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

// SPDX-License-Identifier: GPL-2.0+
/*
 * caam - Freescale FSL CAAM support for hw_random
 *
 * Copyright 2011 Freescale Semiconductor, Inc.
 * Copyright 2018 NXP
 *
 * 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 <linux/hw_random.h>
#include <linux/completion.h>
#include <linux/atomic.h>

#include "compat.h"

#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			(0xffff / L1_CACHE_BYTES * \
					 L1_CACHE_BYTES)

/* length of descriptors */
#define DESC_JOB_O_LEN			(CAAM_CMD_SZ * 2 + CAAM_PTR_SZ * 2)
#define DESC_RNG_LEN			(3 * CAAM_CMD_SZ)

/* Buffer, its dma address and lock */
struct buf_data {
	u8 buf[RN_BUF_SIZE] ____cacheline_aligned;
	dma_addr_t addr;
	struct completion filled;
	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 */
	atomic_t empty;
};

/* rng per-device context */
struct caam_rng_ctx {
	struct device *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];
};

static struct caam_rng_ctx *rng_ctx;

static inline void rng_unmap_buf(struct device *jrdev, struct buf_data *bd)
{
	if (bd->addr)
		dma_unmap_single(jrdev, bd->addr, RN_BUF_SIZE,
				 DMA_FROM_DEVICE);
}

static inline void rng_unmap_ctx(struct caam_rng_ctx *ctx)
{
	struct device *jrdev = ctx->jrdev;

	if (ctx->sh_desc_dma)
		dma_unmap_single(jrdev, ctx->sh_desc_dma,
				 desc_bytes(ctx->sh_desc), DMA_TO_DEVICE);
	rng_unmap_buf(jrdev, &ctx->bufs[0]);
	rng_unmap_buf(jrdev, &ctx->bufs[1]);
}

static void rng_done(struct device *jrdev, u32 *desc, u32 err, void *context)
{
	struct buf_data *bd;

	bd = container_of(desc, struct buf_data, hw_desc[0]);

	if (err)
		caam_jr_strstatus(jrdev, err);

	atomic_set(&bd->empty, BUF_NOT_EMPTY);
	complete(&bd->filled);

	/* Buffer refilled, invalidate cache */
	dma_sync_single_for_cpu(jrdev, bd->addr, RN_BUF_SIZE, DMA_FROM_DEVICE);

#ifdef DEBUG
	print_hex_dump(KERN_ERR, "rng refreshed buf@: ",
		       DUMP_PREFIX_ADDRESS, 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 *jrdev = ctx->jrdev;
	u32 *desc = bd->hw_desc;
	int err;

	dev_dbg(jrdev, "submitting job %d\n", !(to_current ^ ctx->current_buf));
	init_completion(&bd->filled);
	err = caam_jr_enqueue(jrdev, desc, rng_done, ctx);
	if (err)
		complete(&bd->filled); /* don't wait on failed job*/
	else
		atomic_inc(&bd->empty); /* note if pending */

	return err;
}

static int caam_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
	struct caam_rng_ctx *ctx = rng_ctx;
	struct buf_data *bd = &ctx->bufs[ctx->current_buf];
	int next_buf_idx, copied_idx;
	int err;

	if (atomic_read(&bd->empty)) {
		/* try to submit job if there wasn't one */
		if (atomic_read(&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;

		/* waiting for pending job */
		if (atomic_read(&bd->empty))
			wait_for_completion(&bd->filled);
	}

	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;
	atomic_set(&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(rng, data + copied_idx,
				      max - copied_idx, false);
}

static inline int rng_create_sh_desc(struct caam_rng_ctx *ctx)
{
	struct device *jrdev = ctx->jrdev;
	u32 *desc = ctx->sh_desc;

	init_sh_desc(desc, HDR_SHARE_SERIAL);

