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d401a487 AB |
1 | /** @file\r |
2 | Xen console SerialPortLib instance\r | |
3 | \r | |
4 | Copyright (c) 2015, Linaro Ltd. All rights reserved.<BR>\r | |
5 | \r | |
6 | This program and the accompanying materials\r | |
7 | are licensed and made available under the terms and conditions of the BSD License\r | |
8 | which accompanies this distribution. The full text of the license may be found at\r | |
9 | http://opensource.org/licenses/bsd-license.php\r | |
10 | \r | |
11 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
12 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
13 | \r | |
14 | **/\r | |
15 | \r | |
16 | #include <Base.h>\r | |
17 | #include <Uefi/UefiBaseType.h>\r | |
18 | \r | |
19 | #include <Library/BaseLib.h>\r | |
20 | #include <Library/SerialPortLib.h>\r | |
21 | #include <Library/XenHypercallLib.h>\r | |
22 | \r | |
23 | #include <IndustryStandard/Xen/io/console.h>\r | |
24 | #include <IndustryStandard/Xen/hvm/params.h>\r | |
25 | #include <IndustryStandard/Xen/event_channel.h>\r | |
26 | \r | |
c6d29726 AB |
27 | //\r |
28 | // We can't use DebugLib due to a constructor dependency cycle between DebugLib\r | |
29 | // and ourselves.\r | |
30 | //\r | |
31 | #define ASSERT(Expression) \\r | |
32 | do { \\r | |
33 | if (!(Expression)) { \\r | |
34 | CpuDeadLoop (); \\r | |
35 | } \\r | |
36 | } while (FALSE)\r | |
37 | \r | |
d401a487 AB |
38 | //\r |
39 | // The code below expects these global variables to be mutable, even in the case\r | |
40 | // that we have been incorporated into SEC or PEIM phase modules (which is\r | |
41 | // allowed by our INF description). While this is a dangerous assumption to make\r | |
42 | // in general, it is actually fine for the Xen domU (guest) environment that\r | |
43 | // this module is intended for, as UEFI always executes from DRAM in that case.\r | |
44 | //\r | |
45 | STATIC evtchn_send_t mXenConsoleEventChain;\r | |
46 | STATIC struct xencons_interface *mXenConsoleInterface;\r | |
47 | \r | |
c6d29726 AB |
48 | /**\r |
49 | Initialize the serial device hardware.\r | |
50 | \r | |
51 | If no initialization is required, then return RETURN_SUCCESS.\r | |
52 | If the serial device was successfully initialized, then return RETURN_SUCCESS.\r | |
53 | If the serial device could not be initialized, then return RETURN_DEVICE_ERROR.\r | |
54 | \r | |
55 | @retval RETURN_SUCCESS The serial device was initialized.\r | |
56 | @retval RETURN_DEVICE_ERROR The serial device could not be initialized.\r | |
57 | \r | |
58 | **/\r | |
d401a487 AB |
59 | RETURN_STATUS\r |
60 | EFIAPI\r | |
61 | SerialPortInitialize (\r | |
62 | VOID\r | |
63 | )\r | |
64 | {\r | |
48b3ff04 | 65 | if (! XenHypercallIsAvailable ()) {\r |
c6d29726 | 66 | return RETURN_DEVICE_ERROR;\r |
48b3ff04 LE |
67 | }\r |
68 | \r | |
d401a487 AB |
69 | if (!mXenConsoleInterface) {\r |
70 | mXenConsoleEventChain.port = (UINT32)XenHypercallHvmGetParam (HVM_PARAM_CONSOLE_EVTCHN);\r | |
71 | mXenConsoleInterface = (struct xencons_interface *)(UINTN)\r | |
72 | (XenHypercallHvmGetParam (HVM_PARAM_CONSOLE_PFN) << EFI_PAGE_SHIFT);\r | |
73 | \r | |
74 | //\r | |
75 | // No point in ASSERT'ing here as we won't be seeing the output\r | |
76 | //\r | |
77 | }\r | |
78 | return RETURN_SUCCESS;\r | |
79 | }\r | |
80 | \r | |
81 | /**\r | |
c6d29726 AB |
82 | Write data from buffer to serial device.\r |
83 | \r | |
84 | Writes NumberOfBytes data bytes from Buffer to the serial device.\r | |
85 | The number of bytes actually written to the serial device is returned.\r | |
86 | If the return value is less than NumberOfBytes, then the write operation failed.\r | |
87 | If Buffer is NULL, then ASSERT().\r | |
88 | If NumberOfBytes is zero, then return 0.\r | |
d401a487 | 89 | \r |
c6d29726 AB |
90 | @param Buffer Pointer to the data buffer to be written.\r |
91 | @param NumberOfBytes Number of bytes to written to the serial device.\r | |
d401a487 | 92 | \r |
c6d29726 AB |
93 | @retval 0 NumberOfBytes is 0.\r |
