1 /* 1 /*
2 * linux/arch/nios2/kernel/entry.S !! 2 * arch/alpha/kernel/entry.S
3 * 3 *
4 * Copyright (C) 2013-2014 Altera Corporation !! 4 * Kernel entry-points.
5 * Copyright (C) 2009, Wind River Systems Inc <<
6 * <<
7 * Implemented by fredrik.markstrom@gmail.com <<
8 * <<
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 */ 5 */
26 6
27 #include <linux/sys.h> <<
28 #include <linux/linkage.h> <<
29 #include <asm/asm-offsets.h> 7 #include <asm/asm-offsets.h>
30 #include <asm/asm-macros.h> <<
31 #include <asm/thread_info.h> 8 #include <asm/thread_info.h>
>> 9 #include <asm/pal.h>
32 #include <asm/errno.h> 10 #include <asm/errno.h>
33 #include <asm/setup.h> <<
34 #include <asm/entry.h> <<
35 #include <asm/unistd.h> 11 #include <asm/unistd.h>
36 #include <asm/processor.h> <<
37 12
38 .macro GET_THREAD_INFO reg !! 13 .text
39 .if THREAD_SIZE & 0xffff0000 !! 14 .set noat
40 andhi \reg, sp, %hi(~(THREAD_SIZE-1) !! 15 .cfi_sections .debug_frame
41 .else !! 16
42 addi \reg, r0, %lo(~(THREAD_SIZE-1) !! 17 /* Stack offsets. */
43 and \reg, \reg, sp !! 18 #define SP_OFF 184
44 .endif !! 19 #define SWITCH_STACK_SIZE 320
>> 20
>> 21 .macro CFI_START_OSF_FRAME func
>> 22 .align 4
>> 23 .globl \func
>> 24 .type \func,@function
>> 25 \func:
>> 26 .cfi_startproc simple
>> 27 .cfi_return_column 64
>> 28 .cfi_def_cfa $sp, 48
>> 29 .cfi_rel_offset 64, 8
>> 30 .cfi_rel_offset $gp, 16
>> 31 .cfi_rel_offset $16, 24
>> 32 .cfi_rel_offset $17, 32
>> 33 .cfi_rel_offset $18, 40
45 .endm 34 .endm
46 35
47 .macro kuser_cmpxchg_check !! 36 .macro CFI_END_OSF_FRAME func
48 /* !! 37 .cfi_endproc
49 * Make sure our user space atomic hel !! 38 .size \func, . - \func
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 39 .endm
67 40
68 .section .rodata !! 41 /*
69 .align 4 !! 42 * This defines the normal kernel pt-regs layout.
70 exception_table: !! 43 *
71 .word unhandled_exception /* 0 - !! 44 * regs 9-15 preserved by C code
72 .word unhandled_exception /* 1 - !! 45 * regs 16-18 saved by PAL-code
73 .word external_interrupt /* 2 - !! 46 * regs 29-30 saved and set up by PAL-code
74 .word handle_trap /* 3 - !! 47 * JRP - Save regs 16-18 in a special area of the stack, so that
75 !! 48 * the palcode-provided values are available to the signal handler.
76 .word instruction_trap /* 4 - !! 49 */
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 <<
129 .word handle_breakpoint /* 31 <<
130 50
131 .text !! 51 .macro SAVE_ALL
132 .set noat !! 52 subq $sp, SP_OFF, $sp
133 .set nobreak !! 53 .cfi_adjust_cfa_offset SP_OFF
>> 54 stq $0, 0($sp)
>> 55 stq $1, 8($sp)
>> 56 stq $2, 16($sp)
>> 57 stq $3, 24($sp)
>> 58 stq $4, 32($sp)
>> 59 stq $28, 144($sp)
>> 60 .cfi_rel_offset $0, 0
>> 61 .cfi_rel_offset $1, 8
>> 62 .cfi_rel_offset $2, 16
>> 63 .cfi_rel_offset $3, 24
>> 64 .cfi_rel_offset $4, 32
>> 65 .cfi_rel_offset $28, 144
>> 66 lda $2, alpha_mv
>> 67 stq $5, 40($sp)
>> 68 stq $6, 48($sp)
>> 69 stq $7, 56($sp)
>> 70 stq $8, 64($sp)
>> 71 stq $19, 72($sp)
>> 72 stq $20, 80($sp)
>> 73 stq $21, 88($sp)
>> 74 ldq $2, HAE_CACHE($2)
>> 75 stq $22, 96($sp)
>> 76 stq $23, 104($sp)
>> 77 stq $24, 112($sp)
>> 78 stq $25, 120($sp)
>> 79 stq $26, 128($sp)
>> 80 stq $27, 136($sp)
>> 81 stq $2, 152($sp)
>> 82 stq $16, 160($sp)
>> 83 stq $17, 168($sp)
>> 84 stq $18, 176($sp)
>> 85 .cfi_rel_offset $5, 40
>> 86 .cfi_rel_offset $6, 48
>> 87 .cfi_rel_offset $7, 56
>> 88 .cfi_rel_offset $8, 64
>> 89 .cfi_rel_offset $19, 72
>> 90 .cfi_rel_offset $20, 80
>> 91 .cfi_rel_offset $21, 88
>> 92 .cfi_rel_offset $22, 96
>> 93 .cfi_rel_offset $23, 104
>> 94 .cfi_rel_offset $24, 112
>> 95 .cfi_rel_offset $25, 120
>> 96 .cfi_rel_offset $26, 128
>> 97 .cfi_rel_offset $27, 136
>> 98 .endm
134 99
135 ENTRY(inthandler) !! 100 .macro RESTORE_ALL
