1 /** @file
2
3 Copyright (c) 2016 HP Development Company, L.P.
4 Copyright (c) 2016 - 2021, Arm Limited. All rights reserved.
5
6 SPDX-License-Identifier: BSD-2-Clause-Patent
7
8 **/
9
10 #include <Base.h>
11 #include <Pi/PiMmCis.h>
12
13
14 #include <Library/ArmSvcLib.h>
15 #include <Library/ArmLib.h>
16 #include <Library/BaseMemoryLib.h>
17 #include <Library/DebugLib.h>
18 #include <Library/HobLib.h>
19
20 #include <Protocol/DebugSupport.h> // for EFI_SYSTEM_CONTEXT
21
22 #include <Guid/ZeroGuid.h>
23 #include <Guid/MmramMemoryReserve.h>
24
25 #include <IndustryStandard/ArmFfaSvc.h>
26 #include <IndustryStandard/ArmStdSmc.h>
27
28 #include "StandaloneMmCpu.h"
29
30 EFI_STATUS
31 EFIAPI
32 MmFoundationEntryRegister (
33 IN CONST EFI_MM_CONFIGURATION_PROTOCOL *This,
34 IN EFI_MM_ENTRY_POINT MmEntryPoint
35 );
36
37 //
38 // On ARM platforms every event is expected to have a GUID associated with
39 // it. It will be used by the MM Entry point to find the handler for the
40 // event. It will either be populated in a EFI_MM_COMMUNICATE_HEADER by the
41 // caller of the event (e.g. MM_COMMUNICATE SMC) or by the CPU driver
42 // (e.g. during an asynchronous event). In either case, this context is
43 // maintained in an array which has an entry for each CPU. The pointer to this
44 // array is held in PerCpuGuidedEventContext. Memory is allocated once the
45 // number of CPUs in the system are made known through the
46 // MP_INFORMATION_HOB_DATA.
47 //
48 EFI_MM_COMMUNICATE_HEADER **PerCpuGuidedEventContext = NULL;
49
50 // Descriptor with whereabouts of memory used for communication with the normal world
51 EFI_MMRAM_DESCRIPTOR mNsCommBuffer;
52
53 MP_INFORMATION_HOB_DATA *mMpInformationHobData;
54
55 EFI_MM_CONFIGURATION_PROTOCOL mMmConfig = {
56 0,
57 MmFoundationEntryRegister
58 };
59
60 STATIC EFI_MM_ENTRY_POINT mMmEntryPoint = NULL;
61
62 /**
63 The PI Standalone MM entry point for the TF-A CPU driver.
64
65 @param [in] EventId The event Id.
66 @param [in] CpuNumber The CPU number.
67 @param [in] NsCommBufferAddr Address of the NS common buffer.
68
69 @retval EFI_SUCCESS Success.
70 @retval EFI_INVALID_PARAMETER A parameter was invalid.
71 @retval EFI_ACCESS_DENIED Access not permitted.
72 @retval EFI_OUT_OF_RESOURCES Out of resources.
73 @retval EFI_UNSUPPORTED Operation not supported.
74 **/
75 EFI_STATUS
PiMmStandaloneArmTfCpuDriverEntry(IN UINTN EventId,IN UINTN CpuNumber,IN UINTN NsCommBufferAddr)76 PiMmStandaloneArmTfCpuDriverEntry (
77 IN UINTN EventId,
78 IN UINTN CpuNumber,
79 IN UINTN NsCommBufferAddr
80 )
81 {
82 EFI_MM_COMMUNICATE_HEADER *GuidedEventContext;
83 EFI_MM_ENTRY_CONTEXT MmEntryPointContext;
84 EFI_STATUS Status;
85 UINTN NsCommBufferSize;
86
87 DEBUG ((DEBUG_INFO, "Received event - 0x%x on cpu %d\n", EventId, CpuNumber));
88
89 Status = EFI_SUCCESS;
90 //
91 // ARM TF passes SMC FID of the MM_COMMUNICATE interface as the Event ID upon
92 // receipt of a synchronous MM request. Use the Event ID to distinguish
93 // between synchronous and asynchronous events.
94 //
95 if ((ARM_SMC_ID_MM_COMMUNICATE_AARCH64 != EventId) &&
96 (ARM_SVC_ID_FFA_MSG_SEND_DIRECT_REQ_AARCH64 != EventId)) {
97 DEBUG ((DEBUG_INFO, "UnRecognized Event - 0x%x\n", EventId));
98 return EFI_INVALID_PARAMETER;
99 }
100
101 // Perform parameter validation of NsCommBufferAddr
102 if (NsCommBufferAddr == (UINTN)NULL) {
103 return EFI_INVALID_PARAMETER;
104 }
105
106 if (NsCommBufferAddr < mNsCommBuffer.PhysicalStart) {
107 return EFI_ACCESS_DENIED;
108 }
109
110 if ((NsCommBufferAddr + sizeof (EFI_MM_COMMUNICATE_HEADER)) >=
111 (mNsCommBuffer.PhysicalStart + mNsCommBuffer.PhysicalSize)) {
112 return EFI_INVALID_PARAMETER;
113 }
114
115 // Find out the size of the buffer passed
116 NsCommBufferSize = ((EFI_MM_COMMUNICATE_HEADER *) NsCommBufferAddr)->MessageLength +
117 sizeof (EFI_MM_COMMUNICATE_HEADER);
118
119 // perform bounds check.
