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2024-05-13 9d77db3c730780c8ef5ccd4b66403ff5675cfe4e 
 kernel/drivers/crypto/caam/caamrng.c
....@@ -1,39 +1,18 @@
1
+// SPDX-License-Identifier: GPL-2.0+
12 /*
23  * caam - Freescale FSL CAAM support for hw_random
34  *
45  * Copyright 2011 Freescale Semiconductor, Inc.
6
+ * Copyright 2018-2019 NXP
57  *
68  * Based on caamalg.c crypto API driver.
79  *
8
- * relationship between job descriptors to shared descriptors:
9
- *
10
- * ---------------                     --------------
11
- * | JobDesc #0  |-------------------->| ShareDesc  |
12
- * | *(buffer 0) |      |------------->| (generate) |
13
- * ---------------      |              | (move)     |
14
- *                      |              | (store)    |
15
- * ---------------      |              --------------
16
- * | JobDesc #1  |------|
17
- * | *(buffer 1) |
18
- * ---------------
19
- *
20
- * A job desc looks like this:
21
- *
22
- * ---------------------
23
- * | Header            |
24
- * | ShareDesc Pointer |
25
- * | SEQ_OUT_PTR       |
26
- * | (output buffer)   |
27
- * ---------------------
28
- *
29
- * The SharedDesc never changes, and each job descriptor points to one of two
30
- * buffers for each device, from which the data will be copied into the
31
- * requested destination
3210  */
3311 
3412 #include <linux/hw_random.h>
3513 #include <linux/completion.h>
3614 #include <linux/atomic.h>
15
+#include <linux/kfifo.h>
3716 
3817 #include "compat.h"
3918 
....@@ -43,331 +22,240 @@
4322 #include "jr.h"
4423 #include "error.h"
4524 
25
+#define CAAM_RNG_MAX_FIFO_STORE_SIZE	16
26
+
4627 /*
47
- * Maximum buffer size: maximum number of random, cache-aligned bytes that
48
- * will be generated and moved to seq out ptr (extlen not allowed)
28
+ * Length of used descriptors, see caam_init_desc()
4929  */
50
-#define RN_BUF_SIZE			(0xffff / L1_CACHE_BYTES * \
51
-					 L1_CACHE_BYTES)
52
-
53
-/* length of descriptors */
54
-#define DESC_JOB_O_LEN			(CAAM_CMD_SZ * 2 + CAAM_PTR_SZ * 2)
55
-#define DESC_RNG_LEN			(3 * CAAM_CMD_SZ)
56
-
57
-/* Buffer, its dma address and lock */
58
-struct buf_data {
59
-	u8 buf[RN_BUF_SIZE] ____cacheline_aligned;
60
-	dma_addr_t addr;
61
-	struct completion filled;
62
-	u32 hw_desc[DESC_JOB_O_LEN];
63
-#define BUF_NOT_EMPTY 0
64
-#define BUF_EMPTY 1
65
-#define BUF_PENDING 2  /* Empty, but with job pending --don't submit another */
66
-	atomic_t empty;
67
-};
30
+#define CAAM_RNG_DESC_LEN (CAAM_CMD_SZ +				\
31
+			   CAAM_CMD_SZ +				\
32
+			   CAAM_CMD_SZ + CAAM_PTR_SZ_MAX)
6833 
6934 /* rng per-device context */
7035 struct caam_rng_ctx {
36
+	struct hwrng rng;
7137 	struct device *jrdev;
72
-	dma_addr_t sh_desc_dma;
73
-	u32 sh_desc[DESC_RNG_LEN];
74
-	unsigned int cur_buf_idx;
75
-	int current_buf;
76
-	struct buf_data bufs[2];
38
+	struct device *ctrldev;
39
+	void *desc_async;
40
+	void *desc_sync;
41
+	struct work_struct worker;
42
+	struct kfifo fifo;
7743 };
