the trap signal */
869 add r6, r0, CURRENT_TASK; /* Get current task ptr into r11 */
870 addk r7, r0, r0 /* 3rd param zero */
Michal Simek06b28642010-06-22 15:25:24 +0200871dbtrap_call: rtbd r0, send_sig;
Michal Simekb9ea77e2010-07-28 12:40:02 +0200872 addik r15, r0, dbtrap_call;
Michal Simekca545022009-05-26 16:30:21 +0200873
874 set_bip; /* Ints masked for state restore*/
Michal Simek77f6d222010-06-22 16:39:56 +0200875 lwi r11, r1, PTO + PT_MODE;
Michal Simekca545022009-05-26 16:30:21 +0200876 bnei r11, 2f;
877
878 /* Get current task ptr into r11 */
Michal Simekb1d70c62010-01-22 10:24:06 +0100879 lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
Michal Simekca545022009-05-26 16:30:21 +0200880 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
881 andi r11, r11, _TIF_NEED_RESCHED;
882 beqi r11, 5f;
883
884/* Call the scheduler before returning from a syscall/trap. */
885
886 bralid r15, schedule; /* Call scheduler */
887 nop; /* delay slot */
888 /* XXX Is PT_DTRACE handling needed here? */
889 /* XXX m68knommu also checks TASK_STATE & TASK_COUNTER here. */
890
891 /* Maybe handle a signal */
Michal Simekb1d70c62010-01-22 10:24:06 +01008925: lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
Michal Simekca545022009-05-26 16:30:21 +0200893 lwi r11, r11, TI_FLAGS; /* get flags in thread info */
894 andi r11, r11, _TIF_SIGPENDING;
895 beqi r11, 1f; /* Signals to handle, handle them */
896
897/* Handle a signal return; Pending signals should be in r18. */
898 /* Not all registers are saved by the normal trap/interrupt entry
899 points (for instance, call-saved registers (because the normal
900 C-compiler calling sequence in the kernel makes sure they're
901 preserved), and call-clobbered registers in the case of
902 traps), but signal handlers may want to examine or change the
903 complete register state. Here we save anything not saved by
904 the normal entry sequence, so that it may be safely restored
905 (in a possibly modified form) after do_signal returns. */
906
Michal Simekb9ea77e2010-07-28 12:40:02 +0200907 addik r5, r1, PTO; /* Arg 1: struct pt_regs *regs */
Michal Simekca545022009-05-26 16:30:21 +0200908 addi r7, r0, 0; /* Arg 3: int in_syscall */
909 bralid r15, do_signal; /* Handle any signals */
Michal Simek841d6e82010-01-22 14:28:36 +0100910 add r6, r0, r0; /* Arg 2: sigset_t *oldset */
Michal Simekca545022009-05-26 16:30:21 +0200911
912
913/* Finally, return to user state. */
Michal Simek5c0d72b2010-06-22 14:00:12 +02009141:
Michal Simek8633beb2010-02-22 13:24:43 +0100915 swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
Michal Simekca545022009-05-26 16:30:21 +0200916 VM_OFF;
917 tophys(r1,r1);
918
Michal Simekca545022009-05-26 16:30:21 +0200919 RESTORE_REGS
920 addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
921
922
923 lwi r1, r1, PT_R1 - PT_SIZE;
924 /* Restore user stack pointer. */
925 bri 6f;
926
927/* Return to kernel state. */
9282: VM_OFF;
929 tophys(r1,r1);
Michal Simekca545022009-05-26 16:30:21 +0200930 RESTORE_REGS
931 addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */
932
933 tovirt(r1,r1);
9346:
935DBTRAP_return: /* Make global symbol for debugging */
936 rtbd r14, 0; /* Instructions to return from an IRQ */
937 nop;
938
939
940
941ENTRY(_switch_to)
942 /* prepare return value */
Michal Simekb1d70c62010-01-22 10:24:06 +0100943 addk r3, r0, CURRENT_TASK
Michal Simekca545022009-05-26 16:30:21 +0200944
945 /* save registers in cpu_context */
946 /* use r11 and r12, volatile registers, as temp register */
947 /* give start of cpu_context for previous process */
948 addik r11, r5, TI_CPU_CONTEXT
949 swi r1, r11, CC_R1
950 swi r2, r11, CC_R2
951 /* skip volatile registers.