	/* 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_map_single(jrdev, desc, desc_bytes(desc),
					  DMA_TO_DEVICE);
	if (dma_mapping_error(jrdev, ctx->sh_desc_dma)) {
		dev_err(jrdev, "unable to map shared descriptor\n");
		return -ENOMEM;
	}
#ifdef DEBUG
	print_hex_dump(KERN_ERR, "rng shdesc@: ", DUMP_PREFIX_ADDRESS, 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 device *jrdev = ctx->jrdev;
	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_map_single(jrdev, bd->buf, RN_BUF_SIZE, DMA_FROM_DEVICE);
	if (dma_mapping_error(jrdev, bd->addr)) {
		dev_err(jrdev, "unable to map dst\n");
		return -ENOMEM;
	}

	append_seq_out_ptr_intlen(desc, bd->addr, RN_BUF_SIZE, 0);
#ifdef DEBUG
	print_hex_dump(KERN_ERR, "rng job desc@: ", DUMP_PREFIX_ADDRESS, 16, 4,
		       desc, desc_bytes(desc), 1);
#endif
	return 0;
}

static void caam_cleanup(struct hwrng *rng)
{
	int i;
	struct buf_data *bd;

	for (i = 0; i < 2; i++) {
		bd = &rng_ctx->bufs[i];
		if (atomic_read(&bd->empty) == BUF_PENDING)
			wait_for_completion(&bd->filled);
	}

	rng_unmap_ctx(rng_ctx);
}

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;

	atomic_set(&bd->empty, BUF_EMPTY);
	submit_job(ctx, buf_id == ctx->current_buf);
	wait_for_completion(&bd->filled);

	return 0;
}

static int caam_init_rng(struct caam_rng_ctx *ctx, struct device *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;

	return caam_init_buf(ctx, 1);
}

static struct hwrng caam_rng = {
	.name		= "rng-caam",
	.cleanup	= caam_cleanup,
	.read		= caam_read,
};

static void __exit caam_rng_exit(void)
{
	caam_jr_free(rng_ctx->jrdev);
	hwrng_unregister(&caam_rng);
	kfree(rng_ctx);
}

static int __init caam_rng_init(void)
{
	struct device *dev;
	struct device_node *dev_node;
	struct platform_device *pdev;
	struct device *ctrldev;
	struct caam_drv_private *priv;
	u32 rng_inst;
	int err;

	dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec-v4.0");
	if (!dev_node) {
		dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec4.0");
		if (!dev_node)
			return -ENODEV;
	}

	pdev = of_find_device_by_node(dev_node);
	if (!pdev) {
		of_node_put(dev_node);
		return -ENODEV;
	}

	ctrldev = &pdev->dev;
	priv = dev_get_drvdata(ctrldev);
	of_node_put(dev_node);

	/*
	 * If priv is NULL, it's probably because the caam driver wasn't
	 * properly initialized (e.g. RNG4 init failed). Thus, bail out here.
	 */
	if (!priv)
		return -ENODEV;

	/* Check for an instantiated RNG before registration */
	if (priv->era < 10)
		rng_inst = (rd_reg32(&priv->ctrl->perfmon.cha_num_ls) &
			    CHA_ID_LS_RNG_MASK) >> CHA_ID_LS_RNG_SHIFT;
	else
		rng_inst = rd_reg32(&priv->ctrl->vreg.rng) & CHA_VER_NUM_MASK;

	if (!rng_inst)
		return -ENODEV;

	dev = caam_jr_alloc();
	if (IS_ERR(dev)) {
		pr_err("Job Ring Device allocation for transform failed\n");
		return PTR_ERR(dev);
	}
	rng_ctx = kmalloc(sizeof(*rng_ctx), GFP_DMA | GFP_KERNEL);
	if (!rng_ctx) {
		err = -ENOMEM;
		goto free_caam_alloc;
	}
	err = caam_init_rng(rng_ctx, dev);
	if (err)
		goto free_rng_ctx;

	dev_info(dev, "registering rng-caam\n");
	return hwrng_register(&caam_rng);

free_rng_ctx:
	kfree(rng_ctx);
free_caam_alloc:
	caam_jr_free(dev);
	return err;
}