7844 
79
-static struct caam_rng_ctx *rng_ctx;
45
+struct caam_rng_job_ctx {
46
+	struct completion *done;
47
+	int *err;
48
+};
8049 
81
-static inline void rng_unmap_buf(struct device *jrdev, struct buf_data *bd)
50
+static struct caam_rng_ctx *to_caam_rng_ctx(struct hwrng *r)
8251 {
83
-	if (bd->addr)
84
-		dma_unmap_single(jrdev, bd->addr, RN_BUF_SIZE,
85
-				 DMA_FROM_DEVICE);
52
+	return (struct caam_rng_ctx *)r->priv;
8653 }
8754 
88
-static inline void rng_unmap_ctx(struct caam_rng_ctx *ctx)
55
+static void caam_rng_done(struct device *jrdev, u32 *desc, u32 err,
56
+			  void *context)
8957 {
90
-	struct device *jrdev = ctx->jrdev;
91
-
92
-	if (ctx->sh_desc_dma)
93
-		dma_unmap_single(jrdev, ctx->sh_desc_dma,
94
-				 desc_bytes(ctx->sh_desc), DMA_TO_DEVICE);
95
-	rng_unmap_buf(jrdev, &ctx->bufs[0]);
96
-	rng_unmap_buf(jrdev, &ctx->bufs[1]);
97
-}
98
-
99
-static void rng_done(struct device *jrdev, u32 *desc, u32 err, void *context)
100
-{
101
-	struct buf_data *bd;
102
-
103
-	bd = container_of(desc, struct buf_data, hw_desc[0]);
58
+	struct caam_rng_job_ctx *jctx = context;
10459 
10560 	if (err)
106
-		caam_jr_strstatus(jrdev, err);
61
+		*jctx->err = caam_jr_strstatus(jrdev, err);
10762 
108
-	atomic_set(&bd->empty, BUF_NOT_EMPTY);
109
-	complete(&bd->filled);
110
-
111
-	/* Buffer refilled, invalidate cache */
112
-	dma_sync_single_for_cpu(jrdev, bd->addr, RN_BUF_SIZE, DMA_FROM_DEVICE);
113
-
114
-#ifdef DEBUG
115
-	print_hex_dump(KERN_ERR, "rng refreshed buf@: ",
116
-		       DUMP_PREFIX_ADDRESS, 16, 4, bd->buf, RN_BUF_SIZE, 1);
117
-#endif
63
+	complete(jctx->done);
11864 }
11965 
120
-static inline int submit_job(struct caam_rng_ctx *ctx, int to_current)
66
+static u32 *caam_init_desc(u32 *desc, dma_addr_t dst_dma)
12167 {
122
-	struct buf_data *bd = &ctx->bufs[!(to_current ^ ctx->current_buf)];
123
-	struct device *jrdev = ctx->jrdev;
124
-	u32 *desc = bd->hw_desc;
125
-	int err;
68
+	init_job_desc(desc, 0);	/* + 1 cmd_sz */
69
+	/* Generate random bytes: + 1 cmd_sz */
70
+	append_operation(desc, OP_ALG_ALGSEL_RNG | OP_TYPE_CLASS1_ALG |
71
+			 OP_ALG_PR_ON);
72
+	/* Store bytes: + 1 cmd_sz + caam_ptr_sz  */
73
+	append_fifo_store(desc, dst_dma,
74
+			  CAAM_RNG_MAX_FIFO_STORE_SIZE, FIFOST_TYPE_RNGSTORE);
12675 
127
-	dev_dbg(jrdev, "submitting job %d\n", !(to_current ^ ctx->current_buf));
128
-	init_completion(&bd->filled);
129
-	err = caam_jr_enqueue(jrdev, desc, rng_done, ctx);
130
-	if (err)
131
-		complete(&bd->filled); /* don't wait on failed job*/
132
-	else
133
-		atomic_inc(&bd->empty); /* note if pending */
76
+	print_hex_dump_debug("rng job desc@: ", DUMP_PREFIX_ADDRESS,
77
+			     16, 4, desc, desc_bytes(desc), 1);
13478 
135
-	return err;
79
+	return desc;
13680 }
13781 
138
-static int caam_read(struct hwrng *rng, void *data, size_t max, bool wait)
82
+static int caam_rng_read_one(struct device *jrdev,
83
+			     void *dst, int len,
84
+			     void *desc,
85
+			     struct completion *done)
