Move files to match FreeBSD layout

1 files changed, 220 insertions, 0 deletions

diff --git a/freebsd/sys/kern/kern_mtxpool.c b/freebsd/sys/kern/kern_mtxpool.c
new file mode 100644
index 00000000..b2c0267a
--- /dev/null
+++ b/freebsd/sys/kern/kern_mtxpool.c
@@ -0,0 +1,220 @@
+#include <freebsd/machine/rtems-bsd-config.h>
+
+/*-
+ * Copyright (c) 2001 Matthew Dillon.  All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/* Mutex pool routines.  These routines are designed to be used as short
+ * term leaf mutexes (e.g. the last mutex you might acquire other then
+ * calling msleep()).  They operate using a shared pool.  A mutex is chosen
+ * from the pool based on the supplied pointer (which may or may not be
+ * valid).
+ *
+ * Advantages:
+ *	- no structural overhead.  Mutexes can be associated with structures
+ *	  without adding bloat to the structures.
+ *	- mutexes can be obtained for invalid pointers, useful when uses
+ *	  mutexes to interlock destructor ops.
+ *	- no initialization/destructor overhead.
+ *	- can be used with msleep.
+ *
+ * Disadvantages:
+ *	- should generally only be used as leaf mutexes.
+ *	- pool/pool dependancy ordering cannot be depended on.
+ *	- possible L1 cache mastersip contention between cpus.
+ */
+
+#include <freebsd/sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <freebsd/sys/param.h>
+#include <freebsd/sys/proc.h>
+#include <freebsd/sys/kernel.h>
+#include <freebsd/sys/ktr.h>
+#include <freebsd/sys/lock.h>
+#include <freebsd/sys/malloc.h>
+#include <freebsd/sys/mutex.h>
+#include <freebsd/sys/systm.h>
+
+
+static MALLOC_DEFINE(M_MTXPOOL, "mtx_pool", "mutex pool");
+
+/* Pool sizes must be a power of two */
+#ifndef MTX_POOL_LOCKBUILDER_SIZE
+#define MTX_POOL_LOCKBUILDER_SIZE	128
+#endif
+#ifndef MTX_POOL_SLEEP_SIZE
+#define MTX_POOL_SLEEP_SIZE		128
+#endif
+
+struct mtxpool_header {
+	int		mtxpool_size;
+	int		mtxpool_mask;
+	int		mtxpool_shift;
+	int		mtxpool_next;
+};
+
+struct mtx_pool {
+	struct mtxpool_header mtx_pool_header;
+	struct mtx	mtx_pool_ary[1];
+};
+
+static struct mtx_pool_lockbuilder {
+	struct mtxpool_header mtx_pool_header;
+	struct mtx	mtx_pool_ary[MTX_POOL_LOCKBUILDER_SIZE];
+} lockbuilder_pool;
+
+#define mtx_pool_size	mtx_pool_header.mtxpool_size
+#define mtx_pool_mask	mtx_pool_header.mtxpool_mask
+#define mtx_pool_shift	mtx_pool_header.mtxpool_shift
+#define mtx_pool_next	mtx_pool_header.mtxpool_next
+
+struct mtx_pool *mtxpool_sleep;
+struct mtx_pool *mtxpool_lockbuilder;
+
+#if UINTPTR_MAX == UINT64_MAX	/* 64 bits */
+# define POINTER_BITS		64
+# define HASH_MULTIPLIER	11400714819323198485u /* (2^64)*(sqrt(5)-1)/2 */
+#else				/* assume 32 bits */
+# define POINTER_BITS		32
+# define HASH_MULTIPLIER	2654435769u	      /* (2^32)*(sqrt(5)-1)/2 */
+#endif
+
+/*
+ * Return the (shared) pool mutex associated with the specified address.
+ * The returned mutex is a leaf level mutex, meaning that if you obtain it
+ * you cannot obtain any other mutexes until you release it.  You can
+ * legally msleep() on the mutex.
