Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 1 | /* |
| 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 | |
| 34 | /* The size of a state save frame. */ |
| 35 | #define STATE_SAVE_SIZE (PT_SIZE + STATE_SAVE_ARG_SPACE) |
| 36 | |
| 37 | /* The offset of the struct pt_regs in a `state save frame' on the stack. */ |
| 38 | #define PTO STATE_SAVE_ARG_SPACE /* 24 the space for args */ |
| 39 | |
| 40 | #define C_ENTRY(name) .globl name; .align 4; name |
| 41 | |
| 42 | /* |
| 43 | * Various ways of setting and clearing BIP in flags reg. |
| 44 | * This is mucky, but necessary using microblaze version that |
| 45 | * allows msr ops to write to BIP |
| 46 | */ |
| 47 | #if CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR |
| 48 | .macro clear_bip |
| 49 | msrclr r11, MSR_BIP |
| 50 | nop |
| 51 | .endm |
| 52 | |
| 53 | .macro set_bip |
| 54 | msrset r11, MSR_BIP |
| 55 | nop |
| 56 | .endm |
| 57 | |
| 58 | .macro clear_eip |
| 59 | msrclr r11, MSR_EIP |
| 60 | nop |
| 61 | .endm |
| 62 | |
| 63 | .macro set_ee |
| 64 | msrset r11, MSR_EE |
| 65 | nop |
| 66 | .endm |
| 67 | |
| 68 | .macro disable_irq |
| 69 | msrclr r11, MSR_IE |
| 70 | nop |
| 71 | .endm |
| 72 | |
| 73 | .macro enable_irq |
| 74 | msrset r11, MSR_IE |
| 75 | nop |
| 76 | .endm |
| 77 | |
| 78 | .macro set_ums |
| 79 | msrset r11, MSR_UMS |
| 80 | nop |
| 81 | msrclr r11, MSR_VMS |
| 82 | nop |
| 83 | .endm |
| 84 | |
| 85 | .macro set_vms |
| 86 | msrclr r11, MSR_UMS |
| 87 | nop |
| 88 | msrset r11, MSR_VMS |
| 89 | nop |
| 90 | .endm |
| 91 | |
| 92 | .macro clear_vms_ums |
| 93 | msrclr r11, MSR_VMS |
| 94 | nop |
| 95 | msrclr r11, MSR_UMS |
| 96 | nop |
| 97 | .endm |
| 98 | #else |
| 99 | .macro clear_bip |
| 100 | mfs r11, rmsr |
| 101 | nop |
| 102 | andi r11, r11, ~MSR_BIP |
| 103 | mts rmsr, r11 |
| 104 | nop |
| 105 | .endm |
| 106 | |
| 107 | .macro set_bip |
| 108 | mfs r11, rmsr |
| 109 | nop |
| 110 | ori r11, r11, MSR_BIP |
| 111 | mts rmsr, r11 |
| 112 | nop |
| 113 | .endm |
| 114 | |
| 115 | .macro clear_eip |
| 116 | mfs r11, rmsr |
| 117 | nop |
| 118 | andi r11, r11, ~MSR_EIP |
| 119 | mts rmsr, r11 |
| 120 | nop |
| 121 | .endm |
| 122 | |
| 123 | .macro set_ee |
| 124 | mfs r11, rmsr |
| 125 | nop |
| 126 | ori r11, r11, MSR_EE |
| 127 | mts rmsr, r11 |
| 128 | nop |
| 129 | .endm |
| 130 | |
| 131 | .macro disable_irq |
| 132 | mfs r11, rmsr |
| 133 | nop |
| 134 | andi r11, r11, ~MSR_IE |
| 135 | mts rmsr, r11 |
| 136 | nop |
| 137 | .endm |
| 138 | |
| 139 | .macro enable_irq |
| 140 | mfs r11, rmsr |
| 141 | nop |
| 142 | ori r11, r11, MSR_IE |
| 143 | mts rmsr, r11 |
| 144 | nop |
| 145 | .endm |
| 146 | |
| 147 | .macro set_ums |
| 148 | mfs r11, rmsr |
| 149 | nop |
| 150 | ori r11, r11, MSR_VMS |
| 151 | andni r11, r11, MSR_UMS |
| 152 | mts rmsr, r11 |
| 153 | nop |
| 154 | .endm |
| 155 | |
| 156 | .macro set_vms |
| 157 | mfs r11, rmsr |
| 158 | nop |
| 159 | ori r11, r11, MSR_VMS |
| 160 | andni r11, r11, MSR_UMS |
| 161 | mts rmsr, r11 |
| 162 | nop |
| 163 | .endm |
| 164 | |
| 165 | .macro clear_vms_ums |
| 166 | mfs r11, rmsr |
| 167 | nop |
| 168 | andni r11, r11, (MSR_VMS|MSR_UMS) |
| 169 | mts rmsr,r11 |
| 170 | nop |
| 171 | .endm |
| 172 | #endif |
| 173 | |
| 174 | /* Define how to call high-level functions. With MMU, virtual mode must be |
| 175 | * enabled when calling the high-level function. Clobbers R11. |
| 176 | * VM_ON, VM_OFF, DO_JUMP_BIPCLR, DO_CALL |
| 177 | */ |
| 178 | |
| 179 | /* turn on virtual protected mode save */ |
| 180 | #define VM_ON \ |
| 181 | set_ums; \ |
| 182 | rted r0, 2f; \ |
| 183 | 2: nop; |
| 184 | |
| 185 | /* turn off virtual protected mode save and user mode save*/ |
| 186 | #define VM_OFF \ |
| 187 | clear_vms_ums; \ |
| 188 | rted r0, TOPHYS(1f); \ |
| 189 | 1: nop; |
| 190 | |
| 191 | #define SAVE_REGS \ |
| 192 | swi r2, r1, PTO+PT_R2; /* Save SDA */ \ |
| 193 | swi r5, r1, PTO+PT_R5; \ |
| 194 | swi r6, r1, PTO+PT_R6; \ |
| 195 | swi r7, r1, PTO+PT_R7; \ |
| 196 | swi r8, r1, PTO+PT_R8; \ |
| 197 | swi r9, r1, PTO+PT_R9; \ |
| 198 | swi r10, r1, PTO+PT_R10; \ |
| 199 | swi r11, r1, PTO+PT_R11; /* save clobbered regs after rval */\ |
| 200 | swi r12, r1, PTO+PT_R12; \ |
| 201 | swi r13, r1, PTO+PT_R13; /* Save SDA2 */ \ |
| 202 | swi r14, r1, PTO+PT_PC; /* PC, before IRQ/trap */ \ |
| 203 | swi r15, r1, PTO+PT_R15; /* Save LP */ \ |
| 204 | swi r18, r1, PTO+PT_R18; /* Save asm scratch reg */ \ |
| 205 | swi r19, r1, PTO+PT_R19; \ |
| 206 | swi r20, r1, PTO+PT_R20; \ |
| 207 | swi r21, r1, PTO+PT_R21; \ |
| 208 | swi r22, r1, PTO+PT_R22; \ |
| 209 | swi r23, r1, PTO+PT_R23; \ |
| 210 | swi r24, r1, PTO+PT_R24; \ |
| 211 | swi r25, r1, PTO+PT_R25; \ |
| 212 | swi r26, r1, PTO+PT_R26; \ |
| 213 | swi r27, r1, PTO+PT_R27; \ |
| 214 | swi r28, r1, PTO+PT_R28; \ |
| 215 | swi r29, r1, PTO+PT_R29; \ |
| 216 | swi r30, r1, PTO+PT_R30; \ |
| 217 | swi r31, r1, PTO+PT_R31; /* Save current task reg */ \ |
| 218 | mfs r11, rmsr; /* save MSR */ \ |
| 219 | nop; \ |
| 220 | swi r11, r1, PTO+PT_MSR; |
| 221 | |
| 222 | #define RESTORE_REGS \ |
| 223 | lwi r11, r1, PTO+PT_MSR; \ |
| 224 | mts rmsr , r11; \ |
| 225 | nop; \ |
| 226 | lwi r2, r1, PTO+PT_R2; /* restore SDA */ \ |
| 227 | lwi r5, r1, PTO+PT_R5; \ |
| 228 | lwi r6, r1, PTO+PT_R6; \ |
| 229 | lwi r7, r1, PTO+PT_R7; \ |
| 230 | lwi r8, r1, PTO+PT_R8; \ |
| 231 | lwi r9, r1, PTO+PT_R9; \ |
| 232 | lwi r10, r1, PTO+PT_R10; \ |
| 233 | lwi r11, r1, PTO+PT_R11; /* restore clobbered regs after rval */\ |
