| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* |
| * 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> |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/linkage.h> |
| #include <linux/pgtable.h> |
| #include <asm/assembler.h> |
| #include <asm/asm-offsets.h> |
| #include <asm/asm_pointer_auth.h> |
| #include <asm/hwcap.h> |
| #include <asm/pgtable-hwdef.h> |
| #include <asm/cpufeature.h> |
| #include <asm/alternative.h> |
| #include <asm/smp.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 |
| |
| #ifdef CONFIG_KASAN_SW_TAGS |
| #define TCR_KASAN_FLAGS TCR_TBI1 |
| #else |
| #define TCR_KASAN_FLAGS 0 |
| #endif |
| |
| /* Default MAIR_EL1 */ |
| #define MAIR_EL1_SET \ |
| (MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRnE, MT_DEVICE_nGnRnE) | \ |
| MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRE, MT_DEVICE_nGnRE) | \ |
| MAIR_ATTRIDX(MAIR_ATTR_DEVICE_GRE, MT_DEVICE_GRE) | \ |
| MAIR_ATTRIDX(MAIR_ATTR_NORMAL_NC, MT_NORMAL_NC) | \ |
| MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL) | \ |
| MAIR_ATTRIDX(MAIR_ATTR_NORMAL_WT, MT_NORMAL_WT)) |
| |
| #ifdef CONFIG_CPU_PM |
| /** |
| * cpu_do_suspend - save CPU registers context |
| * |
| * x0: virtual address of context pointer |
| * |
| * This must be kept in sync with struct cpu_suspend_ctx in <asm/suspend.h>. |
| */ |
| SYM_FUNC_START(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] |
| /* |
| * Save x18 as it may be used as a platform register, e.g. by shadow |
| * call stack. |
| */ |
| str x18, [x0, #96] |
| ret |
| SYM_FUNC_END(cpu_do_suspend) |
| |
| /** |
| * cpu_do_resume - restore CPU register context |
| * |
| * x0: Address of context pointer |
| */ |
| .pushsection ".idmap.text", "awx" |
| SYM_FUNC_START(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] |
| /* |
| * Restore x18, as it may be used as a platform register, and clear |
| * the buffer to minimize the risk of exposure when used for shadow |
| * call stack. |
| */ |
| ldr x18, [x0, #96] |
| str xzr, [x0, #96] |
| 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 |
| reset_amuserenr_el0 x0 // Disable AMU access from EL0 |
| |
| alternative_if ARM64_HAS_RAS_EXTN |
| msr_s SYS_DISR_EL1, xzr |
| alternative_else_nop_endif |
| |
| ptrauth_keys_install_kernel_nosync x14, x1, x2, x3 |
| isb |
| ret |
| SYM_FUNC_END(cpu_do_resume) |
| .popsection |
| #endif |
| |
| .pushsection ".idmap.text", "awx" |
| |
| .macro __idmap_cpu_set_reserved_ttbr1, tmp1, tmp2 |
| adrp \tmp1, empty_zero_page |
| phys_to_ttbr \tmp2, \tmp1 |
| offset_ttbr1 \tmp2, \tmp1 |
| msr ttbr1_el1, \tmp2 |
| isb |
| tlbi vmalle1 |
| dsb nsh |
| isb |
| .endm |
| |
| /* |
| * void idmap_cpu_replace_ttbr1(phys_addr_t ttbr1) |
| * |
| * 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. |
| */ |
| SYM_FUNC_START(idmap_cpu_replace_ttbr1) |
| save_and_disable_daif flags=x2 |
| |
| __idmap_cpu_set_reserved_ttbr1 x1, x3 |
| |
| offset_ttbr1 x0, x3 |
| msr ttbr1_el1, x0 |
| isb |
| |
| restore_daif x2 |
| |
| ret |
| SYM_FUNC_END(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 |
| SYM_FUNC_START(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 |
| restore_ttbr1 swapper_ttb |
| 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 w17, [flag_ptr] |
| eor w17, w17, num_cpus |
| cbnz w17, 1b |
| |
| /* We need to walk swapper, so turn off the MMU. */ |
| pre_disable_mmu_workaround |
| mrs x17, sctlr_el1 |
| bic x17, x17, #SCTLR_ELx_M |
| msr sctlr_el1, x17 |
| 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 x17, sctlr_el1 |
| orr x17, x17, #SCTLR_ELx_M |
| msr sctlr_el1, x17 |
| 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 |
| |
| .unreq cpu |
| .unreq num_cpus |
| .unreq swapper_pa |
| .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 |
| |
| /* Secondary CPUs end up here */ |
| __idmap_kpti_secondary: |
| /* Uninstall swapper before surgery begins */ |
| __idmap_cpu_set_reserved_ttbr1 x16, x17 |
| |
| /* Increment the flag to let the boot CPU we're ready */ |
| 1: ldxr w16, [flag_ptr] |
| add w16, w16, #1 |
| stxr w17, w16, [flag_ptr] |
| cbnz w17, 1b |
| |
| /* Wait for the boot CPU to finish messing around with swapper */ |
| sevl |
| 1: wfe |
| ldxr w16, [flag_ptr] |
| cbnz w16, 1b |
| |
| /* All done, act like nothing happened */ |
| offset_ttbr1 swapper_ttb, x16 |
| msr ttbr1_el1, swapper_ttb |
| isb |
| ret |
| |
| .unreq swapper_ttb |
| .unreq flag_ptr |
| SYM_FUNC_END(idmap_kpti_install_ng_mappings) |
| .popsection |
| #endif |
| |
| /* |
| * __cpu_setup |
| * |
| * Initialise the processor for turning the MMU on. |
| * |
| * Output: |
| * Return in x0 the value of the SCTLR_EL1 register. |
| */ |
| .pushsection ".idmap.text", "awx" |
| SYM_FUNC_START(__cpu_setup) |
| tlbi vmalle1 // Invalidate local TLB |
| dsb nsh |
| |
| mov x1, #3 << 20 |
| msr cpacr_el1, x1 // Enable FP/ASIMD |
| mov x1, #1 << 12 // Reset mdscr_el1 and disable |
| msr mdscr_el1, x1 // access to the DCC from EL0 |
| isb // Unmask debug exceptions now, |
| enable_dbg // since this is per-cpu |
| reset_pmuserenr_el0 x1 // Disable PMU access from EL0 |
| reset_amuserenr_el0 x1 // Disable AMU access from EL0 |
| |
| /* |
| * Memory region attributes |
| */ |
| mov_q x5, MAIR_EL1_SET |
| msr mair_el1, x5 |
| /* |
| * Set/prepare TCR and TTBR. We use 512GB (39-bit) address range for |
| * both user and kernel. |
| */ |
| mov_q x10, TCR_TxSZ(VA_BITS) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \ |
| TCR_TG_FLAGS | TCR_KASLR_FLAGS | TCR_ASID16 | \ |
| TCR_TBI0 | TCR_A1 | TCR_KASAN_FLAGS |
| tcr_clear_errata_bits x10, x9, x5 |
| |
| #ifdef CONFIG_ARM64_VA_BITS_52 |
| ldr_l x9, vabits_actual |
| sub x9, xzr, x9 |
| add x9, x9, #64 |
| tcr_set_t1sz x10, x9 |
| #else |
| ldr_l x9, idmap_t0sz |
| #endif |
| tcr_set_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 |
| /* |
| * Prepare SCTLR |
| */ |
| mov_q x0, SCTLR_EL1_SET |
| ret // return to head.S |
| SYM_FUNC_END(__cpu_setup) |
