Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 1 | /* |
| 2 | * linux/arch/arm/kernel/head.S |
| 3 | * |
| 4 | * Copyright (C) 1994-2002 Russell King |
| 5 | * Copyright (c) 2003 ARM Limited |
| 6 | * All Rights Reserved |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | * |
| 12 | * Kernel startup code for all 32-bit CPUs |
| 13 | */ |
| 14 | #include <linux/linkage.h> |
| 15 | #include <linux/init.h> |
| 16 | |
| 17 | #include <asm/assembler.h> |
| 18 | #include <asm/cp15.h> |
| 19 | #include <asm/domain.h> |
| 20 | #include <asm/ptrace.h> |
| 21 | #include <asm/asm-offsets.h> |
| 22 | #include <asm/memory.h> |
| 23 | #include <asm/thread_info.h> |
| 24 | #include <asm/pgtable.h> |
| 25 | |
| 26 | #if defined(CONFIG_DEBUG_LL) && !defined(CONFIG_DEBUG_SEMIHOSTING) |
| 27 | #include CONFIG_DEBUG_LL_INCLUDE |
| 28 | #endif |
| 29 | |
| 30 | /* |
| 31 | * swapper_pg_dir is the virtual address of the initial page table. |
| 32 | * We place the page tables 16K below KERNEL_RAM_VADDR. Therefore, we must |
| 33 | * make sure that KERNEL_RAM_VADDR is correctly set. Currently, we expect |
| 34 | * the least significant 16 bits to be 0x8000, but we could probably |
| 35 | * relax this restriction to KERNEL_RAM_VADDR >= PAGE_OFFSET + 0x4000. |
| 36 | */ |
| 37 | #define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET) |
| 38 | #if (KERNEL_RAM_VADDR & 0xffff) != 0x8000 |
| 39 | #error KERNEL_RAM_VADDR must start at 0xXXXX8000 |
| 40 | #endif |
| 41 | |
| 42 | #ifdef CONFIG_ARM_LPAE |
| 43 | /* LPAE requires an additional page for the PGD */ |
| 44 | #define PG_DIR_SIZE 0x5000 |
| 45 | #define PMD_ORDER 3 |
| 46 | #else |
| 47 | #define PG_DIR_SIZE 0x4000 |
| 48 | #define PMD_ORDER 2 |
| 49 | #endif |
| 50 | |
| 51 | .globl swapper_pg_dir |
| 52 | .equ swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE |
| 53 | |
| 54 | .macro pgtbl, rd, phys |
| 55 | add \rd, \phys, #TEXT_OFFSET |
| 56 | sub \rd, \rd, #PG_DIR_SIZE |
| 57 | .endm |
| 58 | |
| 59 | /* |
| 60 | * Kernel startup entry point. |
| 61 | * --------------------------- |
| 62 | * |
| 63 | * This is normally called from the decompressor code. The requirements |
| 64 | * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0, |
| 65 | * r1 = machine nr, r2 = atags or dtb pointer. |
| 66 | * |
| 67 | * This code is mostly position independent, so if you link the kernel at |
| 68 | * 0xc0008000, you call this at __pa(0xc0008000). |
| 69 | * |
| 70 | * See linux/arch/arm/tools/mach-types for the complete list of machine |
| 71 | * numbers for r1. |
| 72 | * |
| 73 | * We're trying to keep crap to a minimum; DO NOT add any machine specific |
| 74 | * crap here - that's what the boot loader (or in extreme, well justified |
| 75 | * circumstances, zImage) is for. |
| 76 | */ |
| 77 | .arm |
| 78 | |
| 79 | __HEAD |
| 80 | ENTRY(stext) |
| 81 | ARM_BE8(setend be ) @ ensure we are in BE8 mode |
| 82 | |
| 83 | THUMB( badr r9, 1f ) @ Kernel is always entered in ARM. |
| 84 | THUMB( bx r9 ) @ If this is a Thumb-2 kernel, |
| 85 | THUMB( .thumb ) @ switch to Thumb now. |
| 86 | THUMB(1: ) |
| 87 | |
| 88 | #ifdef CONFIG_ARM_VIRT_EXT |
| 89 | bl __hyp_stub_install |
| 90 | #endif |
