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/kernel/syscall.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'arch/mips/kernel/syscall.c') diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c index 69c17b549fd3..41a0db08cd37 100644 --- a/arch/mips/kernel/syscall.c +++ b/arch/mips/kernel/syscall.c @@ -106,6 +106,7 @@ static inline int mips_atomic_set(unsigned long addr, unsigned long new) if (cpu_has_llsc && R10000_LLSC_WAR) { __asm__ __volatile__ ( + " .set push \n" " .set arch=r4000 \n" " li %[err], 0 \n" "1: ll %[old], (%[addr]) \n" @@ -122,7 +123,7 @@ static inline int mips_atomic_set(unsigned long addr, unsigned long new) " "STR(PTR)" 1b, 4b \n" " "STR(PTR)" 2b, 4b \n" " .previous \n" - " .set mips0 \n" + " .set pop \n" : [old] "=&r" (old), [err] "=&r" (err), [tmp] "=&r" (tmp) @@ -132,6 +133,7 @@ static inline int mips_atomic_set(unsigned long addr, unsigned long new) : "memory"); } else if (cpu_has_llsc) { __asm__ __volatile__ ( + " .set push \n" " .set "MIPS_ISA_ARCH_LEVEL" \n" " li %[err], 0 \n" "1: \n" @@ -150,7 +152,7 @@ static inline int mips_atomic_set(unsigned long addr, unsigned long new) " "STR(PTR)" 1b, 5b \n" " "STR(PTR)" 2b, 5b \n" " .previous \n" - " .set mips0 \n" + " .set pop \n" : [old] "=&r" (old), [err] "=&r" (err), [tmp] "=&r" (tmp) -- cgit v1.2.3