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263559b8 | 1 | /** @file\r |
2 | \r | |
3 | Utility functions used by virtio device drivers.\r | |
4 | \r | |
5 | Copyright (C) 2012, Red Hat, Inc.\r | |
56f65ed8 | 6 | Portion of Copyright (C) 2013, ARM Ltd.\r |
263559b8 | 7 | \r |
8 | This program and the accompanying materials are licensed and made available\r | |
9 | under the terms and conditions of the BSD License which accompanies this\r | |
10 | distribution. The full text of the license may be found at\r | |
11 | http://opensource.org/licenses/bsd-license.php\r | |
12 | \r | |
13 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT\r | |
14 | WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
15 | \r | |
16 | **/\r | |
17 | \r | |
e371e7e5 | 18 | #include <Library/BaseLib.h>\r |
263559b8 | 19 | #include <Library/BaseMemoryLib.h>\r |
20 | #include <Library/DebugLib.h>\r | |
21 | #include <Library/MemoryAllocationLib.h>\r | |
e371e7e5 | 22 | #include <Library/UefiBootServicesTableLib.h>\r |
263559b8 | 23 | \r |
24 | #include <Library/VirtioLib.h>\r | |
25 | \r | |
26 | \r | |
27 | /**\r | |
28 | \r | |
56f65ed8 | 29 | Write a word into Region 0 of the device specified by VirtIo.\r |
263559b8 | 30 | \r |
31 | Region 0 must be an iomem region. This is an internal function for the\r | |
32 | driver-specific VIRTIO_CFG_WRITE() macros.\r | |
33 | \r | |
56f65ed8 | 34 | @param[in] VirtIo Target VirtIo device.\r |
263559b8 | 35 | \r |
36 | @param[in] FieldOffset Destination offset.\r | |
37 | \r | |
38 | @param[in] FieldSize Destination field size, must be in { 1, 2, 4, 8 }.\r | |
39 | \r | |
40 | @param[in] Value Little endian value to write, converted to UINT64.\r | |
41 | The least significant FieldSize bytes will be used.\r | |
42 | \r | |
43 | \r | |
56f65ed8 | 44 | @return Status code returned by VirtIo->Io.Write().\r |
263559b8 | 45 | \r |
46 | **/\r | |
263559b8 | 47 | EFI_STATUS\r |
9de0355b | 48 | EFIAPI\r |
56f65ed8 OM |
49 | VirtioWriteDevice (\r |
50 | IN VIRTIO_DEVICE_PROTOCOL *VirtIo,\r | |
51 | IN UINTN FieldOffset,\r | |
52 | IN UINTN FieldSize,\r | |
53 | IN UINT64 Value\r | |
263559b8 | 54 | )\r |
55 | {\r | |
56f65ed8 | 56 | return VirtIo->WriteDevice (VirtIo, FieldOffset, FieldSize, Value);\r |
263559b8 | 57 | }\r |
58 | \r | |
59 | \r | |
60 | /**\r | |
61 | \r | |
56f65ed8 | 62 | Read a word from Region 0 of the device specified by VirtIo.\r |
263559b8 | 63 | \r |
64 | Region 0 must be an iomem region. This is an internal function for the\r | |
65 | driver-specific VIRTIO_CFG_READ() macros.\r | |
66 | \r | |
56f65ed8 | 67 | @param[in] VirtIo Source VirtIo device.\r |
263559b8 | 68 | \r |
69 | @param[in] FieldOffset Source offset.\r | |
70 | \r | |
71 | @param[in] FieldSize Source field size, must be in { 1, 2, 4, 8 }.\r | |
72 | \r | |
73 | @param[in] BufferSize Number of bytes available in the target buffer. Must\r | |
74 | equal FieldSize.\r | |
75 | \r | |
76 | @param[out] Buffer Target buffer.\r | |