>> 101 lda $19, alpha_mv
>> 102 ldq $0, 0($sp)
>> 103 ldq $1, 8($sp)
>> 104 ldq $2, 16($sp)
>> 105 ldq $3, 24($sp)
>> 106 ldq $21, 152($sp)
>> 107 ldq $20, HAE_CACHE($19)
>> 108 ldq $4, 32($sp)
>> 109 ldq $5, 40($sp)
>> 110 ldq $6, 48($sp)
>> 111 ldq $7, 56($sp)
>> 112 subq $20, $21, $20
>> 113 ldq $8, 64($sp)
>> 114 beq $20, 99f
>> 115 ldq $20, HAE_REG($19)
>> 116 stq $21, HAE_CACHE($19)
>> 117 stq $21, 0($20)
>> 118 99: ldq $19, 72($sp)
>> 119 ldq $20, 80($sp)
>> 120 ldq $21, 88($sp)
>> 121 ldq $22, 96($sp)
>> 122 ldq $23, 104($sp)
>> 123 ldq $24, 112($sp)
>> 124 ldq $25, 120($sp)
>> 125 ldq $26, 128($sp)
>> 126 ldq $27, 136($sp)
>> 127 ldq $28, 144($sp)
>> 128 addq $sp, SP_OFF, $sp
>> 129 .cfi_restore $0
>> 130 .cfi_restore $1
>> 131 .cfi_restore $2
>> 132 .cfi_restore $3
>> 133 .cfi_restore $4
>> 134 .cfi_restore $5
>> 135 .cfi_restore $6
>> 136 .cfi_restore $7
>> 137 .cfi_restore $8
>> 138 .cfi_restore $19
>> 139 .cfi_restore $20
>> 140 .cfi_restore $21
>> 141 .cfi_restore $22
>> 142 .cfi_restore $23
>> 143 .cfi_restore $24
>> 144 .cfi_restore $25
>> 145 .cfi_restore $26
>> 146 .cfi_restore $27
>> 147 .cfi_restore $28
>> 148 .cfi_adjust_cfa_offset -SP_OFF
>> 149 .endm
>> 150
>> 151 .macro DO_SWITCH_STACK
>> 152 bsr $1, do_switch_stack
>> 153 .cfi_adjust_cfa_offset SWITCH_STACK_SIZE
>> 154 .cfi_rel_offset $9, 0
>> 155 .cfi_rel_offset $10, 8
>> 156 .cfi_rel_offset $11, 16
>> 157 .cfi_rel_offset $12, 24
>> 158 .cfi_rel_offset $13, 32
>> 159 .cfi_rel_offset $14, 40
>> 160 .cfi_rel_offset $15, 48
>> 161 /* We don't really care about the FP registers for debugging. */
>> 162 .endm
>> 163
>> 164 .macro UNDO_SWITCH_STACK
>> 165 bsr $1, undo_switch_stack
>> 166 .cfi_restore $9
>> 167 .cfi_restore $10
>> 168 .cfi_restore $11
>> 169 .cfi_restore $12
>> 170 .cfi_restore $13
>> 171 .cfi_restore $14
>> 172 .cfi_restore $15
>> 173 .cfi_adjust_cfa_offset -SWITCH_STACK_SIZE
>> 174 .endm
>> 175
>> 176 /*
>> 177 * Non-syscall kernel entry points.
>> 178 */
>> 179
>> 180 CFI_START_OSF_FRAME entInt
136 SAVE_ALL 181 SAVE_ALL
>> 182 lda $8, 0x3fff
>> 183 lda $26, ret_from_sys_call
>> 184 bic $sp, $8, $8
>> 185 mov $sp, $19
>> 186 jsr $31, do_entInt
>> 187 CFI_END_OSF_FRAME entInt
137 188
138 kuser_cmpxchg_check !! 189 CFI_START_OSF_FRAME entArith
>> 190 SAVE_ALL
>> 191 lda $8, 0x3fff
>> 192 lda $26, ret_from_sys_call
>> 193 bic $sp, $8, $8
>> 194 mov $sp, $18
>> 195 jsr $31, do_entArith
>> 196 CFI_END_OSF_FRAME entArith
139 197
140 /* Clear EH bit before we get a new ex !! 198 CFI_START_OSF_FRAME entMM
141 * and after we have saved it to the e !! 199 SAVE_ALL
142 * whether it's trap, tlb-miss or inte !! 200 /* save $9 - $15 so the inline exception code can manipulate them. */
143 * estatus is not updated the next exc !! 201 subq $sp, 56, $sp
144 */ !! 202 .cfi_adjust_cfa_offset 56
145 rdctl r24, status !! 203 stq $9, 0($sp)
146 movi r9, %lo(~STATUS_EH) !! 204 stq $10, 8($sp)
147 and r24, r24, r9 !! 205 stq $11, 16($sp)
148 wrctl status, r24 !! 206 stq $12, 24($sp)
149 !! 207 stq $13, 32($sp)
150 /* Read cause and vector and branch to !! 208 stq $14, 40($sp)
151 mov r4, sp !! 209 stq $15, 48($sp)
152 rdctl r5, exception !! 210 .cfi_rel_offset $9, 0
153 movia r9, exception_table !! 211 .cfi_rel_offset $10, 8
154 add r24, r9, r5 !! 212 .cfi_rel_offset $11, 16
155 ldw r24, 0(r24) !! 213 .cfi_rel_offset $12, 24
156 jmp r24 !! 214 .cfi_rel_offset $13, 32
157 !! 215 .cfi_rel_offset $14, 40
158 !! 216 .cfi_rel_offset $15, 48
159 /********************************************* !! 217 addq $sp, 56, $19
160 * Handle traps !! 218 /* handle the fault */
161 ********************************************* !! 219 lda $8, 0x3fff
162 */ !! 220 bic $sp, $8, $8
163 ENTRY(handle_trap) !! 221 jsr $26, do_page_fault
