1 /* 1 /*
2 * linux/arch/nios2/kernel/entry.S !! 2 * PowerPC version
>> 3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
>> 4 * Rewritten by Cort Dougan (cort@fsmlabs.com) for PReP
>> 5 * Copyright (C) 1996 Cort Dougan <cort@fsmlabs.com>
>> 6 * Adapted for Power Macintosh by Paul Mackerras.
>> 7 * Low-level exception handlers and MMU support
>> 8 * rewritten by Paul Mackerras.
>> 9 * Copyright (C) 1996 Paul Mackerras.
>> 10 * MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
3 * 11 *
4 * Copyright (C) 2013-2014 Altera Corporation !! 12 * This file contains the system call entry code, context switch
5 * Copyright (C) 2009, Wind River Systems Inc !! 13 * code, and exception/interrupt return code for PowerPC.
6 * 14 *
7 * Implemented by fredrik.markstrom@gmail.com !! 15 * This program is free software; you can redistribute it and/or
>> 16 * modify it under the terms of the GNU General Public License
>> 17 * as published by the Free Software Foundation; either version
>> 18 * 2 of the License, or (at your option) any later version.
8 * 19 *
9 * Copyright (C) 1999-2002, Greg Ungerer (ger <<
10 * Copyright (C) 1998 D. Jeff Dionne <jeff@li <<
11 * Kenneth Albanowski <kja <<
12 * Copyright (C) 2000 Lineo Inc. (www.lineo. <<
13 * Copyright (C) 2004 Microtronix Datacom Lt <<
14 * <<
15 * This file is subject to the terms and condi <<
16 * License. See the file "COPYING" in the mai <<
17 * for more details. <<
18 * <<
19 * Linux/m68k support by Hamish Macdonald <<
20 * <<
21 * 68060 fixes by Jesper Skov <<
22 * ColdFire support by Greg Ungerer (gerg@snap <<
23 * 5307 fixes by David W. Miller <<
24 * linux 2.4 support David McCullough <davidm@s <<
25 */ 20 */
26 21
>> 22 #include <linux/config.h>
>> 23 #include <linux/errno.h>
27 #include <linux/sys.h> 24 #include <linux/sys.h>
28 #include <linux/linkage.h> !! 25 #include <linux/threads.h>
29 #include <asm/asm-offsets.h> <<
30 #include <asm/asm-macros.h> <<
31 #include <asm/thread_info.h> <<
32 #include <asm/errno.h> <<
33 #include <asm/setup.h> <<
34 #include <asm/entry.h> <<
35 #include <asm/unistd.h> <<
36 #include <asm/processor.h> 26 #include <asm/processor.h>
37 !! 27 #include <asm/page.h>
38 .macro GET_THREAD_INFO reg !! 28 #include <asm/mmu.h>
39 .if THREAD_SIZE & 0xffff0000 !! 29 #include <asm/cputable.h>
40 andhi \reg, sp, %hi(~(THREAD_SIZE-1) !! 30 #include <asm/ppc_asm.h>
41 .else !! 31 #include "ppc_defs.h"
42 addi \reg, r0, %lo(~(THREAD_SIZE-1) !! 32
43 and \reg, \reg, sp !! 33 #undef SHOW_SYSCALLS
44 .endif !! 34 #undef SHOW_SYSCALLS_TASK
45 .endm !! 35
46 !! 36 #ifdef SHOW_SYSCALLS_TASK
47 .macro kuser_cmpxchg_check !! 37 .data
48 /* !! 38 show_syscalls_task:
49 * Make sure our user space atomic hel !! 39 .long -1
50 * interrupted in a critical region. <<
51 * ea-4 = address of interrupted insn <<
52 * sp = saved regs. <<
53 * cmpxchg_ldw = first critical insn, <<
54 * If ea <= cmpxchg_stw and ea > cmpxc <<
55 * cmpxchg_ldw + 4. <<
56 */ <<
57 /* et = cmpxchg_stw + 4 */ <<
58 movui et, (KUSER_BASE + 4 + (cmpxchg <<
59 bgtu ea, et, 1f <<
60 <<
61 subi et, et, (cmpxchg_stw - cmpxchg <<
62 bltu ea, et, 1f <<
63 stw et, PT_EA(sp) /* fix up EA * <<
64 mov ea, et <<
65 1: <<
66 .endm <<
67 <<
68 .section .rodata <<
69 .align 4 <<
70 exception_table: <<
71 .word unhandled_exception /* 0 - <<
72 .word unhandled_exception /* 1 - <<
73 .word external_interrupt /* 2 - <<
74 .word handle_trap /* 3 - <<
75 <<
76 .word instruction_trap /* 4 - <<
77 .word handle_illegal /* 5 - <<
78 .word handle_unaligned /* 6 - <<
79 .word handle_unaligned /* 7 - <<
80 <<
81 .word handle_diverror /* 8 - <<
82 .word protection_exception_ba /* 9 - <<
83 .word protection_exception_instr /* 10 <<
84 .word protection_exception_ba /* 11 <<
85 <<
86 .word unhandled_exception /* 12 <<
87 .word protection_exception_pte /* 13 <<