module_init(caam_rng_init);
module_exit(caam_rng_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("FSL CAAM support for hw_random API");
MODULE_AUTHOR("Freescale Semiconductor - NMG");
Commit	Line	Data
618b5dc4	1	// SPDX-License-Identifier: GPL-2.0+
e24f7c9e YK	2	/*
	3	* caam - Freescale FSL CAAM support for hw_random
	4	*
	5	* Copyright 2011 Freescale Semiconductor, Inc.
d239b10d	6	* Copyright 2018 NXP
e24f7c9e YK	7	*
	8	* Based on caamalg.c crypto API driver.
	9	*
	10	* relationship between job descriptors to shared descriptors:
	11	*
	12	* --------------- --------------
	13	* \| JobDesc #0 \|-------------------->\| ShareDesc \|
	14	* \| *(buffer 0) \| \|------------->\| (generate) \|
	15	* --------------- \| \| (move) \|
	16	* \| \| (store) \|
	17	* --------------- \| --------------
	18	* \| JobDesc #1 \|------\|
	19	* \| *(buffer 1) \|
	20	* ---------------
	21	*
	22	* A job desc looks like this:
	23	*
	24	* ---------------------
	25	* \| Header \|
	26	* \| ShareDesc Pointer \|
	27	* \| SEQ_OUT_PTR \|
	28	* \| (output buffer) \|
	29	* ---------------------
	30	*
	31	* The SharedDesc never changes, and each job descriptor points to one of two
	32	* buffers for each device, from which the data will be copied into the
	33	* requested destination
	34	*/
	35
	36	#include <linux/hw_random.h>
	37	#include <linux/completion.h>
	38	#include <linux/atomic.h>
	39
	40	#include "compat.h"
	41
	42	#include "regs.h"
	43	#include "intern.h"
	44	#include "desc_constr.h"
	45	#include "jr.h"
	46	#include "error.h"
	47
	48	/*
	49	* Maximum buffer size: maximum number of random, cache-aligned bytes that
	50	* will be generated and moved to seq out ptr (extlen not allowed)
	51	*/
	52	#define RN_BUF_SIZE (0xffff / L1_CACHE_BYTES * \
	53	L1_CACHE_BYTES)
	54
	55	/* length of descriptors */
	56	#define DESC_JOB_O_LEN (CAAM_CMD_SZ * 2 + CAAM_PTR_SZ * 2)
39957c8e	57	#define DESC_RNG_LEN (3 * CAAM_CMD_SZ)
e24f7c9e YK	58
	59	/* Buffer, its dma address and lock */
	60	struct buf_data {
412c98c1	61	u8 buf[RN_BUF_SIZE] ____cacheline_aligned;
e24f7c9e YK	62	dma_addr_t addr;
	63	struct completion filled;
	64	u32 hw_desc[DESC_JOB_O_LEN];
	65	#define BUF_NOT_EMPTY 0
	66	#define BUF_EMPTY 1
	67	#define BUF_PENDING 2 /* Empty, but with job pending --don't submit another */
	68	atomic_t empty;
	69	};
	70
	71	/* rng per-device context */
	72	struct caam_rng_ctx {
	73	struct device *jrdev;
	74	dma_addr_t sh_desc_dma;
	75	u32 sh_desc[DESC_RNG_LEN];
	76	unsigned int cur_buf_idx;
	77	int current_buf;
	78	struct buf_data bufs[2];
	79	};
	80
6e4e603a	81	static struct caam_rng_ctx *rng_ctx;
e24f7c9e YK	82
	83	static inline void rng_unmap_buf(struct device jrdev, struct buf_data bd)
	84	{
	85	if (bd->addr)
	86	dma_unmap_single(jrdev, bd->addr, RN_BUF_SIZE,
	87	DMA_FROM_DEVICE);
	88	}
	89
	90	static inline void rng_unmap_ctx(struct caam_rng_ctx *ctx)
	91	{
	92	struct device *jrdev = ctx->jrdev;
	93
