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Diffstat (limited to 'arch/arm64/mm/proc.S')
| -rw-r--r-- | arch/arm64/mm/proc.S | 471 |
1 files changed, 471 insertions, 0 deletions
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S new file mode 100644 index 000000000..b9ecbbae1 --- /dev/null +++ b/arch/arm64/mm/proc.S @@ -0,0 +1,471 @@ +/* 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 <linux/cfi_types.h> +#include <asm/assembler.h> +#include <asm/asm-offsets.h> +#include <asm/asm_pointer_auth.h> +#include <asm/hwcap.h> +#include <asm/kernel-pgtable.h> +#include <asm/pgtable-hwdef.h> +#include <asm/cpufeature.h> +#include <asm/alternative.h> +#include <asm/smp.h> +#include <asm/sysreg.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_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 <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 + 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 + */ + .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 + 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) + .popsection +#endif + + .pushsection ".idmap.text", "awx" + +.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) + 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 + +#define KPTI_NG_PTE_FLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS) + + .pushsection ".idmap.text", "awx" + + .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] // Load the entry + 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] // Update the entry + .ifnc \type, pte + tbnz \type, #1, .Lderef_\type + .endif +.Lnext_\type: + add cur_\type\()p, cur_\type\()p, #8 + 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 + 1)] // break before make + dsb nshst + add pte, temp_pte, #PAGE_SIZE * (\level + 1) + 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 + 1) + orr pte, pte, pte_flags + str pte, [temp_pte, #8 * (\level + 1)] + 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 + + mov x5, x3 // preserve temp_pte arg + mrs swapper_ttb, ttbr1_el1 + adr_l 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 + + /* 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 pte_flags, #KPTI_NG_PTE_FLAGS + + /* Everybody is enjoying the idmap, so we can rewrite swapper. */ + /* PGD */ + adrp cur_pgdp, swapper_pg_dir + kpti_map_pgtbl pgd, 0 + 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] + ret + +.Lderef_pgd: + /* PUD */ + .if CONFIG_PGTABLE_LEVELS > 3 + pud .req x10 + pte_to_phys cur_pudp, pgd + kpti_map_pgtbl pud, 1 + kpti_mk_tbl_ng pud, PTRS_PER_PUD + b .Lnext_pgd + .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 + + /* 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. + * + * Input: + * x0 - actual number of VA bits (ignored unless VA_BITS > 48) + * 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 + + /* + * 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_TxSZ(VA_BITS) | 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 + sub x9, xzr, x0 + add x9, x9, #64 + tcr_set_t1sz tcr, x9 +#else + idmap_get_t0sz x9 +#endif + tcr_set_t0sz tcr, x9 + + /* + * 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, #0xf + 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 + /* + * Prepare SCTLR + */ + mov_q x0, INIT_SCTLR_EL1_MMU_ON + ret // return to head.S + + .unreq mair + .unreq tcr +SYM_FUNC_END(__cpu_setup) |