1 files changed, 238 insertions, 0 deletions

diff --git a/include/asm-sparc/spinlock.h b/include/asm-sparc/spinlock.h
new file mode 100644
index 000000000000..0cbd87ad4912
--- /dev/null
+++ b/include/asm-sparc/spinlock.h
@@ -0,0 +1,238 @@
+/* spinlock.h: 32-bit Sparc spinlock support.
+ *
+ * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
+ */
+
+#ifndef __SPARC_SPINLOCK_H
+#define __SPARC_SPINLOCK_H
+
+#include <linux/threads.h>      /* For NR_CPUS */
+
+#ifndef __ASSEMBLY__
+
+#include <asm/psr.h>
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+struct _spinlock_debug {
+        unsigned char lock;
+        unsigned long owner_pc;
+#ifdef CONFIG_PREEMPT
+        unsigned int break_lock;
+#endif
+};
+typedef struct _spinlock_debug spinlock_t;
+
+#define SPIN_LOCK_UNLOCKED      (spinlock_t) { 0, 0 }
+#define spin_lock_init(lp)      do { *(lp)= SPIN_LOCK_UNLOCKED; } while(0)
+#define spin_is_locked(lp)  (*((volatile unsigned char *)(&((lp)->lock))) != 0)
+#define spin_unlock_wait(lp)    do { barrier(); } while(*(volatile unsigned char *)(&(lp)->lock))
+
+extern void _do_spin_lock(spinlock_t *lock, char *str);
+extern int _spin_trylock(spinlock_t *lock);
+extern void _do_spin_unlock(spinlock_t *lock);
+
+#define _raw_spin_trylock(lp)   _spin_trylock(lp)
+#define _raw_spin_lock(lock)    _do_spin_lock(lock, "spin_lock")
+#define _raw_spin_unlock(lock)  _do_spin_unlock(lock)
+
+struct _rwlock_debug {
+        volatile unsigned int lock;
+        unsigned long owner_pc;
+        unsigned long reader_pc[NR_CPUS];
+#ifdef CONFIG_PREEMPT
+        unsigned int break_lock;
+#endif
+};
+typedef struct _rwlock_debug rwlock_t;
+
+#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, {0} }
+
+#define rwlock_init(lp) do { *(lp)= RW_LOCK_UNLOCKED; } while(0)
+
+extern void _do_read_lock(rwlock_t *rw, char *str);
+extern void _do_read_unlock(rwlock_t *rw, char *str);
+extern void _do_write_lock(rwlock_t *rw, char *str);
+extern void _do_write_unlock(rwlock_t *rw);
+
+#define _raw_read_lock(lock)    \
+do {    unsigned long flags; \
+        local_irq_save(flags); \
+        _do_read_lock(lock, "read_lock"); \
+        local_irq_restore(flags); \
+} while(0)
+
+#define _raw_read_unlock(lock) \
+do {    unsigned long flags; \
+        local_irq_save(flags); \
+        _do_read_unlock(lock, "read_unlock"); \
+        local_irq_restore(flags); \
+} while(0)
+
+#define _raw_write_lock(lock) \
+do {    unsigned long flags; \
+        local_irq_save(flags); \
+        _do_write_lock(lock, "write_lock"); \
+        local_irq_restore(flags); \
+} while(0)
+
+#define _raw_write_unlock(lock) \
+do {    unsigned long flags; \
+        local_irq_save(flags); \
+        _do_write_unlock(lock); \
+        local_irq_restore(flags); \
+} while(0)
+
+#else /* !CONFIG_DEBUG_SPINLOCK */
+
+typedef struct {
+        unsigned char lock;
+#ifdef CONFIG_PREEMPT
+        unsigned int break_lock;
+#endif
+} spinlock_t;
+
+#define SPIN_LOCK_UNLOCKED      (spinlock_t) { 0 }
+
+#define spin_lock_init(lock)   (*((unsigned char *)(lock)) = 0)
+#define spin_is_locked(lock)    (*((volatile unsigned char *)(lock)) != 0)
+
+#define spin_unlock_wait(lock) \
+do { \
+        barrier(); \
+} while(*((volatile unsigned char *)lock))
+
+extern __inline__ void _raw_spin_lock(spinlock_t *lock)
+{
+        __asm__ __volatile__(
+        "\n1:\n\t"
+        "ldstub [%0], %%g2\n\t"
+        "orcc   %%g2, 0x0, %%g0\n\t"
+        "bne,a  2f\n\t"
+        " ldub  [%0], %%g2\n\t"
+        ".subsection    2\n"
+        "2:\n\t"
+        "orcc   %%g2, 0x0, %%g0\n\t"
+        "bne,a  2b\n\t"
+        " ldub  [%0], %%g2\n\t"
+        "b,a    1b\n\t"
+        ".previous\n"
+        : /* no outputs */
+        : "r" (lock)
+        : "g2", "memory", "cc");
+}
+
+extern __inline__ int _raw_spin_trylock(spinlock_t *lock)
+{
+        unsigned int result;
+        __asm__ __volatile__("ldstub [%1], %0"
+                             : "=r" (result)
+                             : "r" (lock)
+                             : "memory");
+        return (result == 0);
+}
+
+extern __inline__ void _raw_spin_unlock(spinlock_t *lock)
+{
+        __asm__ __volatile__("stb %%g0, [%0]" : : "r" (lock) : "memory");
+}
+
+/* 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.
