[linux-2.6-block.git] / drivers / crypto / omap-crypto.c

/*
 * 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;
#ifdef CONFIG_ZONE_DMA
		if (page_zonenum(sg_page(sg)) != ZONE_DMA)
			return OMAP_CRYPTO_NOT_ALIGNED;
#endif

		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>");
Commit	Line	Data
74ed87e7 TK	1	/*
	2	* OMAP Crypto driver common support routines.
	3	*
	4	* Copyright (c) 2017 Texas Instruments Incorporated
	5	* Tero Kristo <t-kristo@ti.com>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as published
	9	* by the Free Software Foundation.
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/kernel.h>
	14	#include <linux/scatterlist.h>
	15	#include <crypto/scatterwalk.h>
	16
	17	#include "omap-crypto.h"
	18
	19	static int omap_crypto_copy_sg_lists(int total, int bs,
	20	struct scatterlist **sg,
	21	struct scatterlist *new_sg, u16 flags)
	22	{
	23	int n = sg_nents(*sg);
	24	struct scatterlist *tmp;
	25
	26	if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) {
	27	new_sg = kmalloc_array(n, sizeof(*sg), GFP_KERNEL);
	28	if (!new_sg)
	29	return -ENOMEM;
	30
	31	sg_init_table(new_sg, n);
	32	}
	33
	34	tmp = new_sg;
	35
	36	while (*sg && total) {
	37	int len = (*sg)->length;
	38
	39	if (total < len)
	40	len = total;
	41
	42	if (len > 0) {
	43	total -= len;
	44	sg_set_page(tmp, sg_page(sg), len, (sg)->offset);
	45	if (total <= 0)
	46	sg_mark_end(tmp);
	47	tmp = sg_next(tmp);
	48	}
	49
	50	sg = sg_next(sg);
	51	}
	52
	53	*sg = new_sg;
	54
	55	return 0;
	56	}
	57
	58	static int omap_crypto_copy_sgs(int total, int bs, struct scatterlist **sg,
	59	struct scatterlist *new_sg, u16 flags)
	60	{
	61	void *buf;
	62	int pages;
	63	int new_len;
	64
65	new_len = ALIGN(total, bs);
66	pages = get_order(new_len);
67
68	buf = (void *)__get_free_pages(GFP_ATOMIC, pages);
69	if (!buf) {
70	pr_err("%s: Couldn't allocate pages for unaligned cases.\n",
71	__func__);
72	return -ENOMEM;
73	}
74
75	if (flags & OMAP_CRYPTO_COPY_DATA) {
76	scatterwalk_map_and_copy(buf, *sg, 0, total, 0);
77	if (flags & OMAP_CRYPTO_ZERO_BUF)
78	memset(buf + total, 0, new_len - total);
79	}
80
81	if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))
82	sg_init_table(new_sg, 1);
83
84	sg_set_buf(new_sg, buf, new_len);
85
86	*sg = new_sg;
87
88	return 0;
89	}
90
91	static int omap_crypto_check_sg(struct scatterlist *sg, int total, int bs,
92	u16 flags)
93	{
94	int len = 0;
95	int num_sg = 0;
96
97	if (!IS_ALIGNED(total, bs))
98	return OMAP_CRYPTO_NOT_ALIGNED;
99
100	while (sg) {
101	num_sg++;
102
103	if (!IS_ALIGNED(sg->offset, 4))
104	return OMAP_CRYPTO_NOT_ALIGNED;
105	if (!IS_ALIGNED(sg->length, bs))
106	return OMAP_CRYPTO_NOT_ALIGNED;
065fa252 TK	107	#ifdef CONFIG_ZONE_DMA
	108	if (page_zonenum(sg_page(sg)) != ZONE_DMA)
	109	return OMAP_CRYPTO_NOT_ALIGNED;
	110	#endif
74ed87e7 TK	111
	112	len += sg->length;
	113	sg = sg_next(sg);
	114
	115	if (len >= total)
	116	break;
	117	}
	118
	119	if ((flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) && num_sg > 1)
	120	return OMAP_CRYPTO_NOT_ALIGNED;
	121
	122	if (len != total)
	123	return OMAP_CRYPTO_BAD_DATA_LENGTH;
	124
	125	return 0;
	126	}
	127
	128	int omap_crypto_align_sg(struct scatterlist **sg, int total, int bs,
	129	struct scatterlist *new_sg, u16 flags,
	130	u8 flags_shift, unsigned long *dd_flags)
	131	{
	132	int ret;
	133
	134	*dd_flags &= ~(OMAP_CRYPTO_COPY_MASK << flags_shift);
	135
	136	if (flags & OMAP_CRYPTO_FORCE_COPY)
	137	ret = OMAP_CRYPTO_NOT_ALIGNED;
	138	else
	139	ret = omap_crypto_check_sg(*sg, total, bs, flags);
	140
	141	if (ret == OMAP_CRYPTO_NOT_ALIGNED) {
	142	ret = omap_crypto_copy_sgs(total, bs, sg, new_sg, flags);
	143	if (ret)
	144	return ret;
	145	*dd_flags \|= OMAP_CRYPTO_DATA_COPIED << flags_shift;
	146	} else if (ret == OMAP_CRYPTO_BAD_DATA_LENGTH) {
	147	ret = omap_crypto_copy_sg_lists(total, bs, sg, new_sg, flags);
	148	if (ret)
	149	return ret;
	150	if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))
	151	*dd_flags \|= OMAP_CRYPTO_SG_COPIED << flags_shift;
	152	} else if (flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) {
	153	sg_set_buf(new_sg, sg_virt(sg), (sg)->length);
	154	}
	155
	156	return 0;
	157	}
	158	EXPORT_SYMBOL_GPL(omap_crypto_align_sg);
	159
	160	void omap_crypto_cleanup(struct scatterlist sg, struct scatterlist orig,
	161	int offset, int len, u8 flags_shift,
	162	unsigned long flags)
	163	{
	164	void *buf;
	165	int pages;
	166
	167	flags >>= flags_shift;
	168	flags &= OMAP_CRYPTO_COPY_MASK;
	169
	170	if (!flags)
	171	return;
	172
	173	buf = sg_virt(sg);
	174	pages = get_order(len);
175
176	if (orig && (flags & OMAP_CRYPTO_COPY_MASK))
177	scatterwalk_map_and_copy(buf, orig, offset, len, 1);
178
179	if (flags & OMAP_CRYPTO_DATA_COPIED)
180	free_pages((unsigned long)buf, pages);
181	else if (flags & OMAP_CRYPTO_SG_COPIED)
182	kfree(sg);
183	}
184	EXPORT_SYMBOL_GPL(omap_crypto_cleanup);
185
186	MODULE_DESCRIPTION("OMAP crypto support library.");
187	MODULE_LICENSE("GPL v2");
188	MODULE_AUTHOR("Tero Kristo <t-kristo@ti.com>");