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authorPaul Mundt <lethal@linux-sh.org>2008-07-29 08:09:44 +0900
committerPaul Mundt <lethal@linux-sh.org>2008-07-29 08:09:44 +0900
commitf15cbe6f1a4b4d9df59142fc8e4abb973302cf44 (patch)
tree774d7b11abaaf33561ab8268bf51ddd9ceb79025 /arch/sh/include/asm/spinlock.h
parent25326277d8d1393d1c66240e6255aca780f9e3eb (diff)
sh: migrate to arch/sh/include/
This follows the sparc changes a439fe51a1f8eb087c22dd24d69cebae4a3addac. Most of the moving about was done with Sam's directions at: http://marc.info/?l=linux-sh&m=121724823706062&w=2 with subsequent hacking and fixups entirely my fault. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/include/asm/spinlock.h')
-rw-r--r--arch/sh/include/asm/spinlock.h223
1 files changed, 223 insertions, 0 deletions
diff --git a/arch/sh/include/asm/spinlock.h b/arch/sh/include/asm/spinlock.h
new file mode 100644
index 00000000000..e793181d64d
--- /dev/null
+++ b/arch/sh/include/asm/spinlock.h
@@ -0,0 +1,223 @@
+/*
+ * include/asm-sh/spinlock.h
+ *
+ * Copyright (C) 2002, 2003 Paul Mundt
+ * Copyright (C) 2006, 2007 Akio Idehara
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#ifndef __ASM_SH_SPINLOCK_H
+#define __ASM_SH_SPINLOCK_H
+
+/*
+ * The only locking implemented here uses SH-4A opcodes. For others,
+ * split this out as per atomic-*.h.
+ */
+#ifndef CONFIG_CPU_SH4A
+#error "Need movli.l/movco.l for spinlocks"
+#endif
+
+/*
+ * Your basic SMP spinlocks, allowing only a single CPU anywhere
+ */
+
+#define __raw_spin_is_locked(x) ((x)->lock <= 0)
+#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
+#define __raw_spin_unlock_wait(x) \
+ do { cpu_relax(); } while ((x)->lock)
+
+/*
+ * 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.
+ */
+static inline void __raw_spin_lock(raw_spinlock_t *lock)
+{
+ unsigned long tmp;
+ unsigned long oldval;
+
+ __asm__ __volatile__ (
+ "1: \n\t"
+ "movli.l @%2, %0 ! __raw_spin_lock \n\t"
+ "mov %0, %1 \n\t"
+ "mov #0, %0 \n\t"
+ "movco.l %0, @%2 \n\t"
+ "bf 1b \n\t"
+ "cmp/pl %1 \n\t"
+ "bf 1b \n\t"
+ : "=&z" (tmp), "=&r" (oldval)
+ : "r" (&lock->lock)
+ : "t", "memory"
+ );
+}
+
+static inline void __raw_spin_unlock(raw_spinlock_t *lock)
+{
+ unsigned long tmp;
+
+ __asm__ __volatile__ (
+ "mov #1, %0 ! __raw_spin_unlock \n\t"
+ "mov.l %0, @%1 \n\t"
+ : "=&z" (tmp)
+ : "r" (&lock->lock)
+ : "t", "memory"
+ );
+}
+
+static inline int __raw_spin_trylock(raw_spinlock_t *lock)
+{
+ unsigned long tmp, oldval;
+
+ __asm__ __volatile__ (
+ "1: \n\t"
