From 378ed6f0e3c525e3b12827e7b7fb0a078ee48a32 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Thu, 8 Nov 2018 20:14:38 +0000 Subject: MIPS: Avoid using .set mips0 to restore ISA We currently have 2 commonly used methods for switching ISA within assembly code, then restoring the original ISA. 1) Using a pair of .set push & .set pop directives. For example: .set push .set mips32r2 .set pop 2) Using .set mips0 to restore the ISA originally specified on the command line. For example: .set mips32r2 .set mips0 Unfortunately method 2 does not work with nanoMIPS toolchains, where the assembler rejects the .set mips0 directive like so: Error: cannot change ISA from nanoMIPS to mips0 In preparation for supporting nanoMIPS builds, switch all instances of method 2 in generic non-platform-specific code to use push & pop as in method 1 instead. The .set push & .set pop is arguably cleaner anyway, and if nothing else it's good to consistently use one method. Signed-off-by: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/21037/ Cc: linux-mips@linux-mips.org --- arch/mips/include/asm/kvm_host.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'arch/mips/include/asm/kvm_host.h') diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h index 2c1c53d12179..e445026858bc 100644 --- a/arch/mips/include/asm/kvm_host.h +++ b/arch/mips/include/asm/kvm_host.h @@ -411,11 +411,12 @@ static inline void _kvm_atomic_set_c0_guest_reg(unsigned long *reg, unsigned long temp; do { __asm__ __volatile__( + " .set push \n" " .set "MIPS_ISA_ARCH_LEVEL" \n" " " __LL "%0, %1 \n" " or %0, %2 \n" " " __SC "%0, %1 \n" - " .set mips0 \n" + " .set pop \n" : "=&r" (temp), "+m" (*reg) : "r" (val)); } while (unlikely(!temp)); @@ -427,11 +428,12 @@ static inline void _kvm_atomic_clear_c0_guest_reg(unsigned long *reg, unsigned long temp; do { __asm__ __volatile__( + " .set push \n" " .set "MIPS_ISA_ARCH_LEVEL" \n" " " __LL "%0, %1 \n" " and %0, %2 \n" " " __SC "%0, %1 \n" - " .set mips0 \n" + " .set pop \n" : "=&r" (temp), "+m" (*reg) : "r" (~val)); } while (unlikely(!temp)); @@ -444,12 +446,13 @@ static inline void _kvm_atomic_change_c0_guest_reg(unsigned long *reg, unsigned long temp; do { __asm__ __volatile__( + " .set push \n" " .set "MIPS_ISA_ARCH_LEVEL" \n" " " __LL "%0, %1 \n" " and %0, %2 \n" " or %0, %3 \n" " " __SC "%0, %1 \n" - " .set mips0 \n" + " .set pop \n" : "=&r" (temp), "+m" (*reg) : "r" (~change), "r" (val & change)); } while (unlikely(!temp)); -- cgit v1.2.3