	94	if (ctx->sh_desc_dma)
4842234f YJ	95	dma_unmap_single(jrdev, ctx->sh_desc_dma,
4842234f YJ	96	desc_bytes(ctx->sh_desc), DMA_TO_DEVICE);
e24f7c9e YK	97	rng_unmap_buf(jrdev, &ctx->bufs[0]);
	98	rng_unmap_buf(jrdev, &ctx->bufs[1]);
	99	}
	100
	101	static void rng_done(struct device jrdev, u32 desc, u32 err, void *context)
	102	{
	103	struct buf_data *bd;
	104
4ca7c7d8	105	bd = container_of(desc, struct buf_data, hw_desc[0]);
e24f7c9e	106
fa9659cd MV	107	if (err)
fa9659cd MV	108	caam_jr_strstatus(jrdev, err);
e24f7c9e YK	109
	110	atomic_set(&bd->empty, BUF_NOT_EMPTY);
	111	complete(&bd->filled);
e7472422 VM	112
	113	/* Buffer refilled, invalidate cache */
	114	dma_sync_single_for_cpu(jrdev, bd->addr, RN_BUF_SIZE, DMA_FROM_DEVICE);
	115
e24f7c9e YK	116	#ifdef DEBUG
	117	print_hex_dump(KERN_ERR, "rng refreshed buf@: ",
	118	DUMP_PREFIX_ADDRESS, 16, 4, bd->buf, RN_BUF_SIZE, 1);
	119	#endif
	120	}
	121
	122	static inline int submit_job(struct caam_rng_ctx *ctx, int to_current)
	123	{
	124	struct buf_data *bd = &ctx->bufs[!(to_current ^ ctx->current_buf)];
	125	struct device *jrdev = ctx->jrdev;
	126	u32 *desc = bd->hw_desc;
	127	int err;
	128
	129	dev_dbg(jrdev, "submitting job %d\n", !(to_current ^ ctx->current_buf));
	130	init_completion(&bd->filled);
	131	err = caam_jr_enqueue(jrdev, desc, rng_done, ctx);
	132	if (err)
	133	complete(&bd->filled); /* don't wait on failed job*/
	134	else
	135	atomic_inc(&bd->empty); /* note if pending */
	136
	137	return err;
	138	}
	139
	140	static int caam_read(struct hwrng rng, void data, size_t max, bool wait)
	141	{
6e4e603a	142	struct caam_rng_ctx *ctx = rng_ctx;
e24f7c9e YK	143	struct buf_data *bd = &ctx->bufs[ctx->current_buf];
	144	int next_buf_idx, copied_idx;
	145	int err;
	146
	147	if (atomic_read(&bd->empty)) {
	148	/* try to submit job if there wasn't one */
	149	if (atomic_read(&bd->empty) == BUF_EMPTY) {
	150	err = submit_job(ctx, 1);
	151	/* if can't submit job, can't even wait */
	152	if (err)
	153	return 0;
	154	}
	155	/* no immediate data, so exit if not waiting */
	156	if (!wait)
	157	return 0;
	158
	159	/* waiting for pending job */
	160	if (atomic_read(&bd->empty))
	161	wait_for_completion(&bd->filled);
	162	}
	163
	164	next_buf_idx = ctx->cur_buf_idx + max;
	165	dev_dbg(ctx->jrdev, "%s: start reading at buffer %d, idx %d\n",
	166	__func__, ctx->current_buf, ctx->cur_buf_idx);
	167
	168	/* if enough data in current buffer */
	169	if (next_buf_idx < RN_BUF_SIZE) {
	170	memcpy(data, bd->buf + ctx->cur_buf_idx, max);
	171	ctx->cur_buf_idx = next_buf_idx;
	172	return max;
	173	}
	174
	175	/* else, copy what's left... */
	176	copied_idx = RN_BUF_SIZE - ctx->cur_buf_idx;
	177	memcpy(data, bd->buf + ctx->cur_buf_idx, copied_idx);
	178	ctx->cur_buf_idx = 0;
	179	atomic_set(&bd->empty, BUF_EMPTY);
	180
	181	/* ...refill... */
	182	submit_job(ctx, 1);
	183
	184	/* and use next buffer */
	185	ctx->current_buf = !ctx->current_buf;