94 | @retval >0 The number of bytes written to the serial device.\r | |
95 | If this value is less than NumberOfBytes, then the write operation failed.\r | |
d401a487 AB |
96 | \r |
97 | **/\r | |
98 | UINTN\r | |
99 | EFIAPI\r | |
100 | SerialPortWrite (\r | |
101 | IN UINT8 *Buffer,\r | |
102 | IN UINTN NumberOfBytes\r | |
103 | )\r | |
104 | {\r | |
105 | XENCONS_RING_IDX Consumer, Producer;\r | |
106 | UINTN Sent;\r | |
107 | \r | |
c6d29726 AB |
108 | ASSERT (Buffer != NULL);\r |
109 | \r | |
110 | if (NumberOfBytes == 0) {\r | |
111 | return 0;\r | |
112 | }\r | |
113 | \r | |
d401a487 AB |
114 | if (!mXenConsoleInterface) {\r |
115 | return 0;\r | |
116 | }\r | |
117 | \r | |
c6d29726 AB |
118 | Sent = 0;\r |
119 | do {\r | |
120 | Consumer = mXenConsoleInterface->out_cons;\r | |
121 | Producer = mXenConsoleInterface->out_prod;\r | |
d401a487 | 122 | \r |
c6d29726 | 123 | MemoryFence ();\r |
d401a487 | 124 | \r |
c6d29726 AB |
125 | while (Sent < NumberOfBytes && ((Producer - Consumer) < sizeof (mXenConsoleInterface->out)))\r |
126 | mXenConsoleInterface->out[MASK_XENCONS_IDX(Producer++, mXenConsoleInterface->out)] = Buffer[Sent++];\r | |
d401a487 | 127 | \r |
c6d29726 | 128 | MemoryFence ();\r |
d401a487 | 129 | \r |
c6d29726 | 130 | mXenConsoleInterface->out_prod = Producer;\r |
d401a487 | 131 | \r |
d401a487 | 132 | XenHypercallEventChannelOp (EVTCHNOP_send, &mXenConsoleEventChain);\r |
c6d29726 AB |
133 | \r |
134 | } while (Sent < NumberOfBytes);\r | |
d401a487 AB |
135 | \r |
136 | return Sent;\r | |
137 | }\r | |
138 | \r | |
139 | /**\r | |
c6d29726 AB |
140 | Read data from serial device and save the datas in buffer.\r |
141 | \r | |
142 | Reads NumberOfBytes data bytes from a serial device into the buffer\r | |
143 | specified by Buffer. The number of bytes actually read is returned.\r | |
144 | If Buffer is NULL, then ASSERT().\r | |
145 | If NumberOfBytes is zero, then return 0.\r | |
d401a487 | 146 | \r |
c6d29726 AB |
147 | @param Buffer Pointer to the data buffer to store the data read from the serial device.\r |
148 | @param NumberOfBytes Number of bytes which will be read.\r | |
d401a487 | 149 | \r |
c6d29726 AB |
150 | @retval 0 Read data failed, no data is to be read.\r |
151 | @retval >0 Actual number of bytes read from serial device.\r | |
d401a487 AB |
152 | \r |
153 | **/\r | |
154 | UINTN\r | |
155 | EFIAPI\r | |
156 | SerialPortRead (\r | |
157 | OUT UINT8 *Buffer,\r | |
158 | IN UINTN NumberOfBytes\r | |
159 | )\r | |
160 | {\r | |
161 | XENCONS_RING_IDX Consumer, Producer;\r | |
162 | UINTN Received;\r | |
163 | \r | |
c6d29726 AB |
164 | ASSERT (Buffer != NULL);\r |
165 | \r | |
166 | if (NumberOfBytes == 0) {\r | |
167 | return 0;\r | |
168 | }\r | |
169 | \r | |
d401a487 AB |
170 | if (!mXenConsoleInterface) {\r |
171 | return 0;\r | |
172 | }\r | |
173 | \r | |
174 | Consumer = mXenConsoleInterface->in_cons;\r | |
175 | Producer = mXenConsoleInterface->in_prod;\r | |
176 | \r | |
177 | MemoryFence ();\r | |
178 | \r | |
179 | Received = 0;\r | |
180 | while (Received < NumberOfBytes && Consumer < Producer)\r | |
181 | Buffer[Received++] = mXenConsoleInterface->in[MASK_XENCONS_IDX(Consumer++, mXenConsoleInterface->in)];\r | |
182 | \r | |
183 | MemoryFence ();\r | |
184 | \r | |
185 | mXenConsoleInterface->in_cons = Consumer;\r | |
186 | \r | |
187 | XenHypercallEventChannelOp (EVTCHNOP_send, &mXenConsoleEventChain);\r | |
188 | \r | |
189 | return Received;\r | |
190 | }\r | |
191 | \r | |
192 | /**\r | |
c6d29726 | 193 | Polls a serial device to see if there is any data waiting to be read.\r |
d401a487 | 194 | \r |
c6d29726 AB |
195 | @retval TRUE Data is waiting to be read from the serial device.\r |
196 | @retval FALSE There is no data waiting to be read from the serial device.\r | |
d401a487 AB |
197 | \r |
198 | **/\r | |
199 | BOOLEAN\r | |
200 | EFIAPI\r | |
201 | SerialPortPoll (\r | |
202 | VOID\r | |
203 | )\r | |
204 | {\r | |
205 | return mXenConsoleInterface &&\r | |
206 | mXenConsoleInterface->in_cons != mXenConsoleInterface->in_prod;\r | |
207 | }\r |