77 | \r | |
78 | \r | |
56f65ed8 | 79 | @return Status code returned by VirtIo->Io.Read().\r |
263559b8 | 80 | \r |
81 | **/\r | |
263559b8 | 82 | EFI_STATUS\r |
9de0355b | 83 | EFIAPI\r |
56f65ed8 OM |
84 | VirtioReadDevice (\r |
85 | IN VIRTIO_DEVICE_PROTOCOL *VirtIo,\r | |
86 | IN UINTN FieldOffset,\r | |
87 | IN UINTN FieldSize,\r | |
88 | IN UINTN BufferSize,\r | |
89 | OUT VOID *Buffer\r | |
263559b8 | 90 | )\r |
91 | {\r | |
56f65ed8 | 92 | return VirtIo->ReadDevice (VirtIo, FieldOffset, FieldSize, BufferSize, Buffer);\r |
263559b8 | 93 | }\r |
94 | \r | |
95 | \r | |
96 | /**\r | |
97 | \r | |
98 | Configure a virtio ring.\r | |
99 | \r | |
100 | This function sets up internal storage (the guest-host communication area)\r | |
101 | and lays out several "navigation" (ie. no-ownership) pointers to parts of\r | |
102 | that storage.\r | |
103 | \r | |
104 | Relevant sections from the virtio-0.9.5 spec:\r | |
105 | - 1.1 Virtqueues,\r | |
106 | - 2.3 Virtqueue Configuration.\r | |
107 | \r | |
108 | @param[in] The number of descriptors to allocate for the\r | |
109 | virtio ring, as requested by the host.\r | |
110 | \r | |
111 | @param[out] Ring The virtio ring to set up.\r | |
112 | \r | |
113 | @retval EFI_OUT_OF_RESOURCES AllocatePages() failed to allocate contiguous\r | |
114 | pages for the requested QueueSize. Fields of\r | |
115 | Ring have indeterminate value.\r | |
116 | \r | |
117 | @retval EFI_SUCCESS Allocation and setup successful. Ring->Base\r | |
118 | (and nothing else) is responsible for\r | |
119 | deallocation.\r | |
120 | \r | |
121 | **/\r | |
122 | EFI_STATUS\r | |
123 | EFIAPI\r | |
124 | VirtioRingInit (\r | |
125 | IN UINT16 QueueSize,\r | |
126 | OUT VRING *Ring\r | |
127 | )\r | |
128 | {\r | |
129 | UINTN RingSize;\r | |
130 | volatile UINT8 *RingPagesPtr;\r | |
131 | \r | |
132 | RingSize = ALIGN_VALUE (\r | |
133 | sizeof *Ring->Desc * QueueSize +\r | |
134 | sizeof *Ring->Avail.Flags +\r | |
135 | sizeof *Ring->Avail.Idx +\r | |
136 | sizeof *Ring->Avail.Ring * QueueSize +\r | |
137 | sizeof *Ring->Avail.UsedEvent,\r | |
138 | EFI_PAGE_SIZE);\r | |
139 | \r | |
140 | RingSize += ALIGN_VALUE (\r | |
141 | sizeof *Ring->Used.Flags +\r | |
142 | sizeof *Ring->Used.Idx +\r | |
143 | sizeof *Ring->Used.UsedElem * QueueSize +\r | |
144 | sizeof *Ring->Used.AvailEvent,\r | |
145 | EFI_PAGE_SIZE);\r | |
146 | \r | |
147 | Ring->NumPages = EFI_SIZE_TO_PAGES (RingSize);\r | |
148 | Ring->Base = AllocatePages (Ring->NumPages);\r | |
149 | if (Ring->Base == NULL) {\r | |
150 | return EFI_OUT_OF_RESOURCES;\r | |
151 | }\r | |
152 | SetMem (Ring->Base, RingSize, 0x00);\r | |
153 | RingPagesPtr = Ring->Base;\r | |
154 | \r | |
155 | Ring->Desc = (volatile VOID *) RingPagesPtr;\r | |
156 | RingPagesPtr += sizeof *Ring->Desc * QueueSize;\r | |
157 | \r | |
158 | Ring->Avail.Flags = (volatile VOID *) RingPagesPtr;\r | |
159 | RingPagesPtr += sizeof *Ring->Avail.Flags;\r | |
160 | \r | |
161 | Ring->Avail.Idx = (volatile VOID *) RingPagesPtr;\r | |
