arch/tile: core support for Tilera 32-bit chips.

This change is the core kernel support for TILEPro and TILE64 chips.
No driver support (except the console driver) is included yet.

This includes the relevant Linux headers in asm/; the low-level
low-level "Tile architecture" headers in arch/, which are
shared with the hypervisor, etc., and are build-system agnostic;
and the relevant hypervisor headers in hv/.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 353 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..e4f8b4f04895
--- /dev/null
+++ b/arch/tile/include/asm/atomic_32.h
@@ -0,0 +1,353 @@
+/*
+ * 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
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_TILE_ATOMIC_32_H */