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Inital import
[l4.git] / l4 / pkg / linux-26-headers / include / asm-m32r / spinlock.h
diff --git a/l4/pkg/linux-26-headers/include/asm-m32r/spinlock.h b/l4/pkg/linux-26-headers/include/asm-m32r/spinlock.h
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+#ifndef _ASM_M32R_SPINLOCK_H
+#define _ASM_M32R_SPINLOCK_H
+
+/*
+ *  linux/include/asm-m32r/spinlock.h
+ *
+ *  M32R version:
+ *    Copyright (C) 2001, 2002  Hitoshi Yamamoto
+ *    Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
+ */
+
+#include <linux/compiler.h>
+#include <asm/atomic.h>
+#include <asm/page.h>
+
+/*
+ * Your basic SMP spinlocks, allowing only a single CPU anywhere
+ *
+ * (the type definitions are in asm/spinlock_types.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 __raw_spin_is_locked(x)                (*(volatile int *)(&(x)->slock) <= 0)
+#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
+#define __raw_spin_unlock_wait(x) \
+               do { cpu_relax(); } while (__raw_spin_is_locked(x))
+
+/**
+ * __raw_spin_trylock - Try spin lock and return a result
+ * @lock: Pointer to the lock variable
+ *
+ * __raw_spin_trylock() tries to get the lock and returns a result.
+ * On the m32r, the result value is 1 (= Success) or 0 (= Failure).
+ */
+static inline int __raw_spin_trylock(raw_spinlock_t *lock)
+{
+       int oldval;
+       unsigned long tmp1, tmp2;
+
+       /*
+        * lock->slock :  =1 : unlock
+        *             : <=0 : lock
+        * {
+        *   oldval = lock->slock; <--+ need atomic operation
+        *   lock->slock = 0;      <--+
+        * }
+        */
+       __asm__ __volatile__ (
+               "# __raw_spin_trylock           \n\t"
+               "ldi    %1, #0;                 \n\t"
+               "mvfc   %2, psw;                \n\t"
+               "clrpsw #0x40 -> nop;           \n\t"
+               DCACHE_CLEAR("%0", "r6", "%3")
+               "lock   %0, @%3;                \n\t"
+               "unlock %1, @%3;                \n\t"
+               "mvtc   %2, psw;                \n\t"
+               : "=&r" (oldval), "=&r" (tmp1), "=&r" (tmp2)
+               : "r" (&lock->slock)
+               : "memory"
+#ifdef CONFIG_CHIP_M32700_TS1
+               , "r6"
+#endif /* CONFIG_CHIP_M32700_TS1 */
+       );
+
+       return (oldval > 0);
+}
+
+static inline void __raw_spin_lock(raw_spinlock_t *lock)
+{
+       unsigned long tmp0, tmp1;
+
+       /*
+        * lock->slock :  =1 : unlock
+        *             : <=0 : lock
+        *
+        * for ( ; ; ) {
+        *   lock->slock -= 1;  <-- need atomic operation
+        *   if (lock->slock == 0) break;
+        *   for ( ; lock->slock <= 0 ; );
+        * }
+        */
+       __asm__ __volatile__ (
+               "# __raw_spin_lock              \n\t"
+               ".fillinsn                      \n"
+               "1:                             \n\t"
+               "mvfc   %1, psw;                \n\t"
+               "clrpsw #0x40 -> nop;           \n\t"
+               DCACHE_CLEAR("%0", "r6", "%2")
+               "lock   %0, @%2;                \n\t"
+               "addi   %0, #-1;                \n\t"
+               "unlock %0, @%2;                \n\t"
+               "mvtc   %1, psw;                \n\t"
+               "bltz   %0, 2f;                 \n\t"
+               LOCK_SECTION_START(".balign 4 \n\t")
+               ".fillinsn                      \n"
+               "2:                             \n\t"
+               "ld     %0, @%2;                \n\t"
+               "bgtz   %0, 1b;                 \n\t"
+               "bra    2b;                     \n\t"
+               LOCK_SECTION_END
+               : "=&r" (tmp0), "=&r" (tmp1)
+               : "r" (&lock->slock)
+               : "memory"
+#ifdef CONFIG_CHIP_M32700_TS1
+               , "r6"
+#endif /* CONFIG_CHIP_M32700_TS1 */
+       );
+}
+
+static inline void __raw_spin_unlock(raw_spinlock_t *lock)
+{
+       mb();
+       lock->slock = 1;
+}
+
+/*
+ * 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.
