xref: /openbmc/qemu/include/hw/misc/mips_itu.h (revision 77d361b1)
1 /*
2  * Inter-Thread Communication Unit emulation.
3  *
4  * Copyright (c) 2016 Imagination Technologies
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #ifndef MIPS_ITU_H
21 #define MIPS_ITU_H
22 
23 #include "hw/sysbus.h"
24 
25 #define TYPE_MIPS_ITU "mips-itu"
26 #define MIPS_ITU(obj) OBJECT_CHECK(MIPSITUState, (obj), TYPE_MIPS_ITU)
27 
28 #define ITC_CELL_DEPTH_SHIFT 2
29 #define ITC_CELL_DEPTH (1u << ITC_CELL_DEPTH_SHIFT)
30 
31 typedef struct ITCStorageCell {
32     struct {
33         uint8_t FIFODepth; /* Log2 of the cell depth */
34         uint8_t FIFOPtr; /* Number of elements in a FIFO cell */
35         uint8_t FIFO; /* 1 - FIFO cell, 0 - Semaphore cell */
36         uint8_t T; /* Trap Bit */
37         uint8_t F; /* Full Bit */
38         uint8_t E; /* Empty Bit */
39     } tag;
40 
41     /* Index of the oldest element in the queue */
42     uint8_t fifo_out;
43 
44     /* Circular buffer for FIFO. Semaphore cells use index 0 only */
45     uint64_t data[ITC_CELL_DEPTH];
46 
47     /* Bitmap tracking blocked threads on the cell.
48        TODO: support >64 threads ? */
49     uint64_t blocked_threads;
50 } ITCStorageCell;
51 
52 #define ITC_ADDRESSMAP_NUM 2
53 
54 typedef struct MIPSITUState {
55     /*< private >*/
56     SysBusDevice parent_obj;
57     /*< public >*/
58 
59     int32_t num_fifo;
60     int32_t num_semaphores;
61 
62     /* ITC Storage */
63     ITCStorageCell *cell;
64     MemoryRegion storage_io;
65 
66     /* ITC Configuration Tags */
67     uint64_t ITCAddressMap[ITC_ADDRESSMAP_NUM];
68     MemoryRegion tag_io;
69 } MIPSITUState;
70 
71 /* Get ITC Configuration Tag memory region. */
72 MemoryRegion *mips_itu_get_tag_region(MIPSITUState *itu);
73 
74 #endif /* MIPS_ITU_H */
75