| 91 | @ ensure svc mode and all interrupts masked |
| 92 | safe_svcmode_maskall r9 |
| 93 | |
| 94 | mrc p15, 0, r9, c0, c0 @ get processor id |
| 95 | bl __lookup_processor_type @ r5=procinfo r9=cpuid |
| 96 | movs r10, r5 @ invalid processor (r5=0)? |
| 97 | THUMB( it eq ) @ force fixup-able long branch encoding |
| 98 | beq __error_p @ yes, error 'p' |
| 99 | |
| 100 | #ifdef CONFIG_ARM_LPAE |
| 101 | mrc p15, 0, r3, c0, c1, 4 @ read ID_MMFR0 |
| 102 | and r3, r3, #0xf @ extract VMSA support |
| 103 | cmp r3, #5 @ long-descriptor translation table format? |
| 104 | THUMB( it lo ) @ force fixup-able long branch encoding |
| 105 | blo __error_lpae @ only classic page table format |
| 106 | #endif |
| 107 | |
| 108 | #ifndef CONFIG_XIP_KERNEL |
| 109 | adr r3, 2f |
| 110 | ldmia r3, {r4, r8} |
| 111 | sub r4, r3, r4 @ (PHYS_OFFSET - PAGE_OFFSET) |
| 112 | add r8, r8, r4 @ PHYS_OFFSET |
| 113 | #else |
| 114 | ldr r8, =PLAT_PHYS_OFFSET @ always constant in this case |
| 115 | #endif |
| 116 | |
| 117 | /* |
| 118 | * r1 = machine no, r2 = atags or dtb, |
| 119 | * r8 = phys_offset, r9 = cpuid, r10 = procinfo |
| 120 | */ |
| 121 | bl __vet_atags |
| 122 | #ifdef CONFIG_SMP_ON_UP |
| 123 | bl __fixup_smp |
| 124 | #endif |
| 125 | #ifdef CONFIG_ARM_PATCH_PHYS_VIRT |
| 126 | bl __fixup_pv_table |
| 127 | #endif |
| 128 | bl __create_page_tables |
| 129 | |
| 130 | /* |
| 131 | * The following calls CPU specific code in a position independent |
| 132 | * manner. See arch/arm/mm/proc-*.S for details. r10 = base of |
| 133 | * xxx_proc_info structure selected by __lookup_processor_type |
| 134 | * above. |
| 135 | * |
| 136 | * The processor init function will be called with: |
| 137 | * r1 - machine type |
| 138 | * r2 - boot data (atags/dt) pointer |
| 139 | * r4 - translation table base (low word) |
| 140 | * r5 - translation table base (high word, if LPAE) |
| 141 | * r8 - translation table base 1 (pfn if LPAE) |
| 142 | * r9 - cpuid |
| 143 | * r13 - virtual address for __enable_mmu -> __turn_mmu_on |
| 144 | * |
| 145 | * On return, the CPU will be ready for the MMU to be turned on, |
| 146 | * r0 will hold the CPU control register value, r1, r2, r4, and |
| 147 | * r9 will be preserved. r5 will also be preserved if LPAE. |
| 148 | */ |
| 149 | ldr r13, =__mmap_switched @ address to jump to after |
| 150 | @ mmu has been enabled |
| 151 | badr lr, 1f @ return (PIC) address |
| 152 | #ifdef CONFIG_ARM_LPAE |
| 153 | mov r5, #0 @ high TTBR0 |
| 154 | mov r8, r4, lsr #12 @ TTBR1 is swapper_pg_dir pfn |
| 155 | #else |
| 156 | mov r8, r4 @ set TTBR1 to swapper_pg_dir |
| 157 | #endif |
| 158 | ldr r12, [r10, #PROCINFO_INITFUNC] |
| 159 | add r12, r12, r10 |
| 160 | ret r12 |
| 161 | 1: b __enable_mmu |
| 162 | ENDPROC(stext) |
| 163 | .ltorg |
| 164 | #ifndef CONFIG_XIP_KERNEL |
| 165 | 2: .long . |
| 166 | .long PAGE_OFFSET |
| 167 | #endif |
| 168 | |
| 169 | /* |
| 170 | * Setup the initial page tables. We only setup the barest |
| 171 | * amount which are required to get the kernel running, which |
| 172 | * generally means mapping in the kernel code. |
| 173 | * |
| 174 | * r8 = phys_offset, r9 = cpuid, r10 = procinfo |
| 175 | * |
| 176 | * Returns: |
