1/*- 2 * Copyright (c) 2012-2014 Andrew Turner 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29#include "assym.s" 30#include "opt_kstack_pages.h" 31#include <sys/syscall.h> 32#include <machine/asm.h> 33#include <machine/armreg.h> 34#include <machine/hypervisor.h> 35#include <machine/param.h> 36#include <machine/pte.h> 37 38#define VIRT_BITS 39 39 40 .globl kernbase 41 .set kernbase, KERNBASE 42 43#define DEVICE_MEM 0 44#define NORMAL_UNCACHED 1 45#define NORMAL_MEM 2 46 47/* 48 * We assume: 49 * MMU on with an identity map, or off 50 * D-Cache: off 51 * I-Cache: on or off 52 * We are loaded at a 2MiB aligned address 53 */ 54 55 .text 56 .globl _start 57_start: 58 /* Drop to EL1 */ 59 bl drop_to_el1 60 61 /* 62 * Disable the MMU. We may have entered the kernel with it on and 63 * will need to update the tables later. If this has been set up 64 * with anything other than a VA == PA map then this will fail, 65 * but in this case the code to find where we are running from 66 * would have also failed. 67 */ 68 dsb sy 69 mrs x2, sctlr_el1 70 bic x2, x2, SCTLR_M 71 msr sctlr_el1, x2 72 isb 73 74 /* Set the context id */ 75 msr contextidr_el1, xzr 76 77 /* Get the virt -> phys offset */ 78 bl get_virt_delta 79 80 /* 81 * At this point: 82 * x29 = PA - VA 83 * x28 = Our physical load address 84 */ 85 86 /* Create the page tables */ 87 bl create_pagetables 88 89 /* 90 * At this point: 91 * x27 = TTBR0 table 92 * x26 = TTBR1 table 93 */ 94 95 /* Enable the mmu */ 96 bl start_mmu 97 98 /* Jump to the virtual address space */ 99 ldr x15, .Lvirtdone 100 br x15 101 102virtdone: 103 /* 104 * Now that we are in virtual address space, 105 * we don't need the identity mapping in TTBR0 and 106 * can set the TCR to a more useful value. 107 */ 108 ldr x2, tcr 109 mrs x3, id_aa64mmfr0_el1 110 bfi x2, x3, #32, #3 111 msr tcr_el1, x2 112 113 /* Set up the stack */ 114 adr x25, initstack_end 115 mov sp, x25 116 sub sp, sp, #PCB_SIZE 117 118 /* Zero the BSS */ 119 ldr x15, .Lbss 120 ldr x14, .Lend 1211: 122 str xzr, [x15], #8 123 cmp x15, x14 124 b.lo 1b 125 126 /* Backup the module pointer */ 127 mov x1, x0 128 129 /* Make the page table base a virtual address */ 130 sub x26, x26, x29 131 132 sub sp, sp, #(64 * 4) 133 mov x0, sp 134 135 /* Degate the delda so it is VA -> PA */ 136 neg x29, x29 137 138 str x1, [x0] /* modulep */ 139 str x26, [x0, 8] /* kern_l1pt */ 140 str x29, [x0, 16] /* kern_delta */ 141 str x25, [x0, 24] /* kern_stack */ 142 143 /* trace back starts here */ 144 mov fp, #0 145 /* Branch to C code */ 146 bl initarm 147 bl mi_startup 148 149 /* We should not get here */ 150 brk 0 151 152 .align 3 153.Lvirtdone: 154 .quad virtdone 155.Lbss: 156 .quad __bss_start 157.Lend: 158 .quad _end 159 160#ifdef SMP 161/* 162 * mpentry(unsigned long) 163 * 164 * Called by a core when it is being brought online. 165 * The data in x0 is passed straight to init_secondary. 