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MIPS: Remove further use of .subsection
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7837314 [MIPS: Get rid of branches to
.subsections] removed most uses of .subsection] removed most uses of
.subsection in inline assembler code.

It left the instances in spinlock.h alone because we knew their use was
in fairly small files where .subsection use was fine but of course this
was a fragile assumption.  LTO breaks this assumption resulting in build
errors due to exceeded branch range, so remove further instances of
.subsection.

The two functions that still use .macro don't currently cause issues
however this use is still fragile.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Ralf Baechle committed Apr 11, 2013
1 parent 9fcb705 commit e01961c
Showing 1 changed file with 44 additions and 72 deletions.
116 changes: 44 additions & 72 deletions arch/mips/include/asm/spinlock.h
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Original file line number Diff line number Diff line change
Expand Up @@ -242,25 +242,16 @@ static inline void arch_read_lock(arch_rwlock_t *rw)
: "m" (rw->lock)
: "memory");
} else {
__asm__ __volatile__(
" .set noreorder # arch_read_lock \n"
"1: ll %1, %2 \n"
" bltz %1, 3f \n"
" addu %1, 1 \n"
"2: sc %1, %0 \n"
" beqz %1, 1b \n"
" nop \n"
" .subsection 2 \n"
"3: ll %1, %2 \n"
" bltz %1, 3b \n"
" addu %1, 1 \n"
" b 2b \n"
" nop \n"
" .previous \n"
" .set reorder \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
: "memory");
do {
__asm__ __volatile__(
"1: ll %1, %2 # arch_read_lock \n"
" bltz %1, 1b \n"
" addu %1, 1 \n"
"2: sc %1, %0 \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
: "memory");
} while (unlikely(!tmp));
}

smp_llsc_mb();
Expand All @@ -285,21 +276,15 @@ static inline void arch_read_unlock(arch_rwlock_t *rw)
: "m" (rw->lock)
: "memory");
} else {
__asm__ __volatile__(
" .set noreorder # arch_read_unlock \n"
"1: ll %1, %2 \n"
" sub %1, 1 \n"
" sc %1, %0 \n"
" beqz %1, 2f \n"
" nop \n"
" .subsection 2 \n"
"2: b 1b \n"
" nop \n"
" .previous \n"
" .set reorder \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
: "memory");
do {
__asm__ __volatile__(
"1: ll %1, %2 # arch_read_unlock \n"
" sub %1, 1 \n"
" sc %1, %0 \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
: "memory");
} while (unlikely(!tmp));
}
}

Expand All @@ -321,25 +306,16 @@ static inline void arch_write_lock(arch_rwlock_t *rw)
: "m" (rw->lock)
: "memory");
} else {
__asm__ __volatile__(
" .set noreorder # arch_write_lock \n"
"1: ll %1, %2 \n"
" bnez %1, 3f \n"
" lui %1, 0x8000 \n"
"2: sc %1, %0 \n"
" beqz %1, 3f \n"
" nop \n"
" .subsection 2 \n"
"3: ll %1, %2 \n"
" bnez %1, 3b \n"
" lui %1, 0x8000 \n"
" b 2b \n"
" nop \n"
" .previous \n"
" .set reorder \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
: "memory");
do {
__asm__ __volatile__(
"1: ll %1, %2 # arch_write_lock \n"
" bnez %1, 1b \n"
" lui %1, 0x8000 \n"
"2: sc %1, %0 \n"
: "=m" (rw->lock), "=&r" (tmp)
: "m" (rw->lock)
: "memory");
} while (unlikely(!tmp));
}

smp_llsc_mb();
Expand Down Expand Up @@ -424,25 +400,21 @@ static inline int arch_write_trylock(arch_rwlock_t *rw)
: "m" (rw->lock)
: "memory");
} else {
__asm__ __volatile__(
" .set noreorder # arch_write_trylock \n"
" li %2, 0 \n"
"1: ll %1, %3 \n"
" bnez %1, 2f \n"
" lui %1, 0x8000 \n"
" sc %1, %0 \n"
" beqz %1, 3f \n"
" li %2, 1 \n"
"2: \n"
__WEAK_LLSC_MB
" .subsection 2 \n"
"3: b 1b \n"
" li %2, 0 \n"
" .previous \n"
" .set reorder \n"
: "=m" (rw->lock), "=&r" (tmp), "=&r" (ret)
: "m" (rw->lock)
: "memory");
do {
__asm__ __volatile__(
" ll %1, %3 # arch_write_trylock \n"
" li %2, 0 \n"
" bnez %1, 2f \n"
" lui %1, 0x8000 \n"
" sc %1, %0 \n"
" li %2, 1 \n"
"2: \n"
: "=m" (rw->lock), "=&r" (tmp), "=&r" (ret)
: "m" (rw->lock)
: "memory");
} while (unlikely(!tmp));

smp_llsc_mb();
}

return ret;
Expand Down

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