	186	dev_dbg(ctx->jrdev, "switched to buffer %d\n", ctx->current_buf);
	187
	188	/* since there already is some data read, don't wait */
	189	return copied_idx + caam_read(rng, data + copied_idx,
	190	max - copied_idx, false);
	191	}
	192
ce572085	193	static inline int rng_create_sh_desc(struct caam_rng_ctx *ctx)
e24f7c9e YK	194	{
	195	struct device *jrdev = ctx->jrdev;
	196	u32 *desc = ctx->sh_desc;
	197
61bb86bb	198	init_sh_desc(desc, HDR_SHARE_SERIAL);
e24f7c9e	199
e24f7c9e YK	200	/* Generate random bytes */
	201	append_operation(desc, OP_ALG_ALGSEL_RNG \| OP_TYPE_CLASS1_ALG);
	202
	203	/* Store bytes */
	204	append_seq_fifo_store(desc, RN_BUF_SIZE, FIFOST_TYPE_RNGSTORE);
	205
	206	ctx->sh_desc_dma = dma_map_single(jrdev, desc, desc_bytes(desc),
	207	DMA_TO_DEVICE);
ce572085 HG	208	if (dma_mapping_error(jrdev, ctx->sh_desc_dma)) {
	209	dev_err(jrdev, "unable to map shared descriptor\n");
	210	return -ENOMEM;
	211	}
e24f7c9e YK	212	#ifdef DEBUG
	213	print_hex_dump(KERN_ERR, "rng shdesc@: ", DUMP_PREFIX_ADDRESS, 16, 4,
	214	desc, desc_bytes(desc), 1);
	215	#endif
ce572085	216	return 0;
e24f7c9e YK	217	}
e24f7c9e YK	218
ce572085	219	static inline int rng_create_job_desc(struct caam_rng_ctx *ctx, int buf_id)
e24f7c9e YK	220	{
	221	struct device *jrdev = ctx->jrdev;
	222	struct buf_data *bd = &ctx->bufs[buf_id];
	223	u32 *desc = bd->hw_desc;
	224	int sh_len = desc_len(ctx->sh_desc);
	225
	226	init_job_desc_shared(desc, ctx->sh_desc_dma, sh_len, HDR_SHARE_DEFER \|
	227	HDR_REVERSE);
	228
	229	bd->addr = dma_map_single(jrdev, bd->buf, RN_BUF_SIZE, DMA_FROM_DEVICE);
ce572085 HG	230	if (dma_mapping_error(jrdev, bd->addr)) {
	231	dev_err(jrdev, "unable to map dst\n");
	232	return -ENOMEM;
	233	}
e24f7c9e YK	234
	235	append_seq_out_ptr_intlen(desc, bd->addr, RN_BUF_SIZE, 0);
	236	#ifdef DEBUG
	237	print_hex_dump(KERN_ERR, "rng job desc@: ", DUMP_PREFIX_ADDRESS, 16, 4,
	238	desc, desc_bytes(desc), 1);
	239	#endif
ce572085	240	return 0;
e24f7c9e YK	241	}
	242
	243	static void caam_cleanup(struct hwrng *rng)
	244	{
	245	int i;
	246	struct buf_data *bd;
	247
	248	for (i = 0; i < 2; i++) {
6e4e603a	249	bd = &rng_ctx->bufs[i];
e24f7c9e YK	250	if (atomic_read(&bd->empty) == BUF_PENDING)
	251	wait_for_completion(&bd->filled);
	252	}
	253
6e4e603a	254	rng_unmap_ctx(rng_ctx);
e24f7c9e YK	255	}
e24f7c9e YK	256
ce572085	257	static int caam_init_buf(struct caam_rng_ctx *ctx, int buf_id)
e24f7c9e YK	258	{
e24f7c9e YK	259	struct buf_data *bd = &ctx->bufs[buf_id];
ce572085 HG	260	int err;
	261
	262	err = rng_create_job_desc(ctx, buf_id);
	263	if (err)
	264	return err;
e24f7c9e	265
e24f7c9e YK	266	atomic_set(&bd->empty, BUF_EMPTY);
	267	submit_job(ctx, buf_id == ctx->current_buf);
	268	wait_for_completion(&bd->filled);
ce572085 HG	269
ce572085 HG	270	return 0;
e24f7c9e YK	271	}
e24f7c9e YK	272
ce572085	273	static int caam_init_rng(struct caam_rng_ctx ctx, struct device jrdev)
e24f7c9e	274	{
