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Diffstat (limited to 'arch/arm64/mm/proc.S')
| -rw-r--r-- | arch/arm64/mm/proc.S | 475 |
1 files changed, 475 insertions, 0 deletions
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S new file mode 100644 index 000000000..ec6aa1863 --- /dev/null +++ b/arch/arm64/mm/proc.S @@ -0,0 +1,475 @@ +/* + * Based on arch/arm/mm/proc.S + * + * Copyright (C) 2001 Deep Blue Solutions Ltd. + * Copyright (C) 2012 ARM Ltd. + * Author: Catalin Marinas <catalin.marinas@arm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/init.h> +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/asm-offsets.h> +#include <asm/hwcap.h> +#include <asm/pgtable.h> +#include <asm/pgtable-hwdef.h> +#include <asm/cpufeature.h> +#include <asm/alternative.h> + +#ifdef CONFIG_ARM64_64K_PAGES +#define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K +#elif defined(CONFIG_ARM64_16K_PAGES) +#define TCR_TG_FLAGS TCR_TG0_16K | TCR_TG1_16K +#else /* CONFIG_ARM64_4K_PAGES */ +#define TCR_TG_FLAGS TCR_TG0_4K | TCR_TG1_4K +#endif + +#ifdef CONFIG_RANDOMIZE_BASE +#define TCR_KASLR_FLAGS TCR_NFD1 +#else +#define TCR_KASLR_FLAGS 0 +#endif + +#define TCR_SMP_FLAGS TCR_SHARED + +/* PTWs cacheable, inner/outer WBWA */ +#define TCR_CACHE_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA + +#define MAIR(attr, mt) ((attr) << ((mt) * 8)) + +/* + * cpu_do_idle() + * + * Idle the processor (wait for interrupt). + */ +ENTRY(cpu_do_idle) + dsb sy // WFI may enter a low-power mode + wfi + ret +ENDPROC(cpu_do_idle) + +#ifdef CONFIG_CPU_PM +/** + * cpu_do_suspend - save CPU registers context + * + * x0: virtual address of context pointer + */ +ENTRY(cpu_do_suspend) + mrs x2, tpidr_el0 + mrs x3, tpidrro_el0 + mrs x4, contextidr_el1 + mrs x5, osdlr_el1 + mrs x6, cpacr_el1 + mrs x7, tcr_el1 + mrs x8, vbar_el1 + mrs x9, mdscr_el1 + mrs x10, oslsr_el1 + mrs x11, sctlr_el1 +alternative_if_not ARM64_HAS_VIRT_HOST_EXTN + mrs x12, tpidr_el1 +alternative_else + mrs x12, tpidr_el2 +alternative_endif + mrs x13, sp_el0 + stp x2, x3, [x0] + stp x4, x5, [x0, #16] + stp x6, x7, [x0, #32] + stp x8, x9, [x0, #48] + stp x10, x11, [x0, #64] + stp x12, x13, [x0, #80] + ret +ENDPROC(cpu_do_suspend) + +/** + * cpu_do_resume - restore CPU register context + * + * x0: Address of context pointer + */ + .pushsection ".idmap.text", "awx" +ENTRY(cpu_do_resume) + ldp x2, x3, [x0] + ldp x4, x5, [x0, #16] + ldp x6, x8, [x0, #32] + ldp x9, x10, [x0, #48] + ldp x11, x12, [x0, #64] + ldp x13, x14, [x0, #80] + msr tpidr_el0, x2 + msr tpidrro_el0, x3 + msr contextidr_el1, x4 + msr cpacr_el1, x6 + + /* Don't change t0sz here, mask those bits when restoring */ + mrs x7, tcr_el1 + bfi x8, x7, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH + + msr tcr_el1, x8 + msr