This patch add the 842 cryptographic API driver that
submits compression requests to the 842 hardware compression
accelerator driver (nx-compress).
If the hardware accelerator goes offline for any reason
(dynamic disable, migration, etc...), this driver will use LZO
as a software failover for all future compression requests.
For decompression requests, the 842 hardware driver contains
a software implementation of the 842 decompressor to support
the decompression of data that was compressed before the accelerator
went offline.
Signed-off-by: Robert Jennings <rcj@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Seth Jennings <sjenning@xxxxxxxxxxxxxxxxxx>
---
crypto/842.c | 183 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
crypto/Kconfig | 9 +++
crypto/Makefile | 1 +
3 files changed, 193 insertions(+)
create mode 100644 crypto/842.c
diff --git a/crypto/842.c b/crypto/842.c
new file mode 100644
index 0000000..144767d
--- /dev/null
+++ b/crypto/842.c
@@ -0,0 +1,183 @@
+/*
+ * Cryptographic API for the 842 compression algorithm.
+ *
+ * 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright (C) IBM Corporation, 2011
+ *
+ * Authors: Robert Jennings <rcj@xxxxxxxxxxxxxxxxxx>
+ * Seth Jennings <sjenning@xxxxxxxxxxxxxxxxxx>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/crypto.h>
+#include <linux/vmalloc.h>
+#include <linux/nx842.h>
+#include <linux/lzo.h>
+#include <linux/timer.h>
+
+static int nx842_uselzo;
+
+struct nx842_ctx {
+ void *nx842_wmem; /* working memory for 842/lzo */
+};
+
+enum nx842_crypto_type {
+ NX842_CRYPTO_TYPE_842,
+ NX842_CRYPTO_TYPE_LZO
+};
+
+#define NX842_SENTINEL 0xdeadbeef
+
+struct nx842_crypto_header {
+ unsigned int sentinel; /* debug */
+ enum nx842_crypto_type type;
+};
+
+static int nx842_init(struct crypto_tfm *tfm)
+{
+ struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
+ int wmemsize;
+
+ wmemsize = max_t(int, nx842_get_workmem_size(), LZO1X_MEM_COMPRESS);
+ ctx->nx842_wmem = kmalloc(wmemsize, GFP_NOFS);
+ if (!ctx->nx842_wmem)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void nx842_exit(struct crypto_tfm *tfm)
+{
+ struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ kfree(ctx->nx842_wmem);
+}
+
+static void nx842_reset_uselzo(unsigned long data)
+{
+ nx842_uselzo = 0;
+}
+
+static DEFINE_TIMER(failover_timer, nx842_reset_uselzo, 0, 0);
+
+static int nx842_crypto_compress(struct crypto_tfm *tfm, const u8 *src,
+ unsigned int slen, u8 *dst, unsigned int *dlen)
+{
+ struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct nx842_crypto_header *hdr;
+ unsigned int tmp_len = *dlen;
+ size_t lzodlen; /* needed for lzo */
+ int err;
+
+ *dlen = 0;
+ hdr = (struct nx842_crypto_header *)dst;
+ hdr->sentinel = NX842_SENTINEL; /* debug */
+ dst += sizeof(struct nx842_crypto_header);
+ tmp_len -= sizeof(struct nx842_crypto_header);
+ lzodlen = tmp_len;
+
+ if (likely(!nx842_uselzo)) {
+ err = nx842_compress(src, slen, dst, &tmp_len, ctx->nx842_wmem);
+
+ if (likely(!err)) {
+ hdr->type = NX842_CRYPTO_TYPE_842;
+ *dlen = tmp_len + sizeof(struct nx842_crypto_header);
+ return 0;
+ }
+
