1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __HEAD_32_H__ 3 #define __HEAD_32_H__ 4 5 #include <asm/ptrace.h> /* for STACK_FRAME_REGS_MARKER */ 6 7 /* 8 * Exception entry code. This code runs with address translation 9 * turned off, i.e. using physical addresses. 10 * We assume sprg3 has the physical address of the current 11 * task's thread_struct. 12 */ 13 .macro EXCEPTION_PROLOG handle_dar_dsisr=0 14 EXCEPTION_PROLOG_0 handle_dar_dsisr=\handle_dar_dsisr 15 EXCEPTION_PROLOG_1 16 EXCEPTION_PROLOG_2 handle_dar_dsisr=\handle_dar_dsisr 17 .endm 18 19 .macro EXCEPTION_PROLOG_0 handle_dar_dsisr=0 20 mtspr SPRN_SPRG_SCRATCH0,r10 21 mtspr SPRN_SPRG_SCRATCH1,r11 22 #ifdef CONFIG_VMAP_STACK 23 mfspr r10, SPRN_SPRG_THREAD 24 .if \handle_dar_dsisr 25 mfspr r11, SPRN_DAR 26 stw r11, DAR(r10) 27 mfspr r11, SPRN_DSISR 28 stw r11, DSISR(r10) 29 .endif 30 mfspr r11, SPRN_SRR0 31 stw r11, SRR0(r10) 32 #endif 33 mfspr r11, SPRN_SRR1 /* check whether user or kernel */ 34 #ifdef CONFIG_VMAP_STACK 35 stw r11, SRR1(r10) 36 #endif 37 mfcr r10 38 andi. r11, r11, MSR_PR 39 .endm 40 41 .macro EXCEPTION_PROLOG_1 for_rtas=0 42 #ifdef CONFIG_VMAP_STACK 43 mtspr SPRN_SPRG_SCRATCH2,r1 44 subi r1, r1, INT_FRAME_SIZE /* use r1 if kernel */ 45 beq 1f 46 mfspr r1,SPRN_SPRG_THREAD 47 lwz r1,TASK_STACK-THREAD(r1) 48 addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE 49 1: 50 mtcrf 0x7f, r1 51 bt 32 - THREAD_ALIGN_SHIFT, stack_overflow 52 #else 53 subi r11, r1, INT_FRAME_SIZE /* use r1 if kernel */ 54 beq 1f 55 mfspr r11,SPRN_SPRG_THREAD 56 lwz r11,TASK_STACK-THREAD(r11) 57 addi r11, r11, THREAD_SIZE - INT_FRAME_SIZE 58 1: tophys(r11, r11) 59 #endif 60 .endm 61 62 .macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0 63 #ifdef CONFIG_VMAP_STACK 64 li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ 65 mtmsr r11 66 isync 67 mfspr r11, SPRN_SPRG_SCRATCH2 68 stw r11,GPR1(r1) 69 stw r11,0(r1) 70 mr r11, r1 71 #else 72 stw r1,GPR1(r11) 73 stw r1,0(r11) 74 tovirt(r1, r11) /* set new kernel sp */ 75 #endif 76 stw r10,_CCR(r11) /* save registers */ 77 stw r12,GPR12(r11) 78 stw r9,GPR9(r11) 79 mfspr r10,SPRN_SPRG_SCRATCH0 80 mfspr r12,SPRN_SPRG_SCRATCH1 81 stw r10,GPR10(r11) 82 stw r12,GPR11(r11) 83 mflr r10 84 stw r10,_LINK(r11) 85 #ifdef CONFIG_VMAP_STACK 86 mfspr r12, SPRN_SPRG_THREAD 87 tovirt(r12, r12) 88 .if \handle_dar_dsisr 89 lwz r10, DAR(r12) 90 stw r10, _DAR(r11) 91 lwz r10, DSISR(r12) 92 stw r10, _DSISR(r11) 93 .endif 94 lwz r9, SRR1(r12) 95 lwz r12, SRR0(r12) 96 #else 97 mfspr r12,SPRN_SRR0 98 mfspr r9,SPRN_SRR1 99 #endif 100 #ifdef CONFIG_40x 101 rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */ 102 #else 103 #ifdef CONFIG_VMAP_STACK 104 li r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */ 105 #else 106 li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR) /* can take exceptions */ 107 #endif 108 mtmsr r10 /* (except for mach check in rtas) */ 109 #endif 110 stw r0,GPR0(r11) 111 lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */ 112 addi r10,r10,STACK_FRAME_REGS_MARKER@l 113 stw r10,8(r11) 114 SAVE_4GPRS(3, r11) 115 SAVE_2GPRS(7, r11) 116 .endm 117 118 .macro SYSCALL_ENTRY trapno 119 mfspr r12,SPRN_SPRG_THREAD 120 mfspr r9, SPRN_SRR1 121 #ifdef CONFIG_VMAP_STACK 122 mfspr r11, SPRN_SRR0 123 mtctr r11 124 #endif 125 andi. r11, r9, MSR_PR 126 lwz r11,TASK_STACK-THREAD(r12) 127 beq- 99f 128 addi r11, r11, THREAD_SIZE - INT_FRAME_SIZE 129 #ifdef CONFIG_VMAP_STACK 130 li r10, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ 131 mtmsr r10 132 isync 133 #endif 134 tovirt_vmstack r12, r12 135 tophys_novmstack r11, r11 136 mflr r10 137 stw r10, _LINK(r11) 138 #ifdef CONFIG_VMAP_STACK 139 mfctr r10 140 #else 141 mfspr r10,SPRN_SRR0 142 #endif 143 stw r1,GPR1(r11) 144 stw r1,0(r11) 145 tovirt_novmstack r1, r11 /* set new kernel sp */ 146 stw r10,_NIP(r11) 147 mfcr r10 148 rlwinm r10,r10,0,4,2 /* Clear SO bit in CR */ 149 stw r10,_CCR(r11) /* save registers */ 150 #ifdef CONFIG_40x 151 rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */ 152 #else 153 #ifdef CONFIG_VMAP_STACK 154 LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~MSR_IR) /* can take exceptions */ 155 #else 156 LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~(MSR_IR|MSR_DR)) /* can take exceptions */ 157 #endif 158 mtmsr r10 /* (except for mach check in rtas) */ 159 #endif 160 lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */ 161 stw r2,GPR2(r11) 162 addi r10,r10,STACK_FRAME_REGS_MARKER@l 163 stw r9,_MSR(r11) 164 li r2, \trapno + 1 165 stw r10,8(r11) 166 stw r2,_TRAP(r11) 167 SAVE_GPR(0, r11) 168 SAVE_4GPRS(3, r11) 169 SAVE_2GPRS(7, r11) 170 addi r11,r1,STACK_FRAME_OVERHEAD 171 addi r2,r12,-THREAD 172 stw r11,PT_REGS(r12) 173 #if defined(CONFIG_40x) 174 /* Check to see if the dbcr0 register is set up to debug. Use the 175 internal debug mode bit to do this. */ 176 lwz r12,THREAD_DBCR0(r12) 177 andis. r12,r12,DBCR0_IDM@h 178 #endif 179 ACCOUNT_CPU_USER_ENTRY(r2, r11, r12) 180 #if defined(CONFIG_40x) 181 beq+ 3f 182 /* From user and task is ptraced - load up global dbcr0 */ 183 li r12,-1 /* clear all pending debug events */ 184 mtspr SPRN_DBSR,r12 185 lis r11,global_dbcr0@ha 186 tophys(r11,r11) 187 addi r11,r11,global_dbcr0@l 188 lwz r12,0(r11) 189 mtspr SPRN_DBCR0,r12 190 lwz r12,4(r11) 191 addi r12,r12,-1 192 stw r12,4(r11) 193 #endif 194 195 3: 196 tovirt_novmstack r2, r2 /* set r2 to current */ 197 lis r11, transfer_to_syscall@h 198 ori r11, r11, transfer_to_syscall@l 199 #ifdef CONFIG_TRACE_IRQFLAGS 200 /* 201 * If MSR is changing we need to keep interrupts disabled at this point 202 * otherwise we might risk taking an interrupt before we tell lockdep 203 * they are enabled. 