| 234 | lwi r12, r1, PTO+PT_R12; \ |
| 235 | lwi r13, r1, PTO+PT_R13; /* restore SDA2 */ \ |
| 236 | lwi r14, r1, PTO+PT_PC; /* RESTORE_LINK PC, before IRQ/trap */\ |
| 237 | lwi r15, r1, PTO+PT_R15; /* restore LP */ \ |
| 238 | lwi r18, r1, PTO+PT_R18; /* restore asm scratch reg */ \ |
| 239 | lwi r19, r1, PTO+PT_R19; \ |
| 240 | lwi r20, r1, PTO+PT_R20; \ |
| 241 | lwi r21, r1, PTO+PT_R21; \ |
| 242 | lwi r22, r1, PTO+PT_R22; \ |
| 243 | lwi r23, r1, PTO+PT_R23; \ |
| 244 | lwi r24, r1, PTO+PT_R24; \ |
| 245 | lwi r25, r1, PTO+PT_R25; \ |
| 246 | lwi r26, r1, PTO+PT_R26; \ |
| 247 | lwi r27, r1, PTO+PT_R27; \ |
| 248 | lwi r28, r1, PTO+PT_R28; \ |
| 249 | lwi r29, r1, PTO+PT_R29; \ |
| 250 | lwi r30, r1, PTO+PT_R30; \ |
| 251 | lwi r31, r1, PTO+PT_R31; /* Restore cur task reg */ |
| 252 | |
| 253 | .text |
| 254 | |
| 255 | /* |
| 256 | * User trap. |
| 257 | * |
| 258 | * System calls are handled here. |
| 259 | * |
| 260 | * Syscall protocol: |
| 261 | * Syscall number in r12, args in r5-r10 |
| 262 | * Return value in r3 |
| 263 | * |
| 264 | * Trap entered via brki instruction, so BIP bit is set, and interrupts |
| 265 | * are masked. This is nice, means we don't have to CLI before state save |
| 266 | */ |
| 267 | C_ENTRY(_user_exception): |
| 268 | swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ |
| 269 | addi r14, r14, 4 /* return address is 4 byte after call */ |
| 270 | swi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* Save r11 */ |
| 271 | |
| 272 | lwi r11, r0, TOPHYS(PER_CPU(KM));/* See if already in kernel mode.*/ |
| 273 | beqi r11, 1f; /* Jump ahead if coming from user */ |
| 274 | /* Kernel-mode state save. */ |
| 275 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/ |
| 276 | tophys(r1,r11); |
| 277 | swi r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */ |
| 278 | lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */ |
| 279 | |
| 280 | addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ |
| 281 | SAVE_REGS |
| 282 | |
| 283 | addi r11, r0, 1; /* Was in kernel-mode. */ |
| 284 | swi r11, r1, PTO+PT_MODE; /* pt_regs -> kernel mode */ |
| 285 | brid 2f; |
| 286 | nop; /* Fill delay slot */ |
| 287 | |
| 288 | /* User-mode state save. */ |
| 289 | 1: |
| 290 | lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */ |
| 291 | lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */ |
| 292 | tophys(r1,r1); |
| 293 | lwi r1, r1, TS_THREAD_INFO; /* get stack from task_struct */ |
| 294 | /* calculate kernel stack pointer from task struct 8k */ |
| 295 | addik r1, r1, THREAD_SIZE; |
| 296 | tophys(r1,r1); |
| 297 | |
| 298 | addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ |
| 299 | SAVE_REGS |
| 300 | |
| 301 | swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */ |
| 302 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); |
| 303 | swi r11, r1, PTO+PT_R1; /* Store user SP. */ |
| 304 | addi r11, r0, 1; |
| 305 | swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode. */ |
| 306 | 2: lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */ |
| 307 | /* Save away the syscall number. */ |
| 308 | swi r12, r1, PTO+PT_R0; |
| 309 | tovirt(r1,r1) |
| 310 | |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 311 | /* where the trap should return need -8 to adjust for rtsd r15, 8*/ |
| 312 | /* Jump to the appropriate function for the system call number in r12 |
| 313 | * (r12 is not preserved), or return an error if r12 is not valid. The LP |
| 314 | * register should point to the location where |
| 315 | * the called function should return. [note that MAKE_SYS_CALL uses label 1] */ |
Michal Simek | 2357548 | 2009-08-24 13:26:04 +0200 | [diff] [blame^] | 316 | |
| 317 | # Step into virtual mode. |
| 318 | set_vms; |
| 319 | addik r11, r0, 3f |
| 320 | rtid r11, 0 |
| 321 | nop |
| 322 | 3: |
| 323 | add r11, r0, CURRENT_TASK /* Get current task ptr into r11 */ |
| 324 | lwi r11, r11, TS_THREAD_INFO /* get thread info */ |
| 325 | lwi r11, r11, TI_FLAGS /* get flags in thread info */ |
| 326 | andi r11, r11, _TIF_WORK_SYSCALL_MASK |
| 327 | beqi r11, 4f |
| 328 | |
| 329 | addik r3, r0, -ENOSYS |
| 330 | swi r3, r1, PTO + PT_R3 |
| 331 | brlid r15, do_syscall_trace_enter |
| 332 | addik r5, r1, PTO + PT_R0 |
| 333 | |
| 334 | # do_syscall_trace_enter returns the new syscall nr. |
| 335 | addk r12, r0, r3 |
| 336 | lwi r5, r1, PTO+PT_R5; |
| 337 | lwi r6, r1, PTO+PT_R6; |
| 338 | lwi r7, r1, PTO+PT_R7; |
| 339 | lwi r8, r1, PTO+PT_R8; |
| 340 | lwi r9, r1, PTO+PT_R9; |
| 341 | lwi r10, r1, PTO+PT_R10; |
| 342 | 4: |
| 343 | /* Jump to the appropriate function for the system call number in r12 |
| 344 | * (r12 is not preserved), or return an error if r12 is not valid. |
| 345 | * The LP register should point to the location where the called function |
| 346 | * should return. [note that MAKE_SYS_CALL uses label 1] */ |
| 347 | /* See if the system call number is valid */ |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 348 | addi r11, r12, -__NR_syscalls; |
Michal Simek | 2357548 | 2009-08-24 13:26:04 +0200 | [diff] [blame^] | 349 | bgei r11,5f; |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 350 | /* Figure out which function to use for this system call. */ |
| 351 | /* Note Microblaze barrel shift is optional, so don't rely on it */ |
| 352 | add r12, r12, r12; /* convert num -> ptr */ |
| 353 | add r12, r12, r12; |
| 354 | |
| 355 | /* Trac syscalls and stored them to r0_ram */ |
