Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
Vineet Gupta | 4788a59 | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 8 | * Vineetg: March 2009 (Supporting 2 levels of Interrupts) |
| 9 | * Stack switching code can no longer reliably rely on the fact that |
| 10 | * if we are NOT in user mode, stack is switched to kernel mode. |
| 11 | * e.g. L2 IRQ interrupted a L1 ISR which had not yet completed |
| 12 | * it's prologue including stack switching from user mode |
| 13 | * |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 14 | * Vineetg: Aug 28th 2008: Bug #94984 |
| 15 | * -Zero Overhead Loop Context shd be cleared when entering IRQ/EXcp/Trap |
| 16 | * Normally CPU does this automatically, however when doing FAKE rtie, |
| 17 | * we also need to explicitly do this. The problem in macros |
| 18 | * FAKE_RET_FROM_EXCPN and FAKE_RET_FROM_EXCPN_LOCK_IRQ was that this bit |
| 19 | * was being "CLEARED" rather then "SET". Actually "SET" clears ZOL context |
| 20 | * |
| 21 | * Vineetg: May 5th 2008 |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 22 | * -Modified CALLEE_REG save/restore macros to handle the fact that |
| 23 | * r25 contains the kernel current task ptr |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 24 | * - Defined Stack Switching Macro to be reused in all intr/excp hdlrs |
| 25 | * - Shaved off 11 instructions from RESTORE_ALL_INT1 by using the |
| 26 | * address Write back load ld.ab instead of seperate ld/add instn |
| 27 | * |
| 28 | * Amit Bhor, Sameer Dhavale: Codito Technologies 2004 |
| 29 | */ |
| 30 | |
| 31 | #ifndef __ASM_ARC_ENTRY_H |
| 32 | #define __ASM_ARC_ENTRY_H |
| 33 | |
| 34 | #ifdef __ASSEMBLY__ |
| 35 | #include <asm/unistd.h> /* For NR_syscalls defination */ |
| 36 | #include <asm/asm-offsets.h> |
| 37 | #include <asm/arcregs.h> |
| 38 | #include <asm/ptrace.h> |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 39 | #include <asm/processor.h> /* For VMALLOC_START */ |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 40 | #include <asm/thread_info.h> /* For THREAD_SIZE */ |
| 41 | |
| 42 | /* Note on the LD/ST addr modes with addr reg wback |
| 43 | * |
| 44 | * LD.a same as LD.aw |
| 45 | * |
| 46 | * LD.a reg1, [reg2, x] => Pre Incr |
| 47 | * Eff Addr for load = [reg2 + x] |
| 48 | * |
| 49 | * LD.ab reg1, [reg2, x] => Post Incr |
| 50 | * Eff Addr for load = [reg2] |
| 51 | */ |
| 52 | |
| 53 | /*-------------------------------------------------------------- |
| 54 | * Save caller saved registers (scratch registers) ( r0 - r12 ) |
| 55 | * Registers are pushed / popped in the order defined in struct ptregs |
| 56 | * in asm/ptrace.h |
| 57 | *-------------------------------------------------------------*/ |
| 58 | .macro SAVE_CALLER_SAVED |
| 59 | st.a r0, [sp, -4] |
| 60 | st.a r1, [sp, -4] |
| 61 | st.a r2, [sp, -4] |
| 62 | st.a r3, [sp, -4] |
| 63 | st.a r4, [sp, -4] |
| 64 | st.a r5, [sp, -4] |
| 65 | st.a r6, [sp, -4] |
| 66 | st.a r7, [sp, -4] |
| 67 | st.a r8, [sp, -4] |
| 68 | st.a r9, [sp, -4] |
| 69 | st.a r10, [sp, -4] |
| 70 | st.a r11, [sp, -4] |
| 71 | st.a r12, [sp, -4] |
| 72 | .endm |
| 73 | |
| 74 | /*-------------------------------------------------------------- |
| 75 | * Restore caller saved registers (scratch registers) |
| 76 | *-------------------------------------------------------------*/ |
| 77 | .macro RESTORE_CALLER_SAVED |
| 78 | ld.ab r12, [sp, 4] |
| 79 | ld.ab r11, [sp, 4] |
| 80 | ld.ab r10, [sp, 4] |
| 81 | ld.ab r9, [sp, 4] |
| 82 | ld.ab r8, [sp, 4] |
| 83 | ld.ab r7, [sp, 4] |
| 84 | ld.ab r6, [sp, 4] |
| 85 | ld.ab r5, [sp, 4] |
| 86 | ld.ab r4, [sp, 4] |
| 87 | ld.ab r3, [sp, 4] |
| 88 | ld.ab r2, [sp, 4] |
| 89 | ld.ab r1, [sp, 4] |
