Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* tlb-miss.S: TLB miss handlers |
| 2 | * |
| 3 | * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. |
| 4 | * Written by David Howells (dhowells@redhat.com) |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/sys.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/linkage.h> |
| 14 | #include <asm/page.h> |
| 15 | #include <asm/pgtable.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <asm/spr-regs.h> |
| 17 | |
Denys Vlasenko | b6f4e45 | 2010-02-20 01:03:56 +0100 | [diff] [blame] | 18 | .section .text..tlbmiss |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | .balign 4 |
| 20 | |
| 21 | .globl __entry_insn_mmu_miss |
| 22 | __entry_insn_mmu_miss: |
| 23 | break |
| 24 | nop |
| 25 | |
| 26 | .globl __entry_insn_mmu_exception |
| 27 | __entry_insn_mmu_exception: |
| 28 | break |
| 29 | nop |
| 30 | |
| 31 | .globl __entry_data_mmu_miss |
| 32 | __entry_data_mmu_miss: |
| 33 | break |
| 34 | nop |
| 35 | |
| 36 | .globl __entry_data_mmu_exception |
| 37 | __entry_data_mmu_exception: |
| 38 | break |
| 39 | nop |
| 40 | |
| 41 | ############################################################################### |
| 42 | # |
| 43 | # handle a lookup failure of one sort or another in a kernel TLB handler |
| 44 | # On entry: |
| 45 | # GR29 - faulting address |
| 46 | # SCR2 - saved CCR |
| 47 | # |
| 48 | ############################################################################### |
| 49 | .type __tlb_kernel_fault,@function |
| 50 | __tlb_kernel_fault: |
| 51 | # see if we're supposed to re-enable single-step mode upon return |
| 52 | sethi.p %hi(__break_tlb_miss_return_break),gr30 |
| 53 | setlo %lo(__break_tlb_miss_return_break),gr30 |
| 54 | movsg pcsr,gr31 |
| 55 | |
| 56 | subcc gr31,gr30,gr0,icc0 |
| 57 | beq icc0,#0,__tlb_kernel_fault_sstep |
| 58 | |
| 59 | movsg scr2,gr30 |
| 60 | movgs gr30,ccr |
| 61 | movgs gr29,scr2 /* save EAR0 value */ |
| 62 | sethi.p %hi(__kernel_current_task),gr29 |
| 63 | setlo %lo(__kernel_current_task),gr29 |
| 64 | ldi.p @(gr29,#0),gr29 /* restore GR29 */ |
| 65 | |
| 66 | bra __entry_kernel_handle_mmu_fault |
| 67 | |
| 68 | # we've got to re-enable single-stepping |
| 69 | __tlb_kernel_fault_sstep: |
| 70 | sethi.p %hi(__break_tlb_miss_real_return_info),gr30 |
| 71 | setlo %lo(__break_tlb_miss_real_return_info),gr30 |
| 72 | lddi @(gr30,0),gr30 |
| 73 | movgs gr30,pcsr |
| 74 | movgs gr31,psr |
| 75 | |
| 76 | movsg scr2,gr30 |
| 77 | movgs gr30,ccr |
| 78 | movgs gr29,scr2 /* save EAR0 value */ |
| 79 | sethi.p %hi(__kernel_current_task),gr29 |
| 80 | setlo %lo(__kernel_current_task),gr29 |
| 81 | ldi.p @(gr29,#0),gr29 /* restore GR29 */ |
| 82 | bra __entry_kernel_handle_mmu_fault_sstep |
| 83 | |
| 84 | .size __tlb_kernel_fault, .-__tlb_kernel_fault |
| 85 | |
| 86 | ############################################################################### |
| 87 | # |
| 88 | # handle a lookup failure of one sort or another in a user TLB handler |
