1 files changed, 370 insertions, 0 deletions

diff --git a/arch/tile/include/asm/atomic_32.h b/arch/tile/include/asm/atomic_32.h
new file mode 100644
index 000000000000..40a5a3a876d9
--- /dev/null
+++ b/arch/tile/include/asm/atomic_32.h
@@ -0,0 +1,370 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * Do not include directly; use <asm/atomic.h>.
+ */
+
+#ifndef _ASM_TILE_ATOMIC_32_H
+#define _ASM_TILE_ATOMIC_32_H
+
+#include <arch/chip.h>
+
+#ifndef __ASSEMBLY__
+
+/* Tile-specific routines to support <asm/atomic.h>. */
+int _atomic_xchg(atomic_t *v, int n);
+int _atomic_xchg_add(atomic_t *v, int i);
+int _atomic_xchg_add_unless(atomic_t *v, int a, int u);
+int _atomic_cmpxchg(atomic_t *v, int o, int n);
+
+/**
+ * atomic_xchg - atomically exchange contents of memory with a new value
+ * @v: pointer of type atomic_t
+ * @i: integer value to store in memory
+ *
+ * Atomically sets @v to @i and returns old @v
+ */
+static inline int atomic_xchg(atomic_t *v, int n)
+{
+        smp_mb();  /* barrier for proper semantics */
+        return _atomic_xchg(v, n);
+}
+
+/**
+ * atomic_cmpxchg - atomically exchange contents of memory if it matches
+ * @v: pointer of type atomic_t
+ * @o: old value that memory should have
+ * @n: new value to write to memory if it matches
+ *
+ * Atomically checks if @v holds @o and replaces it with @n if so.
+ * Returns the old value at @v.
+ */
+static inline int atomic_cmpxchg(atomic_t *v, int o, int n)
+{
+        smp_mb();  /* barrier for proper semantics */
+        return _atomic_cmpxchg(v, o, n);
+}
+
+/**
+ * atomic_add - add integer to atomic variable
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v.
+ */
+static inline void atomic_add(int i, atomic_t *v)
+{
+        _atomic_xchg_add(v, i);
+}
+
+/**
+ * atomic_add_return - add integer and return
+ * @v: pointer of type atomic_t
+ * @i: integer value to add
+ *
+ * Atomically adds @i to @v and returns @i + @v
+ */
+static inline int atomic_add_return(int i, atomic_t *v)
+{
+        smp_mb();  /* barrier for proper semantics */
+        return _atomic_xchg_add(v, i) + i;
+}
+
+/**
+ * atomic_add_unless - add unless the number is already a given value
+ * @v: pointer of type atomic_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as @v was not already @u.
+ * Returns non-zero if @v was not @u, and zero otherwise.
+ */
+static inline int atomic_add_unless(atomic_t *v, int a, int u)
+{
+        smp_mb();  /* barrier for proper semantics */
+        return _atomic_xchg_add_unless(v, a, u) != u;
+}
+
+/**
+ * atomic_set - set atomic variable
+ * @v: pointer of type atomic_t
+ * @i: required value
+ *
+ * Atomically sets the value of @v to @i.
+ *
+ * atomic_set() can't be just a raw store, since it would be lost if it
+ * fell between the load and store of one of the other atomic ops.
+ */
+static inline void atomic_set(atomic_t *v, int n)
+{
+        _atomic_xchg(v, n);
+}
+
+#define xchg(ptr, x) ((typeof(*(ptr))) \
+  ((sizeof(*(ptr)) == sizeof(atomic_t)) ? \
+   atomic_xchg((atomic_t *)(ptr), (long)(x)) : \
+   __xchg_called_with_bad_pointer()))
+
+#define cmpxchg(ptr, o, n) ((typeof(*(ptr))) \
+  ((sizeof(*(ptr)) == sizeof(atomic_t)) ? \
+   atomic_cmpxchg((atomic_t *)(ptr), (long)(o), (long)(n)) : \
+   __cmpxchg_called_with_bad_pointer()))
+
+/* A 64bit atomic type */
+
+typedef struct {
+        u64 __aligned(8) counter;
+} atomic64_t;
+
+#define ATOMIC64_INIT(val) { (val) }
+
+u64 _atomic64_xchg(atomic64_t *v, u64 n);
+u64 _atomic64_xchg_add(atomic64_t *v, u64 i);
+u64 _atomic64_xchg_add_unless(atomic64_t *v, u64 a, u64 u);
+u64 _atomic64_cmpxchg(atomic64_t *v, u64 o, u64 n);
+
+/**
+ * atomic64_read - read atomic variable
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically reads the value of @v.
+ */
+static inline u64 atomic64_read(const atomic64_t *v)
+{
+        /*
+         * Requires an atomic op to read both 32-bit parts consistently.