166 */ 167ENTRY(mpentry) 168 /* Disable interrupts */ 169 msr daifset, #2 170 171 /* Drop to EL1 */ 172 bl drop_to_el1 173 174 /* Set the context id */ 175 msr contextidr_el1, x1 176 177 /* Load the kernel page table */ 178 adr x26, pagetable_l1_ttbr1 179 /* Load the identity page table */ 180 adr x27, pagetable_l0_ttbr0 181 182 /* Enable the mmu */ 183 bl start_mmu 184 185 /* Jump to the virtual address space */ 186 ldr x15, =mp_virtdone 187 br x15 188 189mp_virtdone: 190 /* 191 * Now that we are in virtual address space, 192 * we don't need the identity mapping in TTBR0 and 193 * can set the TCR to a more useful value. 194 */ 195 ldr x2, tcr 196 mrs x3, id_aa64mmfr0_el1 197 bfi x2, x3, #32, #3 198 msr tcr_el1, x2 199 200 ldr x4, =secondary_stacks 201 mov x5, #(PAGE_SIZE * KSTACK_PAGES) 202 mul x5, x0, x5 203 add sp, x4, x5 204 205 b init_secondary 206END(mpentry) 207#endif 208 209/* 210 * If we are started in EL2, configure the required hypervisor 211 * registers and drop to EL1. 212 */ 213drop_to_el1: 214 mrs x1, CurrentEL 215 lsr x1, x1, #2 216 cmp x1, #0x2 217 b.eq 1f 218 ret 2191: 220 /* Configure the Hypervisor */ 221 mov x2, #(HCR_RW) 222 msr hcr_el2, x2 223 224 /* Load the Virtualization Process ID Register */ 225 mrs x2, midr_el1 226 msr vpidr_el2, x2 227 228 /* Load the Virtualization Multiprocess ID Register */ 229 mrs x2, mpidr_el1 230 msr vmpidr_el2, x2 231 232 /* Set the bits that need to be 1 in sctlr_el1 */ 233 ldr x2, .Lsctlr_res1 234 msr sctlr_el1, x2 235 236 /* Don't trap to EL2 for exceptions */ 237 mov x2, #CPTR_RES1 238 msr cptr_el2, x2 239 240 /* Don't trap to EL2 for CP15 traps */ 241 msr hstr_el2, xzr 242 243 /* Enable access to the physical timers at EL1 */ 244 mrs x2, cnthctl_el2 245 orr x2, x2, #(CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN) 246 msr cnthctl_el2, x2 247 248 /* Set the counter offset to a known value */ 249 msr cntvoff_el2, xzr 250 251 /* Hypervisor trap functions */ 252 adr x2, hyp_vectors 253 msr vbar_el2, x2 254 255 mov x2, #(PSR_F | PSR_I | PSR_A | PSR_D | PSR_M_EL1h) 256 msr spsr_el2, x2 257 258 /* Configure GICv3 CPU interface */ 259 mrs x2, id_aa64pfr0_el1 260 /* Extract GIC bits from the register */ 261 ubfx x2, x2, #ID_AA64PFR0_GIC_SHIFT, #ID_AA64PFR0_GIC_BITS 262 /* GIC[3:0] == 0001 - GIC CPU interface via special regs. supported */ 263 cmp x2, #(ID_AA64PFR0_GIC_CPUIF_EN >> ID_AA64PFR0_GIC_SHIFT) 264 b.ne 2f 265 266 mrs x2, icc_sre_el2 267 orr x2, x2, #ICC_SRE_EL2_EN /* Enable access from insecure EL1 */ 268 msr icc_sre_el2, x2 2692: 270 271 /* Set the address to return to our return address */ 272 msr elr_el2, x30 273 isb 274 275 eret 276 277 .align 3 278.Lsctlr_res1: 279 .quad SCTLR_RES1 280 281#define VECT_EMPTY \ 282 .align 7; \ 283 1: b 1b 284 285 .align 11 286hyp_vectors: 287 VECT_EMPTY /* Synchronous EL2t */ 288 VECT_EMPTY /* IRQ EL2t */ 289 VECT_EMPTY /* FIQ EL2t */ 290 VECT_EMPTY /* Error EL2t */ 291 292 VECT_EMPTY /* Synchronous EL2h */ 293 VECT_EMPTY /* IRQ EL2h */ 294 VECT_EMPTY /* FIQ EL2h */ 295 VECT_EMPTY /* Error EL2h */ 296 297 VECT_EMPTY /* Synchronous 64-bit EL1 */ 298 VECT_EMPTY /* IRQ 64-bit EL1 */ 299 VECT_EMPTY /* FIQ 64-bit EL1 */ 300 VECT_EMPTY /* Error 64-bit EL1 */ 301 302 VECT_EMPTY /* Synchronous 32-bit EL1 */ 303 VECT_EMPTY /* IRQ 32-bit EL1 */ 304 VECT_EMPTY /* FIQ 32-bit EL1 */ 305 VECT_EMPTY /* Error 32-bit EL1 */ 306 307/* 308 * Get the delta between the physical address we were loaded to and the 309 * virtual address we expect to run from. This is used when building the 310 * initial page table. 