| 89 | # On entry: |
| 90 | # GR28 - faulting address |
| 91 | # SCR2 - saved CCR |
| 92 | # |
| 93 | ############################################################################### |
| 94 | .type __tlb_user_fault,@function |
| 95 | __tlb_user_fault: |
| 96 | # see if we're supposed to re-enable single-step mode upon return |
| 97 | sethi.p %hi(__break_tlb_miss_return_break),gr30 |
| 98 | setlo %lo(__break_tlb_miss_return_break),gr30 |
| 99 | movsg pcsr,gr31 |
| 100 | subcc gr31,gr30,gr0,icc0 |
| 101 | beq icc0,#0,__tlb_user_fault_sstep |
| 102 | |
| 103 | movsg scr2,gr30 |
| 104 | movgs gr30,ccr |
| 105 | bra __entry_uspace_handle_mmu_fault |
| 106 | |
| 107 | # we've got to re-enable single-stepping |
| 108 | __tlb_user_fault_sstep: |
| 109 | sethi.p %hi(__break_tlb_miss_real_return_info),gr30 |
| 110 | setlo %lo(__break_tlb_miss_real_return_info),gr30 |
| 111 | lddi @(gr30,0),gr30 |
| 112 | movgs gr30,pcsr |
| 113 | movgs gr31,psr |
| 114 | movsg scr2,gr30 |
| 115 | movgs gr30,ccr |
| 116 | bra __entry_uspace_handle_mmu_fault_sstep |
| 117 | |
| 118 | .size __tlb_user_fault, .-__tlb_user_fault |
| 119 | |
| 120 | ############################################################################### |
| 121 | # |
| 122 | # Kernel instruction TLB miss handler |
| 123 | # On entry: |
| 124 | # GR1 - kernel stack pointer |
| 125 | # GR28 - saved exception frame pointer |
| 126 | # GR29 - faulting address |
| 127 | # GR31 - EAR0 ^ SCR0 |
| 128 | # SCR0 - base of virtual range covered by cached PGE from last ITLB miss (or 0xffffffff) |
| 129 | # DAMR3 - mapped page directory |
| 130 | # DAMR4 - mapped page table as matched by SCR0 |
| 131 | # |
| 132 | ############################################################################### |
| 133 | .globl __entry_kernel_insn_tlb_miss |
| 134 | .type __entry_kernel_insn_tlb_miss,@function |
| 135 | __entry_kernel_insn_tlb_miss: |
| 136 | #if 0 |
| 137 | sethi.p %hi(0xe1200004),gr30 |
| 138 | setlo %lo(0xe1200004),gr30 |
| 139 | st gr0,@(gr30,gr0) |
| 140 | sethi.p %hi(0xffc00100),gr30 |
| 141 | setlo %lo(0xffc00100),gr30 |
| 142 | sth gr30,@(gr30,gr0) |
| 143 | membar |
| 144 | #endif |
| 145 | |
| 146 | movsg ccr,gr30 /* save CCR */ |
| 147 | movgs gr30,scr2 |
| 148 | |
| 149 | # see if the cached page table mapping is appropriate |
| 150 | srlicc.p gr31,#26,gr0,icc0 |
| 151 | setlos 0x3ffc,gr30 |
| 152 | srli.p gr29,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| 153 | bne icc0,#0,__itlb_k_PTD_miss |
| 154 | |
| 155 | __itlb_k_PTD_mapped: |
| 156 | # access the PTD with EAR0[25:14] |
| 157 | # - DAMLR4 points to the virtual address of the appropriate page table |
| 158 | # - the PTD holds 4096 PTEs |
| 159 | # - the PTD must be accessed uncached |
| 160 | # - the PTE must be marked accessed if it was valid |
| 161 | # |
| 162 | and gr31,gr30,gr31 |
| 163 | movsg damlr4,gr30 |
| 164 | add gr30,gr31,gr31 |
| 165 | ldi @(gr31,#0),gr30 /* fetch the PTE */ |
| 166 | andicc gr30,#_PAGE_PRESENT,gr0,icc0 |
| 167 | ori.p gr30,#_PAGE_ACCESSED,gr30 |