ce572085 HG	275	int err;
ce572085 HG	276
e24f7c9e	277	ctx->jrdev = jrdev;
ce572085 HG	278
	279	err = rng_create_sh_desc(ctx);
	280	if (err)
	281	return err;
	282
e24f7c9e YK	283	ctx->current_buf = 0;
e24f7c9e YK	284	ctx->cur_buf_idx = 0;
ce572085 HG	285
	286	err = caam_init_buf(ctx, 0);
	287	if (err)
	288	return err;
	289
f366af46	290	return caam_init_buf(ctx, 1);
e24f7c9e YK	291	}
	292
	293	static struct hwrng caam_rng = {
	294	.name = "rng-caam",
	295	.cleanup = caam_cleanup,
	296	.read = caam_read,
	297	};
	298
	299	static void __exit caam_rng_exit(void)
	300	{
6e4e603a	301	caam_jr_free(rng_ctx->jrdev);
e24f7c9e	302	hwrng_unregister(&caam_rng);
6e4e603a	303	kfree(rng_ctx);
e24f7c9e YK	304	}
	305
	306	static int __init caam_rng_init(void)
	307	{
cfc6f11b	308	struct device *dev;
35af6403 RG	309	struct device_node *dev_node;
	310	struct platform_device *pdev;
	311	struct device *ctrldev;
bf83490e	312	struct caam_drv_private *priv;
d239b10d	313	u32 rng_inst;
ce572085	314	int err;
35af6403 RG	315
	316	dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec-v4.0");
	317	if (!dev_node) {
	318	dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec4.0");
	319	if (!dev_node)
	320	return -ENODEV;
	321	}
	322
	323	pdev = of_find_device_by_node(dev_node);
	324	if (!pdev) {
	325	of_node_put(dev_node);
	326	return -ENODEV;
	327	}
	328
	329	ctrldev = &pdev->dev;
	330	priv = dev_get_drvdata(ctrldev);
	331	of_node_put(dev_node);
	332
	333	/*
	334	* If priv is NULL, it's probably because the caam driver wasn't
	335	* properly initialized (e.g. RNG4 init failed). Thus, bail out here.
	336	*/
	337	if (!priv)
	338	return -ENODEV;
e24f7c9e	339
bf83490e	340	/* Check for an instantiated RNG before registration */
d239b10d HG	341	if (priv->era < 10)
	342	rng_inst = (rd_reg32(&priv->ctrl->perfmon.cha_num_ls) &
	343	CHA_ID_LS_RNG_MASK) >> CHA_ID_LS_RNG_SHIFT;
	344	else
	345	rng_inst = rd_reg32(&priv->ctrl->vreg.rng) & CHA_VER_NUM_MASK;
	346
	347	if (!rng_inst)
bf83490e VM	348	return -ENODEV;
bf83490e VM	349
cfc6f11b RG	350	dev = caam_jr_alloc();
	351	if (IS_ERR(dev)) {
	352	pr_err("Job Ring Device allocation for transform failed\n");
	353	return PTR_ERR(dev);
	354	}
c530e341	355	rng_ctx = kmalloc(sizeof(*rng_ctx), GFP_DMA \| GFP_KERNEL);
ac8ad307 FE	356	if (!rng_ctx) {
	357	err = -ENOMEM;
	358	goto free_caam_alloc;
	359	}
ce572085 HG	360	err = caam_init_rng(rng_ctx, dev);
ce572085 HG	361	if (err)
ac8ad307	362	goto free_rng_ctx;
e24f7c9e	363
cfc6f11b	364	dev_info(dev, "registering rng-caam\n");
e24f7c9e	365	return hwrng_register(&caam_rng);
ac8ad307 FE	366
	367	free_rng_ctx:
	368	kfree(rng_ctx);
	369	free_caam_alloc:
	370	caam_jr_free(dev);
	371	return err;
e24f7c9e YK	372	}
	373
	374	module_init(caam_rng_init);
	375	module_exit(caam_rng_exit);
	376
	377	MODULE_LICENSE("GPL");
	378	MODULE_DESCRIPTION("FSL CAAM support for hw_random API");
	379	MODULE_AUTHOR("Freescale Semiconductor - NMG");