| 90 | ld.ab r0, [sp, 4] |
| 91 | .endm |
| 92 | |
| 93 | |
| 94 | /*-------------------------------------------------------------- |
| 95 | * Save callee saved registers (non scratch registers) ( r13 - r25 ) |
| 96 | * on kernel stack. |
| 97 | * User mode callee regs need to be saved in case of |
| 98 | * -fork and friends for replicating from parent to child |
| 99 | * -before going into do_signal( ) for ptrace/core-dump |
| 100 | * Special case handling is required for r25 in case it is used by kernel |
| 101 | * for caching task ptr. Low level exception/ISR save user mode r25 |
| 102 | * into task->thread.user_r25. So it needs to be retrieved from there and |
| 103 | * saved into kernel stack with rest of callee reg-file |
| 104 | *-------------------------------------------------------------*/ |
| 105 | .macro SAVE_CALLEE_SAVED_USER |
| 106 | st.a r13, [sp, -4] |
| 107 | st.a r14, [sp, -4] |
| 108 | st.a r15, [sp, -4] |
| 109 | st.a r16, [sp, -4] |
| 110 | st.a r17, [sp, -4] |
| 111 | st.a r18, [sp, -4] |
| 112 | st.a r19, [sp, -4] |
| 113 | st.a r20, [sp, -4] |
| 114 | st.a r21, [sp, -4] |
| 115 | st.a r22, [sp, -4] |
| 116 | st.a r23, [sp, -4] |
| 117 | st.a r24, [sp, -4] |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 118 | |
| 119 | #ifdef CONFIG_ARC_CURR_IN_REG |
| 120 | ; Retrieve orig r25 and save it on stack |
| 121 | ld r12, [r25, TASK_THREAD + THREAD_USER_R25] |
| 122 | st.a r12, [sp, -4] |
| 123 | #else |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 124 | st.a r25, [sp, -4] |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 125 | #endif |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 126 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 127 | .endm |
| 128 | |
| 129 | /*-------------------------------------------------------------- |
| 130 | * Save callee saved registers (non scratch registers) ( r13 - r25 ) |
| 131 | * kernel mode callee regs needed to be saved in case of context switch |
| 132 | * If r25 is used for caching task pointer then that need not be saved |
| 133 | * as it can be re-created from current task global |
| 134 | *-------------------------------------------------------------*/ |
| 135 | .macro SAVE_CALLEE_SAVED_KERNEL |
| 136 | st.a r13, [sp, -4] |
| 137 | st.a r14, [sp, -4] |
| 138 | st.a r15, [sp, -4] |
| 139 | st.a r16, [sp, -4] |
| 140 | st.a r17, [sp, -4] |
| 141 | st.a r18, [sp, -4] |
| 142 | st.a r19, [sp, -4] |
| 143 | st.a r20, [sp, -4] |
| 144 | st.a r21, [sp, -4] |
| 145 | st.a r22, [sp, -4] |
| 146 | st.a r23, [sp, -4] |
| 147 | st.a r24, [sp, -4] |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 148 | #ifdef CONFIG_ARC_CURR_IN_REG |
Vineet Gupta | 16f9afe | 2013-05-27 21:43:41 +0530 | [diff] [blame^] | 149 | sub sp, sp, 4 |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 150 | #else |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 151 | st.a r25, [sp, -4] |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 152 | #endif |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 153 | .endm |
| 154 | |
| 155 | /*-------------------------------------------------------------- |
| 156 | * RESTORE_CALLEE_SAVED_KERNEL: |
| 157 | * Loads callee (non scratch) Reg File by popping from Kernel mode stack. |
| 158 | * This is reverse of SAVE_CALLEE_SAVED, |
| 159 | * |
| 160 | * NOTE: |
| 161 | * Ideally this shd only be called in switch_to for loading |
| 162 | * switched-IN task's CALLEE Reg File. |
| 163 | * For all other cases RESTORE_CALLEE_SAVED_FAST must be used |
| 164 | * which simply pops the stack w/o touching regs. |
| 165 | *-------------------------------------------------------------*/ |
| 166 | .macro RESTORE_CALLEE_SAVED_KERNEL |