| 168 | beq icc0,#0,__tlb_kernel_fault /* jump if PTE invalid */ |
| 169 | sti.p gr30,@(gr31,#0) /* update the PTE */ |
| 170 | andi gr30,#~_PAGE_ACCESSED,gr30 |
| 171 | |
| 172 | # we're using IAMR1 as an extra TLB entry |
| 173 | # - punt the entry here (if valid) to the real TLB and then replace with the new PTE |
| 174 | # - need to check DAMR1 lest we cause an multiple-DAT-hit exception |
| 175 | # - IAMPR1 has no WP bit, and we mustn't lose WP information |
| 176 | movsg iampr1,gr31 |
| 177 | andicc gr31,#xAMPRx_V,gr0,icc0 |
| 178 | setlos.p 0xfffff000,gr31 |
| 179 | beq icc0,#0,__itlb_k_nopunt /* punt not required */ |
| 180 | |
| 181 | movsg iamlr1,gr31 |
| 182 | movgs gr31,tplr /* set TPLR.CXN */ |
| 183 | tlbpr gr31,gr0,#4,#0 /* delete matches from TLB, IAMR1, DAMR1 */ |
| 184 | |
| 185 | movsg dampr1,gr31 |
| 186 | ori gr31,#xAMPRx_V,gr31 /* entry was invalidated by tlbpr #4 */ |
| 187 | movgs gr31,tppr |
| 188 | movsg iamlr1,gr31 /* set TPLR.CXN */ |
| 189 | movgs gr31,tplr |
| 190 | tlbpr gr31,gr0,#2,#0 /* save to the TLB */ |
| 191 | movsg tpxr,gr31 /* check the TLB write error flag */ |
| 192 | andicc.p gr31,#TPXR_E,gr0,icc0 |
| 193 | setlos #0xfffff000,gr31 |
| 194 | bne icc0,#0,__tlb_kernel_fault |
| 195 | |
| 196 | __itlb_k_nopunt: |
| 197 | |
| 198 | # assemble the new TLB entry |
| 199 | and gr29,gr31,gr29 |
| 200 | movsg cxnr,gr31 |
| 201 | or gr29,gr31,gr29 |
| 202 | movgs gr29,iamlr1 /* xAMLR = address | context number */ |
| 203 | movgs gr30,iampr1 |
| 204 | movgs gr29,damlr1 |
| 205 | movgs gr30,dampr1 |
| 206 | |
| 207 | # return, restoring registers |
| 208 | movsg scr2,gr30 |
| 209 | movgs gr30,ccr |
| 210 | sethi.p %hi(__kernel_current_task),gr29 |
| 211 | setlo %lo(__kernel_current_task),gr29 |
| 212 | ldi @(gr29,#0),gr29 |
| 213 | rett #0 |
| 214 | beq icc0,#3,0 /* prevent icache prefetch */ |
| 215 | |
| 216 | # the PTE we want wasn't in the PTD we have mapped, so we need to go looking for a more |
| 217 | # appropriate page table and map that instead |
| 218 | # - access the PGD with EAR0[31:26] |
| 219 | # - DAMLR3 points to the virtual address of the page directory |
| 220 | # - the PGD holds 64 PGEs and each PGE/PME points to a set of page tables |
| 221 | __itlb_k_PTD_miss: |
| 222 | srli gr29,#26,gr31 /* calculate PGE offset */ |
| 223 | slli gr31,#8,gr31 /* and clear bottom bits */ |
| 224 | |
| 225 | movsg damlr3,gr30 |
| 226 | ld @(gr31,gr30),gr30 /* access the PGE */ |
| 227 | |
| 228 | andicc.p gr30,#_PAGE_PRESENT,gr0,icc0 |
| 229 | andicc gr30,#xAMPRx_SS,gr0,icc1 |
| 230 | |
| 231 | # map this PTD instead and record coverage address |
| 232 | ori.p gr30,#xAMPRx_L|xAMPRx_SS_16Kb|xAMPRx_S|xAMPRx_C|xAMPRx_V,gr30 |
| 233 | beq icc0,#0,__tlb_kernel_fault /* jump if PGE not present */ |
| 234 | slli.p gr31,#18,gr31 |
| 235 | bne icc1,#0,__itlb_k_bigpage |
| 236 | movgs gr30,dampr4 |
| 237 | movgs gr31,scr0 |
| 238 | |
| 239 | # we can now resume normal service |
| 240 | setlos 0x3ffc,gr30 |
