MIPS: asm: spinlock: Replace "sub" instruction with "addiu"
"sub $reg, imm" is not a real MIPS instruction. The assembler can
replace that with "addi $reg, -imm". However, addi has been removed
from R6, so we replace the "sub" instruction with the "addiu" one.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
diff --git a/arch/mips/include/asm/spinlock.h b/arch/mips/include/asm/spinlock.h
index b523840..b454869 100644
--- a/arch/mips/include/asm/spinlock.h
+++ b/arch/mips/include/asm/spinlock.h
@@ -254,9 +254,6 @@
smp_llsc_mb();
}
-/* Note the use of sub, not subu which will make the kernel die with an
- overflow exception if we ever try to unlock an rwlock that is already
- unlocked or is being held by a writer. */
static inline void arch_read_unlock(arch_rwlock_t *rw)
{
unsigned int tmp;
@@ -266,7 +263,7 @@
if (R10000_LLSC_WAR) {
__asm__ __volatile__(
"1: ll %1, %2 # arch_read_unlock \n"
- " sub %1, 1 \n"
+ " addiu %1, 1 \n"
" sc %1, %0 \n"
" beqzl %1, 1b \n"
: "=" GCC_OFF_SMALL_ASM() (rw->lock), "=&r" (tmp)
@@ -276,7 +273,7 @@
do {
__asm__ __volatile__(
"1: ll %1, %2 # arch_read_unlock \n"
- " sub %1, 1 \n"
+ " addiu %1, -1 \n"
" sc %1, %0 \n"
: "=" GCC_OFF_SMALL_ASM() (rw->lock), "=&r" (tmp)
: GCC_OFF_SMALL_ASM() (rw->lock)