linux/drivers/crypto/mv_cesa.c

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/*
* Support for Marvell's crypto engine which can be found on some Orion5X
* boards.
*
* Author: Sebastian Andrzej Siewior < sebastian at breakpoint dot cc >
* License: GPLv2
*
*/
#include <crypto/aes.h>
#include <crypto/algapi.h>
#include <linux/crypto.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kthread.h>
#include <linux/platform_device.h>
#include <linux/scatterlist.h>
#include "mv_cesa.h"
/*
* STM:
* /---------------------------------------\
* | | request complete
* \./ |
* IDLE -> new request -> BUSY -> done -> DEQUEUE
* /°\ |
* | | more scatter entries
* \________________/
*/
enum engine_status {
ENGINE_IDLE,
ENGINE_BUSY,
ENGINE_W_DEQUEUE,
};
/**
* struct req_progress - used for every crypt request
* @src_sg_it: sg iterator for src
* @dst_sg_it: sg iterator for dst
* @sg_src_left: bytes left in src to process (scatter list)
* @src_start: offset to add to src start position (scatter list)
* @crypt_len: length of current crypt process
* @sg_dst_left: bytes left dst to process in this scatter list
* @dst_start: offset to add to dst start position (scatter list)
* @total_req_bytes: total number of bytes processed (request).
*
* sg helper are used to iterate over the scatterlist. Since the size of the
* SRAM may be less than the scatter size, this struct struct is used to keep
* track of progress within current scatterlist.
*/
struct req_progress {
struct sg_mapping_iter src_sg_it;
struct sg_mapping_iter dst_sg_it;
/* src mostly */
int sg_src_left;
int src_start;
int crypt_len;
/* dst mostly */
int sg_dst_left;
int dst_start;
int total_req_bytes;
};
struct crypto_priv {
void __iomem *reg;
void __iomem *sram;
int irq;
struct task_struct *queue_th;
/* the lock protects queue and eng_st */
spinlock_t lock;
struct crypto_queue queue;
enum engine_status eng_st;
struct ablkcipher_request *cur_req;
struct req_progress p;
int max_req_size;
int sram_size;
};
static struct crypto_priv *cpg;
struct mv_ctx {
u8 aes_enc_key[AES_KEY_LEN];
u32 aes_dec_key[8];
int key_len;
u32 need_calc_aes_dkey;
};
enum crypto_op {
COP_AES_ECB,
COP_AES_CBC,
};
struct mv_req_ctx {
enum crypto_op op;
int decrypt;
};
static void compute_aes_dec_key(struct mv_ctx *ctx)
{
struct crypto_aes_ctx gen_aes_key;
int key_pos;
if (!ctx->need_calc_aes_dkey)
return;
crypto_aes_expand_key(&gen_aes_key, ctx->aes_enc_key, ctx->key_len);
key_pos = ctx->key_len + 24;
memcpy(ctx->aes_dec_key, &gen_aes_key.key_enc[key_pos], 4 * 4);
switch (ctx->key_len) {
case AES_KEYSIZE_256:
key_pos -= 2;
/* fall */
case AES_KEYSIZE_192:
key_pos -= 2;
memcpy(&ctx->aes_dec_key[4], &gen_aes_key.key_enc[key_pos],
4 * 4);
break;
}
ctx->need_calc_aes_dkey = 0;
}
static int mv_setkey_aes(struct crypto_ablkcipher *cipher, const u8 *key,
unsigned int len)
{
struct crypto_tfm *tfm = crypto_ablkcipher_tfm(cipher);
struct mv_ctx *ctx = crypto_tfm_ctx(tfm);
switch (len) {
case AES_KEYSIZE_128:
case AES_KEYSIZE_192:
case AES_KEYSIZE_256:
break;
default:
crypto_ablkcipher_set_flags(cipher, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
}
ctx->key_len = len;
ctx->need_calc_aes_dkey = 1;
memcpy(ctx->aes_enc_key, key, AES_KEY_LEN);
return 0;
}
static void setup_data_in(struct ablkcipher_request *req)
