/* 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 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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_SW_FLAGS TCR_TBI1 | TCR_TBID1 #else #define TCR_KASAN_SW_FLAGS 0 #endif #ifdef CONFIG_KASAN_HW_TAGS #define TCR_MTE_FLAGS TCR_TCMA1 | TCR_TBI1 | TCR_TBID1 #elif defined(CONFIG_ARM64_MTE) /* * The mte_zero_clear_page_tags() implementation uses DC GZVA, which relies on * TBI being enabled at EL1. */ #define TCR_MTE_FLAGS TCR_TBI1 | TCR_TBID1 #else #define TCR_MTE_FLAGS 0 #endif /* * Default MAIR_EL1. MT_NORMAL_TAGGED is initially mapped as Normal memory and * changed during mte_cpu_setup to Normal Tagged if the system supports MTE. */ #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_NORMAL_NC, MT_NORMAL_NC) | \ MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL) | \ MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL_TAGGED)) #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 . */ 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 get_this_cpu_offset x12 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 */ 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 set_this_cpu_offset x13 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) #endif .pushsection ".idmap.text", "a" .macro __idmap_cpu_set_reserved_ttbr1, tmp1, tmp2 adrp \tmp1, reserved_pg_dir 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_TYPED_FUNC_START(idmap_cpu_replace_ttbr1) __idmap_cpu_set_reserved_ttbr1 x1, x3 offset_ttbr1 x0, x3 msr ttbr1_el1, x0 isb ret SYM_FUNC_END(idmap_cpu_replace_ttbr1) SYM_FUNC_ALIAS(__pi_idmap_cpu_replace_ttbr1, idmap_cpu_replace_ttbr1) .popsection #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 #define KPTI_NG_PTE_FLAGS (PTE_ATTRINDX(MT_NORMAL) | PTE_TYPE_PAGE | \ PTE_AF | PTE_SHARED | PTE_UXN | PTE_WRITE) .pushsection ".idmap.text", "a" .macro pte_to_phys, phys, pte and \phys, \pte, #PTE_ADDR_LOW #ifdef CONFIG_ARM64_PA_BITS_52 and \pte, \pte, #PTE_ADDR_HIGH orr \phys, \phys, \pte, lsl #PTE_ADDR_HIGH_SHIFT #endif .endm .macro kpti_mk_tbl_ng, type, num_entries add end_\type\()p, cur_\type\()p, #\num_entries * 8 .Ldo_\type: ldr \type, [cur_\type\()p], #8 // Load the entry and advance tbz \type, #0, .Lnext_\type // Skip invalid and tbnz \type, #11, .Lnext_\type // non-global entries orr \type, \type, #PTE_NG // Same bit for blocks and pages str \type, [cur_\type\()p, #-8] // Update the entry .ifnc \type, pte tbnz \type, #1, .Lderef_\type .endif .Lnext_\type: cmp cur_\type\()p, end_\type\()p b.ne .Ldo_\type .endm /* * Dereference the current table entry and map it into the temporary * fixmap slot associated with the current level. */ .macro kpti_map_pgtbl, type, level str xzr, [temp_pte, #8 * (\level + 2)] // break before make dsb nshst add pte, temp_pte, #PAGE_SIZE * (\level + 2) lsr pte, pte, #12 tlbi vaae1, pte dsb nsh isb phys_to_pte pte, cur_\type\()p add cur_\type\()p, temp_pte, #PAGE_SIZE * (\level + 2) orr pte, pte, pte_flags str pte, [temp_pte, #8 * (\level + 2)] dsb nshst .endm /* * void __kpti_install_ng_mappings(int cpu, int num_secondaries, phys_addr_t temp_pgd, * unsigned long temp_pte_va) * * Called exactly once from stop_machine context by each CPU found during boot. */ .pushsection ".data", "aw", %progbits SYM_DATA(__idmap_kpti_flag, .long 1) .popsection SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) cpu .req w0 temp_pte .req x0 num_cpus .req w1 pte_flags .req x1 temp_pgd_phys .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 cur_pmdp .req x11 end_pmdp .req x12 cur_ptep .req x14 end_ptep .req x15 pte .req x16 valid .req x17 cur_p4dp .req x19 end_p4dp .req x20 mov x5, x3 // preserve temp_pte arg mrs swapper_ttb, ttbr1_el1 adr_l flag_ptr, __idmap_kpti_flag cbnz cpu, __idmap_kpti_secondary #if CONFIG_PGTABLE_LEVELS > 4 stp x29, x30, [sp, #-32]! mov x29, sp stp x19, x20, [sp, #16] #endif /* 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 /* Switch to the temporary page tables on this CPU only */ __idmap_cpu_set_reserved_ttbr1 x8, x9 offset_ttbr1 temp_pgd_phys, x8 msr ttbr1_el1, temp_pgd_phys isb mov temp_pte, x5 mov_q pte_flags, KPTI_NG_PTE_FLAGS /* Everybody is enjoying the idmap, so we can rewrite swapper. */ #ifdef CONFIG_ARM64_LPA2 /* * If LPA2 support is configured, but 52-bit virtual addressing is not * enabled at runtime, we will fall back to one level of paging less, * and