| 177 | * r0, r3, r5-r7 corrupted |
| 178 | * r4 = physical page table address |
| 179 | */ |
| 180 | __create_page_tables: |
| 181 | pgtbl r4, r8 @ page table address |
| 182 | |
| 183 | /* |
| 184 | * Clear the swapper page table |
| 185 | */ |
| 186 | mov r0, r4 |
| 187 | mov r3, #0 |
| 188 | add r6, r0, #PG_DIR_SIZE |
| 189 | 1: str r3, [r0], #4 |
| 190 | str r3, [r0], #4 |
| 191 | str r3, [r0], #4 |
| 192 | str r3, [r0], #4 |
| 193 | teq r0, r6 |
| 194 | bne 1b |
| 195 | |
| 196 | #ifdef CONFIG_ARM_LPAE |
| 197 | /* |
| 198 | * Build the PGD table (first level) to point to the PMD table. A PGD |
| 199 | * entry is 64-bit wide. |
| 200 | */ |
| 201 | mov r0, r4 |
| 202 | add r3, r4, #0x1000 @ first PMD table address |
| 203 | orr r3, r3, #3 @ PGD block type |
| 204 | mov r6, #4 @ PTRS_PER_PGD |
| 205 | mov r7, #1 << (55 - 32) @ L_PGD_SWAPPER |
| 206 | 1: |
| 207 | #ifdef CONFIG_CPU_ENDIAN_BE8 |
| 208 | str r7, [r0], #4 @ set top PGD entry bits |
| 209 | str r3, [r0], #4 @ set bottom PGD entry bits |
| 210 | #else |
| 211 | str r3, [r0], #4 @ set bottom PGD entry bits |
| 212 | str r7, [r0], #4 @ set top PGD entry bits |
| 213 | #endif |
| 214 | add r3, r3, #0x1000 @ next PMD table |
| 215 | subs r6, r6, #1 |
| 216 | bne 1b |
| 217 | |
| 218 | add r4, r4, #0x1000 @ point to the PMD tables |
| 219 | #ifdef CONFIG_CPU_ENDIAN_BE8 |
| 220 | add r4, r4, #4 @ we only write the bottom word |
| 221 | #endif |
| 222 | #endif |
| 223 | |
| 224 | ldr r7, [r10, #PROCINFO_MM_MMUFLAGS] @ mm_mmuflags |
| 225 | |
| 226 | /* |
| 227 | * Create identity mapping to cater for __enable_mmu. |
| 228 | * This identity mapping will be removed by paging_init(). |
| 229 | */ |
| 230 | adr r0, __turn_mmu_on_loc |
| 231 | ldmia r0, {r3, r5, r6} |
| 232 | sub r0, r0, r3 @ virt->phys offset |
| 233 | add r5, r5, r0 @ phys __turn_mmu_on |
| 234 | add r6, r6, r0 @ phys __turn_mmu_on_end |
| 235 | mov r5, r5, lsr #SECTION_SHIFT |
| 236 | mov r6, r6, lsr #SECTION_SHIFT |
| 237 | |
| 238 | 1: orr r3, r7, r5, lsl #SECTION_SHIFT @ flags + kernel base |
| 239 | str r3, [r4, r5, lsl #PMD_ORDER] @ identity mapping |
| 240 | cmp r5, r6 |
| 241 | addlo r5, r5, #1 @ next section |
| 242 | blo 1b |
| 243 | |
| 244 | /* |
| 245 | * Map our RAM from the start to the end of the kernel .bss section. |
| 246 | */ |
| 247 | add r0, r4, #PAGE_OFFSET >> (SECTION_SHIFT - PMD_ORDER) |
| 248 | ldr r6, =(_end - 1) |
| 249 | orr r3, r8, r7 |
| 250 | add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER) |
| 251 | 1: str r3, [r0], #1 << PMD_ORDER |
| 252 | add r3, r3, #1 << SECTION_SHIFT |
| 253 | cmp r0, r6 |
| 254 | bls 1b |
| 255 | |
| 256 | #ifdef CONFIG_XIP_KERNEL |
| 257 | /* |
| 258 | * Map the kernel image separately as it is not located in RAM. |
| 259 | */ |
| 260 | #define XIP_START XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR) |
| 261 | mov r3, pc |
| 262 | mov r3, r3, lsr #SECTION_SHIFT |
| 263 | orr r3, r7, r3, lsl #SECTION_SHIFT |
| 264 | add r0, r4, #(XIP_START & 0xff000000) >> (SECTION_SHIFT - PMD_ORDER) |
| 265 | str r3, [r0, #((XIP_START & 0x00f00000) >> SECTION_SHIFT) << PMD_ORDER]! |
| 266 | ldr r6, =(_edata_loc - 1) |
| 267 | add r0, r0, #1 << PMD_ORDER |
