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-rw-r--r--sys/dev/hwt/hwt_ownerhash.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/sys/dev/hwt/hwt_ownerhash.c b/sys/dev/hwt/hwt_ownerhash.c
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index 000000000000..7c9e2232bac4
--- /dev/null
+++ b/sys/dev/hwt/hwt_ownerhash.c
@@ -0,0 +1,141 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2023-2025 Ruslan Bukin <br@bsdpad.com>
+ *
+ * This work was supported by Innovate UK project 105694, "Digital Security
+ * by Design (DSbD) Technology Platform Prototype".
+ *
+ * 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 THE 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 THE 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.
+ */
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/mman.h>
+#include <sys/mutex.h>
+#include <sys/rwlock.h>
+#include <sys/hwt.h>
+
+#include <dev/hwt/hwt_owner.h>
+#include <dev/hwt/hwt_ownerhash.h>
+
+#define HWT_DEBUG
+#undef HWT_DEBUG
+
+#ifdef HWT_DEBUG
+#define dprintf(fmt, ...) printf(fmt, ##__VA_ARGS__)
+#else
+#define dprintf(fmt, ...)
+#endif
+
+#define HWT_OWNERHASH_SIZE 1024
+
+static MALLOC_DEFINE(M_HWT_OWNERHASH, "hwt_ohash", "Hardware Trace");
+
+/*
+ * Hash function. Discard the lower 2 bits of the pointer since
+ * these are always zero for our uses. The hash multiplier is
+ * round((2^LONG_BIT) * ((sqrt(5)-1)/2)).
+ */
+
+#define _HWT_HM 11400714819323198486u /* hash multiplier */
+#define HWT_HASH_PTR(P, M) ((((unsigned long) (P) >> 2) * _HWT_HM) & (M))
+
+static struct mtx hwt_ownerhash_mtx;
+static u_long hwt_ownerhashmask;
+static LIST_HEAD(hwt_ownerhash, hwt_owner) *hwt_ownerhash;
+
+struct hwt_owner *
+hwt_ownerhash_lookup(struct proc *p)
+{
+ struct hwt_ownerhash *hoh;
+ struct hwt_owner *ho;
+ int hindex;
+
+ hindex = HWT_HASH_PTR(p, hwt_ownerhashmask);
+ hoh = &hwt_ownerhash[hindex];
+
+ HWT_OWNERHASH_LOCK();
+ LIST_FOREACH(ho, hoh, next) {
+ if (ho->p == p) {
+ HWT_OWNERHASH_UNLOCK();
+ return (ho);
+ }
+ }
+ HWT_OWNERHASH_UNLOCK();
+
+ return (NULL);
+}
+
+void
+hwt_ownerhash_insert(struct hwt_owner *ho)
+{
+ struct hwt_ownerhash *hoh;
+ int hindex;
+
+ hindex = HWT_HASH_PTR(ho->p, hwt_ownerhashmask);
+ hoh = &hwt_ownerhash[hindex];
+
+ HWT_OWNERHASH_LOCK();
+ LIST_INSERT_HEAD(hoh, ho, next);
+ HWT_OWNERHASH_UNLOCK();
+}
+
+void
+hwt_ownerhash_remove(struct hwt_owner *ho)
+{
+
+ /* Destroy hwt owner. */
+ HWT_OWNERHASH_LOCK();
+ LIST_REMOVE(ho, next);
+ HWT_OWNERHASH_UNLOCK();
+}
+
+void
+hwt_ownerhash_load(void)
+{
+
+ hwt_ownerhash = hashinit(HWT_OWNERHASH_SIZE, M_HWT_OWNERHASH,
+ &hwt_ownerhashmask);
+ mtx_init(&hwt_ownerhash_mtx, "hwt-owner-hash", "hwt-owner", MTX_DEF);
+}
+
+void
+hwt_ownerhash_unload(void)
+{
+ struct hwt_ownerhash *hoh;
+ struct hwt_owner *ho, *tmp;
+
+ HWT_OWNERHASH_LOCK();
+ for (hoh = hwt_ownerhash;
+ hoh <= &hwt_ownerhash[hwt_ownerhashmask];
+ hoh++) {
+ LIST_FOREACH_SAFE(ho, hoh, next, tmp) {
+ /* TODO: module is in use ? */
+ }
+ }
+ HWT_OWNERHASH_UNLOCK();
+
+ mtx_destroy(&hwt_ownerhash_mtx);
+ hashdestroy(hwt_ownerhash, M_HWT_OWNERHASH, hwt_ownerhashmask);
+}