88 .word protection_exception_pte /* 14 <<
89 .word protection_exception_pte /* 15 <<
90 <<
91 .word unhandled_exception /* 16 <<
92 <<
93 trap_table: <<
94 .word handle_system_call /* 0 <<
95 .word handle_trap_1 /* 1 <<
96 .word handle_trap_2 /* 2 <<
97 .word handle_trap_3 /* 3 <<
98 .word handle_trap_reserved /* 4 <<
99 .word handle_trap_reserved /* 5 <<
100 .word handle_trap_reserved /* 6 <<
101 .word handle_trap_reserved /* 7 <<
102 .word handle_trap_reserved /* 8 <<
103 .word handle_trap_reserved /* 9 <<
104 .word handle_trap_reserved /* 10 <<
105 .word handle_trap_reserved /* 11 <<
106 .word handle_trap_reserved /* 12 <<
107 .word handle_trap_reserved /* 13 <<
108 .word handle_trap_reserved /* 14 <<
109 .word handle_trap_reserved /* 15 <<
110 .word handle_trap_reserved /* 16 <<
111 .word handle_trap_reserved /* 17 <<
112 .word handle_trap_reserved /* 18 <<
113 .word handle_trap_reserved /* 19 <<
114 .word handle_trap_reserved /* 20 <<
115 .word handle_trap_reserved /* 21 <<
116 .word handle_trap_reserved /* 22 <<
117 .word handle_trap_reserved /* 23 <<
118 .word handle_trap_reserved /* 24 <<
119 .word handle_trap_reserved /* 25 <<
120 .word handle_trap_reserved /* 26 <<
121 .word handle_trap_reserved /* 27 <<
122 .word handle_trap_reserved /* 28 <<
123 .word handle_trap_reserved /* 29 <<
124 #ifdef CONFIG_KGDB <<
125 .word handle_kgdb_breakpoint /* 30 <<
126 #else <<
127 .word instruction_trap <<
128 #endif 40 #endif
129 .word handle_breakpoint /* 31 <<
130 <<
131 .text <<
132 .set noat <<
133 .set nobreak <<
134 <<
135 ENTRY(inthandler) <<
136 SAVE_ALL <<
137 41
138 kuser_cmpxchg_check !! 42 /*
139 !! 43 * Handle a system call.
140 /* Clear EH bit before we get a new ex <<
141 * and after we have saved it to the e <<
142 * whether it's trap, tlb-miss or inte <<
143 * estatus is not updated the next exc <<
144 */ <<
145 rdctl r24, status <<
146 movi r9, %lo(~STATUS_EH) <<
147 and r24, r24, r9 <<
148 wrctl status, r24 <<
149 <<
150 /* Read cause and vector and branch to <<
151 mov r4, sp <<
152 rdctl r5, exception <<
153 movia r9, exception_table <<
154 add r24, r9, r5 <<
155 ldw r24, 0(r24) <<
156 jmp r24 <<
157 <<
158 <<
159 /********************************************* <<
160 * Handle traps <<
161 ********************************************* <<
162 */ 44 */
163 ENTRY(handle_trap) !! 45 .text
164 ldwio r24, -4(ea) /* instruction !! 46 .stabs "arch/ppc/kernel/",N_SO,0,0,0f
165 srli r24, r24, 4 !! 47 .stabs "entry.S",N_SO,0,0,0f
166 andi r24, r24, 0x7c !! 48 0:
167 movia r9,trap_table !! 49
168 add r24, r24, r9 !! 50 _GLOBAL(DoSyscall)
169 ldw r24, 0(r24) !! 51 stw r0,THREAD+LAST_SYSCALL(r2)
170 jmp r24 !! 52 lwz r11,_CCR(r1) /* Clear SO bit in CR */
171 !! 53 lis r10,0x1000
>> 54 andc r11,r11,r10
>> 55 stw r11,_CCR(r1)
>> 56 #ifdef SHOW_SYSCALLS
>> 57 #ifdef SHOW_SYSCALLS_TASK
>> 58 lis r31,show_syscalls_task@ha
>> 59 lwz r31,show_syscalls_task@l(r31)
>> 60 cmp 0,r2,r31
>> 61 bne 1f
>> 62 #endif
>> 63 lis r3,7f@ha
>> 64 addi r3,r3,7f@l
>> 65 lwz r4,GPR0(r1)
>> 66 lwz r5,GPR3(r1)
>> 67 lwz r6,GPR4(r1)
>> 68 lwz r7,GPR5(r1)
>> 69 lwz r8,GPR6(r1)
>> 70 lwz r9,GPR7(r1)
>> 71 bl printk
>> 72 lis r3,77f@ha
>> 73 addi r3,r3,77f@l
>> 74 lwz r4,GPR8(r1)
>> 75 lwz r5,GPR9(r1)
>> 76 mr r6,r2
>> 77 bl printk
>> 78 lwz r0,GPR0(r1)
>> 79 lwz r3,GPR3(r1)
>> 80 lwz r4,GPR4(r1)
>> 81 lwz r5,GPR5(r1)
>> 82 lwz r6,GPR6(r1)
>> 83 lwz r7,GPR7(r1)
>> 84 lwz r8,GPR8(r1)
>> 85 1:
>> 86 #endif /* SHOW_SYSCALLS */
>> 87 cmpi 0,r0,0x7777 /* Special case for 'sys_sigreturn' */
>> 88 beq- 10f
>> 89 cmpi 0,r0,0x6666 /* Special case for 'sys_rt_sigreturn' */
>> 90 beq- 16f
>> 91 lwz r10,TASK_PTRACE(r2)
>> 92 andi. r10,r10,PT_TRACESYS
>> 93 bne- 50f
>> 94 cmpli 0,r0,NR_syscalls
>> 95 bge- 66f
>> 96 lis r10,sys_call_table@h
>> 97 ori r10,r10,sys_call_table@l
