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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/*
18 * CAAM hardware constructs a job descriptor which points to a shared descriptor
19 * (as pointed by context_a of to-CAAM FQ).
20 * When the job descriptor is executed by DECO, the whole job descriptor
21 * together with shared descriptor gets loaded in DECO buffer, which is
22 * 64 words (each 32-bit) long.
23 *
24 * The job descriptor constructed by CAAM hardware has the following layout:
25 *
26 * HEADER (1 word)
27 * Shdesc ptr (1 or 2 words)
28 * SEQ_OUT_PTR (1 word)
29 * Out ptr (1 or 2 words)
30 * Out length (1 word)
31 * SEQ_IN_PTR (1 word)
32 * In ptr (1 or 2 words)
33 * In length (1 word)
34 *
35 * The shdesc ptr is used to fetch shared descriptor contents into DECO buffer.
36 *
37 * Apart from shdesc contents, the total number of words that get loaded in DECO
38 * buffer are '8' or '11'. The remaining words in DECO buffer can be used for
39 * storing shared descriptor.
40 */
41#define MAX_SDLEN ((CAAM_DESC_BYTES_MAX - DESC_JOB_IO_LEN) / CAAM_CMD_SZ)
42
43/* Length of a single buffer in the QI driver memory cache */
44#define CAAM_QI_MEMCACHE_SIZE 768
45
46extern bool caam_congested __read_mostly;
47
48/*
49 * This is the request structure the driver application should fill while
50 * submitting a job to driver.
51 */
52struct caam_drv_req;
53
54/*
55 * caam_qi_cbk - application's callback function invoked by the driver when the
56 * request has been successfully processed.
57 * @drv_req: original request that was submitted
58 * @status: completion status of request (0 - success, non-zero - error code)
59 */
60typedef void (*caam_qi_cbk)(struct caam_drv_req *drv_req, u32 status);
61
62enum optype {
63 ENCRYPT,
64 DECRYPT,
65 NUM_OP
66};
67
68/**
69 * caam_drv_ctx - CAAM/QI backend driver context
70 *
71 * The jobs are processed by the driver against a driver context.
72 * With every cryptographic context, a driver context is attached.
73 * The driver context contains data for private use by driver.
74 * For the applications, this is an opaque structure.
75 *
76 * @prehdr: preheader placed before shrd desc
77 * @sh_desc: shared descriptor
78 * @context_a: shared descriptor dma address
79 * @req_fq: to-CAAM request frame queue
80 * @rsp_fq: from-CAAM response frame queue
81 * @cpu: cpu on which to receive CAAM response
82 * @op_type: operation type
83 * @qidev: device pointer for CAAM/QI backend
84 */
85struct caam_drv_ctx {
86 u32 prehdr[2];
87 u32 sh_desc[MAX_SDLEN];
88 dma_addr_t context_a;
89 struct qman_fq *req_fq;
90 struct qman_fq *rsp_fq;
91 int cpu;
92 enum optype op_type;
93 struct device *qidev;
94} ____cacheline_aligned;
95
96/**
97 * caam_drv_req - The request structure the driver application should fill while
98 * submitting a job to driver.
99 * @fd_sgt: QMan S/G pointing to output (fd_sgt[0]) and input (fd_sgt[1])
100 * buffers.
101 * @cbk: callback function to invoke when job is completed
102 * @app_ctx: arbitrary context attached with request by the application
103 *
104 * The fields mentioned below should not be used by application.
105 * These are for private use by driver.
106 *
107 * @hdr__: linked list header to maintain list of outstanding requests to CAAM
108 * @hwaddr: DMA address for the S/G table.
109 */
110struct caam_drv_req {
111 struct qm_sg_entry fd_sgt[2];
112 struct caam_drv_ctx *drv_ctx;
113 caam_qi_cbk cbk;
114 void *app_ctx;
115} ____cacheline_aligned;
116
117/**
118 * caam_drv_ctx_init - Initialise a CAAM/QI driver context
119 *
120 * A CAAM/QI driver context must be attached with each cryptographic context.
121 * This function allocates memory for CAAM/QI context and returns a handle to
122 * the application. This handle must be submitted along with each enqueue
123 * request to the driver by the application.
124 *
125 * @cpu: CPU where the application prefers to the driver to receive CAAM
126 * responses. The request completion callback would be issued from this
127 * CPU.
128 * @sh_desc: shared descriptor pointer to be attached with CAAM/QI driver
129 * context.
130 *
131 * Returns a driver context on success or negative error code on failure.
132 */
133struct caam_drv_ctx *caam_drv_ctx_init(struct device *qidev, int *cpu,
134 u32 *sh_desc);
135
136/**
137 * caam_qi_enqueue - Submit a request to QI backend driver.
138 *
139 * The request structure must be properly filled as described above.
140 *
141 * @qidev: device pointer for QI backend
142 * @req: CAAM QI request structure
143 *
144 * Returns 0 on success or negative error code on failure.
145 */
146int caam_qi_enqueue(struct device *qidev, struct caam_drv_req *req);
147
148/**
149 * caam_drv_ctx_busy - Check if there are too many jobs pending with CAAM
150 * or too many CAAM responses are pending to be processed.
151 * @drv_ctx: driver context for which job is to be submitted
152 *
153 * Returns caam congestion status 'true/false'
154 */
155bool caam_drv_ctx_busy(struct caam_drv_ctx *drv_ctx);
156
157/**
158 * caam_drv_ctx_update - Update QI driver context
159 *
160 * Invoked when shared descriptor is required to be change in driver context.
161 *
162 * @drv_ctx: driver context to be updated
163 * @sh_desc: new shared descriptor pointer to be updated in QI driver context
164 *
165 * Returns 0 on success or negative error code on failure.
166 */
167int caam_drv_ctx_update(struct caam_drv_ctx *drv_ctx, u32 *sh_desc);
168
169/**
170 * caam_drv_ctx_rel - Release a QI driver context
171 * @drv_ctx: context to be released
172 */
173void caam_drv_ctx_rel(struct caam_drv_ctx *drv_ctx);
174
175int caam_qi_init(struct platform_device *pdev);
176void caam_qi_shutdown(struct device *dev);
177
178/**
179 * qi_cache_alloc - Allocate buffers from CAAM-QI cache
180 *
181 * Invoked when a user of the CAAM-QI (i.e. caamalg-qi) needs data which has
182 * to be allocated on the hotpath. Instead of using malloc, one can use the
183 * services of the CAAM QI memory cache (backed by kmem_cache). The buffers
184 * will have a size of 256B, which is sufficient for hosting 16 SG entries.
185 *
186 * @flags: flags that would be used for the equivalent malloc(..) call
187 *
188 * Returns a pointer to a retrieved buffer on success or NULL on failure.
189 */
190void *qi_cache_alloc(gfp_t flags);
191
192/**
193 * qi_cache_free - Frees buffers allocated from CAAM-QI cache
194 *
195 * Invoked when a user of the CAAM-QI (i.e. caamalg-qi) no longer needs
196 * the buffer previously allocated by a qi_cache_alloc call.
197 * No checking is being done, the call is a passthrough call to
198 * kmem_cache_free(...)
199 *
200 * @obj: object previously allocated using qi_cache_alloc()
201 */
202void qi_cache_free(void *obj);
203
204#endif /* __QI_H__ */