diff options
Diffstat (limited to 'drivers/crypto/mv_cesa.c')
-rw-r--r-- | drivers/crypto/mv_cesa.c | 606 |
1 files changed, 606 insertions, 0 deletions
diff --git a/drivers/crypto/mv_cesa.c b/drivers/crypto/mv_cesa.c new file mode 100644 index 000000000000..b21ef635f352 --- /dev/null +++ b/drivers/crypto/mv_cesa.c @@ -0,0 +1,606 @@ +/* + * 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: + 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; + + 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(cpg->p.crypt_len, cpg->p.sg_dst_left); + + memcpy(buf, cpg->sram + SRAM_DATA_OUT_START, dst_copy); + + cpg->p.sg_dst_left -= dst_copy; + cpg->p.crypt_len -= dst_copy; + cpg->p.dst_start += dst_copy; + } while (cpg->p.crypt_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; + req->base.complete(&req->base, 0); + } +} + +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"); |