+ *
+ * On x86, we implement read-write locks as a 32-bit counter
+ * with the high bit (sign) being the "contended" bit.
+ *
+ * The inline assembly is non-obvious. Think about it.
+ *
+ * Changed to use the same technique as rw semaphores.  See
+ * semaphore.h for details.  -ben
+ */
+
+/**
+ * read_can_lock - would read_trylock() succeed?
+ * @lock: the rwlock in question.
+ */
+#define __raw_read_can_lock(x) ((int)(x)->lock > 0)
+
+/**
+ * write_can_lock - would write_trylock() succeed?
+ * @lock: the rwlock in question.
+ */
+#define __raw_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS)
+
+static inline void __raw_read_lock(raw_rwlock_t *rw)
+{
+       unsigned long tmp0, tmp1;
+
+       /*
+        * rw->lock :  >0 : unlock
+        *          : <=0 : lock
+        *
+        * for ( ; ; ) {
+        *   rw->lock -= 1;  <-- need atomic operation
+        *   if (rw->lock >= 0) break;
+        *   rw->lock += 1;  <-- need atomic operation
+        *   for ( ; rw->lock <= 0 ; );
+        * }
+        */
+       __asm__ __volatile__ (
+               "# read_lock                    \n\t"
+               ".fillinsn                      \n"
+               "1:                             \n\t"
+               "mvfc   %1, psw;                \n\t"
+               "clrpsw #0x40 -> nop;           \n\t"
+               DCACHE_CLEAR("%0", "r6", "%2")
+               "lock   %0, @%2;                \n\t"
+               "addi   %0, #-1;                \n\t"
+               "unlock %0, @%2;                \n\t"
+               "mvtc   %1, psw;                \n\t"
+               "bltz   %0, 2f;                 \n\t"
+               LOCK_SECTION_START(".balign 4 \n\t")
+               ".fillinsn                      \n"
+               "2:                             \n\t"
+               "clrpsw #0x40 -> nop;           \n\t"
+               DCACHE_CLEAR("%0", "r6", "%2")
+               "lock   %0, @%2;                \n\t"
+               "addi   %0, #1;                 \n\t"
+               "unlock %0, @%2;                \n\t"
+               "mvtc   %1, psw;                \n\t"
+               ".fillinsn                      \n"
+               "3:                             \n\t"
+               "ld     %0, @%2;                \n\t"
+               "bgtz   %0, 1b;                 \n\t"
+               "bra    3b;                     \n\t"
+               LOCK_SECTION_END
+               : "=&r" (tmp0), "=&r" (tmp1)
+               : "r" (&rw->lock)
+               : "memory"
+#ifdef CONFIG_CHIP_M32700_TS1
+               , "r6"
+#endif /* CONFIG_CHIP_M32700_TS1 */
+       );
+}
+
+static inline void __raw_write_lock(raw_rwlock_t *rw)
+{
+       unsigned long tmp0, tmp1, tmp2;
+
+       /*
+        * rw->lock :  =RW_LOCK_BIAS_STR : unlock
+        *          : !=RW_LOCK_BIAS_STR : lock
+        *
+        * for ( ; ; ) {
+        *   rw->lock -= RW_LOCK_BIAS_STR;  <-- need atomic operation
+        *   if (rw->lock == 0) break;
+        *   rw->lock += RW_LOCK_BIAS_STR;  <-- need atomic operation
+        *   for ( ; rw->lock != RW_LOCK_BIAS_STR ; ) ;
+        * }
+        */
+       __asm__ __volatile__ (
+               "# write_lock                                   \n\t"
+               "seth   %1, #high(" RW_LOCK_BIAS_STR ");        \n\t"
+               "or3    %1, %1, #low(" RW_LOCK_BIAS_STR ");     \n\t"
+               ".fillinsn                                      \n"
+               "1:                                             \n\t"
+               "mvfc   %2, psw;                                \n\t"
+               "clrpsw #0x40 -> nop;                           \n\t"
+               DCACHE_CLEAR("%0", "r7", "%3")
+               "lock   %0, @%3;                                \n\t"