Michal Simek | 2357548 | 2009-08-24 13:26:04 +0200 | [diff] [blame^] | 356 | lwi r3, r12, 0x400 + r0_ram |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 357 | addi r3, r3, 1 |
Michal Simek | 2357548 | 2009-08-24 13:26:04 +0200 | [diff] [blame^] | 358 | swi r3, r12, 0x400 + r0_ram |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 359 | |
Michal Simek | 2357548 | 2009-08-24 13:26:04 +0200 | [diff] [blame^] | 360 | # Find and jump into the syscall handler. |
| 361 | lwi r12, r12, sys_call_table |
| 362 | /* where the trap should return need -8 to adjust for rtsd r15, 8 */ |
| 363 | la r15, r0, ret_from_trap-8 |
| 364 | bra r12 |
| 365 | |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 366 | /* The syscall number is invalid, return an error. */ |
Michal Simek | 2357548 | 2009-08-24 13:26:04 +0200 | [diff] [blame^] | 367 | 5: |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 368 | addi r3, r0, -ENOSYS; |
| 369 | rtsd r15,8; /* looks like a normal subroutine return */ |
| 370 | or r0, r0, r0 |
| 371 | |
| 372 | |
Michal Simek | 2357548 | 2009-08-24 13:26:04 +0200 | [diff] [blame^] | 373 | /* Entry point used to return from a syscall/trap */ |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 374 | /* We re-enable BIP bit before state restore */ |
| 375 | C_ENTRY(ret_from_trap): |
| 376 | set_bip; /* Ints masked for state restore*/ |
| 377 | lwi r11, r1, PTO+PT_MODE; |
| 378 | /* See if returning to kernel mode, if so, skip resched &c. */ |
| 379 | bnei r11, 2f; |
| 380 | |
| 381 | /* We're returning to user mode, so check for various conditions that |
| 382 | * trigger rescheduling. */ |
Michal Simek | 2357548 | 2009-08-24 13:26:04 +0200 | [diff] [blame^] | 383 | # FIXME: Restructure all these flag checks. |
| 384 | add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ |
| 385 | lwi r11, r11, TS_THREAD_INFO; /* get thread info */ |
| 386 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
| 387 | andi r11, r11, _TIF_WORK_SYSCALL_MASK |
| 388 | beqi r11, 1f |
| 389 | |
| 390 | swi r3, r1, PTO + PT_R3 |
| 391 | swi r4, r1, PTO + PT_R4 |
| 392 | brlid r15, do_syscall_trace_leave |
| 393 | addik r5, r1, PTO + PT_R0 |
| 394 | lwi r3, r1, PTO + PT_R3 |
| 395 | lwi r4, r1, PTO + PT_R4 |
| 396 | 1: |
| 397 | |
| 398 | /* We're returning to user mode, so check for various conditions that |
| 399 | * trigger rescheduling. */ |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 400 | /* Get current task ptr into r11 */ |
| 401 | add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ |
| 402 | lwi r11, r11, TS_THREAD_INFO; /* get thread info */ |
| 403 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
| 404 | andi r11, r11, _TIF_NEED_RESCHED; |
| 405 | beqi r11, 5f; |
| 406 | |
| 407 | swi r3, r1, PTO + PT_R3; /* store syscall result */ |
| 408 | swi r4, r1, PTO + PT_R4; |
| 409 | bralid r15, schedule; /* Call scheduler */ |
| 410 | nop; /* delay slot */ |
| 411 | lwi r3, r1, PTO + PT_R3; /* restore syscall result */ |
| 412 | lwi r4, r1, PTO + PT_R4; |
| 413 | |
| 414 | /* Maybe handle a signal */ |
| 415 | 5: add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ |
| 416 | lwi r11, r11, TS_THREAD_INFO; /* get thread info */ |
| 417 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
| 418 | andi r11, r11, _TIF_SIGPENDING; |
| 419 | beqi r11, 1f; /* Signals to handle, handle them */ |
| 420 | |
| 421 | swi r3, r1, PTO + PT_R3; /* store syscall result */ |
| 422 | swi r4, r1, PTO + PT_R4; |
| 423 | la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ |
| 424 | add r6, r0, r0; /* Arg 2: sigset_t *oldset */ |
| 425 | addi r7, r0, 1; /* Arg 3: int in_syscall */ |
| 426 | bralid r15, do_signal; /* Handle any signals */ |
| 427 | nop; |
| 428 | lwi r3, r1, PTO + PT_R3; /* restore syscall result */ |
| 429 | lwi r4, r1, PTO + PT_R4; |
| 430 | |
| 431 | /* Finally, return to user state. */ |
| 432 | 1: swi r0, r0, PER_CPU(KM); /* Now officially in user state. */ |
| 433 | add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ |
| 434 | swi r11, r0, PER_CPU(CURRENT_SAVE); /* save current */ |
| 435 | VM_OFF; |
| 436 | tophys(r1,r1); |
| 437 | RESTORE_REGS; |
| 438 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ |
| 439 | lwi r1, r1, PT_R1 - PT_SIZE;/* Restore user stack pointer. */ |
| 440 | bri 6f; |
| 441 | |
| 442 | /* Return to kernel state. */ |
| 443 | 2: VM_OFF; |
| 444 | tophys(r1,r1); |
| 445 | RESTORE_REGS; |
| 446 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ |
| 447 | tovirt(r1,r1); |
| 448 | 6: |
| 449 | TRAP_return: /* Make global symbol for debugging */ |
| 450 | rtbd r14, 0; /* Instructions to return from an IRQ */ |
| 451 | nop; |
| 452 | |
| 453 | |
| 454 | /* These syscalls need access to the struct pt_regs on the stack, so we |
| 455 | implement them in assembly (they're basically all wrappers anyway). */ |
| 456 | |
| 457 | C_ENTRY(sys_fork_wrapper): |
| 458 | addi r5, r0, SIGCHLD /* Arg 0: flags */ |
| 459 | lwi r6, r1, PTO+PT_R1 /* Arg 1: child SP (use parent's) */ |
| 460 | la r7, r1, PTO /* Arg 2: parent context */ |
| 461 | add r8. r0, r0 /* Arg 3: (unused) */ |
| 462 | add r9, r0, r0; /* Arg 4: (unused) */ |
| 463 | add r10, r0, r0; /* Arg 5: (unused) */ |
| 464 | brid do_fork /* Do real work (tail-call) */ |
| 465 | nop; |
| 466 | |
| 467 | /* This the initial entry point for a new child thread, with an appropriate |
| 468 | stack in place that makes it look the the child is in the middle of an |
| 469 | syscall. This function is actually `returned to' from switch_thread |
| 470 | (copy_thread makes ret_from_fork the return address in each new thread's |