+ /* hardware failed */
+ nx842_uselzo = 1;
+
+ /* set timer to check for hardware again in 1 second */
+ mod_timer(&failover_timer, jiffies + msecs_to_jiffies(1000));
+ }
+
+ /* no hardware, use lzo */
+ err = lzo1x_1_compress(src, slen, dst, &lzodlen, ctx->nx842_wmem);
+ if (err != LZO_E_OK)
+ return -EINVAL;
+
+ hdr->type = NX842_CRYPTO_TYPE_LZO;
+ *dlen = lzodlen + sizeof(struct nx842_crypto_header);
+ return 0;
+}
+
+static int nx842_crypto_decompress(struct crypto_tfm *tfm, const u8 *src,
+ unsigned int slen, u8 *dst, unsigned int *dlen)
+{
+ struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct nx842_crypto_header *hdr;
+ unsigned int tmp_len = *dlen;
+ size_t lzodlen; /* needed for lzo */
+ int err;
+
+ *dlen = 0;
+ hdr = (struct nx842_crypto_header *)src;
+
+ if (unlikely(hdr->sentinel != NX842_SENTINEL))
+ return -EINVAL;
+
+ src += sizeof(struct nx842_crypto_header);
+ slen -= sizeof(struct nx842_crypto_header);
+
+ if (likely(hdr->type == NX842_CRYPTO_TYPE_842)) {
+ err = nx842_decompress(src, slen, dst, &tmp_len,
+ ctx->nx842_wmem);
+ if (err)
+ return -EINVAL;
+ *dlen = tmp_len;
+ } else if (hdr->type == NX842_CRYPTO_TYPE_LZO) {
+ lzodlen = tmp_len;
+ err = lzo1x_decompress_safe(src, slen, dst, &lzodlen);
+ if (err != LZO_E_OK)
+ return -EINVAL;
+ *dlen = lzodlen;
+ } else
+ return -EINVAL;
+
+ return 0;
+}
+
+static struct crypto_alg alg = {
+ .cra_name = "842",
+ .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
+ .cra_ctxsize = sizeof(struct nx842_ctx),
+ .cra_module = THIS_MODULE,
+ .cra_list = LIST_HEAD_INIT(alg.cra_list),
+ .cra_init = nx842_init,
+ .cra_exit = nx842_exit,
+ .cra_u = { .compress = {
+ .coa_compress = nx842_crypto_compress,
+ .coa_decompress = nx842_crypto_decompress } }
+};
+
+static int __init nx842_mod_init(void)
+{
+ del_timer(&failover_timer);
+ return crypto_register_alg(&alg);
+}
+
+static void __exit nx842_mod_exit(void)
+{
+ crypto_unregister_alg(&alg);
+}
+
+module_init(nx842_mod_init);
+module_exit(nx842_mod_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("842 Compression Algorithm");
diff --git a/crypto/Kconfig b/crypto/Kconfig
index a323805..7876358 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1008,6 +1008,15 @@ config CRYPTO_LZO
help
This is the LZO algorithm.
+config CRYPTO_842
+ tristate "842 compression algorithm"
+ depends on CRYPTO_DEV_NX_COMPRESS
+ # 842 uses lzo if the hardware becomes unavailable
+ select LZO_COMPRESS
+ select LZO_DECOMPRESS
+ help
+ This is the 842 algorithm.
+
comment "Random Number Generation"
config CRYPTO_ANSI_CPRNG
diff --git a/crypto/Makefile b/crypto/Makefile
index 30f33d6..5d5675c 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -82,6 +82,7 @@ obj-$(CONFIG_CRYPTO_MICHAEL_MIC) += michael_mic.o
obj-$(CONFIG_CRYPTO_CRC32C) += crc32c.o
obj-$(CONFIG_CRYPTO_AUTHENC) += authenc.o authencesn.o
obj-$(CONFIG_CRYPTO_LZO) += lzo.o
+obj-$(CONFIG_CRYPTO_842) += 842.o
obj-$(CONFIG_CRYPTO_RNG2) += rng.o
obj-$(CONFIG_CRYPTO_RNG2) += krng.o
obj-$(CONFIG_CRYPTO_ANSI_CPRNG) += ansi_cprng.o
--
1.7.9.5
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