From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aMGfq-0000Qo-GB for barebox@lists.infradead.org; Thu, 21 Jan 2016 14:57:25 +0000 From: Steffen Trumtrar Date: Thu, 21 Jan 2016 15:55:51 +0100 Message-Id: <1453388151-8424-4-git-send-email-s.trumtrar@pengutronix.de> In-Reply-To: <1453388151-8424-1-git-send-email-s.trumtrar@pengutronix.de> References: <1453388151-8424-1-git-send-email-s.trumtrar@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH v2 3/3] crypto: caam: add RNG support To: barebox@lists.infradead.org Cc: Steffen Trumtrar Add suport for the i.MX6 CAAM RNG module. The device is registered as a char-device under /dev/hwrng to mimic the linux userspace interface. Signed-off-by: Steffen Trumtrar Signed-off-by: Marc Kleine-Budde --- drivers/crypto/caam/Kconfig | 7 + drivers/crypto/caam/Makefile | 1 + drivers/crypto/caam/caamrng.c | 313 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 321 insertions(+) create mode 100644 drivers/crypto/caam/caamrng.c diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig index d54754c7a89b..4bf1c937c9a5 100644 --- a/drivers/crypto/caam/Kconfig +++ b/drivers/crypto/caam/Kconfig @@ -35,3 +35,10 @@ config CRYPTO_DEV_FSL_CAAM_RINGSIZE 7 => 128 8 => 256 9 => 512 + +config CRYPTO_DEV_FSL_CAAM_RNG + bool "Register caam RNG device" + depends on CRYPTO_DEV_FSL_CAAM && CRYPTO_DEV_FSL_CAAM_JR + default n + help + Selecting this will register the SEC4 hardware rng. diff --git a/drivers/crypto/caam/Makefile b/drivers/crypto/caam/Makefile index cd46936fb6b4..ea63f5894441 100644 --- a/drivers/crypto/caam/Makefile +++ b/drivers/crypto/caam/Makefile @@ -3,3 +3,4 @@ # obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM) += ctrl.o error.o obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM_JR) += jr.o +obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM_RNG) += caamrng.o diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c new file mode 100644 index 000000000000..fc1ed3f4987c --- /dev/null +++ b/drivers/crypto/caam/caamrng.c @@ -0,0 +1,313 @@ +/* + * caam - Freescale FSL CAAM support for hw_random + * + * Copyright (C) 2011-2015 Freescale Semiconductor, Inc. + * + * Based on caamalg.c crypto API driver. + * + * relationship between job descriptors to shared descriptors: + * + * --------------- -------------- + * | JobDesc #0 |-------------------->| ShareDesc | + * | *(buffer 0) | |------------->| (generate) | + * --------------- | | (move) | + * | | (store) | + * --------------- | -------------- + * | JobDesc #1 |------| + * | *(buffer 1) | + * --------------- + * + * A job desc looks like this: + * + * --------------------- + * | Header | + * | ShareDesc Pointer | + * | SEQ_OUT_PTR | + * | (output buffer) | + * --------------------- + * + * The SharedDesc never changes, and each job descriptor points to one of two + * buffers for each device, from which the data will be copied into the + * requested destination + */ +#include +#include +#include +#include + +#include "regs.h" +#include "intern.h" +#include "desc_constr.h" +#include "jr.h" +#include "error.h" + +/* + * Maximum buffer size: maximum number of random, cache-aligned bytes that + * will be generated and moved to seq out ptr (extlen not allowed) + */ +#define RN_BUF_SIZE 