1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * rtrap.S: Preparing for return from trap on Sparc V9. 4 * 5 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz) 6 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu) 7 */ 8 9 10#include <asm/asi.h> 11#include <asm/pstate.h> 12#include <asm/ptrace.h> 13#include <asm/spitfire.h> 14#include <asm/head.h> 15#include <asm/visasm.h> 16#include <asm/processor.h> 17 18#ifdef CONFIG_CONTEXT_TRACKING 19# define SCHEDULE_USER schedule_user 20#else 21# define SCHEDULE_USER schedule 22#endif 23 24 .text 25 .align 32 26__handle_preemption: 27 call SCHEDULE_USER 28661: wrpr %g0, RTRAP_PSTATE, %pstate 29 /* If userspace is using ADI, it could potentially pass 30 * a pointer with version tag embedded in it. To maintain 31 * the ADI security, we must re-enable PSTATE.mcde before 32 * we continue execution in the kernel for another thread. 33 */ 34 .section .sun_m7_1insn_patch, "ax" 35 .word 661b 36 wrpr %g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate 37 .previous 38 ba,pt %xcc, __handle_preemption_continue 39 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate 40 41__handle_user_windows: 42 add %sp, PTREGS_OFF, %o0 43 call fault_in_user_windows 44661: wrpr %g0, RTRAP_PSTATE, %pstate 45 /* If userspace is using ADI, it could potentially pass 46 * a pointer with version tag embedded in it. To maintain 47 * the ADI security, we must re-enable PSTATE.mcde before 48 * we continue execution in the kernel for another thread. 49 */ 50 .section .sun_m7_1insn_patch, "ax" 51 .word 661b 52 wrpr %g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate 53 .previous 54 ba,pt %xcc, __handle_preemption_continue 55 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate 56 57__handle_userfpu: 58 rd %fprs, %l5 59 andcc %l5, FPRS_FEF, %g0 60 sethi %hi(TSTATE_PEF), %o0 61 be,a,pn %icc, __handle_userfpu_continue 62 andn %l1, %o0, %l1 63 ba,a,pt %xcc, __handle_userfpu_continue 64 65__handle_signal: 66 mov %l5, %o1 67 add %sp, PTREGS_OFF, %o0 68 mov %l0, %o2 69 call do_notify_resume 70661: wrpr %g0, RTRAP_PSTATE, %pstate 71 /* If userspace is using ADI, it could potentially pass 72 * a pointer with version tag embedded in it. To maintain 73 * the ADI security, we must re-enable PSTATE.mcde before 74 * we continue execution in the kernel for another thread. 75 */ 76 .section .sun_m7_1insn_patch, "ax" 77 .word 661b 78 wrpr %g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate 79 .previous 80 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate 81 82 /* Signal delivery can modify pt_regs tstate, so we must 83 * reload it. 84 */ 85 ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1 86 sethi %hi(0xf << 20), %l4 87 and %l1, %l4, %l4 88 andn %l1, %l4, %l1 89 ba,pt %xcc, __handle_preemption_continue 90 srl %l4, 20, %l4 91 92 /* When returning from a NMI (%pil==15) interrupt we want to 93 * avoid running softirqs, doing IRQ tracing, preempting, etc. 94 */ 95 .globl rtrap_nmi 96rtrap_nmi: ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1 97 sethi %hi(0xf << 20), %l4 98 and %l1, %l4, %l4 99 andn %l1, %l4, %l1 100 srl %l4, 20, %l4 101 ba,pt %xcc, rtrap_no_irq_enable 102 nop 103 /* Do not actually set the %pil here. We will do that 104 * below after we clear PSTATE_IE in the %pstate register. 105 * If we re-enable interrupts here, we can recurse down 106 * the hardirq stack potentially endlessly, causing a 107 * stack overflow. 