1 /* SPDX-License-Identifier: BSD-3-Clause */
2 /* Copyright(c) 2007-2022 Intel Corporation */
3 /* $FreeBSD$ */
4 
5 /**
6  ***************************************************************************
7  * @file lac_sym_partial.h
8  *
9  * @defgroup LacSymPartial  Partial Packets
10  *
11  * @ingroup LacSymCommon
12  *
13  * Partial packet handling code
14  *
15  * @lld_start
16  *
17  * <b>Partials In Flight</b>\n
18  * The API states that for partial packets the client should not submit
19  * the next partial request until the callback for the current partial has
20  * been called. We have chosen to enforce this rather than letting the user
21  * proceed where they would get an incorrect digest, cipher result.
22  *
23  * Maintain a SpinLock for partials in flight per session. Try and acquire this
24  * SpinLock. If it cant be acquired return an error straight away to the client
25  * as there is already a partial in flight. There is no blocking in the data
26  * path for this.
27  *
28  * By preventing any other partials from coming in while a partial is in flight
29  * we can check and change the state of the session without having to lock
30  * round it (dont want to have to lock and block in the data path). The state
31  * of the session indicates the previous packet type that a request was
32  * successfully completed for. The last packet type is only updated for partial
33  * packets. This state determines the packet types that can be accepted.
34  * e.g a last partial will not be accepted unless the previous packet was a
35  * partial. By only allowing one partial packet to be in flight, there is no
36  * need to lock around the update of the previous packet type for the session.
37  *
38  * The ECB Cipher mode, ciphers each block separately. No state is maintained
39  * between blocks. There is no need to wait for the callback for previous
40  * partial in ECB mode as the result of the previous partial has no impact on
41  * it. The API and our implementation only allows 1 partial packet to be in
42  * flight per session, therefore a partial packet request for ECB mode must
43  * be fully completed (ie. callback called) before the next partial request
44  * can be issued.
45  *
46  * <b>Partial Ordering</b>\n
47  * The ordering that the user submits partial packets will be checked.
48  * (we could have let the user proceed where they will get an incorrect
49  * digest/cipher result but chose against this).
50  *
51  *  -# Maintain the last packet type of a partial operation for the session. If
52  *     there have been no previous partials, we will accept only first partials
53  *  -# The state must be set to partial before we will accept a final partial.
54  *     i.e. a partial request must have already completed.
55  *
56  * The last packet type is updated in the callback for partial packets as this
57  * is the only place we can guarantee that a partial packet operation has been
58  * completed. When a partial completes the state can be updated from FULL to
59  * PARTIAL. The SpinLock for partial packets in flight for the session can be
60  * unlocked at this point. On a final Partial request the last packet type is
61  * reset back to FULL. NOTE: This is not done at the same time as the check in
62  * the perform as if an error occurs we would have to roll back the state
63  *
64  * For Hash mode it is possible to interleave full and a single partial
65  * packet stream in a session as the hash state buffer is updated for partial
66  * packets. It is not touched by full packets. For cipher mode, as the client
67  * manages the state, they can interleave full and a single partial packets.
68  * For ARC4, the state is managed internally and the packet type will always
69  * be set to partial internally.
70  *
71  * @lld_end
72  *
73  ***************************************************************************/
74 
75 /***************************************************************************/
76 
77 #ifndef LAC_SYM_PARTIAL_H
78 #define LAC_SYM_PARTIAL_H
79 
80 #include "cpa.h"
81 #include "cpa_cy_sym.h"
82 
83 /***************************************************************************/
84 
85 /**
86 *******************************************************************************
87 * @ingroup LacSymPartial
88 *      check if partial packet request is valid for a session
89 *
90 * @description
91 *      This function checks to see if there is a partial packet request in
92 *      flight and then if the partial state is correct
93 *
94 * @param[in]  packetType               Partial packet request
95 * @param[in]  partialState             Partial state of session
96 *
97 * @retval CPA_STATUS_SUCCESS           Normal Operation
98 * @retval CPA_STATUS_INVALID_PARAM     Invalid Parameter
99 *
100 *****************************************************************************/
101 CpaStatus LacSym_PartialPacketStateCheck(CpaCySymPacketType packetType,
102 					 CpaCySymPacketType partialState);
103 
104 /**
105 *******************************************************************************
106 * @ingroup LacSymPartial
107 *      update the state of the partial packet in a session
108 *
109 * @description
110 *      This function is called in callback operation. It updates the state
111 *      of a partial packet in a session and indicates that there is no
112 *      longer a partial packet in flight for the session
113 *
114 * @param[in]  packetType           Partial packet request
115 * @param[out] pPartialState        Pointer to partial state of session
116 *
117 *****************************************************************************/
118 void LacSym_PartialPacketStateUpdate(CpaCySymPacketType packetType,
119 				     CpaCySymPacketType *pPartialState);
120 
121 #endif /* LAC_SYM_PARTIAL_H */
122