120 if (NsCommBufferAddr + NsCommBufferSize >=
121 mNsCommBuffer.PhysicalStart + mNsCommBuffer.PhysicalSize) {
122 return EFI_ACCESS_DENIED;
123 }
124
125 GuidedEventContext = NULL;
126 // Now that the secure world can see the normal world buffer, allocate
127 // memory to copy the communication buffer to the secure world.
128 Status = mMmst->MmAllocatePool (
129 EfiRuntimeServicesData,
130 NsCommBufferSize,
131 (VOID **) &GuidedEventContext
132 );
133
134 if (Status != EFI_SUCCESS) {
135 DEBUG ((DEBUG_INFO, "Mem alloc failed - 0x%x\n", EventId));
136 return EFI_OUT_OF_RESOURCES;
137 }
138
139 // X1 contains the VA of the normal world memory accessible from
140 // S-EL0
141 CopyMem (GuidedEventContext, (CONST VOID *) NsCommBufferAddr, NsCommBufferSize);
142
143 // Stash the pointer to the allocated Event Context for this CPU
144 PerCpuGuidedEventContext[CpuNumber] = GuidedEventContext;
145
146 ZeroMem (&MmEntryPointContext, sizeof (EFI_MM_ENTRY_CONTEXT));
147
148 MmEntryPointContext.CurrentlyExecutingCpu = CpuNumber;
149 MmEntryPointContext.NumberOfCpus = mMpInformationHobData->NumberOfProcessors;
150
151 // Populate the MM system table with MP and state information
152 mMmst->CurrentlyExecutingCpu = CpuNumber;
153 mMmst->NumberOfCpus = mMpInformationHobData->NumberOfProcessors;
154 mMmst->CpuSaveStateSize = 0;
155 mMmst->CpuSaveState = NULL;
156
157 if (mMmEntryPoint == NULL) {
158 DEBUG ((DEBUG_INFO, "Mm Entry point Not Found\n"));
159 return EFI_UNSUPPORTED;
160 }
161
162 mMmEntryPoint (&MmEntryPointContext);
163
164 // Free the memory allocation done earlier and reset the per-cpu context
165 ASSERT (GuidedEventContext);
166 CopyMem ((VOID *)NsCommBufferAddr, (CONST VOID *) GuidedEventContext, NsCommBufferSize);
167
168 Status = mMmst->MmFreePool ((VOID *) GuidedEventContext);
169 if (Status != EFI_SUCCESS) {
170 return EFI_OUT_OF_RESOURCES;
171 }
172 PerCpuGuidedEventContext[CpuNumber] = NULL;
173
174 return Status;
175 }
176
177 /**
178 Registers the MM foundation entry point.
179
180 @param [in] This Pointer to the MM Configuration protocol.
181 @param [in] MmEntryPoint Function pointer to the MM Entry point.
182
183 @retval EFI_SUCCESS Success.
184 **/
185 EFI_STATUS
186 EFIAPI
MmFoundationEntryRegister(IN CONST EFI_MM_CONFIGURATION_PROTOCOL * This,IN EFI_MM_ENTRY_POINT MmEntryPoint)187 MmFoundationEntryRegister (
188 IN CONST EFI_MM_CONFIGURATION_PROTOCOL *This,
189 IN EFI_MM_ENTRY_POINT MmEntryPoint
190 )
191 {
192 // store the entry point in a global
193 mMmEntryPoint = MmEntryPoint;
194 return EFI_SUCCESS;
195 }
196
197 /**
198 This function is the main entry point for an MM handler dispatch
199 or communicate-based callback.
200
201 @param DispatchHandle The unique handle assigned to this handler by
202 MmiHandlerRegister().
203 @param Context Points to an optional handler context which was
204 specified when the handler was registered.
205 @param CommBuffer A pointer to a collection of data in memory that will
206 be conveyed from a non-MM environment into an
207 MM environment.
208 @param CommBufferSize The size of the CommBuffer.
209
210 @return Status Code
211
212 **/
213 EFI_STATUS
214 EFIAPI
PiMmCpuTpFwRootMmiHandler(IN EFI_HANDLE DispatchHandle,IN CONST VOID * Context,OPTIONAL IN OUT VOID * CommBuffer,OPTIONAL IN OUT UINTN * CommBufferSize OPTIONAL)215 PiMmCpuTpFwRootMmiHandler (
216 IN EFI_HANDLE DispatchHandle,
217 IN CONST VOID *Context, OPTIONAL
218 IN OUT VOID *CommBuffer, OPTIONAL
219 IN OUT UINTN *CommBufferSize OPTIONAL
220 )
221 {
222 EFI_STATUS Status;
223 UINTN CpuNumber;
224
225 ASSERT (Context == NULL);
226 ASSERT (CommBuffer == NULL);
227 ASSERT (CommBufferSize == NULL);
228
229 CpuNumber = mMmst->CurrentlyExecutingCpu;
230 if (PerCpuGuidedEventContext[CpuNumber] == NULL) {
231 return EFI_NOT_FOUND;
232 }
233
234 DEBUG ((DEBUG_INFO, "CommBuffer - 0x%x, CommBufferSize - 0x%x\n",
235 PerCpuGuidedEventContext[CpuNumber],
236 PerCpuGuidedEventContext[CpuNumber]->MessageLength));
237
238 Status = mMmst->MmiManage (
239 &PerCpuGuidedEventContext[CpuNumber]->HeaderGuid,
240 NULL,
241 PerCpuGuidedEventContext[CpuNumber]->Data,
242 &PerCpuGuidedEventContext[CpuNumber]->MessageLength
243 );
244
245 if (Status != EFI_SUCCESS) {
246 DEBUG ((DEBUG_WARN, "Unable to manage Guided Event - %d\n", Status));
247 }
248
249 return Status;
250 }
251