From 44eaacf1b8999b15cec89bd9d9cd989da4798d53 Mon Sep 17 00:00:00 2001 From: "Suzuki K. Poulose" Date: Mon, 19 Oct 2015 14:19:37 +0100 Subject: [PATCH] arm64: Add 16K page size support This patch turns on the 16K page support in the kernel. We support 48bit VA (4 level page tables) and 47bit VA (3 level page tables). With 16K we can map 128 entries using contiguous bit hint at level 3 to map 2M using single TLB entry. TODO: 16K supports 32 contiguous entries at level 2 to get us 1G(which is not yet supported by the infrastructure). That should be a separate patch altogether. Cc: Will Deacon Cc: Jeremy Linton Cc: Marc Zyngier Cc: Christoffer Dall Cc: Steve Capper Signed-off-by: Suzuki K. Poulose Reviewed-by: Ard Biesheuvel Tested-by: Ard Biesheuvel Acked-by: Mark Rutland Signed-off-by: Catalin Marinas --- arch/arm64/Kconfig | 42 ++++++++++++++++++++++++---- arch/arm64/include/asm/page.h | 3 ++ arch/arm64/include/asm/sysreg.h | 3 ++ arch/arm64/include/asm/thread_info.h | 2 ++ arch/arm64/kvm/Kconfig | 3 ++ arch/arm64/mm/proc.S | 4 ++- 6 files changed, 51 insertions(+), 6 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 13b51a0c4e7f..854166422c42 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -173,7 +173,8 @@ config PGTABLE_LEVELS default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 - default 4 if ARM64_4K_PAGES && ARM64_VA_BITS_48 + default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 + default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 source "init/Kconfig" @@ -363,6 +364,13 @@ config ARM64_4K_PAGES help This feature enables 4KB pages support. +config ARM64_16K_PAGES + bool "16KB" + help + The system will use 16KB pages support. AArch32 emulation + requires applications compiled with 16K (or a multiple of 16K) + aligned segments. + config ARM64_64K_PAGES bool "64KB" help @@ -376,6 +384,7 @@ endchoice choice prompt "Virtual address space size" default ARM64_VA_BITS_39 if ARM64_4K_PAGES + default ARM64_VA_BITS_47 if ARM64_16K_PAGES default ARM64_VA_BITS_42 if ARM64_64K_PAGES help Allows choosing one of multiple possible virtual address @@ -390,6 +399,10 @@ config ARM64_VA_BITS_42 bool "42-bit" depends on ARM64_64K_PAGES +config ARM64_VA_BITS_47 + bool "47-bit" + depends on ARM64_16K_PAGES + config ARM64_VA_BITS_48 bool "48-bit" @@ -399,6 +412,7 @@ config ARM64_VA_BITS int default 39 if ARM64_VA_BITS_39 default 42 if ARM64_VA_BITS_42 + default 47 if ARM64_VA_BITS_47 default 48 if ARM64_VA_BITS_48 config CPU_BIG_ENDIAN @@ -466,7 +480,7 @@ config ARCH_WANT_GENERAL_HUGETLB def_bool y config ARCH_WANT_HUGE_PMD_SHARE - def_bool y if ARM64_4K_PAGES + def_bool y if ARM64_4K_PAGES || ARM64_16K_PAGES config HAVE_ARCH_TRANSPARENT_HUGEPAGE def_bool y @@ -503,7 +517,25 @@ config XEN config FORCE_MAX_ZONEORDER int default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) + default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE) default "11" + help + The kernel memory allocator divides physically contiguous memory + blocks into "zones", where each zone is a power of two number of + pages. This option selects the largest power of two that the kernel + keeps in the memory allocator. If you need to allocate very large + blocks of physically contiguous memory, then you may need to + increase this value. + + This config option is actually maximum order plus one. For example, + a value of 11 means that the largest free memory block is 2^10 pages. + + We make sure that we can allocate upto a HugePage size for each configuration. + Hence we have : + MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 + + However for 4K, we choose a higher default value, 11 as opposed to 10, giving us + 4M allocations matching the default size used by generic code. menuconfig ARMV8_DEPRECATED bool "Emulate deprecated/obsolete ARMv8 instructions" @@ -689,9 +721,9 @@ config COMPAT the user helper functions, VFP support and the ptrace interface are handled appropriately by the kernel. - If you also enabled CONFIG_ARM64_64K_PAGES, please be aware that you - will only be able to execute AArch32 binaries that were compiled with - 64k aligned segments. + If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware + that you will only be able to execute AArch32 binaries that were compiled + with page size aligned segments. If you want to execute 32-bit userspace applications, say Y. diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h index da3235494ffd..9b2f5a9d019d 100644 --- a/arch/arm64/include/asm/page.h +++ b/arch/arm64/include/asm/page.h @@ -24,6 +24,9 @@ #ifdef CONFIG_ARM64_64K_PAGES #define PAGE_SHIFT 16 #define CONT_SHIFT 5 +#elif defined(CONFIG_ARM64_16K_PAGES) +#define PAGE_SHIFT 14 +#define CONT_SHIFT 7 #else #define PAGE_SHIFT 12 #define CONT_SHIFT 4 diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index d59cb231a673..4b57e1080538 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -59,6 +59,9 @@ #if defined(CONFIG_ARM64_4K_PAGES) #define ID_AA64MMFR0_TGRAN_SHIFT ID_AA64MMFR0_TGRAN4_SHIFT #define ID_AA64MMFR0_TGRAN_SUPPORTED ID_AA64MMFR0_TGRAN4_SUPPORTED +#elif defined(CONFIG_ARM64_16K_PAGES) +#define ID_AA64MMFR0_TGRAN_SHIFT ID_AA64MMFR0_TGRAN16_SHIFT +#define ID_AA64MMFR0_TGRAN_SUPPORTED ID_AA64MMFR0_TGRAN16_SUPPORTED #elif defined(CONFIG_ARM64_64K_PAGES) #define ID_AA64MMFR0_TGRAN_SHIFT ID_AA64MMFR0_TGRAN64_SHIFT #define ID_AA64MMFR0_TGRAN_SUPPORTED ID_AA64MMFR0_TGRAN64_SUPPORTED diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index 5eac6a2300af..90c7ff233735 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -25,6 +25,8 @@ #ifdef CONFIG_ARM64_4K_PAGES #define THREAD_SIZE_ORDER 2 +#elif defined(CONFIG_ARM64_16K_PAGES) +#define THREAD_SIZE_ORDER 0 #endif #define THREAD_SIZE 16384 diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 5c7e920e4861..6a7d5cd772e6 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -19,6 +19,7 @@ if VIRTUALIZATION config KVM bool "Kernel-based Virtual Machine (KVM) support" depends on OF + depends on !ARM64_16K_PAGES select MMU_NOTIFIER select PREEMPT_NOTIFIERS select ANON_INODES @@ -33,6 +34,8 @@ config KVM select HAVE_KVM_IRQFD ---help--- Support hosting virtualized guest machines. + We don't support KVM with 16K page tables yet, due to the multiple + levels of fake page tables. If unsure, say N. diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 91cb2eaac256..3a4b8b19978b 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -30,7 +30,9 @@ #ifdef CONFIG_ARM64_64K_PAGES #define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K -#else +#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