| 471 | saved context). */ |
| 472 | C_ENTRY(ret_from_fork): |
| 473 | bralid r15, schedule_tail; /* ...which is schedule_tail's arg */ |
| 474 | add r3, r5, r0; /* switch_thread returns the prev task */ |
| 475 | /* ( in the delay slot ) */ |
| 476 | add r3, r0, r0; /* Child's fork call should return 0. */ |
| 477 | brid ret_from_trap; /* Do normal trap return */ |
| 478 | nop; |
| 479 | |
Arnd Bergmann | e513588 | 2009-06-18 19:55:30 +0200 | [diff] [blame] | 480 | C_ENTRY(sys_vfork): |
| 481 | brid microblaze_vfork /* Do real work (tail-call) */ |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 482 | la r5, r1, PTO |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 483 | |
Arnd Bergmann | e513588 | 2009-06-18 19:55:30 +0200 | [diff] [blame] | 484 | C_ENTRY(sys_clone): |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 485 | bnei r6, 1f; /* See if child SP arg (arg 1) is 0. */ |
| 486 | lwi r6, r1, PTO+PT_R1; /* If so, use paret's stack ptr */ |
| 487 | 1: la r7, r1, PTO; /* Arg 2: parent context */ |
| 488 | add r8, r0, r0; /* Arg 3: (unused) */ |
| 489 | add r9, r0, r0; /* Arg 4: (unused) */ |
| 490 | add r10, r0, r0; /* Arg 5: (unused) */ |
| 491 | brid do_fork /* Do real work (tail-call) */ |
| 492 | nop; |
| 493 | |
Arnd Bergmann | e513588 | 2009-06-18 19:55:30 +0200 | [diff] [blame] | 494 | C_ENTRY(sys_execve): |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 495 | la r8, r1, PTO; /* add user context as 4th arg */ |
Arnd Bergmann | e513588 | 2009-06-18 19:55:30 +0200 | [diff] [blame] | 496 | brid microblaze_execve; /* Do real work (tail-call).*/ |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 497 | nop; |
| 498 | |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 499 | C_ENTRY(sys_rt_sigsuspend_wrapper): |
| 500 | swi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ |
| 501 | swi r4, r1, PTO+PT_R4; |
| 502 | la r7, r1, PTO; /* add user context as 3rd arg */ |
| 503 | brlid r15, sys_rt_sigsuspend; /* Do real work.*/ |
| 504 | nop; |
| 505 | lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ |
| 506 | lwi r4, r1, PTO+PT_R4; |
| 507 | bri ret_from_trap /* fall through will not work here due to align */ |
| 508 | nop; |
| 509 | |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 510 | C_ENTRY(sys_rt_sigreturn_wrapper): |
| 511 | swi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ |
| 512 | swi r4, r1, PTO+PT_R4; |
| 513 | la r5, r1, PTO; /* add user context as 1st arg */ |
| 514 | brlid r15, sys_rt_sigreturn /* Do real work */ |
| 515 | nop; |
| 516 | lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ |
| 517 | lwi r4, r1, PTO+PT_R4; |
| 518 | bri ret_from_trap /* fall through will not work here due to align */ |
| 519 | nop; |
| 520 | |
| 521 | /* |
| 522 | * HW EXCEPTION rutine start |
| 523 | */ |
| 524 | |
| 525 | #define SAVE_STATE \ |
| 526 | swi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* Save r11 */ \ |
| 527 | set_bip; /*equalize initial state for all possible entries*/\ |
| 528 | clear_eip; \ |
| 529 | enable_irq; \ |
| 530 | set_ee; \ |
| 531 | /* See if already in kernel mode.*/ \ |
| 532 | lwi r11, r0, TOPHYS(PER_CPU(KM)); \ |
| 533 | beqi r11, 1f; /* Jump ahead if coming from user */\ |
| 534 | /* Kernel-mode state save. */ \ |
| 535 | /* Reload kernel stack-ptr. */ \ |
| 536 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \ |
| 537 | tophys(r1,r11); \ |
| 538 | swi r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */ \ |
| 539 | lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */\ |
| 540 | addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */\ |
| 541 | /* store return registers separately because \ |
| 542 | * this macros is use for others exceptions */ \ |
| 543 | swi r3, r1, PTO + PT_R3; \ |
| 544 | swi r4, r1, PTO + PT_R4; \ |
| 545 | SAVE_REGS \ |
| 546 | /* PC, before IRQ/trap - this is one instruction above */ \ |
| 547 | swi r17, r1, PTO+PT_PC; \ |
| 548 | \ |
| 549 | addi r11, r0, 1; /* Was in kernel-mode. */ \ |
| 550 | swi r11, r1, PTO+PT_MODE; \ |
| 551 | brid 2f; \ |
| 552 | nop; /* Fill delay slot */ \ |
| 553 | 1: /* User-mode state save. */ \ |
| 554 | lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */\ |
| 555 | lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */\ |
| 556 | tophys(r1,r1); \ |
| 557 | lwi r1, r1, TS_THREAD_INFO; /* get the thread info */ \ |
| 558 | addik r1, r1, THREAD_SIZE; /* calculate kernel stack pointer */\ |
| 559 | tophys(r1,r1); \ |
| 560 | \ |
| 561 | addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */\ |
| 562 | /* store return registers separately because this macros \ |
| 563 | * is use for others exceptions */ \ |
| 564 | swi r3, r1, PTO + PT_R3; \ |
| 565 | swi r4, r1, PTO + PT_R4; \ |
| 566 | SAVE_REGS \ |
| 567 | /* PC, before IRQ/trap - this is one instruction above FIXME*/ \ |
| 568 | swi r17, r1, PTO+PT_PC; \ |
| 569 | \ |
| 570 | swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */ \ |
| 571 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \ |
| 572 | swi r11, r1, PTO+PT_R1; /* Store user SP. */ \ |
| 573 | addi r11, r0, 1; \ |
| 574 | swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode.*/\ |
| 575 | 2: lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */\ |
| 576 | /* Save away the syscall number. */ \ |
| 577 | swi r0, r1, PTO+PT_R0; \ |
| 578 | tovirt(r1,r1) |
| 579 | |
| 580 | C_ENTRY(full_exception_trap): |
| 581 | swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ |
| 582 | /* adjust exception address for privileged instruction |
