diff options
Diffstat (limited to 'sys/dev/hwt/hwt_contexthash.c')
| -rw-r--r-- | sys/dev/hwt/hwt_contexthash.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/sys/dev/hwt/hwt_contexthash.c b/sys/dev/hwt/hwt_contexthash.c new file mode 100644 index 000000000000..5682b7d38e5e --- /dev/null +++ b/sys/dev/hwt/hwt_contexthash.c @@ -0,0 +1,134 @@ +/*- + * 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/lock.h> +#include <sys/malloc.h> +#include <sys/mutex.h> +#include <sys/refcount.h> +#include <sys/hwt.h> + +#include <dev/hwt/hwt_context.h> +#include <dev/hwt/hwt_contexthash.h> +#include <dev/hwt/hwt_config.h> + +#define HWT_DEBUG +#undef HWT_DEBUG + +#ifdef HWT_DEBUG +#define dprintf(fmt, ...) printf(fmt, ##__VA_ARGS__) +#else +#define dprintf(fmt, ...) +#endif + +#define HWT_CONTEXTHASH_SIZE 1024 + +static MALLOC_DEFINE(M_HWT_CONTEXTHASH, "hwt_chash", "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_contexthash_mtx; +static u_long hwt_contexthashmask; +static LIST_HEAD(hwt_contexthash, hwt_context) *hwt_contexthash; + +/* + * To use by hwt_switch_in/out() and hwt_record() only. + * This function returns with refcnt acquired. + */ +struct hwt_context * +hwt_contexthash_lookup(struct proc *p) +{ + struct hwt_contexthash *hch; + struct hwt_context *ctx; + int hindex; + + hindex = HWT_HASH_PTR(p, hwt_contexthashmask); + hch = &hwt_contexthash[hindex]; + + HWT_CTXHASH_LOCK(); + LIST_FOREACH(ctx, hch, next_hch) { + if (ctx->proc == p) { + refcount_acquire(&ctx->refcnt); + HWT_CTXHASH_UNLOCK(); + return (ctx); + } + } + HWT_CTXHASH_UNLOCK(); + + return (NULL); +} + +void +hwt_contexthash_insert(struct hwt_context *ctx) +{ + struct hwt_contexthash *hch; + int hindex; + + hindex = HWT_HASH_PTR(ctx->proc, hwt_contexthashmask); + hch = &hwt_contexthash[hindex]; + + HWT_CTXHASH_LOCK(); + LIST_INSERT_HEAD(hch, ctx, next_hch); + HWT_CTXHASH_UNLOCK(); +} + +void +hwt_contexthash_remove(struct hwt_context *ctx) +{ + + HWT_CTXHASH_LOCK(); + LIST_REMOVE(ctx, next_hch); + HWT_CTXHASH_UNLOCK(); +} + +void +hwt_contexthash_load(void) +{ + + hwt_contexthash = hashinit(HWT_CONTEXTHASH_SIZE, M_HWT_CONTEXTHASH, + &hwt_contexthashmask); + mtx_init(&hwt_contexthash_mtx, "hwt ctx hash", "hwt ctx", MTX_SPIN); +} + +void +hwt_contexthash_unload(void) +{ + + mtx_destroy(&hwt_contexthash_mtx); + hashdestroy(hwt_contexthash, M_HWT_CONTEXTHASH, hwt_contexthashmask); +} |