13986 {
140
-	struct caam_rng_ctx *ctx = rng_ctx;
141
-	struct buf_data *bd = &ctx->bufs[ctx->current_buf];
142
-	int next_buf_idx, copied_idx;
143
-	int err;
87
+	dma_addr_t dst_dma;
88
+	int err, ret = 0;
89
+	struct caam_rng_job_ctx jctx = {
90
+		.done = done,
91
+		.err  = &ret,
92
+	};
14493 
145
-	if (atomic_read(&bd->empty)) {
146
-		/* try to submit job if there wasn't one */
147
-		if (atomic_read(&bd->empty) == BUF_EMPTY) {
148
-			err = submit_job(ctx, 1);
149
-			/* if can't submit job, can't even wait */
150
-			if (err)
151
-				return 0;
152
-		}
153
-		/* no immediate data, so exit if not waiting */
154
-		if (!wait)
155
-			return 0;
94
+	len = CAAM_RNG_MAX_FIFO_STORE_SIZE;
15695 
157
-		/* waiting for pending job */
158
-		if (atomic_read(&bd->empty))
159
-			wait_for_completion(&bd->filled);
160
-	}
161
-
162
-	next_buf_idx = ctx->cur_buf_idx + max;
163
-	dev_dbg(ctx->jrdev, "%s: start reading at buffer %d, idx %d\n",
164
-		 __func__, ctx->current_buf, ctx->cur_buf_idx);
165
-
166
-	/* if enough data in current buffer */
167
-	if (next_buf_idx < RN_BUF_SIZE) {
168
-		memcpy(data, bd->buf + ctx->cur_buf_idx, max);
169
-		ctx->cur_buf_idx = next_buf_idx;
170
-		return max;
171
-	}
172
-
173
-	/* else, copy what's left... */
174
-	copied_idx = RN_BUF_SIZE - ctx->cur_buf_idx;
175
-	memcpy(data, bd->buf + ctx->cur_buf_idx, copied_idx);
176
-	ctx->cur_buf_idx = 0;
177
-	atomic_set(&bd->empty, BUF_EMPTY);
178
-
179
-	/* ...refill... */
180
-	submit_job(ctx, 1);
181
-
182
-	/* and use next buffer */
183
-	ctx->current_buf = !ctx->current_buf;
184
-	dev_dbg(ctx->jrdev, "switched to buffer %d\n", ctx->current_buf);
185
-
186
-	/* since there already is some data read, don't wait */
187
-	return copied_idx + caam_read(rng, data + copied_idx,
188
-				      max - copied_idx, false);
189
-}
190
-
191
-static inline int rng_create_sh_desc(struct caam_rng_ctx *ctx)
192
-{
193
-	struct device *jrdev = ctx->jrdev;
194
-	u32 *desc = ctx->sh_desc;
195
-
196
-	init_sh_desc(desc, HDR_SHARE_SERIAL);
197
-
198
-	/* Generate random bytes */
199
-	append_operation(desc, OP_ALG_ALGSEL_RNG | OP_TYPE_CLASS1_ALG);
200
-
201
-	/* Store bytes */
202
-	append_seq_fifo_store(desc, RN_BUF_SIZE, FIFOST_TYPE_RNGSTORE);
203
-
204
-	ctx->sh_desc_dma = dma_map_single(jrdev, desc, desc_bytes(desc),
205
-					  DMA_TO_DEVICE);
206
-	if (dma_mapping_error(jrdev, ctx->sh_desc_dma)) {
207
-		dev_err(jrdev, "unable to map shared descriptor\n");
208
-		return -ENOMEM;
209
-	}
210
-#ifdef DEBUG
211
-	print_hex_dump(KERN_ERR, "rng shdesc@: ", DUMP_PREFIX_ADDRESS, 16, 4,
212
-		       desc, desc_bytes(desc), 1);
213
-#endif
214
-	return 0;
215
-}
216
-
217
-static inline int rng_create_job_desc(struct caam_rng_ctx *ctx, int buf_id)
218
-{
219
-	struct device *jrdev = ctx->jrdev;
220
-	struct buf_data *bd = &ctx->bufs[buf_id];
221
-	u32 *desc = bd->hw_desc;
222
-	int sh_len = desc_len(ctx->sh_desc);
223
-
224