164 ldwio r24, -4(ea) /* instruction !! 222 /* reload the registers after the exception code played. */
165 srli r24, r24, 4 !! 223 ldq $9, 0($sp)
166 andi r24, r24, 0x7c !! 224 ldq $10, 8($sp)
167 movia r9,trap_table !! 225 ldq $11, 16($sp)
168 add r24, r24, r9 !! 226 ldq $12, 24($sp)
169 ldw r24, 0(r24) !! 227 ldq $13, 32($sp)
170 jmp r24 !! 228 ldq $14, 40($sp)
171 !! 229 ldq $15, 48($sp)
172 !! 230 addq $sp, 56, $sp
173 /********************************************* !! 231 .cfi_restore $9
174 * Handle system calls !! 232 .cfi_restore $10
175 ********************************************* !! 233 .cfi_restore $11
176 */ !! 234 .cfi_restore $12
177 ENTRY(handle_system_call) !! 235 .cfi_restore $13
178 /* Enable interrupts */ !! 236 .cfi_restore $14
179 rdctl r10, status !! 237 .cfi_restore $15
180 ori r10, r10, STATUS_PIE !! 238 .cfi_adjust_cfa_offset -56
181 wrctl status, r10 !! 239 /* finish up the syscall as normal. */
182 !! 240 br ret_from_sys_call
183 /* Reload registers destroyed by commo !! 241 CFI_END_OSF_FRAME entMM
184 ldw r4, PT_R4(sp) !! 242
185 ldw r5, PT_R5(sp) !! 243 CFI_START_OSF_FRAME entIF
186 !! 244 SAVE_ALL
187 local_restart: !! 245 lda $8, 0x3fff
188 stw r2, PT_ORIG_R2(sp) !! 246 lda $26, ret_from_sys_call
189 /* Check that the requested system cal !! 247 bic $sp, $8, $8
190 movui r1, __NR_syscalls !! 248 mov $sp, $17
191 bgeu r2, r1, ret_invsyscall !! 249 jsr $31, do_entIF
192 slli r1, r2, 2 !! 250 CFI_END_OSF_FRAME entIF
193 movhi r11, %hiadj(sys_call_table) !! 251
194 add r1, r1, r11 !! 252 CFI_START_OSF_FRAME entUna
195 ldw r1, %lo(sys_call_table)(r1) !! 253 lda $sp, -256($sp)
196 !! 254 .cfi_adjust_cfa_offset 256
197 /* Check if we are being traced */ !! 255 stq $0, 0($sp)
198 GET_THREAD_INFO r11 !! 256 .cfi_rel_offset $0, 0
199 ldw r11,TI_FLAGS(r11) !! 257 .cfi_remember_state
200 BTBNZ r11,r11,TIF_SYSCALL_TRACE,trac !! 258 ldq $0, 256($sp) /* get PS */
201 !! 259 stq $1, 8($sp)
202 /* Execute the system call */ !! 260 stq $2, 16($sp)
203 callr r1 !! 261 stq $3, 24($sp)
204 !! 262 and $0, 8, $0 /* user mode? */
205 /* If the syscall returns a negative r !! 263 stq $4, 32($sp)
206 * Set r7 to 1 to indicate error, !! 264 bne $0, entUnaUser /* yup -> do user-level unaligned fault */
207 * Negate r2 to get a positive error !! 265 stq $5, 40($sp)
208 * If the syscall returns zero or a po !! 266 stq $6, 48($sp)
209 * Set r7 to 0. !! 267 stq $7, 56($sp)
210 * The sigreturn system calls will ski !! 268 stq $8, 64($sp)
211 * adding to register ra. To avoid des !! 269 stq $9, 72($sp)
212 */ !! 270 stq $10, 80($sp)
213 translate_rc_and_ret: !! 271 stq $11, 88($sp)
214 movi r1, 0 !! 272 stq $12, 96($sp)
215 bge r2, zero, 3f !! 273 stq $13, 104($sp)
216 ldw r1, PT_ORIG_R2(sp) !! 274 stq $14, 112($sp)
217 addi r1, r1, 1 !! 275 stq $15, 120($sp)
218 beq r1, zero, 3f !! 276 /* 16-18 PAL-saved */
219 sub r2, zero, r2 !! 277 stq $19, 152($sp)
220 movi r1, 1 !! 278 stq $20, 160($sp)
221 3: !! 279 stq $21, 168($sp)
222 stw r2, PT_R2(sp) !! 280 stq $22, 176($sp)
223 stw r1, PT_R7(sp) !! 281 stq $23, 184($sp)
224 end_translate_rc_and_ret: !! 282 stq $24, 192($sp)
225 !! 283 stq $25, 200($sp)
226 ret_from_exception: !! 284 stq $26, 208($sp)
227 ldw r1, PT_ESTATUS(sp) !! 285 stq $27, 216($sp)
228 /* if so, skip resched, signals */ !! 286 stq $28, 224($sp)
229 TSTBNZ r1, r1, ESTATUS_EU, Luser_retu !! 287 mov $sp, $19
>> 288 stq $gp, 232($sp)
>> 289 .cfi_rel_offset $1, 1*8
>> 290 .cfi_rel_offset $2, 2*8
>> 291 .cfi_rel_offset $3, 3*8
>> 292 .cfi_rel_offset $4, 4*8
>> 293 .cfi_rel_offset $5, 5*8
>> 294 .cfi_rel_offset $6, 6*8
>> 295 .cfi_rel_offset $7, 7*8
>> 296 .cfi_rel_offset $8, 8*8
>> 297 .cfi_rel_offset $9, 9*8
>> 298 .cfi_rel_offset $10, 10*8
>> 299 .cfi_rel_offset $11, 11*8