952 * they are saved on stack when we jumped to _switch_to() */
953 /* dedicated registers */
954 swi r13, r11, CC_R13
955 swi r14, r11, CC_R14
956 swi r15, r11, CC_R15
957 swi r16, r11, CC_R16
958 swi r17, r11, CC_R17
959 swi r18, r11, CC_R18
960 /* save non-volatile registers */
961 swi r19, r11, CC_R19
962 swi r20, r11, CC_R20
963 swi r21, r11, CC_R21
964 swi r22, r11, CC_R22
965 swi r23, r11, CC_R23
966 swi r24, r11, CC_R24
967 swi r25, r11, CC_R25
968 swi r26, r11, CC_R26
969 swi r27, r11, CC_R27
970 swi r28, r11, CC_R28
971 swi r29, r11, CC_R29
972 swi r30, r11, CC_R30
973 /* special purpose registers */
974 mfs r12, rmsr
975 nop
976 swi r12, r11, CC_MSR
977 mfs r12, rear
978 nop
979 swi r12, r11, CC_EAR
980 mfs r12, resr
981 nop
982 swi r12, r11, CC_ESR
983 mfs r12, rfsr
984 nop
985 swi r12, r11, CC_FSR
986
Michal Simekb1d70c62010-01-22 10:24:06 +0100987 /* update r31, the current-give me pointer to task which will be next */
988 lwi CURRENT_TASK, r6, TI_TASK
Michal Simekca545022009-05-26 16:30:21 +0200989 /* stored it to current_save too */
Michal Simekb1d70c62010-01-22 10:24:06 +0100990 swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE)
Michal Simekca545022009-05-26 16:30:21 +0200991
992 /* get new process' cpu context and restore */
993 /* give me start where start context of next task */
994 addik r11, r6, TI_CPU_CONTEXT
995
996 /* non-volatile registers */
997 lwi r30, r11, CC_R30
998 lwi r29, r11, CC_R29
999 lwi r28, r11, CC_R28
1000 lwi r27, r11, CC_R27
1001 lwi r26, r11, CC_R26
1002 lwi r25, r11, CC_R25
1003 lwi r24, r11, CC_R24
1004 lwi r23, r11, CC_R23
1005 lwi r22, r11, CC_R22
1006 lwi r21, r11, CC_R21
1007 lwi r20, r11, CC_R20
1008 lwi r19, r11, CC_R19
1009 /* dedicated registers */
1010 lwi r18, r11, CC_R18
1011 lwi r17, r11, CC_R17
1012 lwi r16, r11, CC_R16
1013 lwi r15, r11, CC_R15
1014 lwi r14, r11, CC_R14
1015 lwi r13, r11, CC_R13
1016 /* skip volatile registers */
1017 lwi r2, r11, CC_R2
1018 lwi r1, r11, CC_R1
1019
1020 /* special purpose registers */
1021 lwi r12, r11, CC_FSR
1022 mts rfsr, r12
1023 nop
1024 lwi r12, r11, CC_MSR
1025 mts rmsr, r12
1026 nop
1027
1028 rtsd r15, 8
1029 nop
1030
1031ENTRY(_reset)
1032 brai 0x70; /* Jump back to FS-boot */
1033
1034ENTRY(_break)
1035 mfs r5, rmsr
1036 nop
1037 swi r5, r0, 0x250 + TOPHYS(r0_ram)
1038 mfs r5, resr
1039 nop
1040 swi r5, r0, 0x254 + TOPHYS(r0_ram)
1041 bri 0
1042
1043 /* These are compiled and loaded into high memory, then
1044 * copied into place in mach_early_setup */
1045 .section .init.ivt, "ax"
1046 .org 0x0
1047 /* this is very important - here is the reset vector */
1048 /* in current MMU branch you don't care what is here - it is
1049 * used from bootloader site - but this is correct for FS-BOOT */
1050 brai 0x70
1051 nop
1052 brai TOPHYS(_user_exception); /* syscall handler */
1053 brai TOPHYS(_interrupt); /* Interrupt handler */
1054 brai TOPHYS(_break); /* nmi trap handler */
1055 brai TOPHYS(_hw_exception_handler); /* HW exception handler */
1056
1057 .org 0x60
1058 brai TOPHYS(_debug_exception); /* debug trap handler*/
1059
1060.section .rodata,"a"
1061#include "syscall_table.S"
1062
1063syscall_table_size=(.-sys_call_table)
1064
Steven J. Magnanice3266c2010-04-27 12:37:54 -05001065type_SYSCALL:
1066 .ascii "SYSCALL\0"
1067type_IRQ:
1068 .ascii "IRQ\0"
1069type_IRQ_PREEMPT:
1070 .ascii "IRQ (PREEMPTED)\0"
1071type_SYSCALL_PREEMPT:
1072 .ascii " SYSCALL (PREEMPTED)\0"
1073
1074 /*
1075 * Trap decoding for stack unwinder
1076 * Tuples are (start addr, end addr, string)
1077 * If return address lies on [start addr, end addr],
1078 * unwinder displays 'string'
1079 */
1080
1081 .align 4
1082.global microblaze_trap_handlers
1083microblaze_trap_handlers:
1084 /* Exact matches come first */
1085 .word ret_from_trap; .word ret_from_trap ; .word type_SYSCALL
1086 .word ret_from_irq ; .word ret_from_irq ; .word type_IRQ
1087 /* Fuzzy matches go here */
1088 .word ret_from_irq ; .word no_intr_resched ; .word type_IRQ_PREEMPT
1089 .word ret_from_trap; .word TRAP_return ; .word type_SYSCALL_PREEMPT
1090 /* End of table */
1091 .word 0 ; .word 0 ; .word 0