| 583 | * for finding where is it */ |
| 584 | addik r17, r17, -4 |
| 585 | SAVE_STATE /* Save registers */ |
| 586 | /* FIXME this can be store directly in PT_ESR reg. |
| 587 | * I tested it but there is a fault */ |
| 588 | /* where the trap should return need -8 to adjust for rtsd r15, 8 */ |
| 589 | la r15, r0, ret_from_exc - 8 |
| 590 | la r5, r1, PTO /* parameter struct pt_regs * regs */ |
| 591 | mfs r6, resr |
| 592 | nop |
| 593 | mfs r7, rfsr; /* save FSR */ |
| 594 | nop |
| 595 | la r12, r0, full_exception |
| 596 | set_vms; |
| 597 | rtbd r12, 0; |
| 598 | nop; |
| 599 | |
| 600 | /* |
| 601 | * Unaligned data trap. |
| 602 | * |
| 603 | * Unaligned data trap last on 4k page is handled here. |
| 604 | * |
| 605 | * Trap entered via exception, so EE bit is set, and interrupts |
| 606 | * are masked. This is nice, means we don't have to CLI before state save |
| 607 | * |
| 608 | * The assembler routine is in "arch/microblaze/kernel/hw_exception_handler.S" |
| 609 | */ |
| 610 | C_ENTRY(unaligned_data_trap): |
| 611 | swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ |
| 612 | SAVE_STATE /* Save registers.*/ |
| 613 | /* where the trap should return need -8 to adjust for rtsd r15, 8 */ |
| 614 | la r15, r0, ret_from_exc-8 |
| 615 | mfs r3, resr /* ESR */ |
| 616 | nop |
| 617 | mfs r4, rear /* EAR */ |
| 618 | nop |
| 619 | la r7, r1, PTO /* parameter struct pt_regs * regs */ |
| 620 | la r12, r0, _unaligned_data_exception |
| 621 | set_vms; |
| 622 | rtbd r12, 0; /* interrupts enabled */ |
| 623 | nop; |
| 624 | |
| 625 | /* |
| 626 | * Page fault traps. |
| 627 | * |
| 628 | * If the real exception handler (from hw_exception_handler.S) didn't find |
| 629 | * the mapping for the process, then we're thrown here to handle such situation. |
| 630 | * |
| 631 | * Trap entered via exceptions, so EE bit is set, and interrupts |
| 632 | * are masked. This is nice, means we don't have to CLI before state save |
| 633 | * |
| 634 | * Build a standard exception frame for TLB Access errors. All TLB exceptions |
| 635 | * will bail out to this point if they can't resolve the lightweight TLB fault. |
| 636 | * |
| 637 | * The C function called is in "arch/microblaze/mm/fault.c", declared as: |
| 638 | * void do_page_fault(struct pt_regs *regs, |
| 639 | * unsigned long address, |
| 640 | * unsigned long error_code) |
| 641 | */ |
| 642 | /* data and intruction trap - which is choose is resolved int fault.c */ |
| 643 | C_ENTRY(page_fault_data_trap): |
| 644 | swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ |
| 645 | SAVE_STATE /* Save registers.*/ |
| 646 | /* where the trap should return need -8 to adjust for rtsd r15, 8 */ |
| 647 | la r15, r0, ret_from_exc-8 |
| 648 | la r5, r1, PTO /* parameter struct pt_regs * regs */ |
| 649 | mfs r6, rear /* parameter unsigned long address */ |
| 650 | nop |
| 651 | mfs r7, resr /* parameter unsigned long error_code */ |
| 652 | nop |
| 653 | la r12, r0, do_page_fault |
| 654 | set_vms; |
| 655 | rtbd r12, 0; /* interrupts enabled */ |
| 656 | nop; |
| 657 | |
| 658 | C_ENTRY(page_fault_instr_trap): |
| 659 | swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ |
| 660 | SAVE_STATE /* Save registers.*/ |
| 661 | /* where the trap should return need -8 to adjust for rtsd r15, 8 */ |
| 662 | la r15, r0, ret_from_exc-8 |
| 663 | la r5, r1, PTO /* parameter struct pt_regs * regs */ |
| 664 | mfs r6, rear /* parameter unsigned long address */ |
| 665 | nop |
| 666 | ori r7, r0, 0 /* parameter unsigned long error_code */ |
| 667 | la r12, r0, do_page_fault |
| 668 | set_vms; |
| 669 | rtbd r12, 0; /* interrupts enabled */ |
| 670 | nop; |
| 671 | |
| 672 | /* Entry point used to return from an exception. */ |
| 673 | C_ENTRY(ret_from_exc): |
| 674 | set_bip; /* Ints masked for state restore*/ |
| 675 | lwi r11, r1, PTO+PT_MODE; |
| 676 | bnei r11, 2f; /* See if returning to kernel mode, */ |
| 677 | /* ... if so, skip resched &c. */ |
| 678 | |
| 679 | /* We're returning to user mode, so check for various conditions that |
| 680 | trigger rescheduling. */ |
| 681 | /* Get current task ptr into r11 */ |
| 682 | add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ |
| 683 | lwi r11, r11, TS_THREAD_INFO; /* get thread info */ |
| 684 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
| 685 | andi r11, r11, _TIF_NEED_RESCHED; |
| 686 | beqi r11, 5f; |
| 687 | |
| 688 | /* Call the scheduler before returning from a syscall/trap. */ |
| 689 | bralid r15, schedule; /* Call scheduler */ |
| 690 | nop; /* delay slot */ |
| 691 | |
| 692 | /* Maybe handle a signal */ |
| 693 | 5: add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ |
| 694 | lwi r11, r11, TS_THREAD_INFO; /* get thread info */ |
| 695 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
| 696 | andi r11, r11, _TIF_SIGPENDING; |
| 697 | beqi r11, 1f; /* Signals to handle, handle them */ |
| 698 | |
| 699 | /* |
| 700 | * Handle a signal return; Pending signals should be in r18. |
| 701 | * |
| 702 | * Not all registers are saved by the normal trap/interrupt entry |
| 703 | * points (for instance, call-saved registers (because the normal |
| 704 | * C-compiler calling sequence in the kernel makes sure they're |
| 705 | * preserved), and call-clobbered registers in the case of |
| 706 | * traps), but signal handlers may want to examine or change the |
| 707 | * complete register state. Here we save anything not saved by |
| 708 | * the normal entry sequence, so that it may be safely restored |
