From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59770 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423530AbeBOPj3 (ORCPT ); Thu, 15 Feb 2018 10:39:29 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Rutland , Laura Abbott , Shanker Donthineni , Will Deacon Subject: [PATCH 4.15 022/202] [Variant 3/Meltdown] arm64: mm: Add arm64_kernel_unmapped_at_el0 helper Date: Thu, 15 Feb 2018 16:15:22 +0100 Message-Id: <20180215151714.063533844@linuxfoundation.org> In-Reply-To: <20180215151712.768794354@linuxfoundation.org> References: <20180215151712.768794354@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon Commit fc0e1299da54 upstream. In order for code such as TLB invalidation to operate efficiently when the decision to map the kernel at EL0 is determined at runtime, this patch introduces a helper function, arm64_kernel_unmapped_at_el0, to determine whether or not the kernel is mapped whilst running in userspace. Currently, this just reports the value of CONFIG_UNMAP_KERNEL_AT_EL0, but will later be hooked up to a fake CPU capability using a static key. Reviewed-by: Mark Rutland Tested-by: Laura Abbott Tested-by: Shanker Donthineni Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/mmu.h | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/arch/arm64/include/asm/mmu.h +++ b/arch/arm64/include/asm/mmu.h @@ -19,6 +19,8 @@ #define MMCF_AARCH32 0x1 /* mm context flag for AArch32 executables */ #define USER_ASID_FLAG (UL(1) << 48) +#ifndef __ASSEMBLY__ + typedef struct { atomic64_t id; void *vdso; @@ -32,6 +34,11 @@ typedef struct { */ #define ASID(mm) ((mm)->context.id.counter & 0xffff) +static inline bool arm64_kernel_unmapped_at_el0(void) +{ + return IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0); +} + extern void paging_init(void); extern void bootmem_init(void); extern void __iomem *early_io_map(phys_addr_t phys, unsigned long virt); @@ -42,4 +49,5 @@ extern void create_pgd_mapping(struct mm extern void *fixmap_remap_fdt(phys_addr_t dt_phys); extern void mark_linear_text_alias_ro(void); +#endif /* !__ASSEMBLY__ */ #endif