204 */ 205 LOAD_REG_IMMEDIATE(r10, MSR_KERNEL) 206 rlwimi r10, r9, 0, MSR_EE 207 #else 208 LOAD_REG_IMMEDIATE(r10, MSR_KERNEL | MSR_EE) 209 #endif 210 #if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS) 211 mtspr SPRN_NRI, r0 212 #endif 213 mtspr SPRN_SRR1,r10 214 mtspr SPRN_SRR0,r11 215 rfi /* jump to handler, enable MMU */ 216 #ifdef CONFIG_40x 217 b . /* Prevent prefetch past rfi */ 218 #endif 219 99: b ret_from_kernel_syscall 220 .endm 221 222 .macro save_dar_dsisr_on_stack reg1, reg2, sp 223 #ifndef CONFIG_VMAP_STACK 224 mfspr \reg1, SPRN_DAR 225 mfspr \reg2, SPRN_DSISR 226 stw \reg1, _DAR(\sp) 227 stw \reg2, _DSISR(\sp) 228 #endif 229 .endm 230 231 .macro get_and_save_dar_dsisr_on_stack reg1, reg2, sp 232 #ifdef CONFIG_VMAP_STACK 233 lwz \reg1, _DAR(\sp) 234 lwz \reg2, _DSISR(\sp) 235 #else 236 save_dar_dsisr_on_stack \reg1, \reg2, \sp 237 #endif 238 .endm 239 240 .macro tovirt_vmstack dst, src 241 #ifdef CONFIG_VMAP_STACK 242 tovirt(\dst, \src) 243 #else 244 .ifnc \dst, \src 245 mr \dst, \src 246 .endif 247 #endif 248 .endm 249 250 .macro tovirt_novmstack dst, src 251 #ifndef CONFIG_VMAP_STACK 252 tovirt(\dst, \src) 253 #else 254 .ifnc \dst, \src 255 mr \dst, \src 256 .endif 257 #endif 258 .endm 259 260 .macro tophys_novmstack dst, src 261 #ifndef CONFIG_VMAP_STACK 262 tophys(\dst, \src) 263 #else 264 .ifnc \dst, \src 265 mr \dst, \src 266 .endif 267 #endif 268 .endm 269 270 /* 271 * Note: code which follows this uses cr0.eq (set if from kernel), 272 * r11, r12 (SRR0), and r9 (SRR1). 273 * 274 * Note2: once we have set r1 we are in a position to take exceptions 275 * again, and we could thus set MSR:RI at that point. 276 */ 277 278 /* 279 * Exception vectors. 280 */ 281 #ifdef CONFIG_PPC_BOOK3S 282 #define START_EXCEPTION(n, label) \ 283 . = n; \ 284 DO_KVM n; \ 285 label: 286 287 #else 288 #define START_EXCEPTION(n, label) \ 289 . = n; \ 290 label: 291 292 #endif 293 294 #define EXCEPTION(n, label, hdlr, xfer) \ 295 START_EXCEPTION(n, label) \ 296 EXCEPTION_PROLOG; \ 297 addi r3,r1,STACK_FRAME_OVERHEAD; \ 298 xfer(n, hdlr) 299 300 #define EXC_XFER_TEMPLATE(hdlr, trap, msr, tfer, ret) \ 301 li r10,trap; \ 302 stw r10,_TRAP(r11); \ 303 LOAD_REG_IMMEDIATE(r10, msr); \ 304 bl tfer; \ 305 .long hdlr; \ 306 .long ret 307 308 #define EXC_XFER_STD(n, hdlr) \ 309 EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, transfer_to_handler_full, \ 310 ret_from_except_full) 311 312 #define EXC_XFER_LITE(n, hdlr) \ 313 EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, transfer_to_handler, \ 314 ret_from_except) 315 316 .macro vmap_stack_overflow_exception 317 #ifdef CONFIG_VMAP_STACK 318 #ifdef CONFIG_SMP 319 mfspr r1, SPRN_SPRG_THREAD 320 lwz r1, TASK_CPU - THREAD(r1) 321 slwi r1, r1, 3 322 addis r1, r1, emergency_ctx@ha 323 #else 324 lis r1, emergency_ctx@ha 325 #endif 326 lwz r1, emergency_ctx@l(r1) 327 cmpwi cr1, r1, 0 328 bne cr1, 1f 329 lis r1, init_thread_union@ha 330 addi r1, r1, init_thread_union@l 331 1: addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE 332 EXCEPTION_PROLOG_2 333 SAVE_NVGPRS(r11) 334 addi r3, r1, STACK_FRAME_OVERHEAD 335 EXC_XFER_STD(0, stack_overflow_exception) 336 #endif 337 .endm 338 339 #endif /* __HEAD_32_H__ */ 340