| 167 | |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 168 | #ifdef CONFIG_ARC_CURR_IN_REG |
Vineet Gupta | 16f9afe | 2013-05-27 21:43:41 +0530 | [diff] [blame^] | 169 | add sp, sp, 4 /* skip usual r25 placeholder */ |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 170 | #else |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 171 | ld.ab r25, [sp, 4] |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 172 | #endif |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 173 | ld.ab r24, [sp, 4] |
| 174 | ld.ab r23, [sp, 4] |
| 175 | ld.ab r22, [sp, 4] |
| 176 | ld.ab r21, [sp, 4] |
| 177 | ld.ab r20, [sp, 4] |
| 178 | ld.ab r19, [sp, 4] |
| 179 | ld.ab r18, [sp, 4] |
| 180 | ld.ab r17, [sp, 4] |
| 181 | ld.ab r16, [sp, 4] |
| 182 | ld.ab r15, [sp, 4] |
| 183 | ld.ab r14, [sp, 4] |
| 184 | ld.ab r13, [sp, 4] |
| 185 | |
| 186 | .endm |
| 187 | |
| 188 | /*-------------------------------------------------------------- |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 189 | * RESTORE_CALLEE_SAVED_USER: |
| 190 | * This is called after do_signal where tracer might have changed callee regs |
| 191 | * thus we need to restore the reg file. |
| 192 | * Special case handling is required for r25 in case it is used by kernel |
| 193 | * for caching task ptr. Ptrace would have modified on-kernel-stack value of |
| 194 | * r25, which needs to be shoved back into task->thread.user_r25 where from |
| 195 | * Low level exception/ISR return code will retrieve to populate with rest of |
| 196 | * callee reg-file. |
| 197 | *-------------------------------------------------------------*/ |
| 198 | .macro RESTORE_CALLEE_SAVED_USER |
| 199 | |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 200 | #ifdef CONFIG_ARC_CURR_IN_REG |
| 201 | ld.ab r12, [sp, 4] |
| 202 | st r12, [r25, TASK_THREAD + THREAD_USER_R25] |
| 203 | #else |
| 204 | ld.ab r25, [sp, 4] |
| 205 | #endif |
| 206 | |
| 207 | ld.ab r24, [sp, 4] |
| 208 | ld.ab r23, [sp, 4] |
| 209 | ld.ab r22, [sp, 4] |
| 210 | ld.ab r21, [sp, 4] |
| 211 | ld.ab r20, [sp, 4] |
| 212 | ld.ab r19, [sp, 4] |
| 213 | ld.ab r18, [sp, 4] |
| 214 | ld.ab r17, [sp, 4] |
| 215 | ld.ab r16, [sp, 4] |
| 216 | ld.ab r15, [sp, 4] |
| 217 | ld.ab r14, [sp, 4] |
| 218 | ld.ab r13, [sp, 4] |
| 219 | .endm |
| 220 | |
| 221 | /*-------------------------------------------------------------- |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 222 | * Super FAST Restore callee saved regs by simply re-adjusting SP |
| 223 | *-------------------------------------------------------------*/ |
| 224 | .macro DISCARD_CALLEE_SAVED_USER |
Vineet Gupta | 16f9afe | 2013-05-27 21:43:41 +0530 | [diff] [blame^] | 225 | add sp, sp, SZ_CALLEE_REGS |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 226 | .endm |
| 227 | |
| 228 | /*-------------------------------------------------------------- |
| 229 | * Restore User mode r25 saved in task_struct->thread.user_r25 |
| 230 | *-------------------------------------------------------------*/ |
| 231 | .macro RESTORE_USER_R25 |
| 232 | ld r25, [r25, TASK_THREAD + THREAD_USER_R25] |
| 233 | .endm |
| 234 | |
| 235 | /*------------------------------------------------------------- |
| 236 | * given a tsk struct, get to the base of it's kernel mode stack |
| 237 | * tsk->thread_info is really a PAGE, whose bottom hoists stack |
| 238 | * which grows upwards towards thread_info |
| 239 | *------------------------------------------------------------*/ |
| 240 | |
| 241 | .macro GET_TSK_STACK_BASE tsk, out |
| 242 | |
| 243 | /* Get task->thread_info (this is essentially start of a PAGE) */ |
| 244 | ld \out, [\tsk, TASK_THREAD_INFO] |
| 245 | |
| 246 | /* Go to end of page where stack begins (grows upwards) */ |