| 268 | add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER) |
| 269 | 1: cmp r0, r6 |
| 270 | add r3, r3, #1 << SECTION_SHIFT |
| 271 | strls r3, [r0], #1 << PMD_ORDER |
| 272 | bls 1b |
| 273 | #endif |
| 274 | |
| 275 | /* |
| 276 | * Then map boot params address in r2 if specified. |
| 277 | * We map 2 sections in case the ATAGs/DTB crosses a section boundary. |
| 278 | */ |
| 279 | mov r0, r2, lsr #SECTION_SHIFT |
| 280 | movs r0, r0, lsl #SECTION_SHIFT |
| 281 | subne r3, r0, r8 |
| 282 | addne r3, r3, #PAGE_OFFSET |
| 283 | addne r3, r4, r3, lsr #(SECTION_SHIFT - PMD_ORDER) |
| 284 | orrne r6, r7, r0 |
| 285 | strne r6, [r3], #1 << PMD_ORDER |
| 286 | addne r6, r6, #1 << SECTION_SHIFT |
| 287 | strne r6, [r3] |
| 288 | |
| 289 | #if defined(CONFIG_ARM_LPAE) && defined(CONFIG_CPU_ENDIAN_BE8) |
| 290 | sub r4, r4, #4 @ Fixup page table pointer |
| 291 | @ for 64-bit descriptors |
| 292 | #endif |
| 293 | |
| 294 | #ifdef CONFIG_DEBUG_LL |
| 295 | #if !defined(CONFIG_DEBUG_ICEDCC) && !defined(CONFIG_DEBUG_SEMIHOSTING) |
| 296 | /* |
| 297 | * Map in IO space for serial debugging. |
| 298 | * This allows debug messages to be output |
| 299 | * via a serial console before paging_init. |
| 300 | */ |
| 301 | addruart r7, r3, r0 |
| 302 | |
| 303 | mov r3, r3, lsr #SECTION_SHIFT |
| 304 | mov r3, r3, lsl #PMD_ORDER |
| 305 | |
| 306 | add r0, r4, r3 |
| 307 | mov r3, r7, lsr #SECTION_SHIFT |
| 308 | ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags |
| 309 | orr r3, r7, r3, lsl #SECTION_SHIFT |
| 310 | #ifdef CONFIG_ARM_LPAE |
| 311 | mov r7, #1 << (54 - 32) @ XN |
| 312 | #ifdef CONFIG_CPU_ENDIAN_BE8 |
| 313 | str r7, [r0], #4 |
| 314 | str r3, [r0], #4 |
| 315 | #else |
| 316 | str r3, [r0], #4 |
| 317 | str r7, [r0], #4 |
| 318 | #endif |
| 319 | #else |
| 320 | orr r3, r3, #PMD_SECT_XN |
| 321 | str r3, [r0], #4 |
| 322 | #endif |
| 323 | |
| 324 | #else /* CONFIG_DEBUG_ICEDCC || CONFIG_DEBUG_SEMIHOSTING */ |
| 325 | /* we don't need any serial debugging mappings */ |
| 326 | ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags |
| 327 | #endif |
| 328 | |
| 329 | #if defined(CONFIG_ARCH_NETWINDER) || defined(CONFIG_ARCH_CATS) |
| 330 | /* |
| 331 | * If we're using the NetWinder or CATS, we also need to map |
| 332 | * in the 16550-type serial port for the debug messages |
| 333 | */ |
| 334 | add r0, r4, #0xff000000 >> (SECTION_SHIFT - PMD_ORDER) |
| 335 | orr r3, r7, #0x7c000000 |
| 336 | str r3, [r0] |
| 337 | #endif |
| 338 | #ifdef CONFIG_ARCH_RPC |
| 339 | /* |
| 340 | * Map in screen at 0x02000000 & SCREEN2_BASE |
| 341 | * Similar reasons here - for debug. This is |
| 342 | * only for Acorn RiscPC architectures. |
| 343 | */ |
| 344 | add r0, r4, #0x02000000 >> (SECTION_SHIFT - PMD_ORDER) |
| 345 | orr r3, r7, #0x02000000 |
| 346 | str r3, [r0] |
| 347 | add r0, r4, #0xd8000000 >> (SECTION_SHIFT - PMD_ORDER) |
| 348 | str r3, [r0] |
| 349 | #endif |
| 350 | #endif |
| 351 | #ifdef CONFIG_ARM_LPAE |
| 352 | sub r4, r4, #0x1000 @ point to the PGD table |
| 353 | #endif |
| 354 | ret lr |
| 355 | ENDPROC(__create_page_tables) |
| 356 | .ltorg |
| 357 | .align |
| 358 | __turn_mmu_on_loc: |
| 359 | .long . |
| 360 | .long __turn_mmu_on |