| 241 | srli.p gr29,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| 242 | bra __itlb_k_PTD_mapped |
| 243 | |
| 244 | __itlb_k_bigpage: |
| 245 | break |
| 246 | nop |
| 247 | |
| 248 | .size __entry_kernel_insn_tlb_miss, .-__entry_kernel_insn_tlb_miss |
| 249 | |
| 250 | ############################################################################### |
| 251 | # |
| 252 | # Kernel data TLB miss handler |
| 253 | # On entry: |
| 254 | # GR1 - kernel stack pointer |
| 255 | # GR28 - saved exception frame pointer |
| 256 | # GR29 - faulting address |
| 257 | # GR31 - EAR0 ^ SCR1 |
| 258 | # SCR1 - base of virtual range covered by cached PGE from last DTLB miss (or 0xffffffff) |
| 259 | # DAMR3 - mapped page directory |
| 260 | # DAMR5 - mapped page table as matched by SCR1 |
| 261 | # |
| 262 | ############################################################################### |
| 263 | .globl __entry_kernel_data_tlb_miss |
| 264 | .type __entry_kernel_data_tlb_miss,@function |
| 265 | __entry_kernel_data_tlb_miss: |
| 266 | #if 0 |
| 267 | sethi.p %hi(0xe1200004),gr30 |
| 268 | setlo %lo(0xe1200004),gr30 |
| 269 | st gr0,@(gr30,gr0) |
| 270 | sethi.p %hi(0xffc00100),gr30 |
| 271 | setlo %lo(0xffc00100),gr30 |
| 272 | sth gr30,@(gr30,gr0) |
| 273 | membar |
| 274 | #endif |
| 275 | |
| 276 | movsg ccr,gr30 /* save CCR */ |
| 277 | movgs gr30,scr2 |
| 278 | |
| 279 | # see if the cached page table mapping is appropriate |
| 280 | srlicc.p gr31,#26,gr0,icc0 |
| 281 | setlos 0x3ffc,gr30 |
| 282 | srli.p gr29,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| 283 | bne icc0,#0,__dtlb_k_PTD_miss |
| 284 | |
| 285 | __dtlb_k_PTD_mapped: |
| 286 | # access the PTD with EAR0[25:14] |
| 287 | # - DAMLR5 points to the virtual address of the appropriate page table |
| 288 | # - the PTD holds 4096 PTEs |
| 289 | # - the PTD must be accessed uncached |
| 290 | # - the PTE must be marked accessed if it was valid |
| 291 | # |
| 292 | and gr31,gr30,gr31 |
| 293 | movsg damlr5,gr30 |
| 294 | add gr30,gr31,gr31 |
| 295 | ldi @(gr31,#0),gr30 /* fetch the PTE */ |
| 296 | andicc gr30,#_PAGE_PRESENT,gr0,icc0 |
| 297 | ori.p gr30,#_PAGE_ACCESSED,gr30 |
| 298 | beq icc0,#0,__tlb_kernel_fault /* jump if PTE invalid */ |
| 299 | sti.p gr30,@(gr31,#0) /* update the PTE */ |
| 300 | andi gr30,#~_PAGE_ACCESSED,gr30 |
| 301 | |
| 302 | # we're using DAMR1 as an extra TLB entry |
| 303 | # - punt the entry here (if valid) to the real TLB and then replace with the new PTE |
| 304 | # - need to check IAMR1 lest we cause an multiple-DAT-hit exception |
| 305 | movsg dampr1,gr31 |
| 306 | andicc gr31,#xAMPRx_V,gr0,icc0 |
| 307 | setlos.p 0xfffff000,gr31 |
| 308 | beq icc0,#0,__dtlb_k_nopunt /* punt not required */ |
| 309 | |
| 310 | movsg damlr1,gr31 |
| 311 | movgs gr31,tplr /* set TPLR.CXN */ |
| 312 | tlbpr gr31,gr0,#4,#0 /* delete matches from TLB, IAMR1, DAMR1 */ |
| 313 | |
| 314 | movsg dampr1,gr31 |
| 315 | ori gr31,#xAMPRx_V,gr31 /* entry was invalidated by tlbpr #4 */ |
| 316 | movgs gr31,tppr |
