linux/drivers/crypto/omap-crypto.c

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/*
* OMAP Crypto driver common support routines.
*
* Copyright (c) 2017 Texas Instruments Incorporated
* Tero Kristo <t-kristo@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/scatterlist.h>
#include <crypto/scatterwalk.h>
#include "omap-crypto.h"
static int omap_crypto_copy_sg_lists(int total, int bs,
struct scatterlist **sg,
struct scatterlist *new_sg, u16 flags)
{
int n = sg_nents(*sg);
struct scatterlist *tmp;
if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) {
new_sg = kmalloc_array(n, sizeof(*sg), GFP_KERNEL);
if (!new_sg)
return -ENOMEM;
sg_init_table(new_sg, n);
}
tmp = new_sg;
while (*sg && total) {
int len = (*sg)->length;
if (total < len)
len = total;
if (len > 0) {
total -= len;
sg_set_page(tmp, sg_page(*sg), len, (*sg)->offset);
if (total <= 0)
sg_mark_end(tmp);
tmp = sg_next(tmp);
}
*sg = sg_next(*sg);
}
*sg = new_sg;
return 0;
}
static int omap_crypto_copy_sgs(int total, int bs, struct scatterlist **sg,
struct scatterlist *new_sg, u16 flags)
{
void *buf;
int pages;
int new_len;
new_len = ALIGN(total, bs);
pages = get_order(new_len);
buf = (void *)__get_free_pages(GFP_ATOMIC, pages);
if (!buf) {
pr_err("%s: Couldn't allocate pages for unaligned cases.\n",
__func__);
return -ENOMEM;
}
if (flags & OMAP_CRYPTO_COPY_DATA) {
scatterwalk_map_and_copy(buf, *sg, 0, total, 0);
if (flags & OMAP_CRYPTO_ZERO_BUF)
memset(buf + total, 0, new_len - total);
}
if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))
sg_init_table(new_sg, 1);
sg_set_buf(new_sg, buf, new_len);
*sg = new_sg;
return 0;
}
static int omap_crypto_check_sg(struct scatterlist *sg, int total, int bs,
u16 flags)
{
int len = 0;
int num_sg = 0;
if (!IS_ALIGNED(total, bs))
return OMAP_CRYPTO_NOT_ALIGNED;
while (sg) {
num_sg++;
if (!IS_ALIGNED(sg->offset, 4))
return OMAP_CRYPTO_NOT_ALIGNED;
if (!IS_ALIGNED(sg->length, bs))
return OMAP_CRYPTO_NOT_ALIGNED;
len += sg->length;
sg = sg_next(sg);
if (len >= total)
break;
}
if ((flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) && num_sg > 1)
return OMAP_CRYPTO_NOT_ALIGNED;
if (len != total)
return OMAP_CRYPTO_BAD_DATA_LENGTH;
return 0;
}
int omap_crypto_align_sg(struct scatterlist **sg, int total, int bs,
struct scatterlist *new_sg, u16 flags,
u8 flags_shift, unsigned long *dd_flags)
{
int ret;
*dd_flags &= ~(OMAP_CRYPTO_COPY_MASK << flags_shift);
if (flags & OMAP_CRYPTO_FORCE_COPY)
ret = OMAP_CRYPTO_NOT_ALIGNED;
else
ret = omap_crypto_check_sg(*sg, total, bs, flags);
if (ret == OMAP_CRYPTO_NOT_ALIGNED) {
ret = omap_crypto_copy_sgs(total, bs, sg, new_sg, flags);
if (ret)
return ret;
*dd_flags |= OMAP_CRYPTO_DATA_COPIED << flags_shift;
} else if (ret == OMAP_CRYPTO_BAD_DATA_LENGTH) {
ret = omap_crypto_copy_sg_lists(total, bs, sg, new_sg, flags);
if (ret)
return ret;
if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))
*dd_flags |= OMAP_CRYPTO_SG_COPIED << flags_shift;
} else if (flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) {
sg_set_buf(new_sg, sg_virt(*sg), (*sg)->length);
}
return 0;
}
EXPORT_SYMBOL_GPL(omap_crypto_align_sg);
void omap_crypto_cleanup(struct scatterlist *sg, struct scatterlist *orig,
int offset, int len, u8 flags_shift,
unsigned long flags)
{
void *buf;
int pages;
flags >>= flags_shift;
flags &= OMAP_CRYPTO_COPY_MASK;
if (!flags)
return;
buf = sg_virt(sg);
pages = get_order(len);
if (orig && (flags & OMAP_CRYPTO_COPY_MASK))
scatterwalk_map_and_copy(buf, orig, offset, len, 1);
if (flags & OMAP_CRYPTO_DATA_COPIED)
free_pages((unsigned long)buf, pages);
else if (flags & OMAP_CRYPTO_SG_COPIED)
kfree(sg);
}
EXPORT_SYMBOL_GPL(omap_crypto_cleanup);
MODULE_DESCRIPTION("OMAP crypto support library.");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Tero Kristo <t-kristo@ti.com>");