| 709 | * (in a possibly modified form) after do_signal returns. |
| 710 | * store return registers separately because this macros is use |
| 711 | * for others exceptions */ |
| 712 | swi r3, r1, PTO + PT_R3; |
| 713 | swi r4, r1, PTO + PT_R4; |
| 714 | la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ |
| 715 | add r6, r0, r0; /* Arg 2: sigset_t *oldset */ |
| 716 | addi r7, r0, 0; /* Arg 3: int in_syscall */ |
| 717 | bralid r15, do_signal; /* Handle any signals */ |
| 718 | nop; |
| 719 | lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ |
| 720 | lwi r4, r1, PTO+PT_R4; |
| 721 | |
| 722 | /* Finally, return to user state. */ |
| 723 | 1: swi r0, r0, PER_CPU(KM); /* Now officially in user state. */ |
| 724 | add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ |
| 725 | swi r11, r0, PER_CPU(CURRENT_SAVE); /* save current */ |
| 726 | VM_OFF; |
| 727 | tophys(r1,r1); |
| 728 | |
| 729 | lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ |
| 730 | lwi r4, r1, PTO+PT_R4; |
| 731 | RESTORE_REGS; |
| 732 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ |
| 733 | |
| 734 | lwi r1, r1, PT_R1 - PT_SIZE; /* Restore user stack pointer. */ |
| 735 | bri 6f; |
| 736 | /* Return to kernel state. */ |
| 737 | 2: VM_OFF; |
| 738 | tophys(r1,r1); |
| 739 | lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ |
| 740 | lwi r4, r1, PTO+PT_R4; |
| 741 | RESTORE_REGS; |
| 742 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ |
| 743 | |
| 744 | tovirt(r1,r1); |
| 745 | 6: |
| 746 | EXC_return: /* Make global symbol for debugging */ |
| 747 | rtbd r14, 0; /* Instructions to return from an IRQ */ |
| 748 | nop; |
| 749 | |
| 750 | /* |
| 751 | * HW EXCEPTION rutine end |
| 752 | */ |
| 753 | |
| 754 | /* |
| 755 | * Hardware maskable interrupts. |
| 756 | * |
| 757 | * The stack-pointer (r1) should have already been saved to the memory |
| 758 | * location PER_CPU(ENTRY_SP). |
| 759 | */ |
| 760 | C_ENTRY(_interrupt): |
| 761 | /* MS: we are in physical address */ |
| 762 | /* Save registers, switch to proper stack, convert SP to virtual.*/ |
| 763 | swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) |
| 764 | swi r11, r0, TOPHYS(PER_CPU(R11_SAVE)); |
| 765 | /* MS: See if already in kernel mode. */ |
| 766 | lwi r11, r0, TOPHYS(PER_CPU(KM)); |
| 767 | beqi r11, 1f; /* MS: Jump ahead if coming from user */ |
| 768 | |
| 769 | /* Kernel-mode state save. */ |
| 770 | or r11, r1, r0 |
| 771 | tophys(r1,r11); /* MS: I have in r1 physical address where stack is */ |
| 772 | /* MS: Save original SP - position PT_R1 to next stack frame 4 *1 - 152*/ |
| 773 | swi r11, r1, (PT_R1 - PT_SIZE); |
| 774 | /* MS: restore r11 because of saving in SAVE_REGS */ |
| 775 | lwi r11, r0, TOPHYS(PER_CPU(R11_SAVE)); |
| 776 | /* save registers */ |
| 777 | /* MS: Make room on the stack -> activation record */ |
| 778 | addik r1, r1, -STATE_SAVE_SIZE; |
| 779 | /* MS: store return registers separately because |
| 780 | * this macros is use for others exceptions */ |
| 781 | swi r3, r1, PTO + PT_R3; |
| 782 | swi r4, r1, PTO + PT_R4; |
| 783 | SAVE_REGS |
| 784 | /* MS: store mode */ |
| 785 | addi r11, r0, 1; /* MS: Was in kernel-mode. */ |
| 786 | swi r11, r1, PTO + PT_MODE; /* MS: and save it */ |
| 787 | brid 2f; |
| 788 | nop; /* MS: Fill delay slot */ |
| 789 | |
| 790 | 1: |
| 791 | /* User-mode state save. */ |
| 792 | /* MS: restore r11 -> FIXME move before SAVE_REG */ |
| 793 | lwi r11, r0, TOPHYS(PER_CPU(R11_SAVE)); |
| 794 | /* MS: get the saved current */ |
| 795 | lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); |
| 796 | tophys(r1,r1); |
| 797 | lwi r1, r1, TS_THREAD_INFO; |
| 798 | addik r1, r1, THREAD_SIZE; |
| 799 | tophys(r1,r1); |
| 800 | /* save registers */ |
| 801 | addik r1, r1, -STATE_SAVE_SIZE; |
| 802 | swi r3, r1, PTO+PT_R3; |
| 803 | swi r4, r1, PTO+PT_R4; |
| 804 | SAVE_REGS |
| 805 | /* calculate mode */ |
| 806 | swi r0, r1, PTO + PT_MODE; |
| 807 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); |
| 808 | swi r11, r1, PTO+PT_R1; |
| 809 | /* setup kernel mode to KM */ |
| 810 | addi r11, r0, 1; |
| 811 | swi r11, r0, TOPHYS(PER_CPU(KM)); |
| 812 | |
| 813 | 2: |
| 814 | lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); |
| 815 | swi r0, r1, PTO + PT_R0; |
| 816 | tovirt(r1,r1) |
| 817 | la r5, r1, PTO; |
| 818 | set_vms; |
| 819 | la r11, r0, do_IRQ; |
| 820 | la r15, r0, irq_call; |
| 821 | irq_call:rtbd r11, 0; |
| 822 | nop; |
| 823 | |
| 824 | /* MS: we are in virtual mode */ |
| 825 | ret_from_irq: |
| 826 | lwi r11, r1, PTO + PT_MODE; |
| 827 | bnei r11, 2f; |
| 828 | |
| 829 | add r11, r0, CURRENT_TASK; |
| 830 | lwi r11, r11, TS_THREAD_INFO; |
| 831 | lwi r11, r11, TI_FLAGS; /* MS: get flags from thread info */ |
| 832 | andi r11, r11, _TIF_NEED_RESCHED; |
| 833 | beqi r11, 5f |
| 834 | bralid r15, schedule; |
| 835 | nop; /* delay slot */ |
| 836 | |
| 837 | /* Maybe handle a signal */ |
| 838 | 5: add r11, r0, CURRENT_TASK; |
| 839 | lwi r11, r11, TS_THREAD_INFO; /* MS: get thread info */ |
| 840 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
| 841 | andi r11, r11, _TIF_SIGPENDING; |
| 842 | beqid r11, no_intr_resched |
| 843 | /* Handle a signal return; Pending signals should be in r18. */ |
| 844 | addi r7, r0, 0; /* Arg 3: int in_syscall */ |
| 845 | la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ |
| 846 | bralid r15, do_signal; /* Handle any signals */ |
| 847 | add r6, r0, r0; /* Arg 2: sigset_t *oldset */ |
| 848 | |
| 849 | /* Finally, return to user state. */ |
