lkml.org 
[lkml]   [2010]   [Aug]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 16/19] Add helpers for zero-copy userspace access
Date
---
crypto/userspace/cryptodev_main.c | 87 +++++++++++++++++++++++++++++++++++++
1 files changed, 87 insertions(+), 0 deletions(-)

diff --git a/crypto/userspace/cryptodev_main.c b/crypto/userspace/cryptodev_main.c
index c6419f4..a6712db 100644
--- a/crypto/userspace/cryptodev_main.c
+++ b/crypto/userspace/cryptodev_main.c
@@ -1,3 +1,46 @@
+/*
+ * Driver for /dev/crypto device (aka CryptoDev)
+ *
+ * Copyright (c) 2004 Michal Ludvig <mludvig@logix.net.nz>, SuSE Labs
+ * Copyright (c) 2009,2010 Nikos Mavrogiannopoulos <nmav@gnutls.org>
+ *
+ * This file is part of linux cryptodev.
+ *
+ * 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; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/*
+ * Device /dev/crypto provides an interface for
+ * accessing kernel CryptoAPI algorithms (ciphers,
+ * hashes) from userspace programs.
+ *
+ * /dev/crypto interface was originally introduced in
+ * OpenBSD and this module attempts to keep the API.
+ *
+ */
+
+#include <linux/audit.h>
+#include <linux/crypto.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/ioctl.h>
+#include <linux/random.h>
+#include <linux/syscalls.h>
+#include <linux/pagemap.h>
+#include <linux/uaccess.h>
+#include <linux/scatterlist.h>
#include "cryptodev_int.h"
#include "ncr-int.h"
#include <linux/version.h>
@@ -11,3 +54,47 @@ MODULE_LICENSE("GPL");
int cryptodev_verbosity = 0;
module_param(cryptodev_verbosity, int, 0644);
MODULE_PARM_DESC(cryptodev_verbosity, "0: normal, 1: verbose, 2: debug");
+
+/* ====== CryptoAPI ====== */
+
+void release_user_pages(struct page **pg, int pagecount)
+{
+ while (pagecount--) {
+ if (!PageReserved(pg[pagecount]))
+ SetPageDirty(pg[pagecount]);
+ page_cache_release(pg[pagecount]);
+ }
+}
+
+/* offset of buf in it's first page */
+#define PAGEOFFSET(buf) ((unsigned long)buf & ~PAGE_MASK)
+
+/* fetch the pages addr resides in into pg and initialise sg with them */
+int __get_userbuf(uint8_t __user *addr, uint32_t len, int write,
+ int pgcount, struct page **pg, struct scatterlist *sg)
+{
+ int ret, pglen, i = 0;
+ struct scatterlist *sgp;
+
+ down_write(&current->mm->mmap_sem);
+ ret = get_user_pages(current, current->mm,
+ (unsigned long)addr, pgcount, write, 0, pg, NULL);
+ up_write(&current->mm->mmap_sem);
+ if (ret != pgcount)
+ return -EINVAL;
+
+ sg_init_table(sg, pgcount);
+
+ pglen = min((ptrdiff_t)(PAGE_SIZE - PAGEOFFSET(addr)), (ptrdiff_t)len);
+ sg_set_page(sg, pg[i++], pglen, PAGEOFFSET(addr));
+
+ len -= pglen;
+ for (sgp = sg_next(sg); len; sgp = sg_next(sgp)) {
+ pglen = min((uint32_t)PAGE_SIZE, len);
+ sg_set_page(sgp, pg[i++], pglen, 0);
+ len -= pglen;
+ }
+ sg_mark_end(sg_last(sg, pgcount));
+ return 0;
+}
+
--
1.7.2.1


\
 
 \ /
  Last update: 2010-08-20 10:51    [W:0.294 / U:0.236 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site