#ifndef _ASM_SPINLOCK_H
#define _ASM_SPINLOCK_H
-#error SMP spinlocks not implemented for MN10300
+#include <asm/atomic.h>
+#include <asm/rwlock.h>
+#include <asm/page.h>
+/*
+ * Simple spin lock operations. There are two variants, one clears IRQ's
+ * on the local processor, one does not.
+ *
+ * We make no fairness assumptions. They have a cost.
+ */
+
+#define arch_spin_is_locked(x) (*(volatile signed char *)(&(x)->slock) != 0)
+#define arch_spin_unlock_wait(x) do { barrier(); } while (arch_spin_is_locked(x))
+
+static inline void arch_spin_unlock(arch_spinlock_t *lock)
+{
+ asm volatile(
+ " bclr 1,(0,%0) \n"
+ :
+ : "a"(&lock->slock)
+ : "memory", "cc");
+}
+
+static inline int arch_spin_trylock(arch_spinlock_t *lock)
+{
+ int ret;
+
+ asm volatile(
+ " mov 1,%0 \n"
+ " bset %0,(%1) \n"
+ " bne 1f \n"
+ " clr %0 \n"
+ "1: xor 1,%0 \n"
+ : "=d"(ret)
+ : "a"(&lock->slock)
+ : "memory", "cc");
+
+ return ret;
+}
+
+static inline void arch_spin_lock(arch_spinlock_t *lock)
+{
+ asm volatile(
+ "1: bset 1,(0,%0) \n"
+ " bne 1b \n"
+ :
+ : "a"(&lock->slock)
+ : "memory", "cc");
+}
+
+static inline void arch_spin_lock_flags(arch_spinlock_t *lock,
+ unsigned long flags)
+{
+ int temp;
+
+ asm volatile(
+ "1: bset 1,(0,%2) \n"
+ " beq 3f \n"
+ " mov %1,epsw \n"
+ "2: mov (0,%2),%0 \n"
+ " or %0,%0 \n"
+ " bne 2b \n"
+ " mov %3,%0 \n"
+ " mov %0,epsw \n"
+ " nop \n"
+ " nop \n"
+ " bra 1b\n"
+ "3: \n"
+ : "=&d" (temp)
+ : "d" (flags), "a"(&lock->slock), "i"(EPSW_IE | MN10300_CLI_LEVEL)
+ : "memory", "cc");
+}
+
+#ifdef __KERNEL__
+
+/*
+ * Read-write spinlocks, allowing multiple readers
+ * but only one writer.
+ *
+ * NOTE! it is quite common to have readers in interrupts
+ * but no interrupt writers. For those circumstances we
+ * can "mix" irq-safe locks - any writer needs to get a
+ * irq-safe write-lock, but readers can get non-irqsafe
+ * read-locks.
+ */
+
+/**
+ * read_can_lock - would read_trylock() succeed?
+ * @lock: the rwlock in question.
+ */
+#define arch_read_can_lock(x) ((int)(x)->lock > 0)
+
+/**
+ * write_can_lock - would write_trylock() succeed?
+ * @lock: the rwlock in question.
+ */
+#define arch_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS)
+
+/*
+ * On mn10300, we implement read-write locks as a 32-bit counter
+ * with the high bit (sign) being the "contended" bit.
+ */
+static inline void arch_read_lock(arch_rwlock_t *rw)
+{
+#if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
+ __build_read_lock(rw, "__read_lock_failed");
+#else
+ {
+ atomic_t *count = (atomic_t *)rw;
+ while (atomic_dec_return(count) < 0)
+ atomic_inc(count);
+ }
+#endif
+}
+
+static inline void arch_write_lock(arch_rwlock_t *rw)
+{
+#if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
+ __build_write_lock(rw, "__write_lock_failed");
+#else
+ {
+ atomic_t *count = (atomic_t *)rw;
+ while (!atomic_sub_and_test(RW_LOCK_BIAS, count))
+ atomic_add(RW_LOCK_BIAS, count);
+ }
+#endif
+}
+
+static inline void arch_read_unlock(arch_rwlock_t *rw)
+{
+#if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
+ __build_read_unlock(rw);
+#else
+ {
+ atomic_t *count = (atomic_t *)rw;
+ atomic_inc(count);
+ }
+#endif
+}
+
+static inline void arch_write_unlock(arch_rwlock_t *rw)
+{
+#if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
+ __build_write_unlock(rw);
+#else
+ {
+ atomic_t *count = (atomic_t *)rw;
+ atomic_add(RW_LOCK_BIAS, count);
+ }
+#endif
+}
+
+static inline int arch_read_trylock(arch_rwlock_t *lock)
+{
+ atomic_t *count = (atomic_t *)lock;
+ atomic_dec(count);
+ if (atomic_read(count) >= 0)
+ return 1;
+ atomic_inc(count);
+ return 0;
+}
+
+static inline int arch_write_trylock(arch_rwlock_t *lock)
+{
+ atomic_t *count = (atomic_t *)lock;
+ if (atomic_sub_and_test(RW_LOCK_BIAS, count))
+ return 1;
+ atomic_add(RW_LOCK_BIAS, count);
+ return 0;
+}
+
+#define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
+#define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
+
+#define _raw_spin_relax(lock) cpu_relax()
+#define _raw_read_relax(lock) cpu_relax()
+#define _raw_write_relax(lock) cpu_relax()
+
+#endif /* __KERNEL__ */
#endif /* _ASM_SPINLOCK_H */
git.openpandora.org / pandora-kernel.git / blobdiff