| 850 | no_intr_resched: |
| 851 | /* Disable interrupts, we are now committed to the state restore */ |
| 852 | disable_irq |
| 853 | swi r0, r0, PER_CPU(KM); /* MS: Now officially in user state. */ |
| 854 | add r11, r0, CURRENT_TASK; |
| 855 | swi r11, r0, PER_CPU(CURRENT_SAVE); |
| 856 | VM_OFF; |
| 857 | tophys(r1,r1); |
| 858 | lwi r3, r1, PTO + PT_R3; /* MS: restore saved r3, r4 registers */ |
| 859 | lwi r4, r1, PTO + PT_R4; |
| 860 | RESTORE_REGS |
| 861 | addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */ |
| 862 | lwi r1, r1, PT_R1 - PT_SIZE; |
| 863 | bri 6f; |
| 864 | /* MS: Return to kernel state. */ |
| 865 | 2: VM_OFF /* MS: turn off MMU */ |
| 866 | tophys(r1,r1) |
| 867 | lwi r3, r1, PTO + PT_R3; /* MS: restore saved r3, r4 registers */ |
| 868 | lwi r4, r1, PTO + PT_R4; |
| 869 | RESTORE_REGS |
| 870 | addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */ |
| 871 | tovirt(r1,r1); |
| 872 | 6: |
| 873 | IRQ_return: /* MS: Make global symbol for debugging */ |
| 874 | rtid r14, 0 |
| 875 | nop |
| 876 | |
| 877 | /* |
| 878 | * `Debug' trap |
| 879 | * We enter dbtrap in "BIP" (breakpoint) mode. |
| 880 | * So we exit the breakpoint mode with an 'rtbd' and proceed with the |
| 881 | * original dbtrap. |
| 882 | * however, wait to save state first |
| 883 | */ |
| 884 | C_ENTRY(_debug_exception): |
| 885 | /* BIP bit is set on entry, no interrupts can occur */ |
| 886 | swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) |
| 887 | |
| 888 | swi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* Save r11 */ |
| 889 | set_bip; /*equalize initial state for all possible entries*/ |
| 890 | clear_eip; |
| 891 | enable_irq; |
| 892 | lwi r11, r0, TOPHYS(PER_CPU(KM));/* See if already in kernel mode.*/ |
| 893 | beqi r11, 1f; /* Jump ahead if coming from user */ |
| 894 | /* Kernel-mode state save. */ |
| 895 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/ |
| 896 | tophys(r1,r11); |
| 897 | swi r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */ |
| 898 | lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */ |
| 899 | |
| 900 | addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ |
| 901 | swi r3, r1, PTO + PT_R3; |
| 902 | swi r4, r1, PTO + PT_R4; |
| 903 | SAVE_REGS; |
| 904 | |
| 905 | addi r11, r0, 1; /* Was in kernel-mode. */ |
| 906 | swi r11, r1, PTO + PT_MODE; |
| 907 | brid 2f; |
| 908 | nop; /* Fill delay slot */ |
| 909 | 1: /* User-mode state save. */ |
| 910 | lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */ |
| 911 | lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */ |
| 912 | tophys(r1,r1); |
| 913 | lwi r1, r1, TS_THREAD_INFO; /* get the thread info */ |
| 914 | addik r1, r1, THREAD_SIZE; /* calculate kernel stack pointer */ |
| 915 | tophys(r1,r1); |
| 916 | |
| 917 | addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ |
| 918 | swi r3, r1, PTO + PT_R3; |
| 919 | swi r4, r1, PTO + PT_R4; |
| 920 | SAVE_REGS; |
| 921 | |
| 922 | swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */ |
| 923 | lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); |
| 924 | swi r11, r1, PTO+PT_R1; /* Store user SP. */ |
| 925 | addi r11, r0, 1; |
| 926 | swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode. */ |
| 927 | 2: lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */ |
| 928 | /* Save away the syscall number. */ |
| 929 | swi r0, r1, PTO+PT_R0; |
| 930 | tovirt(r1,r1) |
| 931 | |
| 932 | addi r5, r0, SIGTRAP /* send the trap signal */ |
| 933 | add r6, r0, CURRENT_TASK; /* Get current task ptr into r11 */ |
| 934 | addk r7, r0, r0 /* 3rd param zero */ |
| 935 | |
| 936 | set_vms; |
| 937 | la r11, r0, send_sig; |
| 938 | la r15, r0, dbtrap_call; |
| 939 | dbtrap_call: rtbd r11, 0; |
| 940 | nop; |
| 941 | |
| 942 | set_bip; /* Ints masked for state restore*/ |
| 943 | lwi r11, r1, PTO+PT_MODE; |
| 944 | bnei r11, 2f; |
| 945 | |
| 946 | /* Get current task ptr into r11 */ |
| 947 | add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ |
| 948 | lwi r11, r11, TS_THREAD_INFO; /* get thread info */ |
| 949 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
| 950 | andi r11, r11, _TIF_NEED_RESCHED; |
| 951 | beqi r11, 5f; |
| 952 | |
| 953 | /* Call the scheduler before returning from a syscall/trap. */ |
| 954 | |
| 955 | bralid r15, schedule; /* Call scheduler */ |
| 956 | nop; /* delay slot */ |
| 957 | /* XXX Is PT_DTRACE handling needed here? */ |
| 958 | /* XXX m68knommu also checks TASK_STATE & TASK_COUNTER here. */ |
| 959 | |
| 960 | /* Maybe handle a signal */ |
| 961 | 5: add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ |
| 962 | lwi r11, r11, TS_THREAD_INFO; /* get thread info */ |
| 963 | lwi r11, r11, TI_FLAGS; /* get flags in thread info */ |
| 964 | andi r11, r11, _TIF_SIGPENDING; |
| 965 | beqi r11, 1f; /* Signals to handle, handle them */ |
| 966 | |
| 967 | /* Handle a signal return; Pending signals should be in r18. */ |
| 968 | /* Not all registers are saved by the normal trap/interrupt entry |
| 969 | points (for instance, call-saved registers (because the normal |
| 970 | C-compiler calling sequence in the kernel makes sure they're |
| 971 | preserved), and call-clobbered registers in the case of |
| 972 | traps), but signal handlers may want to examine or change the |
| 973 | complete register state. Here we save anything not saved by |
| 974 | the normal entry sequence, so that it may be safely restored |
| 975 | (in a possibly modified form) after do_signal returns. */ |
| 976 | |