>> 98 slwi r0,r0,2
>> 99 lwzx r10,r10,r0 /* Fetch system call handler [ptr] */
>> 100 cmpi 0,r10,0
>> 101 beq- 66f
>> 102 mtlr r10
>> 103 addi r9,r1,STACK_FRAME_OVERHEAD
>> 104 blrl /* Call handler */
>> 105 .globl ret_from_syscall_1
>> 106 ret_from_syscall_1:
>> 107 20: stw r3,RESULT(r1) /* Save result */
>> 108 #ifdef SHOW_SYSCALLS
>> 109 #ifdef SHOW_SYSCALLS_TASK
>> 110 cmp 0,r2,r31
>> 111 bne 91f
>> 112 #endif
>> 113 mr r4,r3
>> 114 lis r3,79f@ha
>> 115 addi r3,r3,79f@l
>> 116 bl printk
>> 117 lwz r3,RESULT(r1)
>> 118 91:
>> 119 #endif
>> 120 li r10,-_LAST_ERRNO
>> 121 cmpl 0,r3,r10
>> 122 blt 30f
>> 123 neg r3,r3
>> 124 cmpi 0,r3,ERESTARTNOHAND
>> 125 bne 22f
>> 126 li r3,EINTR
>> 127 22: lwz r10,_CCR(r1) /* Set SO bit in CR */
>> 128 oris r10,r10,0x1000
>> 129 stw r10,_CCR(r1)
>> 130 30: stw r3,GPR3(r1) /* Update return value */
>> 131 b ret_from_except
>> 132 66: li r3,ENOSYS
>> 133 b 22b
>> 134 /* sys_sigreturn */
>> 135 10: addi r3,r1,STACK_FRAME_OVERHEAD
>> 136 bl sys_sigreturn
>> 137 cmpi 0,r3,0 /* Check for restarted system call */
>> 138 bge ret_from_except
>> 139 b 20b
>> 140 /* sys_rt_sigreturn */
>> 141 16: addi r3,r1,STACK_FRAME_OVERHEAD
>> 142 bl sys_rt_sigreturn
>> 143 cmpi 0,r3,0 /* Check for restarted system call */
>> 144 bge ret_from_except
>> 145 b 20b
>> 146 /* Traced system call support */
>> 147 50: bl syscall_trace
>> 148 lwz r0,GPR0(r1) /* Restore original registers */
>> 149 lwz r3,GPR3(r1)
>> 150 lwz r4,GPR4(r1)
>> 151 lwz r5,GPR5(r1)
>> 152 lwz r6,GPR6(r1)
>> 153 lwz r7,GPR7(r1)
>> 154 lwz r8,GPR8(r1)
>> 155 lwz r9,GPR9(r1)
>> 156 cmpli 0,r0,NR_syscalls
>> 157 bge- 66f
>> 158 lis r10,sys_call_table@h
>> 159 ori r10,r10,sys_call_table@l
>> 160 slwi r0,r0,2
>> 161 lwzx r10,r10,r0 /* Fetch system call handler [ptr] */
>> 162 cmpi 0,r10,0
>> 163 beq- 66f
>> 164 mtlr r10
>> 165 addi r9,r1,STACK_FRAME_OVERHEAD
>> 166 blrl /* Call handler */
>> 167 .globl ret_from_syscall_2
>> 168 ret_from_syscall_2:
>> 169 stw r3,RESULT(r1) /* Save result */
>> 170 li r10,-_LAST_ERRNO
>> 171 cmpl 0,r3,r10
>> 172 blt 60f
>> 173 neg r3,r3
>> 174 cmpi 0,r3,ERESTARTNOHAND
>> 175 bne 52f
>> 176 li r3,EINTR
>> 177 52: lwz r10,_CCR(r1) /* Set SO bit in CR */
>> 178 oris r10,r10,0x1000
>> 179 stw r10,_CCR(r1)
>> 180 60: stw r3,GPR3(r1) /* Update return value */
>> 181 bl syscall_trace
>> 182 b ret_from_except
>> 183 66: li r3,ENOSYS
>> 184 b 52b
>> 185 #ifdef SHOW_SYSCALLS
>> 186 7: .string "syscall %d(%x, %x, %x, %x, %x, "
>> 187 77: .string "%x, %x), current=%p\n"
>> 188 79: .string " -> %x\n"
>> 189 .align 2,0
>> 190 #endif
172 191
173 /********************************************* <<
174 * Handle system calls <<
175 ********************************************* <<
176 */ <<
177 ENTRY(handle_system_call) <<
178 /* Enable interrupts */ <<
179 rdctl r10, status <<
180 ori r10, r10, STATUS_PIE <<
181 wrctl status, r10 <<
182 <<
183 /* Reload registers destroyed by commo <<
184 ldw r4, PT_R4(sp) <<
185 ldw r5, PT_R5(sp) <<
186 <<
187 local_restart: <<
188 stw r2, PT_ORIG_R2(sp) <<
189 /* Check that the requested system cal <<
190 movui r1, __NR_syscalls <<
191 bgeu r2, r1, ret_invsyscall <<
192 slli r1, r2, 2 <<
193 movhi r11, %hiadj(sys_call_table) <<
194 add r1, r1, r11 <<
195 ldw r1, %lo(sys_call_table)(r1) <<
196 <<
197 /* Check if we are being traced */ <<
198 GET_THREAD_INFO r11 <<
199 ldw r11,TI_FLAGS(r11) <<
200 BTBNZ r11,r11,TIF_SYSCALL_TRACE,trac <<
201 <<
202 /* Execute the system call */ <<
203 callr r1 <<
204 <<
205 /* If the syscall returns a negative r <<
206 * Set r7 to 1 to indicate error, <<
207 * Negate r2 to get a positive error <<
208 * If the syscall returns zero or a po <<
209 * Set r7 to 0. <<
210 * The sigreturn system calls will ski <<
211 * adding to register ra. To avoid des <<
212 */ <<
213 translate_rc_and_ret: <<