+         * Casting away const is safe since the atomic support routines
+         * do not write to memory if the value has not been modified.
+         */
+        return _atomic64_xchg_add((atomic64_t *)v, 0);
+}
+
+/**
+ * atomic64_xchg - atomically exchange contents of memory with a new value
+ * @v: pointer of type atomic64_t
+ * @i: integer value to store in memory
+ *
+ * Atomically sets @v to @i and returns old @v
+ */
+static inline u64 atomic64_xchg(atomic64_t *v, u64 n)
+{
+        smp_mb();  /* barrier for proper semantics */
+        return _atomic64_xchg(v, n);
+}
+
+/**
+ * atomic64_cmpxchg - atomically exchange contents of memory if it matches
+ * @v: pointer of type atomic64_t
+ * @o: old value that memory should have
+ * @n: new value to write to memory if it matches
+ *
+ * Atomically checks if @v holds @o and replaces it with @n if so.
+ * Returns the old value at @v.
+ */
+static inline u64 atomic64_cmpxchg(atomic64_t *v, u64 o, u64 n)
+{
+        smp_mb();  /* barrier for proper semantics */
+        return _atomic64_cmpxchg(v, o, n);
+}
+
+/**
+ * atomic64_add - add integer to atomic variable
+ * @i: integer value to add
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically adds @i to @v.
+ */
+static inline void atomic64_add(u64 i, atomic64_t *v)
+{
+        _atomic64_xchg_add(v, i);
+}
+
+/**
+ * atomic64_add_return - add integer and return
+ * @v: pointer of type atomic64_t
+ * @i: integer value to add
+ *
+ * Atomically adds @i to @v and returns @i + @v
+ */
+static inline u64 atomic64_add_return(u64 i, atomic64_t *v)
+{
+        smp_mb();  /* barrier for proper semantics */
+        return _atomic64_xchg_add(v, i) + i;
+}
+
+/**
+ * atomic64_add_unless - add unless the number is already a given value
+ * @v: pointer of type atomic64_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as @v was not already @u.
+ * Returns non-zero if @v was not @u, and zero otherwise.
+ */
+static inline u64 atomic64_add_unless(atomic64_t *v, u64 a, u64 u)
+{
+        smp_mb();  /* barrier for proper semantics */
+        return _atomic64_xchg_add_unless(v, a, u) != u;
+}
+
+/**
+ * atomic64_set - set atomic variable
+ * @v: pointer of type atomic64_t
+ * @i: required value
+ *
+ * Atomically sets the value of @v to @i.
+ *
+ * atomic64_set() can't be just a raw store, since it would be lost if it
+ * fell between the load and store of one of the other atomic ops.
+ */
+static inline void atomic64_set(atomic64_t *v, u64 n)
+{
+        _atomic64_xchg(v, n);
+}
+
+#define atomic64_add_negative(a, v)     (atomic64_add_return((a), (v)) < 0)
+#define atomic64_inc(v)                 atomic64_add(1LL, (v))
+#define atomic64_inc_return(v)          atomic64_add_return(1LL, (v))
+#define atomic64_inc_and_test(v)        (atomic64_inc_return(v) == 0)
+#define atomic64_sub_return(i, v)       atomic64_add_return(-(i), (v))
+#define atomic64_sub_and_test(a, v)     (atomic64_sub_return((a), (v)) == 0)
+#define atomic64_sub(i, v)              atomic64_add(-(i), (v))
+#define atomic64_dec(v)                 atomic64_sub(1LL, (v))
+#define atomic64_dec_return(v)          atomic64_sub_return(1LL, (v))
+#define atomic64_dec_and_test(v)        (atomic64_dec_return((v)) == 0)
+#define atomic64_inc_not_zero(v)        atomic64_add_unless((v), 1LL, 0LL)
+
+/*
+ * We need to barrier before modifying the word, since the _atomic_xxx()
+ * routines just tns the lock and then read/modify/write of the word.
+ * But after the word is updated, the routine issues an "mf" before returning,
+ * and since it's a function call, we don't even need a compiler barrier.
+ */
+#define smp_mb__before_atomic_dec()     smp_mb()
+#define smp_mb__before_atomic_inc()     smp_mb()
+#define smp_mb__after_atomic_dec()      do { } while (0)
+#define smp_mb__after_atomic_inc()      do { } while (0)
+
+
+/*
+ * Support "tns" atomic integers.  These are atomic integers that can
+ * hold any value but "1".  They are more efficient than regular atomic
+ * operations because the "lock" (aka acquire) step is a single "tns"
+ * in the uncontended case, and the "unlock" (aka release) step is a
+ * single "store" without an mf.  (However, note that on tilepro the
+ * "tns" will evict the local cache line, so it's not all upside.)