Vineet Gupta | 283237a | 2013-05-28 09:34:45 +0530 | [diff] [blame] | 247 | add2 \out, \out, (THREAD_SIZE)/4 |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 248 | |
| 249 | .endm |
| 250 | |
| 251 | /*-------------------------------------------------------------- |
| 252 | * Switch to Kernel Mode stack if SP points to User Mode stack |
| 253 | * |
| 254 | * Entry : r9 contains pre-IRQ/exception/trap status32 |
| 255 | * Exit : SP is set to kernel mode stack pointer |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 256 | * If CURR_IN_REG, r25 set to "current" task pointer |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 257 | * Clobbers: r9 |
| 258 | *-------------------------------------------------------------*/ |
| 259 | |
| 260 | .macro SWITCH_TO_KERNEL_STK |
| 261 | |
| 262 | /* User Mode when this happened ? Yes: Proceed to switch stack */ |
| 263 | bbit1 r9, STATUS_U_BIT, 88f |
| 264 | |
| 265 | /* OK we were already in kernel mode when this event happened, thus can |
| 266 | * assume SP is kernel mode SP. _NO_ need to do any stack switching |
| 267 | */ |
| 268 | |
Vineet Gupta | 4788a59 | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 269 | #ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS |
| 270 | /* However.... |
| 271 | * If Level 2 Interrupts enabled, we may end up with a corner case: |
| 272 | * 1. User Task executing |
| 273 | * 2. L1 IRQ taken, ISR starts (CPU auto-switched to KERNEL mode) |
| 274 | * 3. But before it could switch SP from USER to KERNEL stack |
| 275 | * a L2 IRQ "Interrupts" L1 |
| 276 | * Thay way although L2 IRQ happened in Kernel mode, stack is still |
| 277 | * not switched. |
| 278 | * To handle this, we may need to switch stack even if in kernel mode |
| 279 | * provided SP has values in range of USER mode stack ( < 0x7000_0000 ) |
| 280 | */ |
| 281 | brlo sp, VMALLOC_START, 88f |
| 282 | |
| 283 | /* TODO: vineetg: |
| 284 | * We need to be a bit more cautious here. What if a kernel bug in |
| 285 | * L1 ISR, caused SP to go whaco (some small value which looks like |
| 286 | * USER stk) and then we take L2 ISR. |
| 287 | * Above brlo alone would treat it as a valid L1-L2 sceanrio |
| 288 | * instead of shouting alound |
| 289 | * The only feasible way is to make sure this L2 happened in |
| 290 | * L1 prelogue ONLY i.e. ilink2 is less than a pre-set marker in |
| 291 | * L1 ISR before it switches stack |
| 292 | */ |
| 293 | |
| 294 | #endif |
| 295 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 296 | /* Save Pre Intr/Exception KERNEL MODE SP on kernel stack |
| 297 | * safe-keeping not really needed, but it keeps the epilogue code |
| 298 | * (SP restore) simpler/uniform. |
| 299 | */ |
| 300 | b.d 77f |
| 301 | |
| 302 | st.a sp, [sp, -12] ; Make room for orig_r0 and orig_r8 |
| 303 | |
| 304 | 88: /*------Intr/Ecxp happened in user mode, "switch" stack ------ */ |
| 305 | |
| 306 | GET_CURR_TASK_ON_CPU r9 |
| 307 | |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 308 | #ifdef CONFIG_ARC_CURR_IN_REG |
| 309 | |
| 310 | /* If current task pointer cached in r25, time to |
| 311 | * -safekeep USER r25 in task->thread_struct->user_r25 |
| 312 | * -load r25 with current task ptr |
| 313 | */ |
| 314 | st.as r25, [r9, (TASK_THREAD + THREAD_USER_R25)/4] |
| 315 | mov r25, r9 |
| 316 | #endif |
| 317 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 318 | /* With current tsk in r9, get it's kernel mode stack base */ |
| 319 | GET_TSK_STACK_BASE r9, r9 |
| 320 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 321 | /* Save Pre Intr/Exception User SP on kernel stack */ |
| 322 | st.a sp, [r9, -12] ; Make room for orig_r0 and orig_r8 |
| 323 | |
| 324 | /* CAUTION: |