| 361 | .long __turn_mmu_on_end |
| 362 | |
| 363 | #if defined(CONFIG_SMP) |
| 364 | .text |
| 365 | .arm |
| 366 | ENTRY(secondary_startup_arm) |
| 367 | THUMB( badr r9, 1f ) @ Kernel is entered in ARM. |
| 368 | THUMB( bx r9 ) @ If this is a Thumb-2 kernel, |
| 369 | THUMB( .thumb ) @ switch to Thumb now. |
| 370 | THUMB(1: ) |
| 371 | ENTRY(secondary_startup) |
| 372 | /* |
| 373 | * Common entry point for secondary CPUs. |
| 374 | * |
| 375 | * Ensure that we're in SVC mode, and IRQs are disabled. Lookup |
| 376 | * the processor type - there is no need to check the machine type |
| 377 | * as it has already been validated by the primary processor. |
| 378 | */ |
| 379 | |
| 380 | ARM_BE8(setend be) @ ensure we are in BE8 mode |
| 381 | |
| 382 | #ifdef CONFIG_ARM_VIRT_EXT |
| 383 | bl __hyp_stub_install_secondary |
| 384 | #endif |
| 385 | safe_svcmode_maskall r9 |
| 386 | |
| 387 | mrc p15, 0, r9, c0, c0 @ get processor id |
| 388 | bl __lookup_processor_type |
| 389 | movs r10, r5 @ invalid processor? |
| 390 | moveq r0, #'p' @ yes, error 'p' |
| 391 | THUMB( it eq ) @ force fixup-able long branch encoding |
| 392 | beq __error_p |
| 393 | |
| 394 | /* |
| 395 | * Use the page tables supplied from __cpu_up. |
| 396 | */ |
| 397 | adr r4, __secondary_data |
| 398 | ldmia r4, {r5, r7, r12} @ address to jump to after |
| 399 | sub lr, r4, r5 @ mmu has been enabled |
| 400 | add r3, r7, lr |
| 401 | ldrd r4, [r3, #0] @ get secondary_data.pgdir |
| 402 | ARM_BE8(eor r4, r4, r5) @ Swap r5 and r4 in BE: |
| 403 | ARM_BE8(eor r5, r4, r5) @ it can be done in 3 steps |
| 404 | ARM_BE8(eor r4, r4, r5) @ without using a temp reg. |
| 405 | ldr r8, [r3, #8] @ get secondary_data.swapper_pg_dir |
| 406 | badr lr, __enable_mmu @ return address |
| 407 | mov r13, r12 @ __secondary_switched address |
| 408 | ldr r12, [r10, #PROCINFO_INITFUNC] |
| 409 | add r12, r12, r10 @ initialise processor |
| 410 | @ (return control reg) |
| 411 | ret r12 |
| 412 | ENDPROC(secondary_startup) |
| 413 | ENDPROC(secondary_startup_arm) |
| 414 | |
| 415 | /* |
| 416 | * r6 = &secondary_data |
| 417 | */ |
| 418 | ENTRY(__secondary_switched) |
| 419 | ldr sp, [r7, #12] @ get secondary_data.stack |
| 420 | mov fp, #0 |
| 421 | b secondary_start_kernel |
| 422 | ENDPROC(__secondary_switched) |
| 423 | |
| 424 | .align |
| 425 | |
| 426 | .type __secondary_data, %object |
| 427 | __secondary_data: |
| 428 | .long . |
| 429 | .long secondary_data |
| 430 | .long __secondary_switched |
| 431 | #endif /* defined(CONFIG_SMP) */ |
| 432 | |
| 433 | |
| 434 | |
| 435 | /* |
| 436 | * Setup common bits before finally enabling the MMU. Essentially |
| 437 | * this is just loading the page table pointer and domain access |
| 438 | * registers. All these registers need to be preserved by the |
| 439 | * processor setup function (or set in the case of r0) |
| 440 | * |
| 441 | * r0 = cp#15 control register |
| 442 | * r1 = machine ID |
| 443 | * r2 = atags or dtb pointer |
| 444 | * r4 = TTBR pointer (low word) |
| 445 | * r5 = TTBR pointer (high word if LPAE) |
| 446 | * r9 = processor ID |
| 447 | * r13 = *virtual* address to jump to upon completion |
| 448 | */ |
| 449 | __enable_mmu: |