162 | RingPagesPtr += sizeof *Ring->Avail.Idx;\r | |
163 | \r | |
164 | Ring->Avail.Ring = (volatile VOID *) RingPagesPtr;\r | |
165 | RingPagesPtr += sizeof *Ring->Avail.Ring * QueueSize;\r | |
166 | \r | |
167 | Ring->Avail.UsedEvent = (volatile VOID *) RingPagesPtr;\r | |
168 | RingPagesPtr += sizeof *Ring->Avail.UsedEvent;\r | |
169 | \r | |
170 | RingPagesPtr = (volatile UINT8 *) Ring->Base +\r | |
171 | ALIGN_VALUE (RingPagesPtr - (volatile UINT8 *) Ring->Base,\r | |
172 | EFI_PAGE_SIZE);\r | |
173 | \r | |
174 | Ring->Used.Flags = (volatile VOID *) RingPagesPtr;\r | |
175 | RingPagesPtr += sizeof *Ring->Used.Flags;\r | |
176 | \r | |
177 | Ring->Used.Idx = (volatile VOID *) RingPagesPtr;\r | |
178 | RingPagesPtr += sizeof *Ring->Used.Idx;\r | |
179 | \r | |
180 | Ring->Used.UsedElem = (volatile VOID *) RingPagesPtr;\r | |
181 | RingPagesPtr += sizeof *Ring->Used.UsedElem * QueueSize;\r | |
182 | \r | |
183 | Ring->Used.AvailEvent = (volatile VOID *) RingPagesPtr;\r | |
184 | RingPagesPtr += sizeof *Ring->Used.AvailEvent;\r | |
185 | \r | |
186 | Ring->QueueSize = QueueSize;\r | |
187 | return EFI_SUCCESS;\r | |
188 | }\r | |
189 | \r | |
190 | \r | |
191 | /**\r | |
192 | \r | |
193 | Tear down the internal resources of a configured virtio ring.\r | |
194 | \r | |
195 | The caller is responsible to stop the host from using this ring before\r | |
196 | invoking this function: the VSTAT_DRIVER_OK bit must be clear in\r | |
197 | VhdrDeviceStatus.\r | |
198 | \r | |
199 | @param[out] Ring The virtio ring to clean up.\r | |
200 | \r | |
201 | **/\r | |
202 | VOID\r | |
203 | EFIAPI\r | |
204 | VirtioRingUninit (\r | |
205 | IN OUT VRING *Ring\r | |
206 | )\r | |
207 | {\r | |
208 | FreePages (Ring->Base, Ring->NumPages);\r | |
209 | SetMem (Ring, sizeof *Ring, 0x00);\r | |
210 | }\r | |
211 | \r | |
212 | \r | |
e371e7e5 | 213 | /**\r |
214 | \r | |
215 | Turn off interrupt notifications from the host, and prepare for appending\r | |
216 | multiple descriptors to the virtio ring.\r | |
217 | \r | |
218 | The calling driver must be in VSTAT_DRIVER_OK state.\r | |
219 | \r | |
f2965f4e | 220 | @param[in,out] Ring The virtio ring we intend to append descriptors to.\r |
e371e7e5 | 221 | \r |
222 | @param[out] Indices The DESC_INDICES structure to initialize.\r | |
223 | \r | |
224 | **/\r | |
225 | VOID\r | |
226 | EFIAPI\r | |
227 | VirtioPrepare (\r | |
228 | IN OUT VRING *Ring,\r | |
229 | OUT DESC_INDICES *Indices\r | |
230 | )\r | |
231 | {\r | |
232 | //\r | |
233 | // Prepare for virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device.\r | |
234 | // We're going to poll the answer, the host should not send an interrupt.\r | |
235 | //\r | |
236 | *Ring->Avail.Flags = (UINT16) VRING_AVAIL_F_NO_INTERRUPT;\r | |
237 | \r | |
238 | //\r | |
239 | // Prepare for virtio-0.9.5, 2.4.1 Supplying Buffers to the Device.\r | |
240 | //\r | |
635a3ca2 | 241 | // Since we support only one in-flight descriptor chain, we can always build\r |