vbar_el1, x9 + + /* + * __cpu_setup() cleared MDSCR_EL1.MDE and friends, before unmasking + * debug exceptions. By restoring MDSCR_EL1 here, we may take a debug + * exception. Mask them until local_daif_restore() in cpu_suspend() + * resets them. + */ + disable_daif + msr mdscr_el1, x10 + + msr sctlr_el1, x12 +alternative_if_not ARM64_HAS_VIRT_HOST_EXTN + msr tpidr_el1, x13 +alternative_else + msr tpidr_el2, x13 +alternative_endif + msr sp_el0, x14 + /* + * Restore oslsr_el1 by writing oslar_el1 + */ + msr osdlr_el1, x5 + ubfx x11, x11, #1, #1 + msr oslar_el1, x11 + reset_pmuserenr_el0 x0 // Disable PMU access from EL0 + +alternative_if ARM64_HAS_RAS_EXTN + msr_s SYS_DISR_EL1, xzr +alternative_else_nop_endif + + isb + ret +ENDPROC(cpu_do_resume) + .popsection +#endif + +/* + * cpu_do_switch_mm(pgd_phys, tsk) + * + * Set the translation table base pointer to be pgd_phys. + * + * - pgd_phys - physical address of new TTB + */ +ENTRY(cpu_do_switch_mm) + mrs x2, ttbr1_el1 + mmid x1, x1 // get mm->context.id + phys_to_ttbr x3, x0 +#ifdef CONFIG_ARM64_SW_TTBR0_PAN + bfi x3, x1, #48, #16 // set the ASID field in TTBR0 +#endif + bfi x2, x1, #48, #16 // set the ASID + msr ttbr1_el1, x2 // in TTBR1 (since TCR.A1 is set) + isb + msr ttbr0_el1, x3 // now update TTBR0 + isb + b post_ttbr_update_workaround // Back to C code... +ENDPROC(cpu_do_switch_mm) + + .pushsection ".idmap.text", "awx" + +.macro __idmap_cpu_set_reserved_ttbr1, tmp1, tmp2 + adrp \tmp1, empty_zero_page + phys_to_ttbr \tmp2, \tmp1 + msr ttbr1_el1, \tmp2 + isb + tlbi vmalle1 + dsb nsh + isb +.endm + +/* + * void idmap_cpu_replace_ttbr1(phys_addr_t new_pgd) + * + * This is the low-level counterpart to cpu_replace_ttbr1, and should not be + * called by anything else. It can only be executed from a TTBR0 mapping. + */ +ENTRY(idmap_cpu_replace_ttbr1) + save_and_disable_daif flags=x2 + + __idmap_cpu_set_reserved_ttbr1 x1, x3 + + phys_to_ttbr x3, x0 + msr ttbr1_el1, x3 + isb + + restore_daif x2 + + ret +ENDPROC(idmap_cpu_replace_ttbr1) + .popsection + +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 + .pushsection ".idmap.text", "awx" + + .macro __idmap_kpti_get_pgtable_ent, type + dc cvac, cur_\()\type\()p // Ensure any existing dirty + dmb sy // lines are written back before + ldr \type, [cur_\()\type\()p] // loading the entry + tbz \type, #0, skip_\()\type // Skip invalid and + tbnz \type, #11, skip_\()\type // non-global entries + .endm + + .macro __idmap_kpti_put_pgtable_ent_ng, type + orr \type, \type, #PTE_NG // Same bit for blocks and pages + str \type, [cur_\()\type\()p] // Update the entry and ensure + dmb sy // that it is visible to all + dc civac, cur_\()\type\()p // CPUs. + .endm + +/* + * void __kpti_install_ng_mappings(int cpu, int num_cpus, phys_addr_t swapper) + * + * Called