| 450 | #if defined(CONFIG_ALIGNMENT_TRAP) && __LINUX_ARM_ARCH__ < 6 |
| 451 | orr r0, r0, #CR_A |
| 452 | #else |
| 453 | bic r0, r0, #CR_A |
| 454 | #endif |
| 455 | #ifdef CONFIG_CPU_DCACHE_DISABLE |
| 456 | bic r0, r0, #CR_C |
| 457 | #endif |
| 458 | #ifdef CONFIG_CPU_BPREDICT_DISABLE |
| 459 | bic r0, r0, #CR_Z |
| 460 | #endif |
| 461 | #ifdef CONFIG_CPU_ICACHE_DISABLE |
| 462 | bic r0, r0, #CR_I |
| 463 | #endif |
| 464 | #ifdef CONFIG_ARM_LPAE |
| 465 | mcrr p15, 0, r4, r5, c2 @ load TTBR0 |
| 466 | #else |
| 467 | mov r5, #DACR_INIT |
| 468 | mcr p15, 0, r5, c3, c0, 0 @ load domain access register |
| 469 | mcr p15, 0, r4, c2, c0, 0 @ load page table pointer |
| 470 | #endif |
| 471 | b __turn_mmu_on |
| 472 | ENDPROC(__enable_mmu) |
| 473 | |
| 474 | /* |
| 475 | * Enable the MMU. This completely changes the structure of the visible |
| 476 | * memory space. You will not be able to trace execution through this. |
| 477 | * If you have an enquiry about this, *please* check the linux-arm-kernel |
| 478 | * mailing list archives BEFORE sending another post to the list. |
| 479 | * |
| 480 | * r0 = cp#15 control register |
| 481 | * r1 = machine ID |
| 482 | * r2 = atags or dtb pointer |
| 483 | * r9 = processor ID |
| 484 | * r13 = *virtual* address to jump to upon completion |
| 485 | * |
| 486 | * other registers depend on the function called upon completion |
| 487 | */ |
| 488 | .align 5 |
| 489 | .pushsection .idmap.text, "ax" |
| 490 | ENTRY(__turn_mmu_on) |
| 491 | mov r0, r0 |
| 492 | instr_sync |
| 493 | mcr p15, 0, r0, c1, c0, 0 @ write control reg |
| 494 | mrc p15, 0, r3, c0, c0, 0 @ read id reg |
| 495 | instr_sync |
| 496 | mov r3, r3 |
| 497 | mov r3, r13 |
| 498 | ret r3 |
| 499 | __turn_mmu_on_end: |
| 500 | ENDPROC(__turn_mmu_on) |
| 501 | .popsection |
| 502 | |
| 503 | |
| 504 | #ifdef CONFIG_SMP_ON_UP |
| 505 | __HEAD |
| 506 | __fixup_smp: |
| 507 | and r3, r9, #0x000f0000 @ architecture version |
| 508 | teq r3, #0x000f0000 @ CPU ID supported? |
| 509 | bne __fixup_smp_on_up @ no, assume UP |
| 510 | |
| 511 | bic r3, r9, #0x00ff0000 |
| 512 | bic r3, r3, #0x0000000f @ mask 0xff00fff0 |
| 513 | mov r4, #0x41000000 |
| 514 | orr r4, r4, #0x0000b000 |
| 515 | orr r4, r4, #0x00000020 @ val 0x4100b020 |
| 516 | teq r3, r4 @ ARM 11MPCore? |
| 517 | reteq lr @ yes, assume SMP |
| 518 | |
| 519 | mrc p15, 0, r0, c0, c0, 5 @ read MPIDR |
| 520 | and r0, r0, #0xc0000000 @ multiprocessing extensions and |
| 521 | teq r0, #0x80000000 @ not part of a uniprocessor system? |
| 522 | bne __fixup_smp_on_up @ no, assume UP |
| 523 | |
| 524 | @ Core indicates it is SMP. Check for Aegis SOC where a single |
| 525 | @ Cortex-A9 CPU is present but SMP operations fault. |
| 526 | mov r4, #0x41000000 |
| 527 | orr r4, r4, #0x0000c000 |
| 528 | orr r4, r4, #0x00000090 |
| 529 | teq r3, r4 @ Check for ARM Cortex-A9 |
| 530 | retne lr @ Not ARM Cortex-A9, |
| 531 | |
| 532 | @ If a future SoC *does* use 0x0 as the PERIPH_BASE, then the |
| 533 | @ below address check will need to be #ifdef'd or equivalent |
| 534 | @ for the Aegis platform. |
| 535 | mrc p15, 4, r0, c15, c0 @ get SCU base address |
| 536 | teq r0, #0x0 @ '0' on actual UP A9 hardware |
