xref: /openbmc/linux/drivers/crypto/caam/qi.h (revision a44e4f3a)
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 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  * @cpu: cpu on which to receive CAAM response
56  * @op_type: operation type
57  * @qidev: device pointer for CAAM/QI backend
58  */
59 struct caam_drv_ctx {
60 	u32 prehdr[2];
61 	u32 sh_desc[MAX_SDLEN];
62 	dma_addr_t context_a;
63 	struct qman_fq *req_fq;
64 	struct qman_fq *rsp_fq;
65 	int cpu;
66 	enum optype op_type;
67 	struct device *qidev;
68 } ____cacheline_aligned;
69 
70 /**
71  * caam_drv_req - The request structure the driver application should fill while
72  *                submitting a job to driver.
73  * @fd_sgt: QMan S/G pointing to output (fd_sgt[0]) and input (fd_sgt[1])
74  *          buffers.
75  * @cbk: callback function to invoke when job is completed
76  * @app_ctx: arbitrary context attached with request by the application
77  *
78  * The fields mentioned below should not be used by application.
79  * These are for private use by driver.
80  *
81  * @hdr__: linked list header to maintain list of outstanding requests to CAAM
82  * @hwaddr: DMA address for the S/G table.
83  */
84 struct caam_drv_req {
85 	struct qm_sg_entry fd_sgt[2];
86 	struct caam_drv_ctx *drv_ctx;
87 	caam_qi_cbk cbk;
88 	void *app_ctx;
89 } ____cacheline_aligned;
90 
91 /**
92  * caam_drv_ctx_init - Initialise a CAAM/QI driver context
93  *
94  * A CAAM/QI driver context must be attached with each cryptographic context.
95  * This function allocates memory for CAAM/QI context and returns a handle to
96  * the application. This handle must be submitted along with each enqueue
97  * request to the driver by the application.
98  *
99  * @cpu: CPU where the application prefers to the driver to receive CAAM
100  *       responses. The request completion callback would be issued from this
101  *       CPU.
102  * @sh_desc: shared descriptor pointer to be attached with CAAM/QI driver
103  *           context.
104  *
105  * Returns a driver context on success or negative error code on failure.
106  */
107 struct caam_drv_ctx *caam_drv_ctx_init(struct device *qidev, int *cpu,
108 				       u32 *sh_desc);
109 
110 /**
111  * caam_qi_enqueue - Submit a request to QI backend driver.
112  *
113  * The request structure must be properly filled as described above.
114  *
115  * @qidev: device pointer for QI backend
116  * @req: CAAM QI request structure
117  *
118  * Returns 0 on success or negative error code on failure.
119  */
120 int caam_qi_enqueue(struct device *qidev, struct caam_drv_req *req);
121 
122 /**
123  * caam_drv_ctx_busy - Check if there are too many jobs pending with CAAM
124  *		       or too many CAAM responses are pending to be processed.
125  * @drv_ctx: driver context for which job is to be submitted
126  *
127  * Returns caam congestion status 'true/false'
128  */
129 bool caam_drv_ctx_busy(struct caam_drv_ctx *drv_ctx);
130 
131 /**
132  * caam_drv_ctx_update - Update QI driver context
133  *
134  * Invoked when shared descriptor is required to be change in driver context.
135  *
136  * @drv_ctx: driver context to be updated
137  * @sh_desc: new shared descriptor pointer to be updated in QI driver context
138  *
139  * Returns 0 on success or negative error code on failure.
140  */
141 int caam_drv_ctx_update(struct caam_drv_ctx *drv_ctx, u32 *sh_desc);
142 
143 /**
144  * caam_drv_ctx_rel - Release a QI driver context
145  * @drv_ctx: context to be released
146  */
147 void caam_drv_ctx_rel(struct caam_drv_ctx *drv_ctx);
148 
149 int caam_qi_init(struct platform_device *pdev);
150 void caam_qi_shutdown(struct device *dev);
151 
152 /**
153  * qi_cache_alloc - Allocate buffers from CAAM-QI cache
154  *
155  * Invoked when a user of the CAAM-QI (i.e. caamalg-qi) needs data which has
156  * to be allocated on the hotpath. Instead of using malloc, one can use the
157  * services of the CAAM QI memory cache (backed by kmem_cache). The buffers
158  * will have a size of 256B, which is sufficient for hosting 16 SG entries.
159  *
160  * @flags: flags that would be used for the equivalent malloc(..) call
161  *
162  * Returns a pointer to a retrieved buffer on success or NULL on failure.
163  */
164 void *qi_cache_alloc(gfp_t flags);
165 
166 /**
167  * qi_cache_free - Frees buffers allocated from CAAM-QI cache
168  *
169  * Invoked when a user of the CAAM-QI (i.e. caamalg-qi) no longer needs
170  * the buffer previously allocated by a qi_cache_alloc call.
171  * No checking is being done, the call is a passthrough call to
172  * kmem_cache_free(...)
173  *
174  * @obj: object previously allocated using qi_cache_alloc()
175  */
176 void qi_cache_free(void *obj);
177 
178 #endif /* __QI_H__ */
179