/* 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
/* 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
*/
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
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, MDSCR_EL1_TDCC // Reset mdscr_el1 and disable
msr mdscr_el1, x1 // access to the DCC from EL0
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
tcr2 .req x15
mov_q mair, MAIR_EL1_SET
mov_q tcr, TCR_T0SZ(IDMAP_VA_BITS) | TCR_T1SZ(VA_BITS_MIN) | TCR_CACHE_FLAGS | \
TCR_SHARED | TCR_TG_FLAGS | TCR_KASLR_FLAGS | TCR_ASID16 | \
TCR_TBI0 | TCR_A1 | TCR_KASAN_SW_FLAGS | TCR_MTE_FLAGS
mov tcr2, xzr
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
ubfx x9, x9, ID_AA64MMFR1_EL1_HAFDBS_SHIFT, #4
cbz x9, 1f
orr tcr, tcr, #TCR_HA // hardware Access flag update
#ifdef CONFIG_ARM64_HAFT
cmp x9, ID_AA64MMFR1_EL1_HAFDBS_HAFT
b.lt 1f
orr tcr2, tcr2, TCR2_EL1_HAFT
#endif
/* CONFIG_ARM64_HAFT */
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
mov_q x0, PIE_E0_ASM
msr REG_PIRE0_EL1, x0
mov_q x0, PIE_E1_ASM
msr REG_PIR_EL1, x0
orr tcr2, tcr2, TCR2_EL1_PIE
.Lskip_indirection:
mrs_s x1, SYS_ID_AA64MMFR3_EL1
ubfx x1, x1, #ID_AA64MMFR3_EL1_TCRX_SHIFT, #4
cbz x1, 1f
msr REG_TCR2_EL1, tcr2
1:
/*
* Prepare SCTLR
*/
mov_q x0, INIT_SCTLR_EL1_MMU_ON
ret // return to head.S
.unreq mair
.unreq tcr
.unreq tcr2
SYM_FUNC_END(__cpu_setup)