-	init_job_desc_shared(desc, ctx->sh_desc_dma, sh_len, HDR_SHARE_DEFER |
225
-			     HDR_REVERSE);
226
-
227
-	bd->addr = dma_map_single(jrdev, bd->buf, RN_BUF_SIZE, DMA_FROM_DEVICE);
228
-	if (dma_mapping_error(jrdev, bd->addr)) {
229
-		dev_err(jrdev, "unable to map dst\n");
96
+	dst_dma = dma_map_single(jrdev, dst, len, DMA_FROM_DEVICE);
97
+	if (dma_mapping_error(jrdev, dst_dma)) {
98
+		dev_err(jrdev, "unable to map destination memory\n");
23099 		return -ENOMEM;
231100 	}
232101 
233
-	append_seq_out_ptr_intlen(desc, bd->addr, RN_BUF_SIZE, 0);
234
-#ifdef DEBUG
235
-	print_hex_dump(KERN_ERR, "rng job desc@: ", DUMP_PREFIX_ADDRESS, 16, 4,
236
-		       desc, desc_bytes(desc), 1);
237
-#endif
238
-	return 0;
102
+	init_completion(done);
103
+	err = caam_jr_enqueue(jrdev,
104
+			      caam_init_desc(desc, dst_dma),
105
+			      caam_rng_done, &jctx);
106
+	if (err == -EINPROGRESS) {
107
+		wait_for_completion(done);
108
+		err = 0;
109
+	}
110
+
111
+	dma_unmap_single(jrdev, dst_dma, len, DMA_FROM_DEVICE);
112
+
113
+	return err ?: (ret ?: len);
114
+}
115
+
116
+static void caam_rng_fill_async(struct caam_rng_ctx *ctx)
117
+{
118
+	struct scatterlist sg[1];
119
+	struct completion done;
120
+	int len, nents;
121
+
122
+	sg_init_table(sg, ARRAY_SIZE(sg));
123
+	nents = kfifo_dma_in_prepare(&ctx->fifo, sg, ARRAY_SIZE(sg),
124
+				     CAAM_RNG_MAX_FIFO_STORE_SIZE);
125
+	if (!nents)
126
+		return;
127
+
128
+	len = caam_rng_read_one(ctx->jrdev, sg_virt(&sg[0]),
129
+				sg[0].length,
130
+				ctx->desc_async,
131
+				&done);
132
+	if (len < 0)
133
+		return;
134
+
135
+	kfifo_dma_in_finish(&ctx->fifo, len);
136
+}
137
+
138
+static void caam_rng_worker(struct work_struct *work)
139
+{
140
+	struct caam_rng_ctx *ctx = container_of(work, struct caam_rng_ctx,
141
+						worker);
142
+	caam_rng_fill_async(ctx);
143
+}
144
+
145
+static int caam_read(struct hwrng *rng, void *dst, size_t max, bool wait)
146
+{
147
+	struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
148
+	int out;
149
+
150
+	if (wait) {
151
+		struct completion done;
152
+
153
+		return caam_rng_read_one(ctx->jrdev, dst, max,
154
+					 ctx->desc_sync, &done);
155
+	}
156
+
157
+	out = kfifo_out(&ctx->fifo, dst, max);
158
+	if (kfifo_is_empty(&ctx->fifo))
159
+		schedule_work(&ctx->worker);
160
+
161
+	return out;
239162 }
240163 
241164 static void caam_cleanup(struct hwrng *rng)
242165 {
243
-	int i;
244
-	struct buf_data *bd;
166
+	struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
245167 
246
-	for (i = 0; i < 2; i++) {
247
-		bd = &rng_ctx->bufs[i];
248
-		if (atomic_read(&bd->empty) == BUF_PENDING)
249
-			wait_for_completion(&bd->filled);
250
-	}
251
-
252
-	rng_unmap_ctx(rng_ctx);
168
+	flush_work(&ctx->worker);
169
+	caam_jr_free(ctx->jrdev);
170
+	kfifo_free(&ctx->fifo);
253171 }
254172 
255
-static int caam_init_buf(struct caam_rng_ctx *ctx, int buf_id)
173
+static int caam_init(struct hwrng *rng)
256174 {
257
-	struct buf_data *bd = &ctx->bufs[buf_id];