242 | // that chain starting at entry #0 of the descriptor table.\r | |
243 | //\r | |
244 | Indices->HeadDescIdx = 0;\r | |
245 | Indices->NextDescIdx = Indices->HeadDescIdx;\r | |
e371e7e5 | 246 | }\r |
247 | \r | |
248 | \r | |
263559b8 | 249 | /**\r |
250 | \r | |
251 | Append a contiguous buffer for transmission / reception via the virtio ring.\r | |
252 | \r | |
635a3ca2 | 253 | This function implements the following section from virtio-0.9.5:\r |
263559b8 | 254 | - 2.4.1.1 Placing Buffers into the Descriptor Table\r |
263559b8 | 255 | \r |
256 | Free space is taken as granted, since the individual drivers support only\r | |
257 | synchronous requests and host side status is processed in lock-step with\r | |
258 | request submission. It is the calling driver's responsibility to verify the\r | |
259 | ring size in advance.\r | |
260 | \r | |
e371e7e5 | 261 | The caller is responsible for initializing *Indices with VirtioPrepare()\r |
262 | first.\r | |
263 | \r | |
11a5fdf4 | 264 | @param[in,out] Ring The virtio ring to append the buffer to, as a\r |
265 | descriptor.\r | |
266 | \r | |
267 | @param[in] BufferPhysAddr (Guest pseudo-physical) start address of the\r | |
268 | transmit / receive buffer.\r | |
269 | \r | |
270 | @param[in] BufferSize Number of bytes to transmit or receive.\r | |
271 | \r | |
272 | @param[in] Flags A bitmask of VRING_DESC_F_* flags. The caller\r | |
273 | computes this mask dependent on further buffers to\r | |
274 | append and transfer direction.\r | |
275 | VRING_DESC_F_INDIRECT is unsupported. The\r | |
276 | VRING_DESC.Next field is always set, but the host\r | |
277 | only interprets it dependent on VRING_DESC_F_NEXT.\r | |
278 | \r | |
279 | @param[in,out] Indices Indices->HeadDescIdx is not accessed.\r | |
280 | On input, Indices->NextDescIdx identifies the next\r | |
281 | descriptor to carry the buffer. On output,\r | |
282 | Indices->NextDescIdx is incremented by one, modulo\r | |
283 | 2^16.\r | |
263559b8 | 284 | \r |
285 | **/\r | |
286 | VOID\r | |
287 | EFIAPI\r | |
7fcacd6c | 288 | VirtioAppendDesc (\r |
e371e7e5 | 289 | IN OUT VRING *Ring,\r |
290 | IN UINTN BufferPhysAddr,\r | |
291 | IN UINT32 BufferSize,\r | |
292 | IN UINT16 Flags,\r | |
293 | IN OUT DESC_INDICES *Indices\r | |
263559b8 | 294 | )\r |
295 | {\r | |
296 | volatile VRING_DESC *Desc;\r | |
297 | \r | |
635a3ca2 | 298 | Desc = &Ring->Desc[Indices->NextDescIdx++ % Ring->QueueSize];\r |
263559b8 | 299 | Desc->Addr = BufferPhysAddr;\r |
300 | Desc->Len = BufferSize;\r | |
301 | Desc->Flags = Flags;\r | |
635a3ca2 | 302 | Desc->Next = Indices->NextDescIdx % Ring->QueueSize;\r |
e371e7e5 | 303 | }\r |
304 | \r | |
305 | \r | |
306 | /**\r | |
307 | \r | |
635a3ca2 | 308 | Notify the host about the descriptor chain just built, and wait until the\r |
309 | host processes it.\r | |
e371e7e5 | 310 | \r |
56f65ed8 | 311 | @param[in] VirtIo The target virtio device to notify.\r |
e371e7e5 | 312 | \r |