214 movi r1, 0 <<
215 bge r2, zero, 3f <<
216 ldw r1, PT_ORIG_R2(sp) <<
217 addi r1, r1, 1 <<
218 beq r1, zero, 3f <<
219 sub r2, zero, r2 <<
220 movi r1, 1 <<
221 3: <<
222 stw r2, PT_R2(sp) <<
223 stw r1, PT_R7(sp) <<
224 end_translate_rc_and_ret: <<
225 <<
226 ret_from_exception: <<
227 ldw r1, PT_ESTATUS(sp) <<
228 /* if so, skip resched, signals */ <<
229 TSTBNZ r1, r1, ESTATUS_EU, Luser_retu <<
230 <<
231 restore_all: <<
232 rdctl r10, status <<
233 andi r10, r10, %lo(~STATUS_PIE) <<
234 wrctl status, r10 <<
235 RESTORE_ALL <<
236 eret <<
237 <<
238 /* If the syscall number was invalid r <<
239 ret_invsyscall: <<
240 movi r2, -ENOSYS <<
241 br translate_rc_and_ret <<
242 <<
243 /* This implements the same as above, <<
244 * do_syscall_trace_enter and do_sysca <<
245 * syscall in order for utilities like <<
246 */ <<
247 traced_system_call: <<
248 SAVE_SWITCH_STACK <<
249 call do_syscall_trace_enter <<
250 RESTORE_SWITCH_STACK <<
251 <<
252 /* Create system call register argumen <<
253 arguments on stack are already in p <<
254 of pt_regs. */ <<
255 ldw r2, PT_R2(sp) <<
256 ldw r4, PT_R4(sp) <<
257 ldw r5, PT_R5(sp) <<
258 ldw r6, PT_R6(sp) <<
259 ldw r7, PT_R7(sp) <<
260 <<
261 /* Fetch the syscall function. */ <<
262 movui r1, __NR_syscalls <<
263 bgeu r2, r1, traced_invsyscall <<
264 slli r1, r2, 2 <<
265 movhi r11,%hiadj(sys_call_table) <<
266 add r1, r1, r11 <<
267 ldw r1, %lo(sys_call_table)(r1) <<
268 <<
269 callr r1 <<
270 <<
271 /* If the syscall returns a negative r <<
272 * Set r7 to 1 to indicate error, <<
273 * Negate r2 to get a positive error <<
274 * If the syscall returns zero or a po <<
275 * Set r7 to 0. <<
276 * The sigreturn system calls will ski <<
277 * adding to register ra. To avoid des <<
278 */ <<
279 translate_rc_and_ret2: <<
280 movi r1, 0 <<
281 bge r2, zero, 4f <<
282 ldw r1, PT_ORIG_R2(sp) <<
283 addi r1, r1, 1 <<
284 beq r1, zero, 4f <<
285 sub r2, zero, r2 <<
286 movi r1, 1 <<
287 4: <<
288 stw r2, PT_R2(sp) <<
289 stw r1, PT_R7(sp) <<
290 end_translate_rc_and_ret2: <<
291 SAVE_SWITCH_STACK <<
292 call do_syscall_trace_exit <<
293 RESTORE_SWITCH_STACK <<
294 br ret_from_exception <<
295 <<
296 /* If the syscall number was invalid r <<
297 traced_invsyscall: <<
298 movi r2, -ENOSYS <<
299 br translate_rc_and_ret2 <<
300 <<
301 Luser_return: <<
302 GET_THREAD_INFO r11 <<
303 ldw r10, TI_FLAGS(r11) <<
304 ANDI32 r11, r10, _TIF_WORK_MASK <<
305 beq r11, r0, restore_all <<
306 BTBZ r1, r10, TIF_NEED_RESCHED, Lsi <<
307 <<
308 /* Reschedule work */ <<
309 call schedule <<
310 br ret_from_exception <<
311 <<
312 Lsignal_return: <<
313 ANDI32 r1, r10, _TIF_SIGPENDING | _TI <<
314 beq r1, r0, restore_all <<
315 mov r4, sp /* pt_ <<
316 SAVE_SWITCH_STACK <<
317 call do_notify_resume <<
318 beq r2, r0, no_work_pending <<
319 RESTORE_SWITCH_STACK <<
320 /* prepare restart syscall here withou <<
321 ldw r2, PT_R2(sp) /* reload sysc <<
322 ldw r4, PT_R4(sp) /* reload sysc <<
323 ldw r5, PT_R5(sp) <<
324 ldw r6, PT_R6(sp) <<
325 ldw r7, PT_R7(sp) <<
326 ldw r8, PT_R8(sp) <<
327 ldw r9, PT_R9(sp) <<
328 br local_restart /* restart sys <<
329 <<
330 no_work_pending: <<
331 RESTORE_SWITCH_STACK <<
332 br ret_from_exception <<
333 <<
334 /********************************************* <<
335 * Handle external interrupts. <<
336 ********************************************* <<
337 */ <<
338 /* 192 /*
339 * This is the generic interrupt handler (for !! 193 * This routine switches between two different tasks. The process
340 * sources). It figures out the vector number !! 194 * state of one is saved on its kernel stack. Then the state
341 * interrupt service routine directly. !! 195 * of the other is restored from its kernel stack. The memory
>> 196 * management hardware is updated to the second process's state.
