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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
/** @file
Root SMI handler for VCPU hotplug SMIs.
Copyright (c) 2020, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <IndustryStandard/Q35MchIch9.h> // ICH9_APM_CNT
#include <Library/BaseLib.h> // CpuDeadLoop()
#include <Library/DebugLib.h> // ASSERT()
#include <Library/MmServicesTableLib.h> // gMmst
#include <Library/PcdLib.h> // PcdGetBool()
#include <Protocol/MmCpuIo.h> // EFI_MM_CPU_IO_PROTOCOL
#include <Uefi/UefiBaseType.h> // EFI_STATUS
//
// We use this protocol for accessing IO Ports.
//
STATIC EFI_MM_CPU_IO_PROTOCOL *mMmCpuIo;
//
// Represents the registration of the CPU Hotplug MMI handler.
//
STATIC EFI_HANDLE mDispatchHandle;
/**
CPU Hotplug MMI handler function.
This is a root MMI handler.
@param[in] DispatchHandle The unique handle assigned to this handler by
EFI_MM_SYSTEM_TABLE.MmiHandlerRegister().
@param[in] Context Context passed in by
EFI_MM_SYSTEM_TABLE.MmiManage(). Due to
CpuHotplugMmi() being a root MMI handler,
Context is ASSERT()ed to be NULL.
@param[in,out] CommBuffer Ignored, due to CpuHotplugMmi() being a root
MMI handler.
@param[in,out] CommBufferSize Ignored, due to CpuHotplugMmi() being a root
MMI handler.
@retval EFI_SUCCESS The MMI was handled and the MMI
source was quiesced. When returned
by a non-root MMI handler,
EFI_SUCCESS terminates the
processing of MMI handlers in
EFI_MM_SYSTEM_TABLE.MmiManage().
For a root MMI handler (i.e., for
the present function too),
EFI_SUCCESS behaves identically to
EFI_WARN_INTERRUPT_SOURCE_QUIESCED,
as further root MMI handlers are
going to be called by
EFI_MM_SYSTEM_TABLE.MmiManage()
anyway.
@retval EFI_WARN_INTERRUPT_SOURCE_QUIESCED The MMI source has been quiesced,
but other handlers should still
be called.
@retval EFI_WARN_INTERRUPT_SOURCE_PENDING The MMI source is still pending,
and other handlers should still
be called.
@retval EFI_INTERRUPT_PENDING The MMI source could not be
quiesced.
**/
STATIC
EFI_STATUS
EFIAPI
CpuHotplugMmi (
IN EFI_HANDLE DispatchHandle,
IN CONST VOID *Context OPTIONAL,
IN OUT VOID *CommBuffer OPTIONAL,
IN OUT UINTN *CommBufferSize OPTIONAL
)
{
EFI_STATUS Status;
UINT8 ApmControl;
//
// Assert that we are entering this function due to our root MMI handler
// registration.
//
ASSERT (DispatchHandle == mDispatchHandle);
//
// When MmiManage() is invoked to process root MMI handlers, the caller (the
// MM Core) is expected to pass in a NULL Context. MmiManage() then passes
// the same NULL Context to individual handlers.
//
ASSERT (Context == NULL);
//
// Read the MMI command value from the APM Control Port, to see if this is an
// MMI we should care about.
//
Status = mMmCpuIo->Io.Read (mMmCpuIo, MM_IO_UINT8, ICH9_APM_CNT, 1,
&ApmControl);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "%a: failed to read ICH9_APM_CNT: %r\n", __FUNCTION__,
Status));
//
// We couldn't even determine if the MMI was for us or not.
//
goto Fatal;
}
if (ApmControl != ICH9_APM_CNT_CPU_HOTPLUG) {
//
// The MMI is not for us.
//
return EFI_WARN_INTERRUPT_SOURCE_QUIESCED;
}
//
// We've handled this MMI.
//
return EFI_SUCCESS;
Fatal:
ASSERT (FALSE);
CpuDeadLoop ();
//
// We couldn't handle this MMI.
//
return EFI_INTERRUPT_PENDING;
}
//
// Entry point function of this driver.
//
EFI_STATUS
EFIAPI
CpuHotplugEntry (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
//
// This module should only be included when SMM support is required.
//
ASSERT (FeaturePcdGet (PcdSmmSmramRequire));
//
// This driver depends on the dynamically detected "SMRAM at default SMBASE"
// feature.
//
if (!PcdGetBool (PcdQ35SmramAtDefaultSmbase)) {
return EFI_UNSUPPORTED;
}
//
// Errors from here on are fatal; we cannot allow the boot to proceed if we
// can't set up this driver to handle CPU hotplug.
//
// First, collect the protocols needed later. All of these protocols are
// listed in our module DEPEX.
//
Status = gMmst->MmLocateProtocol (&gEfiMmCpuIoProtocolGuid,
NULL /* Registration */, (VOID **)&mMmCpuIo);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "%a: locate MmCpuIo: %r\n", __FUNCTION__, Status));
goto Fatal;
}
//
// Register the handler for the CPU Hotplug MMI.
//
Status = gMmst->MmiHandlerRegister (
CpuHotplugMmi,
NULL, // HandlerType: root MMI handler
&mDispatchHandle
);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "%a: MmiHandlerRegister(): %r\n", __FUNCTION__,
Status));
goto Fatal;
}
return EFI_SUCCESS;
Fatal:
ASSERT (FALSE);
CpuDeadLoop ();
return Status;
}
|