313 | @param[in] VirtQueueId Identifies the queue for the target device.\r | |
314 | \r | |
a7615fa8 | 315 | @param[in,out] Ring The virtio ring with descriptors to submit.\r |
e371e7e5 | 316 | \r |
a7615fa8 | 317 | @param[in] Indices Indices->NextDescIdx is not accessed.\r |
318 | Indices->HeadDescIdx identifies the head descriptor\r | |
319 | of the descriptor chain.\r | |
e371e7e5 | 320 | \r |
321 | \r | |
56f65ed8 | 322 | @return Error code from VirtIo->SetQueueNotify() if it fails.\r |
e371e7e5 | 323 | \r |
324 | @retval EFI_SUCCESS Otherwise, the host processed all descriptors.\r | |
325 | \r | |
326 | **/\r | |
327 | EFI_STATUS\r | |
328 | EFIAPI\r | |
329 | VirtioFlush (\r | |
56f65ed8 OM |
330 | IN VIRTIO_DEVICE_PROTOCOL *VirtIo,\r |
331 | IN UINT16 VirtQueueId,\r | |
332 | IN OUT VRING *Ring,\r | |
333 | IN DESC_INDICES *Indices\r | |
e371e7e5 | 334 | )\r |
335 | {\r | |
635a3ca2 | 336 | UINT16 NextAvailIdx;\r |
e371e7e5 | 337 | EFI_STATUS Status;\r |
338 | UINTN PollPeriodUsecs;\r | |
339 | \r | |
635a3ca2 | 340 | //\r |
341 | // virtio-0.9.5, 2.4.1.2 Updating the Available Ring\r | |
342 | //\r | |
343 | // It is not exactly clear from the wording of the virtio-0.9.5\r | |
344 | // specification, but each entry in the Available Ring references only the\r | |
345 | // head descriptor of any given descriptor chain.\r | |
346 | //\r | |
347 | NextAvailIdx = *Ring->Avail.Idx;\r | |
348 | Ring->Avail.Ring[NextAvailIdx++ % Ring->QueueSize] =\r | |
349 | Indices->HeadDescIdx % Ring->QueueSize;\r | |
350 | \r | |
e371e7e5 | 351 | //\r |
352 | // virtio-0.9.5, 2.4.1.3 Updating the Index Field\r | |
353 | //\r | |
354 | MemoryFence();\r | |
635a3ca2 | 355 | *Ring->Avail.Idx = NextAvailIdx;\r |
e371e7e5 | 356 | \r |
357 | //\r | |
358 | // virtio-0.9.5, 2.4.1.4 Notifying the Device -- gratuitous notifications are\r | |
359 | // OK.\r | |
360 | //\r | |
361 | MemoryFence();\r | |
56f65ed8 | 362 | Status = VirtIo->SetQueueNotify (VirtIo, VirtQueueId);\r |
e371e7e5 | 363 | if (EFI_ERROR (Status)) {\r |
364 | return Status;\r | |
365 | }\r | |
366 | \r | |
367 | //\r | |
368 | // virtio-0.9.5, 2.4.2 Receiving Used Buffers From the Device\r | |
369 | // Wait until the host processes and acknowledges our descriptor chain. The\r | |
370 | // condition we use for polling is greatly simplified and relies on the\r | |
371 | // synchronous, lock-step progress.\r | |
372 | //\r | |
373 | // Keep slowing down until we reach a poll period of slightly above 1 ms.\r | |
374 | //\r | |
375 | PollPeriodUsecs = 1;\r | |
376 | MemoryFence();\r | |
635a3ca2 | 377 | while (*Ring->Used.Idx != NextAvailIdx) {\r |
e371e7e5 | 378 | gBS->Stall (PollPeriodUsecs); // calls AcpiTimerLib::MicroSecondDelay\r |
379 | \r | |
380 | if (PollPeriodUsecs < 1024) {\r | |
381 | PollPeriodUsecs *= 2;\r | |
382 | }\r | |
383 | MemoryFence();\r | |
384 | }\r | |
385 | \r | |
dc9447bd | 386 | MemoryFence();\r |
e371e7e5 | 387 | return EFI_SUCCESS;\r |
263559b8 | 388 | }\r |