{
int ret;
void *buf;
if (!cpg->p.sg_src_left) {
ret = sg_miter_next(&cpg->p.src_sg_it);
BUG_ON(!ret);
cpg->p.sg_src_left = cpg->p.src_sg_it.length;
cpg->p.src_start = 0;
}
cpg->p.crypt_len = min(cpg->p.sg_src_left, cpg->max_req_size);
buf = cpg->p.src_sg_it.addr;
buf += cpg->p.src_start;
memcpy(cpg->sram + SRAM_DATA_IN_START, buf, cpg->p.crypt_len);
cpg->p.sg_src_left -= cpg->p.crypt_len;
cpg->p.src_start += cpg->p.crypt_len;
}
static void mv_process_current_q(int first_block)
{
struct ablkcipher_request *req = cpg->cur_req;
struct mv_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
struct sec_accel_config op;
switch (req_ctx->op) {
case COP_AES_ECB:
op.config = CFG_OP_CRYPT_ONLY | CFG_ENCM_AES | CFG_ENC_MODE_ECB;
break;
case COP_AES_CBC:
default:
op.config = CFG_OP_CRYPT_ONLY | CFG_ENCM_AES | CFG_ENC_MODE_CBC;
op.enc_iv = ENC_IV_POINT(SRAM_DATA_IV) |
ENC_IV_BUF_POINT(SRAM_DATA_IV_BUF);
if (first_block)
memcpy(cpg->sram + SRAM_DATA_IV, req->info, 16);
break;
}
if (req_ctx->decrypt) {
op.config |= CFG_DIR_DEC;
memcpy(cpg->sram + SRAM_DATA_KEY_P, ctx->aes_dec_key,
AES_KEY_LEN);
} else {
op.config |= CFG_DIR_ENC;
memcpy(cpg->sram + SRAM_DATA_KEY_P, ctx->aes_enc_key,
AES_KEY_LEN);
}
switch (ctx->key_len) {
case AES_KEYSIZE_128:
op.config |= CFG_AES_LEN_128;
break;
case AES_KEYSIZE_192:
op.config |= CFG_AES_LEN_192;
break;
case AES_KEYSIZE_256:
op.config |= CFG_AES_LEN_256;
break;
}
op.enc_p = ENC_P_SRC(SRAM_DATA_IN_START) |
ENC_P_DST(SRAM_DATA_OUT_START);
op.enc_key_p = SRAM_DATA_KEY_P;
setup_data_in(req);
op.enc_len = cpg->p.crypt_len;
memcpy(cpg->sram + SRAM_CONFIG, &op,
sizeof(struct sec_accel_config));
writel(SRAM_CONFIG, cpg->reg + SEC_ACCEL_DESC_P0);
/* GO */
writel(SEC_CMD_EN_SEC_ACCL0, cpg->reg + SEC_ACCEL_CMD);
/*
* XXX: add timer if the interrupt does not occur for some mystery
* reason
*/
}
static void mv_crypto_algo_completion(void)
{
struct ablkcipher_request *req = cpg->cur_req;
struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
if (req_ctx->op != COP_AES_CBC)
return ;
memcpy(req->info, cpg->sram + SRAM_DATA_IV_BUF, 16);
}
static void dequeue_complete_req(void)
{
struct ablkcipher_request *req = cpg->cur_req;
void *buf;
int ret;
int need_copy_len = cpg->p.crypt_len;
int sram_offset = 0;
cpg->p.total_req_bytes += cpg->p.crypt_len;
do {
int dst_copy;
if (!cpg->p.sg_dst_left) {
ret = sg_miter_next(&cpg->p.dst_sg_it);
BUG_ON(!ret);
cpg->p.sg_dst_left = cpg->p.dst_sg_it.length;
cpg->p.dst_start = 0;
}
buf = cpg->p.dst_sg_it.addr;
buf += cpg->p.dst_start;
dst_copy = min(need_copy_len, cpg->p.sg_dst_left);
memcpy(buf,
cpg->sram + SRAM_DATA_OUT_START + sram_offset,
dst_copy);
sram_offset += dst_copy;
cpg->p.sg_dst_left -= dst_copy;
need_copy_len -= dst_copy;
cpg->p.dst_start += dst_copy;
} while (need_copy_len > 0);
BUG_ON(cpg->eng_st != ENGINE_W_DEQUEUE);
if (cpg->p.total_req_bytes < req->nbytes) {
/* process next scatter list entry */
cpg->eng_st = ENGINE_BUSY;
mv_process_current_q(0);
} else {
sg_miter_stop(&cpg->p.src_sg_it);
sg_miter_stop(&cpg->p.dst_sg_it);
mv_crypto_algo_completion();
cpg->eng_st = ENGINE_IDLE;
local_bh_disable();
req->base.complete(&req->base, 0);
local_bh_enable();
}
}
static int count_sgs(struct scatterlist *sl, unsigned int total_bytes)
{
int i = 0;
do {
total_bytes -= sl[i].length;
