Revision b7363e67b23e04c23c2a99437feefac7292a88bc authored by Sagi Grimberg on 08 March 2017, 20:03:17 UTC, committed by Doug Ledford on 25 March 2017, 02:24:04 UTC
This workqueue is used by our storage target mode ULPs via the new CQ API. Recent observations when working with very high-end flash storage devices reveal that UNBOUND workqueue threads can migrate between cpu cores and even numa nodes (although some numa locality is accounted for). While this attribute can be useful in some workloads, it does not fit in very nicely with the normal run-to-completion model we usually use in our target-mode ULPs and the block-mq irq<->cpu affinity facilities. The whole block-mq concept is that the completion will land on the same cpu where the submission was performed. The fact that our submitter thread is migrating cpus can break this locality. We assume that as a target mode ULP, we will serve multiple initiators/clients and we can spread the load enough without having to use unbound kworkers. Also, while we're at it, expose this workqueue via sysfs which is harmless and can be useful for debug. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>-- Signed-off-by: Doug Ledford <dledford@redhat.com>
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arc4.c
/*
* Cryptographic API
*
* ARC4 Cipher Algorithm
*
* Jon Oberheide <jon@oberheide.org>
*
* 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.
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/crypto.h>
#include <crypto/algapi.h>
#define ARC4_MIN_KEY_SIZE 1
#define ARC4_MAX_KEY_SIZE 256
#define ARC4_BLOCK_SIZE 1
struct arc4_ctx {
u32 S[256];
u32 x, y;
};
static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct arc4_ctx *ctx = crypto_tfm_ctx(tfm);
int i, j = 0, k = 0;
ctx->x = 1;
ctx->y = 0;
for (i = 0; i < 256; i++)
ctx->S[i] = i;
for (i = 0; i < 256; i++) {
u32 a = ctx->S[i];
j = (j + in_key[k] + a) & 0xff;
ctx->S[i] = ctx->S[j];
ctx->S[j] = a;
if (++k >= key_len)
k = 0;
}
return 0;
}
static void arc4_crypt(struct arc4_ctx *ctx, u8 *out, const u8 *in,
unsigned int len)
{
u32 *const S = ctx->S;
u32 x, y, a, b;
u32 ty, ta, tb;
if (len == 0)
return;
x = ctx->x;
y = ctx->y;
a = S[x];
y = (y + a) & 0xff;
b = S[y];
do {
S[y] = a;
a = (a + b) & 0xff;
S[x] = b;
x = (x + 1) & 0xff;
ta = S[x];
ty = (y + ta) & 0xff;
tb = S[ty];
*out++ = *in++ ^ S[a];
if (--len == 0)
break;
y = ty;
a = ta;
b = tb;
} while (true);
ctx->x = x;
ctx->y = y;
}
static void arc4_crypt_one(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
arc4_crypt(crypto_tfm_ctx(tfm), out, in, 1);
}
static int ecb_arc4_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
struct arc4_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
while (walk.nbytes > 0) {
u8 *wsrc = walk.src.virt.addr;
u8 *wdst = walk.dst.virt.addr;
arc4_crypt(ctx, wdst, wsrc, walk.nbytes);
err = blkcipher_walk_done(desc, &walk, 0);
}
return err;
}
static struct crypto_alg arc4_algs[2] = { {
.cra_name = "arc4",
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = ARC4_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct arc4_ctx),
.cra_module = THIS_MODULE,
.cra_u = {
.cipher = {
.cia_min_keysize = ARC4_MIN_KEY_SIZE,
.cia_max_keysize = ARC4_MAX_KEY_SIZE,
.cia_setkey = arc4_set_key,
.cia_encrypt = arc4_crypt_one,
.cia_decrypt = arc4_crypt_one,
},
},
}, {
.cra_name = "ecb(arc4)",
.cra_priority = 100,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
.cra_blocksize = ARC4_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct arc4_ctx),
.cra_alignmask = 0,
.cra_type = &crypto_blkcipher_type,
.cra_module = THIS_MODULE,
.cra_u = {
.blkcipher = {
.min_keysize = ARC4_MIN_KEY_SIZE,
.max_keysize = ARC4_MAX_KEY_SIZE,
.setkey = arc4_set_key,
.encrypt = ecb_arc4_crypt,
.decrypt = ecb_arc4_crypt,
},
},
} };
static int __init arc4_init(void)
{
return crypto_register_algs(arc4_algs, ARRAY_SIZE(arc4_algs));
}
static void __exit arc4_exit(void)
{
crypto_unregister_algs(arc4_algs, ARRAY_SIZE(arc4_algs));
}
module_init(arc4_init);
module_exit(arc4_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ARC4 Cipher Algorithm");
MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>");
MODULE_ALIAS_CRYPTO("arc4");
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