311 */ 312get_virt_delta: 313 /* Load the physical address of virt_map */ 314 adr x29, virt_map 315 /* Load the virtual address of virt_map stored in virt_map */ 316 ldr x28, [x29] 317 /* Find PA - VA as PA' = VA' - VA + PA = VA' + (PA - VA) = VA' + x29 */ 318 sub x29, x29, x28 319 /* Find the load address for the kernel */ 320 mov x28, #(KERNBASE) 321 add x28, x28, x29 322 ret 323 324 .align 3 325virt_map: 326 .quad virt_map 327 328/* 329 * This builds the page tables containing the identity map, and the kernel 330 * virtual map. 331 * 332 * It relys on: 333 * We were loaded to an address that is on a 2MiB boundary 334 * All the memory must not cross a 1GiB boundaty 335 * x28 contains the physical address we were loaded from 336 * 337 * TODO: This is out of date. 338 * There are at least 5 pages before that address for the page tables 339 * The pages used are: 340 * - The identity (PA = VA) table (TTBR0) 341 * - The Kernel L1 table (TTBR1)(not yet) 342 * - The PA != VA L2 table to jump into (not yet) 343 * - The FDT L2 table (not yet) 344 */ 345create_pagetables: 346 /* Save the Link register */ 347 mov x5, x30 348 349 /* Clean the page table */ 350 adr x6, pagetable 351 mov x26, x6 352 adr x27, pagetable_end 3531: 354 stp xzr, xzr, [x6], #16 355 stp xzr, xzr, [x6], #16 356 stp xzr, xzr, [x6], #16 357 stp xzr, xzr, [x6], #16 358 cmp x6, x27 359 b.lo 1b 360 361 /* 362 * Build the TTBR1 maps. 363 */ 364 365 /* Find the size of the kernel */ 366 mov x6, #(KERNBASE) 367 ldr x7, .Lend 368 /* Find the end - begin */ 369 sub x8, x7, x6 370 /* Get the number of l2 pages to allocate, rounded down */ 371 lsr x10, x8, #(L2_SHIFT) 372 /* Add 8 MiB for any rounding above and the module data */ 373 add x10, x10, #4 374 375 /* Create the kernel space L2 table */ 376 mov x6, x26 377 mov x7, #NORMAL_MEM 378 mov x8, #(KERNBASE & L2_BLOCK_MASK) 379 mov x9, x28 380 bl build_l2_block_pagetable 381 382 /* Move to the l1 table */ 383 add x26, x26, #PAGE_SIZE 384 385 /* Link the l1 -> l2 table */ 386 mov x9, x6 387 mov x6, x26 388 bl link_l1_pagetable 389 390 391 /* 392 * Build the TTBR0 maps. 393 */ 394 add x27, x26, #PAGE_SIZE 395 396 mov x6, x27 /* The initial page table */ 397#if defined(SOCDEV_PA) && defined(SOCDEV_VA) 398 /* Create a table for the UART */ 399 mov x7, #DEVICE_MEM 400 mov x8, #(SOCDEV_VA) /* VA start */ 401 mov x9, #(SOCDEV_PA) /* PA start */ 402 mov x10, #1 403 bl build_l1_block_pagetable 404#endif 405 406 /* Create the VA = PA map */ 407 mov x7, #NORMAL_UNCACHED /* Uncached as it's only needed early on */ 408 mov x9, x27 409 mov x8, x9 /* VA start (== PA start) */ 410 mov x10, #1 411 bl build_l1_block_pagetable 412 413 /* Move to the l0 table */ 414 add x27, x27, #PAGE_SIZE 415 416 /* Link the l0 -> l1 table */ 417 mov x9, x6 418 mov x6, x27 419 bl link_l0_pagetable 420 421 /* Restore the Link register */ 422 mov x30, x5 423 ret 424 425/* 426 * Builds an L0 -> L1 table descriptor 427 * 428 * This is a link for a 512GiB block of memory with up to 1GiB regions mapped 429 * within it by build_l1_block_pagetable. 