+ */
+struct mtx *
+mtx_pool_find(struct mtx_pool *pool, void *ptr)
+{
+	int p;
+
+	KASSERT(pool != NULL, ("_mtx_pool_find(): null pool"));
+	/*
+	 * Fibonacci hash, see Knuth's
+	 * _Art of Computer Programming, Volume 3 / Sorting and Searching_
+	 */
+	p = ((HASH_MULTIPLIER * (uintptr_t)ptr) >> pool->mtx_pool_shift) &
+	    pool->mtx_pool_mask;
+	return (&pool->mtx_pool_ary[p]);
+}
+
+static void
+mtx_pool_initialize(struct mtx_pool *pool, const char *mtx_name, int pool_size,
+    int opts)
+{
+	int i, maskbits;
+
+	pool->mtx_pool_size = pool_size;
+	pool->mtx_pool_mask = pool_size - 1;
+	for (i = 1, maskbits = 0; (i & pool_size) == 0; i = i << 1)
+		maskbits++;
+	pool->mtx_pool_shift = POINTER_BITS - maskbits;
+	pool->mtx_pool_next = 0;
+	for (i = 0; i < pool_size; ++i)
+		mtx_init(&pool->mtx_pool_ary[i], mtx_name, NULL, opts);
+}
+
+struct mtx_pool *
+mtx_pool_create(const char *mtx_name, int pool_size, int opts)
+{
+	struct mtx_pool *pool;
+
+	if (pool_size <= 0 || !powerof2(pool_size)) {
+		printf("WARNING: %s pool size is not a power of 2.\n",
+		    mtx_name);
+		pool_size = 128;
+	}
+	pool = malloc(sizeof (struct mtx_pool) +
+	    ((pool_size - 1) * sizeof (struct mtx)),
+	    M_MTXPOOL, M_WAITOK | M_ZERO);
+	mtx_pool_initialize(pool, mtx_name, pool_size, opts);
+	return pool;
+}
+
+void
+mtx_pool_destroy(struct mtx_pool **poolp)
+{
+	int i;
+	struct mtx_pool *pool = *poolp;
+
+	for (i = pool->mtx_pool_size - 1; i >= 0; --i)
+		mtx_destroy(&pool->mtx_pool_ary[i]);
+	free(pool, M_MTXPOOL);
+	*poolp = NULL;
+}
+
+static void
+mtx_pool_setup_static(void *dummy __unused)
+{
+	mtx_pool_initialize((struct mtx_pool *)&lockbuilder_pool,
+	    "lockbuilder mtxpool", MTX_POOL_LOCKBUILDER_SIZE,
+	    MTX_DEF | MTX_NOWITNESS | MTX_QUIET);
+	mtxpool_lockbuilder = (struct mtx_pool *)&lockbuilder_pool;
+}
+
+static void
+mtx_pool_setup_dynamic(void *dummy __unused)
+{
+	mtxpool_sleep = mtx_pool_create("sleep mtxpool",
+	    MTX_POOL_SLEEP_SIZE, MTX_DEF);
+}
+
+/*
+ * Obtain a (shared) mutex from the pool.  The returned mutex is a leaf
+ * level mutex, meaning that if you obtain it you cannot obtain any other
+ * mutexes until you release it.  You can legally msleep() on the mutex.
+ */
+struct mtx *
+mtx_pool_alloc(struct mtx_pool *pool)
+{
+	int i;
+
+	KASSERT(pool != NULL, ("mtx_pool_alloc(): null pool"));
+	/*
+	 * mtx_pool_next is unprotected against multiple accesses,
+	 * but simultaneous access by two CPUs should not be very
+	 * harmful.
+	 */
+	i = pool->mtx_pool_next;
+	pool->mtx_pool_next = (i + 1) & pool->mtx_pool_mask;
+	return (&pool->mtx_pool_ary[i]);
+}
+
+/*
+ * The lockbuilder pool must be initialized early because the lockmgr
+ * and sx locks depend on it.  The sx locks are used in the kernel
+ * memory allocator.  The lockmgr subsystem is initialized by
+ * SYSINIT(..., SI_SUB_LOCKMGR, ...).
+ *
+ * We can't call malloc() to dynamically allocate the sleep pool
+ * until after kmeminit() has been called, which is done by
+ * SYSINIT(..., SI_SUB_KMEM, ...).
+ */
+SYSINIT(mtxpooli1, SI_SUB_MTX_POOL_STATIC, SI_ORDER_FIRST,
+    mtx_pool_setup_static, NULL);
+SYSINIT(mtxpooli2, SI_SUB_MTX_POOL_DYNAMIC, SI_ORDER_FIRST,
+    mtx_pool_setup_dynamic, NULL);