175
+	struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
258176 	int err;
259177 
260
-	err = rng_create_job_desc(ctx, buf_id);
261
-	if (err)
262
-		return err;
178
+	ctx->desc_sync = devm_kzalloc(ctx->ctrldev, CAAM_RNG_DESC_LEN,
179
+				      GFP_DMA | GFP_KERNEL);
180
+	if (!ctx->desc_sync)
181
+		return -ENOMEM;
263182 
264
-	atomic_set(&bd->empty, BUF_EMPTY);
265
-	submit_job(ctx, buf_id == ctx->current_buf);
266
-	wait_for_completion(&bd->filled);
183
+	ctx->desc_async = devm_kzalloc(ctx->ctrldev, CAAM_RNG_DESC_LEN,
184
+				       GFP_DMA | GFP_KERNEL);
185
+	if (!ctx->desc_async)
186
+		return -ENOMEM;
187
+
188
+	if (kfifo_alloc(&ctx->fifo, CAAM_RNG_MAX_FIFO_STORE_SIZE,
189
+			GFP_DMA | GFP_KERNEL))
190
+		return -ENOMEM;
191
+
192
+	INIT_WORK(&ctx->worker, caam_rng_worker);
193
+
194
+	ctx->jrdev = caam_jr_alloc();
195
+	err = PTR_ERR_OR_ZERO(ctx->jrdev);
196
+	if (err) {
197
+		kfifo_free(&ctx->fifo);
198
+		pr_err("Job Ring Device allocation for transform failed\n");
199
+		return err;
200
+	}
201
+
202
+	/*
203
+	 * Fill async buffer to have early randomness data for
204
+	 * hw_random
205
+	 */
206
+	caam_rng_fill_async(ctx);
267207 
268208 	return 0;
269209 }
270210 
271
-static int caam_init_rng(struct caam_rng_ctx *ctx, struct device *jrdev)
211
+int caam_rng_init(struct device *ctrldev);
212
+
213
+void caam_rng_exit(struct device *ctrldev)
272214 {
273
-	int err;
274
-
275
-	ctx->jrdev = jrdev;
276
-
277
-	err = rng_create_sh_desc(ctx);
278
-	if (err)
279
-		return err;
280
-
281
-	ctx->current_buf = 0;
282
-	ctx->cur_buf_idx = 0;
283
-
284
-	err = caam_init_buf(ctx, 0);
285
-	if (err)
286
-		return err;
287
-
288
-	return caam_init_buf(ctx, 1);
215
+	devres_release_group(ctrldev, caam_rng_init);
289216 }
290217 
291
-static struct hwrng caam_rng = {
292
-	.name		= "rng-caam",
293
-	.cleanup	= caam_cleanup,
294
-	.read		= caam_read,
295
-};
296
-
297
-static void __exit caam_rng_exit(void)
218
+int caam_rng_init(struct device *ctrldev)
298219 {
299
-	caam_jr_free(rng_ctx->jrdev);
300
-	hwrng_unregister(&caam_rng);
301
-	kfree(rng_ctx);
302
-}
303
-
304
-static int __init caam_rng_init(void)
305
-{
306
-	struct device *dev;
307
-	struct device_node *dev_node;
308
-	struct platform_device *pdev;
309
-	struct device *ctrldev;
310
-	struct caam_drv_private *priv;
311
-	int err;
312
-
313
-	dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec-v4.0");
314
-	if (!dev_node) {
315
-		dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec4.0");
316
-		if (!dev_node)
317
-			return -ENODEV;
318
-	}
319
-
320
-	pdev = of_find_device_by_node(dev_node);
321
-	if (!pdev) {
322
-		of_node_put(dev_node);
323
-		return -ENODEV;
324
-	}
325
-
326
-	ctrldev = &pdev->dev;
327
-	priv = dev_get_drvdata(ctrldev);
328
-	of_node_put(dev_node);
329
-
330
-	/*
331
-	 * If priv is NULL, it's probably because the caam driver wasn't
332
-	 * properly initialized (e.g. RNG4 init failed). Thus, bail out here.