| 325 | * SP should be set at the very end when we are done with everything |
| 326 | * In case of 2 levels of interrupt we depend on value of SP to assume |
| 327 | * that everything else is done (loading r25 etc) |
| 328 | */ |
| 329 | |
| 330 | /* set SP to point to kernel mode stack */ |
| 331 | mov sp, r9 |
| 332 | |
| 333 | 77: /* ----- Stack Switched to kernel Mode, Now save REG FILE ----- */ |
| 334 | |
| 335 | .endm |
| 336 | |
| 337 | /*------------------------------------------------------------ |
| 338 | * "FAKE" a rtie to return from CPU Exception context |
| 339 | * This is to re-enable Exceptions within exception |
| 340 | * Look at EV_ProtV to see how this is actually used |
| 341 | *-------------------------------------------------------------*/ |
| 342 | |
| 343 | .macro FAKE_RET_FROM_EXCPN reg |
| 344 | |
| 345 | ld \reg, [sp, PT_status32] |
| 346 | bic \reg, \reg, (STATUS_U_MASK|STATUS_DE_MASK) |
| 347 | bset \reg, \reg, STATUS_L_BIT |
| 348 | sr \reg, [erstatus] |
| 349 | mov \reg, 55f |
| 350 | sr \reg, [eret] |
| 351 | |
| 352 | rtie |
| 353 | 55: |
| 354 | .endm |
| 355 | |
| 356 | /* |
| 357 | * @reg [OUT] &thread_info of "current" |
| 358 | */ |
| 359 | .macro GET_CURR_THR_INFO_FROM_SP reg |
| 360 | and \reg, sp, ~(THREAD_SIZE - 1) |
| 361 | .endm |
| 362 | |
| 363 | /* |
| 364 | * @reg [OUT] thread_info->flags of "current" |
| 365 | */ |
| 366 | .macro GET_CURR_THR_INFO_FLAGS reg |
| 367 | GET_CURR_THR_INFO_FROM_SP \reg |
| 368 | ld \reg, [\reg, THREAD_INFO_FLAGS] |
| 369 | .endm |
| 370 | |
| 371 | /*-------------------------------------------------------------- |
| 372 | * For early Exception Prologue, a core reg is temporarily needed to |
| 373 | * code the rest of prolog (stack switching). This is done by stashing |
| 374 | * it to memory (non-SMP case) or SCRATCH0 Aux Reg (SMP). |
| 375 | * |
| 376 | * Before saving the full regfile - this reg is restored back, only |
| 377 | * to be saved again on kernel mode stack, as part of ptregs. |
| 378 | *-------------------------------------------------------------*/ |
| 379 | .macro EXCPN_PROLOG_FREEUP_REG reg |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 380 | #ifdef CONFIG_SMP |
| 381 | sr \reg, [ARC_REG_SCRATCH_DATA0] |
| 382 | #else |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 383 | st \reg, [@ex_saved_reg1] |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 384 | #endif |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 385 | .endm |
| 386 | |
| 387 | .macro EXCPN_PROLOG_RESTORE_REG reg |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 388 | #ifdef CONFIG_SMP |
| 389 | lr \reg, [ARC_REG_SCRATCH_DATA0] |
| 390 | #else |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 391 | ld \reg, [@ex_saved_reg1] |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 392 | #endif |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 393 | .endm |
| 394 | |
| 395 | /*-------------------------------------------------------------- |
| 396 | * Save all registers used by Exceptions (TLB Miss, Prot-V, Mem err etc) |
| 397 | * Requires SP to be already switched to kernel mode Stack |
| 398 | * sp points to the next free element on the stack at exit of this macro. |
| 399 | * Registers are pushed / popped in the order defined in struct ptregs |
| 400 | * in asm/ptrace.h |
| 401 | * Note that syscalls are implemented via TRAP which is also a exception |
| 402 | * from CPU's point of view |
| 403 | *-------------------------------------------------------------*/ |
| 404 | .macro SAVE_ALL_EXCEPTION marker |
| 405 | |
Vineet Gupta | 367f3fc | 2013-03-20 16:53:14 +0530 | [diff] [blame] | 406 | st \marker, [sp, 8] /* orig_r8 */ |