32767 + +/* length of descriptors */ +#define DESC_JOB_O_LEN (CAAM_CMD_SZ * 2 + CAAM_PTR_SZ * 2) +#define DESC_RNG_LEN (10 * CAAM_CMD_SZ) + +/* Buffer, its dma address and lock */ +struct buf_data { + u8 buf[RN_BUF_SIZE]; + dma_addr_t addr; + u32 hw_desc[DESC_JOB_O_LEN]; +#define BUF_NOT_EMPTY 0 +#define BUF_EMPTY 1 +#define BUF_PENDING 2 /* Empty, but with job pending --don't submit another */ + int empty; +}; + +/* rng per-device context */ +struct caam_rng_ctx { + struct device_d *jrdev; + dma_addr_t sh_desc_dma; + u32 sh_desc[DESC_RNG_LEN]; + unsigned int cur_buf_idx; + int current_buf; + struct buf_data bufs[2]; + struct cdev cdev; +}; + +static struct caam_rng_ctx *rng_ctx; + +static void rng_done(struct device_d *jrdev, u32 *desc, u32 err, void *context) +{ + struct buf_data *bd; + + bd = (struct buf_data *)((char *)desc - + offsetof(struct buf_data, hw_desc)); + + if (err) + caam_jr_strstatus(jrdev, err); + + bd->empty = BUF_NOT_EMPTY; + + /* Buffer refilled, invalidate cache */ + dma_sync_single_for_cpu(bd->addr, RN_BUF_SIZE, DMA_FROM_DEVICE); + +#ifdef DEBUG + print_hex_dump(KERN_ERR, "rng refreshed buf@: ", + DUMP_PREFIX_OFFSET, 16, 4, bd->buf, RN_BUF_SIZE, 1); +#endif +} + +static inline int submit_job(struct caam_rng_ctx *ctx, int to_current) +{ + struct buf_data *bd = &ctx->bufs[!(to_current ^ ctx->current_buf)]; + struct device_d *jrdev = ctx->jrdev; + u32 *desc = bd->hw_desc; + int err; + + dev_dbg(jrdev, "submitting job %d\n", !(to_current ^ ctx->current_buf)); + + dma_sync_single_for_device((unsigned long)desc, desc_bytes(desc), DMA_TO_DEVICE); + + err = caam_jr_enqueue(jrdev, desc, rng_done, ctx); + if (!err) + bd->empty += 1; /* note if pending */ + + return err; +} + +static int caam_read(struct caam_rng_ctx *ctx, void *data, size_t max, bool wait) +{ + struct buf_data *bd = &ctx->bufs[ctx->current_buf]; + int next_buf_idx, copied_idx; + int err; + + if (bd->empty) { + /* try to submit job if there wasn't one */ + if (bd->empty == BUF_EMPTY) { + err = submit_job(ctx, 1); + /* if can't submit job, can't even wait */ + if (err) + return 0; + } + /* no immediate data, so exit if not waiting */ + if (!wait) + return 0; + } + + next_buf_idx = ctx->cur_buf_idx + max; + dev_dbg(ctx->jrdev, "%s: start reading at buffer %d, idx %d\n", + __func__, ctx->current_buf, ctx->cur_buf_idx); + + /* if enough data in current buffer */ + if (next_buf_idx < RN_BUF_SIZE) { + memcpy(data, bd->buf + ctx->cur_buf_idx, max); + ctx->cur_buf_idx = next_buf_idx; + return max; + } + + /* else, copy what's left... */ + copied_idx = RN_BUF_SIZE - ctx->cur_buf_idx; + memcpy(data, bd->buf + ctx->cur_buf_idx, copied_idx); + ctx->cur_buf_idx = 0; + bd->empty = BUF_EMPTY; + + /* ...refill... */ + submit_job(ctx, 1); + + /* and use next buffer */ + ctx->current_buf = !ctx->current_buf; + dev_dbg(ctx->jrdev, "switched to buffer %d\n", ctx->current_buf); + + /* since there already is some data read, don't wait */ + return copied_idx + caam_read(ctx, data + copied_idx, + max - copied_idx, false); +} + +static inline int rng_create_sh_desc(struct caam_rng_ctx *ctx) +{ + u32 *desc = ctx->sh_desc; + + init_sh_desc(desc, HDR_SHARE_SERIAL); + + /* Propagate errors from shared to job descriptor */ + append_cmd(desc, SET_OK_NO_PROP_ERRORS | CMD_LOAD); + + /* Generate random bytes */ + append_operation(desc, OP_ALG_ALGSEL_RNG | OP_TYPE_CLASS1_ALG); + + /* Store bytes */ + append_seq_fifo_store(desc, RN_BUF_SIZE, FIFOST_TYPE_RNGSTORE); + + ctx->sh_desc_dma = (dma_addr_t)desc; + + dma_sync_single_for_device((unsigned long)desc, desc_bytes(desc), DMA_TO_DEVICE); +#ifdef DEBUG + print_hex_dump(KERN_ERR, "rng shdesc@: ", DUMP_PREFIX_OFFSET, 16, 4, + desc, desc_bytes(desc), 1); +#endif + return 0; +} + +static inline int rng_create_job_desc(struct caam_rng_ctx *ctx, int buf_id) +{ + struct buf_data *bd = &ctx->bufs[buf_id]; + u32 *desc = bd->hw_desc; + int sh_len = desc_len(ctx->sh_desc); + + init_job_desc_shared(desc, ctx->sh_desc_dma, sh_len, HDR_SHARE_DEFER | + HDR_REVERSE); + + bd->addr = (dma_addr_t)bd->buf; + + append_seq_out_ptr_intlen(desc, bd->addr, RN_BUF_SIZE, 0); +#ifdef DEBUG + print_hex_dump(KERN_ERR, "rng job desc@: ", DUMP_PREFIX_OFFSET, 16, 4, + desc, desc_bytes(desc), 1); +#endif + return 0; +} + +static int caam_init_buf(struct caam_rng_ctx *ctx, int buf_id) +{ + struct buf_data *bd = &ctx->bufs[buf_id]; + int err; + + err = rng_create_job_desc(ctx, buf_id); + if (err) + return err; + + bd->empty = BUF_EMPTY; + submit_job(ctx, buf_id == ctx->current_buf); + + return 0; +} + +static int caam_init_rng(struct caam_rng_ctx *ctx, struct device_d *jrdev) +{ + int err; + + ctx->jrdev = jrdev; + + err = rng_create_sh_desc(ctx); + if (err) + return err; + + ctx->current_buf = 0; + ctx->cur_buf_idx = 0; + + err = caam_init_buf(ctx, 0); + if (err) + return err; + + err = caam_init_buf(ctx, 1); + if (err) + return err; + + return 0; +} + +static ssize_t random_read(struct cdev *cdev, void *buf, size_t count, loff_t offset, ulong flags) +{ + struct caam_rng_ctx *ctx = container_of(cdev, struct caam_rng_ctx, cdev); + + return caam_read(ctx, buf, count, true); +} + +static struct file_operations randomops = { + .read = random_read, + .lseek = dev_lseek_default, +}; + +static int caam_init_devrandom(struct caam_rng_ctx *ctx, struct device_d *jrdev) +{ + ctx->cdev.name = "hwrng"; + ctx->cdev.flags = DEVFS_IS_CHARACTER_DEV; + ctx->cdev.ops = &randomops; + ctx->cdev.dev = jrdev; + + return devfs_create(&ctx->cdev); +} + +static int caam_rng_probe(struct device_d *d) +{ + struct device_d *dev; + struct device_node *dev_node; + int err; + + dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec-v4.0-job-ring"); + if (!dev_node) { + dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec4.0-job-ring"); + if (!dev_node) + return -ENODEV; + } + + dev = of_find_device_by_node(dev_node); + if (!dev) + return -ENODEV; + rng_ctx = xzalloc(sizeof(*rng_ctx)); + + err = caam_init_rng(rng_ctx, dev); + if (err) + return err; + + err = caam_init_devrandom(rng_ctx, dev); + if (err) + return err; + + dev_info(d, "registering rng-caam\n"); + + return 0; +} + +static struct of_device_id caam_rng_ids[] = { + { + .compatible = "caam_rng", + }, + {}, +}; + +static struct driver_d caam_rng_driver = { + .name = "caam_rng", + .of_compatible = DRV_OF_COMPAT(caam_rng_ids), + .probe = caam_rng_probe, +}; +device_platform_driver(caam_rng_driver); -- 2.7.0.rc3 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox