summaryrefslogtreecommitdiffstats
path: root/drivers/crypto/caam/qi.h
blob: ecb21f207637bda96aebd0a410a6de58be5bcc5c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
/*
 * Public definitions for the CAAM/QI (Queue Interface) backend.
 *
 * Copyright 2013-2016 Freescale Semiconductor, Inc.
 * Copyright 2016-2017 NXP
 */

#ifndef __QI_H__
#define __QI_H__

#include <soc/fsl/qman.h>
#include "compat.h"
#include "desc.h"
#include "desc_constr.h"

/*
 * CAAM hardware constructs a job descriptor which points to a shared descriptor
 * (as pointed by context_a of to-CAAM FQ).
 * When the job descriptor is executed by DECO, the whole job descriptor
 * together with shared descriptor gets loaded in DECO buffer, which is
 * 64 words (each 32-bit) long.
 *
 * The job descriptor constructed by CAAM hardware has the following layout:
 *
 *	HEADER		(1 word)
 *	Shdesc ptr	(1 or 2 words)
 *	SEQ_OUT_PTR	(1 word)
 *	Out ptr		(1 or 2 words)
 *	Out length	(1 word)
 *	SEQ_IN_PTR	(1 word)
 *	In ptr		(1 or 2 words)
 *	In length	(1 word)
 *
 * The shdesc ptr is used to fetch shared descriptor contents into DECO buffer.
 *
 * Apart from shdesc contents, the total number of words that get loaded in DECO
 * buffer are '8' or '11'. The remaining words in DECO buffer can be used for
 * storing shared descriptor.
 */
#define MAX_SDLEN	((CAAM_DESC_BYTES_MAX - DESC_JOB_IO_LEN) / CAAM_CMD_SZ)

/* Length of a single buffer in the QI driver memory cache */
#define CAAM_QI_MEMCACHE_SIZE	768

extern bool caam_congested __read_mostly;

/*
 * This is the request structure the driver application should fill while
 * submitting a job to driver.
 */
struct caam_drv_req;

/*
 * caam_qi_cbk - application's callback function invoked by the driver when the
 *               request has been successfully processed.
 * @drv_req: original request that was submitted
 * @status: completion status of request (0 - success, non-zero - error code)
 */
typedef void (*caam_qi_cbk)(struct caam_drv_req *drv_req, u32 status);

enum optype {
	ENCRYPT,
	DECRYPT,
	GIVENCRYPT,
	NUM_OP
};

/**
 * caam_drv_ctx - CAAM/QI backend driver context
 *
 * The jobs are processed by the driver against a driver context.
 * With every cryptographic context, a driver context is attached.
 * The driver context contains data for private use by driver.
 * For the applications, this is an opaque structure.
 *
 * @prehdr: preheader placed before shrd desc
 * @sh_desc: shared descriptor
 * @context_a: shared descriptor dma address
 * @req_fq: to-CAAM request frame queue
 * @rsp_fq: from-CAAM response frame queue
 * @cpu: cpu on which to receive CAAM response
 * @op_type: operation type
 * @qidev: device pointer for CAAM/QI backend
 */
struct caam_drv_ctx {
	u32 prehdr[2];
	u32 sh_desc[MAX_SDLEN];
	dma_addr_t context_a;
	struct qman_fq *req_fq;
	struct qman_fq *rsp_fq;
	int cpu;
	enum optype op_type;
	struct device *qidev;
} ____cacheline_aligned;

/**
 * caam_drv_req - The request structure the driver application should fill while
 *                submitting a job to driver.
 * @fd_sgt: QMan S/G pointing to output (fd_sgt[0]) and input (fd_sgt[1])
 *          buffers.
 * @cbk: callback function to invoke when job is completed
 * @app_ctx: arbitrary context attached with request by the application
 *
 * The fields mentioned below should not be used by application.
 * These are for private use by driver.
 *
 * @hdr__: linked list header to maintain list of outstanding requests to CAAM
 * @hwaddr: DMA address for the S/G table.
 */
struct caam_drv_req {
	struct qm_sg_entry fd_sgt[2];
	struct caam_drv_ctx *drv_ctx;
	caam_qi_cbk cbk;
	void *app_ctx;
} ____cacheline_aligned;

/**
 * caam_drv_ctx_init - Initialise a CAAM/QI driver context
 *
 * A CAAM/QI driver context must be attached with each cryptographic context.
 * This function allocates memory for CAAM/QI context and returns a handle to
 * the application. This handle must be submitted along with each enqueue
 * request to the driver by the application.
 *
 * @cpu: CPU where the application prefers to the driver to receive CAAM
 *       responses. The request completion callback would be issued from this
 *       CPU.
 * @sh_desc: shared descriptor pointer to be attached with CAAM/QI driver
 *           context.
 *
 * Returns a driver context on success or negative error code on failure.
 */
struct caam_drv_ctx *caam_drv_ctx_init(struct device *qidev, int *cpu,
				       u32 *sh_desc);

/**
 * caam_qi_enqueue - Submit a request to QI backend driver.
 *
 * The request structure must be properly filled as described above.
 *
 * @qidev: device pointer for QI backend
 * @req: CAAM QI request structure
 *
 * Returns 0 on success or negative error code on failure.
 */
int caam_qi_enqueue(struct device *qidev, struct caam_drv_req *req);

/**
 * caam_drv_ctx_busy - Check if there are too many jobs pending with CAAM
 *		       or too many CAAM responses are pending to be processed.
 * @drv_ctx: driver context for which job is to be submitted
 *
 * Returns caam congestion status 'true/false'
 */
bool caam_drv_ctx_busy(struct caam_drv_ctx *drv_ctx);

/**
 * caam_drv_ctx_update - Update QI driver context
 *
 * Invoked when shared descriptor is required to be change in driver context.
 *
 * @drv_ctx: driver context to be updated
 * @sh_desc: new shared descriptor pointer to be updated in QI driver context
 *
 * Returns 0 on success or negative error code on failure.
 */
int caam_drv_ctx_update(struct caam_drv_ctx *drv_ctx, u32 *sh_desc);

/**
 * caam_drv_ctx_rel - Release a QI driver context
 * @drv_ctx: context to be released
 */
void caam_drv_ctx_rel(struct caam_drv_ctx *drv_ctx);

int caam_qi_init(struct platform_device *pdev);
int caam_qi_shutdown(struct device *dev);

/**
 * qi_cache_alloc - Allocate buffers from CAAM-QI cache
 *
 * Invoked when a user of the CAAM-QI (i.e. caamalg-qi) needs data which has
 * to be allocated on the hotpath. Instead of using malloc, one can use the
 * services of the CAAM QI memory cache (backed by kmem_cache). The buffers
 * will have a size of 256B, which is sufficient for hosting 16 SG entries.
 *
 * @flags: flags that would be used for the equivalent malloc(..) call
 *
 * Returns a pointer to a retrieved buffer on success or NULL on failure.
 */
void *qi_cache_alloc(gfp_t flags);

/**
 * qi_cache_free - Frees buffers allocated from CAAM-QI cache
 *
 * Invoked when a user of the CAAM-QI (i.e. caamalg-qi) no longer needs
 * the buffer previously allocated by a qi_cache_alloc call.
 * No checking is being done, the call is a passthrough call to
 * kmem_cache_free(...)
 *
 * @obj: object previously allocated using qi_cache_alloc()
 */
void qi_cache_free(void *obj);

#endif /* __QI_H__ */
OpenPOWER on IntegriCloud