xref: /openbmc/linux/drivers/crypto/caam/key_gen.c (revision 293d5b43)
1 /*
2  * CAAM/SEC 4.x functions for handling key-generation jobs
3  *
4  * Copyright 2008-2011 Freescale Semiconductor, Inc.
5  *
6  */
7 #include "compat.h"
8 #include "jr.h"
9 #include "error.h"
10 #include "desc_constr.h"
11 #include "key_gen.h"
12 
13 void split_key_done(struct device *dev, u32 *desc, u32 err,
14 			   void *context)
15 {
16 	struct split_key_result *res = context;
17 
18 #ifdef DEBUG
19 	dev_err(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
20 #endif
21 
22 	if (err)
23 		caam_jr_strstatus(dev, err);
24 
25 	res->err = err;
26 
27 	complete(&res->completion);
28 }
29 EXPORT_SYMBOL(split_key_done);
30 /*
31 get a split ipad/opad key
32 
33 Split key generation-----------------------------------------------
34 
35 [00] 0xb0810008    jobdesc: stidx=1 share=never len=8
36 [01] 0x04000014        key: class2->keyreg len=20
37 			@0xffe01000
38 [03] 0x84410014  operation: cls2-op sha1 hmac init dec
39 [04] 0x24940000     fifold: class2 msgdata-last2 len=0 imm
40 [05] 0xa4000001       jump: class2 local all ->1 [06]
41 [06] 0x64260028    fifostr: class2 mdsplit-jdk len=40
42 			@0xffe04000
43 */
44 int gen_split_key(struct device *jrdev, u8 *key_out, int split_key_len,
45 		  int split_key_pad_len, const u8 *key_in, u32 keylen,
46 		  u32 alg_op)
47 {
48 	u32 *desc;
49 	struct split_key_result result;
50 	dma_addr_t dma_addr_in, dma_addr_out;
51 	int ret = -ENOMEM;
52 
53 	desc = kmalloc(CAAM_CMD_SZ * 6 + CAAM_PTR_SZ * 2, GFP_KERNEL | GFP_DMA);
54 	if (!desc) {
55 		dev_err(jrdev, "unable to allocate key input memory\n");
56 		return ret;
57 	}
58 
59 	dma_addr_in = dma_map_single(jrdev, (void *)key_in, keylen,
60 				     DMA_TO_DEVICE);
61 	if (dma_mapping_error(jrdev, dma_addr_in)) {
62 		dev_err(jrdev, "unable to map key input memory\n");
63 		goto out_free;
64 	}
65 
66 	dma_addr_out = dma_map_single(jrdev, key_out, split_key_pad_len,
67 				      DMA_FROM_DEVICE);
68 	if (dma_mapping_error(jrdev, dma_addr_out)) {
69 		dev_err(jrdev, "unable to map key output memory\n");
70 		goto out_unmap_in;
71 	}
72 
73 	init_job_desc(desc, 0);
74 	append_key(desc, dma_addr_in, keylen, CLASS_2 | KEY_DEST_CLASS_REG);
75 
76 	/* Sets MDHA up into an HMAC-INIT */
77 	append_operation(desc, alg_op | OP_ALG_DECRYPT | OP_ALG_AS_INIT);
78 
79 	/*
80 	 * do a FIFO_LOAD of zero, this will trigger the internal key expansion
81 	 * into both pads inside MDHA
82 	 */
83 	append_fifo_load_as_imm(desc, NULL, 0, LDST_CLASS_2_CCB |
84 				FIFOLD_TYPE_MSG | FIFOLD_TYPE_LAST2);
85 
86 	/*
87 	 * FIFO_STORE with the explicit split-key content store
88 	 * (0x26 output type)
89 	 */
90 	append_fifo_store(desc, dma_addr_out, split_key_len,
91 			  LDST_CLASS_2_CCB | FIFOST_TYPE_SPLIT_KEK);
92 
93 #ifdef DEBUG
94 	print_hex_dump(KERN_ERR, "ctx.key@"__stringify(__LINE__)": ",
95 		       DUMP_PREFIX_ADDRESS, 16, 4, key_in, keylen, 1);
96 	print_hex_dump(KERN_ERR, "jobdesc@"__stringify(__LINE__)": ",
97 		       DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
98 #endif
99 
100 	result.err = 0;
101 	init_completion(&result.completion);
102 
103 	ret = caam_jr_enqueue(jrdev, desc, split_key_done, &result);
104 	if (!ret) {
105 		/* in progress */
106 		wait_for_completion_interruptible(&result.completion);
107 		ret = result.err;
108 #ifdef DEBUG
109 		print_hex_dump(KERN_ERR, "ctx.key@"__stringify(__LINE__)": ",
110 			       DUMP_PREFIX_ADDRESS, 16, 4, key_out,
111 			       split_key_pad_len, 1);
112 #endif
113 	}
114 
115 	dma_unmap_single(jrdev, dma_addr_out, split_key_pad_len,
116 			 DMA_FROM_DEVICE);
117 out_unmap_in:
118 	dma_unmap_single(jrdev, dma_addr_in, keylen, DMA_TO_DEVICE);
119 out_free:
120 	kfree(desc);
121 	return ret;
122 }
123 EXPORT_SYMBOL(gen_split_key);
124