>> 197 * Finally, we can return to the second process.
>> 198 * On entry, r3 points to the THREAD for the current task, r4
>> 199 * points to the THREAD for the new task.
>> 200 *
>> 201 * Note: there are two ways to get to the "going out" portion
>> 202 * of this code; either by coming in via the entry (_switch)
>> 203 * or via "fork" which must set up an environment equivalent
>> 204 * to the "_switch" path. If you change this , you'll have to
>> 205 * change the fork code also.
>> 206 *
>> 207 * The code which creates the new task context is in 'copy_thread'
>> 208 * in arch/ppc/kernel/process.c
342 */ 209 */
343 external_interrupt: !! 210 _GLOBAL(_switch)
344 rdctl r12, ipending !! 211 stwu r1,-INT_FRAME_SIZE(r1)
345 rdctl r9, ienable !! 212 stw r0,GPR0(r1)
346 and r12, r12, r9 !! 213 lwz r0,0(r1)
347 /* skip if no interrupt is pending */ !! 214 stw r0,GPR1(r1)
348 beq r12, r0, ret_from_interrupt !! 215 /* r3-r13 are caller saved -- Cort */
>> 216 SAVE_GPR(2, r1)
>> 217 SAVE_8GPRS(14, r1)
>> 218 SAVE_10GPRS(22, r1)
>> 219 mflr r20 /* Return to switch caller */
>> 220 stw r20,INT_FRAME_SIZE+4(r1)
>> 221 mfmsr r22
>> 222 li r0,MSR_FP /* Disable floating-point */
>> 223 #ifdef CONFIG_ALTIVEC
>> 224 BEGIN_FTR_SECTION
>> 225 oris r0,r0,MSR_VEC@h /* Disable altivec */
>> 226 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
>> 227 #endif /* CONFIG_ALTIVEC */
>> 228 and. r0,r0,r22 /* FP or altivec enabled? */
>> 229 beq+ 1f
>> 230 andc r22,r22,r0
>> 231 mtmsr r22
>> 232 isync
>> 233 1: stw r20,_NIP(r1)
>> 234 stw r22,_MSR(r1)
>> 235 stw r20,_LINK(r1)
>> 236 mfcr r20
>> 237 mfctr r22
>> 238 mfspr r23,XER
>> 239 stw r20,_CCR(r1)
>> 240 stw r22,_CTR(r1)
>> 241 stw r23,_XER(r1)
>> 242 li r0,0x0ff0
>> 243 stw r0,TRAP(r1)
>> 244 stw r1,KSP(r3) /* Set old stack pointer */
>> 245
>> 246 tophys(r0,r4)
>> 247 CLR_TOP32(r0)
>> 248 mtspr SPRG3,r0 /* Update current THREAD phys addr */
>> 249 lwz r1,KSP(r4) /* Load new stack pointer */
>> 250 /* save the old current 'last' for return value */
>> 251 mr r3,r2
>> 252 addi r2,r4,-THREAD /* Update current */
>> 253 lwz r0,_CCR(r1)
>> 254 mtcrf 0xFF,r0
>> 255 /* r3-r13 are destroyed -- Cort */
>> 256 REST_2GPRS(14, r1)
>> 257 REST_8GPRS(16, r1)
>> 258 REST_8GPRS(24, r1)
>> 259
>> 260 lwz r4,_NIP(r1) /* Return to _switch caller in new task */
>> 261 mtlr r4
>> 262 addi r1,r1,INT_FRAME_SIZE
>> 263 blr
>> 264
>> 265 .globl syscall_direct_return
>> 266 syscall_direct_return:
>> 267 addi r1,r3,-STACK_FRAME_OVERHEAD
>> 268 lwz r10,TASK_PTRACE(r2)
>> 269 andi. r10,r10,PT_TRACESYS
>> 270 beq+ ret_from_except
>> 271 bl syscall_trace
>> 272 b ret_from_except
>> 273
>> 274 .globl ret_from_fork
>> 275 ret_from_fork:
>> 276 bl schedule_tail
>> 277 lwz r0,TASK_PTRACE(r2)
>> 278 andi. r0,r0,PT_TRACESYS
>> 279 bnel- syscall_trace
>> 280 b ret_from_except
349 281
>> 282 .globl ret_from_intercept
>> 283 ret_from_intercept:
350 /* 284 /*
351 * Process an external hardware interr !! 285 * We may be returning from RTL and cannot do the normal checks
>> 286 * -- Cort
352 */ 287 */
>> 288 cmpi 0,r3,0
>> 289 beq restore
>> 290 .globl ret_from_except
>> 291 ret_from_except:
>> 292 lwz r3,_MSR(r1) /* Returning to user mode? */
>> 293 andi. r3,r3,MSR_PR
>> 294 beq+ do_signal_ret /* if so, check need_resched and signals */
>> 295 lwz r3,NEED_RESCHED(r2)
>> 296 cmpi 0,r3,0 /* check need_resched flag */
>> 297 beq+ 7f
>> 298 bl schedule
