From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Capper Subject: [PATCH 12/12] arm64: mm: Add 48/52-bit kernel VA support Date: Mon, 4 Dec 2017 14:13:13 +0000 Message-ID: <20171204141313.31604-13-steve.capper@arm.com> References: <20171204141313.31604-1-steve.capper@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 69D3A49D27 for ; Mon, 4 Dec 2017 09:11:02 -0500 (EST) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id nBT4nynXQtfJ for ; Mon, 4 Dec 2017 09:10:52 -0500 (EST) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 2079149D95 for ; Mon, 4 Dec 2017 09:10:43 -0500 (EST) In-Reply-To: <20171204141313.31604-1-steve.capper@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Cc: catalin.marinas@arm.com, ard.biesheuvel@linaro.org List-Id: kvmarm@lists.cs.columbia.edu Add the option to use 52-bit VA support upon availability at boot. We use the same KASAN_SHADOW_OFFSET for both 48 and 52 bit VA spaces as in both cases the start and end of the KASAN shadow region are PGD aligned. >>From ID_AA64MMFR2, we check the LVA field on very early boot and set the VA size, PGDIR_SHIFT and TCR.T[01]SZ values which then influence how the rest of the memory system behaves. Note that userspace addresses will still be capped out at 48-bit. More patches are needed to deal with scenarios where the user provides MMAP_FIXED hint and a high address to mmap. Signed-off-by: Steve Capper --- arch/arm64/Kconfig | 8 ++++++++ arch/arm64/include/asm/memory.h | 5 +++++ arch/arm64/mm/kasan_init.c | 3 +++ arch/arm64/mm/proc.S | 21 +++++++++++++++++++++ 4 files changed, 37 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 143c453b06f1..be65dd4bb109 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -262,6 +262,7 @@ config PGTABLE_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 + default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48_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 @@ -275,6 +276,7 @@ config ARCH_PROC_KCORE_TEXT config KASAN_SHADOW_OFFSET hex depends on KASAN + default 0xdfffa00000000000 if ARM64_VA_BITS_48_52 default 0xdfffa00000000000 if ARM64_VA_BITS_48 default 0xdfffd00000000000 if ARM64_VA_BITS_47 default 0xdffffe8000000000 if ARM64_VA_BITS_42 @@ -646,6 +648,10 @@ config ARM64_VA_BITS_47 config ARM64_VA_BITS_48 bool "48-bit" +config ARM64_VA_BITS_48_52 + bool "48 or 52-bit (decided at boot time)" + depends on ARM64_64K_PAGES + endchoice config ARM64_VA_BITS @@ -655,9 +661,11 @@ config ARM64_VA_BITS default 42 if ARM64_VA_BITS_42 default 47 if ARM64_VA_BITS_47 default 48 if ARM64_VA_BITS_48 + default 48 if ARM64_VA_BITS_48_52 config ARM64_VA_BITS_ALT bool + default y if ARM64_VA_BITS_48_52 default n config CPU_BIG_ENDIAN diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 652ae83468b6..8530f8eb77da 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -72,6 +72,11 @@ #define PCI_IO_START (PCI_IO_END - PCI_IO_SIZE) #define FIXADDR_TOP (PCI_IO_START - PGDIR_SIZE) #define VMEMMAP_START (FIXADDR_START - VMEMMAP_SIZE) +#define VA_BITS_MIN (CONFIG_ARM64_VA_BITS) + +#ifdef CONFIG_ARM64_VA_BITS_48_52 +#define VA_BITS_ALT (52) +#endif #define KERNEL_START _text #define KERNEL_END _end diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 33f99e18e4ff..38c933c17f82 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -135,6 +135,9 @@ static void __init kasan_pgd_populate(unsigned long addr, unsigned long end, /* The early shadow maps everything to a single page of zeroes */ asmlinkage void __init kasan_early_init(void) { +#ifdef CONFIG_ARM64_VA_BITS_ALT + BUILD_BUG_ON(!IS_ALIGNED(_KASAN_SHADOW_START(VA_BITS_ALT), PGDIR_SIZE)); +#endif BUILD_BUG_ON(!IS_ALIGNED(_KASAN_SHADOW_START(VA_BITS_MIN), PGDIR_SIZE)); BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PGDIR_SIZE)); kasan_pgd_populate(KASAN_SHADOW_START, KASAN_SHADOW_END, NUMA_NO_NODE, diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 607a6ff0e205..42a91a4a1126 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -225,6 +225,14 @@ ENTRY(__cpu_setup) */ ldr x10, =TCR_TxSZ(VA_BITS_MIN) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \ TCR_TG_FLAGS | TCR_ASID16 | TCR_TBI0 +#ifdef CONFIG_ARM64_VA_BITS_ALT + ldr_l x9, vabits_actual + cmp x9, #VA_BITS_ALT + b.ne 1f + ldr x10, =TCR_TxSZ(VA_BITS_ALT) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \ + TCR_TG_FLAGS | TCR_ASID16 | TCR_TBI0 +1: +#endif tcr_set_idmap_t0sz x10, x9 /* @@ -251,9 +259,22 @@ ENTRY(__cpu_setup) ENDPROC(__cpu_setup) ENTRY(__setup_va_constants) +#ifdef CONFIG_ARM64_VA_BITS_48_52 + mrs_s x5, SYS_ID_AA64MMFR2_EL1 + and x5, x5, #0xf << ID_AA64MMFR2_LVA_SHIFT + cmp x5, #1 << ID_AA64MMFR2_LVA_SHIFT + b.ne 1f + mov x0, #VA_BITS_ALT + mov x1, TCR_T0SZ(VA_BITS_ALT) + mov x2, #1 << (VA_BITS_ALT - PGDIR_SHIFT) + b 2f +#endif + +1: mov x0, #VA_BITS_MIN mov x1, TCR_T0SZ(VA_BITS_MIN) mov x2, #1 << (VA_BITS_MIN - PGDIR_SHIFT) +2: str_l x0, vabits_actual, x5 str_l x1, idmap_t0sz, x5 str_l x2, ptrs_per_pgd, x5 -- 2.11.0