so we have to walk swapper_pg_dir as if we dereferenced its * address from a PGD level entry, and terminate the PGD level loop * right after. */ adrp pgd, swapper_pg_dir // walk &swapper_pg_dir at the next level mov cur_pgdp, end_pgdp // must be equal to terminate the PGD loop alternative_if_not ARM64_HAS_VA52 b .Lderef_pgd // skip to the next level alternative_else_nop_endif /* * LPA2 based 52-bit virtual addressing requires 52-bit physical * addressing to be enabled as well. In this case, the shareability * bits are repurposed as physical address bits, and should not be * set in pte_flags. */ bic pte_flags, pte_flags, #PTE_SHARED #endif /* PGD */ adrp cur_pgdp, swapper_pg_dir kpti_map_pgtbl pgd, -1 kpti_mk_tbl_ng pgd, PTRS_PER_PGD /* Ensure all the updated entries are visible to secondary CPUs */ dsb ishst /* We're done: fire up swapper_pg_dir again */ __idmap_cpu_set_reserved_ttbr1 x8, x9 msr ttbr1_el1, swapper_ttb isb /* Set the flag to zero to indicate that we're all done */ str wzr, [flag_ptr] #if CONFIG_PGTABLE_LEVELS > 4 ldp x19, x20, [sp, #16] ldp x29, x30, [sp], #32 #endif ret .Lderef_pgd: /* P4D */ .if CONFIG_PGTABLE_LEVELS > 4 p4d .req x30 pte_to_phys cur_p4dp, pgd kpti_map_pgtbl p4d, 0 kpti_mk_tbl_ng p4d, PTRS_PER_P4D b .Lnext_pgd .else /* CONFIG_PGTABLE_LEVELS <= 4 */ p4d .req pgd .set .Lnext_p4d, .Lnext_pgd .endif .Lderef_p4d: /* PUD */ .if CONFIG_PGTABLE_LEVELS > 3 pud .req x10 pte_to_phys cur_pudp, p4d kpti_map_pgtbl pud, 1 kpti_mk_tbl_ng pud, PTRS_PER_PUD b .Lnext_p4d .else /* CONFIG_PGTABLE_LEVELS <= 3 */ pud .req pgd .set .Lnext_pud, .Lnext_pgd .endif .Lderef_pud: /* PMD */ .if CONFIG_PGTABLE_LEVELS > 2 pmd .req x13 pte_to_phys cur_pmdp, pud kpti_map_pgtbl pmd, 2 kpti_mk_tbl_ng pmd, PTRS_PER_PMD b .Lnext_pud .else /* CONFIG_PGTABLE_LEVELS <= 2 */ pmd .req pgd .set .Lnext_pmd, .Lnext_pgd .endif .Lderef_pmd: /* PTE */ pte_to_phys cur_ptep, pmd kpti_map_pgtbl pte, 3 kpti_mk_tbl_ng pte, PTRS_PER_PTE b .Lnext_pmd .unreq cpu .unreq temp_pte .unreq num_cpus .unreq pte_flags .unreq temp_pgd_phys .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 .unreq valid .unreq cur_p4dp .unreq end_p4dp .unreq p4d /* 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 */ 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", "a" SYM_FUNC_START(__cpu_setup) tlbi vmalle1 // Invalidate local TLB dsb nsh msr cpacr_el1, xzr // Reset cpacr_el1 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 /* * Default values for VMSA control registers. These will be adjusted * below depending on detected CPU features. */ mair .req x17 tcr .req x16 mov_q mair, MAIR_EL1_SET mov_q tcr, TCR_T0SZ(IDMAP_VA_BITS) | TCR_T1SZ(VA_BITS_MIN) | TCR_CACHE_FLAGS | \ TCR_SMP_FLAGS | TCR_TG_FLAGS | TCR_KASLR_FLAGS | TCR_ASID16 | \ TCR_TBI0 | TCR_A1 | TCR_KASAN_SW_FLAGS | TCR_MTE_FLAGS tcr_clear_errata_bits tcr, x9, x5 #ifdef CONFIG_ARM64_VA_BITS_52 mov x9, #64 - VA_BITS alternative_if ARM64_HAS_VA52 tcr_set_t1sz tcr, x9 #ifdef CONFIG_ARM64_LPA2 orr tcr, tcr, #TCR_DS #endif alternative_else_nop_endif #endif /* * Set the IPS bits in TCR_EL1. */ tcr_compute_pa_size tcr, #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, ID_AA64MMFR1_EL1_HAFDBS_MASK cbz x9, 1f orr tcr, tcr, #TCR_HA // hardware Access flag update 1: #endif /* CONFIG_ARM64_HW_AFDBM */ msr mair_el1, mair msr tcr_el1, tcr mrs_s x1, SYS_ID_AA64MMFR3_EL1 ubfx x1, x1, #ID_AA64MMFR3_EL1_S1PIE_SHIFT, #4 cbz x1, .Lskip_indirection /* * The PROT_* macros describing the various memory types may resolve to * C expressions if they include the PTE_MAYBE_* macros, and so they * can only be used from C code. The PIE_E* constants below are also * defined in terms of those macros, but will mask out those * PTE_MAYBE_* constants, whether they are set or not. So #define them * as 0x0 here so we can evaluate the PIE_E* constants in asm context. */ #define PTE_MAYBE_NG 0 #define PTE_MAYBE_SHARED 0 mov_q x0, PIE_E0 msr REG_PIRE0_EL1, x0 mov_q x0, PIE_E1 msr REG_PIR_EL1, x0 #undef PTE_MAYBE_NG #undef PTE_MAYBE_SHARED mov x0, TCR2_EL1x_PIE msr REG_TCR2_EL1, x0 .Lskip_indirection: /* * Prepare SCTLR */ mov_q x0, INIT_SCTLR_EL1_MMU_ON #ifdef CONFIG_ARM64_WXN ldr_l x1, arm64_sw_feature_override + FTR_OVR_VAL_OFFSET tst x1, #0xf << ARM64_SW_FEATURE_OVERRIDE_NOWXN orr x1, x0, #SCTLR_ELx_WXN csel x0, x0, x1, ne #endif ret // return to head.S .unreq mair .unreq tcr SYM_FUNC_END(__cpu_setup)