430 * 431 * x6 = L0 table 432 * x8 = Virtual Address 433 * x9 = L1 PA (trashed) 434 * x11, x12 and x13 are trashed 435 */ 436link_l0_pagetable: 437 /* 438 * Link an L0 -> L1 table entry. 439 */ 440 /* Find the table index */ 441 lsr x11, x8, #L0_SHIFT 442 and x11, x11, #Ln_ADDR_MASK 443 444 /* Build the L0 block entry */ 445 mov x12, #L0_TABLE 446 447 /* Only use the output address bits */ 448 lsr x9, x9, #12 449 orr x12, x12, x9, lsl #12 450 451 /* Store the entry */ 452 str x12, [x6, x11, lsl #3] 453 454 ret 455 456/* 457 * Builds an L1 -> L2 table descriptor 458 * 459 * This is a link for a 1GiB block of memory with up to 2MiB regions mapped 460 * within it by build_l2_block_pagetable. 461 * 462 * x6 = L1 table 463 * x8 = Virtual Address 464 * x9 = L2 PA (trashed) 465 * x11, x12 and x13 are trashed 466 */ 467link_l1_pagetable: 468 /* 469 * Link an L1 -> L2 table entry. 470 */ 471 /* Find the table index */ 472 lsr x11, x8, #L1_SHIFT 473 and x11, x11, #Ln_ADDR_MASK 474 475 /* Build the L1 block entry */ 476 mov x12, #L1_TABLE 477 478 /* Only use the output address bits */ 479 lsr x9, x9, #12 480 orr x12, x12, x9, lsl #12 481 482 /* Store the entry */ 483 str x12, [x6, x11, lsl #3] 484 485 ret 486 487/* 488 * Builds count 1 GiB page table entry 489 * x6 = L1 table 490 * x7 = Type (0 = Device, 1 = Normal) 491 * x8 = VA start 492 * x9 = PA start (trashed) 493 * x10 = Entry count (TODO) 494 * x11, x12 and x13 are trashed 495 */ 496build_l1_block_pagetable: 497 /* 498 * Build the L1 table entry. 499 */ 500 /* Find the table index */ 501 lsr x11, x8, #L1_SHIFT 502 and x11, x11, #Ln_ADDR_MASK 503 504 /* Build the L1 block entry */ 505 lsl x12, x7, #2 506 orr x12, x12, #L1_BLOCK 507 orr x12, x12, #(ATTR_AF) 508#ifdef SMP 509 orr x12, x12, ATTR_SH(ATTR_SH_IS) 510#endif 511 512 /* Only use the output address bits */ 513 lsr x9, x9, #L1_SHIFT 514 515 /* Set the physical address for this virtual address */ 5161: orr x12, x12, x9, lsl #L1_SHIFT 517 518 /* Store the entry */ 519 str x12, [x6, x11, lsl #3] 520 521 /* Clear the address bits */ 522 and x12, x12, #ATTR_MASK_L 523 524 sub x10, x10, #1 525 add x11, x11, #1 526 add x9, x9, #1 527 cbnz x10, 1b 528 5292: ret 530 531/* 532 * Builds count 2 MiB page table entry 533 * x6 = L2 table 534 * x7 = Type (0 = Device, 1 = Normal) 535 * x8 = VA start 536 * x9 = PA start (trashed) 537 * x10 = Entry count (TODO) 538 * x11, x12 and x13 are trashed 539 */ 540build_l2_block_pagetable: 541 /* 542 * Build the L2 table entry. 