>> 300 .cfi_rel_offset $12, 12*8
>> 301 .cfi_rel_offset $13, 13*8
>> 302 .cfi_rel_offset $14, 14*8
>> 303 .cfi_rel_offset $15, 15*8
>> 304 .cfi_rel_offset $19, 19*8
>> 305 .cfi_rel_offset $20, 20*8
>> 306 .cfi_rel_offset $21, 21*8
>> 307 .cfi_rel_offset $22, 22*8
>> 308 .cfi_rel_offset $23, 23*8
>> 309 .cfi_rel_offset $24, 24*8
>> 310 .cfi_rel_offset $25, 25*8
>> 311 .cfi_rel_offset $26, 26*8
>> 312 .cfi_rel_offset $27, 27*8
>> 313 .cfi_rel_offset $28, 28*8
>> 314 .cfi_rel_offset $29, 29*8
>> 315 lda $8, 0x3fff
>> 316 stq $31, 248($sp)
>> 317 bic $sp, $8, $8
>> 318 jsr $26, do_entUna
>> 319 ldq $0, 0($sp)
>> 320 ldq $1, 8($sp)
>> 321 ldq $2, 16($sp)
>> 322 ldq $3, 24($sp)
>> 323 ldq $4, 32($sp)
>> 324 ldq $5, 40($sp)
>> 325 ldq $6, 48($sp)
>> 326 ldq $7, 56($sp)
>> 327 ldq $8, 64($sp)
>> 328 ldq $9, 72($sp)
>> 329 ldq $10, 80($sp)
>> 330 ldq $11, 88($sp)
>> 331 ldq $12, 96($sp)
>> 332 ldq $13, 104($sp)
>> 333 ldq $14, 112($sp)
>> 334 ldq $15, 120($sp)
>> 335 /* 16-18 PAL-saved */
>> 336 ldq $19, 152($sp)
>> 337 ldq $20, 160($sp)
>> 338 ldq $21, 168($sp)
>> 339 ldq $22, 176($sp)
>> 340 ldq $23, 184($sp)
>> 341 ldq $24, 192($sp)
>> 342 ldq $25, 200($sp)
>> 343 ldq $26, 208($sp)
>> 344 ldq $27, 216($sp)
>> 345 ldq $28, 224($sp)
>> 346 ldq $gp, 232($sp)
>> 347 lda $sp, 256($sp)
>> 348 .cfi_restore $1
>> 349 .cfi_restore $2
>> 350 .cfi_restore $3
>> 351 .cfi_restore $4
>> 352 .cfi_restore $5
>> 353 .cfi_restore $6
>> 354 .cfi_restore $7
>> 355 .cfi_restore $8
>> 356 .cfi_restore $9
>> 357 .cfi_restore $10
>> 358 .cfi_restore $11
>> 359 .cfi_restore $12
>> 360 .cfi_restore $13
>> 361 .cfi_restore $14
>> 362 .cfi_restore $15
>> 363 .cfi_restore $19
>> 364 .cfi_restore $20
>> 365 .cfi_restore $21
>> 366 .cfi_restore $22
>> 367 .cfi_restore $23
>> 368 .cfi_restore $24
>> 369 .cfi_restore $25
>> 370 .cfi_restore $26
>> 371 .cfi_restore $27
>> 372 .cfi_restore $28
>> 373 .cfi_restore $29
>> 374 .cfi_adjust_cfa_offset -256
>> 375 call_pal PAL_rti
>> 376
>> 377 .align 4
>> 378 entUnaUser:
>> 379 .cfi_restore_state
>> 380 ldq $0, 0($sp) /* restore original $0 */
>> 381 lda $sp, 256($sp) /* pop entUna's stack frame */
>> 382 .cfi_restore $0
>> 383 .cfi_adjust_cfa_offset -256
>> 384 SAVE_ALL /* setup normal kernel stack */
>> 385 lda $sp, -56($sp)
>> 386 .cfi_adjust_cfa_offset 56
>> 387 stq $9, 0($sp)
>> 388 stq $10, 8($sp)
>> 389 stq $11, 16($sp)
>> 390 stq $12, 24($sp)
>> 391 stq $13, 32($sp)
>> 392 stq $14, 40($sp)
>> 393 stq $15, 48($sp)
>> 394 .cfi_rel_offset $9, 0
>> 395 .cfi_rel_offset $10, 8
>> 396 .cfi_rel_offset $11, 16
>> 397 .cfi_rel_offset $12, 24
>> 398 .cfi_rel_offset $13, 32
>> 399 .cfi_rel_offset $14, 40
>> 400 .cfi_rel_offset $15, 48
>> 401 lda $8, 0x3fff
>> 402 addq $sp, 56, $19
>> 403 bic $sp, $8, $8
>> 404 jsr $26, do_entUnaUser
>> 405 ldq $9, 0($sp)
>> 406 ldq $10, 8($sp)
>> 407 ldq $11, 16($sp)
>> 408 ldq $12, 24($sp)
>> 409 ldq $13, 32($sp)
>> 410 ldq $14, 40($sp)
>> 411 ldq $15, 48($sp)
>> 412 lda $sp, 56($sp)
>> 413 .cfi_restore $9
>> 414 .cfi_restore $10
>> 415 .cfi_restore $11
>> 416 .cfi_restore $12
>> 417 .cfi_restore $13
>> 418 .cfi_restore $14
>> 419 .cfi_restore $15
>> 420 .cfi_adjust_cfa_offset -56
>> 421 br ret_from_sys_call
>> 422 CFI_END_OSF_FRAME entUna
>> 423
>> 424 CFI_START_OSF_FRAME entDbg
>> 425 SAVE_ALL
>> 426 lda $8, 0x3fff
>> 427 lda $26, ret_from_sys_call
>> 428 bic $sp, $8, $8
>> 429 mov $sp, $16
>> 430 jsr $31, do_entDbg
>> 431 CFI_END_OSF_FRAME entDbg
>> 432
>> 433 /*
>> 434 * The system call entry point is special. Most importantly, it looks
>> 435 * like a function call to userspace as far as clobbered registers. We
>> 436 * do preserve the argument registers (for syscall restarts) and $26
>> 437 * (for leaf syscall functions).
