1 files changed, 311 insertions, 0 deletions
diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c
new file mode 100644
index 0000000000..b3d14a7f4d
--- /dev/null
+++ b/drivers/crypto/caam/caamrng.c
@@ -0,0 +1,311 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * caam - Freescale FSL CAAM support for hw_random
+ *
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2018-2019, 2023 NXP
+ *
+ * Based on caamalg.c crypto API driver.
+ *
+ */
+
+#include <linux/hw_random.h>
+#include <linux/completion.h>
+#include <linux/atomic.h>
+#include <linux/dma-mapping.h>
+#include <linux/kernel.h>
+#include <linux/kfifo.h>
+
+#include "compat.h"
+
+#include "regs.h"
+#include "intern.h"
+#include "desc_constr.h"
+#include "jr.h"
+#include "error.h"
+
+#define CAAM_RNG_MAX_FIFO_STORE_SIZE	16
+
+/*
+ * Length of used descriptors, see caam_init_desc()
+ */
+#define CAAM_RNG_DESC_LEN (CAAM_CMD_SZ +				\
+			   CAAM_CMD_SZ +				\
+			   CAAM_CMD_SZ + CAAM_PTR_SZ_MAX)
+
+/* rng per-device context */
+struct caam_rng_ctx {
+	struct hwrng rng;
+	struct device *jrdev;
+	struct device *ctrldev;
+	void *desc_async;
+	void *desc_sync;
+	struct work_struct worker;
+	struct kfifo fifo;
+};
+
+struct caam_rng_job_ctx {
+	struct completion *done;
+	int *err;
+};
+
+static struct caam_rng_ctx *to_caam_rng_ctx(struct hwrng *r)
+{
+	return (struct caam_rng_ctx *)r->priv;
+}
+
+static void caam_rng_done(struct device *jrdev, u32 *desc, u32 err,
+			  void *context)
+{
+	struct caam_rng_job_ctx *jctx = context;
+
+	if (err)
+		*jctx->err = caam_jr_strstatus(jrdev, err);
+
+	complete(jctx->done);
+}
+
+static u32 *caam_init_desc(u32 *desc, dma_addr_t dst_dma)
+{
+	init_job_desc(desc, 0);	/* + 1 cmd_sz */
+	/* Generate random bytes: + 1 cmd_sz */
+	append_operation(desc, OP_ALG_ALGSEL_RNG | OP_TYPE_CLASS1_ALG |
+			 OP_ALG_PR_ON);
+	/* Store bytes: + 1 cmd_sz + caam_ptr_sz  */
+	append_fifo_store(desc, dst_dma,
+			  CAAM_RNG_MAX_FIFO_STORE_SIZE, FIFOST_TYPE_RNGSTORE);
+
+	print_hex_dump_debug("rng job desc@: ", DUMP_PREFIX_ADDRESS,
+			     16, 4, desc, desc_bytes(desc), 1);
+
+	return desc;
+}
+
+static int caam_rng_read_one(struct device *jrdev,
+			     void *dst, int len,
+			     void *desc,
+			     struct completion *done)
+{
+	dma_addr_t dst_dma;
+	int err, ret = 0;
+	struct caam_rng_job_ctx jctx = {
+		.done = done,
+		.err  = &ret,
+	};
+
+	len = CAAM_RNG_MAX_FIFO_STORE_SIZE;
+
+	dst_dma = dma_map_single(jrdev, dst, len, DMA_FROM_DEVICE);
+	if (dma_mapping_error(jrdev, dst_dma)) {
+		dev_err(jrdev, "unable to map destination memory\n");
+		return -ENOMEM;
+	}
+
+	init_completion(done);
+	err = caam_jr_enqueue(jrdev,
+			      caam_init_desc(desc, dst_dma),
+			      caam_rng_done, &jctx);
+	if (err == -EINPROGRESS) {
+		wait_for_completion(done);
+		err = 0;
+	}
+
+	dma_unmap_single(jrdev, dst_dma, len, DMA_FROM_DEVICE);
+
+	return err ?: (ret ?: len);
+}
+
+static void caam_rng_fill_async(struct caam_rng_ctx *ctx)
+{
+	struct scatterlist sg[1];
+	struct completion done;
+	int len, nents;
+
+	sg_init_table(sg, ARRAY_SIZE(sg));
+	nents = kfifo_dma_in_prepare(&ctx->fifo, sg, ARRAY_SIZE(sg),
+				     CAAM_RNG_MAX_FIFO_STORE_SIZE);
+	if (!nents)
+		return;
+
+	len = caam_rng_read_one(ctx->jrdev, sg_virt(&sg[0]),
+				sg[0].length,
+				ctx->desc_async,
+				&done);
+	if (len < 0)
+		return;
+
+	kfifo_dma_in_finish(&ctx->fifo, len);
+}
+
+static void caam_rng_worker(struct work_struct *work)
+{
+	struct caam_rng_ctx *ctx = container_of(work, struct caam_rng_ctx,
+						worker);
+	caam_rng_fill_async(ctx);
+}
+
+static int caam_read(struct hwrng *rng, void *dst, size_t max, bool wait)
+{
+	struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
