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parisc: Improve interrupt handling in arch_spin_lock_flags()

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Rewrite arch_spin_lock() and arch_spin_lock_flags() to not re-enable and
disable the PSW_SM_I interrupt flag too often.

Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Helge Deller 2020-04-05 22:08:07 +02:00
parent 997ba65736
commit 2772f0efd5
1 changed files with 19 additions and 10 deletions
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29
arch/parisc/include/asm/spinlock.h
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@ -10,25 +10,34 @@
static inline int arch_spin_is_locked(arch_spinlock_t *x) static inline int arch_spin_is_locked(arch_spinlock_t *x)
{ {
volatile unsigned int *a = __ldcw_align(x); volatile unsigned int *a = __ldcw_align(x);
smp_mb();
return *a == 0; return *a == 0;
} }
#define arch_spin_lock(lock) arch_spin_lock_flags(lock, 0) static inline void arch_spin_lock(arch_spinlock_t *x)
static inline void arch_spin_lock_flags(arch_spinlock_t *x,
unsigned long flags)
{ {
volatile unsigned int *a; volatile unsigned int *a;
a = __ldcw_align(x); a = __ldcw_align(x);
while (__ldcw(a) == 0) while (__ldcw(a) == 0)
while (*a == 0) while (*a == 0)
if (flags & PSW_SM_I) { cpu_relax();
local_irq_enable(); }
cpu_relax();
local_irq_disable(); static inline void arch_spin_lock_flags(arch_spinlock_t *x,
} else unsigned long flags)
cpu_relax(); {
volatile unsigned int *a;
unsigned long flags_dis;
a = __ldcw_align(x);
while (__ldcw(a) == 0) {
local_save_flags(flags_dis);
local_irq_restore(flags);
while (*a == 0)
cpu_relax();
local_irq_restore(flags_dis);
}
} }
#define arch_spin_lock_flags arch_spin_lock_flags #define arch_spin_lock_flags arch_spin_lock_flags