| 317 | movsg damlr1,gr31 /* set TPLR.CXN */ |
| 318 | movgs gr31,tplr |
| 319 | tlbpr gr31,gr0,#2,#0 /* save to the TLB */ |
| 320 | movsg tpxr,gr31 /* check the TLB write error flag */ |
| 321 | andicc.p gr31,#TPXR_E,gr0,icc0 |
| 322 | setlos #0xfffff000,gr31 |
| 323 | bne icc0,#0,__tlb_kernel_fault |
| 324 | |
| 325 | __dtlb_k_nopunt: |
| 326 | |
| 327 | # assemble the new TLB entry |
| 328 | and gr29,gr31,gr29 |
| 329 | movsg cxnr,gr31 |
| 330 | or gr29,gr31,gr29 |
| 331 | movgs gr29,iamlr1 /* xAMLR = address | context number */ |
| 332 | movgs gr30,iampr1 |
| 333 | movgs gr29,damlr1 |
| 334 | movgs gr30,dampr1 |
| 335 | |
| 336 | # return, restoring registers |
| 337 | movsg scr2,gr30 |
| 338 | movgs gr30,ccr |
| 339 | sethi.p %hi(__kernel_current_task),gr29 |
| 340 | setlo %lo(__kernel_current_task),gr29 |
| 341 | ldi @(gr29,#0),gr29 |
| 342 | rett #0 |
| 343 | beq icc0,#3,0 /* prevent icache prefetch */ |
| 344 | |
| 345 | # the PTE we want wasn't in the PTD we have mapped, so we need to go looking for a more |
| 346 | # appropriate page table and map that instead |
| 347 | # - access the PGD with EAR0[31:26] |
| 348 | # - DAMLR3 points to the virtual address of the page directory |
| 349 | # - the PGD holds 64 PGEs and each PGE/PME points to a set of page tables |
| 350 | __dtlb_k_PTD_miss: |
| 351 | srli gr29,#26,gr31 /* calculate PGE offset */ |
| 352 | slli gr31,#8,gr31 /* and clear bottom bits */ |
| 353 | |
| 354 | movsg damlr3,gr30 |
| 355 | ld @(gr31,gr30),gr30 /* access the PGE */ |
| 356 | |
| 357 | andicc.p gr30,#_PAGE_PRESENT,gr0,icc0 |
| 358 | andicc gr30,#xAMPRx_SS,gr0,icc1 |
| 359 | |
| 360 | # map this PTD instead and record coverage address |
| 361 | ori.p gr30,#xAMPRx_L|xAMPRx_SS_16Kb|xAMPRx_S|xAMPRx_C|xAMPRx_V,gr30 |
| 362 | beq icc0,#0,__tlb_kernel_fault /* jump if PGE not present */ |
| 363 | slli.p gr31,#18,gr31 |
| 364 | bne icc1,#0,__dtlb_k_bigpage |
| 365 | movgs gr30,dampr5 |
| 366 | movgs gr31,scr1 |
| 367 | |
| 368 | # we can now resume normal service |
| 369 | setlos 0x3ffc,gr30 |
| 370 | srli.p gr29,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| 371 | bra __dtlb_k_PTD_mapped |
| 372 | |
| 373 | __dtlb_k_bigpage: |
| 374 | break |
| 375 | nop |
| 376 | |
| 377 | .size __entry_kernel_data_tlb_miss, .-__entry_kernel_data_tlb_miss |
| 378 | |
| 379 | ############################################################################### |
| 380 | # |
| 381 | # Userspace instruction TLB miss handler (with PGE prediction) |
| 382 | # On entry: |
| 383 | # GR28 - faulting address |
| 384 | # GR31 - EAR0 ^ SCR0 |
| 385 | # SCR0 - base of virtual range covered by cached PGE from last ITLB miss (or 0xffffffff) |
| 386 | # DAMR3 - mapped page directory |
| 387 | # DAMR4 - mapped page table as matched by SCR0 |
| 388 | # |
| 389 | ############################################################################### |
| 390 | .globl __entry_user_insn_tlb_miss |
| 391 | .type __entry_user_insn_tlb_miss,@function |
| 392 | __entry_user_insn_tlb_miss: |
