From b6d00d47e81a49f6cf462518c10408f37a3e6785 Mon Sep 17 00:00:00 2001 From: Steve Capper Date: Wed, 7 Aug 2019 16:55:22 +0100 Subject: [PATCH] arm64: mm: Introduce 52-bit Kernel VAs Most of the machinery is now in place to enable 52-bit kernel VAs that are detectable at boot time. This patch adds a Kconfig option for 52-bit user and kernel addresses and plumbs in the requisite CONFIG_ macros as well as sets TCR.T1SZ, physvirt_offset and vmemmap at early boot. To simplify things this patch also removes the 52-bit user/48-bit kernel kconfig option. Signed-off-by: Steve Capper Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon --- arch/arm64/Kconfig | 20 +++++++++++--------- arch/arm64/include/asm/assembler.h | 13 ++++++++----- arch/arm64/include/asm/memory.h | 7 ++++--- arch/arm64/include/asm/mmu_context.h | 2 +- arch/arm64/include/asm/pgtable-hwdef.h | 2 +- arch/arm64/kernel/head.S | 4 ++-- arch/arm64/mm/init.c | 10 ++++++++++ arch/arm64/mm/proc.S | 3 ++- 8 files changed, 39 insertions(+), 22 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index f7f23e47c28f..f5f7cb75a698 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -286,7 +286,7 @@ config PGTABLE_LEVELS int 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_USER_VA_BITS_52) + default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 @@ -300,12 +300,12 @@ config ARCH_PROC_KCORE_TEXT config KASAN_SHADOW_OFFSET hex depends on KASAN - default 0xdfffa00000000000 if (ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52) && !KASAN_SW_TAGS + default 0xdfffa00000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS default 0xdfffd00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS default 0xdffffe8000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS default 0xdfffffd000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS default 0xdffffffa00000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS - default 0xefff900000000000 if (ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52) && KASAN_SW_TAGS + default 0xefff900000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS default 0xefffc80000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS default 0xeffffe4000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS default 0xefffffc800000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS @@ -759,13 +759,14 @@ config ARM64_VA_BITS_47 config ARM64_VA_BITS_48 bool "48-bit" -config ARM64_USER_VA_BITS_52 - bool "52-bit (user)" +config ARM64_VA_BITS_52 + bool "52-bit" depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) help Enable 52-bit virtual addressing for userspace when explicitly - requested via a hint to mmap(). The kernel will continue to - use 48-bit virtual addresses for its own mappings. + requested via a hint to mmap(). The kernel will also use 52-bit + virtual addresses for its own mappings (provided HW support for + this feature is available, otherwise it reverts to 48-bit). NOTE: Enabling 52-bit virtual addressing in conjunction with ARMv8.3 Pointer Authentication will result in the PAC being @@ -778,7 +779,7 @@ endchoice config ARM64_FORCE_52BIT bool "Force 52-bit virtual addresses for userspace" - depends on ARM64_USER_VA_BITS_52 && EXPERT + depends on ARM64_VA_BITS_52 && EXPERT help For systems with 52-bit userspace VAs enabled, the kernel will attempt to maintain compatibility with older software by providing 48-bit VAs @@ -795,7 +796,8 @@ config ARM64_VA_BITS 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 || ARM64_USER_VA_BITS_52 + default 48 if ARM64_VA_BITS_48 + default 52 if ARM64_VA_BITS_52 choice prompt "Physical address space size" diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index ede368bafa2c..c066fc4976cd 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -349,6 +349,13 @@ alternative_endif bfi \valreg, \t0sz, #TCR_T0SZ_OFFSET, #TCR_TxSZ_WIDTH .endm +/* + * tcr_set_t1sz - update TCR.T1SZ + */ + .macro tcr_set_t1sz, valreg, t1sz + bfi \valreg, \t1sz, #TCR_T1SZ_OFFSET, #TCR_TxSZ_WIDTH + .endm + /* * tcr_compute_pa_size - set TCR.