From c62a3d7a8de517e0df46e0f4cc46c45f5c44a235 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 1 Dec 2017 17:33:48 +0000 Subject: [PATCH] FROMLIST: arm64: mm: Introduce TTBR_ASID_MASK for getting at the ASID in the TTBR There are now a handful of open-coded masks to extract the ASID from a TTBR value, so introduce a TTBR_ASID_MASK and use that instead. Suggested-by: Mark Rutland Reviewed-by: Mark Rutland Tested-by: Laura Abbott Tested-by: Shanker Donthineni Signed-off-by: Will Deacon (cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git commit b519538dfefc2f8478a1bcb458459c861d431784) Change-Id: I538071c8ec96dca587205c78839c07b6c772fa91 [ghackmann@google.com: adjust context, applying asm-uaccess.h changes to uaccess.h instead] Signed-off-by: Greg Hackmann Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/mmu.h | 1 + arch/arm64/include/asm/uaccess.h | 7 ++++--- arch/arm64/kernel/entry.S | 2 +- 3 files changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h index bb907189aef0..39e502f0ab80 100644 --- a/arch/arm64/include/asm/mmu.h +++ b/arch/arm64/include/asm/mmu.h @@ -17,6 +17,7 @@ #define __ASM_MMU_H #define USER_ASID_FLAG (UL(1) << 48) +#define TTBR_ASID_MASK (UL(0xffff) << 48) #ifndef __ASSEMBLY__ diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index d4383596a38c..57c4bbdf77cc 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -20,6 +20,7 @@ #include #include +#include #include #ifndef __ASSEMBLY__ @@ -149,7 +150,7 @@ static inline void __uaccess_ttbr0_disable(void) write_sysreg(ttbr + SWAPPER_DIR_SIZE, ttbr0_el1); isb(); /* Set reserved ASID */ - ttbr &= ~(0xffffUL << 48); + ttbr &= ~TTBR_ASID_MASK; write_sysreg(ttbr, ttbr1_el1); isb(); } @@ -168,7 +169,7 @@ static inline void __uaccess_ttbr0_enable(void) /* Restore active ASID */ ttbr1 = read_sysreg(ttbr1_el1); - ttbr1 |= ttbr0 & (0xffffUL << 48); + ttbr1 |= ttbr0 & TTBR_ASID_MASK; write_sysreg(ttbr1, ttbr1_el1); isb(); @@ -456,7 +457,7 @@ extern __must_check long strnlen_user(const char __user *str, long n); msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 isb sub \tmp1, \tmp1, #SWAPPER_DIR_SIZE - bic \tmp1, \tmp1, #(0xffff << 48) + bic \tmp1, \tmp1, #TTBR_ASID_MASK msr ttbr1_el1, \tmp1 // set reserved ASID isb .endm diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 60d69614e174..1c7f6f9961a1 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -165,7 +165,7 @@ alternative_else_nop_endif .if \el != 0 mrs x21, ttbr1_el1 - tst x21, #0xffff << 48 // Check for the reserved ASID + tst x21, #TTBR_ASID_MASK // Check for the reserved ASID orr x23, x23, #PSR_PAN_BIT // Set the emulated PAN in the saved SPSR b.eq 1f // TTBR0 access already disabled and x23, x23, #~PSR_PAN_BIT // Clear the emulated PAN in the saved SPSR -- 2.20.1