| 537 | beq __fixup_smp_on_up @ So its an A9 UP |
| 538 | ldr r0, [r0, #4] @ read SCU Config |
| 539 | ARM_BE8(rev r0, r0) @ byteswap if big endian |
| 540 | and r0, r0, #0x3 @ number of CPUs |
| 541 | teq r0, #0x0 @ is 1? |
| 542 | retne lr |
| 543 | |
| 544 | __fixup_smp_on_up: |
| 545 | adr r0, 1f |
| 546 | ldmia r0, {r3 - r5} |
| 547 | sub r3, r0, r3 |
| 548 | add r4, r4, r3 |
| 549 | add r5, r5, r3 |
| 550 | b __do_fixup_smp_on_up |
| 551 | ENDPROC(__fixup_smp) |
| 552 | |
| 553 | .align |
| 554 | 1: .word . |
| 555 | .word __smpalt_begin |
| 556 | .word __smpalt_end |
| 557 | |
| 558 | .pushsection .data |
| 559 | .globl smp_on_up |
| 560 | smp_on_up: |
| 561 | ALT_SMP(.long 1) |
| 562 | ALT_UP(.long 0) |
| 563 | .popsection |
| 564 | #endif |
| 565 | |
| 566 | .text |
| 567 | __do_fixup_smp_on_up: |
| 568 | cmp r4, r5 |
| 569 | reths lr |
| 570 | ldmia r4!, {r0, r6} |
| 571 | ARM( str r6, [r0, r3] ) |
| 572 | THUMB( add r0, r0, r3 ) |
| 573 | #ifdef __ARMEB__ |
| 574 | THUMB( mov r6, r6, ror #16 ) @ Convert word order for big-endian. |
| 575 | #endif |
| 576 | THUMB( strh r6, [r0], #2 ) @ For Thumb-2, store as two halfwords |
| 577 | THUMB( mov r6, r6, lsr #16 ) @ to be robust against misaligned r3. |
| 578 | THUMB( strh r6, [r0] ) |
| 579 | b __do_fixup_smp_on_up |
| 580 | ENDPROC(__do_fixup_smp_on_up) |
| 581 | |
| 582 | ENTRY(fixup_smp) |
| 583 | stmfd sp!, {r4 - r6, lr} |
| 584 | mov r4, r0 |
| 585 | add r5, r0, r1 |
| 586 | mov r3, #0 |
| 587 | bl __do_fixup_smp_on_up |
| 588 | ldmfd sp!, {r4 - r6, pc} |
| 589 | ENDPROC(fixup_smp) |
| 590 | |
| 591 | #ifdef __ARMEB__ |
| 592 | #define LOW_OFFSET 0x4 |
| 593 | #define HIGH_OFFSET 0x0 |
| 594 | #else |
| 595 | #define LOW_OFFSET 0x0 |
| 596 | #define HIGH_OFFSET 0x4 |
| 597 | #endif |
| 598 | |
| 599 | #ifdef CONFIG_ARM_PATCH_PHYS_VIRT |
| 600 | |
| 601 | /* __fixup_pv_table - patch the stub instructions with the delta between |
| 602 | * PHYS_OFFSET and PAGE_OFFSET, which is assumed to be 16MiB aligned and |
| 603 | * can be expressed by an immediate shifter operand. The stub instruction |
| 604 | * has a form of '(add|sub) rd, rn, #imm'. |
| 605 | */ |
| 606 | __HEAD |
| 607 | __fixup_pv_table: |
| 608 | adr r0, 1f |
| 609 | ldmia r0, {r3-r7} |
| 610 | mvn ip, #0 |
| 611 | subs r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET |
| 612 | add r4, r4, r3 @ adjust table start address |
| 613 | add r5, r5, r3 @ adjust table end address |
| 614 | add r6, r6, r3 @ adjust __pv_phys_pfn_offset address |
| 615 | add r7, r7, r3 @ adjust __pv_offset address |
| 616 | mov r0, r8, lsr #PAGE_SHIFT @ convert to PFN |
| 617 | str r0, [r6] @ save computed PHYS_OFFSET to __pv_phys_pfn_offset |
| 618 | strcc ip, [r7, #HIGH_OFFSET] @ save to __pv_offset high bits |
| 619 | mov r6, r3, lsr #24 @ constant for add/sub instructions |
| 620 | teq r3, r6, lsl #24 @ must be 16MiB aligned |
| 621 | THUMB( it ne @ cross section branch ) |
| 622 | bne __error |
| 623 | str r3, [r7, #LOW_OFFSET] @ save to __pv_offset low bits |
| 624 | b __fixup_a_pv_table |
| 625 | ENDPROC(__fixup_pv_table) |
| 626 | |
| 627 | .align |
| 628 | 1: .long . |
| 629 | .long __pv_table_begin |
| 630 | .long __pv_table_end |