exactly once from stop_machine context by each CPU found during boot. + */ +__idmap_kpti_flag: + .long 1 +ENTRY(idmap_kpti_install_ng_mappings) + cpu .req w0 + num_cpus .req w1 + swapper_pa .req x2 + swapper_ttb .req x3 + flag_ptr .req x4 + cur_pgdp .req x5 + end_pgdp .req x6 + pgd .req x7 + cur_pudp .req x8 + end_pudp .req x9 + pud .req x10 + cur_pmdp .req x11 + end_pmdp .req x12 + pmd .req x13 + cur_ptep .req x14 + end_ptep .req x15 + pte .req x16 + + mrs swapper_ttb, ttbr1_el1 + adr flag_ptr, __idmap_kpti_flag + + cbnz cpu, __idmap_kpti_secondary + + /* We're the boot CPU. Wait for the others to catch up */ + sevl +1: wfe + ldaxr w18, [flag_ptr] + eor w18, w18, num_cpus + cbnz w18, 1b + + /* We need to walk swapper, so turn off the MMU. */ + pre_disable_mmu_workaround + mrs x18, sctlr_el1 + bic x18, x18, #SCTLR_ELx_M + msr sctlr_el1, x18 + isb + + /* Everybody is enjoying the idmap, so we can rewrite swapper. */ + /* PGD */ + mov cur_pgdp, swapper_pa + add end_pgdp, cur_pgdp, #(PTRS_PER_PGD * 8) +do_pgd: __idmap_kpti_get_pgtable_ent pgd + tbnz pgd, #1, walk_puds +next_pgd: + __idmap_kpti_put_pgtable_ent_ng pgd +skip_pgd: + add cur_pgdp, cur_pgdp, #8 + cmp cur_pgdp, end_pgdp + b.ne do_pgd + + /* Publish the updated tables and nuke all the TLBs */ + dsb sy + tlbi vmalle1is + dsb ish + isb + + /* We're done: fire up the MMU again */ + mrs x18, sctlr_el1 + orr x18, x18, #SCTLR_ELx_M + msr sctlr_el1, x18 + isb + + /* + * Invalidate the local I-cache so that any instructions fetched + * speculatively from the PoC are discarded, since they may have + * been dynamically patched at the PoU. + */ + ic iallu + dsb nsh + isb + + /* Set the flag to zero to indicate that we're all done */ + str wzr, [flag_ptr] + ret + + /* PUD */ +walk_puds: + .if CONFIG_PGTABLE_LEVELS > 3 + pte_to_phys cur_pudp, pgd + add end_pudp, cur_pudp, #(PTRS_PER_PUD * 8) +do_pud: __idmap_kpti_get_pgtable_ent pud + tbnz pud, #1, walk_pmds +next_pud: + __idmap_kpti_put_pgtable_ent_ng pud +skip_pud: + add cur_pudp, cur_pudp, 8 + cmp cur_pudp, end_pudp + b.ne do_pud + b next_pgd + .else /* CONFIG_PGTABLE_LEVELS <= 3 */ + mov pud, pgd + b walk_pmds +next_pud: + b next_pgd + .endif + + /* PMD */ +walk_pmds: + .if CONFIG_PGTABLE_LEVELS > 2 + pte_to_phys cur_pmdp, pud + add end_pmdp, cur_pmdp, #(PTRS_PER_PMD * 8) +do_pmd: __idmap_kpti_get_pgtable_ent pmd + tbnz pmd, #1, walk_ptes +next_pmd: + __idmap_kpti_put_pgtable_ent_ng pmd +skip_pmd: + add cur_pmdp, cur_pmdp, #8 + cmp cur_pmdp, end_pmdp + b.ne do_pmd + b next_pud + .else /* CONFIG_PGTABLE_LEVELS <= 2 */ + mov pmd, pud + b walk_ptes +next_pmd: + b next_pud + .endif + + /* PTE */ +walk_ptes: + pte_to_phys cur_ptep, pmd + add end_ptep, cur_ptep, #(PTRS_PER_PTE * 8) +do_pte: __idmap_kpti_get_pgtable_ent pte + __idmap_kpti_put_pgtable_ent_ng