tsunami_io.hh revision 891 
1/*
2 * Copyright (c) 2003 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/* @file
30 * Tsunami Fake I/O Space mapping including RTC/timer interrupts
31 */
32
33#ifndef __TSUNAMI_DMA_HH__
34#define __TSUNAMI_DMA_HH__
35
36#include "mem/functional_mem/functional_memory.hh"
37#include "dev/tsunami.hh"
38
39/** How often the RTC interrupts */
40static const int RTC_RATE  = 1024;
41
42/*
43 * Tsunami I/O device is a catch all for all the south bridge stuff we care
44 * to implement.
45 */
46class TsunamiIO : public FunctionalMemory
47{
48  private:
49    /** The base address of this device */
50    Addr addr;
51
52    /** The size of mappad from the above address */
53    static const Addr size = 0xff;
54
55    struct tm tm;
56
57    /** In Tsunami RTC only has two i/o ports one for data and one for address,
58     * so you write the address and then read/write the data. This store the
59     * address you are going to be reading from on a read.
60     */
61    uint8_t RTCAddress;
62
63  protected:
64
65    /**
66     * The ClockEvent is handles the PIT interrupts
67     */
68    class ClockEvent : public Event
69    {
70      protected:
71        /** how often the PIT fires */
72        Tick interval;
73        /** The mode of the PIT */
74        uint8_t mode;
75        /** The status of the PIT */
76        uint8_t status;
77
78      public:
79        /**
80         * Just set the mode to 0
81         */
82        ClockEvent();
83
84        /**
85         * processs the timer event
86         */
87        virtual void process();
88
89        /**
90         * Returns a description of this event
91         * @return the description
92         */
93        virtual const char *description();
94
95        /**
96         * Schedule a timer interrupt to occur sometime in the future.
97         */
98        void Program(int count);
99
100        /**
101         * Write the mode bits of the PIT.
102         * @param mode the new mode
103         */
104        void ChangeMode(uint8_t mode);
105
106        /**
107         * The current PIT status.
108         * @return the status of the PIT
109         */
110        uint8_t Status();
111
112    };
113
114    /**
115     * Process RTC timer events and generate interrupts appropriately.
116     */
117    class RTCEvent : public Event
118    {
119      protected:
120          /** A pointer back to tsunami to create interrupt the processor. */
121          Tsunami* tsunami;
122      public:
123          /** RTC Event initializes the RTC event by scheduling an event
124           * RTC_RATE times pre second. */
125          RTCEvent(Tsunami* t);
126
127          /**
128           * Interrupth the processor and reschedule the event.
129           * */
130          virtual void process();
131
132          /**
133           * Return a description of this event.
134           * @return a description
135           */
136          virtual const char *description();
137    };
138
139    /** uip UpdateInProgess says that the rtc is updating, but we just fake it
140     * by alternating it on every read of the bit since we are going to
141     * override the loop_per_jiffy time that it is trying to use the UIP to
142     * calculate.
143     */
144    uint8_t uip;
145
146    /** Mask of the PIC1 */
147    uint8_t mask1;
148
149    /** Mask of the PIC2 */
150    uint8_t mask2;
151
152    /** Mode of PIC1. Not used for anything */
153    uint8_t mode1;
154
155    /** Mode of PIC2. Not used for anything */
156    uint8_t mode2;
157
158    /** Raw PIC interrupt register before masking */
159    uint8_t picr; //Raw PIC interrput register
160
161    /** Is the pic interrupting right now or not. */
162    bool picInterrupting;
163
164    /** A pointer to the Tsunami device which be belong to */
165    Tsunami *tsunami;
166
167    /**
168     * This timer is initilized, but after I wrote the code
169     * it doesn't seem to be used again, and best I can tell
170     * it too is not connected to any interrupt port
171     */
172    ClockEvent timer0;
173
174    /**
175     * This timer is used to control the speaker, which
176     * we normally could care less about, however it is
177     * also used to calculated the clockspeed and hense
178     * bogomips which is kinda important to the scheduler
179     * so we need to implemnt it although after boot I can't
180     * imagine we would be playing with the PC speaker much
181     */
182    ClockEvent timer2;
183
184    /** This is the event used to interrupt the cpu like an RTC.  */
185    RTCEvent rtc;
186
187    /** The interval is set via two writes to the PIT.
188     * This variable contains a flag as to how many writes have happened, and
189     * the time so far.
190     */
191    uint32_t timerData;
192
193
194  public:
195    /**
196     * Return the freqency of the RTC
197     * @return interrupt rate of the RTC
198     */
199    Tick  frequency() const { return RTC_RATE; }
200
201
202    /**
203     * Initialize all the data for devices supported by Tsunami I/O.
204     * @param name name of this device.
205     * @param t pointer back to the Tsunami object that we belong to.
206     * @param init_time Time (as in seconds since 1970) to set RTC to.
207     * @param a address we are mapped at.
208     * @param mmu pointer to the memory controller that sends us events.
209     */
210    TsunamiIO(const std::string &name, Tsunami *t, time_t init_time,
211              Addr a, MemoryController *mmu);
212
213    /**
214     * Create the tm struct from seconds since 1970
215     */
216    void set_time(time_t t);
217
218    /**
219      * Process a read to one of the devices we are emulating.
220      * @param req Contains the address to read from.
221      * @param data A pointer to write the read data to.
222      * @return The fault condition of the access.
223      */
224    virtual Fault read(MemReqPtr &req, uint8_t *data);
225
226    /**
227      * Process a write to one of the devices we emulate.
228      * @param req Contains the address to write to.
229      * @param data The data to write.
230      * @return The fault condition of the access.
231      */
232    virtual Fault write(MemReqPtr &req, const uint8_t *data);
233
234    /**
235     * Post an PIC interrupt to the CPU via the CChip
236     * @param bitvector interrupt to post.
237     */
238    void postPIC(uint8_t bitvector);
239
240    /**
241     * Clear a posted interrupt
242     * @param bitvector interrupt to clear
243     */
244    void clearPIC(uint8_t bitvector);
245
246    /**
247     * Serialize this object to the given output stream.
248     * @param os The stream to serialize to.
249     */
250    virtual void serialize(std::ostream &os);
251
252
253    /**
254     * Reconstruct the state of this object from a checkpoint.
255     * @param cp The checkpoint use.
256     * @param section The section name of this object
257     */
258    virtual void unserialize(Checkpoint *cp, const std::string &section);
259};
260
261#endif // __TSUNAMI_IO_HH__
262