>> 299 7: lwz r5,SIGPENDING(r2) /* Check for pending unblocked signals */
>> 300 cmpwi 0,r5,0
>> 301 beq+ do_signal_ret
>> 302 li r3,0
>> 303 addi r4,r1,STACK_FRAME_OVERHEAD
>> 304 bl do_signal
>> 305 .globl do_signal_ret
>> 306 do_signal_ret:
>> 307 .globl ret_to_user_hook
>> 308 ret_to_user_hook:
>> 309 nop
>> 310 restore:
>> 311 lwz r3,_XER(r1)
>> 312 mtspr XER,r3
>> 313 REST_10GPRS(9,r1)
>> 314 REST_10GPRS(19,r1)
>> 315 REST_2GPRS(29,r1)
>> 316 REST_GPR(31,r1)
353 317
354 addi ea, ea, -4 /* re-issue th !! 318 /* make sure we hard disable here, even if rtl is active, to protect
355 stw ea, PT_EA(sp) !! 319 * SRR[01] and SPRG2 -- Cort
356 2: movi r4, %lo(-1) /* Start from !! 320 */
357 highes !! 321 mfmsr r0 /* Get current interrupt state */
358 /* This is the !! 322 rlwinm r0,r0,0,17,15 /* clear MSR_EE in r0 */
359 1: andi r10, r12, 1 /* Isolate bit !! 323 #ifdef CONFIG_4xx
360 srli r12, r12, 1 /* shift count !! 324 rlwinm r0,r0,0,23,21 /* clear MSR_DE in r0 */
361 multip <<
362 addi r4, r4, 1 <<
363 beq r10, r0, 1b <<
364 mov r5, sp /* Setup pt_re <<
365 call do_IRQ <<
366 rdctl r12, ipending /* check again <<
367 rdctl r9, ienable /* Isolate pos <<
368 and r12, r12, r9 <<
369 bne r12, r0, 2b <<
370 /* br ret_from_interrupt */ /* fall <<
371 <<
372 ENTRY(ret_from_interrupt) <<
373 ldw r1, PT_ESTATUS(sp) /* che <<
374 TSTBNZ r1, r1, ESTATUS_EU, Luser_retu <<
375 <<
376 #ifdef CONFIG_PREEMPTION <<
377 GET_THREAD_INFO r1 <<
378 ldw r4, TI_PREEMPT_COUNT(r1) <<
379 bne r4, r0, restore_all <<
380 ldw r4, TI_FLAGS(r1) <<
381 BTBZ r10, r4, TIF_NEED_RESCHED, res <<
382 ldw r4, PT_ESTATUS(sp) /* ? I <<
383 andi r10, r4, ESTATUS_EPIE <<
384 beq r10, r0, restore_all <<
385 call preempt_schedule_irq <<
386 #endif 325 #endif
387 br restore_all !! 326 SYNC /* Some chip revs have problems here... */
>> 327 mtmsr r0 /* Update machine state */
388 328
389 /********************************************* !! 329 PPC405_ERR77(0,r1)
390 * A few syscall wrappers !! 330 stwcx. r0,0,r1 /* to clear the reservation */
391 ********************************************* <<
392 */ <<
393 /* <<
394 * int clone(unsigned long clone_flags, unsign <<
395 * int __user * parent_tidptr, in <<
396 * int tls_val) <<
397 */ <<
398 ENTRY(sys_clone) <<
399 SAVE_SWITCH_STACK <<
400 subi sp, sp, 4 /* make space for tl <<
401 stw r8, 0(sp) /* pass tls pointer <<
402 call nios2_clone <<
403 addi sp, sp, 4 <<
404 RESTORE_SWITCH_STACK <<
405 ret <<
406 <<
407 ENTRY(sys_rt_sigreturn) <<
408 SAVE_SWITCH_STACK <<
409 mov r4, sp <<
410 call do_rt_sigreturn <<
411 RESTORE_SWITCH_STACK <<
412 addi ra, ra, (end_translate_rc_and_ <<
413 ret <<
414 <<
415 /********************************************* <<
416 * A few other wrappers and stubs <<
417 ********************************************* <<
418 */ <<
419 protection_exception_pte: <<
420 rdctl r6, pteaddr <<
421 slli r6, r6, 10 <<
422 call do_page_fault <<
423 br ret_from_exception <<
424 <<
425 protection_exception_ba: <<
426 rdctl r6, badaddr <<
427 call do_page_fault <<
428 br ret_from_exception <<
429 <<
430 protection_exception_instr: <<
431 call handle_supervisor_instr <<
432 br ret_from_exception <<
433 <<
434 handle_breakpoint: <<
435 call breakpoint_c <<
436 br ret_from_exception <<
437 <<
438 #ifdef CONFIG_NIOS2_ALIGNMENT_TRAP <<
439 handle_unaligned: <<
440 SAVE_SWITCH_STACK <<
441 call handle_unaligned_c <<
442 RESTORE_SWITCH_STACK <<
443 br ret_from_exception <<
444 #else <<