108 */ 109 110 .align 64 111 .globl rtrap_irq, rtrap, irqsz_patchme, rtrap_xcall 112rtrap_irq: 113rtrap: 114 /* mm/ultra.S:xcall_report_regs KNOWS about this load. */ 115 ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1 116rtrap_xcall: 117 sethi %hi(0xf << 20), %l4 118 and %l1, %l4, %l4 119 andn %l1, %l4, %l1 120 srl %l4, 20, %l4 121#ifdef CONFIG_TRACE_IRQFLAGS 122 brnz,pn %l4, rtrap_no_irq_enable 123 nop 124 call trace_hardirqs_on 125 nop 126 /* Do not actually set the %pil here. We will do that 127 * below after we clear PSTATE_IE in the %pstate register. 128 * If we re-enable interrupts here, we can recurse down 129 * the hardirq stack potentially endlessly, causing a 130 * stack overflow. 131 * 132 * It is tempting to put this test and trace_hardirqs_on 133 * call at the 'rt_continue' label, but that will not work 134 * as that path hits unconditionally and we do not want to 135 * execute this in NMI return paths, for example. 136 */ 137#endif 138rtrap_no_irq_enable: 139 andcc %l1, TSTATE_PRIV, %l3 140 bne,pn %icc, to_kernel 141 nop 142 143 /* We must hold IRQs off and atomically test schedule+signal 144 * state, then hold them off all the way back to userspace. 145 * If we are returning to kernel, none of this matters. Note 146 * that we are disabling interrupts via PSTATE_IE, not using 147 * %pil. 148 * 149 * If we do not do this, there is a window where we would do 150 * the tests, later the signal/resched event arrives but we do 151 * not process it since we are still in kernel mode. It would 152 * take until the next local IRQ before the signal/resched 153 * event would be handled. 154 * 155 * This also means that if we have to deal with user 156 * windows, we have to redo all of these sched+signal checks 157 * with IRQs disabled. 158 */ 159to_user: wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate 160 wrpr 0, %pil 161__handle_preemption_continue: 162 ldx [%g6 + TI_FLAGS], %l0 163 sethi %hi(_TIF_USER_WORK_MASK), %o0 164 or %o0, %lo(_TIF_USER_WORK_MASK), %o0 165 andcc %l0, %o0, %g0 166 sethi %hi(TSTATE_PEF), %o0 167 be,pt %xcc, user_nowork 168 andcc %l1, %o0, %g0 169 andcc %l0, _TIF_NEED_RESCHED, %g0 170 bne,pn %xcc, __handle_preemption 171 andcc %l0, _TIF_DO_NOTIFY_RESUME_MASK, %g0 172 bne,pn %xcc, __handle_signal 173 ldub [%g6 + TI_WSAVED], %o2 174 brnz,pn %o2, __handle_user_windows 175 nop 176 sethi %hi(TSTATE_PEF), %o0 177 andcc %l1, %o0, %g0 178 179 /* This fpdepth clear is necessary for non-syscall rtraps only */ 180user_nowork: 181 bne,pn %xcc, __handle_userfpu 182 stb %g0, [%g6 + TI_FPDEPTH] 183__handle_userfpu_continue: 184 185rt_continue: ldx [%sp + PTREGS_OFF + PT_V9_G1], %g1 186 ldx [%sp + PTREGS_OFF + PT_V9_G2], %g2 187 188 ldx [%sp + PTREGS_OFF + PT_V9_G3], %g3 189 ldx [%sp + PTREGS_OFF + PT_V9_G4], %g4 190 ldx [%sp + PTREGS_OFF + PT_V9_G5], %g5 191 brz,pt %l3, 1f 192 mov %g6, %l2 193 194 /* Must do this before thread reg is clobbered below. */ 195 LOAD_PER_CPU_BASE(%g5, %g6, %i0, %i1, %i2) 1961: 197 ldx [%sp + PTREGS_OFF + PT_V9_G6], %g6 198 ldx [%sp + PTREGS_OFF + PT_V9_G7], %g7 199 200 /* Normal globals are restored, go to trap globals. */ 201661: wrpr %g0, RTRAP_PSTATE_AG_IRQOFF, %pstate 202 nop 203 .section .sun4v_2insn_patch, "ax" 204 .word 661b 205 wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate 206 SET_GL(1) 207 .previous 208 209 mov %l2, %g6 210 211 ldx [%sp + PTREGS_OFF + PT_V9_I0], %i0 212 ldx [%sp + PTREGS_OFF + PT_V9_I1], %i1 213 214 ldx [%sp + PTREGS_OFF + PT_V9_I2], %i2 215 ldx [%sp + PTREGS_OFF + PT_V9_I3], %i3 216 ldx [%sp + PTREGS_OFF + PT_V9_I4], %i4 217 ldx [%sp + PTREGS_OFF + PT_V9_I5], %i5 218 ldx [%sp + PTREGS_OFF + PT_V9_I6], %i6 219 ldx [%sp + PTREGS_OFF + PT_V9_I7], %i7 220 ldx [%sp + PTREGS_OFF + PT_V9_TPC], %l2 221 ldx [%sp + PTREGS_OFF + PT_V9_TNPC], %o2 222 223 ld [%sp + PTREGS_OFF + PT_V9_Y], %o3 224 wr %o3, %g0, %y 225 wrpr %l4, 0x0, %pil 226 wrpr %g0, 0x1, %tl 227 andn %l1, TSTATE_SYSCALL, %l1 228 wrpr %l1, %g0, %tstate 229 wrpr %l2, %g0, %tpc 230 wrpr %o2, %g0, %tnpc 231 232 brnz,pn %l3, kern_rtt 233 mov PRIMARY_CONTEXT, %l7 234 235661: ldxa [%l7 + %l7] ASI_DMMU, %l0 236 .section .sun4v_1insn_patch, "ax" 237 .word 661b 238 ldxa [%l7 + %l7] ASI_MMU, %l0 239 .previous 240 241 sethi %hi(sparc64_kern_pri_nuc_bits), %l1 242 ldx [%l1 + %lo(sparc64_kern_pri_nuc_bits)], %l1 243 or %l0, %l1, %l0 244 245661: stxa %l0, [%l7] ASI_DMMU 246 .section .sun4v_1insn_patch, "ax" 247 .word 661b 248 stxa %l0, [%l7] ASI_MMU 249 .previous 250 251 sethi %hi(KERNBASE), %l7 252 flush %l7 253 rdpr %wstate, %l1 254 rdpr %otherwin, %l2 255 srl %l1, 3, %l1 256 257661: wrpr %l2, %g0, %canrestore 258 .section .fast_win_ctrl_1insn_patch, "ax" 259 .word 661b 260 .word 0x89880000 ! normalw 261 .previous 262 263 wrpr %l1, %g0, %wstate 264 brnz,pt %l2, user_rtt_restore 265661: wrpr %g0, %g0, %otherwin 266 .section .fast_win_ctrl_1insn_patch, "ax" 267 .word 661b 268 nop 269 .previous 270 271 ldx [%g6 + TI_FLAGS], %g3 272 wr %g0, ASI_AIUP, %asi 273 rdpr %cwp, %g1 274 andcc %g3, _TIF_32BIT, %g0 275 sub %g1, 1, %g1 276 bne,pt %xcc, user_rtt_fill_32bit 277 wrpr %g1, %cwp 278 ba,a,pt %xcc, user_rtt_fill_64bit 279 nop 280 281user_rtt_fill_fixup_dax: 282 ba,pt %xcc, user_rtt_fill_fixup_common 283 mov 1, %g3 284 285user_rtt_fill_fixup_mna: 286 ba,pt %xcc, user_rtt_fill_fixup_common 287 mov 2, %g3 288 289user_rtt_fill_fixup: 290 ba,pt %xcc, user_rtt_fill_fixup_common 291 clr %g3 292 293user_rtt_pre_restore: 294 add %g1, 1, %g1 295 wrpr %g1, 0x0, %cwp 296 297user_rtt_restore: 298 restore 299 rdpr %canrestore, %g1 300 wrpr %g1, 0x0, %cleanwin 301 retry 302 nop 303 304kern_rtt: rdpr %canrestore, %g1 305 brz,pn %g1, kern_rtt_fill 306 nop 307kern_rtt_restore: 308 stw %g0, [%sp + PTREGS_OFF + PT_V9_MAGIC] 309 restore 310 retry 311 312to_kernel: 313#ifdef CONFIG_PREEMPTION 314 ldsw [%g6 + TI_PRE_COUNT], %l5 315 brnz %l5, kern_fpucheck 316 ldx [%g6 + TI_FLAGS], %l5 317 andcc %l5, _TIF_NEED_RESCHED, %g0 318 be,pt %xcc, kern_fpucheck 319 nop 320 cmp %l4, 0 321 bne,pn %xcc, kern_fpucheck 322 nop 323 call preempt_schedule_irq 324 nop 325 ba,pt %xcc, rtrap 326#endif 327kern_fpucheck: ldub [%g6 + TI_FPDEPTH], %l5 328 brz,pt %l5, rt_continue 329 srl %l5, 1, %o0 330 add %g6, TI_FPSAVED, %l6 331 ldub [%l6 + %o0], %l2 332 sub %l5, 2, %l5 333 334 add %g6, TI_GSR, %o1 335 andcc %l2, (FPRS_FEF|FPRS_DU), %g0 336 be,pt %icc, 2f 337 and %l2, FPRS_DL, %l6 338 andcc %l2, FPRS_FEF, %g0 339 be,pn %icc, 5f 340 sll %o0, 3, %o5 341 rd %fprs, %g1 342 343 wr %g1, FPRS_FEF, %fprs 344 ldx [%o1 + %o5], %g1 345 add %g6, TI_XFSR, %o1 346 sll %o0, 8, %o2 347 add %g6, TI_FPREGS, %o3 348 brz,pn %l6, 1f 349 add %g6, TI_FPREGS+0x40, %o4 350 351 membar #Sync 352 ldda [%o3 + %o2] ASI_BLK_P, %f0 353 ldda [%o4 + %o2] ASI_BLK_P, %f16 354 membar #Sync 3551: andcc %l2, FPRS_DU, %g0 356 be,pn %icc, 1f 357 wr %g1, 0, %gsr 358 add %o2, 0x80, %o2 359 membar #Sync 360 ldda [%o3 + %o2] ASI_BLK_P, %f32 361 ldda [%o4 + %o2] ASI_BLK_P, %f48 3621: membar #Sync 363 ldx [%o1 + %o5], %fsr 3642: stb %l5, [%g6 + TI_FPDEPTH] 365 ba,pt %xcc, rt_continue 366 nop 3675: wr %g0, FPRS_FEF, %fprs 368 sll %o0, 8, %o2 369 370 add %g6, TI_FPREGS+0x80, %o3 371 add %g6, TI_FPREGS+0xc0, %o4 372 membar #Sync 373 ldda [%o3 + %o2] ASI_BLK_P, %f32 374 ldda [%o4 + %o2] ASI_BLK_P, %f48 375 membar #Sync 376 wr %g0, FPRS_DU, %fprs 377 ba,pt %xcc, rt_continue 378 stb %l5, [%g6 + TI_FPDEPTH] 379