+	int out;
+
+	if (wait) {
+		struct completion done;
+
+		return caam_rng_read_one(ctx->jrdev, dst, max,
+					 ctx->desc_sync, &done);
+	}
+
+	out = kfifo_out(&ctx->fifo, dst, max);
+	if (kfifo_is_empty(&ctx->fifo))
+		schedule_work(&ctx->worker);
+
+	return out;
+}
+
+static void caam_cleanup(struct hwrng *rng)
+{
+	struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
+
+	flush_work(&ctx->worker);
+	caam_jr_free(ctx->jrdev);
+	kfifo_free(&ctx->fifo);
+}
+
+#ifdef CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_TEST
+static inline void test_len(struct hwrng *rng, size_t len, bool wait)
+{
+	u8 *buf;
+	int read_len;
+	struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
+	struct device *dev = ctx->ctrldev;
+
+	buf = kcalloc(CAAM_RNG_MAX_FIFO_STORE_SIZE, sizeof(u8), GFP_KERNEL);
+
+	while (len > 0) {
+		read_len = rng->read(rng, buf, len, wait);
+
+		if (read_len < 0 || (read_len == 0 && wait)) {
+			dev_err(dev, "RNG Read FAILED received %d bytes\n",
+				read_len);
+			kfree(buf);
+			return;
+		}
+
+		print_hex_dump_debug("random bytes@: ",
+			DUMP_PREFIX_ADDRESS, 16, 4,
+			buf, read_len, 1);
+
+		len = len - read_len;
+	}
+
+	kfree(buf);
+}
+
+static inline void test_mode_once(struct hwrng *rng, bool wait)
+{
+	test_len(rng, 32, wait);
+	test_len(rng, 64, wait);
+	test_len(rng, 128, wait);
+}
+
+static void self_test(struct hwrng *rng)
+{
+	pr_info("Executing RNG SELF-TEST with wait\n");
+	test_mode_once(rng, true);
+}
+#endif
+
+static int caam_init(struct hwrng *rng)
+{
+	struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
+	int err;
+
+	ctx->desc_sync = devm_kzalloc(ctx->ctrldev, CAAM_RNG_DESC_LEN,
+				      GFP_KERNEL);
+	if (!ctx->desc_sync)
+		return -ENOMEM;
+
+	ctx->desc_async = devm_kzalloc(ctx->ctrldev, CAAM_RNG_DESC_LEN,
+				       GFP_KERNEL);
+	if (!ctx->desc_async)
+		return -ENOMEM;
+
+	if (kfifo_alloc(&ctx->fifo, ALIGN(CAAM_RNG_MAX_FIFO_STORE_SIZE,
+					  dma_get_cache_alignment()),
+			GFP_KERNEL))
+		return -ENOMEM;
+
+	INIT_WORK(&ctx->worker, caam_rng_worker);
+
+	ctx->jrdev = caam_jr_alloc();
+	err = PTR_ERR_OR_ZERO(ctx->jrdev);
+	if (err) {
+		kfifo_free(&ctx->fifo);
+		pr_err("Job Ring Device allocation for transform failed\n");
+		return err;
+	}
+
+	/*
+	 * Fill async buffer to have early randomness data for
+	 * hw_random
+	 */
+	caam_rng_fill_async(ctx);
+
+	return 0;
+}
+
+int caam_rng_init(struct device *ctrldev);
+
+void caam_rng_exit(struct device *ctrldev)
+{
+	devres_release_group(ctrldev, caam_rng_init);
+}
+
+int caam_rng_init(struct device *ctrldev)
+{
+	struct caam_rng_ctx *ctx;
+	u32 rng_inst;
+	struct caam_drv_private *priv = dev_get_drvdata(ctrldev);
+	int ret;
+
+	/* Check for an instantiated RNG before registration */
+	if (priv->era < 10)
+		rng_inst = (rd_reg32(&priv->jr[0]->perfmon.cha_num_ls) &
+			    CHA_ID_LS_RNG_MASK) >> CHA_ID_LS_RNG_SHIFT;
+	else
+		rng_inst = rd_reg32(&priv->jr[0]->vreg.rng) & CHA_VER_NUM_MASK;
+
+	if (!rng_inst)
+		return 0;
+
+	if (!devres_open_group(ctrldev, caam_rng_init, GFP_KERNEL))
+		return -ENOMEM;
+
+	ctx = devm_kzalloc(ctrldev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->ctrldev = ctrldev;
+
+	ctx->rng.name    = "rng-caam";
+	ctx->rng.init    = caam_init;
+	ctx->rng.cleanup = caam_cleanup;
+	ctx->rng.read    = caam_read;
+	ctx->rng.priv    = (unsigned long)ctx;
+
+	dev_info(ctrldev, "registering rng-caam\n");
+
+	ret = devm_hwrng_register(ctrldev, &ctx->rng);
+	if (ret) {
+		caam_rng_exit(ctrldev);
+		return ret;
+	}
+
+#ifdef CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_TEST
+	self_test(&ctx->rng);
+#endif
+
+	devres_close_group(ctrldev, caam_rng_init);
+	return 0;
+}