xref: /openbmc/linux/drivers/crypto/caam/qi.h (revision 37744fee)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Public definitions for the CAAM/QI (Queue Interface) backend.
4  *
5  * Copyright 2013-2016 Freescale Semiconductor, Inc.
6  * Copyright 2016-2017, 2020 NXP
7  */
8 
9 #ifndef __QI_H__
10 #define __QI_H__
11 
12 #include <soc/fsl/qman.h>
13 #include "compat.h"
14 #include "desc.h"
15 #include "desc_constr.h"
16 
17 /* Length of a single buffer in the QI driver memory cache */
18 #define CAAM_QI_MEMCACHE_SIZE	768
19 
20 extern bool caam_congested __read_mostly;
21 
22 /*
23  * This is the request structure the driver application should fill while
24  * submitting a job to driver.
25  */
26 struct caam_drv_req;
27 
28 /*
29  * caam_qi_cbk - application's callback function invoked by the driver when the
30  *               request has been successfully processed.
31  * @drv_req: original request that was submitted
32  * @status: completion status of request (0 - success, non-zero - error code)
33  */
34 typedef void (*caam_qi_cbk)(struct caam_drv_req *drv_req, u32 status);
35 
36 enum optype {
37 	ENCRYPT,
38 	DECRYPT,
39 	NUM_OP
40 };
41 
42 /**
43  * caam_drv_ctx - CAAM/QI backend driver context
44  *
45  * The jobs are processed by the driver against a driver context.
46  * With every cryptographic context, a driver context is attached.
47  * The driver context contains data for private use by driver.
48  * For the applications, this is an opaque structure.
49  *
50  * @prehdr: preheader placed before shrd desc
51  * @sh_desc: shared descriptor
52  * @context_a: shared descriptor dma address
53  * @req_fq: to-CAAM request frame queue
54  * @rsp_fq: from-CAAM response frame queue
55  * @refcnt: reference counter incremented for each frame enqueued in to-CAAM FQ
56  * @cpu: cpu on which to receive CAAM response
57  * @op_type: operation type
58  * @qidev: device pointer for CAAM/QI backend
59  */
60 struct caam_drv_ctx {
61 	u32 prehdr[2];
62 	u32 sh_desc[MAX_SDLEN];
63 	dma_addr_t context_a;
64 	struct qman_fq *req_fq;
65 	struct qman_fq *rsp_fq;
66 	refcount_t refcnt;
67 	int cpu;
68 	enum optype op_type;
69 	struct device *qidev;
70 } ____cacheline_aligned;
71 
72 /**
73  * caam_drv_req - The request structure the driver application should fill while
74  *                submitting a job to driver.
75  * @fd_sgt: QMan S/G pointing to output (fd_sgt[0]) and input (fd_sgt[1])
76  *          buffers.
77  * @cbk: callback function to invoke when job is completed
78  * @app_ctx: arbitrary context attached with request by the application
79  *
80  * The fields mentioned below should not be used by application.
81  * These are for private use by driver.
82  *
83  * @hdr__: linked list header to maintain list of outstanding requests to CAAM
84  * @hwaddr: DMA address for the S/G table.
85  */
86 struct caam_drv_req {
87 	struct qm_sg_entry fd_sgt[2];
88 	struct caam_drv_ctx *drv_ctx;
89 	caam_qi_cbk cbk;
90 	void *app_ctx;
91 } ____cacheline_aligned;
92 
93 /**
94  * caam_drv_ctx_init - Initialise a CAAM/QI driver context
95  *
96  * A CAAM/QI driver context must be attached with each cryptographic context.
97  * This function allocates memory for CAAM/QI context and returns a handle to
98  * the application. This handle must be submitted along with each enqueue
99  * request to the driver by the application.
100  *
101  * @cpu: CPU where the application prefers to the driver to receive CAAM
102  *       responses. The request completion callback would be issued from this
103  *       CPU.
104  * @sh_desc: shared descriptor pointer to be attached with CAAM/QI driver
105  *           context.
106  *
107  * Returns a driver context on success or negative error code on failure.
108  */
109 struct caam_drv_ctx *caam_drv_ctx_init(struct device *qidev, int *cpu,
110 				       u32 *sh_desc);
111 
112 /**
113  * caam_qi_enqueue - Submit a request to QI backend driver.
114  *
115  * The request structure must be properly filled as described above.
116  *
117  * @qidev: device pointer for QI backend
118  * @req: CAAM QI request structure
119  *
120  * Returns 0 on success or negative error code on failure.
121  */
122 int caam_qi_enqueue(struct device *qidev, struct caam_drv_req *req);
123 
124 /**
125  * caam_drv_ctx_busy - Check if there are too many jobs pending with CAAM
126  *		       or too many CAAM responses are pending to be processed.
127  * @drv_ctx: driver context for which job is to be submitted
128  *
129  * Returns caam congestion status 'true/false'
130  */
131 bool caam_drv_ctx_busy(struct caam_drv_ctx *drv_ctx);
132 
133 /**
134  * caam_drv_ctx_update - Update QI driver context
135  *
136  * Invoked when shared descriptor is required to be change in driver context.
137  *
138  * @drv_ctx: driver context to be updated
139  * @sh_desc: new shared descriptor pointer to be updated in QI driver context
140  *
141  * Returns 0 on success or negative error code on failure.
142  */
143 int caam_drv_ctx_update(struct caam_drv_ctx *drv_ctx, u32 *sh_desc);
144 
145 /**
146  * caam_drv_ctx_rel - Release a QI driver context
147  * @drv_ctx: context to be released
148  */
149 void caam_drv_ctx_rel(struct caam_drv_ctx *drv_ctx);
150 
151 int caam_qi_init(struct platform_device *pdev);
152 
153 /**
154  * qi_cache_alloc - Allocate buffers from CAAM-QI cache
155  *
156  * Invoked when a user of the CAAM-QI (i.e. caamalg-qi) needs data which has
157  * to be allocated on the hotpath. Instead of using malloc, one can use the
158  * services of the CAAM QI memory cache (backed by kmem_cache). The buffers
159  * will have a size of 256B, which is sufficient for hosting 16 SG entries.
160  *
161  * @flags: flags that would be used for the equivalent malloc(..) call
162  *
163  * Returns a pointer to a retrieved buffer on success or NULL on failure.
164  */
165 void *qi_cache_alloc(gfp_t flags);
166 
167 /**
168  * qi_cache_free - Frees buffers allocated from CAAM-QI cache
169  *
170  * Invoked when a user of the CAAM-QI (i.e. caamalg-qi) no longer needs
171  * the buffer previously allocated by a qi_cache_alloc call.
172  * No checking is being done, the call is a passthrough call to
173  * kmem_cache_free(...)
174  *
175  * @obj: object previously allocated using qi_cache_alloc()
176  */
177 void qi_cache_free(void *obj);
178 
179 #endif /* __QI_H__ */
180