| 977 | la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ |
| 978 | add r6, r0, r0; /* Arg 2: sigset_t *oldset */ |
| 979 | addi r7, r0, 0; /* Arg 3: int in_syscall */ |
| 980 | bralid r15, do_signal; /* Handle any signals */ |
| 981 | nop; |
| 982 | |
| 983 | |
| 984 | /* Finally, return to user state. */ |
| 985 | 1: swi r0, r0, PER_CPU(KM); /* Now officially in user state. */ |
| 986 | add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ |
| 987 | swi r11, r0, PER_CPU(CURRENT_SAVE); /* save current */ |
| 988 | VM_OFF; |
| 989 | tophys(r1,r1); |
| 990 | |
| 991 | lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ |
| 992 | lwi r4, r1, PTO+PT_R4; |
| 993 | RESTORE_REGS |
| 994 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ |
| 995 | |
| 996 | |
| 997 | lwi r1, r1, PT_R1 - PT_SIZE; |
| 998 | /* Restore user stack pointer. */ |
| 999 | bri 6f; |
| 1000 | |
| 1001 | /* Return to kernel state. */ |
| 1002 | 2: VM_OFF; |
| 1003 | tophys(r1,r1); |
| 1004 | lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ |
| 1005 | lwi r4, r1, PTO+PT_R4; |
| 1006 | RESTORE_REGS |
| 1007 | addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ |
| 1008 | |
| 1009 | tovirt(r1,r1); |
| 1010 | 6: |
| 1011 | DBTRAP_return: /* Make global symbol for debugging */ |
| 1012 | rtbd r14, 0; /* Instructions to return from an IRQ */ |
| 1013 | nop; |
| 1014 | |
| 1015 | |
| 1016 | |
| 1017 | ENTRY(_switch_to) |
| 1018 | /* prepare return value */ |
| 1019 | addk r3, r0, r31 |
| 1020 | |
| 1021 | /* save registers in cpu_context */ |
| 1022 | /* use r11 and r12, volatile registers, as temp register */ |
| 1023 | /* give start of cpu_context for previous process */ |
| 1024 | addik r11, r5, TI_CPU_CONTEXT |
| 1025 | swi r1, r11, CC_R1 |
| 1026 | swi r2, r11, CC_R2 |
| 1027 | /* skip volatile registers. |
| 1028 | * they are saved on stack when we jumped to _switch_to() */ |
| 1029 | /* dedicated registers */ |
| 1030 | swi r13, r11, CC_R13 |
| 1031 | swi r14, r11, CC_R14 |
| 1032 | swi r15, r11, CC_R15 |
| 1033 | swi r16, r11, CC_R16 |
| 1034 | swi r17, r11, CC_R17 |
| 1035 | swi r18, r11, CC_R18 |
| 1036 | /* save non-volatile registers */ |
| 1037 | swi r19, r11, CC_R19 |
| 1038 | swi r20, r11, CC_R20 |
| 1039 | swi r21, r11, CC_R21 |
| 1040 | swi r22, r11, CC_R22 |
| 1041 | swi r23, r11, CC_R23 |
| 1042 | swi r24, r11, CC_R24 |
| 1043 | swi r25, r11, CC_R25 |
| 1044 | swi r26, r11, CC_R26 |
| 1045 | swi r27, r11, CC_R27 |
| 1046 | swi r28, r11, CC_R28 |
| 1047 | swi r29, r11, CC_R29 |
| 1048 | swi r30, r11, CC_R30 |
| 1049 | /* special purpose registers */ |
| 1050 | mfs r12, rmsr |
| 1051 | nop |
| 1052 | swi r12, r11, CC_MSR |
| 1053 | mfs r12, rear |
| 1054 | nop |
| 1055 | swi r12, r11, CC_EAR |
| 1056 | mfs r12, resr |
| 1057 | nop |
| 1058 | swi r12, r11, CC_ESR |
| 1059 | mfs r12, rfsr |
| 1060 | nop |
| 1061 | swi r12, r11, CC_FSR |
| 1062 | |
| 1063 | /* update r31, the current */ |
| 1064 | lwi r31, r6, TI_TASK/* give me pointer to task which will be next */ |
| 1065 | /* stored it to current_save too */ |
| 1066 | swi r31, r0, PER_CPU(CURRENT_SAVE) |
| 1067 | |
| 1068 | /* get new process' cpu context and restore */ |
| 1069 | /* give me start where start context of next task */ |
| 1070 | addik r11, r6, TI_CPU_CONTEXT |
| 1071 | |
| 1072 | /* non-volatile registers */ |
| 1073 | lwi r30, r11, CC_R30 |
| 1074 | lwi r29, r11, CC_R29 |
| 1075 | lwi r28, r11, CC_R28 |
| 1076 | lwi r27, r11, CC_R27 |
| 1077 | lwi r26, r11, CC_R26 |
| 1078 | lwi r25, r11, CC_R25 |
| 1079 | lwi r24, r11, CC_R24 |
| 1080 | lwi r23, r11, CC_R23 |
| 1081 | lwi r22, r11, CC_R22 |
| 1082 | lwi r21, r11, CC_R21 |
| 1083 | lwi r20, r11, CC_R20 |
| 1084 | lwi r19, r11, CC_R19 |
| 1085 | /* dedicated registers */ |
| 1086 | lwi r18, r11, CC_R18 |
| 1087 | lwi r17, r11, CC_R17 |
| 1088 | lwi r16, r11, CC_R16 |
| 1089 | lwi r15, r11, CC_R15 |
| 1090 | lwi r14, r11, CC_R14 |
| 1091 | lwi r13, r11, CC_R13 |
| 1092 | /* skip volatile registers */ |
| 1093 | lwi r2, r11, CC_R2 |
| 1094 | lwi r1, r11, CC_R1 |
| 1095 | |
| 1096 | /* special purpose registers */ |
| 1097 | lwi r12, r11, CC_FSR |
| 1098 | mts rfsr, r12 |
| 1099 | nop |
| 1100 | lwi r12, r11, CC_MSR |
| 1101 | mts rmsr, r12 |
| 1102 | nop |
| 1103 | |
| 1104 | rtsd r15, 8 |
| 1105 | nop |
| 1106 | |
| 1107 | ENTRY(_reset) |
| 1108 | brai 0x70; /* Jump back to FS-boot */ |
| 1109 | |
| 1110 | ENTRY(_break) |
| 1111 | mfs r5, rmsr |
| 1112 | nop |
| 1113 | swi r5, r0, 0x250 + TOPHYS(r0_ram) |
| 1114 | mfs r5, resr |
| 1115 | nop |
| 1116 | swi r5, r0, 0x254 + TOPHYS(r0_ram) |
| 1117 | bri 0 |
| 1118 | |
| 1119 | /* These are compiled and loaded into high memory, then |
| 1120 | * copied into place in mach_early_setup */ |
| 1121 | .section .init.ivt, "ax" |
| 1122 | .org 0x0 |
| 1123 | /* this is very important - here is the reset vector */ |
| 1124 | /* in current MMU branch you don't care what is here - it is |
| 1125 | * used from bootloader site - but this is correct for FS-BOOT */ |
| 1126 | brai 0x70 |
| 1127 | nop |
| 1128 | brai TOPHYS(_user_exception); /* syscall handler */ |
| 1129 | brai TOPHYS(_interrupt); /* Interrupt handler */ |
| 1130 | brai TOPHYS(_break); /* nmi trap handler */ |
| 1131 | brai TOPHYS(_hw_exception_handler); /* HW exception handler */ |
| 1132 | |
| 1133 | .org 0x60 |
| 1134 | brai TOPHYS(_debug_exception); /* debug trap handler*/ |
| 1135 | |
| 1136 | .section .rodata,"a" |
| 1137 | #include "syscall_table.S" |
| 1138 | |
| 1139 | syscall_table_size=(.-sys_call_table) |
| 1140 | |