>> 438 *
>> 439 * So much for theory. We don't take advantage of this yet.
>> 440 *
>> 441 * Note that a0-a2 are not saved by PALcode as with the other entry points.
>> 442 */
230 443
>> 444 .align 4
>> 445 .globl entSys
>> 446 .type entSys, @function
>> 447 .cfi_startproc simple
>> 448 .cfi_return_column 64
>> 449 .cfi_def_cfa $sp, 48
>> 450 .cfi_rel_offset 64, 8
>> 451 .cfi_rel_offset $gp, 16
>> 452 entSys:
>> 453 SAVE_ALL
>> 454 lda $8, 0x3fff
>> 455 bic $sp, $8, $8
>> 456 lda $4, NR_SYSCALLS($31)
>> 457 stq $16, SP_OFF+24($sp)
>> 458 lda $5, sys_call_table
>> 459 lda $27, sys_ni_syscall
>> 460 cmpult $0, $4, $4
>> 461 ldl $3, TI_FLAGS($8)
>> 462 stq $17, SP_OFF+32($sp)
>> 463 s8addq $0, $5, $5
>> 464 stq $18, SP_OFF+40($sp)
>> 465 .cfi_rel_offset $16, SP_OFF+24
>> 466 .cfi_rel_offset $17, SP_OFF+32
>> 467 .cfi_rel_offset $18, SP_OFF+40
>> 468 #ifdef CONFIG_AUDITSYSCALL
>> 469 lda $6, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
>> 470 and $3, $6, $3
>> 471 bne $3, strace
>> 472 #else
>> 473 blbs $3, strace /* check for SYSCALL_TRACE in disguise */
>> 474 #endif
>> 475 beq $4, 1f
>> 476 ldq $27, 0($5)
>> 477 1: jsr $26, ($27), alpha_ni_syscall
>> 478 ldgp $gp, 0($26)
>> 479 blt $0, $syscall_error /* the call failed */
>> 480 stq $0, 0($sp)
>> 481 stq $31, 72($sp) /* a3=0 => no error */
>> 482
>> 483 .align 4
>> 484 .globl ret_from_sys_call
>> 485 ret_from_sys_call:
>> 486 cmovne $26, 0, $18 /* $18 = 0 => non-restartable */
>> 487 ldq $0, SP_OFF($sp)
>> 488 and $0, 8, $0
>> 489 beq $0, ret_to_kernel
>> 490 ret_to_user:
>> 491 /* Make sure need_resched and sigpending don't change between
>> 492 sampling and the rti. */
>> 493 lda $16, 7
>> 494 call_pal PAL_swpipl
>> 495 ldl $17, TI_FLAGS($8)
>> 496 and $17, _TIF_WORK_MASK, $2
>> 497 bne $2, work_pending
231 restore_all: 498 restore_all:
232 rdctl r10, status !! 499 .cfi_remember_state
233 andi r10, r10, %lo(~STATUS_PIE) <<
234 wrctl status, r10 <<
235 RESTORE_ALL 500 RESTORE_ALL
236 eret !! 501 call_pal PAL_rti
237 502
238 /* If the syscall number was invalid r !! 503 ret_to_kernel:
239 ret_invsyscall: !! 504 .cfi_restore_state
240 movi r2, -ENOSYS !! 505 lda $16, 7
241 br translate_rc_and_ret !! 506 call_pal PAL_swpipl
242 !! 507 br restore_all
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 /* <<
339 * This is the generic interrupt handler (for <<
340 * sources). It figures out the vector number <<
341 * interrupt service routine directly. <<
342 */ <<
343 external_interrupt: <<
344 rdctl r12, ipending <<
345 rdctl r9, ienable <<
346 and r12, r12, r9 <<
347 /* skip if no interrupt is pending */ <<
348 beq r12, r0, ret_from_interrupt <<
349 508
>> 509 .align 3
>> 510 $syscall_error:
350 /* 511 /*
351 * Process an external hardware interr !! 512 * Some system calls (e.g., ptrace) can return arbitrary
>> 513 * values which might normally be mistaken as error numbers.
>> 514 * Those functions must zero $0 (v0) directly in the stack
>> 515 * frame to indicate that a negative return value wasn't an
>> 516 * error number..
352 */ 517 */
>> 518 ldq $18, 0($sp) /* old syscall nr (zero if success) */
>> 519 beq $18, $ret_success
353 520
354 addi ea, ea, -4 /* re-issue th !! 521 ldq $19, 72($sp) /* .. and this a3 */
355 stw ea, PT_EA(sp) !! 522 subq $31, $0, $0 /* with error in v0 */
356 2: movi r4, %lo(-1) /* Start from !! 523 addq $31, 1, $1 /* set a3 for errno return */
357 highes !! 524 stq $0, 0($sp)
358 /* This is the !! 525 mov $31, $26 /* tell "ret_from_sys_call" we can restart */
359 1: andi r10, r12, 1 /* Isolate bit !! 526 stq $1, 72($sp) /* a3 for return */
360 srli r12, r12, 1 /* shift count !! 527 br ret_from_sys_call
361 multip !! 528
362 addi r4, r4, 1 !! 529 $ret_success:
363 beq r10, r0, 1b !! 530 stq $0, 0($sp)
364 mov r5, sp /* Setup pt_re !! 531 stq $31, 72($sp) /* a3=0 => no error */
365 call do_IRQ !! 532 br ret_from_sys_call
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 <<
387 br restore_all <<
388 533
389 /********************************************* <<
390 * A few syscall wrappers <<
391 ********************************************* <<
392 */ <<
393 /* 534 /*
394 * int clone(unsigned long clone_flags, unsign !! 535 * Do all cleanup when returning from all interrupts and system calls.