i++;
} while (total_bytes > 0);
return i;
}
static void mv_enqueue_new_req(struct ablkcipher_request *req)
{
int num_sgs;
cpg->cur_req = req;
memset(&cpg->p, 0, sizeof(struct req_progress));
num_sgs = count_sgs(req->src, req->nbytes);
sg_miter_start(&cpg->p.src_sg_it, req->src, num_sgs, SG_MITER_FROM_SG);
num_sgs = count_sgs(req->dst, req->nbytes);
sg_miter_start(&cpg->p.dst_sg_it, req->dst, num_sgs, SG_MITER_TO_SG);
mv_process_current_q(1);
}
static int queue_manag(void *data)
{
cpg->eng_st = ENGINE_IDLE;
do {
struct ablkcipher_request *req;
struct crypto_async_request *async_req = NULL;
struct crypto_async_request *backlog;
__set_current_state(TASK_INTERRUPTIBLE);
if (cpg->eng_st == ENGINE_W_DEQUEUE)
dequeue_complete_req();
spin_lock_irq(&cpg->lock);
if (cpg->eng_st == ENGINE_IDLE) {
backlog = crypto_get_backlog(&cpg->queue);
async_req = crypto_dequeue_request(&cpg->queue);
if (async_req) {
BUG_ON(cpg->eng_st != ENGINE_IDLE);
cpg->eng_st = ENGINE_BUSY;
}
}
spin_unlock_irq(&cpg->lock);
if (backlog) {
backlog->complete(backlog, -EINPROGRESS);
backlog = NULL;
}
if (async_req) {
req = container_of(async_req,
struct ablkcipher_request, base);
mv_enqueue_new_req(req);
async_req = NULL;
}
schedule();
} while (!kthread_should_stop());
return 0;
}
static int mv_handle_req(struct ablkcipher_request *req)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&cpg->lock, flags);
ret = ablkcipher_enqueue_request(&cpg->queue, req);
spin_unlock_irqrestore(&cpg->lock, flags);
wake_up_process(cpg->queue_th);
return ret;
}
static int mv_enc_aes_ecb(struct ablkcipher_request *req)
{
struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
req_ctx->op = COP_AES_ECB;
req_ctx->decrypt = 0;
return mv_handle_req(req);
}
static int mv_dec_aes_ecb(struct ablkcipher_request *req)
{
struct mv_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
req_ctx->op = COP_AES_ECB;
req_ctx->decrypt = 1;
compute_aes_dec_key(ctx);
return mv_handle_req(req);
}
static int mv_enc_aes_cbc(struct ablkcipher_request *req)
{
struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
req_ctx->op = COP_AES_CBC;
req_ctx->decrypt = 0;
return mv_handle_req(req);
}
static int mv_dec_aes_cbc(struct ablkcipher_request *req)
{
struct mv_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
req_ctx->op = COP_AES_CBC;
req_ctx->decrypt = 1;
compute_aes_dec_key(ctx);
return mv_handle_req(req);
}
static int mv_cra_init(struct crypto_tfm *tfm)
{
tfm->crt_ablkcipher.reqsize = sizeof(struct mv_req_ctx);
return 0;
}
irqreturn_t crypto_int(int irq, void *priv)
{
u32 val;
val = readl(cpg->reg + SEC_ACCEL_INT_STATUS);
if (!(val & SEC_INT_ACCEL0_DONE))
return IRQ_NONE;
val &= ~SEC_INT_ACCEL0_DONE;
writel(val, cpg->reg + FPGA_INT_STATUS);
writel(val, cpg->reg + SEC_ACCEL_INT_STATUS);
BUG_ON(cpg->eng_st != ENGINE_BUSY);
cpg->eng_st = ENGINE_W_DEQUEUE;
wake_up_process(cpg->queue_th);
return IRQ_HANDLED;
}
struct crypto_alg mv_aes_alg_ecb = {
.cra_name = "ecb(aes)",
.cra_driver_name = "mv-ecb-aes",
.cra_priority = 300,
.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
.cra_blocksize = 16,
.cra_ctxsize = sizeof(struct mv_ctx),
.cra_alignmask = 0,
.cra_type = &crypto_ablkcipher_type,
.cra_module = THIS_MODULE,
.cra_init = mv_cra_init,
.cra_u = {
.ablkcipher = {