Vineet Gupta | 5c39c0a | 2013-02-11 20:01:24 +0530 | [diff] [blame] | 407 | st r0, [sp, 4] /* orig_r0, needed only for sys calls */ |
| 408 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 409 | /* Restore r9 used to code the early prologue */ |
| 410 | EXCPN_PROLOG_RESTORE_REG r9 |
| 411 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 412 | SAVE_CALLER_SAVED |
| 413 | st.a r26, [sp, -4] /* gp */ |
| 414 | st.a fp, [sp, -4] |
| 415 | st.a blink, [sp, -4] |
| 416 | lr r9, [eret] |
| 417 | st.a r9, [sp, -4] |
| 418 | lr r9, [erstatus] |
| 419 | st.a r9, [sp, -4] |
| 420 | st.a lp_count, [sp, -4] |
| 421 | lr r9, [lp_end] |
| 422 | st.a r9, [sp, -4] |
| 423 | lr r9, [lp_start] |
| 424 | st.a r9, [sp, -4] |
| 425 | lr r9, [erbta] |
| 426 | st.a r9, [sp, -4] |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 427 | .endm |
| 428 | |
| 429 | /*-------------------------------------------------------------- |
| 430 | * Save scratch regs for exceptions |
| 431 | *-------------------------------------------------------------*/ |
| 432 | .macro SAVE_ALL_SYS |
Vineet Gupta | 5c39c0a | 2013-02-11 20:01:24 +0530 | [diff] [blame] | 433 | SAVE_ALL_EXCEPTION orig_r8_IS_EXCPN |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 434 | .endm |
| 435 | |
| 436 | /*-------------------------------------------------------------- |
| 437 | * Save scratch regs for sys calls |
| 438 | *-------------------------------------------------------------*/ |
| 439 | .macro SAVE_ALL_TRAP |
Vineet Gupta | 5c39c0a | 2013-02-11 20:01:24 +0530 | [diff] [blame] | 440 | /* |
| 441 | * Setup pt_regs->orig_r8. |
| 442 | * Encode syscall number (r8) in upper short word of event type (r9) |
| 443 | * N.B. #1: This is already endian safe (see ptrace.h) |
| 444 | * #2: Only r9 can be used as scratch as it is already clobbered |
| 445 | * and it's contents are no longer needed by the latter part |
| 446 | * of exception prologue |
| 447 | */ |
| 448 | lsl r9, r8, 16 |
| 449 | or r9, r9, orig_r8_IS_SCALL |
| 450 | |
| 451 | SAVE_ALL_EXCEPTION r9 |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 452 | .endm |
| 453 | |
| 454 | /*-------------------------------------------------------------- |
| 455 | * Restore all registers used by system call or Exceptions |
| 456 | * SP should always be pointing to the next free stack element |
| 457 | * when entering this macro. |
| 458 | * |
| 459 | * NOTE: |
| 460 | * |
| 461 | * It is recommended that lp_count/ilink1/ilink2 not be used as a dest reg |
| 462 | * for memory load operations. If used in that way interrupts are deffered |
| 463 | * by hardware and that is not good. |
| 464 | *-------------------------------------------------------------*/ |
| 465 | .macro RESTORE_ALL_SYS |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 466 | ld.ab r9, [sp, 4] |
| 467 | sr r9, [erbta] |
| 468 | ld.ab r9, [sp, 4] |
| 469 | sr r9, [lp_start] |
| 470 | ld.ab r9, [sp, 4] |
| 471 | sr r9, [lp_end] |
| 472 | ld.ab r9, [sp, 4] |
| 473 | mov lp_count, r9 |
| 474 | ld.ab r9, [sp, 4] |
| 475 | sr r9, [erstatus] |
| 476 | ld.ab r9, [sp, 4] |
| 477 | sr r9, [eret] |
| 478 | ld.ab blink, [sp, 4] |
| 479 | ld.ab fp, [sp, 4] |
| 480 | ld.ab r26, [sp, 4] /* gp */ |
| 481 | RESTORE_CALLER_SAVED |
| 482 | |
| 483 | ld sp, [sp] /* restore original sp */ |
| 484 | /* orig_r0 and orig_r8 skipped automatically */ |
| 485 | .endm |
| 486 | |
| 487 | |
| 488 | /*-------------------------------------------------------------- |
| 489 | * Save all registers used by interrupt handlers. |
| 490 | *-------------------------------------------------------------*/ |
| 491 | .macro SAVE_ALL_INT1 |
| 492 | |
| 493 | /* restore original r9 , saved in int1_saved_reg |
| 494 | * It will be saved on stack in macro: SAVE_CALLER_SAVED |