395 * int __user * parent_tidptr, in !! 536 *
396 * int tls_val) !! 537 * Arguments:
397 */ !! 538 * $8: current.
398 ENTRY(sys_clone) !! 539 * $17: TI_FLAGS.
399 SAVE_SWITCH_STACK !! 540 * $18: The old syscall number, or zero if this is not a return
400 subi sp, sp, 4 /* make space for tl !! 541 * from a syscall that errored and is possibly restartable.
401 stw r8, 0(sp) /* pass tls pointer !! 542 * $19: The old a3 value
402 call nios2_clone !! 543 */
403 addi sp, sp, 4 <<
404 RESTORE_SWITCH_STACK <<
405 ret <<
406 544
407 ENTRY(sys_rt_sigreturn) !! 545 .align 4
408 SAVE_SWITCH_STACK !! 546 .type work_pending, @function
409 mov r4, sp !! 547 work_pending:
410 call do_rt_sigreturn !! 548 and $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING, $2
411 RESTORE_SWITCH_STACK !! 549 bne $2, $work_notifysig
412 addi ra, ra, (end_translate_rc_and_ <<
413 ret <<
414 550
415 /********************************************* !! 551 $work_resched:
416 * A few other wrappers and stubs !! 552 /*
417 ********************************************* !! 553 * We can get here only if we returned from syscall without SIGPENDING
418 */ !! 554 * or got through work_notifysig already. Either case means no syscall
419 protection_exception_pte: !! 555 * restarts for us, so let $18 and $19 burn.
420 rdctl r6, pteaddr !! 556 */
421 slli r6, r6, 10 !! 557 jsr $26, schedule
422 call do_page_fault !! 558 mov 0, $18
423 br ret_from_exception !! 559 br ret_to_user
424 !! 560
425 protection_exception_ba: !! 561 $work_notifysig:
426 rdctl r6, badaddr !! 562 mov $sp, $16
427 call do_page_fault !! 563 DO_SWITCH_STACK
428 br ret_from_exception !! 564 jsr $26, do_work_pending
429 !! 565 UNDO_SWITCH_STACK
430 protection_exception_instr: !! 566 br restore_all
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 <<
449 567
450 handle_illegal: !! 568 /*
451 call handle_illegal_c !! 569 * PTRACE syscall handler
452 br ret_from_exception !! 570 */
453 <<
454 handle_diverror: <<
455 call handle_diverror_c <<
456 br ret_from_exception <<
457 <<
458 #ifdef CONFIG_KGDB <<
459 handle_kgdb_breakpoint: <<
460 call kgdb_breakpoint_c <<
461 br ret_from_exception <<
462 #endif <<
463 571
464 handle_trap_1: !! 572 .align 4
465 call handle_trap_1_c !! 573 .type strace, @function
466 br ret_from_exception !! 574 strace:
467 !! 575 /* set up signal stack, call syscall_trace */
468 handle_trap_2: !! 576 DO_SWITCH_STACK
469 call handle_trap_2_c !! 577 jsr $26, syscall_trace_enter /* returns the syscall number */
470 br ret_from_exception !! 578 UNDO_SWITCH_STACK
471 !! 579
472 handle_trap_3: !! 580 /* get the arguments back.. */
473 handle_trap_reserved: !! 581 ldq $16, SP_OFF+24($sp)
474 call handle_trap_3_c !! 582 ldq $17, SP_OFF+32($sp)
475 br ret_from_exception !! 583 ldq $18, SP_OFF+40($sp)
>> 584 ldq $19, 72($sp)
>> 585 ldq $20, 80($sp)
>> 586 ldq $21, 88($sp)
>> 587
>> 588 /* get the system call pointer.. */
>> 589 lda $1, NR_SYSCALLS($31)
>> 590 lda $2, sys_call_table
>> 591 lda $27, alpha_ni_syscall
>> 592 cmpult $0, $1, $1
>> 593 s8addq $0, $2, $2
>> 594 beq $1, 1f
>> 595 ldq $27, 0($2)
>> 596 1: jsr $26, ($27), sys_gettimeofday
>> 597 ret_from_straced:
>> 598 ldgp $gp, 0($26)
>> 599
>> 600 /* check return.. */
>> 601 blt $0, $strace_error /* the call failed */
>> 602 stq $31, 72($sp) /* a3=0 => no error */
>> 603 $strace_success:
>> 604 stq $0, 0($sp) /* save return value */
>> 605
>> 606 DO_SWITCH_STACK
>> 607 jsr $26, syscall_trace_leave
>> 608 UNDO_SWITCH_STACK
>> 609 br $31, ret_from_sys_call
>> 610
>> 611 .align 3
>> 612 $strace_error:
>> 613 ldq $18, 0($sp) /* old syscall nr (zero if success) */
>> 614 beq $18, $strace_success
>> 615 ldq $19, 72($sp) /* .. and this a3 */
>> 616
>> 617 subq $31, $0, $0 /* with error in v0 */
>> 618 addq $31, 1, $1 /* set a3 for errno return */
>> 619 stq $0, 0($sp)
>> 620 stq $1, 72($sp) /* a3 for return */
>> 621
>> 622 DO_SWITCH_STACK
>> 623 mov $18, $9 /* save old syscall number */
>> 624 mov $19, $10 /* save old a3 */
>> 625 jsr $26, syscall_trace_leave
>> 626 mov $9, $18
>> 627 mov $10, $19
>> 628 UNDO_SWITCH_STACK
>> 629
>> 630 mov $31, $26 /* tell "ret_from_sys_call" we can restart */
>> 631 br ret_from_sys_call
>> 632 CFI_END_OSF_FRAME entSys
>> 633
>> 634 /*
>> 635 * Save and restore the switch stack -- aka the balance of the user context.
