On 15/10/2024 18:52, Michael Kelley wrote: > From: Ryan Roberts <ryan.roberts@xxxxxxx> Sent: Monday, October 14, 2024 3:59 AM >> >> 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; > > I found that ptg_page_shift and ptg_pmd_shift need > EXPORT_SYMBOL_GPL for cases where code compiled > as a module is using PAGE_SIZE/PAGE_SHIFT or > PMD_SIZE/PMD_SHIFT. Some of the others below > might also need EXPORT_SYMBOL_GPL. Ahh good spot - thanks! I'll fix this in the next version. I wonder if these should really be EXPORT_SYMBOL() and not limited to GPL? I guess having access to PAGE_SIZE is a pretty fundamental thing? Anybody know the policy here? Thanks, Ryan > > Michael > >> +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 >> >