333
-	 */
334
-	if (!priv)
335
-		return -ENODEV;
220
+	struct caam_rng_ctx *ctx;
221
+	u32 rng_inst;
222
+	struct caam_drv_private *priv = dev_get_drvdata(ctrldev);
223
+	int ret;
336224 
337225 	/* Check for an instantiated RNG before registration */
338
-	if (!(rd_reg32(&priv->ctrl->perfmon.cha_num_ls) & CHA_ID_LS_RNG_MASK))
339
-		return -ENODEV;
226
+	if (priv->era < 10)
227
+		rng_inst = (rd_reg32(&priv->ctrl->perfmon.cha_num_ls) &
228
+			    CHA_ID_LS_RNG_MASK) >> CHA_ID_LS_RNG_SHIFT;
229
+	else
230
+		rng_inst = rd_reg32(&priv->ctrl->vreg.rng) & CHA_VER_NUM_MASK;
340231 
341
-	dev = caam_jr_alloc();
342
-	if (IS_ERR(dev)) {
343
-		pr_err("Job Ring Device allocation for transform failed\n");
344
-		return PTR_ERR(dev);
232
+	if (!rng_inst)
233
+		return 0;
234
+
235
+	if (!devres_open_group(ctrldev, caam_rng_init, GFP_KERNEL))
236
+		return -ENOMEM;
237
+
238
+	ctx = devm_kzalloc(ctrldev, sizeof(*ctx), GFP_KERNEL);
239
+	if (!ctx)
240
+		return -ENOMEM;
241
+
242
+	ctx->ctrldev = ctrldev;
243
+
244
+	ctx->rng.name    = "rng-caam";
245
+	ctx->rng.init    = caam_init;
246
+	ctx->rng.cleanup = caam_cleanup;
247
+	ctx->rng.read    = caam_read;
248
+	ctx->rng.priv    = (unsigned long)ctx;
249
+	ctx->rng.quality = 1024;
250
+
251
+	dev_info(ctrldev, "registering rng-caam\n");
252
+
253
+	ret = devm_hwrng_register(ctrldev, &ctx->rng);
254
+	if (ret) {
255
+		caam_rng_exit(ctrldev);
256
+		return ret;
345257 	}
346
-	rng_ctx = kmalloc(sizeof(*rng_ctx), GFP_DMA | GFP_KERNEL);
347
-	if (!rng_ctx) {
348
-		err = -ENOMEM;
349
-		goto free_caam_alloc;
350
-	}
351
-	err = caam_init_rng(rng_ctx, dev);
352
-	if (err)
353
-		goto free_rng_ctx;
354258 
355
-	dev_info(dev, "registering rng-caam\n");
356
-
357
-	err = hwrng_register(&caam_rng);
358
-	if (!err)
359
-		return err;
360
-
361
-free_rng_ctx:
362
-	kfree(rng_ctx);
363
-free_caam_alloc:
364
-	caam_jr_free(dev);
365
-	return err;
259
+	devres_close_group(ctrldev, caam_rng_init);
260
+	return 0;
366261 }
367
-
368
-module_init(caam_rng_init);
369
-module_exit(caam_rng_exit);
370
-
371
-MODULE_LICENSE("GPL");
372
-MODULE_DESCRIPTION("FSL CAAM support for hw_random API");
373
-MODULE_AUTHOR("Freescale Semiconductor - NMG");