pte +skip_pte: + add cur_ptep, cur_ptep, #8 + cmp cur_ptep, end_ptep + b.ne do_pte + b next_pmd + + /* Secondary CPUs end up here */ +__idmap_kpti_secondary: + /* Uninstall swapper before surgery begins */ + __idmap_cpu_set_reserved_ttbr1 x18, x17 + + /* Increment the flag to let the boot CPU we're ready */ +1: ldxr w18, [flag_ptr] + add w18, w18, #1 + stxr w17, w18, [flag_ptr] + cbnz w17, 1b + + /* Wait for the boot CPU to finish messing around with swapper */ + sevl +1: wfe + ldxr w18, [flag_ptr] + cbnz w18, 1b + + /* All done, act like nothing happened */ + msr ttbr1_el1, swapper_ttb + isb + ret + + .unreq cpu + .unreq num_cpus + .unreq swapper_pa + .unreq swapper_ttb + .unreq flag_ptr + .unreq cur_pgdp + .unreq end_pgdp + .unreq pgd + .unreq cur_pudp + .unreq end_pudp + .unreq pud + .unreq cur_pmdp + .unreq end_pmdp + .unreq pmd + .unreq cur_ptep + .unreq end_ptep + .unreq pte +ENDPROC(idmap_kpti_install_ng_mappings) + .popsection +#endif + +/* + * __cpu_setup + * + * Initialise the processor for turning the MMU on. Return in x0 the + * value of the SCTLR_EL1 register. + */ + .pushsection ".idmap.text", "awx" +ENTRY(__cpu_setup) + tlbi vmalle1 // Invalidate local TLB + dsb nsh + + mov x0, #3 << 20 + msr cpacr_el1, x0 // Enable FP/ASIMD + mov x0, #1 << 12 // Reset mdscr_el1 and disable + msr mdscr_el1, x0 // access to the DCC from EL0 + isb // Unmask debug exceptions now, + enable_dbg // since this is per-cpu + reset_pmuserenr_el0 x0 // Disable PMU access from EL0 + /* + * Memory region attributes for LPAE: + * + * n = AttrIndx[2:0] + * n MAIR + * DEVICE_nGnRnE 000 00000000 + * DEVICE_nGnRE 001 00000100 + * DEVICE_GRE 010 00001100 + * NORMAL_NC 011 01000100 + * NORMAL 100 11111111 + * NORMAL_WT 101 10111011 + */ + ldr x5, =MAIR(0x00, MT_DEVICE_nGnRnE) | \ + MAIR(0x04, MT_DEVICE_nGnRE) | \ + MAIR(0x0c, MT_DEVICE_GRE) | \ + MAIR(0x44, MT_NORMAL_NC) | \ + MAIR(0xff, MT_NORMAL) | \ + MAIR(0xbb, MT_NORMAL_WT) + msr mair_el1, x5 + /* + * Prepare SCTLR + */ + mov_q x0, SCTLR_EL1_SET + /* + * Set/prepare TCR and TTBR. We use 512GB (39-bit) address range for + * both user and kernel. + */ + ldr x10, =TCR_TxSZ(VA_BITS) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \ + TCR_TG_FLAGS | TCR_KASLR_FLAGS | TCR_ASID16 | \ + TCR_TBI0 | TCR_A1 + tcr_set_idmap_t0sz x10, x9 + + /* + * Set the IPS bits in TCR_EL1. + */ + tcr_compute_pa_size x10, #TCR_IPS_SHIFT, x5, x6 +#ifdef CONFIG_ARM64_HW_AFDBM + /* + * Enable hardware update of the Access Flags bit. + * Hardware dirty bit management is enabled later, + * via capabilities. + */ + mrs x9, ID_AA64MMFR1_EL1 + and x9, x9, #0xf + cbz x9, 1f + orr x10, x10, #TCR_HA // hardware Access flag update +1: +#endif /* CONFIG_ARM64_HW_AFDBM */ + msr tcr_el1, x10 + ret // return to head.S +ENDPROC(__cpu_setup) |