https://github.com/torvalds/linux
Revision 98873f53becea9a8a46972ff252e96fe575b120d authored by Ralf Baechle on 09 December 2008, 17:58:46 UTC, committed by Ralf Baechle on 09 December 2008, 21:55:43 UTC
Certain X11 servers such as the SIS server will only work if PCI mmap is
implemented.  This patch implements PCI mmap but to be on the same side
so close to a release it only supports uncached mappings so performance
will not be optimal for some uses such as framebuffers.

Thanks to Zhang Le <r0bertz@gentoo.org> for the original report and
testing.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
1 parent bbeba4c
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Tip revision: 98873f53becea9a8a46972ff252e96fe575b120d authored by Ralf Baechle on 09 December 2008, 17:58:46 UTC
MIPS: Better than nothing implementation of PCI mmap to fix X.
Tip revision: 98873f5
ahash.c
/*
 * Asynchronous Cryptographic Hash operations.
 *
 * This is the asynchronous version of hash.c with notification of
 * completion via a callback.
 *
 * Copyright (c) 2008 Loc Ho <lho@amcc.com>
 *
 * 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 <crypto/internal/hash.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/seq_file.h>

#include "internal.h"

static int hash_walk_next(struct crypto_hash_walk *walk)
{
	unsigned int alignmask = walk->alignmask;
	unsigned int offset = walk->offset;
	unsigned int nbytes = min(walk->entrylen,
				  ((unsigned int)(PAGE_SIZE)) - offset);

	walk->data = crypto_kmap(walk->pg, 0);
	walk->data += offset;

	if (offset & alignmask)
		nbytes = alignmask + 1 - (offset & alignmask);

	walk->entrylen -= nbytes;
	return nbytes;
}

static int hash_walk_new_entry(struct crypto_hash_walk *walk)
{
	struct scatterlist *sg;

	sg = walk->sg;
	walk->pg = sg_page(sg);
	walk->offset = sg->offset;
	walk->entrylen = sg->length;

	if (walk->entrylen > walk->total)
		walk->entrylen = walk->total;
	walk->total -= walk->entrylen;

	return hash_walk_next(walk);
}

int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
{
	unsigned int alignmask = walk->alignmask;
	unsigned int nbytes = walk->entrylen;

	walk->data -= walk->offset;

	if (nbytes && walk->offset & alignmask && !err) {
		walk->offset += alignmask - 1;
		walk->offset = ALIGN(walk->offset, alignmask + 1);
		walk->data += walk->offset;

		nbytes = min(nbytes,
			     ((unsigned int)(PAGE_SIZE)) - walk->offset);
		walk->entrylen -= nbytes;

		return nbytes;
	}

	crypto_kunmap(walk->data, 0);
	crypto_yield(walk->flags);

	if (err)
		return err;

	walk->offset = 0;

	if (nbytes)
		return hash_walk_next(walk);

	if (!walk->total)
		return 0;

	walk->sg = scatterwalk_sg_next(walk->sg);

	return hash_walk_new_entry(walk);
}
EXPORT_SYMBOL_GPL(crypto_hash_walk_done);

int crypto_hash_walk_first(struct ahash_request *req,
			   struct crypto_hash_walk *walk)
{
	walk->total = req->nbytes;

	if (!walk->total)
		return 0;

	walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
	walk->sg = req->src;
	walk->flags = req->base.flags;

	return hash_walk_new_entry(walk);
}
EXPORT_SYMBOL_GPL(crypto_hash_walk_first);

static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
				unsigned int keylen)
{
	struct ahash_alg *ahash = crypto_ahash_alg(tfm);
	unsigned long alignmask = crypto_ahash_alignmask(tfm);
	int ret;
	u8 *buffer, *alignbuffer;
	unsigned long absize;

	absize = keylen + alignmask;
	buffer = kmalloc(absize, GFP_ATOMIC);
	if (!buffer)
		return -ENOMEM;

	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
	memcpy(alignbuffer, key, keylen);
	ret = ahash->setkey(tfm, alignbuffer, keylen);
	memset(alignbuffer, 0, keylen);
	kfree(buffer);
	return ret;
}

static int ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
			unsigned int keylen)
{
	struct ahash_alg *ahash = crypto_ahash_alg(tfm);
	unsigned long alignmask = crypto_ahash_alignmask(tfm);

	if ((unsigned long)key & alignmask)
		return ahash_setkey_unaligned(tfm, key, keylen);

	return ahash->setkey(tfm, key, keylen);
}

static unsigned int crypto_ahash_ctxsize(struct crypto_alg *alg, u32 type,
					u32 mask)
{
	return alg->cra_ctxsize;
}

static int crypto_init_ahash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
	struct ahash_alg *alg = &tfm->__crt_alg->cra_ahash;
	struct ahash_tfm *crt   = &tfm->crt_ahash;

	if (alg->digestsize > PAGE_SIZE / 8)
		return -EINVAL;

	crt->init = alg->init;
	crt->update = alg->update;
	crt->final  = alg->final;
	crt->digest = alg->digest;
	crt->setkey = ahash_setkey;
	crt->digestsize = alg->digestsize;

	return 0;
}

static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
	__attribute__ ((unused));
static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
{
	seq_printf(m, "type         : ahash\n");
	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
					     "yes" : "no");
	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
	seq_printf(m, "digestsize   : %u\n", alg->cra_hash.digestsize);
}

const struct crypto_type crypto_ahash_type = {
	.ctxsize = crypto_ahash_ctxsize,
	.init = crypto_init_ahash_ops,
#ifdef CONFIG_PROC_FS
	.show = crypto_ahash_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_ahash_type);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
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