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
|
/** @file
Stateful and implicitly initialized fw_cfg library implementation.
Copyright (C) 2013 - 2014, Red Hat, Inc.
Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>
(C) Copyright 2021 Hewlett Packard Enterprise Development LP<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Uefi.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/QemuFwCfgLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Protocol/FdtClient.h>
#include "QemuFwCfgLibMmioInternal.h"
UINTN mFwCfgSelectorAddress;
UINTN mFwCfgDataAddress;
UINTN mFwCfgDmaAddress;
RETURN_STATUS
EFIAPI
QemuFwCfgInitialize (
VOID
)
{
EFI_STATUS Status;
FDT_CLIENT_PROTOCOL *FdtClient;
CONST UINT64 *Reg;
UINT32 RegSize;
UINTN AddressCells, SizeCells;
UINT64 FwCfgSelectorAddress;
UINT64 FwCfgSelectorSize;
UINT64 FwCfgDataAddress;
UINT64 FwCfgDataSize;
UINT64 FwCfgDmaAddress;
UINT64 FwCfgDmaSize;
Status = gBS->LocateProtocol (
&gFdtClientProtocolGuid,
NULL,
(VOID **)&FdtClient
);
ASSERT_EFI_ERROR (Status);
Status = FdtClient->FindCompatibleNodeReg (
FdtClient,
"qemu,fw-cfg-mmio",
(CONST VOID **)&Reg,
&AddressCells,
&SizeCells,
&RegSize
);
if (EFI_ERROR (Status)) {
DEBUG ((
DEBUG_WARN,
"%a: No 'qemu,fw-cfg-mmio' compatible DT node found (Status == %r)\n",
__func__,
Status
));
return EFI_SUCCESS;
}
ASSERT (AddressCells == 2);
ASSERT (SizeCells == 2);
ASSERT (RegSize == 2 * sizeof (UINT64));
FwCfgDataAddress = SwapBytes64 (Reg[0]);
FwCfgDataSize = 8;
FwCfgSelectorAddress = FwCfgDataAddress + FwCfgDataSize;
FwCfgSelectorSize = 2;
//
// The following ASSERT()s express
//
// Address + Size - 1 <= MAX_UINTN
//
// for both registers, that is, that the last byte in each MMIO range is
// expressible as a MAX_UINTN. The form below is mathematically
// equivalent, and it also prevents any unsigned overflow before the
// comparison.
//
ASSERT (FwCfgSelectorAddress <= MAX_UINTN - FwCfgSelectorSize + 1);
ASSERT (FwCfgDataAddress <= MAX_UINTN - FwCfgDataSize + 1);
mFwCfgSelectorAddress = FwCfgSelectorAddress;
mFwCfgDataAddress = FwCfgDataAddress;
DEBUG ((
DEBUG_INFO,
"Found FwCfg @ 0x%Lx/0x%Lx\n",
FwCfgSelectorAddress,
FwCfgDataAddress
));
if (SwapBytes64 (Reg[1]) >= 0x18) {
FwCfgDmaAddress = FwCfgDataAddress + 0x10;
FwCfgDmaSize = 0x08;
//
// See explanation above.
//
ASSERT (FwCfgDmaAddress <= MAX_UINTN - FwCfgDmaSize + 1);
DEBUG ((DEBUG_INFO, "Found FwCfg DMA @ 0x%Lx\n", FwCfgDmaAddress));
} else {
FwCfgDmaAddress = 0;
}
if (QemuFwCfgIsAvailable ()) {
UINT32 Signature;
QemuFwCfgSelectItem (QemuFwCfgItemSignature);
Signature = QemuFwCfgRead32 ();
if (Signature == SIGNATURE_32 ('Q', 'E', 'M', 'U')) {
//
// For DMA support, we require the DTB to advertise the register, and the
// feature bitmap (which we read without DMA) to confirm the feature.
//
if (FwCfgDmaAddress != 0) {
UINT32 Features;
QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);
Features = QemuFwCfgRead32 ();
if ((Features & FW_CFG_F_DMA) != 0) {
mFwCfgDmaAddress = FwCfgDmaAddress;
InternalQemuFwCfgReadBytes = DmaReadBytes;
InternalQemuFwCfgWriteBytes = DmaWriteBytes;
InternalQemuFwCfgSkipBytes = DmaSkipBytes;
}
}
} else {
mFwCfgSelectorAddress = 0;
mFwCfgDataAddress = 0;
}
}
return RETURN_SUCCESS;
}
|
