summaryrefslogtreecommitdiff
path: root/UnixPkg/TimerDxe/Timer.c
blob: 5314d11ccdf3b08e182e5a6195b70c99edce0174 (plain)
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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
/*++

Copyright (c) 2004, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution.  The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

Module Name:

  Timer.c

Abstract:

  UNIX Emulation Timer Architectural Protocol Driver as defined in DXE CIS

  This Timer module uses an UNIX Thread to simulate the timer-tick driven
  timer service.  In the future, the Thread creation should possibly be
  abstracted by the CPU architectural protocol

--*/
#include "PiDxe.h"
#include <Protocol/Timer.h>
#include <Protocol/Cpu.h>
#include "Timer.h"
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/UefiLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include "UnixDxe.h"
#include <Library/UnixLib.h>

//
// Pointer to the CPU Architectural Protocol instance
//
EFI_CPU_ARCH_PROTOCOL   *mCpu;

//
// The Timer Architectural Protocol that this driver produces
//
EFI_TIMER_ARCH_PROTOCOL mTimer = {
  UnixTimerDriverRegisterHandler,
  UnixTimerDriverSetTimerPeriod,
  UnixTimerDriverGetTimerPeriod,
  UnixTimerDriverGenerateSoftInterrupt
};

//
// The notification function to call on every timer interrupt
//
EFI_TIMER_NOTIFY        mTimerNotifyFunction = NULL;

//
// The current period of the timer interrupt
//
UINT64                  mTimerPeriodMs;


VOID
EFIAPI
TimerCallback (UINT64 DeltaMs)
/*++

Routine Description:

  TODO: Add function description

Arguments:

  wTimerID  - TODO: add argument description
  msg       - TODO: add argument description
  dwUser    - TODO: add argument description
  dw1       - TODO: add argument description
  dw2       - TODO: add argument description

Returns:

  TODO: add return values

--*/
{
  EFI_TPL           OriginalTPL;
  EFI_TIMER_NOTIFY  CallbackFunction;


  OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);

  if (OriginalTPL < TPL_HIGH_LEVEL) {
    CallbackFunction = mTimerNotifyFunction;

    //
    // Only invoke the callback function if a Non-NULL handler has been
    // registered. Assume all other handlers are legal.
    //
    if (CallbackFunction != NULL) {
      CallbackFunction ((UINT64) (DeltaMs * 10000));
    }
  }

  gBS->RestoreTPL (OriginalTPL);

}

EFI_STATUS
EFIAPI
UnixTimerDriverRegisterHandler (
  IN EFI_TIMER_ARCH_PROTOCOL           *This,
  IN EFI_TIMER_NOTIFY                  NotifyFunction
  )
/*++

Routine Description:

  This function registers the handler NotifyFunction so it is called every time
  the timer interrupt fires.  It also passes the amount of time since the last
  handler call to the NotifyFunction.  If NotifyFunction is NULL, then the
  handler is unregistered.  If the handler is registered, then EFI_SUCCESS is
  returned.  If the CPU does not support registering a timer interrupt handler,
  then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler
  when a handler is already registered, then EFI_ALREADY_STARTED is returned.
  If an attempt is made to unregister a handler when a handler is not registered,
  then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to
  register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
  is returned.

Arguments:

  This           - The EFI_TIMER_ARCH_PROTOCOL instance.

  NotifyFunction - The function to call when a timer interrupt fires.  This
                   function executes at TPL_HIGH_LEVEL.  The DXE Core will
                   register a handler for the timer interrupt, so it can know
                   how much time has passed.  This information is used to
                   signal timer based events.  NULL will unregister the handler.

Returns:

  EFI_SUCCESS           - The timer handler was registered.

  EFI_UNSUPPORTED       - The platform does not support timer interrupts.

  EFI_ALREADY_STARTED   - NotifyFunction is not NULL, and a handler is already
                          registered.

  EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not
                          previously registered.

  EFI_DEVICE_ERROR      - The timer handler could not be registered.

--*/
{
  //
  // Check for invalid parameters
  //
  if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {
    return EFI_ALREADY_STARTED;
  }

  if (NotifyFunction == NULL) {
    /* Disable timer.  */
    gUnix->SetTimer (0, TimerCallback);
  } else if (mTimerNotifyFunction == NULL) {
    /* Enable Timer.  */
    gUnix->SetTimer (mTimerPeriodMs, TimerCallback);
  }
  mTimerNotifyFunction = NotifyFunction;

  return EFI_SUCCESS;
}

EFI_STATUS
EFIAPI
UnixTimerDriverSetTimerPeriod (
  IN EFI_TIMER_ARCH_PROTOCOL  *This,
  IN UINT64                   TimerPeriod
  )
/*++

Routine Description:

  This function adjusts the period of timer interrupts to the value specified
  by TimerPeriod.  If the timer period is updated, then the selected timer
  period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
  the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
  If an error occurs while attempting to update the timer period, then the
  timer hardware will be put back in its state prior to this call, and
  EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
  is disabled.  This is not the same as disabling the CPU's interrupts.
  Instead, it must either turn off the timer hardware, or it must adjust the
  interrupt controller so that a CPU interrupt is not generated when the timer
  interrupt fires.