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.setkey = mv_setkey_aes,
.encrypt = mv_enc_aes_ecb,
.decrypt = mv_dec_aes_ecb,
},
},
};
struct crypto_alg mv_aes_alg_cbc = {
.cra_name = "cbc(aes)",
.cra_driver_name = "mv-cbc-aes",
.cra_priority = 300,
.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct mv_ctx),
.cra_alignmask = 0,
.cra_type = &crypto_ablkcipher_type,
.cra_module = THIS_MODULE,
.cra_init = mv_cra_init,
.cra_u = {
.ablkcipher = {
.ivsize = AES_BLOCK_SIZE,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.setkey = mv_setkey_aes,
.encrypt = mv_enc_aes_cbc,
.decrypt = mv_dec_aes_cbc,
},
},
};
static int mv_probe(struct platform_device *pdev)
{
struct crypto_priv *cp;
struct resource *res;
int irq;
int ret;
if (cpg) {
printk(KERN_ERR "Second crypto dev?\n");
return -EEXIST;
}
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
if (!res)
return -ENXIO;
cp = kzalloc(sizeof(*cp), GFP_KERNEL);
if (!cp)
return -ENOMEM;
spin_lock_init(&cp->lock);
crypto_init_queue(&cp->queue, 50);
cp->reg = ioremap(res->start, res->end - res->start + 1);
if (!cp->reg) {
ret = -ENOMEM;
goto err;
}
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sram");
if (!res) {
ret = -ENXIO;
goto err_unmap_reg;
}
cp->sram_size = res->end - res->start + 1;
cp->max_req_size = cp->sram_size - SRAM_CFG_SPACE;
cp->sram = ioremap(res->start, cp->sram_size);
if (!cp->sram) {
ret = -ENOMEM;
goto err_unmap_reg;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0 || irq == NO_IRQ) {
ret = irq;
goto err_unmap_sram;
}
cp->irq = irq;
platform_set_drvdata(pdev, cp);
cpg = cp;
cp->queue_th = kthread_run(queue_manag, cp, "mv_crypto");
if (IS_ERR(cp->queue_th)) {
ret = PTR_ERR(cp->queue_th);
goto err_thread;
}
ret = request_irq(irq, crypto_int, IRQF_DISABLED, dev_name(&pdev->dev),
cp);
if (ret)
goto err_unmap_sram;
writel(SEC_INT_ACCEL0_DONE, cpg->reg + SEC_ACCEL_INT_MASK);
writel(SEC_CFG_STOP_DIG_ERR, cpg->reg + SEC_ACCEL_CFG);
ret = crypto_register_alg(&mv_aes_alg_ecb);
if (ret)
goto err_reg;
ret = crypto_register_alg(&mv_aes_alg_cbc);
if (ret)
goto err_unreg_ecb;
return 0;
err_unreg_ecb:
crypto_unregister_alg(&mv_aes_alg_ecb);
err_thread:
free_irq(irq, cp);
err_reg:
kthread_stop(cp->queue_th);
err_unmap_sram:
iounmap(cp->sram);
err_unmap_reg:
iounmap(cp->reg);
err:
kfree(cp);
cpg = NULL;
platform_set_drvdata(pdev, NULL);
return ret;
}
static int mv_remove(struct platform_device *pdev)
{
struct crypto_priv *cp = platform_get_drvdata(pdev);
crypto_unregister_alg(&mv_aes_alg_ecb);
crypto_unregister_alg(&mv_aes_alg_cbc);
kthread_stop(cp->queue_th);
free_irq(cp->irq, cp);
memset(cp->sram, 0, cp->sram_size);
iounmap(cp->sram);
iounmap(cp->reg);
kfree(cp);
cpg = NULL;
return 0;
}
static struct platform_driver marvell_crypto = {
.probe = mv_probe,
.remove = mv_remove,
.driver = {
.owner = THIS_MODULE,
.name = "mv_crypto",
},
};
MODULE_ALIAS("platform:mv_crypto");
static int __init mv_crypto_init(void)
{
return platform_driver_register(&marvell_crypto);
}
module_init(mv_crypto_init);
static void __exit mv_crypto_exit(void)
{
platform_driver_unregister(&marvell_crypto);
}
module_exit(mv_crypto_exit);
MODULE_AUTHOR("Sebastian Andrzej Siewior <sebastian@breakpoint.cc>");
MODULE_DESCRIPTION("Support for Marvell's cryptographic engine");
MODULE_LICENSE("GPL");