445 handle_unaligned: <<
446 call handle_unaligned_c <<
447 br ret_from_exception <<
448 #endif <<
449 331
450 handle_illegal: !! 332 /* if returning to user mode, set new sprg2 and save kernel SP */
451 call handle_illegal_c !! 333 lwz r0,_MSR(r1)
452 br ret_from_exception !! 334 andi. r0,r0,MSR_PR
453 !! 335 beq+ 1f
454 handle_diverror: !! 336 #ifdef CONFIG_ALTIVEC
455 call handle_diverror_c !! 337 BEGIN_FTR_SECTION
456 br ret_from_exception !! 338 lwz r0,THREAD+THREAD_VRSAVE(r2)
457 !! 339 mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */
458 #ifdef CONFIG_KGDB !! 340 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
459 handle_kgdb_breakpoint: !! 341 #endif /* CONFIG_ALTIVEC */
460 call kgdb_breakpoint_c !! 342 #if defined(CONFIG_4xx) && !defined(CONFIG_BDI_SWITCH)
461 br ret_from_exception !! 343 /* Restore the processor debugging state of the thread. Only do
>> 344 * this if we aren't using an Abatron BDI JTAG debugger. It doesn't
>> 345 * tolerate others mucking with the debug registers.
>> 346 */
>> 347 lwz r0,THREAD+THREAD_DBCR0(r2)
>> 348 mtspr SPRN_DBCR0,r0
462 #endif 349 #endif
>> 350 addi r0,r1,INT_FRAME_SIZE /* size of frame */
>> 351 stw r0,THREAD+KSP(r2) /* save kernel stack pointer */
>> 352 tophys(r8,r1)
>> 353 CLR_TOP32(r8)
>> 354 mtspr SPRG2,r8 /* phys exception stack pointer */
>> 355 1:
>> 356 lwz r3,_CTR(r1)
>> 357 lwz r0,_LINK(r1)
>> 358 mtctr r3
>> 359 mtlr r0
>> 360 REST_4GPRS(3, r1)
>> 361 REST_2GPRS(7, r1)
>> 362
>> 363 #ifndef CONFIG_SMP
>> 364 /* We have to "dummy" load from the context save area in case
>> 365 * these instructions cause an MMU fault. If this happens
>> 366 * after we load SRR0/SRR1, our return context is hosed. -- Dan
>> 367 *
>> 368 * This workaround is not enough, we must also make sure the
>> 369 * actual code for this routine is in the TLB or BAT mapped.
>> 370 * For 6xx/Power3, we know the code is in a BAT, so this should
>> 371 * be enough in UP. In SMP, I limit lowmem to the amount of
>> 372 * RAM that can be BAT mapped. Other CPUs may need additional
>> 373 * tweaks, especially if used SMP or if the code for this routine
>> 374 * crosses page boundaries. The TLB pin down for 4xx should help
>> 375 * for example. --BenH.
>> 376 */
>> 377 lwz r0,GPR0(r1)
>> 378 lwz r0,GPR2(r1)
>> 379 lwz r0,GPR1(r1)
>> 380 #endif /* ndef CONFIG_SMP */
>> 381
>> 382 /* We re-use r3,r4 here (the load above was to cause the MMU
>> 383 * fault if necessary). Using r3,r4 removes the need to "dummy"
>> 384 * load the CCR and NIP. Since we load them we may as well
>> 385 * use them.
>> 386 */
>> 387 lwz r3,_CCR(r1)
>> 388 lwz r4,_NIP(r1)
>> 389
>> 390 lwz r0,_MSR(r1)
>> 391 FIX_SRR1(r0,r2)
>> 392 mtspr SRR1,r0
>> 393 mtcrf 0xFF,r3
>> 394 mtspr SRR0,r4
>> 395 lwz r0,GPR0(r1)
>> 396 lwz r2,GPR2(r1)
>> 397 lwz r3,GPR3(r1)
>> 398 lwz r4,GPR4(r1)
>> 399 lwz r1,GPR1(r1)
>> 400 SYNC
>> 401 PPC405_ERR77_SYNC
>> 402 RFI
463 403
464 handle_trap_1: <<
465 call handle_trap_1_c <<
466 br ret_from_exception <<
467 <<
468 handle_trap_2: <<
469 call handle_trap_2_c <<
470 br ret_from_exception <<
471 <<
472 handle_trap_3: <<
473 handle_trap_reserved: <<
474 call handle_trap_3_c <<
475 br ret_from_exception <<
476 404
477 /* 405 /*
478 * Beware - when entering resume, prev (the cu !! 406 * PROM code for specific machines follows. Put it
479 * in r4, next (the new task) is in r5, don't !! 407 * here so it's easy to add arch-specific sections later.