| 393 | #if 0 |
| 394 | sethi.p %hi(0xe1200004),gr30 |
| 395 | setlo %lo(0xe1200004),gr30 |
| 396 | st gr0,@(gr30,gr0) |
| 397 | sethi.p %hi(0xffc00100),gr30 |
| 398 | setlo %lo(0xffc00100),gr30 |
| 399 | sth gr30,@(gr30,gr0) |
| 400 | membar |
| 401 | #endif |
| 402 | |
| 403 | movsg ccr,gr30 /* save CCR */ |
| 404 | movgs gr30,scr2 |
| 405 | |
| 406 | # see if the cached page table mapping is appropriate |
| 407 | srlicc.p gr31,#26,gr0,icc0 |
| 408 | setlos 0x3ffc,gr30 |
| 409 | srli.p gr28,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| 410 | bne icc0,#0,__itlb_u_PTD_miss |
| 411 | |
| 412 | __itlb_u_PTD_mapped: |
| 413 | # access the PTD with EAR0[25:14] |
| 414 | # - DAMLR4 points to the virtual address of the appropriate page table |
| 415 | # - the PTD holds 4096 PTEs |
| 416 | # - the PTD must be accessed uncached |
| 417 | # - the PTE must be marked accessed if it was valid |
| 418 | # |
| 419 | and gr31,gr30,gr31 |
| 420 | movsg damlr4,gr30 |
| 421 | add gr30,gr31,gr31 |
| 422 | ldi @(gr31,#0),gr30 /* fetch the PTE */ |
| 423 | andicc gr30,#_PAGE_PRESENT,gr0,icc0 |
| 424 | ori.p gr30,#_PAGE_ACCESSED,gr30 |
| 425 | beq icc0,#0,__tlb_user_fault /* jump if PTE invalid */ |
| 426 | sti.p gr30,@(gr31,#0) /* update the PTE */ |
| 427 | andi gr30,#~_PAGE_ACCESSED,gr30 |
| 428 | |
| 429 | # we're using IAMR1/DAMR1 as an extra TLB entry |
| 430 | # - punt the entry here (if valid) to the real TLB and then replace with the new PTE |
| 431 | movsg dampr1,gr31 |
| 432 | andicc gr31,#xAMPRx_V,gr0,icc0 |
| 433 | setlos.p 0xfffff000,gr31 |
| 434 | beq icc0,#0,__itlb_u_nopunt /* punt not required */ |
| 435 | |
| 436 | movsg dampr1,gr31 |
| 437 | movgs gr31,tppr |
| 438 | movsg damlr1,gr31 /* set TPLR.CXN */ |
| 439 | movgs gr31,tplr |
| 440 | tlbpr gr31,gr0,#2,#0 /* save to the TLB */ |
| 441 | movsg tpxr,gr31 /* check the TLB write error flag */ |
| 442 | andicc.p gr31,#TPXR_E,gr0,icc0 |
| 443 | setlos #0xfffff000,gr31 |
| 444 | bne icc0,#0,__tlb_user_fault |
| 445 | |
| 446 | __itlb_u_nopunt: |
| 447 | |
| 448 | # assemble the new TLB entry |
| 449 | and gr28,gr31,gr28 |
| 450 | movsg cxnr,gr31 |
| 451 | or gr28,gr31,gr28 |
| 452 | movgs gr28,iamlr1 /* xAMLR = address | context number */ |
| 453 | movgs gr30,iampr1 |
| 454 | movgs gr28,damlr1 |
| 455 | movgs gr30,dampr1 |
| 456 | |
| 457 | # return, restoring registers |
| 458 | movsg scr2,gr30 |
| 459 | movgs gr30,ccr |
| 460 | rett #0 |
| 461 | beq icc0,#3,0 /* prevent icache prefetch */ |
| 462 | |
| 463 | # the PTE we want wasn't in the PTD we have mapped, so we need to go looking for a more |
| 464 | # appropriate page table and map that instead |
| 465 | # - access the PGD with EAR0[31:26] |
| 466 | # - DAMLR3 points to the virtual address of the page directory |
| 467 | # - the PGD holds 64 PGEs and each PGE/PME points to a set of page tables |
| 468 | __itlb_u_PTD_miss: |
| 469 | srli gr28,#26,gr31 /* calculate PGE offset */ |
| 470 | slli gr31,#8,gr31 /* and clear bottom bits */ |