| 495 | */ |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 496 | #ifdef CONFIG_SMP |
| 497 | lr r9, [ARC_REG_SCRATCH_DATA0] |
| 498 | #else |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 499 | ld r9, [@int1_saved_reg] |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 500 | #endif |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 501 | |
| 502 | /* now we are ready to save the remaining context :) */ |
Vineet Gupta | 5c39c0a | 2013-02-11 20:01:24 +0530 | [diff] [blame] | 503 | st orig_r8_IS_IRQ1, [sp, 8] /* Event Type */ |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 504 | st 0, [sp, 4] /* orig_r0 , N/A for IRQ */ |
| 505 | SAVE_CALLER_SAVED |
| 506 | st.a r26, [sp, -4] /* gp */ |
| 507 | st.a fp, [sp, -4] |
| 508 | st.a blink, [sp, -4] |
| 509 | st.a ilink1, [sp, -4] |
| 510 | lr r9, [status32_l1] |
| 511 | st.a r9, [sp, -4] |
| 512 | st.a lp_count, [sp, -4] |
| 513 | lr r9, [lp_end] |
| 514 | st.a r9, [sp, -4] |
| 515 | lr r9, [lp_start] |
| 516 | st.a r9, [sp, -4] |
| 517 | lr r9, [bta_l1] |
| 518 | st.a r9, [sp, -4] |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 519 | .endm |
| 520 | |
Vineet Gupta | 4788a59 | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 521 | .macro SAVE_ALL_INT2 |
| 522 | |
| 523 | /* TODO-vineetg: SMP we can't use global nor can we use |
| 524 | * SCRATCH0 as we do for int1 because while int1 is using |
| 525 | * it, int2 can come |
| 526 | */ |
| 527 | /* retsore original r9 , saved in sys_saved_r9 */ |
| 528 | ld r9, [@int2_saved_reg] |
| 529 | |
| 530 | /* now we are ready to save the remaining context :) */ |
| 531 | st orig_r8_IS_IRQ2, [sp, 8] /* Event Type */ |
| 532 | st 0, [sp, 4] /* orig_r0 , N/A for IRQ */ |
| 533 | SAVE_CALLER_SAVED |
| 534 | st.a r26, [sp, -4] /* gp */ |
| 535 | st.a fp, [sp, -4] |
| 536 | st.a blink, [sp, -4] |
| 537 | st.a ilink2, [sp, -4] |
| 538 | lr r9, [status32_l2] |
| 539 | st.a r9, [sp, -4] |
| 540 | st.a lp_count, [sp, -4] |
| 541 | lr r9, [lp_end] |
| 542 | st.a r9, [sp, -4] |
| 543 | lr r9, [lp_start] |
| 544 | st.a r9, [sp, -4] |
| 545 | lr r9, [bta_l2] |
| 546 | st.a r9, [sp, -4] |
Vineet Gupta | 4788a59 | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 547 | .endm |
| 548 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 549 | /*-------------------------------------------------------------- |
| 550 | * Restore all registers used by interrupt handlers. |
| 551 | * |
| 552 | * NOTE: |
| 553 | * |
| 554 | * It is recommended that lp_count/ilink1/ilink2 not be used as a dest reg |
| 555 | * for memory load operations. If used in that way interrupts are deffered |
| 556 | * by hardware and that is not good. |
| 557 | *-------------------------------------------------------------*/ |
| 558 | |
| 559 | .macro RESTORE_ALL_INT1 |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 560 | ld.ab r9, [sp, 4] /* Actual reg file */ |
| 561 | sr r9, [bta_l1] |
| 562 | ld.ab r9, [sp, 4] |
| 563 | sr r9, [lp_start] |
| 564 | ld.ab r9, [sp, 4] |
| 565 | sr r9, [lp_end] |
| 566 | ld.ab r9, [sp, 4] |
| 567 | mov lp_count, r9 |
| 568 | ld.ab r9, [sp, 4] |
| 569 | sr r9, [status32_l1] |
| 570 | ld.ab r9, [sp, 4] |
| 571 | mov ilink1, r9 |
| 572 | ld.ab blink, [sp, 4] |
| 573 | ld.ab fp, [sp, 4] |
| 574 | ld.ab r26, [sp, 4] /* gp */ |
| 575 | RESTORE_CALLER_SAVED |
| 576 | |
| 577 | ld sp, [sp] /* restore original sp */ |
| 578 | /* orig_r0 and orig_r8 skipped automatically */ |
| 579 | .endm |
| 580 | |
Vineet Gupta | 4788a59 | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 581 | .macro RESTORE_ALL_INT2 |
Vineet Gupta | 4788a59 | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 582 | ld.ab r9, [sp, 4] |