(I)PS to the highest supported * ID_AA64MMFR0_EL1.PARange value @@ -539,10 +546,6 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU * ttbr: Value of ttbr to set, modified. */ .macro offset_ttbr1, ttbr, tmp -#ifdef CONFIG_ARM64_USER_VA_BITS_52 - orr \ttbr, \ttbr, #TTBR1_BADDR_4852_OFFSET -#endif - #ifdef CONFIG_ARM64_VA_BITS_52 mrs_s \tmp, SYS_ID_AA64MMFR2_EL1 and \tmp, \tmp, #(0xf << ID_AA64MMFR2_LVA_SHIFT) @@ -558,7 +561,7 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU * to be nop'ed out when dealing with 52-bit kernel VAs. */ .macro restore_ttbr1, ttbr -#if defined(CONFIG_ARM64_USER_VA_BITS_52) || defined(CONFIG_ARM64_VA_BITS_52) +#ifdef CONFIG_ARM64_VA_BITS_52 bic \ttbr, \ttbr, #TTBR1_BADDR_4852_OFFSET #endif .endm diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 0204c2006c92..d911d0573460 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -44,8 +44,9 @@ * VA_START - the first kernel virtual address. */ #define VA_BITS (CONFIG_ARM64_VA_BITS) -#define PAGE_OFFSET (UL(0xffffffffffffffff) - \ - (UL(1) << VA_BITS) + 1) +#define _PAGE_OFFSET(va) (UL(0xffffffffffffffff) - \ + (UL(1) << (va)) + 1) +#define PAGE_OFFSET (_PAGE_OFFSET(VA_BITS)) #define KIMAGE_VADDR (MODULES_END) #define BPF_JIT_REGION_START (KASAN_SHADOW_END) #define BPF_JIT_REGION_SIZE (SZ_128M) @@ -68,7 +69,7 @@ #define KERNEL_START _text #define KERNEL_END _end -#ifdef CONFIG_ARM64_USER_VA_BITS_52 +#ifdef CONFIG_ARM64_VA_BITS_52 #define MAX_USER_VA_BITS 52 #else #define MAX_USER_VA_BITS VA_BITS diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h index 670003a55d28..3827ff4040a3 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -63,7 +63,7 @@ extern u64 idmap_ptrs_per_pgd; static inline bool __cpu_uses_extended_idmap(void) { - if (IS_ENABLED(CONFIG_ARM64_USER_VA_BITS_52)) + if (IS_ENABLED(CONFIG_ARM64_VA_BITS_52)) return false; return unlikely(idmap_t0sz != TCR_T0SZ(VA_BITS)); diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index db92950bb1a0..3df60f97da1f 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -304,7 +304,7 @@ #define TTBR_BADDR_MASK_52 (((UL(1) << 46) - 1) << 2) #endif -#ifdef CONFIG_ARM64_USER_VA_BITS_52 +#ifdef CONFIG_ARM64_VA_BITS_52 /* Must be at least 64-byte aligned to prevent corruption of the TTBR */ #define TTBR1_BADDR_4852_OFFSET (((UL(1) << (52 - PGDIR_SHIFT)) - \ (UL(1) << (48 - PGDIR_SHIFT))) * 8) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index a96dc4386c7c..c8446f8c81f5 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -308,7 +308,7 @@ __create_page_tables: adrp x0, idmap_pg_dir adrp x3, __idmap_text_start // __pa(__idmap_text_start) -#ifdef CONFIG_ARM64_USER_VA_BITS_52 +#ifdef CONFIG_ARM64_VA_BITS_52 mrs_s x6, SYS_ID_AA64MMFR2_EL1 and x6, x6, #(0xf << ID_AA64MMFR2_LVA_SHIFT) mov x5, #52 @@ -794,7 +794,7 @@ ENTRY(__enable_mmu) ENDPROC(__enable_mmu) ENTRY(__cpu_secondary_check52bitva) -#ifdef CONFIG_ARM64_USER_VA_BITS_52 +#ifdef CONFIG_ARM64_VA_BITS_52 ldr_l x0, vabits_user cmp x0, #52 b.ne 2f diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 2940221e5519..531c497c5758 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -325,6 +325,16 @@ void __init arm64_memblock_init(void) vmemmap = ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT)); + /* + * If we are running with a 52-bit kernel VA config on a system that + * does not support it, we have to offset our vmemmap and physvirt_offset + * s.t. we avoid the 52-bit portion of the direct linear map + */ + if (IS_ENABLED(CONFIG_ARM64_VA_BITS_52) && (vabits_actual != 52)) { + vmemmap += (_PAGE_OFFSET(48) - _PAGE_OFFSET(52)) >> PAGE_SHIFT; + physvirt_offset = PHYS_OFFSET - _PAGE_OFFSET(48); + } + /* * Remove the memory that we will not be able to cover with the * linear mapping. Take care not to clip the kernel which may be diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 8d289ff7584d..8b021c5c0884 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -438,10 +438,11 @@ ENTRY(__cpu_setup) TCR_TBI0 | TCR_A1 | TCR_KASAN_FLAGS tcr_clear_errata_bits x10, x9, x5 -#ifdef CONFIG_ARM64_USER_VA_BITS_52 +#ifdef CONFIG_ARM64_VA_BITS_52 ldr_l x9, vabits_user sub x9, xzr, x9 add x9, x9, #64 + tcr_set_t1sz x10, x9 #else ldr_l x9, idmap_t0sz #endif