Introduce a new Kconfig, ARM64_BOOT_TIME_PAGE_SIZE, which can be selected instead of a page size. When selected, the resulting kernel's page size can be configured at boot via the command line. For now, boot-time page size kernels are limited to 48-bit VA, since more work is required to support LPA2. Additionally MMAP_RND_BITS and SECTION_SIZE_BITS are configured for the worst case (64K pages). Future work could be implemented to be able to configure these at boot time for optimial page size-specific values. Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx> --- ***NOTE*** Any confused maintainers may want to read the cover note here for context: https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@xxxxxxx/ arch/arm64/Kconfig | 26 ++++++++++--- arch/arm64/include/asm/kvm_hyp.h | 11 ++++++ arch/arm64/include/asm/pgtable-geometry.h | 22 ++++++++++- arch/arm64/include/asm/pgtable-hwdef.h | 6 +-- arch/arm64/include/asm/pgtable.h | 10 ++++- arch/arm64/include/asm/sparsemem.h | 4 ++ arch/arm64/kernel/image-vars.h | 11 ++++++ arch/arm64/kernel/image.h | 4 ++ arch/arm64/kernel/pi/map_kernel.c | 45 ++++++++++++++++++++++ arch/arm64/kvm/arm.c | 10 +++++ arch/arm64/kvm/hyp/nvhe/Makefile | 1 + arch/arm64/kvm/hyp/nvhe/pgtable-geometry.c | 16 ++++++++ arch/arm64/mm/Makefile | 1 + arch/arm64/mm/pgd.c | 10 +++-- arch/arm64/mm/pgtable-geometry.c | 24 ++++++++++++ drivers/firmware/efi/libstub/arm64.c | 3 +- 16 files changed, 187 insertions(+), 17 deletions(-) create mode 100644 arch/arm64/kvm/hyp/nvhe/pgtable-geometry.c create mode 100644 arch/arm64/mm/pgtable-geometry.c diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index a2f8ff354ca67..573d308741169 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -121,6 +121,7 @@ config ARM64 select BUILDTIME_TABLE_SORT select CLONE_BACKWARDS select COMMON_CLK + select CONSTRUCTORS if ARM64_BOOT_TIME_PAGE_SIZE select CPU_PM if (SUSPEND || CPU_IDLE) select CPUMASK_OFFSTACK if NR_CPUS > 256 select CRC32 @@ -284,18 +285,20 @@ config MMU config ARM64_CONT_PTE_SHIFT int + depends on !ARM64_BOOT_TIME_PAGE_SIZE default 5 if PAGE_SIZE_64KB default 7 if PAGE_SIZE_16KB default 4 config ARM64_CONT_PMD_SHIFT int + depends on !ARM64_BOOT_TIME_PAGE_SIZE default 5 if PAGE_SIZE_64KB default 5 if PAGE_SIZE_16KB default 4 config ARCH_MMAP_RND_BITS_MIN - default 14 if PAGE_SIZE_64KB + default 14 if ARM64_64K_PAGES || ARM64_BOOT_TIME_PAGE_SIZE default 16 if PAGE_SIZE_16KB default 18 @@ -306,15 +309,15 @@ config ARCH_MMAP_RND_BITS_MAX default 24 if ARM64_VA_BITS=39 default 27 if ARM64_VA_BITS=42 default 30 if ARM64_VA_BITS=47 - default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES + default 29 if ARM64_VA_BITS=48 && (ARM64_64K_PAGES || ARM64_BOOT_TIME_PAGE_SIZE) default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES default 33 if ARM64_VA_BITS=48 - default 14 if ARM64_64K_PAGES + default 14 if ARM64_64K_PAGES || ARM64_BOOT_TIME_PAGE_SIZE default 16 if ARM64_16K_PAGES default 18 config ARCH_MMAP_RND_COMPAT_BITS_MIN - default 7 if ARM64_64K_PAGES + default 7 if ARM64_64K_PAGES || ARM64_BOOT_TIME_PAGE_SIZE default 9 if ARM64_16K_PAGES default 11 @@ -362,6 +365,7 @@ config FIX_EARLYCON_MEM config PGTABLE_LEVELS int + default 4 if ARM64_BOOT_TIME_PAGE_SIZE # Advertise max supported levels default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) @@ -1316,6 +1320,14 @@ config ARM64_64K_PAGES look-up. AArch32 emulation requires applications compiled with 64K aligned segments. +config ARM64_BOOT_TIME_PAGE_SIZE + bool "Boot-time selection" + select HAVE_PAGE_SIZE_64KB # Advertise largest page size to core + help + Select desired page size (4KB, 16KB or 64KB) at boot-time via the + kernel command line option "arm64.pagesize=4k", "arm64.pagesize=16k" + or "arm64.pagesize=64k". + endchoice choice @@ -1348,6 +1360,7 @@ config ARM64_VA_BITS_48 config ARM64_VA_BITS_52 bool "52-bit" depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN + depends on !ARM64_BOOT_TIME_PAGE_SIZE help Enable 52-bit virtual addressing for userspace when explicitly requested via a hint to mmap(). The kernel will also use 52-bit @@ -1588,9 +1601,10 @@ config XEN # 4K | 27 | 12 | 15 | 10 | # 16K | 27 | 14 | 13 | 11 | # 64K | 29 | 16 | 13 | 13 | +# BOOT| 29 | 16 (max) | 13 | 13 | config ARCH_FORCE_MAX_ORDER int - default "13" if ARM64_64K_PAGES + default "13" if ARM64_64K_PAGES || ARM64_BOOT_TIME_PAGE_SIZE default "11" if ARM64_16K_PAGES default "10" help @@ -1663,7 +1677,7 @@ config ARM64_TAGGED_ADDR_ABI menuconfig COMPAT bool "Kernel support for 32-bit EL0" - depends on ARM64_4K_PAGES || EXPERT + depends on ARM64_4K_PAGES || ARM64_BOOT_TIME_PAGE_SIZE || EXPERT select HAVE_UID16 select OLD_SIGSUSPEND3 select COMPAT_OLD_SIGACTION diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index c838309e4ec47..9397a14642afa 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -145,4 +145,15 @@ extern unsigned long kvm_nvhe_sym(__icache_flags); extern unsigned int kvm_nvhe_sym(kvm_arm_vmid_bits); extern unsigned int kvm_nvhe_sym(kvm_host_sve_max_vl); +#ifdef CONFIG_ARM64_BOOT_TIME_PAGE_SIZE +extern int kvm_nvhe_sym(ptg_page_shift); +extern int kvm_nvhe_sym(ptg_pmd_shift); +extern int kvm_nvhe_sym(ptg_pud_shift); +extern int kvm_nvhe_sym(ptg_p4d_shift); +extern int kvm_nvhe_sym(ptg_pgdir_shift); +extern int kvm_nvhe_sym(ptg_cont_pte_shift); +extern int kvm_nvhe_sym(ptg_cont_pmd_shift); +extern int kvm_nvhe_sym(ptg_pgtable_levels); +#endif /* CONFIG_ARM64_BOOT_TIME_PAGE_SIZE */ + #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/include/asm/pgtable-geometry.h b/arch/arm64/include/asm/pgtable-geometry.h index 62fe125909c08..18a8c8d499ecc 100644 --- a/arch/arm64/include/asm/pgtable-geometry.h +++ b/arch/arm64/include/asm/pgtable-geometry.h @@ -6,16 +6,33 @@ #define ARM64_PAGE_SHIFT_16K 14 #define ARM64_PAGE_SHIFT_64K 16 +#ifdef CONFIG_ARM64_BOOT_TIME_PAGE_SIZE +#define PAGE_SHIFT_MIN ARM64_PAGE_SHIFT_4K +#define PAGE_SHIFT_MAX ARM64_PAGE_SHIFT_64K +#else /* CONFIG_ARM64_BOOT_TIME_PAGE_SIZE */ #define PAGE_SHIFT_MIN CONFIG_PAGE_SHIFT +#define PAGE_SHIFT_MAX CONFIG_PAGE_SHIFT +#endif /* CONFIG_ARM64_BOOT_TIME_PAGE_SIZE */ + #define PAGE_SIZE_MIN (_AC(1, UL) << PAGE_SHIFT_MIN) #define PAGE_MASK_MIN (~(PAGE_SIZE_MIN-1)) - -#define PAGE_SHIFT_MAX CONFIG_PAGE_SHIFT #define PAGE_SIZE_MAX (_AC(1, UL) << PAGE_SHIFT_MAX) #define PAGE_MASK_MAX (~(PAGE_SIZE_MAX-1)) #include <asm-generic/pgtable-geometry.h> +#ifdef CONFIG_ARM64_BOOT_TIME_PAGE_SIZE +#ifndef __ASSEMBLY__ +extern int ptg_page_shift; +extern int ptg_pmd_shift; +extern int ptg_pud_shift; +extern int ptg_p4d_shift; +extern int ptg_pgdir_shift; +extern int ptg_cont_pte_shift; +extern int ptg_cont_pmd_shift; +extern int ptg_pgtable_levels; +#endif /* __ASSEMBLY__ */ +#else /* CONFIG_ARM64_BOOT_TIME_PAGE_SIZE */ #define ptg_page_shift CONFIG_PAGE_SHIFT #define ptg_pmd_shift ARM64_HW_PGTABLE_LEVEL_SHIFT(2) #define ptg_pud_shift ARM64_HW_PGTABLE_LEVEL_SHIFT(1) @@ -24,5 +41,6 @@ #define ptg_cont_pte_shift (CONFIG_ARM64_CONT_PTE_SHIFT + PAGE_SHIFT) #define ptg_cont_pmd_shift (CONFIG_ARM64_CONT_PMD_SHIFT + PMD_SHIFT) #define ptg_pgtable_levels CONFIG_PGTABLE_LEVELS +#endif /* CONFIG_ARM64_BOOT_TIME_PAGE_SIZE */ #endif /* ASM_PGTABLE_GEOMETRY_H */ diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index ca8bcbc1fe220..da5404617acbf 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -52,7 +52,7 @@ #define PMD_SHIFT ptg_pmd_shift #define PMD_SIZE (_AC(1, UL) << PMD_SHIFT) #define PMD_MASK (~(PMD_SIZE-1)) -#define PTRS_PER_PMD (1 << (PAGE_SHIFT - 3)) +#define PTRS_PER_PMD (ptg_pgtable_levels > 2 ? (1 << (PAGE_SHIFT - 3)) : 1) #define MAX_PTRS_PER_PMD (1 << (PAGE_SHIFT_MAX - 3)) #endif @@ -63,7 +63,7 @@ #define PUD_SHIFT ptg_pud_shift #define PUD_SIZE (_AC(1, UL) << PUD_SHIFT) #define PUD_MASK (~(PUD_SIZE-1)) -#define PTRS_PER_PUD (1 << (PAGE_SHIFT - 3)) +#define PTRS_PER_PUD (ptg_pgtable_levels > 3 ? (1 << (PAGE_SHIFT - 3)) : 1) #define MAX_PTRS_PER_PUD (1 << (PAGE_SHIFT_MAX - 3)) #endif @@ -71,7 +71,7 @@ #define P4D_SHIFT ptg_p4d_shift #define P4D_SIZE (_AC(1, UL) << P4D_SHIFT) #define P4D_MASK (~(P4D_SIZE-1)) -#define PTRS_PER_P4D (1 << (PAGE_SHIFT - 3)) +#define PTRS_PER_P4D (ptg_pgtable_levels > 4 ? (1 << (PAGE_SHIFT - 3)) : 1) #define MAX_PTRS_PER_P4D (1 << (PAGE_SHIFT_MAX - 3)) #endif diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 8ead41da715b0..ad9f75f5cc29a 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -755,7 +755,7 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd) static __always_inline bool pgtable_l3_enabled(void) { - return true; + return ptg_pgtable_levels > 2; } static inline bool mm_pmd_folded(const struct mm_struct *mm) @@ -888,6 +888,8 @@ static inline bool pgtable_l3_enabled(void) { return false; } static __always_inline bool pgtable_l4_enabled(void) { + if (IS_ENABLED(CONFIG_ARM64_BOOT_TIME_PAGE_SIZE)) + return ptg_pgtable_levels > 3; if (CONFIG_PGTABLE_LEVELS > 4 || !IS_ENABLED(CONFIG_ARM64_LPA2)) return true; if (!alternative_has_cap_likely(ARM64_ALWAYS_BOOT)) @@ -935,6 +937,8 @@ static inline phys_addr_t p4d_page_paddr(p4d_t p4d) static inline pud_t *p4d_to_folded_pud(p4d_t *p4dp, unsigned long addr) { + if (IS_ENABLED(CONFIG_ARM64_BOOT_TIME_PAGE_SIZE)) + return (pud_t *)p4dp; return (pud_t *)PTR_ALIGN_DOWN(p4dp, PAGE_SIZE) + pud_index(addr); } @@ -1014,6 +1018,8 @@ static inline bool pgtable_l4_enabled(void) { return false; } static __always_inline bool pgtable_l5_enabled(void) { + if (IS_ENABLED(CONFIG_ARM64_BOOT_TIME_PAGE_SIZE)) + return ptg_pgtable_levels > 4; if (!alternative_has_cap_likely(ARM64_ALWAYS_BOOT)) return vabits_actual == VA_BITS; return alternative_has_cap_unlikely(ARM64_HAS_VA52); @@ -1059,6 +1065,8 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd) static inline p4d_t *pgd_to_folded_p4d(pgd_t *pgdp, unsigned long addr) { + if (IS_ENABLED(CONFIG_ARM64_BOOT_TIME_PAGE_SIZE)) + return (p4d_t *)pgdp; return (p4d_t *)PTR_ALIGN_DOWN(pgdp, PAGE_SIZE) + p4d_index(addr); } diff --git a/arch/arm64/include/asm/sparsemem.h b/arch/arm64/include/asm/sparsemem.h index a05fdd54014f7..2daf1263ba638 100644 --- a/arch/arm64/include/asm/sparsemem.h +++ b/arch/arm64/include/asm/sparsemem.h @@ -17,6 +17,10 @@ * entries could not be created for vmemmap mappings. * 16K follows 4K for simplicity. */ +#ifdef CONFIG_ARM64_BOOT_TIME_PAGE_SIZE +#define SECTION_SIZE_BITS 29 +#else #define SECTION_SIZE_BITS (PAGE_SIZE == SZ_64K ? 29 : 27) +#endif #endif diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h index a168f3337446f..9968320f83bc4 100644 --- a/arch/arm64/kernel/image-vars.h +++ b/arch/arm64/kernel/image-vars.h @@ -36,6 +36,17 @@ PROVIDE(__pi___memcpy = __pi_memcpy); PROVIDE(__pi___memmove = __pi_memmove); PROVIDE(__pi___memset = __pi_memset); +#ifdef CONFIG_ARM64_BOOT_TIME_PAGE_SIZE +PROVIDE(__pi_ptg_page_shift = ptg_page_shift); +PROVIDE(__pi_ptg_pmd_shift = ptg_pmd_shift); +PROVIDE(__pi_ptg_pud_shift = ptg_pud_shift); +PROVIDE(__pi_ptg_p4d_shift = ptg_p4d_shift); +PROVIDE(__pi_ptg_pgdir_shift = ptg_pgdir_shift); +PROVIDE(__pi_ptg_cont_pte_shift = ptg_cont_pte_shift); +PROVIDE(__pi_ptg_cont_pmd_shift = ptg_cont_pmd_shift); +PROVIDE(__pi_ptg_pgtable_levels = ptg_pgtable_levels); +#endif /* CONFIG_ARM64_BOOT_TIME_PAGE_SIZE */ + PROVIDE(__pi_id_aa64isar1_override = id_aa64isar1_override); PROVIDE(__pi_id_aa64isar2_override = id_aa64isar2_override); PROVIDE(__pi_id_aa64mmfr0_override = id_aa64mmfr0_override); diff --git a/arch/arm64/kernel/image.h b/arch/arm64/kernel/image.h index 7bc3ba8979019..01502fc3b891b 100644 --- a/arch/arm64/kernel/image.h +++ b/arch/arm64/kernel/image.h @@ -47,7 +47,11 @@ #define __HEAD_FLAG_BE ARM64_IMAGE_FLAG_LE #endif +#ifdef CONFIG_ARM64_BOOT_TIME_PAGE_SIZE +#define __HEAD_FLAG_PAGE_SIZE 0 +#else #define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2) +#endif #define __HEAD_FLAG_PHYS_BASE 1 diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c index deb8cd50b0b0c..22b3c70e04f9c 100644 --- a/arch/arm64/kernel/pi/map_kernel.c +++ b/arch/arm64/kernel/pi/map_kernel.c @@ -221,6 +221,49 @@ static void __init map_fdt(u64 fdt, int page_shift) dsb(ishst); } +#ifdef CONFIG_ARM64_BOOT_TIME_PAGE_SIZE +static void __init ptg_init(int page_shift) +{ + ptg_pgtable_levels = + __ARM64_HW_PGTABLE_LEVELS(page_shift, CONFIG_ARM64_VA_BITS); + + ptg_pgdir_shift = __ARM64_HW_PGTABLE_LEVEL_SHIFT(page_shift, + 4 - ptg_pgtable_levels); + + ptg_p4d_shift = ptg_pgtable_levels >= 5 ? + __ARM64_HW_PGTABLE_LEVEL_SHIFT(page_shift, 0) : + ptg_pgdir_shift; + + ptg_pud_shift = ptg_pgtable_levels >= 4 ? + __ARM64_HW_PGTABLE_LEVEL_SHIFT(page_shift, 1) : + ptg_pgdir_shift; + + ptg_pmd_shift = ptg_pgtable_levels >= 3 ? + __ARM64_HW_PGTABLE_LEVEL_SHIFT(page_shift, 2) : + ptg_pgdir_shift; + + ptg_page_shift = page_shift; + + switch (page_shift) { + case ARM64_PAGE_SHIFT_64K: + ptg_cont_pte_shift = ptg_page_shift + 5; + ptg_cont_pmd_shift = ptg_pmd_shift + 5; + break; + case ARM64_PAGE_SHIFT_16K: + ptg_cont_pte_shift = ptg_page_shift + 7; + ptg_cont_pmd_shift = ptg_pmd_shift + 5; + break; + default: /* ARM64_PAGE_SHIFT_4K */ + ptg_cont_pte_shift = ptg_page_shift + 4; + ptg_cont_pmd_shift = ptg_pmd_shift + 4; + } +} +#else /* CONFIG_ARM64_BOOT_TIME_PAGE_SIZE */ +static inline void ptg_init(int page_shift) +{ +} +#endif /* CONFIG_ARM64_BOOT_TIME_PAGE_SIZE */ + asmlinkage void __init early_map_kernel(u64 boot_status, void *fdt) { static char const chosen_str[] __initconst = "/chosen"; @@ -247,6 +290,8 @@ asmlinkage void __init early_map_kernel(u64 boot_status, void *fdt) if (!page_shift) page_shift = early_page_shift; + ptg_init(page_shift); + if (va_bits > 48) { u64 page_size = early_page_size(page_shift); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 9bef7638342ef..c835a50b8b768 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2424,6 +2424,16 @@ static void kvm_hyp_init_symbols(void) kvm_nvhe_sym(id_aa64smfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64SMFR0_EL1); kvm_nvhe_sym(__icache_flags) = __icache_flags; kvm_nvhe_sym(kvm_arm_vmid_bits) = kvm_arm_vmid_bits; +#ifdef CONFIG_ARM64_BOOT_TIME_PAGE_SIZE + kvm_nvhe_sym(ptg_page_shift) = ptg_page_shift; + kvm_nvhe_sym(ptg_pmd_shift) = ptg_pmd_shift; + kvm_nvhe_sym(ptg_pud_shift) = ptg_pud_shift; + kvm_nvhe_sym(ptg_p4d_shift) = ptg_p4d_shift; + kvm_nvhe_sym(ptg_pgdir_shift) = ptg_pgdir_shift; + kvm_nvhe_sym(ptg_cont_pte_shift) = ptg_cont_pte_shift; + kvm_nvhe_sym(ptg_cont_pmd_shift) = ptg_cont_pmd_shift; + kvm_nvhe_sym(ptg_pgtable_levels) = ptg_pgtable_levels; +#endif /* CONFIG_ARM64_BOOT_TIME_PAGE_SIZE */ } static int __init kvm_hyp_init_protection(u32 hyp_va_bits) diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile index b43426a493df5..a8fcbb84c7996 100644 --- a/arch/arm64/kvm/hyp/nvhe/Makefile +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -27,6 +27,7 @@ hyp-obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o stacktrace.o ffa.o hyp-obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \ ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o +hyp-obj-$(CONFIG_ARM64_BOOT_TIME_PAGE_SIZE) += pgtable-geometry.o hyp-obj-$(CONFIG_LIST_HARDENED) += list_debug.o hyp-obj-y += $(lib-objs) diff --git a/arch/arm64/kvm/hyp/nvhe/pgtable-geometry.c b/arch/arm64/kvm/hyp/nvhe/pgtable-geometry.c new file mode 100644 index 0000000000000..17f807450a31a --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/pgtable-geometry.