Arguments:

  This        - The EFI_TIMER_ARCH_PROTOCOL instance.

  TimerPeriod - The rate to program the timer interrupt in 100 nS units.  If
                the timer hardware is not programmable, then EFI_UNSUPPORTED is
                returned.  If the timer is programmable, then the timer period
                will be rounded up to the nearest timer period that is supported
                by the timer hardware.  If TimerPeriod is set to 0, then the
                timer interrupts will be disabled.

Returns:

  EFI_SUCCESS      - The timer period was changed.

  EFI_UNSUPPORTED  - The platform cannot change the period of the timer interrupt.

  EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.

--*/
{

  //
  // If TimerPeriod is 0, then the timer thread should be canceled
  // If the TimerPeriod is valid, then create and/or adjust the period of the timer thread
  //
  if (TimerPeriod == 0
      || ((TimerPeriod > TIMER_MINIMUM_VALUE)
    && (TimerPeriod < TIMER_MAXIMUM_VALUE))) {
    mTimerPeriodMs = DivU64x32 (TimerPeriod + 5000, 10000);

    gUnix->SetTimer (mTimerPeriodMs, TimerCallback);
  }

  return EFI_SUCCESS;
}

EFI_STATUS
EFIAPI
UnixTimerDriverGetTimerPeriod (
  IN EFI_TIMER_ARCH_PROTOCOL            *This,
  OUT UINT64                            *TimerPeriod
  )
/*++

Routine Description:

  This function retrieves the period of timer interrupts in 100 ns units,
  returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
  is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
  returned, then the timer is currently disabled.

Arguments:

  This        - The EFI_TIMER_ARCH_PROTOCOL instance.

  TimerPeriod - A pointer to the timer period to retrieve in 100 ns units.  If
                0 is returned, then the timer is currently disabled.

Returns:

  EFI_SUCCESS           - The timer period was returned in TimerPeriod.

  EFI_INVALID_PARAMETER - TimerPeriod is NULL.

--*/
{
  if (TimerPeriod == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  *TimerPeriod = mTimerPeriodMs * 10000;

  return EFI_SUCCESS;
}

EFI_STATUS
EFIAPI
UnixTimerDriverGenerateSoftInterrupt (
  IN EFI_TIMER_ARCH_PROTOCOL  *This
  )
/*++

Routine Description:

  This function generates a soft timer interrupt. If the platform does not support soft
  timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
  If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
  service, then a soft timer interrupt will be generated. If the timer interrupt is
  enabled when this service is called, then the registered handler will be invoked. The
  registered handler should not be able to distinguish a hardware-generated timer
  interrupt from a software-generated timer interrupt.

Arguments:

  This  -  The EFI_TIMER_ARCH_PROTOCOL instance.

Returns:

  EFI_SUCCESS       - The soft timer interrupt was generated.

  EFI_UNSUPPORTEDT  - The platform does not support the generation of soft timer interrupts.

--*/
{
  return EFI_UNSUPPORTED;
}

EFI_STATUS
EFIAPI
UnixTimerDriverInitialize (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
/*++

Routine Description:

  Initialize the Timer Architectural Protocol driver

Arguments:

  ImageHandle - ImageHandle of the loaded driver

  SystemTable - Pointer to the System Table

Returns:

  EFI_SUCCESS           - Timer Architectural Protocol created

  EFI_OUT_OF_RESOURCES  - Not enough resources available to initialize driver.

  EFI_DEVICE_ERROR      - A device error occured attempting to initialize the driver.

--*/
{
  EFI_STATUS  Status;
  EFI_HANDLE  Handle;

  //
  // Make sure the Timer Architectural Protocol is not already installed in the system
  //
  ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiTimerArchProtocolGuid);

  //
  // Get the CPU Architectural Protocol instance
  //
  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (void *)&mCpu);
  ASSERT_EFI_ERROR (Status);

  //
  // Install the Timer Architectural Protocol onto a new handle
  //
  Handle = NULL;
  Status = gBS->InstallProtocolInterface (
                  &Handle,
                  &gEfiTimerArchProtocolGuid,
                  EFI_NATIVE_INTERFACE,
                  &mTimer
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Start the timer thread at the default timer period
  //
  Status = mTimer.SetTimerPeriod (&mTimer, DEFAULT_TIMER_TICK_DURATION);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  return EFI_SUCCESS;
}