+ *
+ * XXX This might create some problems with my dual spinlock
+ * XXX scheme, deadlocks etc. -DaveM
+ */
+typedef struct {
+        volatile unsigned int lock;
+#ifdef CONFIG_PREEMPT
+        unsigned int break_lock;
+#endif
+} rwlock_t;
+
+#define RW_LOCK_UNLOCKED (rwlock_t) { 0 }
+
+#define rwlock_init(lp) do { *(lp)= RW_LOCK_UNLOCKED; } while(0)
+
+
+/* Sort of like atomic_t's on Sparc, but even more clever.
+ *
+ *      ------------------------------------
+ *      | 24-bit counter           | wlock |  rwlock_t
+ *      ------------------------------------
+ *       31                       8 7     0
+ *
+ * wlock signifies the one writer is in or somebody is updating
+ * counter. For a writer, if he successfully acquires the wlock,
+ * but counter is non-zero, he has to release the lock and wait,
+ * till both counter and wlock are zero.
+ *
+ * Unfortunately this scheme limits us to ~16,000,000 cpus.
+ */
+extern __inline__ void _read_lock(rwlock_t *rw)
+{
+        register rwlock_t *lp asm("g1");
+        lp = rw;
+        __asm__ __volatile__(
+        "mov    %%o7, %%g4\n\t"
+        "call   ___rw_read_enter\n\t"
+        " ldstub        [%%g1 + 3], %%g2\n"
+        : /* no outputs */
+        : "r" (lp)
+        : "g2", "g4", "memory", "cc");
+}
+
+#define _raw_read_lock(lock) \
+do {    unsigned long flags; \
+        local_irq_save(flags); \
+        _read_lock(lock); \
+        local_irq_restore(flags); \
+} while(0)
+
+extern __inline__ void _read_unlock(rwlock_t *rw)
+{
+        register rwlock_t *lp asm("g1");
+        lp = rw;
+        __asm__ __volatile__(
+        "mov    %%o7, %%g4\n\t"
+        "call   ___rw_read_exit\n\t"
+        " ldstub        [%%g1 + 3], %%g2\n"
+        : /* no outputs */
+        : "r" (lp)
+        : "g2", "g4", "memory", "cc");
+}
+
+#define _raw_read_unlock(lock) \
+do {    unsigned long flags; \
+        local_irq_save(flags); \
+        _read_unlock(lock); \
+        local_irq_restore(flags); \
+} while(0)
+
+extern __inline__ void _raw_write_lock(rwlock_t *rw)
+{
+        register rwlock_t *lp asm("g1");
+        lp = rw;
+        __asm__ __volatile__(
+        "mov    %%o7, %%g4\n\t"
+        "call   ___rw_write_enter\n\t"
+        " ldstub        [%%g1 + 3], %%g2\n"
+        : /* no outputs */
+        : "r" (lp)
+        : "g2", "g4", "memory", "cc");
+}
+
+#define _raw_write_unlock(rw)   do { (rw)->lock = 0; } while(0)
+
+#endif /* CONFIG_DEBUG_SPINLOCK */
+
+#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
+
+#endif /* !(__ASSEMBLY__) */
+
+#endif /* __SPARC_SPINLOCK_H */