+ *
+ * Note that you can ONLY observe the value stored in the pointer
+ * using these operations; a direct read of the value may confusingly
+ * return the special value "1".
+ */
+
+int __tns_atomic_acquire(atomic_t *);
+void __tns_atomic_release(atomic_t *p, int v);
+
+static inline void tns_atomic_set(atomic_t *v, int i)
+{
+        __tns_atomic_acquire(v);
+        __tns_atomic_release(v, i);
+}
+
+static inline int tns_atomic_cmpxchg(atomic_t *v, int o, int n)
+{
+        int ret = __tns_atomic_acquire(v);
+        __tns_atomic_release(v, (ret == o) ? n : ret);
+        return ret;
+}
+
+static inline int tns_atomic_xchg(atomic_t *v, int n)
+{
+        int ret = __tns_atomic_acquire(v);
+        __tns_atomic_release(v, n);
+        return ret;
+}
+
+#endif /* !__ASSEMBLY__ */
+
+/*
+ * Internal definitions only beyond this point.
+ */
+
+#define ATOMIC_LOCKS_FOUND_VIA_TABLE() \
+  (!CHIP_HAS_CBOX_HOME_MAP() && defined(CONFIG_SMP))
+
+#if ATOMIC_LOCKS_FOUND_VIA_TABLE()
+
+/* Number of entries in atomic_lock_ptr[]. */
+#define ATOMIC_HASH_L1_SHIFT 6
+#define ATOMIC_HASH_L1_SIZE (1 << ATOMIC_HASH_L1_SHIFT)
+
+/* Number of locks in each struct pointed to by atomic_lock_ptr[]. */
+#define ATOMIC_HASH_L2_SHIFT (CHIP_L2_LOG_LINE_SIZE() - 2)
+#define ATOMIC_HASH_L2_SIZE (1 << ATOMIC_HASH_L2_SHIFT)
+
+#else /* ATOMIC_LOCKS_FOUND_VIA_TABLE() */
+
+/*
+ * Number of atomic locks in atomic_locks[]. Must be a power of two.
+ * There is no reason for more than PAGE_SIZE / 8 entries, since that
+ * is the maximum number of pointer bits we can use to index this.
+ * And we cannot have more than PAGE_SIZE / 4, since this has to
+ * fit on a single page and each entry takes 4 bytes.
+ */
+#define ATOMIC_HASH_SHIFT (PAGE_SHIFT - 3)
+#define ATOMIC_HASH_SIZE (1 << ATOMIC_HASH_SHIFT)
+
+#ifndef __ASSEMBLY__
+extern int atomic_locks[];
+#endif
+
+#endif /* ATOMIC_LOCKS_FOUND_VIA_TABLE() */
+
+/*
+ * All the code that may fault while holding an atomic lock must
+ * place the pointer to the lock in ATOMIC_LOCK_REG so the fault code
+ * can correctly release and reacquire the lock.  Note that we
+ * mention the register number in a comment in "lib/atomic_asm.S" to help
+ * assembly coders from using this register by mistake, so if it
+ * is changed here, change that comment as well.
+ */
+#define ATOMIC_LOCK_REG 20
+#define ATOMIC_LOCK_REG_NAME r20
+
+#ifndef __ASSEMBLY__
+/* Called from setup to initialize a hash table to point to per_cpu locks. */
+void __init_atomic_per_cpu(void);
+
+#ifdef CONFIG_SMP
+/* Support releasing the atomic lock in do_page_fault_ics(). */
+void __atomic_fault_unlock(int *lock_ptr);
+#endif
+
+/* Private helper routines in lib/atomic_asm_32.S */
+extern struct __get_user __atomic_cmpxchg(volatile int *p,
+                                          int *lock, int o, int n);
+extern struct __get_user __atomic_xchg(volatile int *p, int *lock, int n);
+extern struct __get_user __atomic_xchg_add(volatile int *p, int *lock, int n);
+extern struct __get_user __atomic_xchg_add_unless(volatile int *p,
+                                                  int *lock, int o, int n);
+extern struct __get_user __atomic_or(volatile int *p, int *lock, int n);
+extern struct __get_user __atomic_andn(volatile int *p, int *lock, int n);
+extern struct __get_user __atomic_xor(volatile int *p, int *lock, int n);
+extern u64 __atomic64_cmpxchg(volatile u64 *p, int *lock, u64 o, u64 n);
+extern u64 __atomic64_xchg(volatile u64 *p, int *lock, u64 n);
+extern u64 __atomic64_xchg_add(volatile u64 *p, int *lock, u64 n);
+extern u64 __atomic64_xchg_add_unless(volatile u64 *p,
+                                      int *lock, u64 o, u64 n);
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_TILE_ATOMIC_32_H */