| 471 | |
| 472 | movsg damlr3,gr30 |
| 473 | ld @(gr31,gr30),gr30 /* access the PGE */ |
| 474 | |
| 475 | andicc.p gr30,#_PAGE_PRESENT,gr0,icc0 |
| 476 | andicc gr30,#xAMPRx_SS,gr0,icc1 |
| 477 | |
| 478 | # map this PTD instead and record coverage address |
| 479 | ori.p gr30,#xAMPRx_L|xAMPRx_SS_16Kb|xAMPRx_S|xAMPRx_C|xAMPRx_V,gr30 |
| 480 | beq icc0,#0,__tlb_user_fault /* jump if PGE not present */ |
| 481 | slli.p gr31,#18,gr31 |
| 482 | bne icc1,#0,__itlb_u_bigpage |
| 483 | movgs gr30,dampr4 |
| 484 | movgs gr31,scr0 |
| 485 | |
| 486 | # we can now resume normal service |
| 487 | setlos 0x3ffc,gr30 |
| 488 | srli.p gr28,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| 489 | bra __itlb_u_PTD_mapped |
| 490 | |
| 491 | __itlb_u_bigpage: |
| 492 | break |
| 493 | nop |
| 494 | |
| 495 | .size __entry_user_insn_tlb_miss, .-__entry_user_insn_tlb_miss |
| 496 | |
| 497 | ############################################################################### |
| 498 | # |
| 499 | # Userspace data TLB miss handler |
| 500 | # On entry: |
| 501 | # GR28 - faulting address |
| 502 | # GR31 - EAR0 ^ SCR1 |
| 503 | # SCR1 - base of virtual range covered by cached PGE from last DTLB miss (or 0xffffffff) |
| 504 | # DAMR3 - mapped page directory |
| 505 | # DAMR5 - mapped page table as matched by SCR1 |
| 506 | # |
| 507 | ############################################################################### |
| 508 | .globl __entry_user_data_tlb_miss |
| 509 | .type __entry_user_data_tlb_miss,@function |
| 510 | __entry_user_data_tlb_miss: |
| 511 | #if 0 |
| 512 | sethi.p %hi(0xe1200004),gr30 |
| 513 | setlo %lo(0xe1200004),gr30 |
| 514 | st gr0,@(gr30,gr0) |
| 515 | sethi.p %hi(0xffc00100),gr30 |
| 516 | setlo %lo(0xffc00100),gr30 |
| 517 | sth gr30,@(gr30,gr0) |
| 518 | membar |
| 519 | #endif |
| 520 | |
| 521 | movsg ccr,gr30 /* save CCR */ |
| 522 | movgs gr30,scr2 |
| 523 | |
| 524 | # see if the cached page table mapping is appropriate |
| 525 | srlicc.p gr31,#26,gr0,icc0 |
| 526 | setlos 0x3ffc,gr30 |
| 527 | srli.p gr28,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| 528 | bne icc0,#0,__dtlb_u_PTD_miss |
| 529 | |
| 530 | __dtlb_u_PTD_mapped: |
| 531 | # access the PTD with EAR0[25:14] |
| 532 | # - DAMLR5 points to the virtual address of the appropriate page table |
| 533 | # - the PTD holds 4096 PTEs |
| 534 | # - the PTD must be accessed uncached |
| 535 | # - the PTE must be marked accessed if it was valid |
| 536 | # |
| 537 | and gr31,gr30,gr31 |
| 538 | movsg damlr5,gr30 |
| 539 | |
| 540 | __dtlb_u_using_iPTD: |
| 541 | add gr30,gr31,gr31 |
| 542 | ldi @(gr31,#0),gr30 /* fetch the PTE */ |
| 543 | andicc gr30,#_PAGE_PRESENT,gr0,icc0 |
| 544 | ori.p gr30,#_PAGE_ACCESSED,gr30 |
| 545 | beq icc0,#0,__tlb_user_fault /* jump if PTE invalid */ |
| 546 | sti.p gr30,@(gr31,#0) /* update the PTE */ |
| 547 | andi gr30,#~_PAGE_ACCESSED,gr30 |
| 548 | |
| 549 | # we're using DAMR1 as an extra TLB entry |
| 550 | # - punt the entry here (if valid) to the real TLB and then replace with the new PTE |