480 * registers. !! 408 * -- Cort
481 */ 409 */
482 ENTRY(resume) !! 410 #if defined(CONFIG_ALL_PPC)
483 <<
484 rdctl r7, status <<
485 stw r7, TASK_THREAD + THREAD_KPSR( <<
486 <<
487 andi r7, r7, %lo(~STATUS_PIE) <<
488 wrctl status, r7 <<
489 <<
490 SAVE_SWITCH_STACK <<
491 stw sp, TASK_THREAD + THREAD_KSP(r <<
492 ldw sp, TASK_THREAD + THREAD_KSP(r <<
493 movia r24, _current_thread <<
494 GET_THREAD_INFO r1 <<
495 stw r1, 0(r24) <<
496 RESTORE_SWITCH_STACK <<
497 <<
498 ldw r7, TASK_THREAD + THREAD_KPSR( <<
499 wrctl status, r7 <<
500 ret <<
501 <<
502 ENTRY(ret_from_fork) <<
503 call schedule_tail <<
504 br ret_from_exception <<
505 <<
506 ENTRY(ret_from_kernel_thread) <<
507 call schedule_tail <<
508 mov r4,r17 /* arg */ <<
509 callr r16 /* function */ <<
510 br ret_from_exception <<
511 <<
512 /* 411 /*
513 * Kernel user helpers. !! 412 * On CHRP, the Run-Time Abstraction Services (RTAS) have to be
514 * !! 413 * called with the MMU off.
515 * Each segment is 64-byte aligned and will be <<
516 * New segments (if ever needed) must be added <<
517 * This mechanism should be used only for thin <<
518 * justified, and not be abused freely. <<
519 * <<
520 */ 414 */
521 !! 415 .globl enter_rtas
522 /* Filling pads with undefined instructions. !! 416 enter_rtas:
523 .macro kuser_pad sym size !! 417 mflr r0
524 .if ((. - \sym) & 3) !! 418 stw r0,20(r1)
525 .rept (4 - (. - \sym) & 3) !! 419 lis r4,rtas_data@ha
526 .byte 0 !! 420 lwz r4,rtas_data@l(r4)
527 .endr !! 421 lis r6,1f@ha /* physical return address for rtas */
528 .endif !! 422 addi r6,r6,1f@l
529 .rept ((\size - (. - \sym)) / 4) !! 423 addis r6,r6,-KERNELBASE@h
530 .word 0xdeadbeef !! 424 subi r7,r1,INT_FRAME_SIZE
531 .endr !! 425 addis r7,r7,-KERNELBASE@h
532 .endm !! 426 lis r8,rtas_entry@ha
533 !! 427 lwz r8,rtas_entry@l(r8)
534 .align 6 !! 428 mfmsr r9
535 .globl __kuser_helper_start !! 429 stw r9,8(r1)
536 __kuser_helper_start: !! 430 li r0,0
537 !! 431 ori r0,r0,MSR_EE|MSR_SE|MSR_BE|MSR_FE0|MSR_FE1
538 __kuser_helper_version: !! 432 andc r0,r9,r0
539 .word ((__kuser_helper_end - __kuser !! 433 li r10,MSR_IR|MSR_DR|MSR_FP
540 !! 434 andc r9,r0,r10
541 __kuser_cmpxchg: !! 435 SYNC /* disable interrupts so SRR0/1 */
542 /* !! 436 mtmsr r0 /* don't get trashed */
543 * r4 pointer to exchange variable !! 437 mtlr r6
544 * r5 old value !! 438 CLR_TOP32(r7)
545 * r6 new value !! 439 mtspr SPRG2,r7
546 */ !! 440 mtspr SRR0,r8
547 cmpxchg_ldw: !! 441 mtspr SRR1,r9
548 ldw r2, 0(r4) !! 442 RFI
549 sub r2, r2, r5 !! 443 1: addis r9,r1,-KERNELBASE@h
550 bne r2, zero, cmpxchg_ret !! 444 lwz r8,20(r9) /* get return address */
551 !! 445 lwz r9,8(r9) /* original msr value */
552 /* We had a match, store the new value !! 446 FIX_SRR1(r9,r0)
553 cmpxchg_stw: !! 447 li r0,0
554 stw r6, 0(r4) !! 448 mtspr SPRG2,r0
555 cmpxchg_ret: !! 449 mtspr SRR0,r8
556 ret !! 450 mtspr SRR1,r9
557 !! 451 RFI /* return to caller */
558 kuser_pad __kuser_cmpxchg, 64 !! 452 #endif /* CONFIG_ALL_PPC */
559 <<
560 .globl __kuser_sigtramp <<
561 __kuser_sigtramp: <<
562 movi r2, __NR_rt_sigreturn <<
563 trap <<
564 <<
565 kuser_pad __kuser_sigtramp, 64 <<
566 <<
567 .globl __kuser_helper_end <<
568 __kuser_helper_end: <<
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