+               "sub    %0, %1;                                 \n\t"
+               "unlock %0, @%3;                                \n\t"
+               "mvtc   %2, psw;                                \n\t"
+               "bnez   %0, 2f;                                 \n\t"
+               LOCK_SECTION_START(".balign 4 \n\t")
+               ".fillinsn                                      \n"
+               "2:                                             \n\t"
+               "clrpsw #0x40 -> nop;                           \n\t"
+               DCACHE_CLEAR("%0", "r7", "%3")
+               "lock   %0, @%3;                                \n\t"
+               "add    %0, %1;                                 \n\t"
+               "unlock %0, @%3;                                \n\t"
+               "mvtc   %2, psw;                                \n\t"
+               ".fillinsn                                      \n"
+               "3:                                             \n\t"
+               "ld     %0, @%3;                                \n\t"
+               "beq    %0, %1, 1b;                             \n\t"
+               "bra    3b;                                     \n\t"
+               LOCK_SECTION_END
+               : "=&r" (tmp0), "=&r" (tmp1), "=&r" (tmp2)
+               : "r" (&rw->lock)
+               : "memory"
+#ifdef CONFIG_CHIP_M32700_TS1
+               , "r7"
+#endif /* CONFIG_CHIP_M32700_TS1 */
+       );
+}
+
+static inline void __raw_read_unlock(raw_rwlock_t *rw)
+{
+       unsigned long tmp0, tmp1;
+
+       __asm__ __volatile__ (
+               "# read_unlock                  \n\t"
+               "mvfc   %1, psw;                \n\t"
+               "clrpsw #0x40 -> nop;           \n\t"
+               DCACHE_CLEAR("%0", "r6", "%2")
+               "lock   %0, @%2;                \n\t"
+               "addi   %0, #1;                 \n\t"
+               "unlock %0, @%2;                \n\t"
+               "mvtc   %1, psw;                \n\t"
+               : "=&r" (tmp0), "=&r" (tmp1)
+               : "r" (&rw->lock)
+               : "memory"
+#ifdef CONFIG_CHIP_M32700_TS1
+               , "r6"
+#endif /* CONFIG_CHIP_M32700_TS1 */
+       );
+}
+
+static inline void __raw_write_unlock(raw_rwlock_t *rw)
+{
+       unsigned long tmp0, tmp1, tmp2;
+
+       __asm__ __volatile__ (
+               "# write_unlock                                 \n\t"
+               "seth   %1, #high(" RW_LOCK_BIAS_STR ");        \n\t"
+               "or3    %1, %1, #low(" RW_LOCK_BIAS_STR ");     \n\t"
+               "mvfc   %2, psw;                                \n\t"
+               "clrpsw #0x40 -> nop;                           \n\t"
+               DCACHE_CLEAR("%0", "r7", "%3")
+               "lock   %0, @%3;                                \n\t"
+               "add    %0, %1;                                 \n\t"
+               "unlock %0, @%3;                                \n\t"
+               "mvtc   %2, psw;                                \n\t"
+               : "=&r" (tmp0), "=&r" (tmp1), "=&r" (tmp2)
+               : "r" (&rw->lock)
+               : "memory"
+#ifdef CONFIG_CHIP_M32700_TS1
+               , "r7"
+#endif /* CONFIG_CHIP_M32700_TS1 */
+       );
+}
+
+static inline int __raw_read_trylock(raw_rwlock_t *lock)
+{
+       atomic_t *count = (atomic_t*)lock;
+       if (atomic_dec_return(count) >= 0)
+               return 1;
+       atomic_inc(count);
+       return 0;
+}
+
+static inline int __raw_write_trylock(raw_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 _raw_spin_relax(lock)  cpu_relax()
+#define _raw_read_relax(lock)  cpu_relax()
+#define _raw_write_relax(lock) cpu_relax()
+
+#endif /* _ASM_M32R_SPINLOCK_H */