>> 636 */
476 637
>> 638 .align 4
>> 639 .type do_switch_stack, @function
>> 640 .cfi_startproc simple
>> 641 .cfi_return_column 64
>> 642 .cfi_def_cfa $sp, 0
>> 643 .cfi_register 64, $1
>> 644 do_switch_stack:
>> 645 lda $sp, -SWITCH_STACK_SIZE($sp)
>> 646 .cfi_adjust_cfa_offset SWITCH_STACK_SIZE
>> 647 stq $9, 0($sp)
>> 648 stq $10, 8($sp)
>> 649 stq $11, 16($sp)
>> 650 stq $12, 24($sp)
>> 651 stq $13, 32($sp)
>> 652 stq $14, 40($sp)
>> 653 stq $15, 48($sp)
>> 654 stq $26, 56($sp)
>> 655 stt $f0, 64($sp)
>> 656 stt $f1, 72($sp)
>> 657 stt $f2, 80($sp)
>> 658 stt $f3, 88($sp)
>> 659 stt $f4, 96($sp)
>> 660 stt $f5, 104($sp)
>> 661 stt $f6, 112($sp)
>> 662 stt $f7, 120($sp)
>> 663 stt $f8, 128($sp)
>> 664 stt $f9, 136($sp)
>> 665 stt $f10, 144($sp)
>> 666 stt $f11, 152($sp)
>> 667 stt $f12, 160($sp)
>> 668 stt $f13, 168($sp)
>> 669 stt $f14, 176($sp)
>> 670 stt $f15, 184($sp)
>> 671 stt $f16, 192($sp)
>> 672 stt $f17, 200($sp)
>> 673 stt $f18, 208($sp)
>> 674 stt $f19, 216($sp)
>> 675 stt $f20, 224($sp)
>> 676 stt $f21, 232($sp)
>> 677 stt $f22, 240($sp)
>> 678 stt $f23, 248($sp)
>> 679 stt $f24, 256($sp)
>> 680 stt $f25, 264($sp)
>> 681 stt $f26, 272($sp)
>> 682 stt $f27, 280($sp)
>> 683 mf_fpcr $f0 # get fpcr
>> 684 stt $f28, 288($sp)
>> 685 stt $f29, 296($sp)
>> 686 stt $f30, 304($sp)
>> 687 stt $f0, 312($sp) # save fpcr in slot of $f31
>> 688 ldt $f0, 64($sp) # dont let "do_switch_stack" change fp state.
>> 689 ret $31, ($1), 1
>> 690 .cfi_endproc
>> 691 .size do_switch_stack, .-do_switch_stack
>> 692
>> 693 .align 4
>> 694 .type undo_switch_stack, @function
>> 695 .cfi_startproc simple
>> 696 .cfi_def_cfa $sp, 0
>> 697 .cfi_register 64, $1
>> 698 undo_switch_stack:
>> 699 ldq $9, 0($sp)
>> 700 ldq $10, 8($sp)
>> 701 ldq $11, 16($sp)
>> 702 ldq $12, 24($sp)
>> 703 ldq $13, 32($sp)
>> 704 ldq $14, 40($sp)
>> 705 ldq $15, 48($sp)
>> 706 ldq $26, 56($sp)
>> 707 ldt $f30, 312($sp) # get saved fpcr
>> 708 ldt $f0, 64($sp)
>> 709 ldt $f1, 72($sp)
>> 710 ldt $f2, 80($sp)
>> 711 ldt $f3, 88($sp)
>> 712 mt_fpcr $f30 # install saved fpcr
>> 713 ldt $f4, 96($sp)
>> 714 ldt $f5, 104($sp)
>> 715 ldt $f6, 112($sp)
>> 716 ldt $f7, 120($sp)
>> 717 ldt $f8, 128($sp)
>> 718 ldt $f9, 136($sp)
>> 719 ldt $f10, 144($sp)
>> 720 ldt $f11, 152($sp)
>> 721 ldt $f12, 160($sp)
>> 722 ldt $f13, 168($sp)
>> 723 ldt $f14, 176($sp)
>> 724 ldt $f15, 184($sp)
>> 725 ldt $f16, 192($sp)
>> 726 ldt $f17, 200($sp)
>> 727 ldt $f18, 208($sp)
>> 728 ldt $f19, 216($sp)
>> 729 ldt $f20, 224($sp)
>> 730 ldt $f21, 232($sp)
>> 731 ldt $f22, 240($sp)
>> 732 ldt $f23, 248($sp)
>> 733 ldt $f24, 256($sp)
>> 734 ldt $f25, 264($sp)
>> 735 ldt $f26, 272($sp)
>> 736 ldt $f27, 280($sp)
>> 737 ldt $f28, 288($sp)
>> 738 ldt $f29, 296($sp)
>> 739 ldt $f30, 304($sp)
>> 740 lda $sp, SWITCH_STACK_SIZE($sp)
>> 741 ret $31, ($1), 1
>> 742 .cfi_endproc
>> 743 .size undo_switch_stack, .-undo_switch_stack
>> 744
477 /* 745 /*
478 * Beware - when entering resume, prev (the cu !! 746 * The meat of the context switch code.