543 */ 544 /* Find the table index */ 545 lsr x11, x8, #L2_SHIFT 546 and x11, x11, #Ln_ADDR_MASK 547 548 /* Build the L2 block entry */ 549 lsl x12, x7, #2 550 orr x12, x12, #L2_BLOCK 551 orr x12, x12, #(ATTR_AF) 552#ifdef SMP 553 orr x12, x12, ATTR_SH(ATTR_SH_IS) 554#endif 555 556 /* Only use the output address bits */ 557 lsr x9, x9, #L2_SHIFT 558 559 /* Set the physical address for this virtual address */ 5601: orr x12, x12, x9, lsl #L2_SHIFT 561 562 /* Store the entry */ 563 str x12, [x6, x11, lsl #3] 564 565 /* Clear the address bits */ 566 and x12, x12, #ATTR_MASK_L 567 568 sub x10, x10, #1 569 add x11, x11, #1 570 add x9, x9, #1 571 cbnz x10, 1b 572 5732: ret 574 575start_mmu: 576 dsb sy 577 578 /* Load the exception vectors */ 579 ldr x2, =exception_vectors 580 msr vbar_el1, x2 581 582 /* Load ttbr0 and ttbr1 */ 583 msr ttbr0_el1, x27 584 msr ttbr1_el1, x26 585 isb 586 587 /* Clear the Monitor Debug System control register */ 588 msr mdscr_el1, xzr 589 590 /* Invalidate the TLB */ 591 tlbi vmalle1is 592 593 ldr x2, mair 594 msr mair_el1, x2 595 596 /* 597 * Setup TCR according to PARange bits from ID_AA64MMFR0_EL1. 598 * Some machines have physical memory mapped >512GiB, which can not 599 * be identity-mapped using the default 39 VA bits. Thus, use 600 * 48 VA bits for now and switch back to 39 after the VA jump. 601 */ 602 ldr x2, tcr_early 603 mrs x3, id_aa64mmfr0_el1 604 bfi x2, x3, #32, #3 605 msr tcr_el1, x2 606 607 /* Setup SCTLR */ 608 ldr x2, sctlr_set 609 ldr x3, sctlr_clear 610 mrs x1, sctlr_el1 611 bic x1, x1, x3 /* Clear the required bits */ 612 orr x1, x1, x2 /* Set the required bits */ 613 msr sctlr_el1, x1 614 isb 615 616 ret 617 618 .align 3 619mair: 620 /* Device Normal, no cache Normal, write-back */ 621 .quad MAIR_ATTR(0x00, 0) | MAIR_ATTR(0x44, 1) | MAIR_ATTR(0xff, 2) 622tcr: 623 .quad (TCR_TxSZ(64 - VIRT_BITS) | TCR_ASID_16 | TCR_TG1_4K | \ 624 TCR_CACHE_ATTRS | TCR_SMP_ATTRS) 625tcr_early: 626 .quad (TCR_T1SZ(64 - VIRT_BITS) | TCR_T0SZ(64 - 48) | \ 627 TCR_ASID_16 | TCR_TG1_4K | TCR_CACHE_ATTRS | TCR_SMP_ATTRS) 628sctlr_set: 629 /* Bits to set */ 630 .quad (SCTLR_UCI | SCTLR_nTWE | SCTLR_nTWI | SCTLR_UCT | SCTLR_DZE | \ 631 SCTLR_I | SCTLR_SED | SCTLR_C | SCTLR_M) 632sctlr_clear: 633 /* Bits to clear */ 634 .quad (SCTLR_EE | SCTLR_EOE | SCTLR_WXN | SCTLR_UMA | SCTLR_ITD | \ 635 SCTLR_THEE | SCTLR_CP15BEN | SCTLR_SA0 | SCTLR_SA | SCTLR_A) 636 637 .globl abort 638abort: 639 b abort 640 641 //.section .init_pagetable 642 .align 12 /* 4KiB aligned */ 643 /* 644 * 3 initial tables (in the following order): 645 * L2 for kernel (High addresses) 646 * L1 for kernel 647 * L1 for user (Low addresses) 648 */ 649pagetable: 650 .space PAGE_SIZE 651pagetable_l1_ttbr1: 652 .space PAGE_SIZE 653pagetable_l1_ttbr0: 654 .space PAGE_SIZE 655pagetable_l0_ttbr0: 656 .space PAGE_SIZE 657pagetable_end: 658 659el2_pagetable: 660 .space PAGE_SIZE 661 662 .globl init_pt_va 663init_pt_va: 664 .quad pagetable /* XXX: Keep page tables VA */ 665 666 .align 4 667initstack: 668 .space (PAGE_SIZE * KSTACK_PAGES) 669initstack_end: 670 671 672ENTRY(sigcode) 673 mov x0, sp 674 add x0, x0, #SF_UC 675 6761: 677 mov x8, #SYS_sigreturn 678 svc 0 679 680 /* sigreturn failed, exit */ 681 mov x8, #SYS_exit 682 svc 0 683 684 b 1b 685END(sigcode) 686 /* This may be copied to the stack, keep it 16-byte aligned */ 687 .align 3 688esigcode: 689 690 .data 691 .align 3 692 .global szsigcode 693szsigcode: 694 .quad esigcode - sigcode 695