+ "movli.l @%2, %0 ! __raw_spin_trylock \n\t"
+ "mov %0, %1 \n\t"
+ "mov #0, %0 \n\t"
+ "movco.l %0, @%2 \n\t"
+ "bf 1b \n\t"
+ "synco \n\t"
+ : "=&z" (tmp), "=&r" (oldval)
+ : "r" (&lock->lock)
+ : "t", "memory"
+ );
+
+ return oldval;
+}
+
+/*
+ * 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 __raw_read_can_lock(x) ((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 tmp;
+
+ __asm__ __volatile__ (
+ "1: \n\t"
+ "movli.l @%1, %0 ! __raw_read_lock \n\t"
+ "cmp/pl %0 \n\t"
+ "bf 1b \n\t"
+ "add #-1, %0 \n\t"
+ "movco.l %0, @%1 \n\t"
+ "bf 1b \n\t"
+ : "=&z" (tmp)
+ : "r" (&rw->lock)
+ : "t", "memory"
+ );
+}
+
+static inline void __raw_read_unlock(raw_rwlock_t *rw)
+{
+ unsigned long tmp;
+
+ __asm__ __volatile__ (
+ "1: \n\t"
+ "movli.l @%1, %0 ! __raw_read_unlock \n\t"
+ "add #1, %0 \n\t"
+ "movco.l %0, @%1 \n\t"
+ "bf 1b \n\t"
+ : "=&z" (tmp)
+ : "r" (&rw->lock)
+ : "t", "memory"
+ );
+}
+
+static inline void __raw_write_lock(raw_rwlock_t *rw)
+{
+ unsigned long tmp;
+
+ __asm__ __volatile__ (
+ "1: \n\t"
+ "movli.l @%1, %0 ! __raw_write_lock \n\t"
+ "cmp/hs %2, %0 \n\t"
+ "bf 1b \n\t"
+ "sub %2, %0 \n\t"
+ "movco.l %0, @%1 \n\t"
+ "bf 1b \n\t"
+ : "=&z" (tmp)
+ : "r" (&rw->lock), "r" (RW_LOCK_BIAS)
+ : "t", "memory"
+ );
+}
+
+static inline void __raw_write_unlock(raw_rwlock_t *rw)
+{
+ __asm__ __volatile__ (
+ "mov.l %1, @%0 ! __raw_write_unlock \n\t"
+ :
+ : "r" (&rw->lock), "r" (RW_LOCK_BIAS)
+ : "t", "memory"
+ );
+}
+
+static inline int __raw_read_trylock(raw_rwlock_t *rw)
+{
+ unsigned long tmp, oldval;
+
+ __asm__ __volatile__ (
+ "1: \n\t"
+ "movli.l @%2, %0 ! __raw_read_trylock \n\t"
+ "mov %0, %1 \n\t"
+ "cmp/pl %0 \n\t"
+ "bf 2f \n\t"
+ "add #-1, %0 \n\t"
+ "movco.l %0, @%2 \n\t"
+ "bf 1b \n\t"
+ "2: \n\t"
+ "synco \n\t"
+ : "=&z" (tmp), "=&r" (oldval)
+ : "r" (&rw->lock)
+ : "t", "memory"
+ );
+
+ return (oldval > 0);
+}
+
+static inline int __raw_write_trylock(raw_rwlock_t *rw)
+{
+ unsigned long tmp, oldval;
+
+ __asm__ __volatile__ (
+ "1: \n\t"
+ "movli.l @%2, %0 ! __raw_write_trylock \n\t"
+ "mov %0, %1 \n\t"
+ "cmp/hs %3, %0 \n\t"
+ "bf 2f \n\t"
+ "sub %3, %0 \n\t"
+ "2: \n\t"
+ "movco.l %0, @%2 \n\t"
+ "bf 1b \n\t"
+ "synco \n\t"
+ : "=&z" (tmp), "=&r" (oldval)
+ : "r" (&rw->lock), "r" (RW_LOCK_BIAS)
+ : "t", "memory"
+ );
+
+ return (oldval > (RW_LOCK_BIAS - 1));
+}
+
+#define _raw_spin_relax(lock) cpu_relax()
+#define _raw_read_relax(lock) cpu_relax()
+#define _raw_write_relax(lock) cpu_relax()
+
+#endif /* __ASM_SH_SPINLOCK_H */