| 583 | sr r9, [bta_l2] |
| 584 | ld.ab r9, [sp, 4] |
| 585 | sr r9, [lp_start] |
| 586 | ld.ab r9, [sp, 4] |
| 587 | sr r9, [lp_end] |
| 588 | ld.ab r9, [sp, 4] |
| 589 | mov lp_count, r9 |
| 590 | ld.ab r9, [sp, 4] |
| 591 | sr r9, [status32_l2] |
| 592 | ld.ab r9, [sp, 4] |
| 593 | mov ilink2, r9 |
| 594 | ld.ab blink, [sp, 4] |
| 595 | ld.ab fp, [sp, 4] |
| 596 | ld.ab r26, [sp, 4] /* gp */ |
| 597 | RESTORE_CALLER_SAVED |
| 598 | |
| 599 | ld sp, [sp] /* restore original sp */ |
| 600 | /* orig_r0 and orig_r8 skipped automatically */ |
| 601 | |
| 602 | .endm |
| 603 | |
| 604 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 605 | /* Get CPU-ID of this core */ |
| 606 | .macro GET_CPU_ID reg |
| 607 | lr \reg, [identity] |
| 608 | lsr \reg, \reg, 8 |
| 609 | bmsk \reg, \reg, 7 |
| 610 | .endm |
| 611 | |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 612 | #ifdef CONFIG_SMP |
| 613 | |
| 614 | /*------------------------------------------------- |
| 615 | * Retrieve the current running task on this CPU |
| 616 | * 1. Determine curr CPU id. |
| 617 | * 2. Use it to index into _current_task[ ] |
| 618 | */ |
| 619 | .macro GET_CURR_TASK_ON_CPU reg |
| 620 | GET_CPU_ID \reg |
| 621 | ld.as \reg, [@_current_task, \reg] |
| 622 | .endm |
| 623 | |
| 624 | /*------------------------------------------------- |
| 625 | * Save a new task as the "current" task on this CPU |
| 626 | * 1. Determine curr CPU id. |
| 627 | * 2. Use it to index into _current_task[ ] |
| 628 | * |
| 629 | * Coded differently than GET_CURR_TASK_ON_CPU (which uses LD.AS) |
| 630 | * because ST r0, [r1, offset] can ONLY have s9 @offset |
| 631 | * while LD can take s9 (4 byte insn) or LIMM (8 byte insn) |
| 632 | */ |
| 633 | |
| 634 | .macro SET_CURR_TASK_ON_CPU tsk, tmp |
| 635 | GET_CPU_ID \tmp |
| 636 | add2 \tmp, @_current_task, \tmp |
| 637 | st \tsk, [\tmp] |
| 638 | #ifdef CONFIG_ARC_CURR_IN_REG |
| 639 | mov r25, \tsk |
| 640 | #endif |
| 641 | |
| 642 | .endm |
| 643 | |
| 644 | |
| 645 | #else /* Uniprocessor implementation of macros */ |
| 646 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 647 | .macro GET_CURR_TASK_ON_CPU reg |
| 648 | ld \reg, [@_current_task] |
| 649 | .endm |
| 650 | |
| 651 | .macro SET_CURR_TASK_ON_CPU tsk, tmp |
| 652 | st \tsk, [@_current_task] |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 653 | #ifdef CONFIG_ARC_CURR_IN_REG |
| 654 | mov r25, \tsk |
| 655 | #endif |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 656 | .endm |
| 657 | |
Vineet Gupta | 41195d2 | 2013-01-18 15:12:23 +0530 | [diff] [blame] | 658 | #endif /* SMP / UNI */ |
| 659 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 660 | /* ------------------------------------------------------------------ |
| 661 | * Get the ptr to some field of Current Task at @off in task struct |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 662 | * -Uses r25 for Current task ptr if that is enabled |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 663 | */ |
| 664 | |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 665 | #ifdef CONFIG_ARC_CURR_IN_REG |
| 666 | |
| 667 | .macro GET_CURR_TASK_FIELD_PTR off, reg |
| 668 | add \reg, r25, \off |
| 669 | .endm |
| 670 | |
| 671 | #else |
| 672 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 673 | .macro GET_CURR_TASK_FIELD_PTR off, reg |
| 674 | GET_CURR_TASK_ON_CPU \reg |
| 675 | add \reg, \reg, \off |
| 676 | .endm |
| 677 | |
Vineet Gupta | 080c374 | 2013-02-11 19:52:57 +0530 | [diff] [blame] | 678 | #endif /* CONFIG_ARC_CURR_IN_REG */ |
| 679 | |
Vineet Gupta | 9d42c84 | 2013-01-18 15:12:18 +0530 | [diff] [blame] | 680 | #endif /* __ASSEMBLY__ */ |
| 681 | |
| 682 | #endif /* __ASM_ARC_ENTRY_H */ |