| 631 | 2: .long __pv_phys_pfn_offset |
| 632 | .long __pv_offset |
| 633 | |
| 634 | .text |
| 635 | __fixup_a_pv_table: |
| 636 | adr r0, 3f |
| 637 | ldr r6, [r0] |
| 638 | add r6, r6, r3 |
| 639 | ldr r0, [r6, #HIGH_OFFSET] @ pv_offset high word |
| 640 | ldr r6, [r6, #LOW_OFFSET] @ pv_offset low word |
| 641 | mov r6, r6, lsr #24 |
| 642 | cmn r0, #1 |
| 643 | #ifdef CONFIG_THUMB2_KERNEL |
| 644 | moveq r0, #0x200000 @ set bit 21, mov to mvn instruction |
| 645 | lsls r6, #24 |
| 646 | beq 2f |
| 647 | clz r7, r6 |
| 648 | lsr r6, #24 |
| 649 | lsl r6, r7 |
| 650 | bic r6, #0x0080 |
| 651 | lsrs r7, #1 |
| 652 | orrcs r6, #0x0080 |
| 653 | orr r6, r6, r7, lsl #12 |
| 654 | orr r6, #0x4000 |
| 655 | b 2f |
| 656 | 1: add r7, r3 |
| 657 | ldrh ip, [r7, #2] |
| 658 | ARM_BE8(rev16 ip, ip) |
| 659 | tst ip, #0x4000 |
| 660 | and ip, #0x8f00 |
| 661 | orrne ip, r6 @ mask in offset bits 31-24 |
| 662 | orreq ip, r0 @ mask in offset bits 7-0 |
| 663 | ARM_BE8(rev16 ip, ip) |
| 664 | strh ip, [r7, #2] |
| 665 | bne 2f |
| 666 | ldrh ip, [r7] |
| 667 | ARM_BE8(rev16 ip, ip) |
| 668 | bic ip, #0x20 |
| 669 | orr ip, ip, r0, lsr #16 |
| 670 | ARM_BE8(rev16 ip, ip) |
| 671 | strh ip, [r7] |
| 672 | 2: cmp r4, r5 |
| 673 | ldrcc r7, [r4], #4 @ use branch for delay slot |
| 674 | bcc 1b |
| 675 | bx lr |
| 676 | #else |
| 677 | #ifdef CONFIG_CPU_ENDIAN_BE8 |
| 678 | moveq r0, #0x00004000 @ set bit 22, mov to mvn instruction |
| 679 | #else |
| 680 | moveq r0, #0x400000 @ set bit 22, mov to mvn instruction |
| 681 | #endif |
| 682 | b 2f |
| 683 | 1: ldr ip, [r7, r3] |
| 684 | #ifdef CONFIG_CPU_ENDIAN_BE8 |
| 685 | @ in BE8, we load data in BE, but instructions still in LE |
| 686 | bic ip, ip, #0xff000000 |
| 687 | tst ip, #0x000f0000 @ check the rotation field |
| 688 | orrne ip, ip, r6, lsl #24 @ mask in offset bits 31-24 |
| 689 | biceq ip, ip, #0x00004000 @ clear bit 22 |
| 690 | orreq ip, ip, r0 @ mask in offset bits 7-0 |
| 691 | #else |
| 692 | bic ip, ip, #0x000000ff |
| 693 | tst ip, #0xf00 @ check the rotation field |
| 694 | orrne ip, ip, r6 @ mask in offset bits 31-24 |
| 695 | biceq ip, ip, #0x400000 @ clear bit 22 |
| 696 | orreq ip, ip, r0 @ mask in offset bits 7-0 |
| 697 | #endif |
| 698 | str ip, [r7, r3] |
| 699 | 2: cmp r4, r5 |
| 700 | ldrcc r7, [r4], #4 @ use branch for delay slot |
| 701 | bcc 1b |
| 702 | ret lr |
| 703 | #endif |
| 704 | ENDPROC(__fixup_a_pv_table) |
| 705 | |
| 706 | .align |
| 707 | 3: .long __pv_offset |
| 708 | |
| 709 | ENTRY(fixup_pv_table) |
| 710 | stmfd sp!, {r4 - r7, lr} |
| 711 | mov r3, #0 @ no offset |
| 712 | mov r4, r0 @ r0 = table start |
| 713 | add r5, r0, r1 @ r1 = table size |
| 714 | bl __fixup_a_pv_table |
| 715 | ldmfd sp!, {r4 - r7, pc} |
| 716 | ENDPROC(fixup_pv_table) |
| 717 | |
| 718 | .data |
| 719 | .globl __pv_phys_pfn_offset |
| 720 | .type __pv_phys_pfn_offset, %object |
| 721 | __pv_phys_pfn_offset: |
| 722 | .word 0 |
| 723 | .size __pv_phys_pfn_offset, . -__pv_phys_pfn_offset |
| 724 | |
| 725 | .globl __pv_offset |
| 726 | .type __pv_offset, %object |
| 727 | __pv_offset: |
| 728 | .quad 0 |
| 729 | .size __pv_offset, . -__pv_offset |
| 730 | #endif |
| 731 | |
| 732 | #include "head-common.S" |