479 * in r4, next (the new task) is in r5, don't !! 747 */
480 * registers. <<
481 */ <<
482 ENTRY(resume) <<
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 <<
497 748
498 ldw r7, TASK_THREAD + THREAD_KPSR( !! 749 .align 4
499 wrctl status, r7 !! 750 .globl alpha_switch_to
>> 751 .type alpha_switch_to, @function
>> 752 .cfi_startproc
>> 753 alpha_switch_to:
>> 754 DO_SWITCH_STACK
>> 755 call_pal PAL_swpctx
>> 756 lda $8, 0x3fff
>> 757 UNDO_SWITCH_STACK
>> 758 bic $sp, $8, $8
>> 759 mov $17, $0
500 ret 760 ret
501 !! 761 .cfi_endproc
502 ENTRY(ret_from_fork) !! 762 .size alpha_switch_to, .-alpha_switch_to
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 <<
511 763
512 /* 764 /*
513 * Kernel user helpers. !! 765 * New processes begin life here.
514 * <<
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 */ 766 */
521 767
522 /* Filling pads with undefined instructions. !! 768 .globl ret_from_fork
523 .macro kuser_pad sym size !! 769 .align 4
524 .if ((. - \sym) & 3) !! 770 .ent ret_from_fork
525 .rept (4 - (. - \sym) & 3) !! 771 ret_from_fork:
526 .byte 0 !! 772 lda $26, ret_from_sys_call
527 .endr !! 773 mov $17, $16
528 .endif !! 774 jmp $31, schedule_tail
529 .rept ((\size - (. - \sym)) / 4) !! 775 .end ret_from_fork
530 .word 0xdeadbeef <<
531 .endr <<
532 .endm <<
533 776
534 .align 6 !! 777 /*
535 .globl __kuser_helper_start !! 778 * ... and new kernel threads - here
536 __kuser_helper_start: !! 779 */
>> 780 .align 4
>> 781 .globl ret_from_kernel_thread
>> 782 .ent ret_from_kernel_thread
>> 783 ret_from_kernel_thread:
>> 784 mov $17, $16
>> 785 jsr $26, schedule_tail
>> 786 mov $9, $27
>> 787 mov $10, $16
>> 788 jsr $26, ($9)
>> 789 mov $31, $19 /* to disable syscall restarts */
>> 790 br $31, ret_to_user
>> 791 .end ret_from_kernel_thread
537 792
538 __kuser_helper_version: !! 793
539 .word ((__kuser_helper_end - __kuser !! 794 /*
>> 795 * Special system calls. Most of these are special in that they either
>> 796 * have to play switch_stack games or in some way use the pt_regs struct.
>> 797 */
540 798
541 __kuser_cmpxchg: !! 799 .macro fork_like name
542 /* !! 800 .align 4
543 * r4 pointer to exchange variable !! 801 .globl alpha_\name
544 * r5 old value !! 802 .ent alpha_\name
545 * r6 new value !! 803 alpha_\name:
546 */ !! 804 .prologue 0
547 cmpxchg_ldw: !! 805 bsr $1, do_switch_stack
548 ldw r2, 0(r4) !! 806 jsr $26, sys_\name
549 sub r2, r2, r5 !! 807 ldq $26, 56($sp)
550 bne r2, zero, cmpxchg_ret !! 808 lda $sp, SWITCH_STACK_SIZE($sp)
551 <<
552 /* We had a match, store the new value <<
553 cmpxchg_stw: <<
554 stw r6, 0(r4) <<
555 cmpxchg_ret: <<
556 ret 809 ret
>> 810 .end alpha_\name
>> 811 .endm
557 812
558 kuser_pad __kuser_cmpxchg, 64 !! 813 fork_like fork
559 !! 814 fork_like vfork
560 .globl __kuser_sigtramp !! 815 fork_like clone
561 __kuser_sigtramp: !! 816
562 movi r2, __NR_rt_sigreturn !! 817 .align 4
563 trap !! 818 .globl sys_sigreturn
564 !! 819 .ent sys_sigreturn
565 kuser_pad __kuser_sigtramp, 64 !! 820 sys_sigreturn:
566 !! 821 .prologue 0
567 .globl __kuser_helper_end !! 822 lda $9, ret_from_straced
568 __kuser_helper_end: !! 823 cmpult $26, $9, $9
>> 824 lda $sp, -SWITCH_STACK_SIZE($sp)
>> 825 jsr $26, do_sigreturn
>> 826 bne $9, 1f
>> 827 jsr $26, syscall_trace_leave
>> 828 1: br $1, undo_switch_stack
>> 829 br ret_from_sys_call
>> 830 .end sys_sigreturn
>> 831
>> 832 .align 4
>> 833 .globl sys_rt_sigreturn
>> 834 .ent sys_rt_sigreturn
>> 835 sys_rt_sigreturn:
>> 836 .prologue 0
>> 837 lda $9, ret_from_straced
>> 838 cmpult $26, $9, $9
>> 839 lda $sp, -SWITCH_STACK_SIZE($sp)
>> 840 jsr $26, do_rt_sigreturn
>> 841 bne $9, 1f
>> 842 jsr $26, syscall_trace_leave
>> 843 1: br $1, undo_switch_stack
>> 844 br ret_from_sys_call
>> 845 .end sys_rt_sigreturn
>> 846
>> 847 .align 4
>> 848 .globl alpha_ni_syscall
>> 849 .ent alpha_ni_syscall
>> 850 alpha_ni_syscall:
>> 851 .prologue 0
>> 852 /* Special because it also implements overflow handling via
>> 853 syscall number 0. And if you recall, zero is a special
>> 854 trigger for "not an error". Store large non-zero there. */
>> 855 lda $0, -ENOSYS
>> 856 unop
>> 857 stq $0, 0($sp)
>> 858 ret
>> 859 .end alpha_ni_syscall
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