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024 ARM Ltd. + */ + +#include <linux/cache.h> +#include <asm/pgtable-geometry.h> + +int ptg_page_shift __ro_after_init; +int ptg_pmd_shift __ro_after_init; +int ptg_pud_shift __ro_after_init; +int ptg_p4d_shift __ro_after_init; +int ptg_pgdir_shift __ro_after_init; +int ptg_cont_pte_shift __ro_after_init; +int ptg_cont_pmd_shift __ro_after_init; +int ptg_pgtable_levels __ro_after_init; diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile index 60454256945b8..2ba30d06b35fe 100644 --- a/arch/arm64/mm/Makefile +++ b/arch/arm64/mm/Makefile @@ -3,6 +3,7 @@ obj-y := dma-mapping.o extable.o fault.o init.o \ cache.o copypage.o flush.o \ ioremap.o mmap.o pgd.o mmu.o \ context.o proc.o pageattr.o fixmap.o +obj-$(CONFIG_ARM64_BOOT_TIME_PAGE_SIZE) += pgtable-geometry.o obj-$(CONFIG_ARM64_CONTPTE) += contpte.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o obj-$(CONFIG_PTDUMP_CORE) += ptdump.o diff --git a/arch/arm64/mm/pgd.c b/arch/arm64/mm/pgd.c index 4b106510358b1..c052d0dcb0c69 100644 --- a/arch/arm64/mm/pgd.c +++ b/arch/arm64/mm/pgd.c @@ -21,10 +21,12 @@ static bool pgdir_is_page_size(void) { if (PGD_SIZE == PAGE_SIZE) return true; - if (CONFIG_PGTABLE_LEVELS == 4) - return !pgtable_l4_enabled(); - if (CONFIG_PGTABLE_LEVELS == 5) - return !pgtable_l5_enabled(); + if (!IS_ENABLED(CONFIG_ARM64_BOOT_TIME_PAGE_SIZE)) { + if (CONFIG_PGTABLE_LEVELS == 4) + return !pgtable_l4_enabled(); + if (CONFIG_PGTABLE_LEVELS == 5) + return !pgtable_l5_enabled(); + } return false; } diff --git a/arch/arm64/mm/pgtable-geometry.c b/arch/arm64/mm/pgtable-geometry.c new file mode 100644 index 0000000000000..ba50637f1e9d0 --- /dev/null +++ b/arch/arm64/mm/pgtable-geometry.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024 ARM Ltd. + */ + +#include <linux/cache.h> +#include <asm/pgtable-geometry.h> + +/* + * TODO: These should be __ro_after_init, but we need to write to them from the + * pi code where they are mapped in the early page table as read-only. + * __ro_after_init doesn't become writable until later when the swapper pgtable + * is fully set up. We should update the early page table to map __ro_after_init + * as read-write. + */ + +int ptg_page_shift __read_mostly; +int ptg_pmd_shift __read_mostly; +int ptg_pud_shift __read_mostly; +int ptg_p4d_shift __read_mostly; +int ptg_pgdir_shift __read_mostly; +int ptg_cont_pte_shift __read_mostly; +int ptg_cont_pmd_shift __read_mostly; +int ptg_pgtable_levels __read_mostly; diff --git a/drivers/firmware/efi/libstub/arm64.c b/drivers/firmware/efi/libstub/arm64.c index e57cd3de0a00f..8db9dba7d5423 100644 --- a/drivers/firmware/efi/libstub/arm64.c +++ b/drivers/firmware/efi/libstub/arm64.c @@ -68,7 +68,8 @@ efi_status_t check_platform_features(void) efi_novamap = true; /* UEFI mandates support for 4 KB granularity, no need to check */ - if (IS_ENABLED(CONFIG_ARM64_4K_PAGES)) + if (IS_ENABLED(CONFIG_ARM64_4K_PAGES) || + IS_ENABLED(CONFIG_ARM64_BOOT_TIME_PAGE_SIZE)) return EFI_SUCCESS; tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_EL1_TGRAN_SHIFT) & 0xf; -- 2.43.0