| 551 | movsg dampr1,gr31 |
| 552 | andicc gr31,#xAMPRx_V,gr0,icc0 |
| 553 | setlos.p 0xfffff000,gr31 |
| 554 | beq icc0,#0,__dtlb_u_nopunt /* punt not required */ |
| 555 | |
| 556 | movsg dampr1,gr31 |
| 557 | movgs gr31,tppr |
| 558 | movsg damlr1,gr31 /* set TPLR.CXN */ |
| 559 | movgs gr31,tplr |
| 560 | tlbpr gr31,gr0,#2,#0 /* save to the TLB */ |
| 561 | movsg tpxr,gr31 /* check the TLB write error flag */ |
| 562 | andicc.p gr31,#TPXR_E,gr0,icc0 |
| 563 | setlos #0xfffff000,gr31 |
| 564 | bne icc0,#0,__tlb_user_fault |
| 565 | |
| 566 | __dtlb_u_nopunt: |
| 567 | |
| 568 | # assemble the new TLB entry |
| 569 | and gr28,gr31,gr28 |
| 570 | movsg cxnr,gr31 |
| 571 | or gr28,gr31,gr28 |
| 572 | movgs gr28,iamlr1 /* xAMLR = address | context number */ |
| 573 | movgs gr30,iampr1 |
| 574 | movgs gr28,damlr1 |
| 575 | movgs gr30,dampr1 |
| 576 | |
| 577 | # return, restoring registers |
| 578 | movsg scr2,gr30 |
| 579 | movgs gr30,ccr |
| 580 | rett #0 |
| 581 | beq icc0,#3,0 /* prevent icache prefetch */ |
| 582 | |
| 583 | # the PTE we want wasn't in the PTD we have mapped, so we need to go looking for a more |
| 584 | # appropriate page table and map that instead |
| 585 | # - first of all, check the insn PGE cache - we may well get a hit there |
| 586 | # - access the PGD with EAR0[31:26] |
| 587 | # - DAMLR3 points to the virtual address of the page directory |
| 588 | # - the PGD holds 64 PGEs and each PGE/PME points to a set of page tables |
| 589 | __dtlb_u_PTD_miss: |
| 590 | movsg scr0,gr31 /* consult the insn-PGE-cache key */ |
| 591 | xor gr28,gr31,gr31 |
| 592 | srlicc gr31,#26,gr0,icc0 |
| 593 | srli gr28,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| 594 | bne icc0,#0,__dtlb_u_iPGE_miss |
| 595 | |
| 596 | # what we're looking for is covered by the insn-PGE-cache |
| 597 | setlos 0x3ffc,gr30 |
| 598 | and gr31,gr30,gr31 |
| 599 | movsg damlr4,gr30 |
| 600 | bra __dtlb_u_using_iPTD |
| 601 | |
| 602 | __dtlb_u_iPGE_miss: |
| 603 | srli gr28,#26,gr31 /* calculate PGE offset */ |
| 604 | slli gr31,#8,gr31 /* and clear bottom bits */ |
| 605 | |
| 606 | movsg damlr3,gr30 |
| 607 | ld @(gr31,gr30),gr30 /* access the PGE */ |
| 608 | |
| 609 | andicc.p gr30,#_PAGE_PRESENT,gr0,icc0 |
| 610 | andicc gr30,#xAMPRx_SS,gr0,icc1 |
| 611 | |
| 612 | # map this PTD instead and record coverage address |
| 613 | ori.p gr30,#xAMPRx_L|xAMPRx_SS_16Kb|xAMPRx_S|xAMPRx_C|xAMPRx_V,gr30 |
| 614 | beq icc0,#0,__tlb_user_fault /* jump if PGE not present */ |
| 615 | slli.p gr31,#18,gr31 |
| 616 | bne icc1,#0,__dtlb_u_bigpage |
| 617 | movgs gr30,dampr5 |
| 618 | movgs gr31,scr1 |
| 619 | |
| 620 | # we can now resume normal service |
| 621 | setlos 0x3ffc,gr30 |
| 622 | srli.p gr28,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| 623 | bra __dtlb_u_PTD_mapped |
| 624 | |
| 625 | __dtlb_u_bigpage: |
| 626 | break |
| 627 | nop |
| 628 | |
| 629 | .size __entry_user_data_tlb_miss, .-__entry_user_data_tlb_miss |